A powerful 6.9 magnitude earthquake today struck off the coast of Mexico's Baja California peninsula, experts from the US Geological Survey said. The quake struck at 11:53 am (1753 GMT) at a depth of 10 kilometers, the USGS said. The epicenter was in the Sea of Cortez between the coast of the Mexican mainland and the southern end of the Baja peninsula, 105 kilometers south of the city of Los Mochis and 140 kilometers north-east of La Paz, Baja California, the USGS said. A series of at least seven earthquakes rattled northern Mexico overnight Tuesday into Wednesday, ranging in magnitude from 3.3 to 5.8, the US Geological Survey said.