A relatively mild earthquake of 4.3 magnitude with a center 184 km from Cabo San Lucas, Baja California
Sur, Mexico shook the area Tuesday Dec 2nd at 1:51PM
The event was mild by earthquake standards and no tsunami
statement was issued.
The quake was at 10 km depth in the Pacific Ocean to the south
of the resort.
Los Cabos has a history of earthquakes, some of them
relatively severe, with one actually occurring in the middle of Hurricane
Odile.
The reason for this is that the Baja California peninsula
was once a part of the North American Plate, the tectonic plate of which
mainland Mexico remains a part. About 12 to 15 million years ago the East
Pacific Rise began cutting into the margin of the North American Plate,
initiating the separation of the peninsula from it. Spreading within the Gulf
of California there are short oblique rifts or ridge segments connected by
long northwest trending transform faults, which together comprise the Gulf of
California Rift Zone.
The north end of the rift zone is located in the Brawley
seismic zone in the Salton Sea basin between the Cerro Prieto Fault and the San
Andreas Fault.
The Baja California peninsula is now part of the Pacific Plate
and is moving with it away from the East Pacific Rise in a north northwestward
direction and it is this pressure and tension which gives rise to the earthquakes in the area from time to time.
