If past is prelude, then the volcanic eruption in Iceland whose plume of ash has grounded almost 300 flights across Europe may not only affect air travel in the coming days, it may also have a lingering impact on Europe’s weather. Experts are looking back to the aftereffects of a previous eruption–when the Laki volcano in Southern Iceland exploded more than 200 years ago. That explosion had catastrophic consequences for weather, agriculture and transport across the northern hemisphere – and helped trigger the French revolution [The Guardian].
The Laki volcanic fissure erupted over a eight month period between June 1783 and February 1784. Within Iceland, the lava and poisonous clouds of gas ushered in a time known as the “Mist Hardships”: farmland was ruined, livestock died in vast numbers, and the resultant famine killed almost a quarter of the population.
The eruption’s impact wasn’t confined to Iceland alone. Dust and sulfur particles thrown up by the explosion were carried as a haze across Northern Europe, clouding the skies in Norway, the Netherlands, the British Isles, France, Germany, Italy, and Spain. In conjunction with another volcanic eruption and an unusually strong El Nino weather pattern, the Laki eruption is thought to have contributed to extreme weather across Europe for the next several years.
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A magnitude 6.9 earthquake struck China’s southern Qinghai Province this week. The death toll now stand at more than 600, and rescuers pulled more than 1,000 people from the rubble alive. But, geologists say, this quake doesn’t seem linked to the massive one that shook the nearby province of Sichuan two years ago.
“It’s not the same fault, it’s a consequence of the same bit of global tectonics, which is the collision of India with Asia. That’s the only link I’d make,” said Dr David Rothery [BBC News]. The May 2008 Sichuan earthquake resulted from a thrust fault, which happens frequently in the region near the Himalayas where India and Asia collided long ago. But although this week’s quake happened not far from there, Rothery says it was a strike-slip event, which happens when there is sideways movement along a fault line. That’s the type of event that caused the January earthquake in Haiti.
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The wave of high-profile seismic activity so far in 2010 has been another reminder that we humans could use all the help we can get in predicting earthquakes. This week in the Journal of Zoology, biologist Rachel Grant suggests a new way: Watch the toads.
Taking cues from the animal kingdom is not itself a new idea (not by a long shot): Reports of animal earthquake prediction are legion and they date back to at least 373 BCE, when historians record that animals including rats, snakes and weasels flocked out of Helice just days before a quake devastated the Greek city. More recently there have been reports of catfish moving violently, bees leaving their hive in a panic, and fish, rodents, wolves and snakes exhibiting strange behaviour before earthquakes [Nature]. While these anecdotes grab the imagination, the scatter-shot nature of earthquakes previously prevented anyone from documenting such animal behavior before, during, and after a quake.
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When small earthquakes rumbled beneath northern Texas in 2008 and again in 2009, scientists were puzzled. While they expect to see seismic activity in active zones like Haiti, Chile, and Turkey, where disasters have already struck this year, the area around Fort Worth, Texas sees only rare and tiny seismic activity. Now, some Texas seismologists are arguing that techniques used in conjunction with natural gas exploration provide a plausible explanation for what’s going on.
North Texas sits atop the Barnett Shale, one of the several giant layers of shale in the United States believed to hold a truly massive amount of natural gas. The U.S. Geological Survey estimates that 200 trillion cubic feet of natural gas may reside in shales nationwide [USA Today]. The reason these giant deposits have remained largely untapped, however, is that shale isn’t particularly porous, and so extracting it requires drillers to fracture the rock in multiple places.
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The magnitude 8.8 earthquake that rocked Chile on February 27th didn’t just move the Earth’s axis, thereby shortening the day by 1.26 microseconds, but it also caused entire cities to shift their geographical location.
Studying precise GPS images of the area struck by the quake, a team led by earth scientist Mike Bevis discovered that the Chilean city of Concepción had moved 10 feet to the west. The epicenter of the quake was 71 miles northeast of Concepción, which is Chile’s second largest city.
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Will we ever get a solid answer on what killed the dinosaurs? According to a new “K-T Boundary Dream Team” comprising of 41 international experts, including geophysicists and paleontologists, yes, the question has been settled: An asteroid is indeed to blame.
For years, scientists have argued over different theories of what killed the dinos–including one hypothesis that has gained ground recently, which suggests that massive volcanic activity in India’s Deccan Traps wiped them out 65 million years ago. However, the latest expert panel stuck to the asteroid theory, saying a massive impact wiped out the dinos and more than half of the Earth’s other species. The panel’s review was published in the journal Science.
After studying all the available data on the Cretaceous-Tertiary (K-T) mass extinction, the panel concluded that the catastrophic event was caused by a 6-mile-wide asteroid that struck Earth at an angle of 90 degrees and a speed of about 12.4 miles per second – about 20 times faster than a speeding bullet [Guardian]. The asteroid hit Chicxulub, Mexico, with a force one billion times more powerful than the atomic bomb at Hiroshima [Science Daily News].
The impact of the crash would have triggered large scale fires, landslides, earthquakes that measured 10 on the Richter scale, and subsequent tsunamis, scientists said. Debris loosened by the impact would have shrouded the planet, clouding the skies, causing a global darkness, and “killing off many species that couldn’t adapt to this hellish environment” [Science Daily News], according to study coauthor Joanna Morgan.
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Less than two months after the earthquake that shook Haiti, and only hours after a quake causing small tsunamis occurred near Japan, the largest of 2010′s seeming barrage of big seismic events hit Chile. The 8.8 earthquake is the fifth largest since 1900. “We call them great earthquakes. Everybody else calls them horrible,” said USGS geophysicist Ken Hudnut. “There’s only a few in this league” [AP].
According to seismologists, the confluence of earthquakes these last couple months are probably coincidental; they’re all separated by too great a distance to be directly related. However, some say the latest quake is related to the 1960 quake in Chile that remains the largest ever recorded, a 9.5 on the Richter scale. Both earthquakes took place along a fault zone where the Nazca tectonic plate, the section of the earth’s crust that lies under the Eastern Pacific Ocean south of the Equator, is sliding beneath another section, the South American plate [The New York Times]. That massive event increased stress on other parts of the fault line, which continued to increase as the two plates converged at three and a half inches per year.
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NASA is sending a radar-equipped jet to conduct flights over Haiti and the Dominican Republic to capture 3-D images that could help predict future earthquakes. An estimated 170,000 people were killed in the 7.0 earthquake that battered Haiti on January 12. Unfortunately, experts predict more quakes as the country is situated in a seismically volatile zone.
A Gulfstream III jet is now on its way to map Haiti and the Dominican Republic, the two nations that share the island of Hispaniola. The Uninhabited Aerial Vehicle Synthetic Aperture Radar, or UAVSAR, was originally on its way to Central America to study volcanoes, forests, and Mayan ruins, but on its way south it will now also study Hispaniola’s fault lines.
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For years, farmers in Kenya’s arid north have suffered huge losses when droughts wiped out their cattle herds. Now, they have a means to protect their sole source of livelihood when rains fail and grasslands disappear. A new insurance scheme hopes to safeguard cattle-rearers in northern Kenya’s drought-prone Marsabit district by using satellite imagery to track changing landscapes and the subsequent loss of cattle.
The program, launched by the International Livestock Research Institute, is being billed as the world’s first insurance program to track changing pastoral grounds. When the satellite photos reveal that a verdant green landscape has changed to a dry brown, the insurance kicks in and farmers can collect their payments. The program will make things easier for insurance companies–for whom estimating losses in the past has been all but impossible. Partly because it has simply been too expensive for insurers to go and count the number of dead animals which might be spread over a vast rural area [BBC]. The scheme’s launch comes at a time when the Marsabit region has suffered 28 droughts in the last 100 years and four in the past decade alone [Kenya Broadcasting Corporation].
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In the aftermath of Haiti’s devastating earthquake, nervous citizens can be forgiven for wondering where the next Big One will hit. Major quakes strike with alarming regularity: Earthquakes of magnitude 7 or greater occur approximately 18 times a year worldwide. They usually originate near faults where tectonic plates —tremendous fragments of the earth’s crust—collide or push above or below each other.
Geologists suspect that Haiti’s destructive quake resulted from 250 years of seismic stress that has been building up between the North American and Caribbean tectonic plates. In fact, a group of U.S. geologists presented a study in the Dominican Republic (which shares the island of Hispaniola with Haiti) in 2008 saying that the region was at risk of an earthquake potentially even bigger than last week’s magnitude 7.0 quake. Part of their presentation is particularly chilling in light of what would happen less than two years later: “This means that the level of built-up stress and energy in the earth could one day be released resulting in an earthquake measuring 7.2 or more on the Richter Scale. This would be an event of catastrophic proportions in a city [Port-au-Prince] with loose building codes, and an abundance of shanty-towns built in ravines and other undesirable locations.”
Earthquakes are still impossible to predict with precision; in the words of one of the geologists who predicted the Haiti quake, “It could have been the next day, it could have been 10 years, it could have been 100… This is not an exact science.” But researchers have identified a handful of seismic zones around the globe that are storing up especial amounts of stress and are particularly hazardous. Browse through the gallery for a world tour of the planet’s most seismically vulnerable regions.
By Aline Reynolds
Image: USGS
Manoj Nair of the National Oceanic and Atmospheric Administration has devised a new possible method of detecting a deadly tsuami long before the wave crests to dangerous heights. And, in a bit of good news, much of it is already in place.
In a new study in next month’s Earth, Planets, and Space, Nair modeled the massive 2004 tsunami in the Indian Ocean and found that a tsunami picking up steam as it moves across the ocean emits a tiny electromagnetic signature of of about 500 millivolts. That’s enough to have an effect on the communication cables that stretch across the ocean floor, carrying internet messages and phone calls. The electromagnetic signal “is very small compared to a 9-volt battery, but still large enough to be distinguished from background noise on a magnetically quiet day,” said Nair [Daily Camera].
Nair says this kind of system could be a lower-cost alternative to the bottom pressure arrays that directly measure large movements of water. “What we argue is that this is such a simple system to set up and start measuring,” Nair says. “We have a system of submarine cables already existing. The only thing we probably need is a voltmeter, in theory” [Wired.com].
Oleg Godin, one of Nair’s research partners, said any small improvement could make a huge difference. “If you detect tsunamis in the deep ocean — and that’s what we’re working on — meaning far from shore, you have hours, certainly tens of minutes, to warn people,” he said. “If people are well educated, a 15-minute warning is enough to save everybody” [Daily Camera].
Related Content:
80beats: South Pacific Tsunami Kills More than 100 People
80beats: Geologists Find One Cataclysmic Tsunami in Every 600 Years of Thai Dirt
80beats: Haiti Earthquake May Have Released 250 Years of Seismic Stress
Image: flickr / epugachev
Satellite photos that have just been released reveal the scope of the physical destruction wrought by the 7.0 earthquake that struck the Haitian capital of Port-au-Prince on Tuesday. The human toll of is still unknown–but with much of the city reduced to rubble, experts say tens of thousands of people may be dead.
This image shows roads covered with debris from collapsed structures, and the white-colored National Palace with damage visible along the roof line. The image was taken by the GeoEye-1 satellite from 423 miles up in space on Wednesday morning.
Image: GeoEye
As Haiti reels from yesterday’s massive earthquake and its continued aftershocks, and nations rush to put rescue efforts together, scientists analyzing the seismic event say this disaster may have been a long time coming.
The earthquake in Haiti had a preliminary magnitude of 7.0 and it appeared to have occurred along a strike-slip fault, where one side of a vertical fault slips horizontally past the other, scientists say [AP]. This fault, called the Enriquillo-Plantain Garden fault, may have been slowly building up pressure since the major 1760 earthquake that struck Haiti.
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Twitter: Bane of employers … but friend of science?
At a scientific meet-up in California this week, researchers with the U.S. Geological Survey proposed that the 140-character micro-blogging site could help to speed up responses to earthquakes. “Why would such a system work?” asked Paul Earle, a geologist at the USGS, at the American Geophysical Union fall meeting Monday. “Because people like to tweet after an earthquake” [Wired.com].
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Dreams that major geothermal energy plants could power our future took a major hit last week, as worries over earthquakes and technical failures killed two ambitious projects in consecutive days. The two projects both hoped to harvest the heat of deeply buried bedrock by drilling down, fracturing the rock, and then circulating water through the fissures to produce steam that could drive turbines.
First, on Thursday, the $60 million plan to tap geothermal energy beneath Basel, Switzerland, died for good after a Swiss government study said it would cause millions of dollars in damage through earthquakes each year. The project, led by Markus O. Häring, a former oilman, was suspended in late 2006 after it generated earthquakes that did no bodily harm but caused about $9 million in mostly minor damage to homes and other structures. Mr. Häring is to go to trial next week on criminal charges stemming from the project [The New York Times].
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