Model intensitas gempa bumi di Maluku Utara

Abstract

ABSTRAK
Nilai percepatan tanah di Maluku Utara diperoleh berdasarkan metoda Probabilistic Seismic Hazard Analysis (PSHA) dengan menggunakan perangkat lunak Earthquake Risk Model (EQRM) yang dikembangkan oleh Geoscience Australia. Nilai percepatan tanah selanjutnya dikonversi menjadi intensitas gempa bumi menggunakan persamaan Atkinson dan Kaka. Model sumber gempa bumi yang digunakan sebagai masukan dalam analisis ini adalah zona subduksi Filipina, Thrust Maluku Barat, Thrust Maluku Timur, Sesar mendatar Sorong, Sesar mendatar Sula, dan sesar-sesar yang terdapat di Pulau Morotai, Halmahera, Obi, dan Taliabu. Hasil analisis menunjukkan nilai percepatan tanah di wilayah Maluku Utara berkisar antara 0,07 hingga 1,1 g. Nilai tersebut setara dengan intensitas gempa bumi V MMI hingga IX MMI. Berdasarkan nilai kesetaraan tersebut intensitas gempa bumi di Maluku Utara dapat dibagi menjadi tiga kelompok yaitu, daerah dengan intensitas < VII MMI, VII – VIII MMI, dan intensitas > VIII MMI.
Kata kunci: intensitas, percepatan puncak, model sumber gempa bumi, PSHA

ABSTRACT
Peak ground acceleration value in North Maluku was obtained based on Probabilistic Seismic Hazard Analysis (PSHA) method by using a Software for Earthquake Risk Model (EQRM) which is developed by Geoscience Australia. Further ground acceleration value is converted into earthquake intensity by using Atkinson and Kaka Equation. The earthquake sources model which is used as an input in this analysis are Philippines Subduction, West Maluku thrust, East Maluku thrust, Sorong strike slip Fault, Sula strike slip Fault and faults which are located in Morotai, Halmahera, Obi, and Taliabu Islands. Analysis result shows that the Peak ground acceleration values in the North Maluku region range between 0.07 g and 1.1 g. This value is equal with earthquake intensity of MMI V up to MMI IX scale. Based on this equality value, the intensity of earthquake in North Maluku can be divided into three groups, namely region with intensity of < VII of MMI scale, VII –VIII of MMI scale, and the intensity of > VIII of MMI scale.
Keywords: intensity, peak ground acceleration, earthquake source, PSHA