Identification of earthquake hazard areas using microtremor refraction (Remi) in central sukoharjo district

Abstract

Study about microtremor method has been done in Sukoharjo regency. This study aims to determine and mapping the earthquake-prone areas as mitigation efforts based on dominant frequency parameters, dominant periods, and amplification factors. Data acquisition is performed at 19 sites with intervals of each location 2 – 3 Km. P.A.S.I Seismograph 16S24-P is used to acquiring the data. The data acquisition is done with a duration of 20 minutes in three times repetitions. Microtremor data processing using the Geopsy software. Based on HVSR curve analysis, obtained the dominant frequency and amplification factor values. From the result of parameter analysis obtained is made of earthquake hazard map by reviewing the soil classification that has become the standard geological parameter of a region. The dominant period in type IV has a degree of vulnerability to earthquakes, as it has a dominant period of more than 0.75. Type IV is located on Parangjoro, Gadingan, Dukuh, and Jetis areas with the dominant period in 2.43 s until 2.63 s. Most of Sukoharjo areas have low amplification in the zone I with amplification between 1.11 and 2.92.