Claim Missing Document
Check
Articles

Found 2 Documents
Search

Jejak tsunami 25 Oktober 2010 di Kepulauan Mentawai berdasarkan penelitian kebumian dan wawancara Yudhicara Yudhicara; Widjo Kongko; Velly Asvaliantina; Suranto Suranto; Sapto Nugroho; Andrian Ibrahim; Widodo S. Pranowo; Nils B. Kerpen; Knut F. Kramer; Oliver Kunst
Jurnal Lingkungan dan Bencana Geologi Vol 1, No 3 (2010)
Publisher : Badan Geologi

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (4740.995 KB) | DOI: 10.34126/jlbg.v1i3.19

Abstract

SARITsunami Mentawai yang terjadi pada 25 Oktober 2010 adalah kategori tsunami earthquake. Ciri dari kategori ini, antara lain guncangan gempa bumi terasa lemah tetapi berlangsung lama (~ 3 menit) dan menghasilkan tsunami cukup besar. Parameter tsunami yang terukur di lapangan, diketahui bahwa ketinggian run up maksimum 12,4 m di Pulau Sibigou, jarak genangan maksimum 450 m di Dusun Malakopa, kedalaman batimetri dekat pantai 2-15 m, dan ketebalan endapan pasir tsunami mencapai 12cm di Teluk Makaroni. Berdasarkan keterangan dari saksi mata, sebelum tsunami berlangsung indikasinya adalah suara gemuruh dari arah laut dan perilaku burung camar yang mengeluarkan suara yang gaduh. Gelombang tsunami tiba di pantai 5-10 menit setelah guncangan gempa bumi sebanyak 3 sampai 4 kali gelombang. Gelombang yang kedua dianggap paling tinggi.Kata kunci: gempa bumi, Tsunami Mentawai, ketinggian run up, jarak genanganABSRACTTsunami Mentawai of 25 October 2010 is take in to tsunami earthquake catagory, which has weak shaking and slow duration (~ 3 minutes), but produce big tsunami. Tsunami parameter measurement obtained the maximum run up of 12.4 meters at Sibigou Island, maximum inundation of 450 meters at Malakopa Village, near coast bathymetry of 2-15 meters and tsunami sand deposits up to 12 cm at Makaroni Bay. According to the eyewitnesses, there are some precursors such as roaring sound from the sea and bird noisy sounds heard before the tsunami came. Tsunami arrived 5-10 minutes after earthquake, come inland about 3 to 4 times and the second wave was the highest.Keywords: earthquake, Tsunami Mentawai, run up, inundation
Delineation of Banyumas Sub-Basins using Gravity Anomaly Based on Trend Surface Analysis Equation Hidayat Hidayat; Marjiyono Marjiyono; Zulilmatul S Praromadani; Januar H.Setiawan; G.M. Lucki Junursyah; Subagio Subagio; Ahmad Setiawan; Andrian Ibrahim
Jurnal Geologi dan Sumberdaya Mineral Vol. 22 No. 4 (2021): JURNAL GEOLOGI DAN SUMBERDAYA MINERAL
Publisher : Pusat Survei Geologi

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33332/jgsm.geologi.v22i4.651

Abstract

A study using gravity methods in the Banyumas Basin, located in the southern part of Central Java, Indonesia had been conducted to generate a map for regional geological features in sub-volcanic basin related to petroleum system. This study used the first and second-order of Trend Surface Analysis (TSA) to separate gravity anomaly into regional and residual components. Matrix inversion is applied to obtain constants values for both the first and second-order of TSA. To interpret geological features related to oil and gas study, residual components are used for gravity anomaly. Residual anomaly is also compared for both first and second order of TSA with a regional geological map to validate the result. Residual anomaly from the second order of TSA showed a very comparable result to geological features, as shown in the regional geological map, compared to those of the first order of TSA. These results also showed a strong contrast of some important geological features such as the Gabon-Nusakambangan Formation outcrop, Karangbolong outcrop, and the eastern part of the south Serayu mountain arc. This study also displayed two potential subbasins i.e Citanduy and Majenang sub-Basin that might be a possible setting in which source rocks of the Banyumas Basin were deposited. From this study, it can be concluded that TSA showed a reliable result of separating gravity anomaly data set into regional and residual components.Keywords: Gravity anomaly, Banyumas Basin, petroleum system, trend surface analysis (TSA).