scholarly journals Along‐Strike Variation and Migration of Long‐Term Slow Slip Events in the Western Nankai Subduction Zone, Japan

2019 ◽  
Vol 124 (4) ◽  
pp. 3853-3880 ◽  
Author(s):  
Ryota Takagi ◽  
Naoki Uchida ◽  
Kazushige Obara
Keyword(s):  
Subduction Zone ◽  
Slow Slip ◽  
Slow Slip Events ◽  
Nankai Subduction Zone ◽  
And Migration

scholarly journals Detection of deep low-frequency earthquakes in the Nankai subduction zone over 11 years using a matched filter technique

2020 ◽  
Author(s):  
Aitaro Kato ◽  
Shigeki Nakagawa
Keyword(s):  
Subduction Zone ◽  
Matched Filter ◽  
Low Frequency ◽  
Slow Slip ◽  
Slow Slip Events ◽  
Filter Technique ◽  
Episodic Tremor And Slip ◽  
Nankai Subduction Zone ◽  
Spatio Temporal

Abstract To improve our understanding of the long-term behavior of low-frequency earthquakes (LFEs) along the tremor belt of the Nankai subduction zone, we applied a matched filter technique to continuous seismic data recorded by a dense and highly sensitive seismic network over an 11 year window, April 2004 to August 2015. We detected a total of ~510,000 LFEs, or ~23× the number of LFEs in the JMA catalog for the same period. During long-term slow slip events (SSEs) in the Bungo Channel, a series of migrating LFE bursts intermittently occurred along the fault-strike direction, with slow hypocenter propagation. Elastic energy released by long-term SSEs appears to control the extent of LFE activity. We identify slowly migrating fronts of LFEs during major episodic tremor and slip (ETS) events, which extend over distances of up to 100 km and follow diffusion-like patterns of spatial evolution with a diffusion coefficient of ~10 4 m 2 /s. This migration pattern closely matches the spatio-temporal evolution of tectonic tremors reported by previous studies. At shorter distances, up to 15 km, we discovered rapid diffusion-like migration of LFEs with a coefficient of ~10 5 m 2 /s. We also recognize that rapid migration of LFEs occurred intermittently in many streaks during major ETS episodes. These observations suggest that slow slip transients contain a multitude of smaller, temporally clustered fault slip events whose evolution is controlled by a diffusional process.

scholarly journals Detection of deep low-frequency earthquakes in the Nankai subduction zone over 11 years using a matched filter technique

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Aitaro Kato ◽  
Shigeki Nakagawa
Keyword(s):  
Subduction Zone ◽  
Matched Filter ◽  
Low Frequency ◽  
Slow Slip ◽  
Slow Slip Events ◽  
Filter Technique ◽  
Episodic Tremor And Slip ◽  
Nankai Subduction Zone ◽  
Spatio Temporal

Abstract To improve our understanding of the long-term behavior of low-frequency earthquakes (LFEs) along the tremor belt of the Nankai subduction zone, we applied a matched filter technique to continuous seismic data recorded by a dense and highly sensitive seismic network over an 11-year window, April 2004 to August 2015. We detected a total of ~ 510,000 LFEs, or ~ 23 × the number of LFEs in the JMA catalog for the same period. During long-term slow slip events (SSEs) in the Bungo Channel, a series of migrating LFE bursts intermittently occurred along the fault-strike direction, with slow hypocenter propagation. Elastic energy released by long-term SSEs appears to control the extent of LFE activity. We identify slowly migrating fronts of LFEs during major episodic tremor and slip (ETS) events, which extend over distances of up to 100 km and follow diffusion-like patterns of spatial evolution with a diffusion coefficient of ~ 104 m2/s. This migration pattern closely matches the spatio-temporal evolution of tectonic tremors reported by previous studies. At shorter distances, up to 15 km, we discovered rapid diffusion-like migration of LFEs with a coefficient of ~ 105 m2/s. We also recognize that rapid migration of LFEs occurred intermittently in many streaks during major ETS episodes. These observations suggest that slow slip transients contain a multitude of smaller, temporally clustered fault slip events whose evolution is controlled by a diffusional process.

scholarly journals Detection of deep low-frequency earthquakes in the Nankai subduction zone over 11 years using a matched filter technique

2020 ◽  
Author(s):  
Aitaro Kato ◽  
Shigeki Nakagawa
Keyword(s):  
Subduction Zone ◽  
Matched Filter ◽  
Low Frequency ◽  
Slow Slip ◽  
Slow Slip Events ◽  
Filter Technique ◽  
Episodic Tremor And Slip ◽  
Nankai Subduction Zone ◽  
Spatio Temporal

Abstract To improve our understanding of the long-term behavior of low-frequency earthquakes (LFEs) along the tremor belt of the Nankai subduction zone, we applied a matched filter technique to continuous seismic data recorded by a dense and highly sensitive seismic network over an 11 year window, April 2004 to August 2015. We detected a total of ~510,000 LFEs, or ~23× the number of LFEs in the JMA catalog for the same period. During long-term slow slip events (SSEs) in the Bungo Channel, a series of migrating LFE bursts intermittently occurred along the fault-strike direction, with slow hypocenter propagation. Elastic energy released by long-term SSEs appears to control the extent of LFE activity. We identify slowly migrating fronts of LFEs during major episodic tremor and slip (ETS) events, which extend over distances of up to 100 km and follow diffusion-like patterns of spatial evolution with a diffusion coefficient of ~10 4 m 2 /s. This migration pattern closely matches the spatio-temporal evolution of tectonic tremors reported by previous studies. At shorter distances, up to 15 km, we discovered rapid diffusion-like migration of LFEs with a coefficient of ~10 5 m 2 /s. We also recognize that rapid migration of LFEs occurred intermittently in many streaks during major ETS episodes. These observations suggest that slow slip transients contain a multitude of smaller, temporally clustered fault slip events whose evolution is controlled by a diffusional process.

scholarly journals Automated detection of slow slip events within the Nankai subduction zone

2011 ◽  
Vol 38 (1) ◽  
pp. n/a-n/a ◽  
Author(s):  
Takeshi Kimura ◽  
Kazushige Obara ◽  
Hisanori Kimura ◽  
Hitoshi Hirose
Keyword(s):  
Subduction Zone ◽  
Automated Detection ◽  
Slow Slip ◽  
Slow Slip Events ◽  
Nankai Subduction Zone

scholarly journals Shallow very-low-frequency earthquakes accompany slow slip events in the Nankai subduction zone

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Masaru Nakano ◽  
Takane Hori ◽  
Eiichiro Araki ◽  
Shuichi Kodaira ◽  
Satoshi Ide
Keyword(s):  
Subduction Zone ◽  
Low Frequency ◽  
Slow Slip ◽  
Slow Slip Events ◽  
Very Low Frequency ◽  
Nankai Subduction Zone

Possible shallow slow slip events in Hyuga-nada, Nankai subduction zone, inferred from migration of very low frequency earthquakes

2015 ◽  
Vol 42 (2) ◽  
pp. 331-338 ◽  
Author(s):  
Youichi Asano ◽  
Kazushige Obara ◽  
Takanori Matsuzawa ◽  
Hitoshi Hirose ◽  
Yoshihiro Ito
Keyword(s):  
Subduction Zone ◽  
Low Frequency ◽  
Slow Slip ◽  
Slow Slip Events ◽  
Very Low Frequency ◽  
Nankai Subduction Zone
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