Causes of Pakistan's New Island Revealed

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The powerful earthquake that hit Pakistan on Tuesday (Sept. 24) and killed more than 320 people struck along one of the most hazardous yet poorly studied tectonic plate boundaries in the world.

The magnitude-7.7 earthquake was likely centered on a southern strand of the Chaman Fault, said Shuhab Khan, a geoscientist at the University of Houston. In 1935, an earthquake on the northern Chaman Fault killed more than 30,000 people and destroyed the town of Quetta. It was one of the deadliest quakes ever in Southeast Asia. Shaking from yesterday's earthquake in Pakistan demolished homes in the Awaran district near the epicenter, according to news reports. The death toll will likely rise as survivors and emergency workers search the debris. In the hours after the quake, a new island suddenly rose offshore in shallow seas near the town of Gwadar, about 230 miles (380 kilometers) southwest of the epicenter. Geologists with the Pakistan Navy have collected samples from the rocky pile, the Associated Press reported. From pictures and descriptions, many scientists think the mound is a mud volcano, which often erupt after strong earthquakes near the Arabian Sea. A second island has also been reported offshore of Ormara, about 170 miles (280 km) east of Gwadar, Geo News said. "Other mud volcanoes have been triggered at this distance for similar size earthquakes," Michael Manga, a geophysicist and expert on mud volcanoes at the University of California, Berkeley, told LiveScience's OurAmazingPlanet. The unexplained island may have focused unusual global attention on the earthquake, which hit in a region that frequently experiences devastating temblors. But despite the hazards faced by millions living near the Chaman Fault, a combination of geography and politics means the seismic zone remains little studied. The Taliban killed 10 climbers, including an American, in northern Pakistan in June. "Its location is in an area that is very difficult to do any traditional field work," Khan told LiveScience's OurAmazingPlanet. "I tried twice to submit proposals to (the National Science Foundation) and I got excellent reviews, but the review panel said I was risking my life to work in that area." But the National Academy of Sciences felt differently. With their support, Khan and his colleagues in Pakistan and at the University of Cincinnati are now studying the fault's current and past movement. This will help the researchers forecast future earthquake risk. "This fault has had very little work and no paleoseismology," Khan said. "It is really important."