STUDI KORELASI DURASI EXEED 50S (T50Ex) GEMPA BUMI TELESEISMIK DENGAN TERJADINYA TSUNAMI DI INDONESIA

Abstract

Abstrak Indonesia merupakan salah satu negara rawan gempa bumi dikarenakan Indonesia dilalui oleh jalur pertemuan 3 lempeng tektonik untuk mengurangi dampak bencana maka dilakukan penelitian yang bertujuan untuk menganalisis hubungan durasi exeed 50s (T50Ex) gempa bumi teleseismik dengan terjadinya tsunami di Indonesia. Metode yang digunakan untuk menganalisis adalah korelasi data kualitatif dengan menggunakan X-square hitung > X-square table. Penelitian ini didapatkan 32 data event gempa bumi dari Wilber3 di mana terdapat 25 data yang sesuai dan 7 data yang tidak sesuai antara perhitungan T50Ex melalui software Joko Tingkir dengan database NOAA., hal ini diakibatkan terjadi gangguan (noise) terlalu besar setiap masing-masing stasiun dan distribusi stasiun tidak melingkup disekitar episenter. Dari hasil penelitian di dapatkan X-square hitung > X-square table sebesar 9,34 > 3,841, artinya terdapat korelasi antara T50Ex dengan terjadinya tsunami dengan nilai taraf signifikan yang digunakan adalah 95% maka batas kritid 0,05 pada degree of freedom (DF) 1 dan di dapatkan nilai koefisien korelasi sebesar 0,47. Kata kunci : gempa bumi teleseismik, durasi exeed 50s (T50Ex), degree of freedom (DF) Abstract Indonesia as one of earthquake prone countries due to Indonesia passed by meeting path of 3 tectonic plates to reducing the earthquake impact disaster it is important to perform a research with purpose to analyzes the correlation of exceed 50s (T50Ex) duration of teleseismic earthquake concurrent with the tsunami incidence in Indonesia. This research using teleseismic earthquake data in Indonesia with 32 data that taken from Wilber 3. The average result T50ex gained from some difference earthquake recorder station, from 32 earthquake event data found 25 suitable data and 7 data unsuitable between T50Ex computation through JokoTingkir software with NOAA database. Database in NOAA not tsunami but value of T50Ex > 1 happen in earthquake in Seram Island on January 28th 2004 have value It = 0, T50Ex = 1,19 and North Sumatera o April 6th 2010 have value It = 0, T50Ex = 1,68. While NOAA tsunami data but value of T50Ex < 1 happened Halmerah earthquake on January 21st 1994 with It = 2 T50Ex = 0,68; Sulawesi Mei4th 2000 with It = 6 T50Ex = 0,43; Alor Isles September 11th2004 have value of It = 2 T50Ex = 0,7; Seram Island March 14th 2006 with It = 9 T50Ex = 0,56 and Tasikmalaya Juli 17th2006 with Mw= 7,2 have value of It = 18 T50ex = 0,8 , it is caused noise too much in each station and station distribution uncovered around epicenter. From this qualitative data research result using X-square calculation > table X-square = 9,34 > 3,841, means there is positive correlation between T50Ex tsunami happened with significant level value that used is 95% then critically limit 0,05 in degree of freedom (DF) 1 and get correlation coefficient value 0,47. Keywords: teleseismic earthquake, exeed 50s duration, Degree of freedom (DF).