Rupture area analysis of the Ecuador (Musine) Mw = 7.8 thrust earthquake on April 16, 2016, using GOCE derived gradients

The Ecuador Mw = 7.8 earthquake on April 16, 2016, ruptured a nearly 200 km long zone along the plate interface between Nazca and South American plates which is coincident with a seismic gap since 1942, when a Mw = 7.8 earthquake happened. This earthquake occurred at a margin characterized by modera...

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Autores principales: Álvarez, O., Folguera, A., Gimenez, M.
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_16749847_v8_n1_p49_Alvarez
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spelling todo:paper_16749847_v8_n1_p49_Alvarez2023-10-03T16:29:33Z Rupture area analysis of the Ecuador (Musine) Mw = 7.8 thrust earthquake on April 16, 2016, using GOCE derived gradients Álvarez, O. Folguera, A. Gimenez, M. Ecuador earthquake Gravity field and Ocean Circulation Explorer (GOCE) Rupture zone Trench sediments Vertical gravity gradient Cocos plate earthquake event earthquake rupture GOCE gravity field Nazca plate satellite data seismic zone thrust Andes Costa Rica Ecuador The Ecuador Mw = 7.8 earthquake on April 16, 2016, ruptured a nearly 200 km long zone along the plate interface between Nazca and South American plates which is coincident with a seismic gap since 1942, when a Mw = 7.8 earthquake happened. This earthquake occurred at a margin characterized by moderately big to giant earthquakes such as the 1906 (Mw = 8.8). A heavily sedimented trench explains the abnormal lengths of the rupture zones in this system as inhibits the role of natural barriers on the propagation of rupture zones. High amount of sediment thickness is associated with tropical climates, high erosion rates and eastward Pacific dominant winds that provoke orographic rainfalls over the Pacific slope of the Ecuatorian Andes. Offshore sediment dispersion off the oceanic trench is controlled by a close arrangement of two aseismic ridges that hit the Costa Rica and South Ecuador margin respectively and a mid ocean ridge that separates the Cocos and Nazca plate trapping sediments. Gravity field and Ocean Circulation Explorer (GOCE) satellite data are used in this work to test the possible relationship between gravity signal and earthquake rupture structure as well as registered aftershock seismic activity. Reduced vertical gravity gradient shows a good correlation with rupture structure for certain degrees of the harmonic expansion and related depth of the causative mass; indicating, such as in other analyzed cases along the subduction margin, that fore-arc structure derived from density heterogeneities explains at a certain extent propagation of the rupture zones. In this analysis the rupture zone of the April 2016 Ecuador earthquake developed through a relatively low density zone of the fore-arc sliver. Finally, aftershock sequence nucleated around the area of maximum slips in the rupture zone, suggesting that heterogeneous density structure of the fore-arc determined from gravity data could be used in forecasting potential damaged zones associated with big ruptures along the subduction border. © 2017 Institute of Seismology, China Earthquake Administration Fil:Folguera, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_16749847_v8_n1_p49_Alvarez
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Ecuador earthquake
Gravity field and Ocean Circulation Explorer (GOCE)
Rupture zone
Trench sediments
Vertical gravity gradient
Cocos plate
earthquake event
earthquake rupture
GOCE
gravity field
Nazca plate
satellite data
seismic zone
thrust
Andes
Costa Rica
Ecuador
spellingShingle Ecuador earthquake
Gravity field and Ocean Circulation Explorer (GOCE)
Rupture zone
Trench sediments
Vertical gravity gradient
Cocos plate
earthquake event
earthquake rupture
GOCE
gravity field
Nazca plate
satellite data
seismic zone
thrust
Andes
Costa Rica
Ecuador
Álvarez, O.
Folguera, A.
Gimenez, M.
Rupture area analysis of the Ecuador (Musine) Mw = 7.8 thrust earthquake on April 16, 2016, using GOCE derived gradients
topic_facet Ecuador earthquake
Gravity field and Ocean Circulation Explorer (GOCE)
Rupture zone
Trench sediments
Vertical gravity gradient
Cocos plate
earthquake event
earthquake rupture
GOCE
gravity field
Nazca plate
satellite data
seismic zone
thrust
Andes
Costa Rica
Ecuador
description The Ecuador Mw = 7.8 earthquake on April 16, 2016, ruptured a nearly 200 km long zone along the plate interface between Nazca and South American plates which is coincident with a seismic gap since 1942, when a Mw = 7.8 earthquake happened. This earthquake occurred at a margin characterized by moderately big to giant earthquakes such as the 1906 (Mw = 8.8). A heavily sedimented trench explains the abnormal lengths of the rupture zones in this system as inhibits the role of natural barriers on the propagation of rupture zones. High amount of sediment thickness is associated with tropical climates, high erosion rates and eastward Pacific dominant winds that provoke orographic rainfalls over the Pacific slope of the Ecuatorian Andes. Offshore sediment dispersion off the oceanic trench is controlled by a close arrangement of two aseismic ridges that hit the Costa Rica and South Ecuador margin respectively and a mid ocean ridge that separates the Cocos and Nazca plate trapping sediments. Gravity field and Ocean Circulation Explorer (GOCE) satellite data are used in this work to test the possible relationship between gravity signal and earthquake rupture structure as well as registered aftershock seismic activity. Reduced vertical gravity gradient shows a good correlation with rupture structure for certain degrees of the harmonic expansion and related depth of the causative mass; indicating, such as in other analyzed cases along the subduction margin, that fore-arc structure derived from density heterogeneities explains at a certain extent propagation of the rupture zones. In this analysis the rupture zone of the April 2016 Ecuador earthquake developed through a relatively low density zone of the fore-arc sliver. Finally, aftershock sequence nucleated around the area of maximum slips in the rupture zone, suggesting that heterogeneous density structure of the fore-arc determined from gravity data could be used in forecasting potential damaged zones associated with big ruptures along the subduction border. © 2017 Institute of Seismology, China Earthquake Administration
format JOUR
author Álvarez, O.
Folguera, A.
Gimenez, M.
author_facet Álvarez, O.
Folguera, A.
Gimenez, M.
author_sort Álvarez, O.
title Rupture area analysis of the Ecuador (Musine) Mw = 7.8 thrust earthquake on April 16, 2016, using GOCE derived gradients
title_short Rupture area analysis of the Ecuador (Musine) Mw = 7.8 thrust earthquake on April 16, 2016, using GOCE derived gradients
title_full Rupture area analysis of the Ecuador (Musine) Mw = 7.8 thrust earthquake on April 16, 2016, using GOCE derived gradients
title_fullStr Rupture area analysis of the Ecuador (Musine) Mw = 7.8 thrust earthquake on April 16, 2016, using GOCE derived gradients
title_full_unstemmed Rupture area analysis of the Ecuador (Musine) Mw = 7.8 thrust earthquake on April 16, 2016, using GOCE derived gradients
title_sort rupture area analysis of the ecuador (musine) mw = 7.8 thrust earthquake on april 16, 2016, using goce derived gradients
url http://hdl.handle.net/20.500.12110/paper_16749847_v8_n1_p49_Alvarez
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AT gimenezm ruptureareaanalysisoftheecuadormusinemw78thrustearthquakeonapril162016usinggocederivedgradients
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