Volcanic Eruption on Canary Island May Loom After Hundreds of Small Earthquakes

A string of earthquakes around the island of El Hierro in the Canary Islands has officials on alert for an underwater volcanic eruption.

El Hierro, the smallest and farthest south and west of the Canary Islands, has a population of about 10,000. Two years ago, a new underwater volcano appeared off the coast of the island after hundreds of earthquakes struck the area in a matter of days in July 2011.

Last week officials on the island announced that a new string of earthquakes and a sudden change in height of the new volcano could be a harbinger of eruption.

Shortly after the Dec. 27 announcement, El Hierro saw its largest earthquake ever - a 5.1 magnitude tremblor that struck off the coast at a depth of about 15 kilometers. Between Monday and Wednesday of last week, more than 500 earthquakes rattled the island which, like all of the Canary Islands, is a popular tourist destination.

The swarm of earthquakes has led to notable deformations in the earth around the island. One deformation lifted the ground 3 centimeters in 24 hours, according to data from Earthquake-Report.com, an independent earthquake reporting site.

"The changing deformation pattern shows the biggest magma movement below the island concentrating in the El Golfo area (Sabinosa to Frontera) and is an additional sign that the crisis isn't over yet," Earthquake-Report said Monday.

As of Monday no new earthquakes have occurred in the region, but the volcanic eruption risk remains "yellow."

"This warning means that activity is increasing at the volcano, but no eruption is imminent. A similar burst of activity prompted a yellow warning in June 2012, but the volcano soon quieted down," LiveScience reported.