Evidencias morfotectónicas de actividad reciente de la zona de falla de El Salvador en el segmento Ilopango-San Vicente.

Abstract

El Salvador Fault Zone is one of the main strike-slip structures of the Central American volcanic arc. The February 2001 earthquake took place in the Ilopango – San Vicente segment of this fault zone. In this work we show new morphotectonical evidences, that support the hypothesis that this segment is highly active, and accommodates an important amount of deformation. The pattern of the fluvial network, and the features that the Jiboa river shows along its trace, allows us to estimate minimum accommodated dipslip and strike-slip motions. The amounts estimated are 100 m and 1500 m respectively for dip-slip and strike-slip, which confirms that the characteristic event type for this fault is an strike-slip event with a little proportion of dip-slip. Precise datations are needed in order to obtain better seismic hazard assesses for this zone.