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].
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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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A super-colossal volcanic eruption rocked Italy 39,000 years ago, and troubling signs at the site, now known as Campi Flegrei, have many scientists wondering when the next big one will hit. To probe the issue, so to speak, the Campi Flegrei Deep Drilling Project will drill nearly 2.5 miles down into the collapsed volcanic crater to find out if another blast is on the horizon. Though the researchers on this particular project point out that any risk is small, it will begin amid debate about whether such endeavours are safe, given the unknowns of a volcano’s interior. A few say drilling might even trigger a major eruption [New Scientist]. However, scientists on the project say this isn’t likely, as their drills won’t dig deep enough to set off an eruption.
Campi Flegrei isn’t well known because it lacks a volcanic cone, but it dwarfs Mount Vesuvius. All of Naples sits within its caldera, an eight-mile-wide collapsed area of land formed by the eruption 39,000 years ago. A similar volcanic eruption would leave large parts of Europe buried under ash, say scientists, however smaller eruptions occur every few centuries; the last eruption was in 1538. The researchers hope that by drilling into the volcano, they’ll learn if another smaller eruption is imminent. They hope to locate fracture zones and magma pools that could only be guessed at without drilling. This could show exactly where magma might ascend and collect prior to an eruption. Meanwhile, rock samples could be tested under high stresses in the lab to help model the ground deformation prior to eruption [New Scientist]. The caldera’s center has risen about 10 feet since the 1960s, which has lit a fire under the researchers since a similar rise proceeded a series of intense eruptions 4,000 years ago.
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From an ancient Peruvian civilization comes this warning: Don’t chop down all your trees, or there will be hell to pay.
The Nazca people are famous for the enormous earthworks they carved into an arid plateau, in designs that range from simple geometrical forms to representations of animals like hummingbirds, lizards, and monkeys. They were previously known to have disappeared around A.D. 500, when massive floods powered by El Niño ravaged the valley where they made their home. Now, a new study that examined the pollen in buried layers of soil in order to trace the horticultural history of the land may have revealed why those floods were so devastating.
The Ica Valley, about 120 miles south of Lima, is barren today but was once a riverine oasis — a fertile landscape capable of supporting many people. The key to that fertility was a tree called the huarango [Los Angeles Times]. The huarango tree provided wood for building and fuel, and seed pods that can be ground up and used in flour or beer. Its branches caught the water in morning mists, and its roots stabilized the topsoil. Says lead researcher David Beresford-Jones: “These were very special forests…. It is the ecological keystone species in the desert zone enhancing soil fertility and moisture and underpinning the floodplain with one of the deepest root systems of any tree known” [BBC News].
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Federal experts believe that a major earthquake could trigger fires at Los Alamos National Laboratory, releasing radioactive materials and endangering lives. The rupture of a seismic fault that runs underneath the lab would shake the ground more than scientists previously thought, according to a new report (PDF). A natural disaster here would be bad news, since the lab, just west of Santa Fe, is the main plutonium factory in the United States, believed to hold thousands of pounds of plutonium for use in nuclear weapons (the actual amount is classified).
Researchers study plutonium inside glove boxes—a Hollywood movie staple, consisting of a sealed enclosure with gloves so that someone outside the box can work on dangerous materials inside. A major earthquake would shake the ground enough to topple the glove boxes, says the new study. Some glove boxes are enormous and even contain furnaces to cast and mold plutonium. If one of these were to crash, the resulting fire would be uncontrollable and would create a vaporized plutonium cloud that could drift outside of the lab, says the safety report. In a worst-case scenario, a fire could release so much airborne plutonium that a person on the boundary of the lab would get a dose of radiation—potentially many thousands of times greater than a chest X-ray—that could be fatal in weeks, according to individuals knowledgeable about the study [Los Angeles Times].
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According to a theory proposed in 2007, the explosion of a comet over North America killed off the Clovis people and many of the continent’s largest mammals nearly 13,000 years ago. Not so fast, says a new study published in the Proceedings of the National Academy of Sciences, fueling a WWE-style stare down between the opposing camps.
The new report explains that archaeologists have examined sediments at seven Clovis-age sites across the United States, and found that the concentration of magnetic debris was insufficient to confirm an extraterrestrial impact at that time [Nature News]. The original theory’s evidence came from magnetic microspherules, or cosmic debris, discovered in sediments at 25 locations. However, one of the new study’s authors, Todd Surovell, said that even after 18 months of sedimentary analysis and hundreds of hours peering into a microscope, he could find no evidence of microspherules to support the the exploding comet theory. Snap.
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Some of the world’s baddest volcanoes, like Chile’s Chaitén volcano that erupted in 2008, are actually even worse than scientists previously thought. A study of Chaitén’s eruption revealed that locals only had 30 hours to to flee from first time they felt rumbling, not the weeks or months that it typically takes a volcano to go from tremors to eruption. That’s because Chaitén is a rhyolitic volcano; these volcanoes are largely fueled by a silica-based, very flow-resistant magma and they tend to build pressure over time before erupting violently [National Geographic News]. Thousands were able to escape before Chaitén’s blast, but scientists are warning that others living in the shadow of a rhyolitic volcano may not be so lucky.
The magma of the Chaitén volcano traveled up to 3 feet per second, according to the study published in Nature. It shot from a depth of more than five kilometres [3 miles] to the surface in about four hours…. The violent and unexpected nature of the blasts, together with their rarity, means the Chaiténeruption is the first rhyolite event to have been scientifically assessed in this way [ABC News]. In the U.S. there are large rhyolitic volcanoes in Wyoming, California, and New Mexico as well as in the Japanese islands and New Zealand’s Taupo Volcanic Zone. Scientists are saying that even though rhyolitic eruptions are rare, the study should serve as a warning call to step up monitoring of potentially active volcanoes.
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Image: Jonathan Castro
Here’s a timely piece of research that may inspire some trepidation, as it comes hard on the heels of Tuesday’s tsunami-triggering earthquake in the South Pacific and today’s destructive earthquake in Indonesia. Researchers have found evidence that major quakes can weaken faults on the other side of the world, increasing the chance of further tremors.
The researchers analyzed 20 years of data at Parkfield, which sits on the mighty San Andreas Fault halfway between Los Angeles and San Francisco. It’s the most studied earthquake zone in the world, rigged with sensitive instruments to detect minute changes in the Earth’s crust [AP]. In 2004, the seismic records showed a change beginning shortly after the 9.3 magnitude earthquake in Sumatra that caused a deadly tsunami.
There was an increase in the number of small “repeating earthquakes” that regularly shudder through the ground around the San Andreas fault. Study coauthor Taka’aki Taira says that “after Sumatra, the frequency changed – it increased – but the magnitude decreased. That is a signal of the fault weakening; you only have to push a little bit and the fault fails” [BBC News].
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The tsunami that struck the South Pacific islands of Somoa, American Somoa, and Tongo yesterday has resulted in at least 108 deaths, according to early reports.
Experts monitoring the underwater earthquake that triggered the tsunami have issued various reports of its magnitude, ranging from 7.8 to 8.3. The powerful quake struck early on Tuesday morning, local time, as island residents were getting ready for work and school. About ten minutes after the shock, ten-foot-high waves hit American Somoa’s shore. “American Samoa is a small island, and most of the residents are around the coastline,” [said Filipo Ilaoa, deputy director of the American Samoan office in Honolulu]. “There was no warning or anything at all. By the time the alert was out of the Pacific Tsunami Warning Center, it had already hit” [The New York Times].
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