Claim Missing Document
Check
Articles

Found 6 Documents
Search

Erupsi Semeru 1 Desember 2020: Kronologi Kejadian Aliran Piroklastik, Kondisi Pre-Eruptif, dan Laju Ekstrusi Material Volkanik Banggur, Wilfridus F S; Nareswari, Ratika Benita; Saina, Nazirah; Astyka Pamumpuni; Mirzam Abdurrachman; Estu Kriswati; Liswanto; Mukdas Sofian; Yadi Yuliandi; Kristianto; Sofyan Primulyana; Idham Andri Kurniawan
Jurnal Geologi dan Sumberdaya Mineral Vol. 25 No. 3 (2024): JURNAL GEOLOGI DAN SUMBERDAYA MINERAL
Publisher : Pusat Survei Geologi

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33332/jgsm.geologi.v25i3.796

Abstract

Semeru merupakan gunungapi paling aktif di Jawa dengan tipe erupsi strombolian-vulkanian yang disertai pertumbuhan kubah lava. Erupsi eksplosif Semeru dapat menghasilkan guguran lava pijar dan runtuhan kubah lava yang disertai aliran piroklastik dengan jarak luncur mencapai 5-12 km ke arah selatan (Besuk Kembar dan Besuk Bang) atau tenggara (Besuk Kobokan) dari pusat erupsi. Pada 1 Desember 2020, terjadi aliran piroklastik dengan jarak luncur 11.5 km, yang merupakan jarak luncur terjauh sejak erupsi 2002. Rekonstruksi terhadap kronologi kejadian dan sebaran endapan aliran piroklastik 1 Desember 2020 secara detil dilakukan menggunakan data CCTV, press release, citra satelit, foto drone, portal berita, dan kanal media sosial. Kondisi pre-eruptif jangka pendek dikaji menggunakan citra satelit SAR Sentinel-1, Sentinel-2 dari MIROVA, dan frekuensi kegempaan. Algoritma MODVOLC digunakan untuk mengkaji laju ekstrusi produk material volkanik sebagai gambaran kondisi pre-eruptif jangka panjang. Rekonstruksi kejadian aliran piroklastik menunjukkan bahwa erupsi dimulai dengan guguran lava yang diikuti awan panas dengan beberapa perulangan dan kekuatan yang meningkat. Kondisi pre-eruptif sepanjang tahun 2020 menunjukkan perubahan morfologi bukaan kawah pusat, posisi titik runtuh guguran lava, serta posisi akumulasi material guguran di sekitar puncak yang menyebabkan arah luncuran aliran piroklastik lebih mengarah ke Besuk Kobokan. Sementara itu, peningkatan akumulasi volume dan laju ekstrusi material volkanik mengindikasikan kemungkinan peningkatan jarak luncuran ke depannya.
Segmentation of the Active Fault on the Cirebon-Semarang Segments as Revealed by DEM-Derived Geomorphic Indices Jannah, Miftahul; Pamumpuni, Astyka; Sadisun, Imam Achmad
Journal of Geoscience, Engineering, Environment, and Technology Vol. 9 No. 04 (2024): JGEET Vol 09 No 04 : December (2024)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25299/jgeet.2024.9.04.15572

Abstract

This research focuses on the segmentation and tectonic activity of the Baribis-Kendeng Fault across the Cirebon to Semarang segments, revealed through the analysis of geomorphic indices derived from Digital Elevation Models (DEM). Utilizing geomorphic indices such as the Hypsometric Integral (HI), Stream Length-Gradient Index (SL), and SL/K ratio, the analysis was conducted on 33 streams crossing ten segments. The results indicate that the landscape in the research area is predominantly in the youthful stage, with HI values ranging from 0.459 to 0.492, indicating active tectonic uplift. Segments such as Ungaran and Pemalang exhibit significant tectonic activity, with high SL/K values, particularly in the Ungaran segment, where the SL/K value reaches 344.872. These findings suggest that fault activity in the region is ongoing, with stronger uplift patterns observed at the western and eastern ends of the fault, while relatively lower activity is found in the central area. This research highlights the ongoin tectonic processes shaping the region’s geomorphology and contributes to a better understanding of the active fault system in Java Island.
GEOMORFOLOGI SESAR AKTIF DI PULAU RUMBERPON, PAPUA Pamumpuni, Astyka; Sapiie, Benyamin; Ipranta, Ipranta; Sadisun, Imam Achmad
Bulletin of Geology Vol 6 No 1 (2022): Bulletin of Geology
Publisher : Fakultas Ilmu dan Teknologi Kebumian (FITB), Institut Teknologi Bandung (ITB)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/bull.geol.2022.6.1.4

Abstract

Morfologi di bagian Leher Burung, Papua didominasi oleh bentuk morfologi sesar naik dan lipatan. Morfologi yang menunjukkan lipatan ideal yang masih muda, bentukan antiform merepresentasikan antiklin. Namun demikian, data kegempaan di daerah Leher Burung, Papua menunjukkan banyaknya gempa dengan mekanisme sesar normal dan sesar mendatar.Observasi geomorfologi di lokasi Leher Burung, di Pulau Rumberpon dilakukan pada studi ini dengan menggunakan data DEM (digital elevation model) dengan resolusi 8m dari DEMNAS (digital elevation modelnasional). Analisis geomorfologi ditekankan pada identifikasi sesar aktif. Data kegempaan yang berupa lokasi gempa (epicenter dan hipocenter), magnitudo, dan waktu kejadian didapatkan dari katalog kegempaan yang telah direlokasi. Mekanisme fokal gempa didapatkan dari katalog CMT (centroid moment tensor). Data kegempaan digunakan untuk melihat hubungan data kegempaan dan hasil analisis geomorfologi.Hasil analisis geomorfologi menunjukkan adanya sesar normal yang aktif berkorelasi dengan arah jurus dari mekanisme fokal yang ada di area ini. Observasi menunjukkan adanya bukti-bukti sesar normal dengan arah jurus utara-selatan (N-S) dan timur laut-barat daya (NE-SW). Fitur-fitur geomorfologi yang terpetakan antara lain adalah laguna yang memanjang, lembah paralel, penampang topografi yang menunjukkan seri rangkaian sesar normal, gawir sesar, dan relay-ramp. Fitur geomorfologi yang ada menunjukkan adanya seri sesar normal aktif memiliki kemiringan ke barat dengan jurus ke utara-selatan sesuai dengan arah jurus dari mekanisme fokal kegempaan yang ada. Kesesuaian antara mekanisme fokal gempa dan bukti morfologi menunjukkan adanya sesar normal aktif di area Leher Burung, terutama di Pulau Rumberpon. Mekanisme pembentukan sesar di Pulau Rumberpon ini terkait erat dengan Sesar Yapen-Sorong dan adanya pembelokan ke kanan zona sesar tersebut. Kata kunci: geomorfologi, sesar normal, Papua, sesar aktif
Community-based Landscape Planning in Kampong Batu Lonceng within Lembang Faults Mitigation Framework Rani, Medria Shekar; Purwaningrum, Rr Diah Asih; Faisal, Budi; Dahlan, Mohammad Zaini; Martokusumo, Widjaja; Purwaningsih, Rr Diah Asih; Rahmy, Widyastri Atsary; Binta, Izaza; Pamumpuni, Astyka; Meilano, Irwan; Kobayashi, Hirohide; Shibata, Shozo
Jurnal Lanskap Indonesia Vol. 17 No. 2 (2025): Jurnal Lanskap Indonesia
Publisher : http://arl-faperta.ipb.ac.id/

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29244/jli.v17i2.62922

Abstract

Lembang Fault is one of the active faults produced by the subducted Indo-Australian plate beneath the Eurasian plate along Java Island. It has a high potential for hazard due to its proximity to densely populated areas, including Kampong Batu Lonceng, located approximately 150 meters from the fault. This paper explores the interplay between philosophical beliefs, emotional attachment to the land, natural hazards, land availability for relocation, and applicable regulations in Kampong Batu Lonceng. A three-phase landscape planning regarding the Kampong settlement disaster mitigation was proposed based on data collected from the community stakeholders through field surveys, initial interviews, and discussion. The first phase proposed that the community stays in the existing area with minor preventive developments. The second phase proposed that the community moves across the river and move further to a new, safer location in the third phase. The first phase is the most reasonable since the community does not have to move to another location but needs to revitalize the forest. The second and third phases can only be pursued when the community understands the potential disaster of the fault. Moreover, the third phase requires that the government provide a safer zone for the community to relocate. Another discussion with the community stakeholders shows an agreement towards the first and the third phases and a reluctance over the second phase. However, although many regulations have already taken place formally, enforcing them towards implementation in a traditional community needs to be handled very carefully.
Geology and Identification of Freshwater Sources Using Water Resistivity Survey in Landu Village, Rote Ndao, East Nusa Tenggara, Indonesia Gunawan, Indra; Rudyawan, Alfend; Pamumpuni, Astyka; Handayani, Alfita Puspa; Hadiana, Meli; Sapiie, Benyamin; Febrianti, Adinda
Journal of Geoscience, Engineering, Environment, and Technology Vol. 10 No. 02 (2025): JGEET Vol 10 No 02 : June (2025)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25299/jgeet.2025.10.02.21729

Abstract

Located within the tectonically complex Banda Arc of eastern Indonesia, Landu Island, in Rote Ndao, East Nusa Tenggara provides a unique setting to investigate the relationship between arc-continent collision, karst development, and groundwater dynamics. The island is primarily underlain by Quaternary limestones, which form the principal aquifer system. Despite this hydrogeological potential, Landu faces acute freshwater shortages, particularly during the dry season. This study combines geological field mapping with a 1D electrical resistivity survey to characterize subsurface lithology, identify groundwater-bearing units, and assess the extent of seawater intrusion. The geological survey reveals slightly southward-tilted, fossiliferous limestones that exhibit clear evidence of karstification, indicating a history of tectonic uplift and surface water infiltration. A freshwater spring—currently the main source of potable water for the local population—was documented in the southeastern part of the island, with a total dissolved solids (TDS) concentration of 924 ppm, suggesting moderate water quality. Resistivity modeling identifies two potential aquifers: a shallow zone at depths of 5.2–17.2 m, and a more extensive, deeper reservoir between 35.1–92.1 m. The shallow aquifer shows lower resistivity values, indicative of possible saltwater mixing, which correlates with historical reports of failed boreholes in this zone. In contrast, the deeper aquifer exhibits higher resistivity signatures, suggesting better preservation of freshwater and greater potential for sustainable extraction. These findings highlight the critical influence of structural controls and karst processes on groundwater storage and quality. The study emphasizes the need for careful aquifer targeting and protection measures to prevent saltwater intrusion. Future work should focus on high-resolution geophysical imaging and long-term monitoring to support resilient water resource management on Landu Island.
Quantifying the Effect of Natural Consolidation and Fluid Discharge on Land Subsidence of the Sidoarjo Mud Volcano, East Java, Indonesia Bayuaji, Giri; Saepuloh, Asep; Pamumpuni , Astyka; Dedy Wijnarko; Maryudhaningrum, Santika Tristi
Journal of Geoscience, Engineering, Environment, and Technology Vol. 11 No. 02 (2026): JGEET Vol 11 No 02 : June (2026)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25299/jgeet.2026.11.02.21930

Abstract

Land subsidence in the Sidoarjo Mud Volcano (SMV) area has been widely recognized as a consequence of sustained mud discharge and progressive subsurface consolidation. Earlier geodetic studies using GPS and InSAR, combined with geological and geomechanical investigations, have demonstrated persistent long‑term ground deformation, widespread flooding, and severe infrastructure damage linked to these processes. This study aims to (1) quantify spatial and temporal subsidence rates, (2) identify the dominant controlling mechanisms, and (3) estimate the relative contributions of fluid discharge and natural consolidation to total subsidence. Surface deformation was derived through time‑series analysis of Sentinel‑1A SAR data using the pair‑wise logic technique differential interferometric synthetic aperture radar (PLT‑D‑InSAR). These results were integrated with one‑dimensional (1D) consolidation modeling based on lithological coring data and mud discharge records. The PLT‑D‑InSAR analysis successfully captured detailed subsidence patterns over a wide area and shows good agreement with GPS observations (R² ≈ 0.82). The combined D‑InSAR, consolidation, and discharge analysis reveals a very strong correlation (R² ≈ 0.97), indicating that subsidence is mainly governed by fluid discharge and consolidation processes. Fluid discharge accounts for approximately 72.2% of the total subsidence, while natural consolidation contributes about 16.5%. The highest subsidence rates are concentrated near the mudflow center and are structurally influenced by the Watukosek and Siring faults. These findings highlight the dominant role of discharge‑induced deformation and provide important constraints for long‑term hazard assessment and land‑use planning in the SMV region.