Aftershocks following the 2011 Tohoku-Oki earthquake driven by both stress transfer and afterslip

Progress in Earth and Planetary Science

Research Article

Taku Ueda¹  Aitaro Kato² 

[1] Disaster Prevention Research Institute, Kyoto University, 611-0011, Gokasho, Uji, Kyoto, Japan;Earthquake Research Institute, The University of Tokyo, 1-1-1 Yayoi, 113-0032, Bunkyo-Ku, Tokyo, Japan;

关键词: Aftershock;    Stress transfer;    Afterslip;    2011 Tohoku-Oki earthquake;    HIST-ETAS model;    Background earthquakes;    Triggered earthquakes;   

DOI  :  10.1186/s40645-023-00564-0

 received in 2023-02-11, accepted in 2023-06-14,  发布年份 2023

来源: Springer

【 摘 要 】

Aftershocks are a fundamental characteristic of seismicity, and their generation mechanism is mainly characterized by two physical models, stress transfer from large earthquakes and afterslip-induced stress loading. However, the contribution of each mechanism to aftershock generation remains unclear. Here we investigate the spatiotemporal variations in aftershock activity following the 2011 Tohoku-Oki earthquake by applying the Hierarchical Space–Time Epidemic-Type Aftershock Sequence (HIST-ETAS) model to the decade of recorded seismicity since the mainshock. Using the estimated HIST-ETAS model, we categorize the aftershocks into background earthquakes (which are caused by aseismic phenomena) and triggered earthquakes (which are caused by earthquake-to-earthquake interactions). Most of the earthquakes that occurred updip of the large coseismic slip zone along the Japan Trench are triggered earthquakes, consistent with the lack of afterslip in this area. Conversely, background earthquakes are the predominant earthquake type in the long-term downdip of the large coseismic slip zone, and they positively correlate with the afterslip evolution. Our results suggest the importance of combining these two end-member aftershock generation models to explain aftershock activity and thus provide new insights into the relationship between afterslip and spatiotemporal aftershock distribution. Our classifications may also contribute to the monitoring of afterslip in a given region that hosts a large earthquake, particularly where geodetic observation networks are too sparse to evaluate afterslip evolution.

【 授权许可】

CC BY   
© The Author(s) 2023

【 图 表 】

Fig. 10

42004_2023_911_Article_IEq60.gif

Fig. 9

Fig. 7

Fig. 6

Fig. 2

Fig. 5

Fig. 9

Fig. 1

42004_2023_911_Article_IEq48.gif

Fig. 5

Fig. 4

Fig. 3

Fig. 2

Fig. 2

Fig. 1

Fig. 5

42004_2023_911_Article_IEq37.gif

Fig. 1

42004_2023_911_Article_IEq042.gif

42004_2023_911_Article_IEq041.gif

42004_2023_911_Article_IEq17.gif

42004_2023_911_Article_IEq16.gif

42004_2023_911_Article_IEq15.gif

Fig. 3

42004_2023_911_Article_IEq13.gif

42004_2023_911_Article_IEq12.gif

42004_2023_911_Article_IEq10.gif

42004_2023_911_Article_IEq8.gif

Fig. 7

Fig. 2

Fig. 1

40854_2023_495_Article_IEq32.gif

Fig. 9

Fig. 1

12302_2023_750_Article_IEq9.gif

12302_2023_750_Article_IEq8.gif

Fig. 4

Fig. 6

Fig. 8

Fig. 2

40854_2023_495_Article_IEq22.gif

Fig. 1

Fig. 10

Fig. 1

12302_2023_750_Article_IEq5.gif

42004_2023_932_Article_IEq5.gif

Fig. 3

Fig. 3

Fig. 7

40538_2023_419_Article_IEq1.gif

Fig. 3

Fig. 2

Fig. 6

Fig. 2

12888_2023_4935_Article_IEq1.gif

Fig. 3

Fig. 5

Fig. 1