Warta Geologi, Vol. 51, No. 1, April 2025, pp. 18–28
Anju Goldmoreast Marbun, Edy Sutriyono, Ugi Kurnia Gusti*
Program Studi Teknik Geologi, Universitas Sriwijaya, Jalan Palembang-Prabumulih, KM 32 Inderalaya, Kabupaten Ogan Ilir, Sumatera Selatan 30662, Indonesia
* Corresponding author email address: ugikurnia@unsri.ac.id
Abstrak: Sumatera merupakan salah satu pulau di Indonesia yang dipengaruhi oleh kegiatan tektonik aktif, kerana dikawal oleh interaksi antara lempeng Indo-Australia dan Eurasia. Interaksi antara dua plat litosfera mengakibatkan kemunculan Barisan Orogeny, di mana kawasan lembangan dinaikkan dan sesar aktif dibangunkan di sepanjang pulau. Kajian ini mengkaji peranan Sesar Sumatera dan Sesar Mentawai yang bertanggungjawab terhadap evolusi Lembangan Bengkulu. Penilaian tertumpu pada analisis morfografi Sesar Sumatera (SF) Segmen Bengkulu dan Sesar Alas (AF) dengan pergerakan dip-slip di Renah Gajah Mati I dan sekitarnya di Kabupaten Seluma, Bengkulu. Parameter yang digunakan termasuk “lebar lantai lembah kepada nisbah ketinggian lembah (Vf), pemanjangan lembangan (Re), kamiran hipsometrik (HI), nisbah isipadu kepada kawasan (Rva), dan sinuositi hadapan gunung (Smf)”. Hasil analisis menunjukkan AF mempunyai nilai naik yang agak sederhana tinggi berdasarkan nilai plot indeks aktiviti tektonik (IAT) dan ini menunjukkan kawasan tersebut berpotensi terjejas oleh bahaya seismik.
Kata kunci: Tektonik, morfografi, indeks aktivas tektonik, Sesar Alas, Sesar Sumatera
Abstract: Sumatra is one of the islands in Indonesia that is affected by tectonic activitys, because it is controlled by the interaction between the Indo-Australian and Eurasian plates. The interaction between the two lithospheric plates resulted in the emergence of the Barisan Orogeny, where the basin area was uplifted, and active faults were developed along the island. This study examines the role of the Sumatran Fault System (SFS) and the Mentawai Alas Fault System which are responsible for the evolution of the Bengkulu Basin. The evaluation focused on geomorphic analysis of the Bengkulu Segment of the Sumatran Fault (SF) SFS and the Alas Fault (AF) with dip-slip movements in the Renah Gajah Mati and surrounding areas of Seluma Regency, Bengkulu. The parameters used include “valley floor width to valley height ratio (Vf), basin elongation (Re), hypsometric integral (HI), volume to area ratio (Rva), and mountain front sinuosity (Smf)”. The results of the analysis show that AF has a relatively medium-high uplift value based on the value of the index of tectonic activity (IAT) plot and this indicates that the area is potentially affected by seismic hazards.
Keywords: Tectonics, morphography, index of tectonic activity, Alas Fault, Sumatran Fault
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Manuscript received 19 March 2024;
Received in revised form 20 June 2024;
Accepted 31 January 2025
Available online 30 April 2025
DOI : https://doi.org/10.7186/wg511202503
0126-5539; 2682-7549 / Published by the Geological Society of Malaysia.
© 2025 by the Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC-BY) License 4.0
