Early forecasting of aftershocks has become realistic and practical because of real-time detection of hypocenters. This study illustrates a statistical procedure for monitoring aftershock sequences to detect anomalies to increase the probability gain of a significantly large aftershock or even an earthquake larger than the main shock. In particular, a significant lowering (relative quiescence) ...

1, Path calibration using the aftershock The calibration is obtained by convolving the mainshock data with the 1D synthetic of the aftershock and then deconvolving with the data of the aftershock. We have applied a 1Hz low-pass filter to the calibrated data because the effect of 3D slab structure in the source region cannot be ignored at higher frequency (>1Hz) (Fig.S1). The mechanism of the af...

We investigate global variations in the pattern of aftershock area expansion associated with large subduction zone earthquakes. The expansion of aftershock areas with time is relatively small in the subduction zones of Alaska, the Aleutians, Mexico, and parts of the Kuriles and South America. These subduction zones are interpreted to be characterized by moderate to strong interplate coupling. I...

Earthquakes and aftershock sequences follow several empirical scaling laws: One of these laws is Båth's law for the magnitude of the largest aftershock. In this work, Modified Form of Båth's Law and its application to KOERI data have been studied. Båth's law states that the differences in magnitudes between mainshocks and their largest detected aftershocks are approximately constant, independen...

Characterizing the evolution of seismicity rate of early aftershocks can yield important information about earthquake nucleation and triggering. However, this task is challenging because early aftershock seismic signals are obscured by those of the mainshock. Previous studies of early aftershocks employed high-pass filtering and template matching but had limited performance and completeness at ...

Compound aftershock sequences are of special interest because the decay of secondary aftershocks contains information about the mechanisms that generate all earthquakes. If earthquakes nucleate as a result of accelerating slip, growing cracks, or any similar failure process, then the rate of decay of aftershock sequences is a direct result of that failure process, as influenced by local materia...

We analyzed the most relevant seismic sequences occurred from 1977 to 2007 in the FriuliVenezia Giulia region (northeastern Italy) and western Slovenia. The 8 aftershock sequences were triggered by low to moderate magnitude earthquakes with mainshock duration magnitude ranging from 3.7 to 5.6. The b-value of the Gutenberg-Richter law varies from 0.8 to 1.1. The modified Omori’s modeling of the ...

Both earthquake size-distributions and aftershock decay rates obey power laws. Recent studies have demonstrated the sensibility of their parameters to faulting properties such as focal mechanism, rupture speed or fault complexity. The faulting style dependence may be related to the magnitude of the differential stress, but no model so far has been able to reproduce this behaviour. Here we inves...

The potential locations of aftershocks, which can be large and damaging, are often forecast by calculating where the mainshock increased stress. We find, however, that the mainshock-induced stress field is often rapidly altered by aftershock-induced stresses. We find that the percentage of aftershocks that are secondary aftershocks, or aftershocks triggered by previous aftershocks, increases wi...

A shallow destructive inland earthquake of M6.8 occurred on Oct. 23, 2004 (JST) in the middle part of Niigata prefecture, Japan. The aftershock activity was high as compared to those of the other shallow inland earthquakes in Japan. We relocated the sources of the main shock and aftershock activity by adopting the double-difference earthquake location algorithm. The precisely relocated hypocent...