14 Yrars of instrumental seismicity in ecuador: What have we seen and learned?

Abstract:

With the deployment of the seismic network since 1990, in Ecuador has been identified several focus of seismic activity related with subduction zone, subducted plate and minor and major inland structures. The coastal zone of Ecuador has been affected by several 6.9 and greater subduction earthquakes. Since 1990, they have been noticed seismic swarms which delimited segments along the coast and delimited also the 1998, 6.9 Mw, Bahia Earthquake region, defining patterns like gaps and doughnuts that still limit a zone where it may occur a 7.5 earthquake. Due to two zones that register deep seismicity, it has been possible to imaging of the subducted plate. Below the central coastal zone, the plate is around 120 km depth. Towards the East, below the volcanic arc, the seismicity is diffuse and only in few zones both to the north and the south we have seen deep earthquakes with depths no longer than 140 km. In the eastern region, a seismic nest with important activity, even registered by the worldwide seismic network, has events with depths ranging from 180 to 220 km. Inland, the major activity is related with several earthquakes and the aftershocks in 1995, 1996, with occasional tectonic activity in some structures, and with a seismic swarm -Pisayambo-. Pisayambo's activity represents around the 35% of the activity registered by the National Seismic Network. Also, an important activity related with the volcanic unrest of Guagua. Pichincha Volcano in 1998-1999 and Cotopaxi Volcano in 2001 and 2002 has been noticed.

Año de publicación:

2005

Keywords:

Fuente:

scopus