Opak Fault Strand Delineation Using Merapi Slope Shifted Indicator


Agus Sutiono(1*), Bambang Prastistho(2), C. Prasetyadi C. Prasetyadi(3), Supartoyo Supartoyo(4)

(1) Geological Engineering, University of Pembangunan Nasional “Veteran” Yogyakarta
(2) Geological Engineering, University of Pembangunan Nasional “Veteran” Yogyakarta
(3) Geological Engineering, University of Pembangunan Nasional “Veteran” Yogyakarta
(4) Center for Volcanology and Geological Hazard Mitigation, Geological Agency of Indonesia
(*) Corresponding Author




        After the Yogya earthquake occurred on May 27, 2006, the opinions of experts split into two groups regarding location of responsible fault to earthquake shacking; (1), First group argues that Opak Fault displacement caused the earthquake. Where fault line is commonly known runs along Opak River, striking from Parangtritis Beach to Prambanan. (2) Second group of experts stated at deferent opinion, that another fault displacement triggered the earthquake shock. Where is located  at the East side of the Opak River about 10 Km. On the other-hand, this paper proposes an idea to unravel Opak Fault position by understanding, that main active fault movement underlying Bantul region has  been influencing continuum mechanical process, onto  Merapi Sediments surface since the early periods of  continuing Merapi materials sedimentation. It should has been reflected to the surface landform at above the fault strand. Further, indicates to morphotectonic feature as an en echelon slope shifted alignment. Thus, it can be the way to assist in defining attribute of main fault (PDZ) areas by using its en echelon indicator of shifting slope alignment. This paper also presents the results of determining Opak fault line location by using Digital Elevation Model (DEM-NAS) to generate custom shading in approaching landform features. With a further doing specific landscapes observations over the entire of Young Merapi deposits. There are other challenges to alternate identification of buried basin faults fill, by doing carefully identifications in morphotectonic aspects over the entire South Slope Merapi flank. It traces from Kepurun village at about elevation 400 m towards Parangtritis at 25 m of elevation. Independent field morphotectonic data sets of such scarp, terraces, water springs alignment and active cracks are encountered in the vicinity of Merapi sediments slope shifted, particularly in Tirtomartani Jetis village Kalasan. Identification of such structures obtained from morphotectonic analysis results are regarded as reliable indicator of faults, which is efficiently can be found in field.




Key word: Opak Fault, Morphotectonic, Slope Shifted, Delineation.


Key word: Opak Fault, Morphotectonic, Slope Shifted, Delineation.

Full Text:



Abidin H.Z., Andreas H., Meilano I., Gamal M., Gumilar I., dan Abdullah CI., 2009. Deformasi Koseismik dan Pascaseismik Gempa Yogyakarta 2006 dari Hasil Survei GPS. Jurnal Geologi Indonesia, Vol. 4 No. 4 Desember 2009: 275-284.

Allmendinger. R.W., (1989). Notes on Fault Slip Analysis. Department of Geological Sciences Cornell University Ithaca, New York 14853-1504.

Andreas Laake. (2011). Integrate of Satellite Imagery Geology and Geophysical Data, Earth and Environmental Sciences, Dr. Imran Ahmed Dar (Ed.), ISBN 978-953-307-468-90.

Sutiono.A.1,Prastistho.B.1.,Prasetyadi.C.2., and Supartoyo2,. 2018. Opak fault: A comparative review
1 Geological Engineering, University of Pembangunan Nasional Veteran Yogyakarta. 2 Center for Volcanology and Geological Hazard Mitigation, Geological Agency of Indonesia. ICEMINE IOP Conf. Series: Earth and Environmental Science 212 (2018) 012049 IOP Publishing

Bambang S Widijono dan Budi Setyanta 2007 Anomali Gaya Berat, Kegempaan Ser Kelurusan Geologi Daerah Yoyakarta dan Sekitarnya Pusat Survey Geologi JSDG vol XVI

Choia. J. H., Edward.P., Kyoungtae Koa,c, Kima.Y-S., Definition and Classification of fault damage zones: A review and a new methodological approach Earth-Science Reviews journal homepage: www.elsevier.com/locate/earscirev.

IAN M. WATKINSON* & ROBERT HALL 2017 Fault systems of the eastern Indonesian triple junction: evaluation of Quaternary activity and implications for seismic hazards. SE Asia Research Group, Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK http://sp.lyellcollection.org/ at Royal Holloway, University of London on May1,2017.

Sylvie Schueller a,*, Alvar Braathen a,b, Haakon Fossen a,c, Jan Tveranger a 2013. Spatial distribution of deformation bands in damage zones of extensional faults in porous sandstones: Statistical analysis of field data. a Centre for Integrated Petroleum Research (CIPR), Uni Research, P.O. Box 7810, 5020 Bergen, Norway. b University Centre in Svalbard, 9171 Longyearbyen, Norway c Department of Geoscience/University Museum of Bergen, University of Bergen, P.O. Box 7803, 5020Bergen, Norway.

Takeshi Tsuji1 et al 2009 Earthquake fault of the 26 May 2006 Yogyakarta observed by SAR interferometry.

DOI: https://doi.org/10.22146/jag.55276

Article Metrics

Abstract views : 400 | views : 295


  • There are currently no refbacks.

Copyright (c) 2022 Agus Sutiono, Bambang Prastistho, C. Prasetyadi C. Prasetyadi, Supartoyo Supartoyo

Journal of Applied Geology Indexed by:


Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.