INTEGRATION OF GEOPHYSICAL PARAMETERS ANALYSIS IN THE
EARTHQUAKE PREDICTABILITY
Boko Nurdiyanto, Hendri Subakti, I Putu Pudja
Research and Development Center, Indonesia Meteorological Climatological and Geophysical Agency (BMKG), Indonesia, boko.nurdiyanto@gmail.com
The purpose of this study is to analyze the predictability of earthquakes within a
short-term and mid-term scale in the western part of Java using various parameters, i.e seismicity, magnetic, electromagnetic, surface temperature, and humidity. In this research we use the USGS and BMKG seismic data catalogue from 1973 to 2010, the earth's surface magnetic and electromagnetic field measurements data from magnetometer and magnetotelluric observation station of BMKG at Pelabuhan Ratu, and the surface temperature and humidity data obtained from the Sukabumi AWS station of BMKG is located in Pelabuhan Ratu. The case study used was large earthquake event with a radius of 300 km from Pelabuhan Ratu observation station that are on September 2nd, 2009 (M7.5), September 13th, 2009 (M6.6), October 16th, 2009 (M6.4), November 18th, 2009 (M5.3), January 10th, 2010 (M5.3), February 20th, 2010 (M5.0), May 18th, 2010 (M6.0) and June 26th, 2010 (M6.3). From the seismicity data, seismicity anomalies was found in 2.5 - 3.5 years before earthquakes occur that are classified as mid-term precursor. Anomalous magnetic field of the magnetometer was found 2-22 days before the earthquake occurs, magnetic fields from magnetotelluric anomalies was found 2-20 days before earthquakes occur, while the
anomalous variation of surface temperature and average daily humidity was found 10 and 17 days before earthquakes occur. Anomalous magnetic field, electromagnetic, variations in surface temperature and average daily humidity is classified as a short-term precursor. And periodicity in the Java subduction zone with magnitude M6 based on the depth of the source showed a similar periodicity of dominant earthquake that is about four to five years.
Key words: Predictability, earthquake, precursor, seismicity, magnetic,
temperature, humidity.
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