Coseismic slip distribution of the February 27, 2010 Mw 8.8 Maule, Chile earthquake

Abstract

[1] Static offsets produced by the February 27, 2010 M w = 8.8 Maule, Chile earthquake as measured by GPS and InSAR constrain coseismic slip along a section of the Andean megathrust of dimensions 650 km (in length) × 180 km (in width). GPS data have been collected from both campaign and continuous sites sampling both the near-field and far field. ALOS/PALSAR data from several ascending and descending tracks constrain the near-field crustal deformation. Inversions of the geodetic data for distributed slip on the megathrust reveal a pronounced slip maximum of order 15 m at ∼15-25 km depth on the megathrust offshore Lloca, indicating that seismic slip was greatest north of the epicenter of the bilaterally propagating rupture. A secondary slip maximum appears at depth ∼25 km on the megathrust just west of Concepción. Coseismic slip is negligible below 35 km depth. Estimates of the seismic moment based on different datasets and modeling approaches vary from 1.8 to 2.6 × 10 22 N m. Our study is the first to model the static displacement field using a layered spherical Earth model, allowing us to incorporate both near-field and far-field static displacements in a consistent manner. The obtained seismic moment of 1.97 × 10 22 N m, corresponding to a moment magnitude of 8.8, is similar to that obtained by previous seismic and geodetic inversions.

Static slip model of the M w 9.0 Tohoku (Japan) earthquake: Results from joint inversion of terrestrial GPS data and seafloor GPS/acoustic data

“…However, the half-space model overestimates the far-field displacements systematically from the residual distribution ( Figure 6(b)). This drawback of the half-space model was also found by Pollitz et al [19]. As the layered earth model is closer to the real earth structure, we argue that the slip distribution derived from the layered model should be more reasonable.…”

Cambios en el relieve generados como consecuencia del terremoto Mw = 8,8 del 27 de febrero de 2010 en el centro-sur de Chile

“…En la segunda aspereza en el plano de subducción, aproximadamente a los 35,4º S, se inició la ruptura del segmento norte que se propagó hacia el norte, la cual comenzó en un lapso cercano a un minuto respecto a la primera ruptura . Para el segmento norte se determinó un deslizamiento máximo de 16-21m (Lay, 2011;Delouis et al, 2010;Tong et al, 2010;Lorito et al, 2011;Pollitz et al, 2011). Para el segmento sur se determinó un deslizamiento máximo de 9-13 m (Lay, 2011;Delouis et al, 2010;Pollitz et al, 2011;Lorito et al, 2011).…”

Efectos geomorfológicos del tsunami de Chile de 2010 frente a la zona de máximo slip, revelados por imágenes satelitales y observaciones de campo: El caso del litoral arenoso La Trinchera, Región del Maule

“…A pesar de que el slip promedio para el evento ha sido estimado en ~7 m, se han inferido parches o concentraciones locales de slip sobre los 15 m cercanos a la latitud 35°S (Fig. 1b) (MORENO et al 2010;POLLITZ et al 2011;VIGNY et al 2011).…”