A Threshold-Based Earthquake Early-Warning System for Offshore Events in Southern Iberia

Abstract

The south of the Iberian Peninsula is a region situated at the convergence of the Eurasian and African plates. This region experiences large earthquakes with a long separation in time, the best known of which is the great 1755 Lisbon Earthquake (i.e., maximum macroseismic intensity, I max =X), which occurred SW of San Vicente Cape (SW Iberian Peninsula). The high risk of damaging earthquakes has recently lead Carranza et al.(2013) to investigate the feasibility of an EEWS in this region. The analysis of the geometrical situation between the Iberian seismic networks and the San Vicente Cape area led the authors to conclude that a threshold-based approach, which would not require the real-time location of the earthquake, might be the best option for EEWS in SW Iberia.The current work explores this hypothesis, and proposes a new EEW approach that extends the standard P-wave threshold based single station analysis to the whole network.The proposed method allows the real-time estimation of the potential damage at stations that are triggered by P-waves, as well as at the not-triggered ones, giving the advantage of a greater lead-time for the release of alerts. Results of tests made with synthetic data mimicking the scenario of the great 1755 Lisbon Earthquake, and those obtained by applying the new approach to available recordings, indicate that an EEW estimation of the potential damage associated with an event in the San Vicente Cape area can be obtained for a very large portion of the Iberian Peninsula.2

New τc regression relationship derived from all P wave time windows for rapid magnitude estimation

“…After several decades of development, EEWSs for real-time earthquake hazard mitigation are now operational in many countries worldwide, such as Japan [Nakamura, 1988;Hoshiba et al, 2008], Turkey [Erdik et al, 2003;Sesetyan et al, 2011], Taiwan Hsu et al, 2016], Mexico [Espinosa-Aranda et al, 2009], and Romania [Allen et al, 2009]. EEWSs are in the development and testing stages in southern Italy [Satriano et al, 2011], California [Allen et al, 2009;Kuyuk et al, 2014], China [Peng et al, 2011;Peng et al, 2015;Zhang et al, 2016], Iran [Reza et al, 2013], northeastern Italy, Slovenia and Austria [Picozzi et al, 2015a], and southern Iberia [Picozzi et al, 2015b].…”

A Low-Latency Seismic Recorder for Earthquake Early Warning

“…Earthquake early warning system (EEWS) is one of the most effective ways for earthquake disaster mitigation. Many countries and regions around the world have already developed EEWSs, such as California [1] [2], Japan [3] [4], Mexico [5], Taiwan [6] [7], Italy [8], or are developing and testing the prototype systems, including Turkey [9], China [10][11][12][13], Iberia [14], etc.…”

Trans-national earthquake early warning (EEW) in north-eastern Italy, Slovenia and Austria: first experience with PRESTo at the CE<sup>3</sup>RN network

“…Horiuchi et al, 2005;Wu and Zhao, 2006;Espinosa-Aranda et al, 2009;Böse et al, 2007Böse et al, , 2009. EEWSs are also under development and testing in other regions of the world, such as Italy, Turkey, Spain, and China Zollo et al, 2014;Alcik et al, 2009;Peng et al, 2011;Picozzi et al, 2014Picozzi et al, , 2015b.…”