Tectonic Plates and Faults - Earthquake Engineering for Structural Design - page 172

172 Earthquake Engineering for Structural Design

Figure 5.30 Circum-Pacific ring (USGS, nd)

Californian segment is dominated by the San Andreas Fault and its
ramifications. This fault forms a 1200km long boundary between the enormous
tectonic plates of the Pacific and the North American. The Pacific plate slips in a
Northwest direction with a rate higher than that of the North American plate,
resulting in a transverse boundary. The rupture is located in the crust at 15-20 km.
The South part is situated in the region of Los Angeles, where a diffuse network of
faults exists.
Mexican segment is divided in two parts. In the North part, a subduction
between the Pacific and the North plates occurs, while in the South, the most active
part is due to the subduction of the Cocos plate under the North American plate.
Central American segment is dominated by the differences in movements
between the North American, the Cocos, the South American and the Caribbean
plates. The subduction fault between the Caribbean and the North American plates
dominates the Northern boundary. The continental segments refer to Venezuela