HAZARDS

hazards

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

What are the odds?: Automated system calculates the likelihood that asteroids will hit Earth

By some estimates, Earth is pelted each year by tens of thousands of asteroids — from souvenir-sized nuggets 10 grams and up to the occasional meters-wide boulder. Spotting larger Earth-bound impactors that could cause serious destruction, while they’re still in space, has been a priority of the planetary science community for years. But many space objects are small enough that they can only be detected days or hours before impact — if at all. In a new study, scientists have tested and automated a new technique called systematic ranging that’s intended to rapidly calculate the probability — from only a handful of observations — that newly discovered asteroids will hit Earth.

26 Jan 2016

Subducting seamounts blocked a big quake in Chile

Chile, which lies above a massive subduction zone fault, is one of the world’s most earthquake-prone countries, experiencing nine temblors of magnitude 7 or greater since 2010. In April 2014, a magnitude-8.1 earthquake struck 95 kilometers northwest of the city of Iquique, but despite its large size, the event failed to release all the stress thought to have built up along that portion of the fault. A new study reveals that a ridge of ancient underwater volcanoes may have blocked the 2014 earthquake rupture from propagating farther, thus limiting the size of the quake.
 

 

20 Jan 2016

Widespread malaria risk from African dams

Large dams cause more than 1 million cases of malaria annually in sub-Saharan Africa, according to the authors of a new study published in Malaria Journal.
 
17 Jan 2016

Treated water that's too pure lets arsenic sneak in

With California’s water resources dwindling to alarmingly low levels, the Orange County Water District (OCWD) has pioneered a high-tech approach for recycling wastewater into potable tap water instead of discharging it into the ocean. The purification process is so thorough, however, that it might actually make the water too clean: In a new study, researchers have found that the ultra-purified water is vulnerable to contamination by naturally occurring arsenic in underground storage aquifers.
 
03 Jan 2016

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