We report the retrospective analyses of frequency-magnitude distributions (FMD) and pattern informatics (PI) for the Pingtung offshore doublet earthquakes having magnitudes 6.7 and 6.4. The frequency-magnitude distributions of earthquakes that occurred in the study area preceding the Pingtung doublets demonstrate the activation of moderate events since March 2004, about three years before the P...

There are a sparse number of credible source models available from past earthquakes and a stochastic source model generation algorithm thus becomes necessary for robust risk quantification using scenario earthquakes. We present an algorithm that combines the physics of fault rupture as imaged in laboratory earthquakes with stress estimates on the fault constrained by field observations to gener...

We have identified three groups of deep earthquakes showing nearly identical waveforms in the Tonga slab. Relocation with a cross-correlation method shows that each cluster is composed of 10 to 30 earthquakes along a plane 10 to 30 kilometers in length. Some of the earthquakes are colocated, demonstrating repeated rupture of the same fault, and one pair of events shows identical rupture complex...

Considering a disastrous earthquake as a rare event, the aim of this study is to apply the proposed data construction method (DCM) to determine the possible distribution pattern of disastrous earthquakes in Taiwan. Owing to the availability of only a limited amount of data and based on the multiset division of DCM, virtual samples have been generated. The procedure is illustrated by a numerical...

We developed an algorithm especially adapted to single-station wavelet detection of geomagnetic events, which precede or accompany the earthquakes. The detection problem in this situation is complicated by a great variability of earthquakes and accompanied phenomena, which aggravates finding characteristic features of the events. Therefore we chose to search for the characteristic features of b...

The 2011 Tohoku-Oki Earthquake is a typical subduction-zone earthquake and is the 4th largest earthquake after the beginning of instrumental observation of earthquakes in the 19th century. In fact, the 2011 Tohoku-Oki Earthquake displaced the northeast Japan island arc horizontally and vertically. The displacement largely changed the tectonic situation of the arc from compressive to tensile. Th...

The 2011 off the Pacific coast of Tohoku earthquake (Mw9.0), which produced many strong motion records, provides an opportunity to examine the characteristics of strong ground motion from a gigantic earthquake. In this paper, the preliminary analysis of the ground motion attenuation, spectral shape and duration was performed using the selected strong motion records of the earthquake. The result...

We analyzed four pairs of a large (Mw "'6) and a small (Mw "' 3.5 to 4) shallow strike-slip earthquakes to investigate the scale-dependence. of the seismic energy-tomoment ratio, an important macroscopic parameter which reflects the basic physical process of seismic slip. These earthquakes occurred in the south-western part of Japan, and high-quality close-in records (epicentral distance< 50 km...

The recently developed matched filter technique is effective in detecting earthquakes during intensive aftershock or swarm sequences. However, currently our detection code can only process on single-CPU computers, which takes a long time to perform the cross-correlation between continuous seismic data and template events. In this paper, we present a GPU-based computation method to significantly...

A system for extracting and visualizing trend information about earthquakes from tagged corpus, which is distributed by a Workshop on Multimodal Summarization for Trend Information (MuST), is proposed. The topic of earthquakes does not contain only temporal trends, which are main concerns of typical topics such as gas price and stock price movement, but also spatial trends including the seismic...