A structure may be subject to several aftershocks after a mainshock. In many seismic design provisions, the effect of sequences is either not directly considered or has been underestimated. This study examined behavior reinforced concrete (RC) moment-resisting structures with shear walls under sequences. Two three-dimensional short and medium height were designed analyzed seven real mainshock–a...

INTRODUCTION IN 1953, through cooperation of the Bernard Price Geophysical Institute of the University of the Witwatersrand and the University of Natal, a Columbia University-type long-period seismometer (To = 15 sec., Tg = 75 sec.) was installed in the seismological observatory of the University of Natal at Pietermaritzburg, Union of South Africa. This instrument was well situated for receivin...

Foreshock events provide valuable insight to predict imminent major earthquakes. However, it is difficult to identify them in real time. In this paper, I propose an algorithm based on deep learning to instantaneously classify a seismic waveform as a foreshock, mainshock or an aftershock event achieving a high accuracy of 99% in classification. As a result, this is by far the most reliable metho...

This paper discusses the design and implementation of a Pythonbased toolset to aid in assessing the response of the UK’s Advanced Gas Reactor nuclear power stations to earthquakes. The seismic analyses themselves are carried out with a commercial Finite Element solver, but understanding the raw model output this produces requires customised post-processing and visualisation tools. Extending the...

A measure of the correlation between two earthquakes is used to link events to their aftershocks, generating a growing network structure. In this framework one can quantify whether an aftershock is close or far, from main shocks of all magnitudes. We find that simple network motifs involving links to far aftershocks appear frequently before the three biggest earthquakes of the last 16 years in ...

In response to the marked number of injection-induced earthquakes in north-central Oklahoma, regulators recently called for a 40% reduction in the volume of saltwater being injected in the seismically active areas. We present a calibrated statistical model that predicts that widely felt M ≥ 3 earthquakes in the affected areas, as well as the probability of potentially damaging larger events, sh...

Geofluids is important for understanding volcanic and earthquake generation processes. In this study, we obtained a detailed seismic velocity structure in and around the Naruko volcano, northeastern Japan, using data from a dense seismic observation network. We found a distinct seismic low-velocity zone (LVZ) beneath the Naruko volcano, with a diameter of nearly 10 to 20 km in the lower crust. ...

This paper proposes a new algorithm to estimate the maximum likelihood parameters of an Epidemic Type Aftershock Sequences (ETAS) model. It is based on Simulated Annealing, a versatile method that solves problems of global optimization and ensures convergence to a global optimum. The procedure is tested on both simulated and real catalogs. The main conclusion is that the method performs poorly ...

ABSTRACT The epidemic-type aftershock sequence (ETAS) model is a powerful statistical to explain and forecast the spatiotemporal evolution of seismicity. However, its parameter estimation can be strongly biased by catalog deficiencies, particularly short-term incompleteness related missing events in phases high-seismic activity. Recent studies have shown that these fluctuations completeness mag...