Chile on EARTH Magazine

Easter Island inhabitants drank brackish water to survive

Thu, 17 Jan 2019 13:33:07 -0500

Graduate student Tanya Brosnan, who led a recent study of coastal seeps — where fresh groundwater flows into the ocean — on Rapa Nui (Easter Island), carries out conductivity measurements near Ahu Tongariki on the east side of the island. Credit: Carl Lipo.

The remote Chilean island of Rapa Nui, also known as Easter Island, is famous for its 961 giant stone statues and monuments, erected between 1200 and 1600. Called moai, these statues have been a mystery for years, especially considering just a few thousand people inhabited the small, resource-limited Pacific island nearly 3,700 kilometers west of Chile. “Why did people put the statues where they did?” asks Carl Lipo, an archaeologist at Binghamton University in New York. The answer, according to new research, may have something to do with the civilization’s water supply.

Residual strain explains later quakes

Mon, 19 Mar 2018 14:12:33 -0400

The Nazca Plate, moving eastward at a rate of 6.6 centimeters per year, collides with, and dives beneath, the South American Plate off the Chilean coast, building strain. Credit: K. Cantner, AGI, after GEBCO world map 2014, gebco.net.

The largest earthquake in recorded history struck southern Chile on May 22, 1960. The magnitude-9.5 temblor was followed by a tsunami that, combined with the seismic shaking, killed 1,600 people and left more than 2 million homeless. New research suggests that, despite the staggering size of the event, the shaking didn’t dissipate all the strain accumulated at the time on the subduction fault between the Nazca and South American tectonic plates. The residual strain left on the fault may explain why a portion of this same section of fault ruptured again — 56 years later — on Dec. 25, 2016, in a magnitude-7.6 event.

Transitional Chilesaurus fills gap between major dinosaur groups

Wed, 15 Nov 2017 14:46:28 -0500

Chilesaurus, which lived during the Late Jurassic, was an early ornithiscian dinosaur that shared traits with other ornithischians as well as with theropods, according to new research. Credit: Nobu Tamura.

In 2015, a new dinosaur was discovered in southern Chile, but its odd set of characteristics left paleontologists scratching their heads: Was it a carnivore or an herbivore? A closer look at the bones of the dinosaur, named Chilesaurus, is helping scientists determine how it fit into the Late Jurassic landscape.

Getting there and getting around Patagonia

Tue, 22 Aug 2017 15:22:02 -0400

Credit: Bottom: NASA/AGI.

There are many ways to get to Patagonia. I would have preferred to get there by following Charles Darwin’s route, aboard a replica of H.M.S. Beagle (especially considering that last year was the 200th anniversary of his birth). Sadly, the modern school calendar dictated that I move more quickly: Two weeks was all I had to work with.

Travels in Geology: Patagonia: The ends of the earth

Tue, 22 Aug 2017 14:52:16 -0400

The terminus of Grey Glacier in Torres del Paine National Park calves glaciers that accumulate downstream. Credit: Callan Bentley.

Certain place names conjure up a sense of remoteness that verges on the mythical: Timbuktu, Outer Mongolia, the Yukon. For me, prime among these legendary areas is Patagonia, a region of South America that encompasses much of the southern half of Argentina and Chile. But the exact borders are fuzzy: Where Patagonia starts and ends may lie more in the mindset of the traveler than in any physical landmark. You’ll know it when you get there.

Whirling "gravel devils" show wind can carry more than just sand

Thu, 15 Jun 2017 11:24:28 -0400

Abraded gypsum blades deposited by a gravel devil. Credit: Kathleen Benison.

A gypsum gravel devil swirls above the Salar Gorbea. Credit: Kathleen Benison.

Sand grains, by definition, are between 0.06 and 2 millimeters in diameter, and they are often thought of by scientists as the largest sediments that wind can transport, with larger sediments simply being too hefty for winds to keep aloft. But strong winds, particularly in tropical storms and tornadoes, are known to move objects far larger than sand over short distances. Now, in the high Andes of Chile on the Salar Gorbea salt flat, evidence has been found of tornadic “gravel devils” whipping across the landscape and transporting gypsum crystals as long as 27 centimeters.

Getting there and getting around Patagonia

Tue, 29 Nov 2016 19:24:04 -0500

High-pressure systems that bring clear skies are reasonably common during the winter in Chilean Patagonia, a region that is notorious for its foul weather. Credit: Lon Abbott & Terri Cook.

Southern Chile has two main gateways, the homey town of Puerto Natales, a 1.5-hour drive from the national park, and Punta Arenas, a small city about 4 hours’ drive to the south. Of the two, Punta Arenas (PUQ) has the larger airport, which hosts regular year-round flights from Santiago on LATAM and Sky Airline, an efficient regional carrier, plus occasional flights from Puerto Montt in Chile’s beautiful Lake District. Flights to Puerto Natales (PNT) only operate during the summer season. There are no direct flights from the U.S. to this region.

Travels in Geology: Exploring an icon of Patagonia: Chile's Torres del Paine National Park

Tue, 29 Nov 2016 19:14:13 -0500

Mount Almirante Nieto and the Torres del Paine reflect in the still waters of Lake Amarga. Credit: Lon Abbott & Terri Cook.

While planning a family trip to Chile last year, Torres del Paine (pronounced “PIE nay”), a group of impossibly steep granite spires, was number one on our Chilean travel list. Despite their reputation for some of the foulest weather on earth, the peaks are magnets for tourists and rock climbers from around the world. But considering that reputation, the park’s location at 51 degrees south latitude and the fact that we were going during the Southern Hemisphere winter, we reluctantly crossed it off our list and concentrated on destinations in the country’s comparatively balmy north. That was until our teenage son Logan, an amateur mountain meteorologist, excitedly shared with us the results of his Patagonian climate research. “Dad, Dad!” he exclaimed. “High-pressure systems with clear weather are more common in the Patagonian winter than in summer, and winter temperatures seldom drop far below zero Celsius!” That report got Dad on board. Mom, who is not fond of the cold, was a harder sell, but sister Kailas’ enthusiasm sealed the deal. We’d soon purchased inexpensive off-season air tickets from Santiago to Punta Arenas and booked a room at Hosteria Pehoé, a lodge on Lake Pehoé, the location for the iconic photos of spectacular peaks that made the park famous. We were hoping that the investment would pay off with at least one fleeting glimpse of the mighty peaks through the notorious mist.

Earliest Americans were wide-ranging wanderers

Fri, 19 Feb 2016 19:02:47 -0500

A pebble tool made out of serpentine, likely sourced from the coastal cordillera west of Monte Verde. It was made 17,000 to 19,000 years ago. Credit: Tom Dillehay.

About 40 years ago, when the Monte Verde archaeological site in southern Chile was dated to 14,800 years ago, conventional ideas of American anthropology were turned on their heads. Until then, the “Clovis First” theory, which held that modern humans only began populating the Americas from Asia via the Bering land bridge roughly 13,500 years ago, was widely accepted. That people had lived thousands of kilometers farther south more than 1,000 years before the Clovis culture arose came as a shock initially, but the idea, and the Monte Verde site, has gradually become accepted over time.

Hidden double earthquake spells trouble for tsunami-warning systems

Tue, 09 Feb 2016 08:33:17 -0500

Researchers found that a magnitude- 7.1 earthquake recorded on Jan. 2, 2011, was actually a closely spaced doublet of two similarly sized quakes. Credit: K. Cantner, AGI.

On Jan. 2, 2011, a magnitude-7.1 earthquake was recorded striking central Chile along the tectonic boundary between the Nazca and South American plates. Shaking from the quake was felt hundreds of kilometers from the epicenter, but no deaths or major damage were reported.

Subducting seamounts blocked a big quake in Chile

Thu, 07 Jan 2016 11:12:21 -0500

Map of Chile's coastline showing the locations of the April 2014 earthquake and the seamounts that may have prevented the rupture from propagating farther. Credit: K. Cantner, AGI, adapted from Geersen et al., Nature Communications, 2015.

Off the coast of Chile, the Nazca Plate is subducting beneath the South American Plate. Friction between the two plates creates stress along the contact area between them, which is occasionally released in the region’s frequent earthquakes. But the section of the megathrust fault near Iquique has been locked and accumulating stress since the last big event to strike that part of the fault in 1877.

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.

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.

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.

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.