Two years after a new underwater volcano appeared offshore of El Hierro in the Canary Islands, earthquake swarms and a sudden change in height suggest a new eruption is brewing near the island’s villages, officials announced today (Dec. 27).

After the announcement, one of the largest temblors ever recorded at the volcanic island, a magnitude-5.1 earthquake, struck offshore of El Hierro at 12:46 p.m. ET (5:46 p.m. local time) today, the National Geographic Institute reported. Residents on the island reported strong shaking, and the quake was felt throughout the Canary Islands, according to news reports. The earthquake’s epicenter was 9 miles (15 kilometers) deep.

Before the earthquake struck early this afternoon, the island’s volcano monitoring agency, Pelvolca, had raised the volcanic eruption risk for El Hierro to “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.

Source: Scientific American – New Eruption May Be Brewing at Volcano in Canary Islands