Evaluation of earthquake parameters used in the Indonesian Tsunami Early Warning System

Abstract

Twenty-two of a total of 30 earthquake events reported by the Indonesian Agency for Geophysics, Climatology and Meteorology during the time period 2007-2010 were falsely issued as tsunamigenic by the Indonesian Tsunami Early Warning System (Ina-TEWS). These 30 earthquakes were of different magnitudes and occurred in different locations. This study aimed to evaluate the performance of the Ina-TEWS using common earthquake parameters, including the earthquake magnitude, origin time, depth, and epicenter. In total, 298 datasets assessed by the Ina-TEWS and the global centroid moment tensor (CMT) method were assessed. The global CMT method is considered by almost all seismologists to be a reference for the determination of these parameters as they have been proved to be accurate. It was found that the earthquake magnitude, origin time, and depth provided by the Ina-TEWS were significantly different from those given in the global CMT catalog, whereas the latitude and longitude positions of the events provided by both tsunami assessment systems were coincident. The performance of the Ina-TEWS, particularly in terms of accuracy, remains questionable and needs to be improved.

Accurate local magnitude prediction for small to moderate earthquakes using rapid calculations of P-wave dominant period

“…This is due to increasing seismic activities and shifted trends in the hypocenters from lands to seas at depth in the regions, making the island with very long shorelines vulnerable to tsunamigenic earthquakes. In line with various techniques developed for better prediction, rapid and accurate magnitude determination is of fundamental importance to minimize negative impacts on society, such as reduction in fatalities by preventing local people from false early warnings (Satriano et al, 2011;Lomax & Michelini, 2011, 2012Madlazim et al, 2015;Madlazim & Prastowo, 2016). Although the results for the datasets used in this study are limited to moderate events occurring in localized areas of research, the method proposed is argued …”

“…Further revisions for better prediction of disastrous events were made using programming codes called Joko Tingkir (Madlazim et al, 2015). A comprehensive evaluation of earthquake parameters in the existing tsunami early warning system (Ina-TEWS) in the country was set in accordance with Joko Tingkir for local tsunamigenic earthquakes (Madlazim & Prastowo, 2016).…”

Continual Advance in Earth Physics Research Group at Physics Study Program, Unesa: What’s new and the next step

“…Since the early stage, Ina-TEWS has developed over time. For example, the warning system is now able to run effectively by taking earthquake-tsunami parameters into account for enhancing performance, where it takes only about 4 minutes for tsunami alert to be issued after a submarine earthquake occurs [33][34][35].…”

DETERMINATION OF RUPTURE DIRECTIVITY USING THE LEVENBERG-MARQUARDT ALGORITHM: A CASE STUDY PHILIPPINE EARTHQUAKE (15 DECEMBER 2019 M_w 6.8)

“…Analysis of the rupture directivity can provide critical knowledge of the mechanism of earthquake sources, one of which is to determine the actual fault plane [4][5][6]. Rupture directivity is a parameter that provides information regarding the rupture duration, the amplitude of the rupture, and the direction of rupture propagation, carrying the amount of energy from the earthquake source that can be identified by the azimuthal pattern recorded on the station network [7].…”

“…The result is that rupture directivity can determine the actual fault plane of the earthquake that occurred. Madlazim et al [5] use the rupture duration to determine the rupture directivity of the Palu earthquake on September 28, 2018. The result is that the rupture duration recorded on a seismic station in the direction of rupture propagation will produce a short duration, while seismic stations in the opposite direction of propagation rupture will result in a long rupture duration.…”