Microseismic research using coherence and cross-correlation in Depok, Sleman, Yogyakarta

[摘要] Yogyakarta area is one of earthquake-prone area in Indoneis. It is include in the Indo-Australian plate subduction zone under the Eurasian plate. It also has an active fault, namely Opak fault that located in Bantul Regency. Microseismic method is one way that can be used to analyze soil vulnerability of earthquakes. The Microseismic method is a geophysical method that utilizes natural vibrations as its source. The data of the Microseismic Method is processed using HVSR Method. It is used to compare horizontal to vertical spectra ratio. The results of HVSR shows the value of the dominant frequency (f 0), amplification (A 0) the Soil Vulnerability Index (Kg). The results of this research that especially located in Depok District, Sleman Regency has the dominant frequency value that range from 0.65 to 1.35 Hz, amplification value between 2.6 and 5.6 and soil susceptibility value is 4-52 s2 / cm. The data obtained from the southern part of the research area, it shows that it has dominant frequency and high amplification values. To reassure the data, coherence graphs, phase velocity graphs and cross correlation maps were made between amplification maps with dominant frequencies, dominant frequency maps with topography, amplification maps with topography and maps of soil vulnerability index with topography. Coherence and correlation cross graphs show a small link to the south of the research area.

[发布机构] Department of Geophysical Engineering, Universitas Pembangunan Nasional Veteran Yogyakarta, Indonesia^1;Agency for Meteorology, Climatology and Geophysics (BMKG) Yogyakarta, Indonesia^2

[效力级别] 矿业工程

[关键词] Active fault;Cross correlations;Dominant frequency;Eurasian plates;Geophysical methods;Natural vibration;Plate subduction;Vulnerability index