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

Earth, Planets and Space

Table 1. Estimates of the models applied to the M ≥ 4 data.

Model unit	μ events/day/deg²	K events/day/deg²	c days	α 1/mag	p —	d deg²	q —	AIC, ABIC —
Space-Time ETAS0iso	1.88E-04	2.19E-04	1.58E-03	0.808	0.865	3.32E-04	1.368	49528.5
Space-Time ETAS0aniso	1.90E-04	2.14E-04	1.59E-03	0.823	0.865	3.18E-04	1.367	49407.1
Space-Time ETASiso	7.77E-05	9.63E-05	1.24E-03	1.197	0.853	2.32E-04	1.415	47972.0
Space-Time ETASaniso	7.93E-05	9.44E-05	1.24E-03	1.204	0.853	2.21E-04	1.414	47821.1
μK -HIST-ETAS0 weights	1.54E-02	2.34E-06	1.06E-02	1.680	1.150	7.57E-05	1.660	—
	0.429	0.134	—	—	—	—	—	39982.2
μK-HIST-ETAS weights	1.52E-02	2.35E-06	1.10E-02	1.430	1.160	1.06E-04	1.700	—
	0.381	0.138	—	—	—	—	—	39503.4
HIST-ETAS0 weights	1.49E-02	1.24E-05	8.82E-03	1.470	1.140	1.57E-04	1.580	—
	0.571	0.901	—	8.0	24.4	—	1440	38340.7
HIST-ETAS weights	1.76E-02	2.11E-06	1.10E-02	1.440	1.160	9.16E-05	1.690	—
	0.445	0.239	—	17.1	19.6	—	1790	37903.5

Model name that includes ‘0’ (zero) indicates that the model is applied to the data during the target period only; otherwise indicates that the model is applied to the data during the target period taking earthquakes in precursory period into consideration for the history. Models that include “aniso” or “HIST” take account of the aftershock centroid or anisotropic clusters while the model name that includes “iso” indicates that the model assumes isotropic clusters with only the original epicenters. See Section 3 for details of the data processing and the target period and precursory period.