Moment magnitudes for large earthquakes (Mw ≥7.0) derived in real time from near-field seismic data can be underestimated due to instrument limitations, ground tilting, and saturation of frequency/amplitude-magnitude relationships. Real-time high-rate GPS resolves the buildup of static surface displacements with the S wave arrival (assuming nonsupershear rupture), thus enabling the estimation o...

Earthquake early warning (EEW) systems are used to provide timely alerts on ongoing earthquakes, which can facilitate important risk-mitigation actions before potentially damaging seismic waves reach target sites. A major shortcoming of existing EEW approaches is that the earthquake-related conditions for activating not generally defined according a formal decision-support system (DSS) accounts...

This paper discusses the design of a social media crisis mapping platform for decision making in natural disasters where tweets are analysed to achieve situational awareness during earthquake and tsunami events. A qualitative end user evaluation is undertaken on our first prototype system to get feedback from practitioners working in the field of hazard detection and early warning. Participatin...

We attempt to automatically detect earthquake events in distributed acoustic sensing (DAS) data via a supervised learning approach. Detecting earthquakes with different magnitudes could potentially provide the ability of predicting major catastrophic events. Introduction Distributed acoustic sensing (DAS) is an emerging technology used to record seismic data that employs fiber optic cables as a...

This paper reviews the Quake-Catcher Network (QCN), a distributed computing seismic network that uses lowcost USB accelerometers to record earthquakes, and discusses the potential to incorporate QCN stations with traditional seismic networks. These very dense urban networks could then be used to create a working earthquake early warning system, as has been shown by our preliminary tests of the ...

Several widely implemented and tested earthquake early warning algorithms employ empirical equations that relate earthquake magnitudes with groundmotion peak amplitudes and hypocentral distances. This approach is effective to the extent that the offline dataset available for setting the fitting coefficients in those equations is of sufficient quality and quantity. However, to address the proble...

The 2004 Great Sumatra-Andaman earthquake had an average source duration of about 500 sec. and a rupture length of 1 ,200–1,300 km. The seismic moment, M0, determined with a finite source model, was 6.5 1022 N-m, which corresponds to Mw=9.18. Allowing for the uncertainties in the current M0 determinations, Mw is in the range of 9.1 to 9.3. The tsunami magnitude Mt is 9.1, suggesting that the ov...