According to Involcan, the Volcanological Institute of the Canaries, over 550 earthquakes were reported and monitored between Monday and Christmas Day on Wednesday.
Some 30 of these were said to have been a 3-magnitude quake or higher.
The majority of these quakes, as well as the swelling on El Hierro, were centered on the region of La Restinga on the south coast of the island.
The 5.1-magnitude quake was the strongest ever recorded in the region and its epicenter was said to be around nine miles deep.
