Pendugaan Struktur Bawah Permukaan Gunung Merapi Berdasarkan Analisis Data Anomali Medan Gravitasi Citra Satelit

Uswatun Chasanah; Siti Diah Ayu Febriani; Eko Minarto

doi:10.20527/flux.v18i1.8456

Pendugaan Struktur Bawah Permukaan Gunung Merapi Berdasarkan Analisis Data Anomali Medan Gravitasi Citra Satelit

Uswatun Chasanah, Siti Diah Ayu Febriani, Eko Minarto

Abstract

ABSTRACT-Merapi Mount (2978 msl) is the higher active volcanoes in Indonesia, which is located between Sleman district, DI. Yogyakarta, and Magelang district, Boyolali district, Klaten district, Central Java. The eruption center of Merapi Mount is controlled by weak or unstable zone. This weak or unstable zone can be known from several lithologies of rock, which lies below Merapi Mount's surfaces through the density differences. One of the methods for determining the subsurface density in geophysics science is the gravity method. The gravity method is based on the difference in mass below the surface. This research aims to determine the distribution pattern lithology of Merapi Mount based on the density differences. Data processing in this research covers the entire process begins with a reading tool in field to obtain Bouguer anomaly's values at every point. To know the appearance below the Merapi Mount surface, creating some structure lithology modeling using software surfer 10 and Grav2DC. The result obtained in this research indicated that lithology below the surface of Merapi Mount. The variant of rocks density is between 2,256- 3,298 g.cm^-3. Most of them are sedimentary rock such as sandstone, granite, and basalt. Where the whole rocks an abundance of cold lava of Merapi Mount.

Keywords

Density, Gravity, Lithology, Merapi Mount

Full Text:

PDF (Bahasa Indonesia)

References

Ayu Wita Sari, & Suparta, G. B. (2018). Imaging of 3-D Seismic Tomography for Internal Structure Under the Mountain Merapi Using the Lotos-10 Software. Fisika Dan Aplikasinya, 3(2), 105.

Blakely, Richard J. (1995). Potential theory in Gravity and Magnetic Application. New York: Cambridge University Press.

Islamiyah, O. R. A., Minarto, E., & Santoso, A. B. (2019). Estimasi Kedalaman dan Perubahan Volume Sumber Tekanan Gunung Merapi Berdasarkan Pengamatan Data Tiltmeter. Jurnal Sains Dan Seni ITS, 7(2), 4–8. https://doi.org/10.12962/j23373520.v7i2.34024.

Jousset, P., Dwipa, S., Beauducel, F., Duquensnoy, T., Diament, M. (2000). Temporal gravity at Merapi during the 1993-1995 crisis: an insight into the dynamical behaviour of vaolcanoes. Journal of Volcanology and Geothermal Research 100, 289-320.

Kearey, P., Brooks, M., and Hill, I. (2009). An Introduction to Geophysical Exploration Third Edition. London: Blackwell Publishing.

Kiswiranti, D. (2013). Analisis Statistik Temporal Erupsi Gunungapi di Indonesia. Bimipa, 23(3), 211–217.

Rahman, M., & Susilo, A. (2014). Pendugaan Struktur Bawah Permukaan 2½ Dimensi di Kawasan Gunungapi Kelud Berdasarkan Survei Gravitasi. NATURAL B, 2(3), 221–228.

Reswara, A., & Sehah, P. A. (2014). Pendugaan Lapisan Reservoir Panas Bumi Di Kawasan Gunungapi Slamet Dengan Memanfaatkan Data Anomali Medan Gravitasi Citra Satelit. Berkala Fisika, 17(2), 45–54.

Sandwell, D. T., & Smith, W. H. F. (2009). Global marine gravity from retracked Geosat and ERS-1 altimetry: Ridge segmentation versus spreading rate. Journal of Geophysical Research: Solid Earth, 114(1), 1–18. https://doi.org/10.1029/2008JB006008

Sarkowi, M. (2010). Interpretasi Struktur Bawah Permukaan Daerah Gunung Merbabu-Merapi Berdasarkan Pemodelan 3D Anomali Bouguer. Berkala Fisika, 13(2), 11–18.

Suyanto, I. (2012). Pemodelan Bawah Permukaan Gunung Merapi Dari Analisis Data Magnetik Dengan Menggunakan Software Geosoft. Laporan Penelitian Prodi Geofisika Jurusan Fisika UGM, 1–48.

Telford, W. M., Geldart, L. P., & Sheriff, R. E. (1990). Chapter 2-Gravity Methods. In Applied Geophysics (pp. 6–61).

DOI: http://dx.doi.org/10.20527/flux.v18i1.8456