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natural hazards

Resolving a misplaced source of volcanism in the Galapagos

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.

07 Apr 2014

Social sciences improve tornado warnings

In 2013, 55 people in seven states were killed by tornadoes. Now, scientists behind a new report analyzing the effectiveness of tornado-warning processes are hoping to help reduce tornado fatalities in the 2014 storm season by combining the latest storm-tracking technology with a better understanding of how communities and people respond to tornado warnings.

03 Apr 2014

Massive earthquake strikes Chile

A massive magnitude-8.2 earthquake struck off the coast of Chile about 95 kilometers north of Iquique on Tuesday night at 6:46 p.m. local time, according to the U.S. Geological Survey (USGS). Because the quake occurred underwater along a thrust fault in the subduction zone, a tsunami warning was issued for several cities along the Chilean coast and around the Pacific Basin. A 2.1-meter wave was reported in some Chilean cities. Preliminary reports indicate several deaths and some damage; power is out in many areas and landslides have also been recorded, according to news reports. So far, widespread destruction — which could easily accompany such a large quake — has thankfully not been reported.  The quake followed weeks of increased seismic activity, including dozens of earthquakes up to magnitude-6.7 that have struck since March 16. It is now clear these were foreshocks. 

02 Apr 2014

Volcanic lightning generated in a bottle

Scientists 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.

06 Apr 2014

GPS measurements of ground inflation help forecast ash plumes

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.

20 Feb 2014

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

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. Beginning at 5:36 p.m., intense ground shaking continued for almost five minutes as the most powerful earthquake ever recorded in North America struck 22.5 kilometers beneath Prince William Sound, where the Pacific Plate is subducting beneath the North American Plate. The shaking — felt over an area of more than 1.3 million square kilometers — was so severe and long-lived that some survivors later said they first thought the Soviet Union had dropped a nuclear bomb on Anchorage, 120 kilometers northwest of the epicenter.

27 Feb 2014

A tsunami by many other names

Storm-triggered waves have been recognized and recorded around the world, including the U.S. where, in addition to the Great Lakes, they have occurred in New England, on the West Coast and on the Gulf Coast. In some parts of the world, they are common enough to have special names. In Croatia, the phenomenon is called Šćiga; in Malta, it is Milghuba; in Spain, Rissaga; in Japan, Abiki; and in Finland, Seebär. Scientists everywhere call them meteorological tsunamis, or meteotsunamis. Here are a few notable occurrences:

19 Feb 2014

A history of tsunami-like waves on the Great Lakes

Severe and deadly seiche events are rare on the Great Lakes. In the last century, about 10 major waves have hit the shores of the Great Lakes, but smaller anomalous waves occur much more frequently. Many of the deadliest have occurred on Lake Michigan, but Lakes Superior, Huron and Erie have also experienced them. In addition to the June 26, 1954, event, some others were: 

19 Feb 2014

Tsunamis from the sky: Can meteotsunamis be forecast?

The Great Lakes, along with the U.S. East Coast, the Mediterranean, Japan and many other parts of the world, have a long history of mysterious large waves striking unsuspecting coastlines. Such waves have characteristics similar to tsunamis triggered by earthquakes or landslides. Only recently, however, have scientists unraveled how a storm can create and propagate these far-traveling waves — called meteorological tsunamis or meteotsunamis. 

19 Feb 2014

Warring trolls explanation for mysterious basalt pillars revised

Peculiar basalt pillars found in Iceland — attributed in local lore to a pair of angry trolls hurling projectiles at each other — are having their origin story updated. In a rare example of nonexplosive lava-water interactions occurring on land, the hollow pillars likely formed around vertical columns of steam and superheated water venting through lava as it flowed over saturated ground, according to a new study.

02 Feb 2014

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