Modified estimation and forecasting of the hierarchical space-time ETAS (HIST-ETAS) model for earthquake catalogs in a wide area possessing long- and short-term incompleteness

Yosihiko Ogata, & Koichi Katsura

Published August 13, 2021, SCEC Contribution #11394, 2021 SCEC Annual Meeting Poster #253 (PDF)

Poster Image: 
In this study, we use the hierarchical spatio-temporal ETAS (HIST-ETAS) model to make short-term forecasts of region-dependent seismic activity and to separate background seismicity rates over a wide area, such as all of Japan and inland areas. In order to improve the resolution of the forecasts and background seismic rates, the threshold magnitude value of the JMA seismic source catalog can be appropriately lower. However, this requires taking into account the artificial spatio-temporal heterogeneity of the data in the long run. At the same time, a large number of successive aftershocks occur immediately after a major earthquake, resulting in overlapping aftershock waveforms and missing smaller aftershocks. Therefore, by estimating the aftershock detection rates that decreases after large earthquakes, we can re-estimate the unbiased parameters of the HIST-ETAS model. As a result, we can visualize how the seismic activity is corrected after large earthquakes, and predict and animate the spatio-temporal earthquake rates in quasi-real time.

References and Software with Manuals　
1) Ogata, Y. and Katsura, K. (1993). Analysis of temporal and spatial heterogeneity of magnitude frequency distribution inferred from earthquake catalogues, Geophys. J. Int., 113, 727-738.

2) Ogata, Y. and Katsura, K. (2006). Immediate and updated forecasting of aftershock hazard, Geophys. Res. Lett., 33 (10), L10305, doi:10.1029/2006GL025888.

3) Ogata et al. (2021) Hierarchical Space-Time Point-Process Models (HIST-PPM): Software Documentation and codes, Computer Science Monographs https://www.ism.ac.jp/editsec/csm/index_j.html No. 35, The Institute of Statistical Mathematics, Tokyo; or temporally available in http://bemlar.ism.ac.jp/ogata/HIST-PPM-V3/．

Key Words
space-time ETAS model, hypocenter detection rates, 2D and 3D Delaunay tessellation

Citation
Ogata, Y., & Katsura, K. (2021, 08). Modified estimation and forecasting of the hierarchical space-time ETAS (HIST-ETAS) model for earthquake catalogs in a wide area possessing long- and short-term incompleteness. Poster Presentation at 2021 SCEC Annual Meeting.


Related Projects & Working Groups
Earthquake Forecasting and Predictability (EFP)