Earthquake Births New Island off Pakistan

by | Dec 18, 2013

On Sept. 26, 2013, the Advanced Land Imager on NASA's Earth Observing-1 satellite captured the top image of Pakistan's new island, which sits roughly 0.6 miles offshore. The bottom image, acquired by the Operational Land Imager on the Landsat 8 satellite, shows the same area on April 17, 2013. The aerial photograph (inset) provides a close-up of the landform.

On Sept. 24, 2013, a major earthquake rattled western Pakistan, killing at least 350 people and leaving more than 100,000 homeless. Amidst the destruction, a new island was created offshore in the Paddi Zirr (West Bay) near Gwadar, Pakistan.

Likely a mud volcano, the island rose from the seafloor near Gwadar on Sept. 24, shortly after the earthquake struck about 230 miles inland. In the accompanying satellite images, lighter shades of green and tan in the water reveal shallow seafloor or suspended sediment. The water depth around the new island is roughly 50 to 65 feet, according to Asif Inam of Pakistan's National Institute of Oceanography. The aerial photograph provides a close-up of the landform, estimated to stretch 250 to 300 feet across and standing 60 to 70 feet above the water line. The surface is a mixture of mud, fine sand and solid rock.

The island is really just a big pile of mud from the seafloor that got pushed up, said Bill Barnhart, a geologist at the U.S. Geological Survey who studies earthquakes in Pakistan and Iran. This area of the world seems to see so many of these features because the geology is correct for their formation. You need a shallow, buried layer of pressurized gas”methane, carbon dioxide or something else”and fluids. When that layer becomes disturbed by seismic waves (like an earthquake), the gases and fluids become buoyant and rush to the surface, bringing the rock and mud with them.                                         


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