On Tuesday, September 25, 2013, a major earthquake rattled the sparsely populated south-central mountainous region of Pakistan in the late afternoon, killing at least 300 people, likely injuring hundreds of others, and destroying numerous homes.
But that’s not all. The earthquake also birthed a small island less than a football field in length in the Arabian Sea. Located less than a mile from shore, some scientists believe the island is a mud volcano, a mix of mud, rock and gases that erupted out of the sea floor due to underground pressure changes and plate movement triggered by the area’s earthquake.
Last week’s 7.7 magnitude earthquake is the most recent in a string of destructive quakes that have struck Pakistan in the last decade: A magnitude 7.2 earthquake hit in 2011, a magnitude 6.4 quake rumbled in 2008, and a magnitude 7.6 event occurred in 2005. But it has been around sixty years since a Pakistani earthquake last resulted in the creation of an ephemeral small rocky island in the Arabian Sea.
Mud volcanoes, also called mud domes, are often found in volcanic regions, and generally take the shape of a kitchen chair-size cone, with liquid mud oozing out like hot fudge or being burped into the air. The expelled muddy cocktail forms when hot gases push through the ground, melting the rock and creating an earthy slurry.
These geological features can form outside of volcanic areas, too, such as along tectonic boundaries. This was the case in Pakistan, where there are several converging continental plates and no lava-filled volcanoes.
One of the largest known mud volcano was created in Java, Indonesia in 2006 and is called “Lusi.” The spewing feature, which measures about 6 miles in diameter and climbs up to 2,300 feet tall, proved catastrophic—inundating homes with a persistent dirty deluge. That mud dome was likely also formed from a regional earthquake—and not by oil drilling activities as initially speculated.
Located out at sea, Pakistan’s potential mud volcano does not pose a significant danger to its denizens. However, authorities have advised people not to visit the island, for fear of toxic gas emissions.
Scientists have also said the island could be the result of landslide, not a mud volcano. Check back here in the upcoming weeks for news of the final scientific verdict: landslide or mud volcano.