Volcanoes on EARTH Magazine

LIP split by South Atlantic breakup was sourced from deep

Thu, 15 Mar 2018 15:51:47 -0400

Massive volumes of rock called large igneous provinces (LIPs) have formed many times throughout Earth’s history, fed by some of the planet’s mightiest volcanic events. The volcanic eruptions, sometimes lasting millions of years and pouring hundreds of thousands of cubic kilometers of lava onto the surface, have influenced continental breakups, past climate change and mass extinction events. For everything that’s known about LIPs, however, many questions about them remain, including how far below the surface the erupted magma originate. In a recent study, researchers report that the origins of the Paraná-Etendeka LIP likely lay deep in Earth’s interior.

Mediterranean drawdown may have caused burst of volcanism

Tue, 16 Jan 2018 12:26:29 -0500

The Strait of Gibraltar, the seaway connecting the Atlantic Ocean to the Mediterranean Sea between Africa and Europe, closed roughly 6 million years ago, initiating the Messinian Salinity Crisis. Credit: CC0

Between 5 million and 6 million years ago, during an event known as the Messinian Salinity Crisis (MSC), large amounts of seawater evaporated from the Mediterranean Sea leaving massive salt deposits in the basin. How much the sea surface dropped during the MSC is debated, but in a new study in Nature Geoscience, researchers suggest that a large, kilometer-scale drawdown of the Mediterranean Sea may explain not just the thick salt deposits but also a pulse of magmatic activity around the region that occurred at the same time as the MSC.

Volcanism spiked global temps during past hothouse

Thu, 14 Dec 2017 07:03:29 -0500

Kilometers-thick layers of volcanic rock that formed as the North Atlantic ocean basin opened between Greenland and Norway make for stunning mountain backdrops in eastern Greenland today. Carbon emissions that accompanied this volcanism may have caused the large-scale global warming of the Paleocene-Eocene Thermal Maximum. Credit: Michael Storey, Natural History Museum of Denmark.

Roughly 56 million years ago, global temperatures rose 5 degrees Celsius within a few thousand years in an event called the Paleocene-Eocene Thermal Maximum (PETM). Scientists have often attributed the relatively rapid warming of the PETM — frequently used as an analogue for understanding modern warming trends — to large-scale biogenic methane emissions from seafloor reservoirs. But in a new study, researchers tracking carbon and boron isotopes preserved in the shells of tiny marine creatures called foraminifera, or forams, question the conventional wisdom, instead pointing to a volcanic source for the carbon emitted during the PETM.

Glass shards reveal a fiery history in Ethiopia

Thu, 14 Sep 2017 11:51:18 -0400

Scientists drilled below Lake Ashenge, on the western border of the Afar Triangle, for evidence of past eruptions. Credit: Catherine Martin-Jones.

Chains of volcanoes and a lava lake pepper the landscape of the Afar Triangle in northeastern Ethiopia, where eruptions and earthquakes are byproducts of the rifting that is literally ripping Africa apart, but recent eruptions have been docile. Now, scientists studying ash deposits from the last 40,000 years are showing that dangerous, explosive eruptions present an ongoing hazard, striking the region every 1,000 years on average.

Surprise quake at Mount Fuji triggered by rising gases

Thu, 19 May 2016 21:58:28 -0400

With a peak elevation of 2,335 meters, Mount Fuji is the highest mountain in Japan. Credit: Midori, CC BY 3.0.

On March 15, 2011, four days after the magnitude-9 Tohoku megathrust earthquake and tsunami struck Japan, a magnitude-5.9 earthquake shook the southern flank of Mount Fuji. Seismicity has been rare at the volcano since its last eruption in 1707, leading many researchers to suspect that the Fuji quake — which hit about 300 kilometers southwest of the megaquake — was remotely triggered by the Tohoku event. In a new study, scientists looking at the volcano’s underlying structure and plumbing have offered a potential mechanism for how Tohoku’s shaking could have touched off the Fuji earthquake: through rising gas-rich fluids released from the magma chamber beneath the volcano.

King Oraefajokull

Tue, 29 Mar 2016 20:01:51 -0400

View from Skaftafell National Park toward Öraefajökull Volcano. The toe of the Skaftafellsjökull Glacier and its ice lagoon are to the left. Svínafellsjökull Glacier is to the right. Credit: Tommy Bee.

The Öraefajökull Volcano boasts Iceland’s highest peak — 2,109 meters above sea level — and has the reputation of being Iceland’s largest and most violent volcano. Major eruptions in 1362 and 1727 were among the most explosive in the island’s history, and both were accompanied by catastrophic glacial floods. After the 1362 event, the Icelandic word öraefi, originally meaning “area without a harbor,” was rechristened to mean “wasteland.”

Hekla the heckler

Tue, 29 Mar 2016 19:45:15 -0400

Hekla Volcano overlooking the Thjórsá River. Credit: Hansueli Krapf, CC BY-SA 3.0.

Hekla is one of Iceland’s most active volcanoes, erupting more than 25 times since its first recorded eruption in 1104. The most recent eruptions in 1970, 1980, 1981, 1991 and 2000 have allowed geoscientists to create a detailed eruption profile for the volcano.

Eerily quiet Katla

Tue, 29 Mar 2016 19:38:05 -0400

The largest known jökulhlaups are issued by eruptions of Katla Volcano, which lies under the Mýrdalsjökull Ice Cap. The flow rates of Katla's glacial outburst floods can exceed those of the Amazon River. Credit: Malcom Browne, CC BY-SA 2.0.

Katla Volcano is located near the southern tip of Iceland, under the Mýrdalsjökull Ice Cap. Ashfall deposits found as far away as Norway and Denmark indicate that Katla erupted at least 20 times between A.D. 930 and the last eruption in 1918. Its present dormancy is the longest-known quiet period in the volcano’s history.

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.

Impact or eruptions: Are both to blame in the great end-Cretaceous whodunit?

Thu, 31 Dec 2015 11:02:00 -0500

The mountains of basalt that remain hint at the scale of volcanism that heaped massive amounts of lava onto the Indian subcontinent around the time of the Cretaceous-Paleogene transition. Credit: Blair Schoene.

The Deccan Traps sprawl over more than half a million square kilometers of India. Credit: K. Cantner, AGI.

Few episodes in geologic history are as widely recognized as the Cretaceous-Paleogene, or K-Pg, boundary 66 million years ago. Utter “K-Pg,” “K-T” (for Cretaceous-Tertiary, as it’s still commonly known) or “end-Cretaceous” to any geoscientist and you’re virtually assured of a knowing glance as he or she recalls at least the textbook basics of a large bolide impact and mass extinction that finished off the dinosaurs and gave rise to the Age of Mammals. Mention it to science-interested laymen, meanwhile, and they may conjure images of tyrannosaurs peering over their shoulders in anguish as they flee from streaking meteors.

Modeling 'magma mush' could reveal volcanic histories

Wed, 16 Dec 2015 14:36:38 -0500

Researchers have adapted a computer model originally developed to simulate fuel combustion to study the dyanamics of magma mixing in volcanic magma chambers. In this snapshot, hot mantle material injected into a chamber (orange) mixes with cooler liquid magma (blue) and solid crystals (black) already in the chamber. Credit: George Bergantz/University of Washington

Volcanic eruptions can spew large amounts of molten rock and ash, putting nearby communities as well as aircraft at risk. Gas emissions and earthquakes sometimes offer clues of when an eruption will occur, but the internal workings of volcanoes are largely unobservable. In a recent study, researchers illuminated these internal processes with a computer simulation that models the flow of the part-liquid, part-solid “magma mush” beneath volcanoes.

Opalescent pools shimmer beneath Santorini

Mon, 02 Nov 2015 11:11:00 -0500

Dense carbon dioxide-rich pools on the seafloor near Santorini get their distinctive color from opal particles. The pools may answer questions about deep-sea carbon storage and help scientists monitor the volcano for future eruptions. Credit: Rich Camilli, WHOI.

With its bright blue waters and dramatic cliffside villas, Santorini, Greece, is an idyllic vacation destination, but lurking beneath the Aegean waves lay the remains of one of the most active volcanoes in human history. Because of its eruptive past and proximity to population centers, the Santorini Caldera is closely monitored, but a recent expedition revealed something never before seen there or anywhere else: shimmering opalescent pools of carbon dioxide sequestered on the seafloor.

Campi Flegrei makes its own concrete caprock

Tue, 06 Oct 2015 09:53:58 -0400

Stanford University researchers have discovered natural "concrete" that forms in the Campi Flegrei volcanic complex near Naples, Italy, which explains how, in the 1980s, the caldera withstood the most rapid uplift ever recorded. Credit: Stanford University.

In the 1980s, Tiziana Vanorio was a teenager living in the Italian port city of Pozzuoli west of Naples when the Campi Flegrei volcanic complex that underlies the town and its harbor began to stir. Between 1982 and 1984, the caldera swelled more than 2 meters — the most rapid volcanic uplift ever measured anywhere. The rising seafloor shallowed Pozzuoli’s harbor so that ships could no longer enter. The uplift was followed by a magnitude-4 earthquake and thousands of microquakes that prompted the evacuation of 40,000 residents. Thereafter, the seismicity waned and the residents returned home, but geologists were left with a puzzle: How did the caldera withstand such extreme strain and deformation for so long without rupturing?

Ancient floods degassed Lake Kivu

Wed, 02 Sep 2015 11:27:55 -0400

A turbid sediment plume in Lake Kivu in East Africa following a rainfall event. The discovery of ancient megaturbidites in the lake that had been instigated by floods revealed a new trigger for degassing the "killer lake." Credit: Christopher Scholz.

The deep, cold waters of Lake Kivu — a stratified volcanic lake in the East African Rift Valley on the border of Rwanda and the Democratic Republic of the Congo — hold 300 cubic kilometers of carbon dioxide gas and 60 cubic kilometers of methane, which seep from magmatic sources below the lake. An overturning of the thermally stratified waters could release those deadly gases onto a population of nearly 2 million.

Volcanic lightning turns ash into glass

Fri, 07 Aug 2015 10:30:39 -0400

Within the ash plumes of explosive volcanic eruptions, collisions among countless pyroclastic particles sometimes lead to the buildup of static charges that discharge dramatically as volcanic lightning. In a new study, researchers have found that this lightning can, in turn, melt and fuse ash particles into distinctive glassy grains called spherules. Identifying and studying these spherules could help scientists better understand past and future eruptions, the study’s authors suggest.

Bare Earth Elements: "Volcano of Fire" eruption forces evacuations in Mexico

Mon, 13 Jul 2015 14:12:40 -0400

Although calm in this photo, Colima volcano in Mexico has been erupting violently since Thursday, forcing evacuations of surrounding villages. Credit: Jrobertiko, CC BY-SA 3.0

Mexico’s civil protection agency, along with local officials, issued an emergency declaration Saturday for the area surrounding Colima Volcano, after the eruption that began on Thursday intensified into the weekend. The eruption is said to have sent towering clouds of ash upwards of 4 kilometers into the sky, while lava and pyroclastic flows have spewed down the flanks of the volcano also known as Volcán de Fuego, or Volcano of Fire — one of Mexico’s most active.

Down the Earth With: Clive Oppenheimer

Tue, 07 Apr 2015 11:34:54 -0400

Volcanologist Clive Oppenheimer. Credit: courtesy of Clive Oppenheimer.

North Korea is perhaps the most isolated country in the world, with a people, culture and landscape largely veiled from outside observation, which rarely hosts few Westerners. However, in recent years a smattering of western scientists have visited the country, including volcanologist Clive Oppenheimer from the University of Cambridge in England. In 2011, Oppenheimer was invited by North Korean scientists who were concerned about a sleeping giant of a volcano on the northern border with China that had shown signs of restlessness. A few weeks later, he found himself on the imposing but beautiful mountain, known as Paektu-san to the Koreans (or Changbaishan in China), with a small team trying to unravel the volcano’s past and potential future activity. He has returned to North Korea twice since, and is looking to extend the rare collaboration further.

A front-row seat at a fire-and-ice show

Mon, 09 Mar 2015 12:09:48 -0400

A slow-moving eruption in Russia gave scientists a rare opportunity to safely study interactions between lava and snow in the field. Credit: Benjamin R. Edwards.

Many of the world’s volcanoes are high enough and cold enough to sport seasonal snow, and some even boast year-round glaciers. But what happens when those volcanoes erupt and molten lava hits snow and ice? Observing such extreme interactions of hot and cold is often dangerous in the field, but a slow-moving basaltic eruption in Russia in 2012 provided the right conditions to give scientists a close-up view on one fire-meets-ice display.

Getting there and getting around the Andean Volcanoes

Fri, 06 Mar 2015 11:51:03 -0500

The innkeeper at the base of the mountain shows the skiers how the 2011 eruption of Volcán Puyehue reshaped the local landscape, making the map obsolete. Credit: Karin Kirk.

Loading the horses for the trip to base camp. Credit: Karin Kirk.

The towns of Puerto Montt, Temuco and Osorno make suitable jumping-off points for the region, and all are accessed via a short (and scenic!) flight on LAN Airlines south from Santiago, Chile. The volcano ski season lasts from early September through mid-October.

Andean ski volcanoes

Fri, 06 Mar 2015 11:47:11 -0500

The caldera of Volcán Puyehue is an amazing experience, but it’s not for the uninitiated. Several other Andean volcanoes offer brilliant skiing and genuine adventure in a more straightforward setting. Here are three popular options in the region.

Chaitén's vigorous volcanic history revealed

Fri, 06 Mar 2015 11:22:03 -0500

The town of Chaitén, Chile, was buried under more than a meter of ash during the 2008 eruption of the nearby Chaitén volcano, long thought to be dormant. Credit: Brent Alloway.

When the Chaitén volcano erupted in southern Chile on May 2, 2008, the explosive event took local residents — and geologists — by surprise: Previous studies concluded that the mountain had been quiet for more than 10,000 years. Now, a detailed look at sediments preserved in a nearby lake reveals a much more active history for Chaitén, a finding that may impact the proposed rebuilding of the ash-filled town.

Down to Earth With: The USGS Landslide Response Team

Wed, 04 Mar 2015 12:06:12 -0500

Jonathan Godt on a helicopter survey of a landslide in Central California. Credit: USGS.

Over the last year and a half, the Western U.S. has suffered a rash of devastating landslides. The streak began in September 2013, when heavy rains triggered widespread debris flows across the Colorado Front Range. Then came the tragic landslide that buried Oso, Wash., killing 43 people. Two months later, the West Salt Creek slide, a behemoth rock avalanche in western Colorado, killed three people as it barreled down a 5-kilometer-long path.

Travels in Geology: Skiing into the heart of an Andean Volcano

Mon, 02 Mar 2015 16:36:25 -0500

Stratovolcanoes in Southern Chile offer extreme skiing, otherworldly views and unforgettable adventure. Credit: Karin Kirk.

“OK, everybody,“our guide said. “Just calm down.” His voice had an edge to it, but the words were calming. “I know this is intense. But everyone take a deep breath. We’re OK. We’re almost there.” I obeyed, quieted my mind, and hoped that we were indeed almost there. He continued, with a return to his usual lightheartedness, “Remember, you wanted an adventure, and now you’re getting one.”

Magma pancakes underlie Toba supervolcano

Mon, 02 Feb 2015 13:00:59 -0500

Lake Toba in northern Sumatra was created by an eruption from a supervolcano about 74,000 years ago. Credit: ©dollarphotoclub.com/RCH.

Giant eruptions from so-called supervolcanoes eject tremendous volumes of lava and ash, but details about the source of all that volcanic material have been unclear. Now, a new study has found that magma reservoirs intrude into the crust under volcanoes over millions of years in the form of multiple horizontally oriented chambers stacked on top of each other, like a stack of pancakes.

Down to Earth With: Pat Pringle

Tue, 27 Jan 2015 09:24:18 -0500

Pat Pringle at Henderson Inlet, Puget Sound, where he and colleagues have sampled submerged trees. Credit: Michael Polenz, Washington State Department of Natural Resources.

After finishing a master’s degree in geology at the University of Akron in 1982, Pat Pringle left the relative flatlands of Ohio’s Allegheny Plateau and went west to pursue his passion. More specifically, he went northwest, to the U.S. Geological Survey’s (USGS) Cascades Volcano Observatory, lured by the steaming vents and layered debris flows of the recently awakened giant, Mount St. Helens. He was smitten.

Down to Earth With: Volcanologist Stephen Sparks

Tue, 13 Jan 2015 12:55:15 -0500

From the Caribbean to Iceland to the Andes, volcanologist Stephen Sparks has spent a lifetime studying volcanoes. As a professor of geology at the University of Bristol in England for more than 20 years, Sparks has devoted much of his time to figuring out where the next eruption will occur and how to respond to it. His latest effort is a project that will connect experts and technology in a global network to improve volcanic risk assessment.

Mantle plume alternative explains Australian volcanism

Mon, 05 Jan 2015 13:11:35 -0500

Magma often finds its way to the surface along Earth’s crustal boundaries as tectonic plates crash together, rift apart or grind past each other. Less understood is why volcanoes sometimes emerge far away from plate boundaries. Narrow plumes of buoyant mantle rock rising from hundreds of kilometers deep have long been supposed as the source of intraplate volcanoes, but evidence for plumes is lacking in many areas. Now, in a new study, researchers have reported evidence for an alternative process, known as edge-driven convection, which appears to be driving intraplate volcanism in southeastern Australia.

Down to Earth With: Terry Plank

Thu, 18 Dec 2014 10:29:03 -0500

Terry Plank, a geochemist and volcanologist at Columbia University, is a recipient of a 2012 MacArthur Foundation "genius grant." Credit: Courtesy of the John D. & Catherine T. MacArthur Foundation.

“You’re a genius! Now here’s half a million dollars to use however you please.”

Down to Earth With: James Balog

Wed, 17 Dec 2014 11:37:05 -0500

"Chasing Ice," a 2012 documentary about photographer James Balog (above) and his quest to document Arctic ice retreat, won many awards, including one for cinematography at the Sundance Film Festival. Credit: courtesy of James Balog.

Photographer James Balog is known for his groundbreaking environmental photography that examines intersections of humans and nature. His work has appeared in publications ranging from National Geographic and Smithsonian to Audubon and The New Yorker. He has also authored eight books, including the recently released “Ice: Portraits of Vanishing Glaciers,” and he has been honored with dozens of awards, including the Heinz Award and PhotoMedia’s Person of the Year.

Comment: Preparing for the volcano in your backyard: New Zealand sets an example

Mon, 08 Dec 2014 13:00:12 -0500

A view of Auckland, New Zealand, with Mount Eden in the foreground; at least 10 other volcanoes are also within the field of view of the photo. Credit: Kevin Snowden, ©Auckland Council.

Globally, one in 10 people live within 100 kilometers of a geologically “active” volcano — meaning one that has probably erupted in the last 10,000 years and will almost certainly erupt again. As I write this, homes in Pahoa, Hawaii, are being threatened by lava from Kilauea, and at least one home has been engulfed. The devastation that volcanic eruptions can leave behind, the huge uncertainties in what will happen next, and their often-prolonged timescales test communities’ resilience like few other events. Even the effects of distant volcanoes can be crippling: Volcanic ash can suspend air traffic, disrupt electrical transmission lines, require large areas to be cleaned up, and provide many other headaches.

Travels in Geology: Lentils, lace and lava: France's Massif Central

Mon, 08 Dec 2014 11:12:18 -0500

Canoeing offers impressive views of the limestone walls of the Tarn Gorge in Cévennes National Park in France. Credit: Terri Cook and Lon Abbott.

The Massif Central is a roughly 5,000-square-kilometer highland region in south-central France filled with volcanic necks, scenic gorges and picturesque parks and towns. Credit: Kathleen Cantner, AGI.

Paragliders soar after departing from the Puy de Dôme, the highest point in the northernmost of three chains of volcanoes in the Massif Central. Credit: Terri Cook and Lon Abbott.

Tucked between the Pyrenees and the Alps in south-central France is a little-known highland called the Massif Central. This rugged and secluded region is celebrated for its natural beauty, which is preserved in several large parks that attest to the area’s long and diverse human and geologic history. At the heart of the Massif Central is the picturesque town of Le Puy-en-Velay, known for its green lentils, handcrafted lace and potent Verveine liqueur. There, an arresting trio of volcanic necks capped with historical attractions looms above medieval houses, lace workshops and cobblestone streets where pilgrims have gathered for more than a thousand years to begin their long journey to one of Christendom’s holiest sites.

Link between volcanoes and drought cools geoengineering prospects

Fri, 31 Oct 2014 14:26:02 -0400

Large volcanic eruptions, such as the 1991 eruption of Mount Pinatubo, can cool Earth, but geoengineering attempts to replicate the effects may lead to regional droughts. Credit: U.S. Geological Survey, photograph by Richard P. Hoblitt.

The realization that large volcanic eruptions can trigger climatic cooling has inspired some to call for stratospheric geoengineering projects, which mimic volcanic eruptions, to combat the effects of global warming. But the approach is not without risks. And a new study looking at the effects of volcanic eruptions on monsoon cycles in China over the past 700 years elucidates one: Eruptions can also cause profound drought in some regions. The finding suggests that although artificially induced cooling may have benefits in some places, it could backfire in others.

Travels in Geology: Bali beckons

Fri, 03 Oct 2014 09:14:23 -0400

Bali is the top tourist destination in Indonesia — a vast archipelago of more than 18,000 islands stretching more than 5,000 kilometers between the Indian and Pacific oceans. Credit: ©Shutterstock.com/KKulikov.

In Indonesia — a vast archipelago of more than 18,000 islands stretching more than 5,000 kilometers between the Indian and Pacific oceans — Bali is the top tourist destination. The compact island boasts everything a visitor could want: copious sun, sand and surf, flavorful food and fruity libations, stunning sunsets, and verdant rice paddies tucked beneath misty mountains. It also has a number of geo-attractions, including hot springs and Indonesia’s first global geopark. But it’s the engaging, friendly and colorful Hindu culture — from the elaborate temples and dance performances to the ubiquitous religious offerings — that makes Bali such a vibrant and exotic destination. It was a requisite side trip for our family on a recent sabbatical in Australia.

First building blocks in Oahu found

Wed, 03 Sep 2014 08:05:38 -0400

Oahu is the third-largest and most populated of the Hawaiian Islands. Credit: NASA.

The Hawaiian Islands that jut above the waves are merely the tops of a string of towering volcanoes known as the Hawaiian-Emperor seamount chain. These mountains have formed flow by flow, eruption by eruption, over the past 28 million years as the Pacific Plate moves over a hot spot in the mantle.

Kilauea eruptions could shift from mild to wild

Fri, 29 Aug 2014 11:49:57 -0400

Kilauea is the most active of the five volcanoes that form the Big Island of Hawaii and one of the most continuously active volcanoes in the world. Credit: ©Shutterstock.com/Alexey Kamenskiy.

Hawaii’s Kilauea volcano is famously effusive: Low-viscosity lava oozes out of the main caldera and two active rift zones along the southern shore of the Big Island. But scientists suspect that Kilauea’s eruptions haven’t always been so mild, and a new study is providing further evidence supporting that notion. In the past 2,500 years, at least two cycles of explosive eruptions lasting several centuries each have rocked the island. The switch from effusive back to explosive is likely to occur again, scientists say, but probably not anytime soon.

Santiaguito Volcano's clockwork behavior provides an exceptional laboratory

Fri, 29 Aug 2014 10:53:27 -0400

A large eruption as captured from the so-called "Paradise" campsite between the parent volcano, Santa María, and the Caliente dome. Credit: Benjamin R. Phillips.

Self-portrait of the author on the edge of the nearly 2-kilometer-high scarp of Santa María. Credit: Benjamin R. Phillips.

If Earth breathes, Santiaguito Volcano in the Western Highlands of Guatemala could be its mouth. Roughly every half hour, like volcanic clockwork, Santiaguito’s active Caliente lava dome expands, filling with gas from depressurizing magma below. Then it exhales, often explosively, and deflates. Over the course of a day, you could almost keep time by it.

Infrasound reveals lava lake levels

Thu, 21 Aug 2014 18:58:48 -0400

Only rarely can scientists get a view of the lava lake atop Villarrica volcano. Credit: Greg Waite.

The rises and falls of volcanic lava lakes are not easily tracked, especially when the lakes aren’t visible from crater rims. But recently, researchers found a way to monitor the lava lake at Chile’s Villarrica volcano using complementary methods to keep an eye on a feature they can’t always see.

Benchmarks: August 15, 1984 & August 21, 1986: African killer lakes erupt

Mon, 11 Aug 2014 15:23:07 -0400

In August 1986, a carbon dioxide eruption from Lake Nyos in Cameroon killed more than 1,700 people. This photo was taken in early September 1986 by U.S. Geological Survey scientists studying the disaster. Credit: USGS.

Only three lakes in the world are known to explosively release dissolved gases from their bottom waters. All three are in Africa; two have erupted with deadly consequences.

Volcanic ash feed southern ocean plankton

Fri, 08 Aug 2014 11:54:55 -0400

Technicians aboard the British RRS James Cook retrieve a seawater sampling device in the Southern Ocean. Credit: Gideon Henderson.

Ash plumes from volcanoes in South America and elsewhere may spur large blooms of plankton in otherwise barren parts of the Southern Ocean, but maybe not for the reason scientists have suspected, according to a new study. Such blooms are of interest because they consume atmospheric carbon dioxide, although their overall effect on climate remains far from clear.

New model predicts pumice drift patterns

Fri, 08 Aug 2014 10:45:29 -0400

In July 2012, the Havre volcano in the remote southwestern Pacific erupted, creating a raft of pumice that covered more than 400 square kilometers of ocean. Despite the raft’s massive size, the event went unreported for three weeks, until a passenger aboard a New Zealand-bound plane noticed the floating mass from above.

Living in the shadow of Mauna Loa: A silent summit belies a volcano's forgotten fury

Thu, 07 Aug 2014 10:34:10 -0400

Earth’s largest active volcano is taking a nap. And after 30 years, no one is quite sure when Hawaii’s Mauna Loa will reawaken. Odds are that it will be within the next couple of decades — and that it will be spectacular.

Augustine Volcano's earthquakes and explosive eruption caused by a clogged conduit

Mon, 28 Jul 2014 18:32:36 -0400

Augustine is one of Alaska's most active volcanoes. Credit: Game McGimsey, AVO/USGS.

Located 280 kilometers southwest of Anchorage, Augustine is one of the most active volcanoes in the volcanically active state, erupting every 10 to 20 years. Because of its history of frequent eruptions — five blasts in the past 75 years — and close proximity to Anchorage and other communities in south-central Alaska, Augustine is one of the best-monitored volcanoes in the state. “You can see Augustine’s ash clouds from Anchorage, so people really pay attention to it,” says Helena Buurman, a volcano seismologist at the University of Alaska in Fairbanks and lead author of the new study, published in Geophysical Research Letters.

Shifting winds blow away Taupo's 'Ultraplinian' title

Mon, 23 Jun 2014 16:07:49 -0400

New Zealand's Lake Taupo is all that remains of the volcano that gave rise to one of the world's most explosive volcanic eruptions, but new research may downgrade the infamous blast. Credit: Dougal Townsend, GNS Science, New Zealand.

Today, all that remains of the Taupo Volcano is a lake-filled caldera on New Zealand’s North Island that was blasted out during the Oruanui eruption about 26,500 years ago. The most recent eruption, known as the “1800a” Taupo eruption, is considered to be the largest volcanic event in the past 5,000 years and one of the most explosive eruptions in Earth’s history.

Magma mobilizes quickly beneath Mount Hood

Mon, 09 Jun 2014 13:16:20 -0400

New research looks at the eruptive potential of Mount Hood in Oregon. Credit: Kari Cooper.

The term “magma chamber” might evoke thoughts of a roiling mass beneath a volcano, ready to blow at any moment. But in a recent study in Nature, researchers found that magma beneath Oregon’s Mount Hood spends minimal time in this eruptible state. Instead, magma remobilization and eruption occur within a short time frame.

Resolving a misplaced source of volcanism in the Galapagos

Mon, 07 Apr 2014 14:04:56 -0400

A view of an active volcano on Isabela Island in the Galapagos. Credit: Doug Toomey.

Geological models have long suggested the mantle plume that built the Galápagos islands lies below Fernandina Island. Using a novel combination of seismic techniques, however, scientists have found a mantle anomaly that appears to be the Galápagos plume located 150 kilometers southeast of Fernandina Island. The new findings better explain the ongoing volcanic activity and also shed light on interactions between the mantle and crust, researchers say.

Volcanic lightning generated in a bottle

Wed, 19 Mar 2014 10:10:31 -0400

Lightning was captured in images of the erupting Sakurajima Volcano in southern Japan in January 2013. Credit: Copyright Martin Rietze.

In A.D. 79, during the catastrophic eruption of Mount Vesuvius, Pliny the Younger wrote of a “blaze of lightning” illuminating the ash plume, marking the first recorded observation of volcanic lightning. Nearly 2,000 years later, scientists still know very little about how lightning is generated by volcanic eruptions, in large part because of the danger and difficulty in monitoring the phenomenon in the field. But a new apparatus for generating volcanic lightning in the lab may shed light on the subject.

GPS measurements of ground inflation help forecast ash plumes

Thu, 20 Feb 2014 16:07:31 -0500

When Grimsvötn Volcano in Iceland erupted in May 2011, northern European airspace was closed for seven days and about 900 passenger flights were canceled. Scientists were charged with trying to read the volcano — to tell how high the ash plume would go and to figure out how long the violent eruption would last. Such features are hard to predict, but in a novel study, one research team has found a correlation between the height and composition of the Grimsvötn ash plume and ground deformation before and during the eruption. The findings, the team says, could improve volcanic plume dispersion models, which in turn could help air traffic managers determine when and where it’s safe to fly when volcanoes like Grimsvötn and Eyjafjallajökull suddenly erupt.

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.

Droning on for science

Wed, 12 Jun 2013 14:27:47 -0400

The Sensor Integrated Environmental Remote Research Aircraft (SIERRA) on the tarmac at NASA's Crows Landing Airport in California. Courtesy of Jonathan Glen, USGS

A high-resolution aerial photograph of an alligator near Lake Okeechobee taken from the Nova 2.1 UAV. J. Martin et al., 2012, PLOS ONE

Amid rolling green pastureland dotted with livestock and the occasional cluster of trees, Costa Rica’s imposing Volcán Turrialba rises 600 meters above the surrounding landscape about 40 kilometers east-northeast of San José. On a clear day last March, a light column of volcanic steam rose from Turrialba — as it has steadily for several years — while a twin-propeller airplane made slow passes through the plume and over the mountain’s summit and flank.

Down to Earth With: The Lava Cap Winery

Mon, 15 Apr 2013 08:25:05 -0400

Lava Cap Winery lies in the foothills of the Sierra Nevadas near the site of California's first Gold Rush strike. courtesy of Lava Cap Winery

Volcanic mudflow deposits of the Miocene-aged Mehrten Formation crop out in the vineyard. courtesy of Lava Cap Winery

Geologist David Jones started Lava Cap Winery with his wife Jeanne in the 1980s. courtesy of Lava Cap Winery

Thanks to its location and rich volcanic soils, Lava Cap Winery is able to make 12 different wines, but is best known for its zinfandel. courtesy of Lava Cap Winery

During a long career at the U.S. Geological Survey (USGS) and the University of California at Berkeley, paleontologist David Jones, who died in 2007, made fundamental contributions to understanding the geologic history of western North America, particularly the evolution of California’s puzzling Coast Ranges. One of Jones’ more significant contributions was a paper on the distribution of Buchia, a Mesozoic mollusk, which provided critical age information and helped clarify very complex structural relations in the Coast Ranges. “But Davy was much more than a paleontologist,” says colleague Eli Silver, a geophysicist at the University of California at Santa Cruz who studies continental margin evolution. “He was an outstanding stratigrapher and structural geologist, and a field geologist second to none. He really knew geology inside and out.”

The Syracuse University lava experiments

Fri, 17 Aug 2012 14:53:11 -0400

Pouring basaltic lava at Syracuse University's Comstock Art facility: Sheet-like, ropey pahoehoe flows over dry sand; infrared image of pahoehoe flow experiment with selected temperatures in degrees Celsius.

Pouring Lava

Melting a batch of the ancient basalt takes about four hours, but we hold the lava above its melting point for much longer to ensure that it is completely melted and to remove unwanted volatiles such as water. The lava is then poured at temperatures of 1,100 to 1,350 degrees Celsius, comparable to eruption temperatures of natural lava. We monitor it with a spot calorimeter and a Forward-Looking Infrared (FLIR) camera, the same instrument conventionally used at lava flows in the field.

Do–it–yourself lava flows: Science, art and education in the Syracuse University Lava Project

Fri, 17 Aug 2012 13:56:15 -0400

Picture this: You’re walking across the tree-lined quad of Syracuse University, amid brick and stone buildings, when you happen upon a crowd of people. Crowds on the quad aren’t unusual, but this crowd is unusually diverse — students, professors and even parents with kids. You move a little closer and smell something odd: a blend of sulfur and marshmallows. Then you see it — molten lava pouring down the slope of a parking lot.

Kilauea's Explosive Past - and Future

Wed, 16 May 2012 19:37:43 -0400

Kilauea can produce flowing lava fed by colorful fountains — seen here in December 1969. Don Swanson, U.S. Geological Survey Photographic Library

Even Kilauea's more gentle flows can be quite destructive, such as when lava took out this school in Kapoho in January 1960. U.S. Geological Survey Photographic Library

Lava flows across Chain of Craters Road in Hawaii Volcanoes National Park on May 5, 1973. R.L. Christiansen, U.S. Geological Survey Photographic Library

“Namakeha and some other chiefs in the train of Kamehameha, went with soldiers to Ka’u [on the southern coast of the Big Island of Hawaii], to exterminate Keōua. But Keōua was at Hilo [in the east]. He heard of the invasion of the enemy and hastened to the scene of the action. His path led by the great volcanoe of Kilauea. There they encamped. In the night a terrific eruption took place, throwing out flame, cinders and even heavy stones to a great distance, and accompanied from above with intense lightning and heavy thunder … [O]n the second night and on the third night also there were similar eruptions. On the third day they ventured to proceed on their way, but had not advanced far, before a more terrible and destructive eruption than any before, took place …

Danger in paradise: The hidden hazards of volcano geotourism

Fri, 16 Mar 2012 18:41:52 -0400

Hawaii's Kilauea volcano often flows into the ocean, creating a beautiful but dangerous site. USGS HVO

Warning sign outside the visitor's center at Hawaii Volcanoes National Park. Megan Sever

Sandboarding is a popular tourist activity on Cerro Negro in Nicaragua. NicaPlease

In November 2000, rangers at Hawaii Volcanoes National Park made a gruesome discovery. The bodies of a man and a woman, in an advanced state of decomposition, were found near the site where lava from the Kilauea eruption flows into the sea, sending up plumes of scalding white steam. The area, aptly named the Eruption Site, is littered with chunks of tephra, a glassy volcanic rock, which are formed and ejected violently into the air when the 2,000-degree-Celsius lava is quenched by seawater.

AAG: Eruption of El Salvador's Ilopango explains A.D. 536 cooling

Sat, 25 Feb 2012 13:22:01 -0500

A massive eruption of Ilopango volcano in El Salvador, today a crater lake, may have triggered the global climate cooling of A.D. 536. The only historical eruption at Ilopango took place in 1879-1880, during which a lava dome formed creating the Islas Quemadas in the central part of the lake. NASA Earth Observatory

El Salvador’s Lake Ilopango, near the capital city of San Salvador, is known for boating, diving and the rugged, scenic beauty of its 100 meter-tall cliffs --- the lip of the caldera that holds the lake. However, 1,500 years ago, it may have been the site of one of the most horrific natural disasters in the world. It may also be the long-sought cause of the extreme climate cooling and crop failures of A.D. 535-536, reported Robert A. Dull of the University of Texas at Austin at the Association of American Geographers annual meeting in New York this week.

Comment: Volcanic versus anthropogenic carbon dioxide: The missing science

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

Alaska's Mount Redoubt, during a 1990 eruption. USGS

“Volcanoes add far more carbon dioxide to the oceans and atmosphere than humans.” So says geologist Ian Plimer of the University of Adelaide in his 2009 best seller “Heaven and Earth: Global Warming — the Missing Science.” With this assertion, Plimer brings volcanic carbon dioxide degassing front and center in the climate change debate, reviving and reinforcing this wildly mistaken notion.

Voices: Dead or alive ... or neither? Why a dormant volcano is not a dead one

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

Quite a lot of volcanic activity has been reaching the news lately — Sinabung in northern Sumatra, a possible eruption in the Congo and another Sumatran volcano called Seulawah Agam that may be “waking up” after 170 years of quiet. One thing that’s been mentioned in many of the news reports about these events is that the eruptions were “unexpected” or “surprising” because people had always assumed the volcanoes in question were dormant. But what does dormant really mean? And what does active or extinct mean?

Voices: Volcanoes everywhere ... is there a link?

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

It may seem that there has been an unusual amount of volcanic activity lately, with major eruptions occurring in Iceland, Guatemala and Ecuador. But is it really unusual, and are the eruptions connected?

The short answer to both questions is no.

AGU: Aloha, magma! Geothermal engineers drill into surprising lava

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

Aerial view of channelized lava flow from Pu'u O'o in 1983. Photo is by J.D. Griggs, courtesy of U.S. Geological Survey

The location of Kilauea's Pu'u O'o crater activity in 2001. NASA Landsat

SAN FRANCISCO — While drilling deep into Earth, geothermal engineers struck geological gold, opening a never-before-seen window into a classic geologic process: how basalt magma becomes granite. The find, they announced at the annual meeting of the American Geophysical Union on Tuesday, could amount to the first magma observatory on Earth.

AGU: Mount St. Helens has gone back to sleep

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

Aerial view of Mount St. Helens' crater, as seen from the north on May 30, 2008. Scientists say the eruption that has been ongoing since October 2004 ended early this year. Steve Schilling, USGS

Seismometers recorded a spike in earthquake activity when the volcano first renewed its eruption in October 2004. Seismic activity has since waned. John Clemens, USGS

USGS scientist Michael Poland collects information from a GPS station on the east flank of Mount St. Helens. Many GPS stations have been installed on or around the volcano to measure ground deformation. Dan Dzurisin, USGS

Researchers dropped "spiders" onto Mount St. Helens' growing lava dome to track the eruption in locations too dangerous for humans to go. Dan Dzurisin, USGS

One way researchers gather data on volcanic gas emissions is through devices like this on the helicopter step, which collects data as researchers fly over the volcano. Ken McGee, USGS

The decapitated Mount St. Helens in 1983, three years after the devastating 1980 eruption that killed 57 people. The gigantic debris avalanche that removed the former summit swept through Spirit Lake, spawning a 250-meter tsunami. USGS Cascades Volcano Observatory

SAN FRANCISCO — After more than three and a half years of continuous eruption, Mount St. Helens in Washington quieted earlier this year. Following intense monitoring efforts, the volcano is officially “asleep,” researchers reported Thursday at the annual meeting of the American Geophysical Union.

Alaska's Mt. Redoubt erupts at last

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

Blogging on EARTH

After months of threatening and rumbling, Mount Redoubt finally erupted late Sunday night.

Redoubt began to exhibit increasing unrest last fall, with seismic activity becoming markedly increased in January, and expectations of an imminent eruption were growing. On March 15, researchers detected four hours of continuous volcanic tremor and observed of a brief plume of gas and ash, according to the U.S. Geological Survey's Alaska Volcano Observatory.

Beads of water on the moon

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

Scientists used these small volcanic glass beads to determine that the moon's mantle once held water (and possibly still does). NASA

During the Apollo missions, NASA astronauts shoveled, bagged and sent back to Earth close to 400 kilograms of lunar rocks and soil. But researchers studying these samples never found water. Now, after decades of coming up dry, scientists have found evidence that the moon’s interior once held — and perhaps still holds — water.

Blogging on EARTH linkfest: More on the Iceland eruption

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

Blogging on EARTH: Iceland links and Volcanoes 301

There's a lot of great info out there about the Iceland eruption's geology, if you know where to link.

An invaluable source of information on the geologic evolution of the eruption at Eyjafjallajokull has been the Eruptions blog at Scienceblogs. Geologist Erik Klemetti has a great post up today describing in detail how the volcanism there is now changing, including lava flows from the new crater and a smaller ash plume. He suggests that at least at the moment the volcano is displaying Strombolian activity (see below).

Blogging on EARTH: Second dispatches from EGU

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

EARTH’s Carolyn Gramling is in Vienna, Austria, at the European Geophysical Union meeting this week. Here are a few more sessions that she has found interesting (for more from the meeting, see her first “Dispatches”).

Differentiating natural from human influence on the Sahel

The Sahel, the semi-arid transition zone south of the Sahara Desert, supports about 50 million inhabitants and is particularly vulnerable to changes in precipitation. In 1975, meteorologist Jule Charney of MIT suggested that desertification in the region — the advance of the Sahara into the Sahel — might be due to overgrazing, through a biogeophysical feedback mechanism. Charney suggested that the removal of vegetative cover would increase the albedo over the region, reflecting more radiative energy back into space. That, in turn, would reinforce the sinking circulation of dry air masses in the troposphere; those dry air masses would produce less rainfall, which in turn would foster even less plant growth.

Fire and ice produced Eyjafjalla's explosion

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

Eruption on April 17. NASA image by Jeff Schmaltz, MODIS Rapid Response Team

Eruption of Eyjafjalla volcano on April 1. NASA image by Robert Simmon, using ALI data from the EO-1 team

Ash from the April eruption covered much of Northern Europe. NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team at NASA GSFC

When an Icelandic volcano with a nearly unpronounceable name erupted after 200 years of quiet in March, it was little more than a curiosity. But when it erupted again in April — this time spewing huge clouds of ash as high as 11 kilometers into the stratosphere, quickly choking airways across Europe and costing airlines billions of dollars — it captured the world’s attention. As the ashfall decreased and airlines resumed normal routes this week, the headlines began to fade. But scientists are only beginning to piece together the unusual combination of forces behind Eyjafjalla volcano’s powerfully explosive eruption.

Glaciers, not eruption: False alarm volcano mystery solved

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

When deep, long-period earthquakes started shaking the area around the Katla volcano on the southern tip of Iceland in 2001, officials feared it was a sign of an imminent eruption, as such quakes can be. So they were surprised when nothing happened. A new study identifies the source of the spurious signals: collapsing glaciers around the volcano, not the volcano itself. The finding may help researchers more accurately monitor other glacier-covered volcanoes.

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

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

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

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

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: Iceland afire

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

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

When Iceland’s Eyjafjallajokull volcano began erupting March 20, few people expected it to wind up wreaking havoc on the world’s travel. Yet that’s what it has done, as the eruption has ramped up in the last few days and is now spewing steam and ash several kilometers into the air. The winds over the North Atlantic have blown the ash cloud over Northern Europe, grounding tens of thousands of flights for myriad reasons, not the least of which is that ash can clog jet engines, causing them to fail. Although canceled flights have certainly inconvenienced people, including several of my friends who are stuck in Stockholm and Paris, such inconvenience pales in comparison to the dangers faced by Iceland’s residents.

Hazardous Living: Thirty years after Mount St. Helens exploded

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

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

Thirty years ago today, sometime not long after 8:30 a.m. Pacific time, Mount St. Helens explosively erupted. The shock wave from the eruption washed over Oregon and Washington, shaking the ground up to 400 kilometers away. Two earthquakes followed, at 8:32 and 8:34 a.m. Shortly thereafter, with a tremendous burst, the upper north flank gave way as gas, steam and ash vented outward and sent out an immense landslide of hot rock, mud, water, ash and debris. It was the worst volcanic disaster the United States had seen.

Merapi continues to erupt

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

Indonesia’s Mount Merapi sent another powerful blast of searing ash and rock into the sky again on Wednesday, marking the volcano's most powerful eruptions since it began erupting again on Oct. 26.

The volcano’s periodic eruptions over the last week have so far killed 38 people, mostly due to burns, according to the Associated Press. The volcano's activity Nov. 3 prompted the evacuation of thousands of people living within a 15-kilometer radius around the smoking crater.

Offbeat Betting: Volcano betting gathering steam

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

You never quite know when a given volcano is going to erupt — but you can bet on it. Ireland’s biggest bookmaker, Paddy Power, jetted to fame among geologists in early January, when it announced its latest novelty bet: which of a handful of famous volcanoes around the world would be the next to powerfully erupt.

Pacific Northwest earthquake threat heightened?

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

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.

Report from Ground Zero

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

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.

Scientists assess Redoubt's fury

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

After a series of five explosive eruptions from Sunday night through Monday morning, Alaska's Redoubt volcano quieted for about 15 hours Monday afternoon — long enough for scientists from the U.S. Geological Survey's Alaska Volcano Observatory to travel to the volcano to make observations and repair equipment (including the Redoubt webcam). A sixth explosive eruption followed Monday night at about 7:40 p.m.

Storms brewing over volcanoes

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

Lightning illuminates the night sky over Redoubt Volcano in March 2009. Photo courtesy of geologist and photographer Bretwood Higman

Two hundred years ago, a sea captain was sailing in the Azores, a Portuguese archipelago in the middle of the Atlantic Ocean, when he observed “an immense body of smoke rising from the sea.” As he watched, the smoke, from a volcanic vent offshore of the island of St. Michael’s, began to rotate on the water “like a horizontal wheel,” the captain wrote in his 1811 account of the event. The rotating smoke and ash grew into a dark column and ascended high into the sky, spawning waterspouts and flashes of lightning. “To give you an adequate idea of the scene by description is far beyond my powers,” he wrote.

Swarm of earthquakes rattles Yellowstone

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

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.

The trailblazers

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

Plumlee and his team have worked with USGS colleagues at volcano observatories in Alaska, Cascades and Hawaii to assess potential environmental and health hazards from volcanic ash from eruptions such as the March 2009 Redoubt eruption. Michael Collier, ESW Image Bank

Volcanologists have long been assessing the impacts of volcanic ash and gases on the environment and human health. This effort began in earnest when volcanologists at the U.S. Geological Survey undertook extensive studies of the environmental characteristics of ash from the 1980 Mount St. Helens eruptions. These studies included water leach tests showing that rain falling onto fresh ash can be quite acidic due to the liberation of acidic gas species that condense onto ash particles in the eruption cloud. Studies of other eruptions from around the world have repeatedly demonstrated that fluoride can be leached in sufficient quantities to trigger fluorosis (a bone disease caused by too much fluoride) in livestock or wildlife that drink ash-affected water or eat ash-coated vegetation.

Tracking volcanic ash: Helping airplanes avoid catastrophe

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

Chaitén's eruption sent a cloud of ash wafting over Chile, Argentina and the Atlantic Ocean. NASA image created by Jesse Allen, using EO-1 data provided courtesy of the NASA EO-1 team

Alaska's Redoubt volcano erupted violently in the spring of 2009. Chris Waythomas, Alaska Volcano Observatory, USGS

For more than 9,000 years, Chaitén volcano quietly towered 1,122 meters over southern Chile. The volcano seemed almost asleep: Its wide crater, shaped by layers of ash and pumice from an ancient eruption, held two lakes and a giant dome of obsidian — the same glossy black rock that was used in prehistoric times to shape artifacts found at archaeological sites as far as 400 kilometers away. Almost at the foot of the volcano, just 10 kilometers to the southwest, a small village grew into the town of Chaitén, population 4,200.

Tracking Yellowstone's Activity

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

New technologies track the feverish supervolcano in real time

This story has been modified since it was originally published in EARTH.

Over the past 2.1 million years, Yellowstone volcano has had three explosive super-eruptions. During the most recent super-eruption 640,000 years ago, the supervolcano ejected 2,500 times as much ash and lava as the 1980 Mount St. Helens eruption. If such an eruption were to occur today, it would bury the immediate vicinity in ash flows up to 600 meters deep, and would ultimately spread ash across the western half of North America. Meanwhile, sulfur aerosols and ash particles from the volcano would travel the world, lowering temperatures, devastating agriculture and causing alarming water and air quality issues.

Travels in Geology: Climbing Mount Shasta

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

Footprints leading to the West Face of Mount Shasta. boulab, Creative Commons Attribution-ShareAlike Unported

As we neared the top of the West Face of Mount Shasta, my calf muscles felt like they were pulling apart, stretching to the breaking point. My crampons merely dinted the shimmering snow, leaving dainty bird-like tracks. Roped behind our guides, our group of three climbers switchbacked slowly up the 35-degree-angle slopes. Approaching nearly 4,000 meters in elevation, my lungs grasped for air.

Travels in Geology: Lassen Volcanic National Park: A volcanic wonderland

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

Lassen Peak is the world's largest dacite plug dome. The volcano last erupted in 1921. R. Forrest Hopson

The 6-hectare Bumpass Hell is home to hot springs, mud pots and fumaroles. Rene Rivers, Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic

About 300 years ago, one of the plug domes of Chaos Crags collapsed, creating the Chaos Jumbles rockfall deposit. R. Forrest Hopson

For breathtaking volcanic scenery, few places have the variety found in Lassen Volcanic National Park in the Cascade Range of Northern California. The park boasts five varieties of volcanoes: plug domes, cinder cones, lava cones, shield volcanoes and a stratovolcano called Brokeoff volcano (or Tehama volcano). Bubbling hot springs, boiling mud pots and fumaroles in six geothermal fields in the southern part of the park complete the picture.

Travels in Geology: Taking in Hawaii's Big Island

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

The Big Island of Hawaii, with two snow-topped peaks: Mauna Loa, to the south, and Mauna Kea, to the north. NASA Earth Observatory

For a bit of money, visitors to Hawaii can indulge their touristy impulses with a single night of mai tais and luaus. But take on Hawaii’s geologic hallmarks, and you’ll embark on a low-cost safari that will last you all week.

Tsunami kills hundreds in Indonesia

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

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.

Undersea volcano erupts near Tonga

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

Blogging on EARTH

One of Tonga's submarine volcanoes is awake again, sending spectacular plumes of smoke, ash and steam high into the sky. MSNBC has video here.

A team of Tongan scientists headed out today to investigate the eruption, located between the twin volcanic islands of Hunga Tonga and Hunga Ha'apai, part of a cluster of dozens of undersea volcanoes about 10 kilometers off the island of Tongatapu. Tonga's 170 islands are part of the Pacific Ring of Fire. The eruption, which has been ongoing since Monday, was initially heralded by a series of earthquakes.

USGS fights false Yellowstone warning

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

Blogging on EARTH

Unsubstantial warnings don’t fly with the U.S. Geological Survey. Following the recent swarms of earthquakes at Yellowstone, the website www.worldwaterplan.com issued a “legitimate-looking” warning using the USGS logo that suggested immediate evacuation. USGS says the warning is bogus, and now the government is pursuing legal action against the site’s creator.