Abstract Database


Md. Mominur RAHMAN
Supervisor: Tatsuhiko HARA
Country: Bangladesh
We analyzed 56 earthquakes that occurred in and around Bangladesh between June 2016 and February 2019. We picked arrival times from waveform data of the local network of Bangladesh Meteorological Department. Then we determined hypocenters of those events. We investigated the detectability of the local network. Some events that occurred in Bangladesh especially in the western part that are not registered in the ISC bulletin were detected by the local network. On the other hand, the local network did not detect some events which occurred in Bangladesh that were registered in the ISC bulletin. Then we compared the hypocenters determined by the local network data to those retrieved from the ISC bulletin and the USGS catalog. The differences between hypocenters are less than about 50 km in the epicentral distance from the centroid of the local network up to 300 km. The differences are larger at the greater epicentral distance for some events. We found the tendency that intermediate depths events were located as shallow earthquakes. We combined the arrival times from the local network and the arrival times recorded in the epicentral distance up to 10 degrees from the ISC bulletin and the USGS catalog. Then we determined the hypocenters using the combined data and compared the hypocenters with those retrieved from the ISC bulletin and the USGS catalog. The large differences between hypocenters found for the analysis using only local data are reduced.    
Keywords: Hypocenter determination, Detectability, Comparison of hypocenters, Combination of arrival time data.