Long-Term Seismic Quiescences and Great Earthquakes in and Around the Japan Subduction Zone Between 1975 and 2012

Abstract

Abstract-An earthquake catalog created by the International Seismological Center (ISC) was analyzed, including 3898 earthquakes located in and around Japan between January 1964 and June 2012 shallower than 60 km with the body wave magnitude of 5.0 or larger. Clustered events such as earthquake swarms and aftershocks were removed from the ISC catalog by using a stochastic declustering method based on Epidemic-Type Aftershock Sequence (ETAS) model. A detailed analysis of the earthquake catalog using a simple scanning technique (ZMAP) shows that the long-term seismic quiescences lasting more than 9 years were recognized ten times along the subduction zone in and around Japan. The three seismic quiescences among them were followed by three great earthquakes: the 1994 Hokkaido-toho-oki earthquake (M w 8.3), the 2003 Tokachi-oki earthquake (M w 8.3), and the 2011 Tohoku earthquake (M w 9.0). The remaining seven seismic quiescences were followed by no earthquake with the seismic moment M 0 C 3.0 9 10 21 Nm (M w 8.25), which are candidates of the false alarm. The 2006 Kurile Islands earthquake (M w 8.3) was not preceded by the significant seismic quiescence, which is a case of the surprise occurrence. As a result, when limited to earthquakes with the seismic moment of M 0 C 3.0 9 10 21 Nm, four earthquakes occurred between 1976 and 2012 in and around Japan, and three of them were preceded by the long-term seismic quiescence lasting more than 9 years.

Statistical Analysis of the Preparatory Phase of the Mw 8.1 Iquique Earthquake, Chile

“…Quiescence has been observed many times before large earthquakes (Katsumata, 2018;Ogata, 1992;Wiemer & Wyss, 1994;Wu & Chiao, 2006;Wyss & Habermann, 1988), but the potential mechanisms that are behind it are still poorly understood. It is interesting to observe that the quiescence appears in a region of high coupling coefficient ( Figure 8) (Métois et al, 2016).…”

Tsunami Generation Efficiency of the 1994, 2006 and 2007 Kuril Islands Earthquakes

“…Figure 1 shows the positions of the BPRs that provided the records used in this study for every event. The Shikotan intraplate M w = 8.3 earthquake of 4 October 1994 was one of the strongest in the Kuril Islands area in the last century (Katsumata, 2017;Tanioka et al, 1995). A previous earthquake of similar magnitude occurred in this area only 25 years before (M w = 8.2) but the 11 August 1969 event was of the interplate type (Fukao & Furumoto, 1975;Satake & Tanioka, 1999).…”

Spatio-Temporal Variation Seismicity Pattern in East Java Between 2002 and 2022 Based on the b-value and Seismic Quiescence z-value

“…After 2016, the z-value was decreasing. An increasing seismicity rate during low z-value period was marked by the occurrence of significant earthquakes on 16 November 2016 (5.7 MW), 10 October 2018 (6.0 MW), 16 July 2019 (5.7 MW), 18 March 2020 (6.2 MW), and 10 April 2021 (6.0 MW). Thus, the duration between quiescence in East Java is 7 -8 years.…”

“…The data analyzed also needs to be added over a longer time interval. As a depiction, during 1975 -2012, 3 of 4 large earthquakes that occurred in the Japan subduction zone were preceded by seismic quiescence that lasted more than 9 years [16]. Although this research employed data from the USGS catalog which is a global network, the addition of earthquake data recorded by a local seismic stations network is also required to increase the data reliability.…”

“…The level of decreasing in seismicity rate is expressed by the z-value [12]. Several studies have been conducted on the rate of seismicity in a region, including in Southwestern China [13], Eastern Turkey [14], Sakhalin [15], the Japanese subduction zone [16], and California [10]. These studies show a period of quiescence with a duration of several months to several years before a large earthquake occurs.…”