PERBANDINGAN DAN PENENTUAN WINDOW EFEKTIF PADA TIGA METODE PENENTU WAKTU TIBA GEMPA UNTUK KEJADIAN GEMPA VULKANO TEKTONIK DI GUNUNG MERAPI; THE COMPARISON AND EFFECTIVE WINDOW DETERMINATION FOR THREE DISTINCT ARRIVAL-TIME PICKING METHODS IN VOLCANO TECTONICS EVENT AT MT. MERAPI

Lutfiananda, Fathia, Imam Suyanto

2016 | Skripsi | FMIPA

There are some methods which have ability to pick arrival time of volcanic earthquakes from seismic records of Merapi volcano. Those methods are STA/LTA, LTE/STE, and MER. They using calculation of amplitude within a certain timeframe for pick the onset of arrival time of an earthquake (window). This window will greatly effect to the accuracy of arrival time picking. Therefore, it is necessary to determine the effective window for each time-picking method. The test result on 5 Volcano Tectonics events at Mt. Merapi, there can be concluded that the best window for STA around 0.5 to 1.2 seconds, and for LTA around 60 to 120 seconds. For LTE/STE method, the best window is around 0.5 to 1.3 seconds for LTE, and around 0.05 to 0.25 seconds for STE. The best window for MER method is around 1 to 1.05 seconds. The test was also showing that MER gave the most stable and good respond than STA/LTA and LTE/STE to pick arrival time of earthquakes.

Kata Kunci : Arrival time of volcanic earthquakes; STA/LTA; LTE/STE, MER, Effective window; Volcano tectonics; Mt. Merapi