Earthquakes on EARTH Magazine

Where fire freezes: All eyes, ears and instruments on Iceland's volatile volcanoes

Tue, 29 Mar 2016 18:35:15 -0400

In 1996, Grímsvötn Volcano erupted beneath the Vatnajökull Ice Cap, triggering a massive glacial outburst flood, called a jökulhlaup, that discharged 300,000 cubic meters per second as it flowed across the Skeidarársandur, a glacial outwash plain on the southern coast of Iceland. Credit: USGS/Icelandic Meteorological Office, Oddur Sigurdsson.

With examples of every type of volcano on Earth, and about a third of the island’s more than 30 active volcanic systems buried under glacial ice, Iceland earns its nickname: the land of fire and ice.

Vital seconds: The journey toward earthquake early warning for all

Thu, 03 Sep 2015 13:38:52 -0400

A mock-up of an earthquake early warning (EEW) alert on a cellphone. An EEW system is under development but not yet available to the public. Credit: K. Cantner, AGI, after Jennifer Strauss.

A ShakeAlert message like this would alert users to how many seconds they have before shaking waves arrive at their location and to the expected intensity of shaking. A shaking intensity of VI, as shown here, would mean the shaking would be strongly felt, people would find it difficult to stand, and structures could suffer damage. The warning message also displays a map with the location of the epicenter, the magnitude of the quake, and the current position of the P and S waves. Credit: USGS.

It is a cool foggy morning in San Mateo, Calif. A small ray of light has just peeked through my window. I listen to the birds chirping as I relish the final moments before my alarm calls for the start of a new day. It’s 6:15 a.m. Fifteen more minutes of a sleeping child.

Small tremor could have triggered big Chilean quake

Mon, 09 Mar 2015 11:54:20 -0400

Since 1900, many large earthquakes have occurred along the boundary where the Nazca Plate subducts below the South American Plate. Credit: Matthew Pritchard and Richard Allmendinger, Cornell University.

On April 1, 2014, a magnitude-8.2 earthquake shook the empty stretch of coast where Chile arcs into Peru, a region called the Iquique Gap. The gap is the only part of the 7,000 kilometer-long boundary between the Nazca and South American plates that hadn’t ruptured in the past century, despite a collision rate of almost 65 millimeters per year.

March 29, 1936: Notes on Earth's Inner Core

Fri, 30 Jan 2015 13:35:48 -0500

Inge Lehmann worked for the Royal Danish Geodetic Institute from 1925 to 1952, heading the seismology department from 1928 until her retirement. Credit: The Royal Library, National Library of Denmark and University of Copenhagen University Library.

On March 29, 1936, Danish seismologist Inge Lehmann wrote a letter to a colleague in which she argued that seismic waves — specifically P-waves — recorded from distant earthquakes showed some anomalous characteristics. “If you had seen so many records from these distances as I have,” she wrote, “I am sure you would not doubt that the amplitudes are abnormally small.” Within the year, Lehmann published a study based on those unusual amplitudes, work that first proposed that Earth has a solid inner core inside its liquid outer core.

Tohoku tsunami may have gotten a boost from submarine slump

Mon, 05 Jan 2015 13:33:39 -0500

The highest waves during the 2011 Tohoku tsunami occurred about 100 kilometers north of the main rupture. Credit: Kathleen Cantner, AGI.

When the magnitude-9 Tohoku earthquake hit Japan on March 11, 2011, the mainshock triggered tsunami waves averaging about 10 meters in height by the time they reached the coast of Japan, from Fukushima in the south to the northern tip of Honshu Island. But one mountainous stretch of coastline known as Sanriku, about 100 kilometers north of the main rupture area, saw waves higher than 40 meters. This oddity has led some scientists to suggest that a submarine landslide, triggered by the earthquake, may have contributed to the tsunami’s extreme height in this region.

Down to Earth With: Brian Tucker

Thu, 18 Dec 2014 10:40:34 -0500

Brian Tucker, founder and president of GeoHazards International (GHI). Credit: courtesy of the MacArthur Foundation.

Some of the world’s most densely populated cities are at highest risk for earthquake-related disasters. Geophysicist Brian Tucker has spent the last two-plus decades trying to help the developing world avoid such disasters, and in 1991, he founded the nonprofit GeoHazards International (GHI) to bring the developed world’s risk-mitigation techniques to high-risk communities in the developing world.

Hazard lingers after South Napa earthquake

Wed, 17 Dec 2014 13:36:10 -0500

A damaged building in Napa, Calif., following the magnitude-6 earthquake on Aug. 24, 2014, which struck south of the city. Credit: ©James Gunn, CC BY 2.0.

San Francisco — The magnitude-6 earthquake that shook buildings and rattled wineries in California’s Napa Valley on Aug. 24, 2014, continues to affect homes in at least one neighborhood in the city of Napa more than three months later. The quake’s epicenter was about 6 kilometers south of the city, but post-quake movement, or afterslip, along the principal fault line to the north of the epicenter is ongoing, according to a fast-track report prepared by the U.S. Geological Survey (USGS) for the Federal Emergency Management Agency. Scientists involved in producing the 51-page report — released to the public on Tuesday — discussed it at a press conference at the annual meeting of the American Geophysical Union in San Francisco.

Lead-up to Icelandic earthquakes seen in groundwater chemistry

Tue, 09 Dec 2014 10:47:18 -0500

The Husavik-Flatey Fault cuts across part of northern Iceland near the town of Husavik. An earthquake on this fault in 2012 was one of two found recently to correlate with significant changes in groundwater chemistry measured months before the quakes occurred. Credit: Alasdair Skelton.

Scientists tracking groundwater in Iceland have reported that significant shifts in the water’s chemistry occurred months prior to earthquakes in 2012 and 2013. It’s far too early to apply the findings to earthquake hazard assessment, researchers say, but the results suggest that precursory groundwater changes may also herald earthquakes elsewhere and point toward a potential means of future seismic monitoring.

Snow triggers quakes on Mount Rainier

Tue, 04 Nov 2014 11:41:58 -0500

Credit: ©Shutterstock.com/Bryan Brazil.

A new study indicates that more than 150,000 low-frequency earthquakes that occurred on Mount Rainier over the past decade were caused by snowfall that triggered stick-slip sliding of glaciers.

The quakes, which were too small to be felt, occurred in winter at elevations of 3,000 meters or more and repeated at regular intervals, as often as every few minutes. These “ice quakes” were clustered in week- to month-long swarms that strongly correlated with snowfall events, reported Kate Allstadt and Stephen D. Malone of the University of Washington in the Journal of Geophysical Research – Earth Surface.

Inland earthquake triggers distant tsunami

Mon, 03 Nov 2014 20:32:31 -0500

On Sept. 24, 2013, a magnitude-7.7 earthquake struck southern Pakistan, killing more than 800 people. The quake made global headlines in part due to the birth of a small island it triggered just off the coast — a mound of mud dubbed Quake Island that has since washed away. A new study has found evidence of another curious event linked to the quake: a small tsunami that appears to have been remotely triggered by a submarine landslide far from the earthquake’s inland epicenter.

Benchmarks: December 26, 2004: Indian Ocean tsunami strikes

Mon, 03 Nov 2014 13:15:49 -0500

Destruction from the tsunami extended hundreds of meters inland and stretched for thousands of kilometers. Credit: Photographer's Mate 1st Class Jon Gesch, USN.

On Dec. 26, 2004, a magnitude-9.2 earthquake ruptured the seafloor off Indonesia, sending the most destructive tsunami in recorded history across the Indian Ocean. A wall of water and debris slammed the shores of South Asia; some witnesses described it as sounding like a freight train. Tourists and locals alike scrambled to safety inland and atop tall hotels, recording videos of the surging water that inundated their communities. Many were unable to reach higher ground.

Seismic friction causes fault iridescence

Mon, 06 Oct 2014 09:58:56 -0400

Geologist Mitch Prante examines thin hematite layers on a fault surface that recorded ancient seismicity in the Wasatch Fault Zone in Utah. Credit: Jim Evans.

Although iridescent spots on rocks in Utah’s Wasatch Fault Zone were first recognized two decades ago, scientists haven’t understood their origin, until now. New research shows that the iridescence appears on fault surfaces subjected to flash heating from friction and that the spots can provide clues to ancient seismic events.

Russian earthquake ruptures superfast and deep

Mon, 06 Oct 2014 09:31:09 -0400

Credit: Wikimedia Commons/Aivazovsky

A “superfast” magnitude-6.7 earthquake was detected off the coast of Kamchatka, Russia, in May. The earthquake, called a “supershear” quake, is one of a handful of superfast earthquakes noted by researchers over the years, but this is the first identified at such great depth.

Casting a seismic shadow

Thu, 02 Oct 2014 13:22:09 -0400

Credit: Kathleen Cantner, AGI.

In the week or two before the magnitude-8.6 Indian Ocean earthquake in 2012, Earth was unusually quiet, with few large quakes over magnitude 5. Afterward, seismic activity all over the globe was elevated for more than a week. Then, suddenly, global seismicity dropped off precipitously: Beginning two weeks after the mainshock, no earthquakes of magnitude-6.5 or greater occurred for 95 days.

Triggered tremor along the San Andreas Fault

Thu, 02 Oct 2014 13:14:29 -0400

The San Andreas Fault (SAF) in California is one of the most active in the U.S., but the 1,300-kilometer-long strike-slip fault seems to only be susceptible to small-scale dynamic triggering. After the magnitude-9 Tohoku quake in Japan in 2011, the SAF experienced an elevated incidence of tremor up and down its length. The tiny tremors were recorded at depths between 16 and 30 kilometers, below the fault’s seismogenic zone.

Remote triggering of ice quakes

Thu, 02 Oct 2014 12:19:30 -0400

The HOWD seismic station in Antarctica where ice quakes were measured following the Maule earthquake in Chile. Credit: Erik Kendrick, Ohio State University.

On Feb. 27, 2010, a magnitude-8.8 earthquake struck the subduction zone off the coast of Chile. The resulting Rayleigh surface waves rippled around the world, triggering small earthquakes in many different tectonic settings, including Antarctica. As the surface waves moved across the white continent, a third of Antarctic seismic stations reported shaking coming from so-called “ice quakes.”

We're all living in the global aftershock zone

Thu, 02 Oct 2014 11:34:29 -0400

Credit: Kathleen Cantner, AGI.

When large back-to-back earthquakes hit Earth — and the headlines — many people wonder if the events are linked. Can one earthquake trigger another hundreds or even thousands of kilometers away? The answer, scientists say, is yes, although it appears the hazards of such triggering may not be that dangerous.

Alaskan megathrust fault more active under Kodiak

Wed, 03 Sep 2014 08:12:33 -0400

This road along Womens Bay on Kodiak Island is in an area that subsided nearly 2 meters during the 1964 earthquake. Credit: U.S. Geological Survey Photographic Library.

In 1964, a magnitude-9.2 earthquake ruptured two segments of the Alaskan megathrust fault along more than 900 kilometers from Prince William Sound to Kodiak Island. Historical and paleoseismic evidence has hinted at previous events in this region in 1788 and about 1100, and now a team working on Kodiak Island has found clues of another large event that struck about 500 years ago. The find makes the recurrence interval for the tsunami-producing fault much shorter, potentially increasing the earthquake and tsunami hazard profile, not only for Alaska, but also Hawaii and California.

Human-induced earthquakes shake less

Thu, 21 Aug 2014 12:16:09 -0400

Occurrences of earthquakes in the Central and Eastern United States have increased since 2009 — a phenomenon that many scientists attribute to the growing use of hydraulic fracturing for fossil fuel extraction. Most agree that it’s not the fracturing itself, but the reinjection of wastewater into wells for containment beneath the surface that tends to induce seismic activity. Now, new research looking at the effects of induced seismic activity suggests that human-made earthquakes and naturally occurring tectonic earthquakes are felt differently at the surface.

In Turkey, the older the fault, the bigger the quake: Good news for Istanbul?

Tue, 19 Aug 2014 11:18:34 -0400

The North Anatolian Fault Zone is one of the most active, and potentially deadly, fault zones in the world. Credit: Kathleen Cantner, AGI.

For decades, Istanbul has been bracing for a major earthquake from the dangerously active North Anatolian Fault, which passes just 20 kilometers south of Turkey’s largest city. A new study looking at the age of the fault zone may set a cap on the maximum quake size that could hit Istanbul, suggesting that the older, more mature sections of the zone in the east are capable of bigger earthquakes than the younger sections in the west, which are near the city.

The Bay Area's next 'big one' could strike as a series of quakes

Thu, 07 Aug 2014 12:58:42 -0400

Credit: drumbo/www.flickr.com via Creative Commons.

The San Andreas Fault is the most notorious fault in the San Francisco Bay Area, but other principal faults could also pose a significant threat to the region. Credit: Kathleen Cantner, AGI.

Californians are bracing for when the San Andreas Fault unleashes the next “big one,” but a new study looking at the paleoseismic history of the San Francisco Bay Area suggests that accumulated stress could also be released in a series of moderate to large quakes on satellite faults, rather than by a single great event on the San Andreas.

Books: The once and future San Andreas Fault

Mon, 28 Jul 2014 13:04:35 -0400

"Earthquake Storms: The Fascinating History and Volatile Future of the San Andreas Fault," by John Dvorak, Pegasus, 2014, ISBN: 978-1605984957.

One of the most famous pictures of the San Andreas Fault — taken by G.K. Gilbert, the pioneering geologist whose late-19th century insights into faults and the earthquake cycle were close to prescient — shows a woman standing next to the ruptured fault immediately after the 1906 earthquake.

Are slow-slip earthquakes under Tokyo stressing faults?

Mon, 21 Jul 2014 15:33:45 -0400

Japan sits at the intersection of multiple tectonic plates. Just east of the island is a deep trench called the Sagami Trough. To monitor slow slip in the region, scientists are tracking the surface motion of the Boso Peninsula on the eastern side of Tokyo Bay, where the Philippine Plate plunges beneath the Eurasian Plate, creating the trough. Credit: Kathleen Cantner, AGI, after Ozawa et al., Geophysical Research Letters (2014).

To study plate movements under Tokyo, Shinzaburo Ozawa of the Geospatial Information Authority of Japan in Tsukuba used GPS sensors to track the surface motion of the Bōsō Peninsula on the eastern side of Tokyo Bay, where the Philippine Plate plunges beneath the Eurasian Plate, creating the Sagami Trough. His results were published in Geophysical Research Letters.

Striped pyrites link earthquakes to gold deposition

Thu, 10 Jul 2014 15:11:36 -0400

Researchers have linked pyrite in the Porgera gold mine in Papua New Guinea to the so-called fault-valve process of gold deposit formation. Credit: Richard Farbelini.

Pyrite, or “fool’s gold,” is an iron sulfide mineral commonly found in hydrothermal ore deposits. In such deposits, gold atoms can substitute for iron in the structure of pyrite, so pyrite crystals in gold mines often contain portions of the precious metal. Eleanor Peterson, a student at the Australian National University (ANU) in Canberra, and her advisor, John Mavrogenes, an economic geologist also at ANU, analyzed pyrites from the Porgera mine in Papua New Guinea, where quartz veins in the Roamane Fault Zone host high-grade gold ores.

People's earthquake reports influenced more by locomotion than location

Thu, 10 Jul 2014 13:11:55 -0400

Intensity surveys help geologists study earthquakes. This map compiles all responses to the U.S. Geological Survey's Did You Feel It? survey between 1994 and 2012. Credit: USGS

Intensity scales like the Modified Mercalli scale, used in the U.S., and the European Macroseismic scale measure the strength of shaking produced by an earthquake at a certain location, as determined from surveys assessing the effects on people, structures and the natural environment. For example, a II on the Modified Mercalli scale is: “Felt only by a few persons at rest, especially on upper floors of buildings,” whereas a V is “felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable objects overturned. Pendulum clocks may stop.”

San Andreas Fault shook Bay Area three times in a century

Mon, 23 Jun 2014 15:52:53 -0400

Ashley Streig and her colleagues examined tree stumps among other proxies. Tree-ring dating indicates this tree was cut prior to the earthquake of 1838 on the San Andreas Fault in the Santa Cruz Mountains. Credit: University of Oregon.

“This project took a lot of footwork,” says Ashley Streig, a paleoseismologist at the University of Oregon and lead author of the new study, published in the Bulletin of the Seismological Society of America. Using historical records, including written accounts of earthquake damage to Spanish-built missions in the area, Streig and colleagues identified and mapped the active fault trace through the Santa Cruz Mountains using both field reconnaissance and airborne Lidar.

Longmenshan fault zone in the spotlight after two major quakes in five years

Thu, 15 May 2014 09:46:06 -0400

Credit: David Wald, USGS

In May 2008, a magnitude-7.9 earthquake struck near Wenchuan, China, killing more than 80,000 people in the country’s biggest quake since 1950. Then, in April 2013, the magnitude-6.6 Lushan earthquake hit just 90 kilometers to the south — also within China’s Longmenshan Fault Zone, which separates the Tibetan Plateau to the west from the Sichuan Basin to the east — and caused another 200 deaths. Now, scientists have found that a roughly 60-kilometer segment of the fault zone between the epicenters of the two big temblors could be the next to rupture, although no one knows when or how big it might be.

Humans causing California's mountains to grow

Wed, 14 May 2014 09:56:28 -0400

A study of more than 500 GPS stations in Southern California and Nevada found an anthropogenic signal in uplift of the Sierra Nevada and the California Coast Ranges related to long-term water withdrawal from aquifers in the San Joaquin Valley. Credit: UNAVCO

Humankind has proven time and again that it can reshape mountains, or even tear them down. Now, it appears, we can make them rise as well. Geologists studying growth rates of the Sierra Nevada and of central California’s Coast Ranges have identified an anthropogenic contribution to the mountains’ uplift that they suggest is tied to the decades-long depletion of groundwater in the state’s Central Valley. What’s more, the researchers report in a study published today in Nature, the long-term water loss may be affecting how stress builds up on faults like the San Andreas.

Faking quakes at full scale: Giant shake tables simulate earthquakes to make buildings safer

Fri, 11 Apr 2014 13:29:41 -0400

The largest shake table experiment ever conducted shook this full-size seven-story condominium built at the Japanese National Research Institute for Earth Science and Disaster Prevention's Earth-Defense facility ("E-Defense") in 2009. Credit: John van de Lindt

On a muggy day in mid-July 2009, a lone seven-story condominium complex northwest of Kobe, Japan, was violently shaken by seismic forces similar to those that struck Northridge, Calif., in 1994 — only stronger. Onlookers watched the 23-unit, wood-frame tower sway and bounce while, inside the building, furniture toppled and plates clattered to the floor.

Massive earthquake strikes Chile

Wed, 02 Apr 2014 01:56:10 -0400

This ShakeMap shows the intensity of the magnitude-8.2 Chile quake. Yellows and reds indicate more intense shaking.

Update (April 2, 2014 9:49 a.m. EDT): As of Wednesday morning, many of the more than 900,000 people who evacuated from coastal areas of northern Chile were returning to their homes following yesterday evening’s magnitude-8.2 earthquake, which hit 95 kilometers northwest of the city of Iquique. Damage in the region appears relatively light given the size of the tremor based on reports, although full assessments are still underway. Adobe homes in the town of Arica were reportedly destroyed, and elsewhere, landslides blocked and damaged some roadways. Six deaths have been attributed to the quake, according to Chilean authorities, including individuals who were killed by falling debris and at least two who suffered heart attacks. Roughly 300 prisoners are said to have escaped from a female prison in Iquique, some of whom have been taken back into custody. Shaking from the earthquake was felt as far away as La Paz, Bolivia, some 450 kilometers from the epicenter.

Seattle's landslide risk greater than thought

Thu, 20 Feb 2014 12:17:34 -0500

This Seattle area map shows the location of the Seattle Fault Zone (dotted line), the fault location used for the rupture model for landslide simulation (line of triangles), and landslide-prone areas designated by the city. The inset map shows the regional tectonic setting and volcanoes (triangles). Allstadt et al., BSSA 2013 ©Seismological Society of America

Landslides have been part of Seattle’s history “from a time to which the memory of man runneth not back,” wrote famed city engineer Reginald Thomson in 1897. A new study shows that landslides will also play a central role long into the future. They will be “extensive and potentially devastating, causing direct losses and impeding recovery,” reported a team in Bulletin of the Seismological Society of America.

Benchmarks: March 27, 1964: The Good Friday Alaska Earthquake and Tsunamis

Thu, 20 Feb 2014 12:02:22 -0500

Government Hill Elementary School in Anchorage was destroyed by the Government Hill landslide during the earthquake. USGS Photographic Library

During the Cold War, many Americans lived in fear of the day their town would be shaken by an atomic bomb blast. On Good Friday 1964, some Alaskans thought that day had come.

Hazards abroad: Sent home

Tue, 10 Dec 2013 10:08:22 -0500

On May 19, 2012, seismologist Roger Bilham of the University of Colorado at Boulder landed at the airport in Delhi, India, on his way to Bhutan. He debarked from the plane and was met by Indian customs officials, who declared he was on the “blacklist” and not allowed entry to India, despite having a valid visa. Two hours later, he was on a plane heading back to the U.S.

Giant quake sloshed fjords half a world away

Wed, 20 Nov 2013 11:43:45 -0500

On the morning of March 11, 2011, Leif Hus and his wife Gry Melas Hus were having breakfast in their kitchen overlooking Sognefjord in Leikanger, Norway. It was low tide on a calm and windless day with near-freezing temperatures. As they stood, coffee cups in hand, looking out the window at the fjord, they saw an unusual wave roll in. The wave continued to rise, surging over the seawall into their backyard before receding back into the fjord. Then another wave surged in, and another. As the water rose, engulfing the ladder on their dock, Leif grabbed his cell phone and started filming.

Old photos help scientists relocate 1906 San Francisco quake rupture point

Wed, 20 Nov 2013 11:28:18 -0500

The buttons being in their proper place on the right-hand side of the man's waistcoat indicate that this 1906 photo has not been reversed during the printing process, providing an important clue as to the orientation of the fault trace, seen at the couple's feet. Bancroft Library, University of California, Berkeley

Portola Valley, just south of San Francisco, is famous for its progressive approach to geology. The town was the subject of the first geologic map of California and the first municipality in the state to hire its very own resident geologist. There’s a good reason: The section of the San Andreas Fault that produced the deadly San Francisco quake of 1906 runs right through the town. But where exactly the fault trace lies has long been a mystery. Now, in a new study, researchers have used a combination of new technology and old photographs to relocate the fault line.

A public service announcement: Improve geologic literacy starting on the home front

Mon, 18 Nov 2013 14:22:48 -0500

Hiking around the Sheep Rock Unit at John Day Fossil Beds National Monument in eastern Oregon provides a full day of geologic adventures. Megan Sever

It's also nice to know a little something about the geology of where you vacation, such as when the last eruption on Maui occurred. While on a tour in May, the guides asked, "So, is anyone here a geologist?" I tentatively raised my hand. "Oh no, now she can fact-check what we say," they replied. No need — they had done their homework and knew a lot about the geology of the area! @Griff, Aloha Kayaks Maui

Jim Sever

Earlier this fall, I took a paddleboarding tour along the Willamette River to Willamette Falls near Oregon City, Ore., a Portland suburb famous for marking the end of the Oregon Trail. Willamette Falls, as I learned, is one of the largest waterfalls in the U.S. My tour guides, a couple of young and knowledgeable self-described river rats, explained how the falls were used for hydroelectric power generation and how the locks worked. But they didn’t tell us anything about how or when the falls formed or about the massive basalts responsible for their grandeur.

Slab tear explains perplexing Colombian earthquake activity

Fri, 08 Nov 2013 10:08:56 -0500

Four plates converge at the northwest corner of Colombia, leading to a complicated pattern of earthquake activity. Kathleen Cantner, AGI

Colombia sits atop a restless intersection of tectonic plates: The Caribbean Plate is subducting along the country’s northern coast while the oceanic Nazca Plate subducts along its western edge. In between, the narrow but buoyant Isthmus of Panama continues to crash into South America like a battering ram. The complex pattern of earthquake activity produced by these disparate forces has long confounded scientists hoping to decipher the plate structure beneath Colombia. In a new study, researchers have identified a feature called the Caldas Tear that may explain many long-standing riddles of Colombia’s geology.

World's largest deep earthquake recorded

Tue, 29 Oct 2013 17:06:02 -0400

The seismology world may have a new leader in superlatives: On May 24, 2013, the largest, deep earthquake ever recorded struck beneath the Sea of Okhotsk, between the Kamchatka Peninsula and Russian mainland. Scientists are still puzzling over how such a large event could occur so deep.

Scientists demonstrate strengths and shortcomings of method for determining ancient earthquake size

Mon, 09 Sep 2013 15:07:27 -0400

“A giant Cascadia earthquake, with its accompanying tsunami, has the potential to be the biggest natural disaster in this history of the U.S.,” says Simon Engelhart, a seismologist at the University of Rhode Island. On Jan. 26, 1700, a magnitude-9 earthquake associated with the nearby Cascadia Subduction Zone struck the Pacific Northwest. The quake created tsunami waves that left deposits on shorelines as far away as Japan and caused parts of the Pacific shoreline to sink half a meter into the sea. Such a quake will happen again; the question is when. Researchers are attempting to determine how often earthquakes occurred in the past to estimate when the next quake is likely to occur. New experimental research off the coast of Oregon that demonstrates the accuracy of a method for determining the vertical deformation associated with past earthquakes may help scientists answer this question.

Alaskan volcano doesn't just huff and puff, it screams

Tue, 16 Jul 2013 12:50:55 -0400

In March 2009, Alaska’s Mount Redoubt awoke from two decades of silence with something to say: A series of small earthquakes leading up to the eruption produced a seismic sound that staff at the U.S. Geological Survey's Alaska Volcano Observatory nicknamed “the screams.” Now, two new studies are eavesdropping on Redoubt’s inner workings and quantifying the forces needed to produce the unusual harmonic tremors.

Big quakes topple traditional views of fault behavior

Fri, 15 Mar 2013 11:26:46 -0400

Heavy damage was sustained on the Japanese coast, as seen here in Sukuiso, following the magnitude-9 Tohoku earthquake in March 2011. During the quake, a rupture might have been triggered on a slow-moving part of the nearby megathrust fault by heating and pressurization of fluids within the fault. U.S. Navy photo by Mass Communication Specialist 3rd Class Dylan McCord

The oceanic Indo-Australian Plate moves diagonally (purple arrow) with respect to the Sunda Megathrust, subducting beneath the overriding Sunda Plate at an oblique angle. Some of the motion associated with the subduction is oriented perpendicular (red arrows) to the trench, meaning that stress accumulates on the plate interface and occasionally results in megathrust earthquakes. But there is also motion of the Indo-Australian Plate in the direction parallel to the trench (thin blue arrow), resulting in an accumulation of stress on strike-slip faults (oppositely oriented blue arrows) either on the overriding plate — as in the Great Sumatran Fault — or on the oceanic plate. AGI, after Ishii et al., Geology, 2013

If rules are made to be broken, then perhaps conventional wisdom is made to be overturned. The spate of large earthquakes in recent years — the magnitude and location of which have defied scientific expectations in several cases — has provided ample support for these maxims, at least within earth science. For all the confusion, though, data emerging from these events are reshaping and improving our understanding of how faults operate.

Setting sail on unknown seas: The past, present and future of species rafting

Mon, 11 Feb 2013 09:23:37 -0500

This map portrays a few examples of modern animals whose ancestors dispersed by voyaging on natural rafts across open water, including lemurs, which rafted from Africa to Madagascar, and chameleons, which rafted from Madagascar to islands in the Indian Ocean. Rafting routes are delineated by the green arrows. Kathleen Cantner, AGI

Removal of the dock at Agate Beach was a public process; people were very interested in its progress. Courtesy of the Oregon Parks and Recreation Department

A section of the dock will be preserved in Newport, Ore., as a memorial to the victims of the earthquake and tsunami. Courtesy of the Oregon Parks and Recreation Department

Examining the dock that washed up on the coast of Washington in December posed quite a challenge: Researchers had to ford deep, cold streams, hike through forests and across logs and use a rope line to descend to the beach. Courtesy of the National Park Service and the Washington Department of Ecology

On June 5, 2012, several thousand castaways rode a massive boxcar-sized dock to landfall on Oregon’s Agate Beach, just north of Newport. A plaque on the side, written in Japanese, revealed an unprecedented journey: The dock had been unmoored from the Japanese coastal city of Misawa during the catastrophic tsunami on March 11, 2011.

Superquakes, supercycles, and global earthquake clustering: Recent research and recent quakes reveal surprises in major fault systems

Mon, 03 Dec 2012 17:53:20 -0500

A village near the coast of Sumatra after the tsunami that struck Southeast Asia the day after Christmas 2004. U.S. Navy photo by Photographer's Mate 2nd Class Philip A. McDaniel

Scientists can use turbidites (submarine slope failure deposits) collected from the ocean floor to understand past earthquakes. Turbidites provide clues to the timing and magnitude of past events. The authors have collected turbidites from 6,000 meters below the sea surface off the coast of Sumatra and 3,000 meters deep in the Cascadia Subduction Zone in the Pacific Northwest. Kathleen Cantner, AGI

The historic seismic record from the Cascadia Subduction Zone is no longer limited to instrumental earthquake data (blue dots). It has been extended by the association of mega earthquakes with turbidite deposits identified in offshore sediment cores (orange dots). Kathleen Cantner, AGI

The Oregon State University coring team examines the upper section of a turbidite core recovered off the Sumatran margin. Chris Aikenhead

Recent surprising earthquakes in Japan, Sumatra and the Queen Charlotte Islands (circles), as well as new research along the Cascadia Subduction Zone (triangle), indicate that most any fault zone could rupture significantly. Locations that have previously experienced "superquakes" are shown in yellow. Locations that researchers are starting to think could potentially experience magnitude-9 quakes are shown in red. Kathleen Cantner, AGI

A number of recent big earthquakes around the world have humbled many earthquake researchers. The March 2011 magnitude-9 superquake off Tohoku, Japan, and the December 2004 magnitude-9-plus temblor off Sumatra were both far larger than what scientists expected those fault systems to produce. Based on these quakes, and on recent research that contradicts long-held paradigms, it is becoming clear that the types and sizes of large earthquakes that a given fault system is capable of producing remain poorly known for most major fault systems.

Voices: Judged unfairly in L'Aquila - roles and responsibilities should have been considered

Fri, 26 Oct 2012 13:39:27 -0400

A goverment building in L'Aquila, Italy, damaged by the April 2009 earthquake. TheWiz83, Creative Commons Attribution-ShareAlike 3.0 Unported

Earlier this week, an Italian judge summarily convicted seven participants in a meeting of the Italian Serious Risks Commission who evaluated the hazard posed by the L’Aquila earthquake swarm before the magnitude-6.3 earthquake on April 6, 2009, for the same offense and to the same penalty: six years in prison. Much has been written about this court decision, but the very different roles played by the seven defendants and their different expertise have not been discussed. Is there no difference among the roles of the “L’Aquila Seven” in the communication disaster?

Hazardous Living: Italian seismologists tragically convicted of manslaughter

Mon, 22 Oct 2012 14:34:09 -0400

Today, six seismologists and one government official were convicted of manslaughter and sentenced to six years in prison. The seismologists and official had been on trial for not adequately warning the public about the danger of a potential earthquake prior to the L'Aquila earthquake in April 2009 that killed 309 people. This ruling makes the earthquake and the aftermath a double tragedy. It was tragic enough that people lost their lives as a result of the natural disaster. Now the court has compounded the tragedy. What it will mean for seismology and hazards mitigation everywhere remains to be seen — but the implications are troubling.

Blame it on the rain: The proposed links between severe storms and earthquakes

Tue, 16 Oct 2012 13:12:13 -0400

Typhoon Morakot passes over Taiwan on Aug. 7, 2009. It was followed by two large earthquakes, one later in 2009 and one in 2010. NASA image by Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center

Researchers have correlated the timing of slight ground motions in the Himalayas using GPS measurements, including from this GPS station near Simikot in northwestern Nepal, to cyclic variations in seismicity beneath the mountains and the annual monsoon. Thomas Ader

An aerial view of Haiti's capital, Port-au-Prince, about two months after a magnitude-7 earthquake struck nearby. A landslide is evident among crowded hillside houses and buildings. U.S. Navy photo by Senior Chief Mass Communication Specialist Spike Call

A landslide near Haiti's southern coast erodes tremendous amounts of sediment from the mountains, a process that can change the stress loads on faults. U.S. Geological Survey

The U.S. Geological Survey’s website states it in no uncertain terms: “There is no such thing as ’earthquake weather.'”

Risky business: Modeling catastrophes

Thu, 27 Sep 2012 11:05:23 -0400

On Aug. 24, 1992, Hurricane Andrew (shown here in a time-lapse image) made landfall in Florida as a major storm. The cost of storm-related damages was predicted to be about $6 billion based on traditional actuarial models, versus $13 billion based on AIR's catastrophe models. The actual cost of damages was about $16 billion. NASA GSFC

In 2011, insured losses from natural disasters in the United States totaled nearly $36 billion, with most of the losses coming from severe thunderstorm damage. In Alabama, tornadoes left a trail of destruction. AIR Worldwide

Hurricane Katrina, which made landfall on Aug. 26, 2005, remains the most expensive catastrophe ever in terms of insured losses, with $46 billion in insured losses. NOAA

The magnitude-9.0 earthquake and subsequent tsunami in Japan on March 11, 2011, awakened the insurance industry to the potential costs of large tsunamis. The industry is now working to include tsunamis in earthquake cat models. Copyright Katherina Mueller, IFRC

Natural hazards — earthquakes, tropical cyclones and thunderstorms, for example — occur with considerable frequency around the world. Fortunately, most events are either not intense enough or too remote to cause damage. But the probability that a given natural hazard could become a natural disaster is higher today than at any previous point in history.

On the web: Shake, rattle and roll: What does an earthquake sound like?

Mon, 23 Jul 2012 08:11:54 -0400

Using a new technique, researchers have boosted seismic waves (top) from the 2011 Tohoku earthquake to frequencies (bottom) within the audible range for humans. Georgia Institute of Technology

The sounds we associate with earthquakes tend to be those induced aboveground. Low-pitched rumbles, rattling windows and car alarms might be heard during small temblors, while more terrifying sounds like the crumbling of concrete and the cacophony of people trying to reach safety sometimes accompany large earthquakes. But what does an earthquake itself sound like, as rock grinds against rock in a rupturing fault and large amounts of energy are released? Thanks to some recent efforts, we may be starting to get an idea.

2012: The end of the world or just another year of living in harm's way?

Fri, 20 Jul 2012 11:58:39 -0400

The 1.2-kilometer-diameter Meteor Crater in Arizona was formed by a roughly 50-meter-diameter impactor about 50,000 years ago. ©Michael Collier, ESW Image Bank

A pair of curving erupting prominences on the sun on June 28, 2000. Prominences are huge clouds of relatively cool dense plasma suspended in the sun's hot, thin corona. At times, they can erupt, escaping the sun's atmosphere. SOHO (ESA & NASA)

Geysers and thermal waters in Yellowstone reveal the area's seething magma chamber beneath. Brenna Tobler

©Callan Bentley

We live on a knife-edge, separated from an ocean of super-heated rock by a wafer-thin and perpetually rupturing crust, swinging our way through a cosmic minefield of lethal debris around a nuclear furnace prone to tantrums. For doomsayers, the end of the Mayan long-count calendar, set against such a backdrop, is a gift. Though Mayan culture never spoke of a cataclysm, Dec. 21, 2012 — the purported last day of a 5,125-year cycle in the Mesoamerican calendar — has been added to an endless list of days when the world has been predicted to end.

Voices: Italian quakes and deaths point to industrial facilities as death traps

Wed, 06 Jun 2012 13:26:25 -0400

This industrial facility near Sant'Agostino, Italy, collapsed in the May 20 earthquake in Emilia-Romagna, killing two people. The plant was only built two years ago. Max Wyss

Although the old brick barn did collapse during the May 20 earthquake, this abandoned brick farmhouse — within view of the industrial facility near Sant'Agostino that collapsed — is still standing. Max Wyss

A firefighter escorts a resident through a cordoned-off section of Finale Emilia so she can retrieve some personal items from her apartment, which has been deemed uninhabitable. Max Wyss

Thousands of residents of the Emilia-Romagna region are living in tents, unable to return to damaged homes while aftershocks continue. Max Wyss

Protesters block the main road through a small town in northern Italy; they are upset with government officials who the protesters say are not doing enough to help repair the damaged belltower in the center of town. With the belltower cordoned off, the center of town is closed. Max Wyss

On May 29, eighteen people died in northern Italy when a magnitude-5.8 earthquake struck near the town of Mirandola. Arguably, these deaths were preventable, and they bring up the questions of how we can prevent such deaths in the future. Building codes are key in protecting people. If the most modern buildings collapse while old ones remain standing, something is wrong.

Better warnings for the consequences of earthquakes: Bringing seismic hazard and risk assessments to policy

Fri, 25 May 2012 16:03:11 -0400

Adobe masonry, used throughout the developing world, often collapses in large earthquakes, including the 2010 quake in Haiti. Walter Mooney, U.S. Geological Survey

Schools tend to be especially vulnerable in earthquakes. A school in Coalinga, Calif., was damaged in a 1983 quake. Earthquake Engineering Research Institute, courtesy of NOAA National Geophysical Data Center

Much of Lima, Peru, was devastated in a 1974 earthquake. Some of the city has been rebuilt with earthquakes in mind, but even today if a large temblor were to strike the city, many buildings would likely collapse. U.S. Geological Survey

During the last decade, earthquakes have taken a heavy toll on lives, shocking the world. Two exceptionally large earthquakes off the coasts of Sumatra, Indonesia (December 2004), and Honshu, Japan (March 2011), generated tsunamis that swept more than 250,000 people to their deaths in total. In October 2005, a magnitude-7.6 earthquake devastated Pakistani Kashmir, collapsing buildings and triggering landslides that buried about 87,000 people. About the same number of people were killed in Wenchuan, China, in 2008, when the region was hit by a magnitude-8.0 earthquake. The number of fatalities is poorly known in Haiti from the 2010 magnitude-7.0 event near the capital Port au Prince, but it is suspected of killing 100,000 people and destroying nearly 300,000 buildings, including the national palace.

Sumatran strike-slip earthquakes challenge seismologists

Wed, 09 May 2012 14:35:04 -0400

Map showing the location of two large strike-slip earthquakes (red stars) off the west coast of Sumatra, Indonesia on April 11, 2012. Aftershocks (orange circles) of the strike-slip earthquakes are also indicated, as are prominent tectonic features including the Sunda megathrust fault (pink) and a series of north-south fractures (black) in the vicinity of the earthquakes. courtesy of Earth Observatory of Singapore

Events may shed light on regional tectonics, alter stress on nearby megathrust

Following the magnitude-8.6 earthquake that struck off the coast of Sumatra, Indonesia on April 11, chaos reigned in Banda Aceh, a provincial capital near Sumatra’s northern tip as residents scrambled to evacuate to higher ground ahead of a potential tsunami. Unlike in December 2004 when a deadly tsunami — triggered by the magnitude-9.1 Sumatra-Andaman earthquake — swept over the Sumatran coastline, though, no significant tsunamis made landfall on April 11 and only a handful of earthquake-related fatalities were reported.

Managing the seismic risk posed by wastewater disposal

Tue, 17 Apr 2012 13:34:06 -0400

Shale gas and tight oil are produced in the Bakken Formation in North Dakota. Statoil

From an earthquake perspective, 2011 was a remarkable year. While the devastation accompanying the magnitude-9.0 Tohoku earthquake that occurred off the coast of Japan on March 11 still captures attention worldwide, the relatively stable interior of the U.S. was struck by a somewhat surprising number of small-to-moderate earthquakes that were widely felt. Most of these were natural events, the types of earthquakes that occur from time to time in all intraplate regions. For example, the magnitude 5.8 that occurred in central Virginia on Aug. 23 was felt throughout the northeast, damaged the Washington Monument, and caused the temporary shutdown of a nuclear power plant. This earthquake occurred in the Central Virginia Seismic Zone, an area known to produce relatively frequent small earthquakes.

Blogging On EARTH: Wisconsin's microquake mystery

Wed, 11 Apr 2012 17:41:41 -0400

Downtown Clintonville, Wis.©Royalbroil, Creative Commons Attribution-ShareAlike 3.0 Unported

An EarthScope seismometer similar to those installed in Wisconsin that were used to identify a March 20, 2012 magnitude-1.5 microquake near Clintonville. earthscope.org

Tim Oleson is a staff writer at EARTH. photo courtesy of Dave Clark

On the list of earthquake-prone states, Wisconsin does not rank highly. The largest known earthquake in the state (or at least the suspected largest quake given that its magnitude is not well established) occurred somewhere south of Milwaukee on May 6, 1947, with an intensity estimated as high as “V” (or 5) on the Modified Mercalli intensity scale — which is distinct from the moment magnitude scale customarily used to indicate earthquake severity (moment magnitude is often used interchangeably with the Richter Scale, although the two are different and the latter is no longer conventionally used by seismologists) — meaning it shook windows and caused minor damage in nearby areas.

Blogging on EARTH: Panelists weigh in on tsunami preparedness policy

Fri, 23 Mar 2012 16:54:40 -0400

Many low-lying coastal communities in Alaska, California, Hawaii, Oregon, Washington and Puerto Rico have tsunami warning signs and evacuation plans in place. NOAA

DART buoy locations around the world. DART buoys help track tsunamis in real time. NOAA National Data Buoy Center

Abby Seadler is the member society services manager for the American Geosciences Institute and writes about about the government and policy developments for EARTH. Abby Seadler

“It is not a question of whether it will happen, but when it will happen,” said John Schelling, addressing the room at a Congressional Hazards Caucus briefing last week. The briefing, entitled Tsunami Preparedness: Understanding our Nation’s Risk and Response, brought together Schelling, who is the Earthquake and Tsunami Program Director for the Washington State Emergency Management Division, Eddie Bernard, scientist emeritus at NOAA’s Pacific Marine Environmental Laboratory, and John Orcutt, a geophysicist at the Scripps Institution of Oceanography to put forward one question: Is the U.S. tsunami-ready?

Voices: From Haiti to Japan: A tale of two disaster recoveries

Mon, 05 Mar 2012 15:22:23 -0500

A year ago this month, a devastating earthquake and tsunami struck northern Japan. Two years and two months earlier, on Jan. 12, 2010, a much smaller earthquake devastated Haiti. Both earthquakes occurred on a weekday and in the afternoon, but there is very little else that is similar about these two events or how the countries have recovered. Both offer reminders about the uncertainties of the effects of disasters.

Crystal Ball EARTH: Natural Hazards: Reducing society's risks

Fri, 20 Jan 2012 03:51:09 -0500

Many of the world's largest cities, such as Caracas, Venezuela, are hotspots of extreme poverty and most vulnerable to catastrophes following natural hazards. Abby Baca, RMS

U.S. Geological Survey seismologist Lucy Jones and her son, Niels Hauksson, watch the Station Fire near their home in La Cañada Flintridge, Calif. Egill Hauksson

The Station Fire in California burned dangerously close to communications towers and the Mount Wilson Observatory. Todd Hoefen, USGS

More than 65,000 people were left temporarily homeless by the magnitude-6.3 earthquake that struck L'Aquila, Italy, in April. Walter Mooney, USGS

The L'Aquila earthquake crumpled both medieval and modern infrastructure. Walter Mooney, USGS

The global financial disaster of 2009 has many parallels with catastrophic natural hazards. It struck pretty much without warning, its impact was greatly exacerbated by an incredibly complex system of cascading consequences, and finally, mechanisms supposedly in place to mitigate the worse impacts (regulations, in the case of the financial system) failed. There was awareness that such a meltdown could theoretically occur, but it was considered such a low-probability event that it was evidently not worth planning for.

Voices: Geologists on the wrong side of the law

Fri, 20 Jan 2012 03:51:09 -0500

Many of L'Aquila's buildings were reduced to rubble during the April 6 earthquake. INGV

We live in a litigious society. Engineering and environmental geologists are no strangers to the legal system. They frequently deal with issues relating to geologic hazards such as active faults and unstable ground, the release of contaminants into the environment and numerous other circumstances. But for the most part, geoscientists tend to avoid legal battles. Is that changing?

Voices: Italian seismologists: What should they have said?

Fri, 20 Jan 2012 03:51:09 -0500

Many of L'Aquila's buildings were reduced to rubble during the April 6 earthquake. INGV

In Italy, seismologists who failed to predict the L’Aquila earthquake in 2009 could face manslaughter charges. On March 31, 2009, the Major Risks Committee — composed of six seismologists — told the rest of the Civil Protection Department (pdf) and other officials that there was “no reason to suppose a sequence of small earthquakes could be the prelude to a strong event” and that “a major earthquake in the area is unlikely but can’t be ruled out.” In other words, they did not recognize as precursory the sequence of earthquakes in the months that preceded the fatal event of April 6.

Voices: Should science dictate whether to rebuild after a natural disaster?

Fri, 20 Jan 2012 03:51:09 -0500

Four days after a magnitude-7.0 earthquake caused severe damage on Jan. 12, 2010, Haitian citizens remain in the street afraid or unable to return to their homes. U.S. Navy photo by Mass Communication Specialist 2nd Class Candice Villarreal

A Haitian man watches rubble being removed from a collapsed church in Baie De Grand Grove, Haiti. U.S. Navy photo by Mass Communication Specialist 1st Class Monique Hilley

Move Port-au-Prince? Maybe. San Francisco and New Orleans? Never.

It is common for scientists to call for the relocation of a city to a safer location after it is struck by an earthquake or hurricane. After all, when many cities were built, the nature of the hazard they faced was either unknown or very poorly understood. This is true whether we’re talking about San Francisco, Calif., New Orleans, La., or Port-au-Prince, Haiti. Now that we know the hazards, is it time to relocate a city in a dangerous locale? Port-au-Prince? Yes. San Francisco and New Orleans? No.

Voices: The confounding economics of natural disasters

Fri, 20 Jan 2012 03:51:09 -0500

In the hours (not days) after the enormous earthquake hit Japan on March 11, before it was even known that the Fukushima power plant had been badly disabled and well before the scope of the mortality and damage had been assessed, the Japanese yen rapidly appreciated in value. The G7 nations moved to quickly stabilize the yen — not to prevent it from falling, but to prevent it from further appreciating.

Voices: What happened at Fukushima?

Fri, 20 Jan 2012 03:51:09 -0500

The Fukushima Daiichi power plant located in the port town of Okuma in the Fukushima Prefecture, northeast Japan, has six boiling-water-type nuclear reactors supplied by General Electric (units 1, 2 and 3), Toshiba (units 3 and 5) and Hitachi (unit 4) for the Tokyo Electric Power Company (TEPCO) that runs the power station. The power plant was constructed by Kajima Corportation from 1967 to 1973, and the reactors started operating from 1971 (unit 1) to 1979 (unit 6) and had a combined power production capacity of 4.7 gigawatts — about 10 percent of Japan’s nuclear power, thus being one of the largest commercial nuclear plants in the world. What happened following the earthquakes and tsunami in March 2011 at Fukushima was not a single but a series of nuclear accidents.

A history of "Big Ones"

Thu, 05 Jan 2012 06:41:58 -0500

The last time Chile experienced an earthquake larger than magnitude 8.8 was on May 22, 1960, when a magnitude-9.5 earthquake rocked the South American nation, killing 1,655 people and leaving 2 million people homeless, according to the U.S. Geological Survey. It was the largest earthquake in recorded history. Prior to that, a magnitude-8.5 quake struck central Chile near its border with Argentina on Nov. 11, 1922 — the 13th-largest earthquake on record. The newest earthquake also made the record books: It is tied with an earthquake that hit offshore Ecuador in 1906 as the fifth-largest earthquake.

Asia's hazardous month

Thu, 05 Jan 2012 06:41:58 -0500

A magnitude-7.1 quake (large yellow box) hit Japan on Aug. 9. A magnitude-6.4 quake (orange box) hit on Aug. 10. U.S. Geological Survey

A magnitude-7.6 earthquake hit the Andaman Islands on Aug. 10. U.S. Geological Survey

Satellite image of Typhoon Morakot on Aug. 9. Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC

August is shaping up to be a hazardous month for Asia — from the Andaman Islands in the Indian Ocean to Japan. In just the first half of the month, several earthquakes and two typhoons have struck the region. Here’s an update on these damaging events.

Baja quake sheds light on liquefaction

Thu, 05 Jan 2012 06:41:58 -0500

Liquefaction in the Marine District in San Francisco, Calif., caused damage during the October 1989 Loma Prieta earthquake. G. Plafker, U.S. Geological Survey

Data collected by a unique array of instruments located near the epicenter of the magnitude-7.2 earthquake that struck Baja California April 4 are providing scientists with new insight into the phenomenon of liquefaction, a potentially dangerous side effect of major earthquakes.

Benchmarks: August 17, 1959: Hebgen Lake earthquake and landslide

Thu, 05 Jan 2012 06:41:58 -0500

Disrupted ground and trees of a landslide caused by the Hebgen Lake earthquake. U.S. Geological Survey Photographic Library

The Madison River landslide rode across the valley at speeds of up to 160 kilometers per hour and up the opposite valley wall. The leading edge, shown here, is the white ridge of dolomite boulders. U.S. Geological Survey Photographic Library

A large dolomite boulder on the east side of the Madison River landslide, with Earthquake Lake in the background. U.S. Geological Survey Photographic Library

A fault scarp near Red Canyon Creek in Montana shows a 5.7-meter displacement from the earthquake. U.S. Geological Survey Photographic Library

Highway 287, near Hebgen Lake, was fractured in the earthquake. U.S. Geological Survey Photographic Library

A barn collapsed by the fault scarp extending from the foreground through the barn and across the stream. U.S. Geological Survey Photographic Library

You’re camping in Montana, doing some fly fishing on the Madison River. You’ve had a full day of beautiful Big Sky country weather, and had fresh trout for dinner. In your campsite at the Rock Creek Campground, you go to bed satisfied and happy. It’s a nice enough evening that you sleep out in the open, to better appreciate the stars. The waters of the Madison gurgle by, gently lulling you to sleep while Orion shines above.

Benchmarks: December 16, 1811-February 7, 1812: The New Madrid earthquakes strike the Heartland

Thu, 05 Jan 2012 06:41:58 -0500

Central U.S. Earthquake Consortium (CUSEC) Executive Director Jim Wilkinson moderates a panel discussion during the 18th annual 'Earthquakes Mean Business' seminar on Feb. 11, 2011. Alisa Nave, CUSEC

Fissures that formed during the 1811-1812 New Madrid earthquakes can be seen in this 1904 picture from Mississippi County, Mo. Fuller, M.L., U.S. Geological Survey Photographic Library

Seismic risk across the United States as estimated by the U.S. Geological Survey in 2008. Colors show the levels of estimated horizontal shaking. U.S. Geological Survey

Students demonstrate how to protect themselves during an earthquake in this 'Drop, Cover and Hold On' drill. Alisa Nave, CUSEC

This winter marks the bicentennial of a series of powerful intraplate earthquakes that occurred in the central United States over a two-month period beginning on Dec. 16, 1811. Named for New Madrid, one of the settlements on the Mississippi River, these tremors were among the largest historic earthquakes to occur east of the Rocky Mountains.

Blogging on EARTH: AGU: Japan tsunami actually made population more vulnerable?

Thu, 05 Jan 2012 06:41:58 -0500

Megan Sever is managing editor of EARTH and writes the Hazardous Living blog. Jim Sever

Usually, when a major natural disaster strikes, a population becomes more alert and aware. People know what warning signs to watch for; they know what to do should such an event occur again. They increase their chances of staying alive. For example, intergenerational knowledge of tsunamis passed down by island tribes around the Indian Ocean is credited with saving lives during the 2004 Indian Ocean tsunami.

Blogging on EARTH: FEMA's plans for New Madrid

Thu, 05 Jan 2012 06:41:58 -0500

This year is the 200th anniversary of the New Madrid quakes, the series of magnitude-7 to -8 earthquakes that rocked parts of Missouri and Arkansas in the winter of 1811-1812. But even 200 years later, the quakes continue to shake things up. And the Federal Emergency Management Agency (FEMA) is taking precautions — or maybe not.

Blogging on EARTH: Previously unknown fault responsible for Haiti quake

Thu, 05 Jan 2012 06:41:58 -0500

On Jan. 12, a magnitude-7.0 earthquake struck just 15 kilometers from Haiti's capital Port-au-Prince, followed by a multitude of large and small aftershocks. The larger the circle, the larger the quake. Researchers now think the quake may have occurred on a different fault than they initially thought. NASA EARTH Observatory image by Jesse Allen

Meg Marquardt, pictured in Muir Woods in California, is an intern at EARTH. Meg Marquardt

When a magnitude-7.0 earthquake ripped through Haiti on Jan. 12, it was not entirely unexpected. Journal articles had been published warning that the Enriquillo-Plantain Garden Fault, which bisects Haiti, running east-west across the southern half of the country, was overdue for a large disruption. So when disaster struck, scientists swarmed Haiti searching for the epicenter along the famed fault.

Californians prepare for the Big One

Thu, 05 Jan 2012 06:41:58 -0500

At 10 a.m. local time Thursday, a massive magnitude-7.8 earthquake struck Los Angeles. But don’t worry — it was only a drill.

During the Great Southern California ShakeOut Drill, more than 10 million people, ranging from businessmen to schoolchildren, will be exposed to extreme shaking. More than 5 million people will “drop, cover and hold on.” Meanwhile, fire and rescue, together with 300 scientists and engineers, will work to save the city. At least 600,000 buildings will have some damage — much of it from the fires that will rage after the shaking stops — and there will be at least $200 billion in damage. Electricity will be out in some areas for days, and water could be out for as long as six months. And about 1,800 people will be “killed” and 50,000 “injured.”

Cantabrians keep humor in the hardship

Thu, 05 Jan 2012 06:41:58 -0500

Even though the inhabitants of Christchurch (Cantabrians) have had a nonstop year of hardships, they have kept their humor. A local named Bruce Raines started a “You know you are from Christchurch when…” Facebook page and solicited comments, from which he then published a book.

Chile quake/tsunami news coverage: The bad and the good

Thu, 05 Jan 2012 06:41:58 -0500

Blogging on EARTH

As you would expect, there's been tons of coverage of the earthquake off the coast of Chile and the resulting tsunami in the mainstream media. And some of it has been notoriously poor.

In addition to Rick Sanchez of CNN, who took serious and well-deserved heat (and not just from Comedy Central's the Daily Show) for his extremely shouty "nine meters is what now in English?" schtick, a number of geoblogs, including geotripper and Magma Cum Laude, have pointed out the extreme annoyingness of less flashy but still misleading stories like this and this, which imply that NOAA's Pacific Tsunami Warning Center should hang its head in shame for issuing a tsunami warning for Hawaii, since the waves that did arrive were much smaller than they could have been.

Chile's quake larger but less destructive than Haiti's

Thu, 05 Jan 2012 06:41:58 -0500

Cities where citizens reported shaking from the Chile earthquake that struck Feb. 27. Blue indicates weak shaking and red indicates strong shaking. Circle size correlates to city size. U.S. Geological Survey

A USGS ShakeMap of the earthquake in Chile. Blue indicates weak shaking and red indicates strong shaking. U.S. Geological Survey

On Feb. 27, at 3:34 a.m. local time, a magnitude-8.8 earthquake struck offshore Maule, Chile, 325 kilometers southwest of the capital, Santiago. The quake released 500 times more energy than the magnitude-7.0 earthquake that hit Haiti on Jan. 12, according to the U.S. Geological Survey (USGS) — yet the smaller quake produced more extensive damage: The Haitian quake killed more than 200,000 people and left more than 1.2 million people homeless, whereas the Chilean quake killed at least 711 people and displaced 2 million people, according to the New York Times.

China quake kills at least 400

Thu, 05 Jan 2012 06:41:58 -0500

A magnitude-6.9 earthquake struck the western Chinese province of Qinghai early this morning, killing hundreds. U.S. Geological Survey, National Earthquake Information Center

Update:

In 2008, it was the Longmen Shan Fault, a 250-kilometer long thrust fault that divides the 6,500-meter-high Tibetan Plateau from the lower Sichuan basin, which ruptured. However, today's series of quakes occurred several hundred kilometers to the northwest, in the eastern Tibetan Plateau, and were the result of strike-slip faulting, according to USGS.

Closing Istanbul's seismic gap

Thu, 05 Jan 2012 06:41:58 -0500

The North Anatolian Fault breaks into a complicated network of fault branches under the Marmara Sea, where it passes just 20 kilometers south of Istanbul, Turkey's largest city. Tobias Hergert

Since 1939, a progression of deadly earthquakes has been marching westward across Turkey’s North Anatolian Fault, stalking the mega-city Istanbul. Just over a decade ago, a magnitude-7.4 quake struck near Izmit, 100 kilometers east of Istanbul, killing 18,000 people. All signs point to Istanbul as the next likely target. But a new study suggests Turkey’s largest city may be struck by a series of moderate earthquakes, rather than one big event.

Creeping faults warn of impending earthquakes?

Thu, 05 Jan 2012 06:41:58 -0500

San Andreas Fault U.S. Geological Survey (USGS): photographer Robert E. Wallace, USGS.

Researchers drilled the San Andreas Fault and extracted core samples that are now being studied. John I. Garver, National Science Foundation

Studying the San Andreas Fault, Fenglin Niu and colleagues recently found a way to help determine that an earthquake is coming. Fenglin Niu

Earthquakes strike out of nowhere — one minute everything is perfectly calm, and the next minute, the ground shakes violently and buildings crumple. However, many seemingly sudden seismic events are actually preceded by a multitude of creeping changes underground. Detecting and interpreting these changes would help forecast earthquakes, but that detection has proven difficult, partly because scientists don’t yet fully understand the complex chain of events that precipitates a quake. Now a team of researchers may have discovered some hidden clues that may help them identify impending quakes.

Don't forget about the Christchurch earthquake: Lessons learned from disaster

Thu, 05 Jan 2012 06:41:58 -0500

The Oxford Terrace Baptist Church was damaged in the Christchurch earthquake. Schwede66, Creative Commons Attribution-ShareAlike 3.0 Unported

In the aftermath of the devastating magnitude-9.0 earthquake and tsunami that struck the Tohoku region of Japan on March 11, attention quickly turned away from a much smaller, but also highly destructive earthquake that struck the city of Christchurch, New Zealand, just a few weeks earlier, on Feb. 22. Both events are stark reminders of human vulnerability to natural disasters and provide a harsh reality check: Even technologically advanced countries with modern building codes are not immune from earthquake disasters. The Christchurch earthquake carried an additional message: Urban devastation can be triggered even by moderate-sized earthquakes.

Earthquake prediction: Gone and back again

Thu, 05 Jan 2012 06:41:58 -0500

A collapsed bridge after the Tangshan, China, earthquake on July 28, 1976, which killed more than 240,000 people. Although Chinese seismologists 'successfully' predicted the Haicheng quake of 1975, they failed to forecast this one. USGS

After the Haicheng quake, a Chinese seismologist produced this map of strange animal behavior (circled areas) and earthquake fractures (dotted lines). Helmut Tributsch and The MIT Press for the English language edition

Luminous dots over Parma, Italy, on August 10, 2007. Five days later, there was a small magnitude-2.9 quake. The dots may be ionized air from shifting faults, proponents of earthquake prediction say. GAZETTA DI PARMA - Italy

The 1990s and early 2000s were hard times for earthquake prediction research. “For 10 years, there was limited funding in the U.S.,” says Dimitar Ouzounov, a research scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md., and professor at Chapman University in Orange, Calif. That changed in 2004, Ouzounov says, after a magnitude-9-plus quake struck off the coast of Sumatra and set off a tsunami, killing more than 225,000 people in 11 countries.

Earthquake rattles eastern Indonesia

Thu, 05 Jan 2012 06:41:58 -0500

A magnitude-7.5 earthquake rumbled across the island of Sulawesi in eastern Indonesia early Monday morning, leaving four people dead and thousands homeless. U.S. Geological Survey Earthquake Hazards Program

A magnitude-7.5 earthquake rocked through Indonesia's island of Sulawesi at about 1 a.m. local time Monday, leaving four people dead and prompting thousands to flee their homes. Following the mainshock, the region also experienced several strong aftershocks, ranging in magnitude from 5.1 to 5.6.

Earthquake rocks central Italy

Thu, 05 Jan 2012 06:41:58 -0500

A magnitude-6.3 earthquake struck central Italy early this morning. U.S. Geological Survey Earthquake Hazards Program

Updated on April 7:

As of April 7, the death toll from the magnitude-6.3 earthquake that struck central Italy on April 6 has risen to more than 200 people. Italian Prime Minister Silvio Berlusconi declared a state of emergency on Monday. On Tuesday, he told reporters that rescue efforts would continue for two more days.

Earthquake rocks Sumatra

Thu, 05 Jan 2012 06:41:58 -0500

A magnitude-7.6 earthquake rocked Sumatra, the westernmost island of Indonesia, on Wednesday. U.S. Geological Survey Earthquake Hazards Program

Updated on Oct. 1:

A second, magnitude-6.6 earthquake struck southern Sumatra, Indonesia, today at about 8:52 a.m. local time; this time, the epicenter was 215 kilometers southeast of Padang, West Sumatra. The death toll from both events has risen to at least 531 people.

Earthquake shakes southern New Zealand

Thu, 05 Jan 2012 06:41:58 -0500

Southern New Zealand experienced a magnitude-7.6 earthquake on July 15, 2009. U.S. Geological Survey Earthquake Hazards Program

A magnitude-7.6 earthquake rattled the South Island of New Zealand at 8:22 p.m. local time Wednesday. No serious injuries or damages have been reported.

Earthquakes overwhelm Tajikistan, Solomon Islands

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A quake in Tajikistan in Central Asia left thousands of people homeless, and earthquakes and a tsunami devastated parts of the Solomon Islands in the South Pacific.

A magnitude-5.3 earthquake rocked south-central Tajikistan on Saturday about 7:15 a.m. local time. No deaths were reported, but about 20,000 people were left homeless when their mud-brick homes collapsed, according to the Associated Press . Even though the event was moderate on the scale of earthquakes, such events can cause major damage to highly populated areas with poor construction, says Julie Dutton, a geophysicist with the U.S. Geological Survey’s (USGS) National Earthquake Information Center (NEIC) in Golden, Colo.

Geomedia: Twitter gives heads-up to users and officials about earthquakes

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Twitter stirs up a wide range of reactions — it’s hailed as a vital social networking service by some, despised as the ultimate waste of time by others. But the popular online message board does possess one characteristic that is universally undeniable: speed.

Geomedia: Zombie Science? New Madrid and "Disaster Deferred"

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Stumps of trees in Lake County, Tenn., killed by deposits of sand during the New Madrid earthquakes of 1811-1812. U.S. Geological Survey

During the winter of 1811-1812, three strong earthquakes between magnitude 7 and 8 rocked the New Madrid seismic zone, which runs through parts of eastern Missouri and northeastern Arkansas. The quakes opened deep fissures, destroyed forests and lakes, and produced intense ground shaking that liquefied the soil, turning the land to the consistency of jelly across an area of 10,000 square kilometers. They also became the stuff of legend — legend that has been hard to shake, and has made it difficult to realistically assess the modern hazard in the region, asserts Seth Stein, a seismologist at Northwestern University and the author of a new book, “Disaster Deferred: How New Science is Changing Our View of Earthquake Hazards in the Midwest.”

Guatemalan landslide kills 33

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On February 4, 1976, a magnitude-7.5 earthquake struck near Guatemala City and spawned landslides west of the city. But scientists don't yet know whether an earthquake or some other trigger was responsible for Sunday's landslide, which killed 33 people. U.S. Geological Survey

A landslide in northern Guatemala killed at least 33 people Sunday at about 10:30 a.m. local time. With between 40 and 60 people still missing, rescue attempts have been hampered by continual falling rock and threats of further landslides.

Haiti devastated by major earthquake

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A magnitude-7.0 earthquake struck Haiti at 4:53 p.m. EST on Tuesday, causing widespread damage. The earthquake occurred approximately 15 kilometers southwest of the densely populated capital, Port-au-Prince. Early reports indicate severe devastation. The quake is the largest ever measured in Haiti and yet another of a series of disasters to afflict the poorest country in the Western Hemisphere.

Haitian quake no shock to geologists

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Although the magnitude-7.0 earthquake that shook Haiti on Jan. 12 was a horrible shock for millions of people in and around the Haitian capital of Port-au-Prince, the event came as no surprise to geologists. For years, scientists familiar with the geology of the region had been warning that the island of Hispaniola, which Haiti shares with the Dominican Republic, was overdue for a major quake.

Hazardous Living: Collision forces behind devastating Turkey quake

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The North Anatolian Fault breaks into a complicated network of fault branches under the Marmara Sea, where it passes just 20 kilometers south of Istanbul. The new quake did not occur on the North Anatolian Fault. Tobias Hergert

Megan Sever is managing editor of EARTH and writes the Hazardous Living blog. Jim Sever

By Tuesday evening local time, close to 500 people have been confirmed dead and more than 1,300 injured following a major magnitude-7.2 earthquake that struck eastern Turkey on Sunday at 1:41 p.m. local time. Countless people are still trapped under debris after the shallow quake, only 20 kilometers deep, leveled at least 2,260 buildings in Van, Ercis and other cities and villages, according to news reports. Now, freezing temperatures and the possibility of snow on Wednesday bring new dangers to trapped victims and the thousands of people who are displaced and living in cars, tents and outside. Meanwhile, aftershocks, some as large as magnitude 6.0, have continued to shake the region.

Hazardous Living: Geologists to be charged for not predicting earthquake?

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Megan Sever (pictured at Yellowstone) writes Hazardous Living for EARTH. Megan Sever

News out of Italy suggests that seven researchers who did not predict the L’Aquila earthquake in April 2009 are under formal investigation and may be charged with gross negligent manslaughter.

Hazardous Living: Good reading - is the apocalypse upon us?

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Megan Sever (pictured at Yellowstone) writes Hazardous Living for EARTH. Megan Sever

Earthquakes, volcanoes and blizzards, oh my. Is this year anomalous? Has Mother Nature turned on us and decided to shake up the planet? Are we headed toward an apocalypse? Or is God punishing us for passing health care reform by blowing up a volcano (as a certain Fox commentator suggested), or punishing promiscuous women by sending us earthquakes (as a certain Iranian cleric said)? No.

Hazardous Living: Guatemala and Ecuador under volcanic siege ... and other hazards

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Megan Sever (pictured at Yellowstone) writes Hazardous Living for EARTH. Megan Sever

Guatemala's Pacaya volcano and Ecuador’s Tungurahua vociferously erupted on Thursday, wreaking havoc on villages and cities nearby.

Hazardous Living: Italian seismologists on trial for manslaughter

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Megan Sever is managing editor of EARTH and writes the Hazardous Living blog. Jim Sever

Last June, EARTH reported that seven Italian scientists were under investigation and might be charged with manslaughter for not predicting (and warning the public about) the magnitude-6.3 earthquake that struck L’Aquila, Italy, in April 2009. By last fall, it looked like the charges might be dropped – with the support of many of the world’s seismologists. But this week, a judge decided that the case can move forward and that in September, the scientists will go on trial for manslaughter in the deaths of the 309 people who perished in the earthquake, according to a report in this week’s Nature News. They face up to 12 years in prison if convicted.

Highlights of 2011: New Zealand: After 8,000 aftershocks, when will it stop?

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Many churches were damaged or destroyed in the earthquakes. Many that weren't damaged are allowing other congregations to hold services in their buildings. Andy Miah, Creative Commons Attribution-ShareAlike 2.0 Generic

Many neighborhoods still don't have sewer service, so residents are relying on portable toilets. Ann (Helen) Devereux, Creative Commons Attribution NonCommercial-ShareAlike 2.0 Generic

When the earthquakes struck, they liquefied silt and sand that came pouring out from belowground and covered streets. Andy Miah, Creative Commons Attribution-ShareAlike 2.0 Generic

Fissures opened up in the ground from the earthquakes, especially near riverbanks. Ann (Helen) Devereux, Creative Commons Attribution NonCommercial-ShareAlike 2.0 Generic

Damaged buildings have been marked by one of three tags following the earthquakes: Red means the building is destroyed; yellow means a building needs repairs; green means the building is alright. Wayne Feiden, Creative Commons Attribution-ShareAlike 2.0 Generic

Cleaning up all the sand and silt that was liquefied in the earthquakes has taken months. Andy Miah, Creative Commons Attribution-ShareAlike 2.0 Generic

The untold story of life after a major earthquake in Christchurch, New Zealand

Japan's megaquake and killer tsunami: How did this happen?

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On March 11, 2011, at 2:46 p.m. local time, a magnitude-9.0 earthquake ruptured a 500-kilometer-long fault zone off the northeast coast of Japan. Its epicenter was 130 kilometers off Sendai, Honshu; it occurred at a relatively shallow depth of 32 kilometers. The temblor violently shook northeast Honshu for six minutes, and collapsed its coastline by one meter. The thrusting moved Honshu about 2.4 meters eastward, and the seismic waves on the Pacific Ocean floor set off tsunami waves traveling at the speed of a jet plane (about 700 kilometers per hour). Waves 3 to 38 meters tall pounded Honshu’s coastline, destroying towns and villages and flooding areas up to 10 kilometers inland. Tsunami waves also swept across the Pacific, causing damage or disruptions in Hawaii, California, Oregon, Washington and British Columbia.

Killer quake strikes New Zealand

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A magnitude-6.3 earthquake struck New Zealand Tuesday, causing dozens of deaths in Christchurch. U.S. Geological Survey Earthquake Hazards Program

A magnitude-7.0 earthquake shook New Zealand on Sept. 4, 2010. The force of that quake bent about five kilometers of rail line. Tuesday's quake was an aftershock. Malcolm Teasdale, Kiwirail

A magnitude-6.3 earthquake struck Christchurch, New Zealand, at about 1 p.m. local time Tuesday. The quake killed at least 65 people and buried 100 more in rubble. The U.S. Geological Survey (USGS) reports that the quake was an aftershock of an earthquake that hit the region last September.

Large earthquake rattles Baja California

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The Pacific Plate to the west is sliding past the North American Plate to the east, producing numerous strike-slip faults in the region of Mexico's Baja California, shown here. In red: ridge-transform boundaries; in purple: subduction zones; in green: transform faults. USGS National Earthquake Information Center

A magnitude-7.2 earthquake struck northern Baja California, Mexico, at about 3:40 p.m. local time Sunday, according to the U.S. Geological Survey. At least two people were killed, several hundred were injured and thousands were without power as a result of the quake. Aftershocks as high as magnitude 5.0 have continued to rattle the region today.

Large earthquake rocks Iran oil port

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A powerful magnitude-6.0 earthquake rocked southern Iran this morning at about 3:30 p.m. local time. USGS Earthquake Hazards Program

The epicenter of the quake was about 45 kilometers west of the southern Iranian oil port Bandar Abbas. USGS Earthquake Hazards Program

The earthquake occurred near the tectonic plate boundary between the Arabian and Eurasian plates. USGS Earthquake Hazards Program

Wednesday, Sept. 10, 12:30 p.m. EDT — At 3:30 p.m. local time, a magnitude-6.0 earthquake struck Iran near the southern port city of Bandar Abbas. Tremors from the quake were felt as far away as the United Arab Emirates and Qatar, according to the U.S. Geological Survey.

Mag.-8.9 quake strikes Japan, tsunami heads for Hawaii

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The March 11 earthquake was preceded by a series of large foreshocks, beginning on March 9th with a magnitude-7.2 quake and continuing with a further 3 earthquakes greater than magnitude-6 on the same day. USGS Earthquake Hazards Program

A powerful magnitude-8.9 earthquake struck near the eastern coast of Honshu, Japan, today at 2:46 p.m. local time. The quake sent a tsunami racing across the Pacific Ocean to Hawaii, making landfall just before 3 a.m. local time. The Pacific Tsunami Warning Center has more information.

Moonquake mystery deepens

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Apollo 11, 12, 14, 15 and 16 astronauts left seismometers on the moon that recorded hundreds of moonquakes until the experiments were shut down in 1977. NASA

Between 1969 and 1972, five Apollo missions installed seismic stations at their landing sites on the nearside of the moon. Because the moon was thought to be seismically dead, the instruments were left almost as an afterthought to detect meteor strikes. But from the time the stations were switched on until they were decommissioned in 1977, they recorded hundreds of internally generated moonquakes, some as strong as magnitude 5.5 on the Richter scale.

Natural gas production linked to earthquakes in Texas

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A saltwater disposal well, a part of the natural gas production process, may have been responsible for triggering a series of minor earthquakes in the Dallas-Fort Worth area of Texas in 2008, according to a recent study.

Pacific Northwest earthquake threat heightened?

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At any given time, a massive earthquake could strike the coast of the northwestern United States and southwestern Canada, the site of the Cascadia Subduction Zone. Scientists have long known about the potential earthquake threat to major population centers like Portland, Ore., Seattle, Wash., and Vancouver, British Columbia. But scientists thought that the likely place for such a quake was off the coast. New research, however, extends the region likely to quake farther inland, thus indicating the earthquake threat to the people living in the Pacific Northwest is much higher than scientists realized.

Pakistan quake kills at least 170

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Wednesday's earthquake struck about 60 kilometers northeast of Quetta, in Pakistan's Baluchistan province. USGS Earthquake Hazards Program

USGS Earthquake Hazards Program

A magnitude-6.4 earthquake rocked through southwestern Pakistan just after 4 a.m. local time Wednesday, killing at least 170 people and leaving about 15,000 more homeless. That quake was followed by a second magnitude-6.4 quake at 4:30 p.m. local time.

Powerful earthquake strikes Samoa

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Updated on Sept. 30:

A tsunami spawned by Tuesday's earthquake, which struck in the Pacific Ocean between American Samoa and Samoa, swept across the islands on Tuesday, local authorities reported Wednesday. Authorities in the region are reporting that the death toll from the earthquake and tsunami has risen to at least 111 people, including 22 people in American Samoa, 82 people in Samoa and seven in Tonga, according to a report by CNN.

Report from Ground Zero

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On Sept. 16, 2001, smoke still rose from the ground where the World Trade Center buildings once stood. Gregg Swayze, USGS

Halema'uma'u crater on Kilauea volcano in spring 2008. USGS researchers have assessed the characteristics of volcanic ash from this and other volcanoes. USGS Hawaiian Volcano Observatory

Scanning electron microscope image of an elongated crystal of silica found in Mount St. Helens ash in 2004. Heather Lowers, USGS

USGS researchers characterized the extensive dried mud deposits left behind by the flooding from hurricanes Katrina and Rita in 2005. Courtesy of John Lovelace, USGS

Smoke from wildfires blankets the San Diego area in October 2007. USGS researchers studied ash left behind by these fires and are beginning to analyze ash and smoke carried downwind from wildfires. Greg Mendez, USGS

Microscopic framboidal pyrite was found in mud samples from eastern New Orleans suburbs in the aftermath of the 2005 hurricanes. The pyrite was likely from marsh sediments. Greg Meeker, USGS

NASA satellite image shows the different wildfires burning on Oct. 24, 2007, and the extent of the downwind smoke plumes that enveloped much of the Southern California coast. NASA

USGS geophysicist Ray Kokaly takes field reflectance spectroscopy measurements of ash and soil in Southern California burned areas. Todd Hoefen, USGS

How geoscientists aid in the aftermath of environmental disasters

People around the world remember when they first learned of the attacks on New York City’s World Trade Center towers on Sept. 11, 2001. For me, the memories are vivid — my feelings of shock, horror and sadness were similarly etched on the faces of all the attendees of a mining and the environment workshop in Buenos Aires, Argentina, where I was speaking. At that time, I had no idea that our small research group at the U.S. Geological Survey in Denver, Colo., would soon be called upon to help public officials understand the potential health and environmental implications of the disaster and the ensuing rescue, recovery and cleanup efforts.

Scores dead, injured following Indonesian earthquake

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U.S. Geological Survey Earthquake Hazards Program

A powerful magnitude-7.0 earthquake struck a few kilometers off the coast of West Java, Indonesia, at 2:55 p.m. local time on Wednesday, according to the U.S. Geological Survey. NOAA's Pacific Tsunami Warning Center issued a tsunami warning for the immediate region, but canceled it within an hour when no tsunami was detected.

Swarm of earthquakes rattles Yellowstone

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Yellowstone's Excelsior Geyser, in the Midway & Lower Geyser Basin, erupts in July 2001. Jim Peaco, courtesy of the National Park Service

Yellowstone Falls, Wyoming USGS Photo by David E. Wieprecht

An abnormally high number of earthquakes has shaken up Yellowstone National Park in the past week. Since Friday, a “swarm” of more than 250 low-magnitude, shallow quakes has repeatedly rattled an area under Yellowstone Lake, with the highest-magnitude tremor — a magnitude-3.9 quake — on Saturday. The seismic activity has raised fears that the quakes may foreshadow a larger earthquake, or a volcanic eruption — but scientists say there isn’t yet reason to fear an eruption.

Temblor flattens Turkish towns

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The magnitude-6.0 earthquake hit eastern Turkey on the East Anatolian Fault. U.S. Geological Survey

A magnitude-6.0 earthquake struck eastern Turkey at 4:32 a.m. local time Monday. The quake was centered in Elazig province about 625 kilometers east of Turkey’s capital, Ankara. The earthquake toppled buildings, flattened homes, injured at least 100 people and killed 57, according to the Associated Press.

Thinking outside the rocks in the search for ancient earthquakes

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Ancient amphitheater in Pinara, Turkey, a site known to have been struck by earthquakes. Osmanyaylali, Creative Commons Attribution-ShareAlike 3.0 Unported

This famous Japanese color woodblock entitled "The Great Wave off Kanagawa," by Katsushika Hokusai (1760-1849), depicts a large tsunami wave with Mt. Fuji in the background. Library of Congress

Multiple views of a Roman mausoleum in Pinara, Turkey, show how 3-D laser models are used to test different destructive scenarios like earthquakes and rockfalls. The damage to this structure is most consistent with a large earthquake. Klaus-G. Hinzen

The eyewitness accounts, written in columns from right to left, top to bottom, testify that there was no warning of the tsunami, no shaking to drive villagers to high ground before the wave hit, drowning rice paddies and swamping a castle moat. The entries, written by merchants, peasants and samurai, all clearly mark the time and date: just after midnight on Wednesday, Jan. 27, 1700.

Travels in Geology: Glacial pools to sea caves: A tour of New Zealand's South Island

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The limestone layers of Pancake Rocks with a view of the rugged West Coast near Punakaiki. Laurie J. Schmidt

The sedimentary Moeraki Boulders lie scattered along the Koekohe Beach on New Zealand's Otago Coast. Laurie J. Schmidt

Wharariki Beach's surreal vista of arches and caves. Laurie J. Schmidt

New Zealand has a reputation for extreme adventure — sky diving, jet boating, bungee jumping and even “zorbing,” which sends you rolling down a hill inside a transparent plastic ball. But beyond the adrenaline sports, you’ll find unique geologic features in landscapes ranging from volcanoes and alpine peaks to beaches and rainforests.

Tsunami kills hundreds in Indonesia

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Mentawai region of Indonesia. U.S. Geological Survey, National Earthquake Information Center

U.S. Geological Survey, National Earthquake Information Center

Updated on Oct. 28, 2010:

The death toll has continued to rise from the natural disasters that struck Indonesia Monday and Tuesday. Currently, officials are reporting 343 people dead with 338 still missing from the earthquake and tsunami. Meanwhile, the eruption of Mount Merapi has killed 33 so far; after a brief lull, the eruption began again on Thursday.

US earthquakes actually a powerful Siberian quake

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A powerful earthquake struck Siberia Monday - but U.S. seismic stations interpreted its signals as originating closer to home. USGS Earthquake Hazards Program

A magnitude-7.3 earthquake in Siberia Monday was mistaken by U.S. seismometers as temblors in Idaho and California.

VA quake felt far and wide, here's why

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The magnitude-5.8 earthquake was centered northwest of Richmond, Va., and southwest of Washington, D.C. USGS

A significant earthquake today shook residents in Virginia, but the event could be felt far and wide along the East Coast.

When and why L'Aquila came tumbling down

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Many of L'Aquila's buildings were reduced to rubble during the April 6 earthquake. INGV

The Adria Microplate is sliding beneath the European Plate (jagged red line); the subduction tugs the European Plate eastward, causing faulting that produces earthquakes. AGI

Early on the morning of April 6, 2009, a magnitude-6.3 earthquake rocked the Apennine region of central Italy, killing more than 290 people and leaving at least 30,000 homeless. Some 15,000 buildings were damaged or destroyed in L’Aquila, the largest city in the region. Although strong, the earthquake was not powerful enough to easily account for the high loss of life in a developed country. The devastation has prompted some researchers to investigate Italy’s seismic safety codes for new construction — but the problem may have more to do with retrofitting older buildings.