Kabupaten Kepahiang merupakan salah satu daerah yang berada di ring of fire Pacific sehingga memiliki potensi geothermal yang cukup potensial untuk menghasilkan energi terbarukan agar dapat dipergunakan untuk daya penyuplai listrik. Penelitian ini bertujuan untuk memetakan pola sebaran anomali magnetik daerah yang diduga sebagai distribusi dan reservoir panas bumi Kepahiang secara menyeluruh. Penelitian ini menggunakan Proton Precission Magnetometer (PPM) yang tersebar di 143 titik pengukuran. Nilai anomali total yang tinggi dari hasil pengukuran dominan berada di bagian timur, tenggara, selatan, barat daya dan barat daerah penelitian dengan nilai 0 nT sampai 1500 nT, sedangkan pada bagian barat laut, utara dan timur laut di dominasianomali total rendah dengan nilai 0 nT sampai -1500 nT. Pada peta sebaran intensitas anomali magnetik total dominan bernilai rendah dengan nilai 0 nT sampai -1500 nT yang berarti daerah tersebut dipengaruhi oleh panas bumi. Sedangkan nilai anomali magnetik di sekitar Sesar Musi dominan tidak dipengaruhi oleh panas bumi karena bernilai tinggi yaitu 0 nT sampai 600 nT. Pada daaerah mata air panas sumber aliran berasal dari barat laut dengan nilai 0 nT sampai 300 nT

Bengkulu Province is the converging path region between the Indo-Australian − Eurasian tectonic plates in the ocean and the Sumatran fault crossing on the mainland. The condition implies that the sliding force of the slab is easy to trigger fractures and to cause the material to be relatively less elastic, resulting in high seismic intensity. This study aims to identify areas with the potential for landslides and its mapping, and to analyze the factors that cause landslides in Central Bengkulu Regency, Bengkulu Province, Indonesia. This study was conducted using rock physical parameters of ground shear strain (GSS) which were correlated with parameters of slope, slope height, Vs 30 value, fault distance to measurement point, rock conditions, rainfall, and PGA value. Furthermore, these parameters were overlaid thoroughly by the statistical method of the Analytical Hierarchy Process (AHP). Data acquisition is divided into two stages, namely the secondary data collection stage and the field survey stage. Secondary data collection was carried out to support the creation of landslide potential maps, analysis, and field survey data input. Secondary data is the value of Vs 30 , the distance of the fault to the measurement point, rainfall, and the PGA value. Field survey data are in the form of GSS values, slope, slope height, and rock conditions. The results of this study are identified areas that have the category of high, medium, and low landslide potential. Based on the calculated parameters, the GSS parameter is the most dominant which affects the landslide potential in the studied area.

<p class="AbstractText">Bengkulu City is located in the subduction zone of the Indo-Australian and Eurasian plates, so it is prone to earthquake. To anticipate the impact of earthquake, disaster mitigation can be carried out, one of which is a study of the level of rock hardness in the area. This study aims to determine the level of rock hardness based on seismic wave velocity in several rock formations and to determine which rock formations have the potential to cause vulnerability to earthquakes. Field data acquisition uses the seismic refraction method with time-term inversion technique. The data obtained in the field are processed to obtain a 2-D cross-section of the subsurface seismic wave velocity values. The study results show that the level of rock hardness depends on the type of rock formation. The Andesite Rock Formation Unit (Tpan) has the highest level of hardness, while the transitional area between the Alluvium Rock Formation Unit (Qa) and the Swamp Sedimentary Rock Formation Unit (Qs) has the lowest level of hardness.</p>

ABSTRAK-Kota Bengkulu merupakan daerah yang sangat rawan terhadap ancaman gempabumi. Salah satu upaya mengurangi dampak bencana gempabumi adalah melakukan analisis potensi tersebut berdasarkan data mikrotremor dan metode pembobotan statistik. Penelitian ini bertujuan memetakan dan menganalisis daerah-daerah yang rentan mengalami ancaman bahaya gempabumi. Penelitian ini dilakukan menggunakan data sekunder dan survei lapangan. Data sekunder bersumber dari penelitian-penelitian terkait, sedangkan data survei lapangan berupa data mikrotremor menggunakan metode Horizontal to Vertical Spectral Ratio (HVSR). Alat yang digunakan untuk survei lapangan berupa broadband seismometer PASI Gemini-2 triaxial geophone dengan natural freq. 2 Hz ± 10%, berat 2 kg (s.n.: 12/004). Akusisi data lapangan dilakukan selama 30 menit (360.000 samples) per titik pengukuran dengan sampling rate 5 ms (200 Hz). Selanjutnya, tumpangsusun hasil pengolahan data sekunder dan lapangan menggunakan metode pembobotan statistik Analytical Hierarchy Process (AHP), sehingga diperoleh peta potensi kerentanan gempabumi di wilayah studi. Berdasarkan hasil analisis yang ditunjukkan dalam peta kerentanan gempabumi di daerah Kota Bengkulu dalam penelitian ini, Kecamatan Gading Cempaka, Kecamatan Singaranpati, Kecamatan Selebar, sebagian kecil Kecamatan Ratu Agung, dan Kecamatan Muara Bangkahulu adalah daerah yang mempunyai potensi kegempaan tinggi, sedangkan Kecamatan Selebar adalah daerah yang mempunyai potensi kegempaan rendah. Oleh karena itu untuk daerah berisiko tinggi perlu lebih diwaspadai dan perlu perencanaan pembangunan yang mengacu kepada standar risiko bencana.

Shear wave velocity <em>(V_s)</em> structure at along of Central Bengkulu-Kepahiang crossline has been mapped. This research aims to identify the subsurface structure and to estimate the constituent material type of rock in landslide-prone areas (Central Bengkulu-Kepahiang crossline). Shear wave velocity structure on each site is obtained by the HVSR-inversion of 146 microtremor data (ambient noise recording of seismometer). <em>V_s</em> structure at the line mapped from the surface until to 30 meters of the depth. Groups of Vs are identified in class E (<em>V_s</em> &lt;180), Class D (180≤<em> V_s</em> &lt;360), Class C (360≤<em> V_s</em> &lt;760), and Class B (760≤<em> V_s</em> &lt;1500). The subsurface structure at the depth of 0 to 10 meters are dominated by stiff soil, very dense soil, and soft rock which has highly fractured and weathered rock properties. At the depth of 15 meters to 30 meters, the subsurface structure is dominated by hard rock but it is high potential or easy to fracturing and weathering like the properties of the rocks in areas that have landslides in the past. Based on <em>V_s</em> value, rock constituent materials are deposition of sand, clay, gravel and alluvium ranging from soft to relatively hard structures at the depth.