On Friday 29 March 2013, slightly after 5.00 pm GMT, the United States Geological Survey recorded a Magnitude 4.6 Earthquake at a depth of 17.3 km, roughly 30 km southwest of El Hierro in the Canary Islands. This is a moderately large Earthquake, but is unlikely to have been felt this far offshore.
The Canary Islands are a group of volcanic islands fueled by a mantle plume rising through the African Plate, on which they are situated. The plume is rising from deep within the Earth, and is independent of the movement of the tectonic plates at the Earth's surface. As the plate moves relative to the hotspot new volcanic islands form on its surface, each over the hotspot when it forms, with the oldest islands of the chain in the east (the African Plate is being pushed east by the expansion of the Atlantic Ocean, but the hotspot is relatively motionless). Earthquake activity to the south of El Hierro began in July 2011, since when there has been considerably activity including a number of volcanic eruptions. In December 2011 it was confirmed that a new volcanic fissure had opened up beneath the sea to the south of El Hierro, and a new volcanic island is apparently in the process of being born.
See also Fresh volcanic activity on El Hierro, Ongoing volcanic activity on El Hierro in the Canary Islands, Tourists evacuated due to volcanic activity on El Hierro in the Canary Islands and Volcanoes and Earthquakes on Sciency Thoughts YouTube.
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