KORELASI POLARISASI MAGNET Z/H UNTUK IDENTIFIKASI PREKURSOR GEMPA DI SEKITAR PELABUHAN RATU

Authors

  • Asep Saepul Ahyar Jurusan Fisika, Fakultas Sains dan Teknologi UIN Sunan Gunung Djati, Jl. A.H. Nasution 105, Bandung, 40614.
  • Bambang Sunardi Puslitbang BMKG, Jl. Angkasa 1 No. 2 Kemayoran, Jakarta 10720.

DOI:

https://doi.org/10.21009/SPEKTRA.023.03

Abstract

Abstrak

Efek seismo-elektromagnetik yang berlangsung dalam rentang frekuensi luas yang mendahului gempa telah banyak dilaporkan dalam beberapa penelitian sebelumnya. Efek tersebut diharapkan dapat dimanfaatkan dalam mitigasi bencana gempa. Penelitian ini membahas penerapan metode korelasi polarisasi magnet komponen Z/H untuk mengidentifikasi prekursor gempa di sekitar Pelabuhan Ratu. Data yang dipergunakan adalah data magnet tiga komponen selama 31 hari sebelum kejadian gempa. Identifikasi  anomali  geomagnet dilakukan  dengan  menerapkan metode korelasi polarisasi magnet Z/H untuk  menghitung  rasio Simpangan koefisien  korelasi (Skk)  dengan  Deviasi  standar  simpangan  koefisien korelasi  (Dskk). Ambang batas anomali adalah -1. Nilai Skk/Dskk < -1 mengindikasikan adanya anomali geomagnet. Kemunculan badai magnetik yang mempengaruhi anomali geomagnet dievaluasi menggunakan Disturbance storm time index (indeks Dst). Hasil penerapan metode korelasi polarisasi magnet Z/H pada lima kasus gempa di sekitar Pelabuhan Ratu dari Januari – Maret 2017 dengan magnitudo M  > 4 dan memenuhi radius zona manisfestasi prekursor menunjukkan kemunculan anomali geomagnet yang dikategorikan sebagai prekursor gempa. Kemunculan anomali geomagnet berkisar antara 16 – 2 hari sebelum gempa terjadi.

Kata-kata kunci: korelasi, geomagnet, prekursor gempa, Pelabuhan Ratu.

Abstract

Seismo-electromagnetic effects occurring in wide frequency range that preceded earthquake have been widely reported in several previous studies. The effect is expected to be utilized in earthquake disaster mitigation. This study discusses application of magnetic polarization correlation method of Z / H component to identify earthquake precursors around Pelabuhan Ratu. Data used are three components magnet data for 31 days before earthquake events. Identification of magnetic anomaly was done by applying the magnetic polarization Z / H method to calculate correlation coefficient ratio (Skk) with standard deviation of correlation coefficient deviation (Dskk). The anomaly threshold is -1. Less than -1 of Skk / Dskk values indicate geomagnetic anomaly. The emergence of geomagnetic storms that affect geomagnetic anomalies is evaluated using the Disturbance storm time index (Dst index). The result of application of Z / H magnet polarization correlation method in five earthquake cases around Pelabuhan Ratu from January to March 2017 with magnitude M > 4 and meeting precursor manifestation radius zone showed the occurrence of geomagnetic anomalies categorized as earthquake precursors. The appearance of geomagnetic anomalies ranged from 16 to 2 days before earthquakes occurred.

Keywords: correlation, geomagnetic, earthquake precursor, Pelabuhan Ratu.

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Published

2017-12-30

How to Cite

Ahyar, A. S., & Sunardi, B. (2017). KORELASI POLARISASI MAGNET Z/H UNTUK IDENTIFIKASI PREKURSOR GEMPA DI SEKITAR PELABUHAN RATU. Spektra: Jurnal Fisika Dan Aplikasinya, 2(3), 179–186. https://doi.org/10.21009/SPEKTRA.023.03

Issue

Vol. 2 No. 3 (2017): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 2 Nomor 3, Desember 2017

Section

Articles

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