On Sept. 24, 2013, a 7.7-magnitude earthquake rattled western Pakistan, leaving at least 350 people dead and than 100,000 homeless. The quake also created a new island near Gwadar, Pakistan.
“The island is really just a big pile of mud from the seafloor that got pushed up,” says 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.”
According to marine geologist Asif Inam of Pakistan’s National Institute of Oceanography, the underground pressure in this case came from expanding natural gas. “The main driving force for the emergence of islands in this part of the world is highly pressurized methane gas, or gas hydrate,” he says. “On the new island, there is a continuous escape of the highly flammable methane gas through a number of vents.”
Image courtesy of NASA.