Volcanoes

volcanoes

Modeling 'magma mush' could reveal volcanic histories

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.

18 Dec 2015

Opalescent pools shimmer beneath Santorini

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.
 
15 Nov 2015

Campi Flegrei makes its own concrete caprock

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? 
 
16 Oct 2015

Ancient floods degassed Lake Kivu

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.
 
16 Sep 2015

Volcanic lightning turns ash into glass

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.

07 Aug 2015

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

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.

13 Jul 2015

Down the Earth With: 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.

17 Apr 2015

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

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.

 
13 Apr 2015

Chaitén's vigorous volcanic history revealed

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.

29 Mar 2015

Down to Earth With: The USGS Landslide Response Team

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.

21 Mar 2015

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