Officials announced on Friday that the recent earthquake swarms and sudden change in height suggest a new eruption is brewing offshore El Hierro in the Canary Islands.

Following the announcement, the volcanic island was struck by a magnitude 5.1 earthquake at 12:46 p.m. ET according to the National Geographic Institute. The quake was felt throughout the Canary Islands.

Before the quake early Friday afternoon, parts of El Hierro had swelled nearly 3 inches in the past week and more than 550 earthquakes rattled the opposite side of the island between Monday and Wednesday. According to the Volcanological Institute of the Canaries (Involcan), the earthquakes are caused by underground magma fracturing rocks and swelling the surface as the hot rock reaches upward.

In 2011, El Hierro was the site of an underwater volcanic eruption that forced residents to evacuate.