Identifikasi Struktur Sesar Gunung Muria Menggunakan Data Satelit Gravitasi

Sorja Koesuma, Ferdinan Hotman Sibarani, Budi Legowo

Abstract

Abstract: The north coast of Jepara is a region where the development of Muria nuclear power plant takes place which is chosen by the central government through National Nuclear Energy Agency of Indonesia. This nuclear power plant is located in Muria peninsula which will be affected because of tectonics and volcanic activities in such area, mainly in Muria mountain. This study uses gravimetric method to determine the subsurface structure in Muria mountain area. The gravity data is obtained from https://topex.ucsd.edu/cgi-bin/get_data.cgi is dispersed in Muria mountain. The value of anomaly which is obtained is reduced with several corrections and the value of Complete Bouguer Anomaly is achieved. The separation of regional and residual anomaly uses Second Vertical Derivative. The modeling of subsurface used forward modelling method. From this modelling, the rock density widening is in the value of 2.4 g/cm3 for basalt lava or andesite, 2.43 g/cm3 for lava tuff and sand tuff, 2.5 g/cm3 for sandstone tuff and conglomerate tuff with clay stone inserted, and 2.7 g/cm3 for sand limestone and clay limestone. The result of this modelling is shown that there is fault around Muria mountain and is identified as Tempur and Rahwatu fault.

Abstrak: Pesisir utara Jepara dijadikan sebagai lokasi pengembangan PLTN Muria yang dipilih oleh pemerintah pusat melalui Badan Nuklir Nasional (Batan). Lokasi PLTN yang berada di Semenanjung Muria akan terkena dampak karena adanya aktivitas tektonik dan vulkanik di daerah tersebut, terutama di Gunung Muria. Penelitian ini menggunakan metode gravitasi untuk mengetahui struktur bawah permukaan di sekitar Gunung Muria. Data gravitasi yang diperoleh melalui https://topex.ucsd.edu/cgi-bin/get_data.cgi tersebar sebanyak 566 titik di Semenanjung Muria. Nilai anomali yang didapatkan direduksi dengan beberapa koreksi dan didapatkan nilai Anomali Bouguer Lengkap (CBA). Pemisahan anomali regional dan residual menggunakan Secong Vertical Derivative. Pemodelan bawah permukaan menggunakan metode pemodelan kedepan (Forward Modelling). Pada pemodelan ini didapatkan sebaran densitas batuan sebesar 2,4 g/cm3 (lava basalt atau andesit), 2,43 g/cm3 (tufaan, lahar dan tufaan pasiran), 2,5 g/cm3 (batu pasir tufaan dan konglomerat tufaan yang bersisipan batu lempung), dan 2,7 g/cm3 (batu gamping pasiran dan batu gamping lempungan). Hasil pemodelan menunjukkan adanya patahan di sekitar Gunung Muria dan diidentifikasikan sebagai patahan Tempur dan Rahtawu.

Keywords

Semenanjung Muria; Gunung Muria; Metode Gravitasi; Topex; Second Vertical Derivative

Full Text:

PDF

References

Astjario, P., & Kusnida, D. (2016). Penafsiran Struktur Geologi Semenanjung Muria Dari Data Citra Satelit. Jurnal Geologi Kelautan, 5(2), 63–71. https://doi.org/10.32693/jgk.5.2.2007.135

Blakely, R. J. (1995). Potential Theory in Gravity and Magnetic Applications. In Potential Theory in Gravity and Magnetic Applications. https://doi.org/10.1017/cbo9780511549816

BRONTO, S. (2006). Gunung api maar di Semenanjung Muria. Indonesian Journal on Geoscience, 2(1), 43–54. https://doi.org/10.17014/ijog.vol2no1.20074

Burger, H. R. (1992). Exploration geophysics of the shallow subsurface. New Jersey: Prentice Hall.

Chamoli, A., & Dimri, V. P. (2020). Spectral Analysis of Gravity Data of NW Himalaya. https://doi.org/10.3997/2214-4609-pdb.165.c_op_23

Dampney, C. N. G. (1969). The equivalent source technique. Geophysics. https://doi.org/10.1190/1.1439996

DiPietro, J. A. (2018). Normal Fault Systems. In Geology and Landscape Evolution. https://doi.org/10.1016/b978-0-12-811191-8.00018-x

Geophysics. In Cambridge University press. https://doi.org/10.5860/choice.48-1788

Grandis, H. (2009). Pengantar Pemodelan Inversi Geofisika. In Himpunan Ahli Geofisika Indonesia.

Hinze, W. J., Aiken, C., Brozena, J., Coakley, B., Dater, D., Flanagan, G., … Winester, D. (2005). New standards for reducing gravity data: The North American gravity database. Geophysics, 70(4), 25–32. https://doi.org/10.1190/1.1988183

IAEA. (2012). Volcanic Hazards in the Site Evaluation for Nuclear Installations. IAEA Safety Standards for Protecting People and the Environment, 1–128. Retrieved from http://www- ns.iaea.org/standards/%0Apapers3://publication/uuid/3F8F5DBE-F557-46E6-AD52- 9AEB88B76CDB

Indriana, R. D. (2019). Distribution of subsurface anomalies in the Muria Peninsula and depth analysis with euler deconvolution. International Journal of Physical Sciences and Engineering, 3(3), 21–30. https://doi.org/10.29332/ijpse.v3n3.355

Kusumadinata, K. (1979). Data Dasar Gunung Api Indonesia. Bandung: Direktorat Vulkanologi. Lowrie, W. (2007). Fundamentals of Geophysics, second edition. In Cambridge University

Press. https://doi.org/10.1017/CBO9780511807107

McBirney, A. R., Serva, L., Guerra, M., & Connor, C. B. (2003). Volcanic and seismic hazards at a proposed nuclear power site in central Java. Journal of Volcanology and Geothermal Research, 126(1–2), 11–30. https://doi.org/10.1016/S0377-0273(03)00114-8

Milsom, J., & Eriksen, A. (2011). Field Geophysics. In Field Geophysics. https://doi.org/10.1002/9780470972311

Nicholls, I. A., & Whitford, D. J. (1983). Potassium-rich volcanic rocks of the Muriah complex, Java, Indonesia: Products of multiple magma sources? Journal of Volcanology and Geothermal Research, 18(1–4), 337–359. https://doi.org/10.1016/0377-0273(83)90015-X

Octonovrilna, L., & Pudja, I. P. (2009). Analisa Perbandingan Anomali Gravitasi dengan Persebaran Intrusi Air Asin (Studi Kasus Jakarta 2006-2007). Jurnal Meteorologi Dan Geofisika. https://doi.org/10.31172/jmg.v10i1.32

Permata, I. (2012). Studi Komparasi Metode Filtering Untuk Pemisahan Anomali Regional danResidual dari Data Anomali Bouguer. Depok: Universitas Indonesia.

Purnomo, J., Koesuma, S., & Yunianto, M. (2016). Pemisahan Anomali Regional-Residual pada Metode Gravitasi Menggunakan Metode Moving Average, Polynomial dan Inversion. https://doi.org/10.13057/ijap.v3i01.1208

Reynolds, J. M. (1997). An introduction to applied and environmental geophysics. In An introduction to applied and environmental geophysics. https://doi.org/10.1071/pvv2011n155other

Sumintadireja, P., Dahrin, D., & Grandis, H. (2018). A note on the use of the second vertical derivative (SVD) of gravity data with reference to Indonesian cases. Journal of Engineering and Technological Sciences, 50(1), 127–139. https://doi.org/10.5614/j.eng.technol.sci.2018.50.1.9

Sunaryo. (1997). Panduan Praktikum Geofisika. Malang: Universitas Brawijaya. Telford, W. M., Geldart, L. P., & Sheriff, R. E. (1990). Applied Geophysics - Solid Earth

Terhadap Rencana Tapak Konstruksi Pltn. Jurnal Geologi Kelautan, 6(1). https://doi.org/10.32693/jgk.6.1.2008.145

Usman, E., & Lugra, W. (2016). Tinjauan Geologi Kelautan Perairan Semenanjung Muria

Van Bemmelen, R. W. (1949). The Geology of Indonesia. General Geology of Indonesia and Adjacent Archipelagoes. Government Printing Office, The Hague, pp. 545–547; 561–562. https://doi.org/10.1109/VR.2018.8447558

Wibowo, B., Mellawati, J., & Susiati, H. (2011). Kajian Evolusi Geokimia dan Kaitannya dengan Tingkat Bahaya Gunung Api Muria terhadap Tapak PLTN Muria. Jurnal Pengembangan Energi Nuklir.

Yanis, M., Marwan, M., & Ismail, N. (2019). Efficient Use of Satellite Gravity Anomalies for mapping the Great Sumatran Fault in Aceh Province. Indonesian Journal of Applied Physics, 9(02), 61. https://doi.org/10.13057/ijap.v9i2.34479

DOI: https://doi.org/10.20961/prosidingsnfa.v5i0.71829

Refbacks

  • There are currently no refbacks.