After 137 years without a great earthquake, the Mw 8.1 Pisagua event of 1 April 2014 occurred in the central portion of the southern Peru–northern Chile subduction zone. This megathrust earthquake was preceded by more than 2 weeks of foreshock activity migrating ∼3.5 km/ day toward the mainshock hypocenter. This foreshock sequence was triggered by an Mw 6.7 earthquake on a reverse fault in the upper plate that strikes at a high angle to the trench, similar to well-documented reverse faults onshore. These margin-oblique reverse faults accommodate north-south shortening resulting from subduction across a plate boundary that is curved in map view. Reverse slip on the crustal fault unclamped the subduction interface, precipitating the subsequent megathrust foreshock activity that culminated in the great Pisagua earthquake. The combination of crustal reverse faults and a curved subduction margin also occurs in Cascadia and northeastern Japan, indicating that there are two additional localities where great megathrust earthquakes may be triggered by upper plate fault activity.
Artículos científicos
Upper plate reverse fault reactivation and the unclamping of the megathrust during the 2014 northern Chile earthquake sequence
Abstract
- Revista
- Geology
- Área de investigación
- Identificación de Amenazas
- Autores
- Gabriel González · Pablo Salazar · Felipe Aron · Mahesh Shrivastava
- Temáticas
- Terremotos
- Año
- 2015
Relacionados
Ver todas →Artículos científicos
Vertical evacuation buildings: Sequential earthquake and tsunami assestment
Temáticas: Terremotos • Tsunamis
Artículos científicos
Variable Route Expiration Time based on a Fixed Probability of Failure for Ad-Hoc Networks Routing Applications
Temáticas: Procesos de evacuación