scholarly journals Fluid Distribution in the Central Andes Subduction Zone Imaged With Magnetotellurics

2019 ◽  
Vol 124 (4) ◽  
pp. 4017-4034 ◽  
Author(s):  
J. Araya Vargas ◽  
N. M. Meqbel ◽  
O. Ritter ◽  
H. Brasse ◽  
U. Weckmann ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Central Andes ◽  
Fluid Distribution

scholarly journals Plate Coupling Mechanism of the Central Andes Subduction: Insight from Gravity Model

2019 ◽  
Vol 9 (1) ◽  
pp. 13-21
Author(s):  
Rezene Mahatsente
Keyword(s):  
Subduction Zone ◽  
Continental Crust ◽  
Gravity Model ◽  
Central Andes ◽  
High Density ◽  
Seismic Gap ◽  
Coupling Mechanism ◽  
Crust And Upper Mantle ◽  
Velocity Models ◽  
Plate Coupling

Abstract The Central Andes experienced major earthquake (Mw =8.2) in April 2014 in a region where the giant 1877 earthquake (Mw=8.8) occurred. The 2014 Iquique earthquake did not break the entire seismic gap zones as previously predicted. Geodetic and seismological observations indicate a highly coupled plate interface. To assess the locking mechanism of plate interfaces beneath Central Andes, a 2.5-D gravity model of the crust and upper mantle structure of the central segment of the subduction zone was developed based on terrestrial and satellite gravity data from the LAGEOS, GRACE and GOCE satellite missions. The densities and major structures of the gravity model are constrained by velocity models from receiver function and seismic tomography. The gravity model defined details of crustal and slab structure necessary to understand the cause of megathrust asperity generation. The densities of the upper and lower crust in the fore-arc (2970 – 3000 kg m−3) are much higher than the average density of continental crust. The high density bodies are interpreted as plutonic or ophiolitic structures emplaced onto continental crust. The plutonic or ophiolitic structures may be exerting pressure on the Nazca slab and lock the plate interfaces beneath the Central Andes subduction zone. Thus, normal pressure exerted by high density fore-arc structures and buoyancy force may control plate coupling in the Central Andes. However, this interpretation does not exclude other possible factors controlling plate coupling in the Central Andes. Seafloor roughness and variations in pore-fluid pressure in sediments along subduction channel can affect plate coupling and asperity generation.

scholarly journals S wave attenuation structure on the western side of the Nankai subduction zone: Implications for fluid distribution and dynamics

2014 ◽  
Vol 119 (10) ◽  
pp. 7805-7822 ◽  
Author(s):  
Tsutomu Takahashi ◽  
Koichiro Obana ◽  
Yojiro Yamamoto ◽  
Ayako Nakanishi ◽  
Shuichi Kodaira ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Wave Attenuation ◽  
Fluid Distribution ◽  
S Wave ◽  
Nankai Subduction Zone ◽  
Attenuation Structure ◽  
Western Side

Seismic imaging of a megathrust splay fault in the North Chilean subduction zone (Central Andes)

2016 ◽  
Vol 689 ◽  
pp. 157-166 ◽  
Author(s):  
Ina Storch ◽  
Stefan Buske ◽  
Cedric Schmelzbach ◽  
Peter Wigger
Keyword(s):  
Subduction Zone ◽  
Seismic Imaging ◽  
Central Andes ◽  
The North ◽  
Splay Fault

scholarly journals Interseismic coupling and seismic potential along the Central Andes subduction zone

2011 ◽  
Vol 116 (B12) ◽  
Author(s):  
Mohamed Chlieh ◽  
Hugo Perfettini ◽  
Hernando Tavera ◽  
Jean-Philippe Avouac ◽  
Dominique Remy ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Central Andes ◽  
Seismic Potential ◽  
Interseismic Coupling

scholarly journals Controls of the lithospheric thermal field of an ocean-continent subduction zone: the southern Central Andes

2021 ◽  
Author(s):  
Constanz Rodriguez Piceda ◽  
Magdalena Scheck-Wenderoth ◽  
Bott Judith ◽  
Maria Laura Gómez Dacal ◽  
Mauro Cacace ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Thermal Field ◽  
Thermal State ◽  
Flow Distribution ◽  
Central Andes ◽  
S Wave ◽  
Southern Central ◽  
Wave Tomography ◽  
Dip Angle ◽  
Oceanic Slab

In an ocean-continent subduction zone, the assessment of the lithospheric thermal state is essential to determine the controls of the deformation within the upper plate and the dip angle of the subducting lithosphere. In this study, we evaluate the degree of influence of both the configuration of the upper plate and variations of the subduction angle on the lithospheric thermal field of the southern Central Andes (29°–39°S). Here, the subduction angle increases from subhorizontal (5°) north of 33°S, to steep (~30°) in the south. We derived the 3D temperature and heat flow distribution of the lithosphere in the southern Central Andes considering conversion of S wave tomography to temperatures together with steady-state conductive modeling. We found that the orogen is overall warmer than the forearc and the foreland, and that the lithosphere of the northern part of the foreland appears colder than its southern counterpart. Sedimentary blanketing and the thickness of the radiogenic crust exert the main control on the shallow thermal field (< 50 km depth). Specific conditions are present where the oceanic slab is relatively shallow (< 85 km depth) and the radiogenic crust is thin, This configuration results in relatively colder temperatures compared to regions where the radiogenic crust is thick and the slab is steep. At depths >50 km, the temperatures of the overriding plate are mainly controlled by the mantle heat input and the subduction angle. The thermal field of the upper plate likely preserves the flat subduction angle and influences the spatial distribution of shortening.

Sign in / Sign up

Export Citation Format

Share Document