identifikasi potensi pergerakan tanah pada lereng yang dipicu gempabumi berdasarkan pengukuran mikrotremor

Tanah longsor merupakan bencana yang disebabkan oleh beberapa faktor antara lain kondisi lapisan sedimen permukaan yang lunak, adanya getaran dan kodisi topografi (kemiringan lereng). Pada penelitian ini potensi gerakan tanah pada lerang yang dipicu gempabumi diidentifikasikan menggunakan pendekatan nilai ground shear strain dan pergerakan partikel yang diperoleh dari hasil analisis mikrotremor. Lokasi penelitian berada di Samigaluh, Kulon Progo yang merupakan daerah yang memiliki kerawanan tinggi mengalami tanah longsor. Data pengukuran mikrotremor sebanyak 15 titik diolah menggunakan software Geopsy. Hasil nilai ground shear strain bernilai antara 0,00045 – 0,00167 sehingga daerah penelitian rawan mengalami tanah longsor dengan potensi pergerakan tanah pada arah timur laut-barat daya. The landslide is a disaster which is caused by some factors such as the condition of soft sediment layers, the tremor, and the topography (slope). In this research, the potential of ground movement of the slope triggered by earthquake was identified by using the approach of ground shear strain value and the particle motion analysis which was obtained from the analysis results of microtremor. The location of the research was in Samiguluh, Kulon Progo. It is the area that has high insecuruty to landslide. The measurement of microtremor was in 15 points which were processed by using Geopsy software. The result of ground shear strain was about 0,00045 – 0,00167, so that the area of the research had landslide with the potential of ground movement in northeast-southwest.