IDEAN   23403
INSTITUTO DE ESTUDIOS ANDINOS "DON PABLO GROEBER"
Unidad Ejecutora - UE
capítulos de libros
Título:
The Peru-Chile margin from global gravity field derivatives.
Autor/es:
ORLANDO ALVAREZ; ANDRES FOLGUERA; MARIO GIMENEZ; LINCE KLINGER, F
Libro:
The evolution of the Chilean-Argentinean Andes
Editorial:
Springer
Referencias:
Año: 2018; p. 59 - 79
Resumen:
Deformation along the 3,500 km subduction Pacific margin of the6 Peru-Chile trench is partially controlled by ocean bathymetric heterogeneities and7 sediments. Oceanic highs (e.g. ridges, fracture zones, plateaus) influence defor-8 mation in the fore-arc zone where collision occurs, and control turbiditic flow9 dispersal and consequently the amount of sediments accreted at the frontal accre-10 tionary prism and subduction channel, compartmentalizing the trench into segments11 linked to seismic segmentation. Recent satellite missions (CHAMP, GRACE and12 GOCE) have introduced an extraordinary improvement in the reconstruction of the13 global gravity field. Earth gravity field models, mainly derived from satellite14 measurements, reflect mass inhomogeneities of the earth. This chapter focuses on15 the determination of mass heterogeneities over the oceanic plate and their relation to16 general distribution of sediments over the Peru-Chilean margin, seismic segmen-17 tation along the margin, and the relationship between trench sediment thickness and18 the variable Andean orogenic volume, by means of a gravimetric analysis. Using19 the gravity potential model EGM2008 and satellite GOCE data we calculated two20 functionals of the geopotential: the Bouguer anomaly and the vertical gravity21 gradient, both corrected for the topographic effect. The vertical gravity gradient22 field is of special interest as it highlights main geological features, and allows23 unraveling unknown structures that are concealed by sediments. From these, dif-24 ferent features can be clearly depicted such as the contact between the Pacific