John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
A burbling volcano of mud rose out of the Arabian Sea like some Lovecraftian nightmare.
Gwadar is a developing city of 85,000 souls on Pakistan's southern coast that until recently didn't have a prominent view of a huge, horrible sludge-nipple poking out of the water. The powerful earthquake of September 24 fixed that, however, shaking the region so hard it spawned a fire-licked mountain in the Arabian Sea.
This odd geological formation rose like a Lovecraftian nightmare shortly after the shaking died down from the 7.7-magnitude quake, which killed more than 350 people and left homeless an additional 100,000. Located about a half-mile offshore, the slimy behemoth surfaced so quickly it kidnapped a bunch of marine life, cooking to death mussels and a large manta ray in the harsh Middle Eastern sun.
Here's the blank zone it came from in April 2013, as seen by America's Landsat 8 satellite:
And this was the orbiter's view on September 26. Note the island's halo of submerged bulk, as pale whitish-green as a rotting fish's belly:
Locals who boated out to stand on this unasked-for landmark like explorers claiming a new continent found it rife with noxious vapors bubbling from the mud. When put to the match, these streams of methane erupted into little blowtorches. The blob of sea-crud, which measured up to 300 feet wide and 70 feet deep, is riddled with explosive gases, a fact that allowed it to form in the first place. Explains NASA:
"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."
[Pakistani geologist Asif] Inam asserted that 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. On the new island, there is a continuous escape of the highly flammable methane gas through a number of vents."
For folks who noticed the use of plurals, yes, a U.S. satellite has caught this kind of island birthing before. The process is weird enough to see from space, but down at sea level it's an actual freaky menace to vessels. "Mud volcanoes and islands are a natural hazard and threat to navigation," notes Inam.
Have a look at the intriguing surface of the fetid mound; a larger animation is posted here: