Microtremor Measurements on Landslide Site at Pattiro Village, Gowa Regency

Landslide on Pattiro Village, Gowa Regency occurred at the end of May 2022. We measured microtremors at 14 locations within the landslide area. The horizontal-vertical spectral ratio (HVSR) method was then used to process and analyze these data in order to determine the resonance frequency ( f 0 ) and H/V amplification factor ( A 0 ). We divided the measurement location into 3 segments. First, we measured 7 points of site on the landslide site. The second segment was measured on 4 points, distanced 5 meters to the north from the first segment location which was non-landslide segment. On the third location we measured 2 points of site, located to the northwest about 120 meters from the first and second segments. The predominant frequency ( f 0 ) values range from 5.07 Hz to 6.78 Hz, and the amplification factor ( A 0 ) for these three segments ranges from 2.28 to 7.45. The results consistent with Kanai Classification, that predominant frequency ( f 0 ) value from 4 Hz to 10 Hz as described as surface sediment thickness are from 5 meters to 10 meters which is categorized into medium level. Moreover, the H/V amplification factor ( A 0 ) values in this study are categorized into ‘medium risk’ level.