Interseismic coupling and asperity distribution along the Kamchatka subduction zone
[1] GPS measurements of interseismic horizontal surface velocities reveal the degree of kinematic coupling of the plate boundary thrust along the Kamchatka subduction zone from about 51 degrees to 57 degrees N latitude. Inversions for the distribution of aseismic slip rate along the similar to 15 de...
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ftcdlib:qt4q38n4x0 2023-05-15T16:58:40+02:00 Interseismic coupling and asperity distribution along the Kamchatka subduction zone Bürgmann, Roland Kogan, M G Steblov, G M Hilley, G Levin, V E Apel, E 1 - 17 2005-07-01 application/pdf http://www.escholarship.org/uc/item/4q38n4x0 english eng eScholarship, University of California qt4q38n4x0 http://www.escholarship.org/uc/item/4q38n4x0 public Bürgmann, Roland; Kogan, M G; Steblov, G M; Hilley, G; Levin, V E; & Apel, E. (2005). Interseismic coupling and asperity distribution along the Kamchatka subduction zone. Journal of Geophysical Research-Solid Earth, 110(B7), 1 - 17. doi:10.1029/2005JB003648. UC Berkeley: Retrieved from: http://www.escholarship.org/uc/item/4q38n4x0 article 2005 ftcdlib https://doi.org/10.1029/2005JB003648 2016-04-02T18:33:13Z [1] GPS measurements of interseismic horizontal surface velocities reveal the degree of kinematic coupling of the plate boundary thrust along the Kamchatka subduction zone from about 51 degrees to 57 degrees N latitude. Inversions for the distribution of aseismic slip rate along the similar to 15 degrees NW dipping underthrust suggest a nonslipping plate interface in southern Kamchatka above similar to 50 km depth, along the segment that ruptured in the M-w = 9, 1952 earthquake. North of similar to 53 degrees N, the subduction interface experiences significant aseismic slip, consistent with the lower seismic moment release in M <= 8.5 earthquakes along this portion of the subduction zone. The GPS velocities are consistent with a boundary element forward model in which historic earthquake rupture zones are represented as locked asperities, surrounded by a zero shear stress subduction interface loaded by plate convergence. Models in which the complete rupture zones of historic earthquakes are considered locked greatly overpredict the degree of kinematic coupling. Reducing the area of the locked model asperities to the central 25% area of historic rupture zones fits the data well, suggesting that large earthquakes involve small fully locked core asperities surrounded by conditionally stable portions of the plate interface. Areas of low aseismic slip rate appear to be roughly correlated with areas of low isostatic gravity anomalies over offshore forearc basins, while less coupled portions of the Kamchatka subduction zone coincide with high-gravity anomalies offshore of two peninsulas, possibly related to the subduction of the Emperor-Meji seamount chain and the Kruzenstern fracture zone. Article in Journal/Newspaper Kamchatka University of California: eScholarship Journal of Geophysical Research 110 B7 |
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Open Polar |
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University of California: eScholarship |
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ftcdlib |
language |
English |
description |
[1] GPS measurements of interseismic horizontal surface velocities reveal the degree of kinematic coupling of the plate boundary thrust along the Kamchatka subduction zone from about 51 degrees to 57 degrees N latitude. Inversions for the distribution of aseismic slip rate along the similar to 15 degrees NW dipping underthrust suggest a nonslipping plate interface in southern Kamchatka above similar to 50 km depth, along the segment that ruptured in the M-w = 9, 1952 earthquake. North of similar to 53 degrees N, the subduction interface experiences significant aseismic slip, consistent with the lower seismic moment release in M <= 8.5 earthquakes along this portion of the subduction zone. The GPS velocities are consistent with a boundary element forward model in which historic earthquake rupture zones are represented as locked asperities, surrounded by a zero shear stress subduction interface loaded by plate convergence. Models in which the complete rupture zones of historic earthquakes are considered locked greatly overpredict the degree of kinematic coupling. Reducing the area of the locked model asperities to the central 25% area of historic rupture zones fits the data well, suggesting that large earthquakes involve small fully locked core asperities surrounded by conditionally stable portions of the plate interface. Areas of low aseismic slip rate appear to be roughly correlated with areas of low isostatic gravity anomalies over offshore forearc basins, while less coupled portions of the Kamchatka subduction zone coincide with high-gravity anomalies offshore of two peninsulas, possibly related to the subduction of the Emperor-Meji seamount chain and the Kruzenstern fracture zone. |
format |
Article in Journal/Newspaper |
author |
Bürgmann, Roland Kogan, M G Steblov, G M Hilley, G Levin, V E Apel, E |
spellingShingle |
Bürgmann, Roland Kogan, M G Steblov, G M Hilley, G Levin, V E Apel, E Interseismic coupling and asperity distribution along the Kamchatka subduction zone |
author_facet |
Bürgmann, Roland Kogan, M G Steblov, G M Hilley, G Levin, V E Apel, E |
author_sort |
Bürgmann, Roland |
title |
Interseismic coupling and asperity distribution along the Kamchatka subduction zone |
title_short |
Interseismic coupling and asperity distribution along the Kamchatka subduction zone |
title_full |
Interseismic coupling and asperity distribution along the Kamchatka subduction zone |
title_fullStr |
Interseismic coupling and asperity distribution along the Kamchatka subduction zone |
title_full_unstemmed |
Interseismic coupling and asperity distribution along the Kamchatka subduction zone |
title_sort |
interseismic coupling and asperity distribution along the kamchatka subduction zone |
publisher |
eScholarship, University of California |
publishDate |
2005 |
url |
http://www.escholarship.org/uc/item/4q38n4x0 |
op_coverage |
1 - 17 |
genre |
Kamchatka |
genre_facet |
Kamchatka |
op_source |
Bürgmann, Roland; Kogan, M G; Steblov, G M; Hilley, G; Levin, V E; & Apel, E. (2005). Interseismic coupling and asperity distribution along the Kamchatka subduction zone. Journal of Geophysical Research-Solid Earth, 110(B7), 1 - 17. doi:10.1029/2005JB003648. UC Berkeley: Retrieved from: http://www.escholarship.org/uc/item/4q38n4x0 |
op_relation |
qt4q38n4x0 http://www.escholarship.org/uc/item/4q38n4x0 |
op_rights |
public |
op_doi |
https://doi.org/10.1029/2005JB003648 |
container_title |
Journal of Geophysical Research |
container_volume |
110 |
container_issue |
B7 |
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1766050742291922944 |