Moderate 5.4 underwater earthquake strikes North Mid-Atlantic Ridge

August 31, 2011 – MAR – A magnitude 5.4 subsea earthquake struck along the Northern Mid-Atlantic Ridge on Wednesday, according to the European-Mediterranean Seismological Centre. The earthquake was recorded at a depth of 10km and was located just over 500 kilometres from the Azores- a magma hotspot. The quake occurred at 1:17 PM GMT. The Mid-Atlantic Ridge (MAR) is a mid-ocean ridge, a divergent tectonic plate boundary located along the floor of the Atlantic Ocean, and part of the longest mountain range in the world. It separates the Eurasian Plate and North American Plate in the North Atlantic, and the African Plate from the South American Plate in the South Atlantic. The Ridge extends from a junction with the Gakkel Ridge (Mid-Arctic Ridge) northeast of Greenland southward to the Bouvet Triple Junction in the South Atlantic. Although the Mid-Atlantic Ridge is mostly an underwater feature, portions of it have enough elevation to extend above sea level. The section of the ridge which includes the island of Iceland is also known as the Reykjanes Ridge. The average spreading rate for the ridge is about 2.5 cm per year. –IWO