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hazards

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

With examples of every type of volcano on Earth — each with its own eruptive pattern — Iceland presents a special challenge to volcanologists, but also serves as an ideal natural laboratory for studying how volcanic processes evolve.

29 Mar 2016

Eerily quiet Katla

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.

29 Mar 2016

Hekla the heckler

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.

29 Mar 2016

Benchmarks: March 17, 1944: The most recent eruption of Mount Vesuvius

Four-and-a-half years into World War II, the residents of San Sebastiano, Italy — a Neapolitan village on the western slopes of Mount Vesuvius — had already endured much misery: dictatorial rule, invasion, occupation and bombings. In mid-March 1944, they faced yet another catastrophe, this one a natural disaster that would destroy their town.

17 Mar 2016

Protracted drought threatens California levees

Levee failures are most often associated with the onslaught of water from large storms, such as Hurricane Katrina, whose landfall in 2005 caused more than 50 floodwalls and levees around New Orleans to fail.

But the lack of water can also weaken these critical earthen structures, according to recent research presented last December at the fall meeting of the American Geophysical Union in San Francisco. 

15 Mar 2016

Hidden double earthquake spells trouble for tsunami-warning systems

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.
 
06 Mar 2016

How supervolcanoes are set off

If a supervolcano were to erupt today, its impacts could be catastrophic. Fortunately, no such eruption has occurred during human history. The lack of eyewitness accounts, however, makes it difficult for scientists to understand how supervolcanoes evolve and erupt. Based on a recent modeling, researchers have offered a new hypothesis for how supervolcano eruptions might be triggered by external, rather than internal, forces.

01 Mar 2016

Uranium contamination in aquifers could be linked to nitrate

Nitrogen is an essential nutrient for plant life, but plants can only take up so much so fast. When excess nitrogen enters the environment by way of fertilizer and manure runoff, as well as in automobile and industrial emissions, it becomes a pollutant that can leach into waterways, carrying with it unintended — and often undesirable — consequences. In a new study, researchers have found evidence of one such consequence: elevated uranium levels in two major U.S. aquifers.

17 Feb 2016

Slipping point: Snow scientists dig in to decipher avalanche triggers

Scientists are studying avalanche triggers to understand how, where and when avalanches may occur. They’re starting to get a handle on the structure of packed snow and how avalanches fail and propagate.

15 Feb 2016

Revealing potential tsunami inundation on California coast

Earthquakes are well known along Southern California’s coast, and existing hazard maps indicate where quake-triggered tsunamis could flood the coastline. But in a new modeling study published in Geophysical Research Letters, researchers found that an earthquake-generated tsunami northwest of Los Angeles may reach farther inland than is currently projected.
 
06 Feb 2016

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