November 6, 2011 - Submarine eruptions off El Hierro, Canary Islands

Submarine eruptions off El Hierro, Canary Islands

In early November, a submarine volcano continued to spill gas and volcanic debris into the Atlantic Ocean south of El Hierro, in the Canary Islands as earthquakes rocked the land northwest of the Island. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite captured this true-color image of the milky, yellow-green stained sea south of the island on November 2, 2011. On that same day, a magnitude 4.4 earthquake was reported in El Golfo Bay, a half-moon bay on the northern side of the island. The earthquake was followed by a strong harmonic tremor.

Tremors first began on the Island of El Hierro in July, becoming more frequent and stronger until early October, when the underwater eruption began. Reports from a recent underwater survey revealed an eruptive vent and crater about 150 meters (500 feet) below the surface, along with submarine “pillow” lava – a pillow-shaped lava that forms underwater. By November 3, there were reports of increased bubbling of the water above the eruption site, a phenomenon that some locals are calling a “jacuzzi”. On November 4, earthquakes increased, with 15 tremors of a magnitude 1.5 or greater reported between midnight at 8:30 UTC, and more during the rest of the day. On November 5, residents of La Restinga, a town about 7 kilometers north of the volcanic vent, were evacuated due to the increased activity in the area.

Image Facts
Satellite: Aqua
Date Acquired: 11/2/2011
Resolutions: 1km ( B), 500m ( B), 250m ( B)
Bands Used: 1,4,3
Image Credit: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC