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Hydrogeochemistry of Natar and Cisarua Hot springs in South Lampung, Indonesia Mochamad Iqbal; Bella Restu Juliarka; Wijayanti Ashuri; Bilal Al Farishi
Journal of Geoscience, Engineering, Environment, and Technology Vol. 4 No. 3 (2019): JGEET Vol 04 No 03 : September (2019)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (915.598 KB) | DOI: 10.25299/jgeet.2019.4.3.4070

Abstract

Natar Hot Spring is one of the geothermal manifestations that is located in Lampung Province, Indonesia. About 6 km to the east, another hot spring appears with temperature around 40°C with neutral pH called Cisarua Hot Spring. The Natar Hot Spring itself having temperature 47-54°C with 6.23 pH. Based on the geologic map, the appearance of these hot spring is caused by Lampung-Panjang Fault which trending northwest-southeast. Morphology of the research area is showing a flat terrain topography which composed of Quaternary volcanic rock and metamorphic rock in the basement. The nearest volcano that expected to be the heat source of the geothermal system is the Quaternary extinct volcano called Mt. Betung which is located about 15 km to the southwest. The aim of the study is to analyze the geochemistry of the manifestations and calculate the reservoir temperature. Geochemistry analysis result shows both manifestations are bicarbonate which is formed as a steam-heated water or steam condensates. Geothermometer calculation shows that the geothermal reservoir has temperature 150-160°C with approximately 300 m in depth. All manifestations are originated from meteoric water according to stable isotope analysis D and δ18O data and interacting with carbonate-metamorphic rock beneath the surface based on 13C isotope value. A further geophysics study is needed to determine where the heat comes from.
Analisis Aliran Air Bawah Permukaan Dengan Menggunakan Metode Geolistrik Muhammad Ragil Setiawan; Bilal Al Farishi; Lea Kristi Agustin
Jurnal Pendidikan Teknologi Kejuruan Vol 2 No 4 (2019): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (837.239 KB) | DOI: 10.24036/jptk.v2i4.6323

Abstract

Cean water is needed in a human community. The need for clean water can be taken from subsurface water through a pumping process. Efforts to get clean water that has sustainability can be done by knowing the direction of the aquifer flow. The direction of the aquifer flow can be known through subsurface modeling. This study uses the geoelectric method in modeling the subsurface layer to determine the position of the aquifer. Based on the subsurface model, the average depth of an aquifer is between 30-100 meters. The subsurface model shows the type of aquifer depressed with a clay layer as the upper and lower limits of the aquifer. The subsurface water is estimated to have a flow direction from East to West in a confined aquifer.
KAJIAN PENENTUAN LETAK SARINGAN PADA SUMUR BOR DAN DESAIN KONSTRUKSINYA DI AREA KAMPUS INSTITUT TEKNOLOGI SUMATERA (ITERA) Bilal Al Farishi; Muhamad Ragil Setiawan; Wijayanti Ashuri
KURVATEK Vol 4 No 2 (2019): November 2019
Publisher : Institut Teknologi Nasional Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33579/krvtk.v4i2.1180

Abstract

Clean water is a fundamental need for every kind of activities. ITERA as a university with various kind of learning activities cannot be separated from the need for clean water. Along with the rapid development of the campus, ITERA also requires a plan in order to provide clean water, one of which is by conducting a study of borehole construction design. This study was conducted because groundwater is one of the largest providers of clean water and must be managed properly. This study examines the shape of the construction and the right location of the filter on the borehole by looking at the geological and hydrogeological conditions and the position of the aquifer. Based on the study conducted, the geological conditions of the study area are in the Lampung Formation with the dominance of Tuff lithology. The position of the aquifer is found at a depth of 6.8 meters. Thus, the location of the filter in making bore wells should be at a depth of 20-25 meters and 40-50 meters. The filter made at these two depths is an anticipatory step if the groundwater drought during the dry season. Keywords: ITERA, clean water, aquifer, bore wells.
IDENTIFIKASI KAWASAN RAWAN LONGSOR BERDASARKAN KARAKTERISTIK BATUAN PENYUSUN DI KOTA BANDAR LAMPUNG Lea Kristi Agustina; Danni Gathot Harbowo; Bilal Al Farishi
Elipsoida : Jurnal Geodesi dan Geomatika Vol 3, No 01 (2020): Volume 03 Issue 01 Year 2020
Publisher : Department of Geodesy Engineering, Faculty of Engineering, Diponegoro University,Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (410.113 KB) | DOI: 10.14710/elipsoida.2020.7769

Abstract

Kota Bandar Lampung memiliki topografi yang cukup beragam berupa lembah maupun punggungan bukit, dalam perkembangannya banyak kawasan pemukiman yang tersebar diantara perbukitan. Bencana longsor merupakan salah satu bencana yang sering terjadi di Indonesia. Perlu adanya kajian daerah rawan longsor beserta mitigasi bencana secara spesifik yang menjadi langkah konkrit dalam mengurangi angka korban jiwa maupun materi. Banyak faktor yang mempengaruhi rawan bencana longsor, yaitu: tingkat kemiringan dari kelerengan, tutupan lahan, jenis batuan dan tanah, serta didukung dengan data kejadian sebelumnya. Gambaran permukaan bumi khususnya daerah rawan longsor dapat direpresentasikan dalam peta, diawali dengan disusunnya dataset fundamental berdasarkan parameter yang berpengaruh kejadian longsor. Setiap parameter yang mempengaruhi kejadian longsor yang digunakan memiliki besar bobot yang berbeda dan terangkum dalam metode tumpang susun (Overlay). Meninjau area rawan di Kota Bandar Lampung terdapat sisa endapan gunungapi menghasilkan geomorfologi bukit terjal dimana penyusun batuannya adalah tuff dan breksi, yang kini bisa diamati di Kota Bandar Lampung, diantaranya adalah Bukit Sulah Sukarame, Bukit Koga Kedaton, Bukit Kaliawi dan Bukit Randu Tanjungkarang. Selain itu, terdapatnya banyak sesar yang berarah NW-SW sejajar orientasi Teluk Lampung, beberapa bukit di sekitarnya memiliki morfologi dengan curam. Batuan penyusunnya pun memiliki banyak rekahan, sehingga cenderung menjadikan lereng menjadi tidak stabil. Inilah yang membuat beberapa daerah di Kota Bandar Lampung rawan terjadi longsor.
PETROLOGI GRANITOID KAPUR DI KOMPLEKS GRANITOID PADEAN Yogi Adi Prasetya; Lamganda Nainggolan; Bilal Al Farishi
JGE (Jurnal Geofisika Eksplorasi) Vol 8, No 2 (2022)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v8i2.201

Abstract

Batuan granitoid di Provinsi Lampung dapat ditemukan di peta geologi regional lembar Kota Agung dan Lembar Tanjungkarang. Masih sedikitnya penelitian tentang batuan granitoid Formasi Granit Kapur di Lampung mendasari penelitian ini. Tujuan penelitian adalah untuk mengidentifikasi jenis batuan granitoid dan melihat komposisi mineral batuan granitoid Formasi Granit Kapur. Metode yang digunakan adalah observasi lapangan untuk deskripsi petrologi dan pengambilan sampel batuan dan dengan metode pengamatan petrografi. Dari hasil observasi lapangan didapatkan 3 jenis batuan granitoid di lokasi penelitian dengan warna, komposisi mineral dan ukuran kristal yang berbeda, 3 batuan tersebut adalah Tonalit, Granodiorit dan Monzogranit, komposisi mineral utama dari batuan granitoid di lokasi penelitian antara lain, plagioklas, potassium feldspar, kuarsa, hornblende dan biotit, dengan komposisi mineral sekunder antara lain klorit, apatit, muskovit, titanit, turmalin dan opak. Dari hasil penelitian dapat diinterpretasikan jika batuan granitoid di lokasi penelitian berasal dari satu magma yang sama dan hasil proses diferensiasi magma dimana tonalit membeku terlebih dulu dan monzogranit yang memiliki ukuran kristal paling besar dan diinterpretasikan merupakan hasil kristalisasi di tahap akhir dari pembekuan magma. Dari data kelimpahan mineral dapat diklasifikasikan jika batuan granitoid di daerah penelitian merupakan tipe KCG (K-rich and K-feldspar porphyritic Calc-alkaline Granitoids).
Basaltic Lava Characteristic in Goa Pandan Area, Sukadana, East Lampung: Inferences from Stratigraphy and Petrography Analysis Happy Christin Natalia Sirait; Bilal Al Farishi; Nono Agus Santoso; Andreas Maruli Pakpahan; Hissy Ijitiha Sari; Angga Jati Widiyatama; Risky Martin Antosia
Journal of Geoscience, Engineering, Environment, and Technology Vol. 8 No. 2 (2023): JGEET Vol 08 No 02 : June (2023)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25299/jgeet.2023.8.2.12118

Abstract

The presence of extensive basalt formations in East Lampung has its own attractions in the field of geology, particularly the presence of Goa Pandan as a lava cave and tourist attraction in East Lampung. The presence of basalt lava in the southern part of the South Sumatra Basin has drawn attention to the presence of this lava, but detailed research on the characteristics of the lava and its formation process is still very rare. This study aims to determine the eruption period of the basalt lava and magma evolution process based on the correlation between lava stratigraphy and petrography analysis. Field observations show a lava sequence that forms Goa Pandan. Each lava sequence is characterized by autobreccia and vesicular structures on the surface. In addition, the presence of columnar joints, sheeting joints, massive lava, and other additional structures indicate the characteristics of low-viscosity basalt lava. The presence of mineral structures and abundance under the microscope clearly shows the magma formation process when basalt lava flowed on the surface. Resorption-overgrowth of plagioclase and pyroxene minerals indicates an open system when basalt lava flowed on the surface. In addition, the presence of zoning and patching in plagioclase minerals indicates that magma variability is influenced by temperature. The documentation of this lava stratigraphy can serve as a basis for further understanding of magma characteristics and formation processes. There is still much geological work that can be done in the research area to get a detailed picture of the evolution process of magma and the presence of basalt lava in this area.
Studi Awal Kualitas Cekungan Air Tanah (CAT) Bandar Lampung dalam Pemenuhan Kebutuhan Air untuk Masyarakat Selma Nurul Fauziah; Bilal Al Farishi; Luhut Pardamean Siringoringo
Journal of Science, Technology, and Visual Culture Vol 2 No 2 (2022): Juli 2022
Publisher : Jurusan Teknologi Produksi dan Industri, Institut Teknologi Sumatera

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Bandar Lampung merupakan salah satu kota besar di Indonesia. Kebutuhan air bersih Bandar Lampung meningkat seiring dengan bertambahnya jumlah penduduk dan kegiatan industri. Suplai air yang dilakukan oleh PDAM Way Rilau hanya dapat melayani 32% dari total penduduk Bandar Lampung. Hal ini mengindikasikan bahwa sebagian besar penduduk Bandar Lampung mengambil air tanah untuk memenuhi kebutuhan air sehari-hari. Penelitian ini dilakukan untuk mengetahui kondisi air tanah di CAT Bandar Lampung, baik kuantitas maupun kualitas. Jumlah sampel yang digunakan yaitu sebanyak 15 sampel. Berdasarkan hasil analisis kimia air tanah yang diplotkan dalam diagram piper, diketahui bahwa fasies hidrogeokimia pada daerah penelitian terdiri dari dua jenis yaitu berjenis natrium bikarbonat dan magnesium bikarbonat. Tipe air bikarbonat mengindikasikan air tanah berasal dari air tanah yang dangkal. Sedangkan kation berupa magnesium dan natrium mengindikasikan air tanah tersebut mengalir melalui jenis batuan yang berbeda. Kandungan nitrat hasil analisis memiliki nilai maksimal sebesar 0,85 mg/L, sedangkan nilai minimal sebesar 0,24 mg/L, dan nilai rata-rata sebesar 0,6 mg/L. Berdasarkan nilai kandungan nitrat tersebut, air tanah pada sample yang diambil berada di bawah nilai baku mutu mengacu pada Permenkes No. 492/MENKES/PER/IV/2010 sebesar 50 mg/L.
Slope Stability Analysis Throughout Road Around Bukit Barisan Selatan National Park (BBSNP) using Fellenius Method Radityo, Daniel; Bilal Al Farishi; Rezky Naufan Hendrawan; Alviyanda; Imam Ahmad Sadisun
Journal of Geoscience, Engineering, Environment, and Technology Vol. 9 No. 3 (2024): JGEET Vol 09 No 03 : September (2024)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25299/jgeet.2024.9.3.14902

Abstract

Bukit Barisan Selatan National Park (BBSNP) is a nature conservation area in Indonesia. The slope stability of the interprovincial roads in BBSNP needs to be assessed for slope stability. This study assesses slope stability using the Fellenius method for the factor of safety calculation. The data utilized consists of geological and structure regional conditions, soil descriptions, soil physical and mechanical properties, water content, liquid limit, plastic limit, plasticity index, specific gravity, soil strength, slope dimensions, and slope weight. The sampling process is conducted un-disturb, followed by laboratory testing. The laboratory tests conducted include soil elasticity and plasticity, soil cohesion, and internal friction angle. The critical slopes at LT-L01 and LT-L23 are compromised due to the low cohesion values, making both slopes susceptible to landslides. The stable slope at LT-R04, LT-L15, LT-L19, and LT-R30 exhibit variability properties across the slopes. The lithology for slope LT-R04 consists of inorganic clay with high plasticity, slopes LT-L15 and LT-R30 have same lithology of silty clay with medium plasticity, while slope LT-L19 has lithology of silty clay with low plasticity. The safety factor values indicate stability due to moderate - high cohesion, contributing to slope stability. Material compaction is required to enhance cohesion values on the slopes. Additionally, need to mitigate water saturation conditions in the slope materials.
Analysis of Subsidence Hazards in Pandan Cave Area, Giri Mulyo Village, Marga Sekampung District, East Lampung using Analytical Hierarchy Process Bilal Al Farishi; Natalia, Happy Christin; Naufal, Rifqi Andi; Aganda, Riyanto Dedinta; Octafiani, Aulia; Hita Kirana; Depri; Pakpahan, Andreas Maruli; Sari, Hissy Ijitiha; Santoso, Nono Agus; Antosia, Risky Martin; Putri, Intan Andriani
Journal of Geoscience, Engineering, Environment, and Technology Vol. 9 No. 2 (2024): JGEET Vol 09 No 02 : June (2024)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25299/jgeet.2024.9.2.16848

Abstract

Pandan Cave is a basalt lava cave which is a unique geological tourism area located in Giri Mulyo Village, Marga Sekampung District, East Lampung Regency, Lampung Province. This cave was formed when the lava flow cooled at the top because it was in contact with the cold atmosphere, while at the bottom it was still flowing. This uniqueness caused Pandan Cave to become one of the tourist attractions that was once crowded with tourists. However, the condition of this cave is still very natural which can lead to the risk of geological disasters such as subsidence which can endanger tourists, so it is necessary to research to minimize the occurrence of geological disasters in the area. This research was conducted by observing aerial photographs, collecting data directly in the field, and then processing it with the Analytical Hierarchy Process (AHP). Parameters used in this AHP method include lithology, vegetation, weathering, rock mass class, and cave roof thickness. The existence of subsidence in the study area is influenced by weathering (34%), vegetation (31%), thickness of the cave roof layer (16%), lithology (10%), and rock mass class (9%). Based on the overlay results for each parameter that has been weighted, the Pandan Cave tourism area is divided into three subsidence hazard zone classifications, that is low hazard zone with value of 0.28-0.44, medium hazard zone with range of 0.44-0.60, and high hazard zone with range of 0.60-0.75. Through the Analytical Hierarchy Process (AHP) method and overlay of each parameter used, the distribution of subsidence hazard zones in the study area was obtained.  The low threat zone of 27.57 ha is about 57.07% of the total research area, the medium threat zone is 15.86 ha or about 32.83% of the total research area, and the high threat zone is 4.88 ha or about 10. 10% of the total research area.