Vol. 12 No. 3 (2026): In Progress
Open Access
Peer Reviewed

Seismic Characteristics of Mount Agung during the October–November 2017 Period

Authors

W.T. Baskoro , I.K. Putra , N.N. Wendri , I.N. Artawan , V.C.W. Putri , S. Sismanto

DOI:

10.29303/jppipa.v12i3.13893

Published:

2026-03-25

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Abstract

Mount Agung, a prominent stratovolcano in Bali, Indonesia, exhibited a significant increase in volcanic activity between October and November 2017 after 54 years of dormancy. This study investigates the seismic characteristics of this unrest period using waveform and spectral analysis of data from three monitoring stations: Abang (ABNG), Cegi (CEGI), and Yeh Kori (YHKR). The results indicate that seismicity was dominated by intermediate-to-deep volcanic earthquakes (VA and VB types), reaching a peak on October 18, 2017, with 679 VA and 266 VB events recorded. Spectral analysis through Fast Fourier Transform (FFT) revealed dominant frequencies ranging from 3.8 to 10.1 Hz, representing brittle failure mechanisms within the rigid volcanic edifice. A critical transition was observed in late November, where discrete high-frequency events declined and were replaced by continuous volcanic tremors, signaling a shift from a closed to an open magmatic system. This "seismic lull" accompanied by tremor signals, indicates the establishment of a stable conduit, facilitating magma migration toward the surface. These findings underscore the importance of spectral characteristics and event-type transitions as vital precursors for eruptive forecasting and volcanic hazard mitigation.

Keywords:

2017 Eruption Fast fourier transform (FFT) Mount agung Spectral analysis VA and VB earthquakes

References

Abidin, H. Z., Andreas, H., Meilano, I., Gamal, M., Gumilar, I., & Abdullah, C. I. (2009). Deformasi Koseismik dan Pascaseismik Gempa Yogyakarta 2006 dari Hasil Survei GPS. Indonesian Journal on Geoscience, 4(4), 275–284. https://doi.org/10.17014/ijog.4.4.275-284 DOI: https://doi.org/10.17014/ijog.4.4.275-284

Albino, F., Biggs, J., & Syahbana, D. K. (2019). Dyke intrusion between neighbouring arc volcanoes responsible for 2017 pre-eruptive seismic swarm at Agung. Nature Communications, 10(1), 748. https://doi.org/10.1038/s41467-019-08564-9 DOI: https://doi.org/10.1038/s41467-019-08564-9

Andreastuti, S., Paripurno, E., Gunawan, H., Budianto, A., Syahbana, D., & Pallister, J. (2019). Character of community response to volcanic crises at Sinabung and Kelud volcanoes. Journal of Volcanology and Geothermal Research, 382(2), 298–310. https://doi.org/10.1016/j.jvolgeores.2017.01.022 DOI: https://doi.org/10.1016/j.jvolgeores.2017.01.022

Arisalwadi, M., Maryanto, S., & Triastuty, H. (2017). Analisis Spektral dan Waveform Cross Correlation Tremor Vulkanik Gunungapi Bromo Jawa Timur Pada Letusan Tahun 2016. Natural B, 4(1), 57–64. Retrieved from https://natural-b.ub.ac.id/index.php/natural-b/article/download/388/pdf DOI: https://doi.org/10.21776/ub.natural-b.2017.004.01.8

Brigham, E. O. (1988). The fast Fourier transform and its applications. Prentice Hall.

Caudron, C., Syahbana, D. K., Lecocq, T., Van Hinsberg, V., McCausland, W., Triantafyllou, A., Camelbeeck, T., Bernard, A., & Surono. (2015). Kawah Ijen volcanic activity: a review. Bulletin of Volcanology, 77(3), 16. https://doi.org/10.1007/s00445-014-0885-8 DOI: https://doi.org/10.1007/s00445-014-0885-8

Cho, Y. H., Caleon, I. S., & Kapur, M. (2015). Authentic Problem Solving and Learning in the 21st Century. Springer Singapore. https://doi.org/10.1007/978-981-287-521-1 DOI: https://doi.org/10.1007/978-981-287-521-1

Freret-Lorgeril, V., Bonadonna, C., Corradini, S., Guerrieri, L., Lemus, J., Donnadieu, F., Scollo, S., Gurioli, L., & Rossi, E. (2022). Tephra characterization and multi-disciplinary determination of Eruptive Source Parameters of a weak paroxysm at Mount Etna (Italy). Journal of Volcanology and Geothermal Research, 421. https://doi.org/10.1016/j.jvolgeores.2021.107431 DOI: https://doi.org/10.1016/j.jvolgeores.2021.107431

Fridayanti, D. E. (2022). Analisis Gempa Vulkanik Gunung Merapi Dan Korelasi Terhadap Pengukuran Infrasonik. Universitas Islam Negeri Maulana Malik Ibrahim.

Gile, W. W. (1974). A Mercury Pendulum Seismometer. Geophysical Journal International, 36(1), 153–165. https://doi.org/10.1111/j.1365-246X.1974.tb03630.x DOI: https://doi.org/10.1111/j.1365-246X.1974.tb03630.x

Iguchi, M. (2025). Integrated Research on Large-Scale Eruption at Sakurajima Volcano. Journal of Disaster Research, 20(2), 186–196. https://doi.org/10.20965/jdr.2025.p0186 DOI: https://doi.org/10.20965/jdr.2025.p0186

Kriswati, E., Meilano, I., Hasib, M., Saepuloh, A., Kuncoro, H., Dewanto, B. G., & Fuadi, A. (2024). Explosion mechanism and volume estimation of volcanic ash during the eruption of Sinabung Volcano on February 19, 2018: Insight from kinematic GPS and seismic data. Journal of Volcanology and Geothermal Research, 447(1), 108034. https://doi.org/10.1016/j.jvolgeores.2024.108034 DOI: https://doi.org/10.1016/j.jvolgeores.2024.108034

Lahr, J. C., Chouet, B. A., Stephens, C. D., Power, J. A., & Page, R. A. (1994). Earthquake classification, location, and error analysis in a volcanic environment: implications for the magmatic system of the 1989–1990 eruptions at redoubt volcano, Alaska. Journal of Volcanology and Geothermal Research, 62(1–4), 137–151. https://doi.org/10.1016/0377-0273(94)90031-0 DOI: https://doi.org/10.1016/0377-0273(94)90031-0

Lowenstern, J. B., Wallace, K., Barsotti, S., Sandri, L., Stovall, W., Bernard, B., Privitera, E., Komorowski, J. C., Fournier, N., Balagizi, C., & Garaebiti, E. (2022). Guidelines for volcano-observatory operations during crises: recommendations from the 2019 volcano observatory best practices meeting. Journal of Applied Volcanology, 11(1). https://doi.org/10.1186/s13617-021-00112-9 DOI: https://doi.org/10.1186/s13617-021-00112-9

McCausland, W. A., Gunawan, H., White, R. A., Indrastuti, N., Patria, C., Suparman, Y., Putra, A., Triastuty, H., & Hendrasto, M. (2019). Using a process-based model of pre-eruptive seismic patterns to forecast evolving eruptive styles at Sinabung Volcano, Indonesia. Journal of Volcanology and Geothermal Research, 382, 253–266. https://doi.org/10.1016/j.jvolgeores.2017.04.004 DOI: https://doi.org/10.1016/j.jvolgeores.2017.04.004

McNutt, S. R., & Roman, D. C. (2015). Volcanic Seismicity. In The Encyclopedia of Volcanoes (pp. 1011–1034). Elsevier. https://doi.org/10.1016/B978-0-12-385938-9.00059-6 DOI: https://doi.org/10.1016/B978-0-12-385938-9.00059-6

Minakami, T. (1974). Seismology of Volcanoes in Japan (pp. 1–27). https://doi.org/10.1016/B978-0-444-41141-9.50007-3 DOI: https://doi.org/10.1016/B978-0-444-41141-9.50007-3

Muslim, D., Sadisun, I., Nugraha, A. D., & Sekretariat, S. (2019). Vulkanologi dan Bencana. Kementerian Energi Dan Sumber Daya Mineral Republik Indonesia Badan Geologi.

Nugraini, L. D. A., & Safitri, D. A. (2023). Analisis Deformasi Gunung Agung Berdasarkan Data Citra SAR Sentinel-1A dan Metode D-InSAR. Jurnal Ilmiah Geologi PANGEA, 9(1sp), 28. https://doi.org/10.31315/jigp.v9i1sp.9407 DOI: https://doi.org/10.31315/jigp.v9i1sp.9407

Nugroho, H., Widiyantoro, S., & Ibrahim, G. (2014). Penentuan Posisi Hiposenter Gempabumi dengan Menggunakan Metoda Guided Grid Search dan Model Struktur Kecepatan Tiga Dimensi. Jurnal Meteorologi Dan Geofisika, 8(1), 48–60. https://doi.org/10.31172/jmg.v8i1.3 DOI: https://doi.org/10.31172/jmg.v8i1.3

Octavia, D., Suharti, S., Murniati, Dharmawan, I. W. S., Nugroho, H. Y. S. H., Supriyanto, B., Rohadi, D., Njurumana, G. N., Yeny, I., Hani, A., Mindawati, N., Suratman, Adalina, Y., Prameswari, D., Hadi, E. E. W., & Ekawati, S. (2022). Mainstreaming Smart Agroforestry for Social Forestry Implementation to Support Sustainable Development Goals in Indonesia: A Review. Sustainability, 14(15), 9313. https://doi.org/10.3390/su14159313 DOI: https://doi.org/10.3390/su14159313

Parwita, I. G. L. M., Mudhina, M., INTARA, I. W., & SUDIASA, I. W. (2019). Evaluasi Teknis Kinerja Bangunan Pengendali Lahar Tukad Unda Pasca Erupsi Gunung Agung Tahun 2017. Construction and Material Journal, 1(1), 53–67. https://doi.org/10.32722/cmj.v1i1.1330 DOI: https://doi.org/10.32722/cmj.v1i1.1330

Pranata, B., Yudistira, T., Widiyantoro, S., Brahmantyo, B., Cummins, P. R., Saygin, E., Zulfakriza, Z., Rosalia, S., & Cipta, A. (2019). Shear wave velocity structure beneath Bandung basin, West Java, Indonesia from ambient noise tomography. Geophysical Journal International, 225(3), 1850–1865. https://doi.org/10.1093/gji/ggz493 DOI: https://doi.org/10.1093/gji/ggz493

Pritaningtyas, A. D., Hasib, M., Kriswati, E., Indrastuti, N., & Zera, T. (2023). Analyses of explosion earthquakes at Sinabung Volcano: characteristics of waveform, spectra, and energy. IOP Conference Series: Earth and Environmental Science, 1227(1), 012028. https://doi.org/10.1088/1755-1315/1227/1/012028 DOI: https://doi.org/10.1088/1755-1315/1227/1/012028

Sahara, D. P., Rahsetyo, P. P., Nugraha, A. D., Syahbana, D. K., Widiyantoro, S., Zulfakriza, Z., Ardianto, A., Baskara, A. W., Rosalia, S., Martanto, M., & Afif, H. (2021). Use of Local Seismic Network in Analysis of Volcano-Tectonic (VT) Events Preceding the 2017 Agung Volcano Eruption (Bali, Indonesia). Frontiers in Earth Science, 9(1), 12034. https://doi.org/10.3389/feart.2021.619801

Suparman, Y., Syahbana, D. K., & Andreas, A. S. (2019). Seismic Velocity Changes Associated with The 2017-2018 Activity of Mount Agung, Bali as Inferred from Cross-correlations of Ambient Seismic Noise (A Preliminary Result). https://doi.org/10.13140/RG.2.2.18249.08806

Syahbana, D. K., Kasbani, K., Suantika, G., Prambada, O., Andreas, A. S., Saing, U. B., Kunrat, S. L., Andreastuti, S., Martanto, M., Kriswati, E., Suparman, Y., Humaida, H., Ogburn, S., Kelly, P. J., Wellik, J., Wright, H. M. N., Pesicek, J. D., Wessels, R., Kern, C., … Lowenstern, J. B. (2019). The 2017–19 activity at Mount Agung in Bali (Indonesia): Intense unrest, monitoring, crisis response, evacuation, and eruption. Scientific Reports, 9(1). https://doi.org/10.1038/s41598-019-45295-9 DOI: https://doi.org/10.1038/s41598-019-45295-9

Wassermann, J. (2011). Volcano Seismology. https://doi.org/10.2312/GFZ.NMSOP-2_ch13

Wright, H. M. N., Pallister, J. S., McCausland, W. A., Griswold, J. P., Andreastuti, S., Budianto, A., Primulyana, S., Gunawan, H., Battaglia, M., Diefenbach, A., Griswold, J., Ewert, J., Kelly, P., Kern, C., LaFevers, M., Lockhart, A., Marso, J., Mayberry, G., McCausland, W., … Triastuty, H. (2019). Construction of probabilistic event trees for eruption forecasting at Sinabung volcano, Indonesia 2013–14. Journal of Volcanology and Geothermal Research, 382(4), 233–252. https://doi.org/10.1016/j.jvolgeores.2018.02.003 DOI: https://doi.org/10.1016/j.jvolgeores.2018.02.003

Zulfakriza, Z., Nugraha, A. D., Widiyantoro, S., Cummins, P. R., Sahara, D. P., Rosalia, S., Priyono, A., Kasbani, K., Syahbana, D. K., Priambodo, I. C., Martanto, M., Ardianto, A., Husni, Y. M., Lesmana, A., Kusumawati, D., & Prabowo, B. S. (2020). Tomographic Imaging of the Agung-Batur Volcano Complex, Bali, Indonesia, From the Ambient Seismic Noise Field. Frontiers in Earth Science, 8. https://doi.org/10.3389/feart.2020.00043 DOI: https://doi.org/10.3389/feart.2020.00043

Author Biographies

W.T. Baskoro, Universitas Udayana

Author Origin : Indonesia

I.K. Putra, Universitas Udayana

Author Origin : Indonesia

N.N. Wendri, Universitas Udayana

Author Origin : Indonesia

I.N. Artawan, Universitas Udayana

Author Origin : Indonesia

V.C.W. Putri, Universitas Udayana

Author Origin : Indonesia

S. Sismanto, Universitas Gadjah Mada

Author Origin : Indonesia

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How to Cite

Baskoro, W., Putra, I., Wendri, N., Artawan, I., Putri, V., & Sismanto, S. (2026). Seismic Characteristics of Mount Agung during the October–November 2017 Period. Jurnal Penelitian Pendidikan IPA, 12(3), 313–322. https://doi.org/10.29303/jppipa.v12i3.13893