This photograph shows the manipulator arm on one of MBARI’s remotely operated vehicles (ROVs) holding what looks like a chocolate brownie with a strange, spiky frosting. This is actually a chunk of basalt, a common type of volcanic rock, which MBARI geologists collected from the Endeavor segment of the Juan de Fuca Ridge, 7,300 feet below the ocean surface and 180 miles off the coast of Washington state. This rock may have been part of a hardened lava crust on a pool of molten lava created by an underwater volcanic eruption. At some point the molten lava drained out of the pool, leaving the hardened crust behind. The lava spikes on this rock probably formed on the underside of the crust (pointing downward), as the last remnants of the molten lava dripped down from the ceiling of the pool and solidified in the near freezing water of the deep sea. 

This photograph shows the manipulator arm on one of MBARI’s remotely operated vehicles (ROVs) holding what looks like a chocolate brownie with a strange, spiky frosting. This is actually a chunk of basalt, a common type of volcanic rock, which MBARI geologists collected from the Endeavor segment of the Juan de Fuca Ridge, 7,300 feet below the ocean surface and 180 miles off the coast of Washington state. This rock may have been part of a hardened lava crust on a pool of molten lava created by an underwater volcanic eruption. At some point the molten lava drained out of the pool, leaving the hardened crust behind. The lava spikes on this rock probably formed on the underside of the crust (pointing downward), as the last remnants of the molten lava dripped down from the ceiling of the pool and solidified in the near freezing water of the deep sea. 

Tags: ocean oceanography deep sea science lava volcano