Real-time automatic uncertainty estimation of coseismic single rectangular fault model using GNSS data

被引：13

作者：

Ohno, Keitaro ^{[1
]}

Ohta, Yusaku ^{[1
,2
,3
]}

Kawamoto, Satoshi ^{[4
]}

Abe, Satoshi ^{[4
]}

Hino, Ryota ^{[1
,3
]}

Koshimura, Shunichi ^{[3
]}

Musa, Akihiro ^{[5
,6
]}

Kobayashi, Hiroaki ^{[7
]}

机构：

[1] Tohoku Univ, Grad Sch Sci, Res Ctr Predict Earthquakes & Volcan Erupt, Aoba Ku, 6-6 Aza Aoba, Sendai, Miyagi 9808578, Japan

[2] Tohoku Univ, Div Estab Frontier Sci Org Adv Studies, Sendai, Miyagi, Japan

[3] Tohoku Univ, Int Res Inst Disaster Sci, Sendai, Miyagi, Japan

[4] Geospatial Informat Author Japan, Tsukuba, Ibaraki, Japan

[5] Tohoku Univ, Cybersci Ctr, Sendai, Miyagi, Japan

[6] NEC Corp Ltd, Tokyo, Japan

[7] Tohoku Univ, Grad Sch Informat Sci, Comp Architecture Lab, Sendai, Miyagi, Japan

来源：

EARTH PLANETS AND SPACE | 2021年 / 73卷 / 01期

基金：

日本学术振兴会;

关键词：

Global Navigation Satellite System (GNSS); Real-time GNSS; Bayesian inversion; Uncertainties estimation; MCMC; REGARD; OFFSHORE TSUNAMI DATA; EARTHQUAKE; GPS; DEFORMATION; INVERSION; SYSTEM; WAVE; OKI;

D O I：

10.1186/s40623-021-01425-0

中图分类号：

P [天文学、地球科学];

学科分类号：

07 ;

摘要：

Rapid estimation of the coseismic fault model for medium-to-large-sized earthquakes is key for disaster response. To estimate the coseismic fault model for large earthquakes, the Geospatial Information Authority of Japan and Tohoku University have jointly developed a real-time GEONET analysis system for rapid deformation monitoring (REGARD). REGARD can estimate the single rectangular fault model and slip distribution along the assumed plate interface. The single rectangular fault model is useful as a first-order approximation of a medium-to-large earthquake. However, in its estimation, it is difficult to obtain accurate results for model parameters due to the strong effect of initial values. To solve this problem, this study proposes a new method to estimate the coseismic fault model and model uncertainties in real time based on the Bayesian inversion approach using the Markov Chain Monte Carlo (MCMC) method. The MCMC approach is computationally expensive and hyperparameters should be defined in advance via trial and error. The sampling efficiency was improved using a parallel tempering method, and an automatic definition method for hyperparameters was developed for real-time use. The calculation time was within 30 s for 1 x 10(6) samples using a typical single LINUX server, which can implement real-time analysis, similar to REGARD. The reliability of the developed method was evaluated using data from recent earthquakes (2016 Kumamoto and 2019 Yamagata-Oki earthquakes). Simulations of the earthquakes in the Sea of Japan were also conducted exhaustively. The results showed an advantage over the maximum likelihood approach with a priori information, which has initial value dependence in nonlinear problems. In terms of application to data with a small signal-to-noise ratio, the results suggest the possibility of using several conjugate fault models. There is a tradeoff between the fault area and slip amount, especially for offshore earthquakes, which means that quantification of the uncertainty enables us to evaluate the reliability of the fault model estimation results in real time.

引用

页数：18