scholarly journals Rupture characteristics of the 2005 Tarapaca, northern Chile, intermediate-depth earthquake: Evidence for heterogeneous fluid distribution across the subducting oceanic plate?

2010 ◽  
Vol 115 (B9) ◽  
Author(s):  
Keiko Kuge ◽  
Yuko Kase ◽  
Yumi Urata ◽  
Jaime Campos ◽  
Andriana Perez
Keyword(s):  
Fluid Distribution ◽  
Northern Chile ◽  
Oceanic Plate ◽  
Intermediate Depth ◽  
Intermediate Depth Earthquake

Tectonic regimes and stress patterns in the Vrancea Seismic Zone: Insights into intermediate-depth earthquake nests in locked collisional settings

2021 ◽  
Vol 799 ◽  
pp. 228688
Author(s):  
Laura Petrescu ◽  
Felix Borleanu ◽  
Mircea Radulian ◽  
Alik Ismail-Zadeh ◽  
Liviu Maţenco
Keyword(s):  
Seismic Zone ◽  
Intermediate Depth ◽  
Stress Patterns ◽  
Intermediate Depth Earthquake

Earthquake nests as natural laboratories for the study of intermediate-depth earthquake mechanics

2012 ◽  
Vol 570-571 ◽  
pp. 42-56 ◽  
Author(s):  
Germán A. Prieto ◽  
Gregory C. Beroza ◽  
Sarah A. Barrett ◽  
Gabriel A. López ◽  
Manuel Florez
Keyword(s):  
Intermediate Depth ◽  
Earthquake Mechanics ◽  
Intermediate Depth Earthquake

Structural evidence of the evolution of fore-arc basins off South America

1977 ◽  
Vol 14 (1) ◽  
pp. 102-116 ◽  
Author(s):  
W. T. Coulbourn ◽  
R. Moberly
Keyword(s):  
South America ◽  
Cross Sections ◽  
Seismic Reflection ◽  
Northern Chile ◽  
Oceanic Plate ◽  
Irregular Structure ◽  
Continental Block ◽  
The Face ◽  
Sediment Cover ◽  
Seismic Reflection Profiles

The continental margin of southern Peru and northern Chile was surveyed during the 1973 and 1974 expeditions of the research vessel Kana Keoki. Seismic reflection profiles reveal three large basins at about 1000 m depth between Mollendo, Peru (17°00′ S) and Iquique, Chile (20°00′ S). Only small basins and discontinuous terraces are seen on profiles crossing the Iquique-to-Antofagasta, Chile (23°30′ S) segment of the continental margin.The structural cross-sections of the basins resemble those of arc-trench gaps. The undeformed uppermost reflectors probably represent turbidites, as evidenced by displaced shallow-water benthic foraminifera and coarse sands in cores. Deeper reflectors are generally inclined land-ward, with dips and deformation increasing in the lower reflectors down to about 1.5 seconds penetration. Seaward convergence of these reflectors indicates a progressive shoreward migration of the axis of maximum sedimentation. If the deeper beds are also turbidites, this axis marks the axis of the sediment trap on the continental slope.The structure is consistent with subduction of an oceanic plate and obduction of a portion of its sediment cover. The imbricate stacking of obducted material is lifting an anticlinal ridge visible in most traverses across the trench side of the basin. The growing ridge is deforming the older sediment trapped in the upperslope basin and shifting the locus of deposition shoreward. The irregular distribution of the basins apparently is a product of culminations and depressions of the surfaces of imbricate fault planes. These undulations may result from the transference of the irregular structure of the oceanic plate to the face of the continental block.

Aftershock Activity at Intermediate-Depth Earthquakes in Northern Chile Controlled by Plate Hydration

2020 ◽  
Author(s):  
Leoncio Cabrera ◽  
Sergio Ruiz ◽  
Piero Poli ◽  
Eduardo Contreras-Reyes ◽  
Renzo Mancini ◽  
...  
Keyword(s):  
Template Matching ◽  
Broad Band ◽  
Strong Motion ◽  
Seismic Source ◽  
Northern Chile ◽  
Aftershock Activity ◽  
Study Region ◽  
Abrupt Decrease ◽  
Intermediate Depth ◽  
The Impact

<p>We investigate the differences of the seismic source and aftershock activity using kinematic inversions and template matching respectively, for the six largest intraslab intermediate-depth earthquakes occurred in northern Chile (Mw ~6.3) since 2010 at depths between 90 and 130 km and recorded by dense strong-motion and broad-band seismic networks. In addition, we developed a thermal model using the finite element method in the study region with the aim of analyze the impact of temperature on seismic behavior as the oceanic plate subducts. Our results show that geometries of rupture zones are similar, with semi-axis for an elliptical patch approach about 5 km, and stress drop values between 7 and 30 MPa. On the other hand, the number of aftershocks exhibits clear differences, and their amount decreases with increasing the depth within the slab bounded by the 450 ºC isotherm, which represents a limit between a high-hydrated and a dry or low-hydrated region. Furthermore, mainshocks occur at distances from the top of the slab from 7 to 40 km, and all of them exhibit normal focal mechanisms suggesting that the extensional regimen deepens within the slab to the 700-750 ºC isotherm-depth. We suggest that in northern Chile the abrupt decrease of aftershocks in the lower part of the extensional regimen is caused by the absence of a hydrated slab at those depths.</p>

Intermediate-depth earthquake faulting by dehydration embrittlement with negative volume change

Nature ◽  
2004 ◽  
Vol 428 (6982) ◽  
pp. 545-549 ◽  
Author(s):  
Haemyeong Jung ◽  
Harry W. Green II ◽  
Larissa F. Dobrzhinetskaya
Keyword(s):  
Volume Change ◽  
Intermediate Depth ◽  
Earthquake Faulting ◽  
Intermediate Depth Earthquake ◽  
Negative Volume
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