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Topography changes and thermal distribution at the Kelud crater after the 2014 Plinian eruption Wahyudi Wahyudi; Ari Setiawan; Heriansyah Putra; Herlan Darmawan; Imam Suyanto; Irwan Meilano; Irzaman irzaman; Maria Evita; Mitra Djamal; Moh Yasin; Nina Siti Aminah; Perdinan Perdinan; Retna Apsari; Wahyu Srigutomo; Wiwit Suryanto
Indonesian Journal of Geography Vol 52, No 3 (2020): Indonesian Journal of Geography
Publisher : Faculty of Geography, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijg.51986

Abstract

Topography of a volcano crater can change due to endogenic processes such as deformation or eruption, or surface processes. Erosion and deposition are surface processes that may occur and gradually change the slope of the inner volcano crater. Here, we investigated erosion and deposition processes that occurred in the Kelud crater after the 2014 plinian eruption. We used high-resolution Digital Elevation Models (DEMs) and orthomosaic images derived by drone photogrammetry that acquired between September 2018 and July 2019. We obtained hundreds of aerial images which were reconstructed to obtain 3D models of Kelud’s crater by using Structure from Motion (SfM) technique. Results show erosions at alluvial fans that dominantly located at the east valleys of Kelud crater. The erosion removed the volcanic materials up to -5 m which transported and deposited close to the vicinity of the Kelud crater. The deposition process causes the increase of the Kelud crater lake up to 3 m. Moreover, we also mapped the thermal distribution of the Kelud crater lake by using low cost thermal camera. Our thermal investigation is able to identify some hotspots at the vicinity of the Kelud crater lake with range temperature of 43.7°C – 55.3°C, while the average apparent temperature of the Kelud crater lake is ~ 29°C. This high temperature area may indicate underwater active fractures that continuously release volcanic gasses which leads to convection heat transfer through Kelud’s water lake.
Perbandingan Survei dan Analisis Data Geolistrik Sounding Daerah Pantai dan Pegunungan Studi Kasus Penyelidikan Air Tanah di Kabupaten Kendal, Jawa Tengah Imam Suyanto
INDONESIAN JOURNAL OF APPLIED PHYSICS Vol 3, No 02 (2013): IJAP VOLUME 03 ISSUE 02 YEAR 2013
Publisher : Department of Physics, Sebelas Maret University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/ijap.v3i02.1242

Abstract

A geoelectrical method research have been done to find out the presence of aquifer at mountain and coastal area in Kabupaten Kendal, Central java, February 2008 using VES (Vertical Electrical Sounding) method, Schlumberger configuration. 22 measurement location spread out at coastal and mountain area with the 500 meter long each measurement point. Each measurement point presented in resistivity curve and the thick of each detected subsurface layer asa result of Progress III data processing software. From the result of this measurement shown that the aquifer at coastal area defined as confined a aquifer with the range of thickness more than 50 meter thick and the range of resistivity value between 5 – 15 Ohm meter and the eksistence of the detected subsurface layer shown mostly at each sounding point. For the mountainarea, the the deep of the aquifer around hundred meters at the subsurface with the range ofthickness about 10-20 meters with the range of resistivity value 10-80 Ohm meter.
TOMOGRAFI GEOLISTRIK UNTUK IDENTIFIKASI LITOLOGI PADA LOKASI RENCANA BENDUNG DAN TEROWONGAN DI SULAWESI UTARA Boko Nurdiyanto; Imam Suyanto; Bambang Sunardi; Pupung Susilanto
Jurnal Meteorologi dan Geofisika Vol 17, No 1 (2016)
Publisher : Pusat Penelitian dan Pengembangan BMKG

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (5160.423 KB) | DOI: 10.31172/jmg.v17i1.373

Abstract

Pengukuran geolistrik telah dilakukan untuk mengidentifikasi litologi dan akuifer berdasarkan resistivitas batuan pada lokasi rencana pembangunan bendung dan terowongan di daerah Sulawesi Utara. Survei tiga lintasan menggunakan konfigurasi dipole-dipole dengan 32 elektroda (a = 5,5 m) dan kabel ekstensi 9 elektroda (a = 20 m). Analisa tomografi resistivitas menunjukan daerah survei tersusun oleh tanah berupa lempung pasiran (resistivitas rendah di permukaaan), breksi Tondano (30 –1000 Ωm), lapukan tufa Tondano (30 – 80 Ωm) dan tufa Tondano (< 30 Ωm). Di area bendung pada bagian tepi sungai terdapat tanahtipis, breksi Tondano danlapisan tufa Tondano. Lapisan Tondano daerah terowongan telah mengalami pelapukan menjadi lempung pasiran dengan ketebalan hingga 15 m, sedangkan lapisan dibawahnya berupa breksi tondano yang telah lapuk menjadi pasir kelempungan dengan fragmen kerikil (40 – 125 Ωm) hingga bongkah (200 – 2000 Ωm) dengan ketebalan 10 – 35 meter. Pada kedalaman 50 m ditemukan intrusi andesit, kekar-kekar pada andesit diisi oleh air. Terdapat setidaknya ada lima akuifer dengan kedalaman sekitar 50 meter diantara lokasi rencana surgetank sampai powerhouse. Geoelectric measurements have been conducted to identify the lithology and aquifers based on rock resistivity at a dam and tunnel site plan in North Celebes using three-lines survey with 32 electrodes (a= 5,5 m) dipole-dipole configuration and 9 electrode extension cables (a=20 m). Based on electrical resistivity tomography (ERT), it can be interpreted that the survey area is composed of soil in the form of sandy clay (low resistivity), breccia Tondano (30-1000 Ωm), weathered of Tondano tuff (30-80 Ωm) and tondano tuff(<30 Ωm). In the area of the dam, there are thin soil, a layer of tuff and breccia tondano on the river banks. Tondano layer in the tunnel area has experienced weathering into sandy clay with a thickness of up to 15 m, while layers below it has took the form of breccia, which has weathered into sandy loam with fragments of gravel (40-125 Ωm) to boulder (200-2000 Ωm) with a thickness of 10 - 35 meters. Andesite intrusion was found at a depth of 50 m, with cracks on andesite filled by water. There are at least five of the aquifers at a depth of about 50 meters between the location of surgetank to the powerhouse plan.
Analisis Data Resistivitas Dipole-dipole Untuk Identifikasi Dan Perhitungan Sumber Daya Asbuton Di Daerah Kabungka, Pasarwajo, Pulau Buton, Sulawesi Tenggara (Halaman 1 s.d. 7) Imam Suyanto; Agung Setyo Utomo
Jurnal Fisika Indonesia Vol 17, No 50 (2013)
Publisher : Department of Physics Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (639.672 KB) | DOI: 10.22146/jfi.24414

Abstract

Telah dilakukan penelitian sebaran batuan aspal buton (asbuton) dengan menggunakan metode resistivitas dipole-dipole. Penelitian ini bertujuan untuk memetakan sebaran asbuton secara 2-D maupun 3-D seta menghitung cadangan asbuton daerah penelitian. Penentuan sebaran asbuton didasarkan pada perbedaan nilai resistivitas asbuton dengan batuan di sekitarnya. Pengolahan dan pemodelan data resistivitas menggunakan software Res2Dinv, sehingga didapatkan model penampang resistivitas asbuton. Penentuan nilai asbuton daerah penelitian didasarkan pada lintasan yang melewati singkapan asbuton, yaitu antara 90 – 600 Ωm. Sebaran asbuton setelah dilakukan pemodelan secara 2-D maupun 3-D banyak terdapat pada Formasi Tondo dengan bentuk asbuton berupa bolder dengan ketebalan bervariasi antara 1 – 40 meter. Besar potensi cadangan asbuton dimasukkan dalam 2 kategori yaitu : cadangan terukur dan cadangan tereka. Besar potensi asbuton pada cadangan terukur dengan volume 6,1 juta meter kubik (m3) adalah 17,0 juta ton. Besar potensi asbuton cadangan tereka dengan volume 22,2 juta meter kubik (m3) adalah 62,1 juta ton.
Rancang Bangun Sistem Akuisisi Data Infra Merah Menggunakan Pesawat Udara Tanpa Awak (UAV) untuk Memantau Aktivitas Gunungapi wahyudi wahyudi; Kirbani Sri Brotopuspito; Imam Suyanto
Jurnal Fisika Indonesia Vol 23, No 1 (2019)
Publisher : Department of Physics Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jfi.v23i1.39975

Abstract

 Sebuah rancang bangun instrumen untuk sistem akuisisi data termal yang digunakan untuk pemantauan aktivitas gunungapi dengan meman-faatkan pesawat udara tanpa awak (UAV) telah dilakukan. Pesawat udara tanpa awak dipilih karena kemampuannya dalam menjangkau tubuh gunung dengan lebih mudah dan aman. Sensor infra merah digunakan sebagai muatan agar mampu mengukur suhu kawah dan permukaan gunungapi tanpa ada kontak langsung.       Sistem yang dibangun terdiri dari 3 perangkat utama, yakni sensor infra merah tipe Flir One Pro yang berfungsi sebagai kamera termal dan kamera visual, hand phone yang dilengkapi dengan software Redmi Note 5 yang berfungsi sebagai alat perekam data dan IMU (Inertial Measurement Unit), serta UAV (Unmanned Aerial Vehicle) yang berfungsi sebagai pesawat udara tanpa awak yang mengangkut sensor beserta alat perekam datanya.       Uji coba telah dilakukan baik di laboratorium maupun di lapangan. Uji coba pemetaan termal dilakukan di atas kawah G. Kelud pada ketinggian jelajah 100 m pada area seluas (100x300) m2 dengan laju rata-rata 15 m/s. Hasil uji coba menunjukkan bahwa sistem telah berfungsi dengan baik, meskipun terdapat kendala yang harus diperbaiki yang berkaitan dengan waktu melakukan pemetaan. Direkomendasikan agar pemetaan termal dilakukan pada malam hari sehingga obyek yang dipetakan mempunyai background termal yang relatif tetap, dan peta termal yang dihasilkan menjadi lebih konsisten.
Pemasangan Sistem Telemetri Untuk Pemantauan Aktivitas Gunungapi (Studi Kasus Pemantauan Suhu G. Kelud, Jawa Timur) Imam Suyanto; Wahyudi Wahyudi; Eddy Hartantyo
Jurnal Fisika Indonesia Vol 24, No 2 (2020)
Publisher : Department of Physics Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jfi.v24i2.53900

Abstract

Seringkali pemantauan gunungapi yang dilakukan secara langsung sangat berbahaya, terutama pada saat ada kenaikan aktivitas. Untuk itu diperlukan upaya agar pemantauan gunungapi dapat dilakukan dari jarak yang aman. Untuk maksud tersebut telah dibuat rancang bangun sistem telemetri, yang untuk langkah pertama digunakan untuk memantau perubahan suhu kawah Gunung Kelud, Kabupaten Kediri, Propinsi Jawa Timur. Sistem telemetri yang telah terpasang diharapkan dapat digunakan dalam jangka waktu lama, minimal dalam 1 tahun mendatang akan terus dievaluasi. Pemantauan bisa dilakukan 24 jam sehingga jika terjadi keadaan kritis dapat segera diketahui.Penelitian dimulai dengan merancang sistem telemetri yang praktis, berbiaya rendah, dan mudah dalam perawatannya. LoRaWAN (Long Range Wide Area Network) dipilih karena dapat mendukung tujuan tersebut. Parameter suhu dipilih untuk diamati karena tidak memerlukan pencacahan tinggi dan dapat mencerminkan adanya dinamika dari Gunung Kelud.
TOMOGRAFI GEOLISTRIK UNTUK IDENTIFIKASI LITOLOGI PADA LOKASI RENCANA BENDUNG DAN TEROWONGAN DI SULAWESI UTARA Boko Nurdiyanto; Imam Suyanto; Bambang Sunardi; Pupung Susilanto
Jurnal Meteorologi dan Geofisika Vol. 17 No. 1 (2016)
Publisher : Pusat Penelitian dan Pengembangan BMKG

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31172/jmg.v17i1.373

Abstract

Pengukuran geolistrik telah dilakukan untuk mengidentifikasi litologi dan akuifer berdasarkan resistivitas batuan pada lokasi rencana pembangunan bendung dan terowongan di daerah Sulawesi Utara. Survei tiga lintasan menggunakan konfigurasi dipole-dipole dengan 32 elektroda (a = 5,5 m) dan kabel ekstensi 9 elektroda (a = 20 m). Analisa tomografi resistivitas menunjukan daerah survei tersusun oleh tanah berupa lempung pasiran (resistivitas rendah di permukaaan), breksi Tondano (30 –1000 Ωm), lapukan tufa Tondano (30 – 80 Ωm) dan tufa Tondano (< 30 Ωm). Di area bendung pada bagian tepi sungai terdapat tanahtipis, breksi Tondano danlapisan tufa Tondano. Lapisan Tondano daerah terowongan telah mengalami pelapukan menjadi lempung pasiran dengan ketebalan hingga 15 m, sedangkan lapisan dibawahnya berupa breksi tondano yang telah lapuk menjadi pasir kelempungan dengan fragmen kerikil (40 – 125 Ωm) hingga bongkah (200 – 2000 Ωm) dengan ketebalan 10 – 35 meter. Pada kedalaman 50 m ditemukan intrusi andesit, kekar-kekar pada andesit diisi oleh air. Terdapat setidaknya ada lima akuifer dengan kedalaman sekitar 50 meter diantara lokasi rencana surgetank sampai powerhouse. Geoelectric measurements have been conducted to identify the lithology and aquifers based on rock resistivity at a dam and tunnel site plan in North Celebes using three-lines survey with 32 electrodes (a= 5,5 m) dipole-dipole configuration and 9 electrode extension cables (a=20 m). Based on electrical resistivity tomography (ERT), it can be interpreted that the survey area is composed of soil in the form of sandy clay (low resistivity), breccia Tondano (30-1000 Ωm), weathered of Tondano tuff (30-80 Ωm) and tondano tuff(<30 Ωm). In the area of the dam, there are thin soil, a layer of tuff and breccia tondano on the river banks. Tondano layer in the tunnel area has experienced weathering into sandy clay with a thickness of up to 15 m, while layers below it has took the form of breccia, which has weathered into sandy loam with fragments of gravel (40-125 Ωm) to boulder (200-2000 Ωm) with a thickness of 10 - 35 meters. Andesite intrusion was found at a depth of 50 m, with cracks on andesite filled by water. There are at least five of the aquifers at a depth of about 50 meters between the location of surgetank to the powerhouse plan.
Analisis Metode Magnetik pada Daerah Manifestasi Panas Bumi Karangrejo, Kabupaten Pacitan Mayang Bunga Puspita; Cholisina Anik Perwita; Sukir Maryanto; Imam Suyanto
INSOLOGI: Jurnal Sains dan Teknologi Vol. 2 No. 5 (2023): Oktober 2023
Publisher : Yayasan Literasi Sains Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55123/insologi.v2i5.2662

Abstract

Geothermal energy is one of the natural resources found in Pacitan Regency, alongside mining and geotourism. Geothermal manifestations in Pacitan Regency take the form of hot springs located at two points: Tinatar in the Punung District and Karangrejo in the Arjosari District. This research primarily focuses on magnetic measurement methods at the Karangrejo hot spring manifestation to provide information about its subsurface geological conditions. Data acquisition was conducted using 2 Proton Precision Magnetometers (PPM) of the Geotron G-5 brand as both base and rover instruments. The acquired data was processed with diurnal correction, IGRF correction, separation of residual-regional anomalies, and Reduce to Pole (RTP) transformation. The research results show magnetic anomaly variations in the study area ranging from -220 nT to 200 nT. Some geological structures that could potentially be associated with the Karangrejo hot spring manifestation are north-south trending faults and northeast-southwest trending faults, while the lithology of the study area is dominated by kaolin alteration and andesite rocks. It is estimated that the Karangrejo geothermal system is a fault-hosted geothermal system resulting from fault activity.
Identifikasi Akuifer Air Tanah di Desa Senawang, Kecamatan Orong Telu, Kabupaten Sumbawa Menggunakan Metode Geolistrik Schlumberger Zakaria, Muhammad Faizal; Suyanto, Imam
Jurnal Fisika Vol 10, No 1 (2020)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jf.v10i1.24519

Abstract

Senawang District is an area in Sumbawa Province with a high level of drought. This study aims to provide additional information about groundwater to support the availability of clean water in Senawang District. The study used Geoelectric-Schlumberger Method as main method of subsurface identification. The acquisition was conducted with 10 points acquisition, with spacing between points is 200 m and the line stretch of 250 m. The results of data processing are a vertical resistivity variation in depth at each point measurement. This result will be interpreted into the type of rock and the presence of groundwater. The interpretation shows that the presence of groundwater aquifer with resistivity of 12.54 – 26.28 m, thickness 4.59 – 7.95 m, depth (upper part of the layer) 23.29 – 50.56 m. The type of groundwaters aquifer in the study area are confined aquifers.
Mineralogy and Ore Characteristics of the Kujang Pb-Zn Skarn Deposit, Sukabumi Regency, West Java Suryawan, Eka Harris; Idrus, Arifudin; Suyanto, Imam; Ilmawan, Ilham; Faruqi, M.Dzulfikar
Journal of Applied Geology Vol 8, No 2 (2023)
Publisher : Geological Engineering Department Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jag.78105

Abstract

The Kujang Pb-Zn skarn deposit is known to be the newest skarn deposit found in the Sunda-Banda magmatic arc. The skarn orebodies are mostly hosted by limestone which might be the part of the Jampang Formation where dacite porphyry is interpreted to be the ore causative intrusion. Orebodies are mostly found at the contact between marbleized limestone and volcanic rocks and are controlled by NW-SE-trending strike-slip faults. Previous research on the mineralogy and ore characteristics of the Kujang Prospect remains limited on the preliminary studies. Using fieldwork data, petrography, ore microscopy, and assay data from core samples, this study is aimed to characterize the mineralogy of both alteration and ore of the deposit. The alteration of the Kujang Prospect skarn can be divided into 2 phases of alteration i.e. prograde and retrograde. The prograde alteration is characterized by the occurrence of clinopyroxene, wollastonite, and vesuvianite. Garnet is present in very rare amounts. the retrograde alteration is typified by epidote, chlorite, calcite and actinolite. Metalliferous minerals are represented by sphalerite, galena, pyrrhotite, chalcopyrite and pyrite. All ore minerals are formed at the early retrograde stage. the deposit’s average grade is 2.06% Pb, 6.45% Zn and 1.81% Cu.