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hazards

Comment: How much hazard mitigation is enough?

Given society’s finite resources, communities face the tough challenge of deciding how much mitigation is enough. Prioritizing is always hard, but it is especially difficult because of the limited ability to forecast future natural hazards. But there are ways to figure out the optimal amount of mitigation.

20 Nov 2014

Solar storms cause spike in electrical insurance claims

On March 13, 1989, a geomagnetic storm spawned by a solar outburst struck Earth, triggering instabilities in the electric power grid that serves much of eastern Canada and the U.S. The storm led to blackouts for more than 6 million customers and caused tens of millions of dollars in damages and economic losses. More than 25 years later, the possibility of such a catastrophe still looms, and the day-to-day effects of space weather on electrical systems remain difficult to quantify. Now, a new study correlating electrical insurance claims with geomagnetic data suggests that even moderate space weather may play a significant role in destabilizing the power grid.

09 Nov 2014

Benchmarks: November 8, 2013: Super-typhoon Haiyan tests Philippines warning protocols

On the morning of Nov. 8, 2013, Super-Typhoon Haiyan struck the east-central Philippines with sustained wind speeds exceeding 300 kilometers per hour. In a mere eight hours, the storm cut a path of total devastation over an area of 300 square kilometers, an area roughly the size of Seattle. More than 7,800 people were confirmed dead or missing and 27,000 injured; more than 4 million were displaced from their homes. Economic losses to homes, infrastructure and agriculture reached more than $12 billion (U.S.).

08 Nov 2014

Russian earthquake ruptures superfast and deep

A “superfast” magnitude-6.7 earthquake was detected off the coast of Kamchatka, Russia, in May. The earthquake, called a “supershear” quake, is one of a handful of superfast earthquakes noted by researchers over the years, but this is the first identified at such great depth.

24 Oct 2014

We're all living in the global aftershock zone

Can a large earthquake trigger another quake hundreds or even thousands of kilometers away? The answer, scientists say, appears to be yes, but when it happens is far from predictable. How does such dynamic triggering affect global earthquake hazards? Perhaps the whole world should be considered an aftershock zone.

19 Oct 2014

Remote triggering of ice quakes

On Feb. 27, 2010, a magnitude-8.8 earthquake struck the subduction zone off the coast of Chile. The resulting Rayleigh surface waves rippled around the world, triggering small earthquakes in many different tectonic settings, including Antarctica. As the surface waves moved across the white continent, a third of Antarctic seismic stations reported shaking coming from so-called “ice quakes.”

19 Oct 2014

Triggered tremor along the San Andreas Fault

The San Andreas Fault (SAF) in California is one of the most active in the U.S., but the 1,300-kilometer-long strike-slip fault seems to only be susceptible to small-scale dynamic triggering. After the magnitude-9 Tohoku quake in Japan in 2011, the SAF experienced an elevated incidence of tremor up and down its length. The tiny tremors were recorded at depths between 16 and 30 kilometers, below the fault’s seismogenic zone.

19 Oct 2014

Casting a seismic shadow

In the week or two before the magnitude-8.6 Indian Ocean earthquake in 2012, Earth was unusually quiet, with few large quakes over magnitude 5. Afterward, seismic activity all over the globe was elevated for more than a week. Then, suddenly, global seismicity dropped off precipitously: Beginning two weeks after the mainshock, no earthquakes of magnitude-6.5 or greater occurred for 95 days.

19 Oct 2014

Kilauea eruptions could shift from mild to wild

Hawaii’s Kilauea volcano is famously effusive: Low-viscosity lava oozes out of the main caldera and two active rift zones along the southern shore of the Big Island. But scientists suspect that Kilauea’s eruptions haven’t always been so mild, and a new study is providing further evidence supporting that notion. In the past 2,500 years, at least two cycles of explosive eruptions lasting several centuries each have rocked the island. The switch from effusive back to explosive is likely to occur again, scientists say, but probably not anytime soon.
 

14 Oct 2014

Benchmarks: October 9, 1963: The Vajont Landslide kills 2,500 in Italy

In 45 seconds, everything changed. What had been a towering mountainside collapsed into a pile of rubble; what had been a deep reservoir of placid water became a lethal flood; what had been a valley of small Italian villages was leveled to a barren outwash plain.

09 Oct 2014

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