A small island has emerged off the southern coast of Pakistan after a 7.7 magnitude earthquake struck the country.

Reuters reports that "a crowd of bewildered people [gathered] on the shore to witness the rare phenomenon."

[UPDATE 19:00 EDT] Nidhi Subbaraman of NBC asked some experts:

Seismologists suspect the island is a temporary formation resulting from a "mud volcano," a jet of mud, sand and water that gushed to the surface as the [earthquake] churned and pressurized that slurry under the ocean floor.

The official death toll from the quake is 328 (and rising), and many of the buildings in the impoverished area of the Baluchistan province have caved in.

Pakistani TV Geo News, citing Pakistan's deputy inspector general, reported that the 20-to-40-feet-high and 100-feet-wide island arose out of the Arabian Sea about 350 feet off the coast of Gwadar.

The epicenter of the quake was about 320 miles to the northeast.

Here's where Gwadar is located: