Identifikasi Diskontinuitas Mantel Memanfaatkan Data Prekursor SS di Sekitar Palung Mariana

Fahruddin Fahruddin; Muhammad Mulana; Ibrahim Sota; Sudarningsih Sudarningsih; Syamsulrijal Syamsulrijal; Altin Massinai; Bambang Harimei

doi:10.20527/flux.v22i2.22343

Identifikasi Diskontinuitas Mantel Memanfaatkan Data Prekursor SS di Sekitar Palung Mariana

Fahruddin Fahruddin, Muhammad Mulana, Ibrahim Sota, Sudarningsih Sudarningsih, Syamsulrijal Syamsulrijal, Altin Massinai, Bambang Harimei

Abstract

Setiap tahun terjadi gempa di berbagai daerah di dunia. Gempa bumi merujuk pada guncangan tiba-tiba pada bumi yang disebabkan oleh penjalaran gelombang seismik melalui batuan di bawah permukaan bumi. Palung Mariana dan sekitarnya merupakan zona pertemuan antara 2 lempeng tektonik yang aktif yaitu lempeng Filipina dan Pasifik. Pertemuan lempeng ini mengakibatkan terbentuknya zona subduksi di sepanjang kepulauan Mariana, merupakan palung terdalam di Bumi. Data prekursor fasa gelombang seismik SS, berguna untuk menentukan bouncepoints antara sumber gempa dengan stasiun penerima gempa dan dapat digunakan untuk mengidentifikasi keberadaan diskontinuitas mantel di sekitar Palung Mariana. Data gempa yang digunakan memiliki kedalaman kurang dari 75 km berkekuatan lebih dari 5,8 Magnitudo dan jarak episentrum lebih dari 100°. Titik bouncepoints ditentukan berdasarkan jarak antara pusat gempa dengan stasiun penerima, dengan 15 titik bouncepoints di daerah penelitian. Hasil analisa gelombang gempa diperoleh tiga gelompang prekursor yang terletak pada waktu 110 , 220 dan 450 detik.

Keywords

Palung Mariana, Diskontinuitas mantel, Gelombang seismik SS

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DOI: http://dx.doi.org/10.20527/flux.v22i2.22343