Significant improvements of the space-time ETAS model for forecasting of accurate baseline seismicity

Abstract

The space-time version of the epidemic type aftershock sequence (ETAS) model is based on the empirical laws for aftershocks, and constructed with a certain space-time function for earthquake clustering. For more accurate seismic prediction, we modify it to deal with not only anisotropic clustering but also regionally distinct characteristics of seismicity. The former needs a quasi-real-time cluster analysis that identifies the aftershock centroids and correlation coefficient of a cluster distribution. The latter needs the space-time ETAS model with location dependent parameters. Together with the Gutenberg-Richter's magnitude-frequency law with locationdependent b-values, the elaborated model is applied for short-term, intermediate-term and long-term forecasting of baseline seismic activity.

Extreme Threshold Failures Within a Heterogeneous Elastic Thin Sheet and the Spatial‐Temporal Development of Induced Seismicity Within the Groningen Gas Field

“…Although this Poisson point model can be extended to include aftershocks using the Epidemic-Type Aftershock Sequence model (Ogata, 2011), it is not included in this study. This choice does not affect the expected spatial-temporal density of epicenters but will likely underestimate the variance in density and the degree of interevent clustering.…”

Non-stationary ETAS to model earthquake occurrences affected by episodic aseismic transients

“…Note that there is no prior on the parameters η. They are treated as hyperparameters and are estimated by maximizing the posterior that is marginalized over f as This procedure of estimating hyperparameters by maximizing the marginalized likelihood is called the Type-II maximum likelihood procedure (Kumazawa and Ogata 2014;Ogata 2011). This procedure is also known as empirical Bayes (Bishop 2006).…”

“…Recently, Kumazawa and Ogata (2014) adapted the hierarchical modeling approach of Ogata (2004Ogata ( , 2011 to non-stationary ETAS model. In this approach, the background rate function µ(t) is expressed as a piece-wise linear function made up of linear pieces between each pair of consecutive earthquake occurrence times.…”

CSEP Testing Center and the first results of the earthquake forecast testing experiment in Japan

“…For the "All Japan" region ( Fig. 1), 9 models were submitted: HIST-ETAS5pa and HIST-ETAS7pa (Ogata, 2011), MARFS and MARFSTA (Smyth and Mori, 2011), Triple-S-Japan (Zechar and Jordan, 2010), and RI10k, R30k, RI50k, and RI100k (Nanjo, 2011). The 9 models for "Mainland" (Fig.…”