Analysis of the spatial and temporal distribution of the 2001 earthquakes in El Salvador

Abstract

The earthquake was centered at 12.80° N, 88.79° W with a focal depth of 40 km, in the subduction zone between the Cocos and Caribbean plates. This earthquake was followed by numerous aftershocks with the same origin; ~540 events with M > 2 occurred in the fi rst month, and 4000 in the fi rst six months, nearly half of which were larger than M 3.0. Just one month later, on 13 February, a second major earthquake of M W 6.6 occurred, this time located farther inland Geological Society of America Special Paper 375 2004

Susceptibility assessment of earthquake-triggered landslides in El Salvador using logistic regression

“…The epicentre was located off the western coast of El Salvador, at 12.80°N/88.79°W, in the subduction zone between the Cocos and Caribbean plates, with a magnitude of Mw 7.7 and a focal depth of 40km (Benito et al, 2004). The second destructive earthquake occurred 1 month later on February 13, with a magnitude of Mw 6.6, located further inland near San Pedro Nonualco (30km from San Salvador), and with a shallower focal depth of 15km (Fig.…”

Triggering of destructive earthquakes in El Salvador

“…The fault geometry and slip directions used in the models are derived from the focal mechanisms (Table 1) and from a spatial analysis (see footnote 1) of the aftershocks described in detail in Benito et al (2004). The ruptures were modeled as rectangles with the slip tapered on the rectangular slip patches.…”

“…The possibility that this succession was related to coseismic and postseismic interactions between different earthquakes has been proposed (Parsons, 2002;Benito et al, 2004). The transfer of the Coulomb failure stress (CFS) produced during a main shock is able to induce other main shocks and/or control the location of aftershocks, even at tens of kilometers (King et al, 1994;Harris, 1998;Stein, 1999).…”

GPS-derived coupling estimates for the Central America subduction zone and volcanic arc faults: El Salvador, Honduras and Nicaragua

“…1) and ∼10–15 mm yr −1 of northwestward trench‐parallel motion of areas outboard from the volcanic arc (White 1991; DeMets 2001; Dewey et al 2004; Turner et al 2007). Associated with these processes, destructive volcanic arc earthquakes in El Salvador and Nicaragua have occurred every several years over the past century (White 1991; White & Harlow 1993) and every ∼70 yr offshore along or close to the Cocos Plate subduction interface (Satake 1994; Bommer et al 2002; Benito et al 2004; White et al 2004). These earthquakes have caused nearly 20 000 fatalities in the past century (White & Harlow 1993), underscoring the importance of better understanding their sources and causes.…”