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

Twenty-two of a total of 30 earthquake events reported by the Indonesian Agency for Geophysics.Climatology and Meteorology during the time period2007-2010 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.