PEMODELAN 2D DATA GROUND PENETRATING RADAR (GPR) PADA LAHAN GAMBUT DI DESA JATI MULYO

Research has been conducted using the ground penetrating radar (GPR) method which aims to determine subsurface lithology on peatlands in Jati Mulyo Village based on 2D modeling. The GPR method is one of the geophysical methods that applies electromagnetic wave propagation. GPR data measurements were carried out as many as 3 passes with each length of 200 meters. The result of the GPR measurement is a 2D model that describes subsurface lithology. The response of this 2D model is in the form of a distribution of color variations starting from yellow-red, green, light blue -dark blue. The yellow-orange color response indicates the presence of minerals found on peatlands. The green response describes the soil below the surface. While the blue response indicates a cavity filled with water. This is appropriate based on the geology of this peatland is a sedimentary deposit that has pores filled with water and the presence of mineral content contained in the peat soil.  

PENYELIDIKAN AKUIFER BERDASARKAN NILAI RESISTIVITAS DI KAWASAN GAMBUT MENGGUNAKAN METODE GEOLISTRIK KONFIGURASI SCHLUMBERGER DESA JATI MULYO

Telah dilakukan penelitian dengan menggunakan metode geolistrik konfigurasi Schlumberger yang bertujuan untuk mengetahui keberadaan akuifer baik dari segi kedalaman maupun ketebalan akuifer di Desa Jati Mulyo Kecamatan Dendang Kabupaten Tanjung Jabung Timur, Provinsi Jambi. Pengukuran di lapangan sebanyak 15 titik sounding dengan masing-masing panjang lintasan 400 m, diperoleh jenis batuan dan nilai resistivitas dari hasil pengolahan melalui software IPI2Win sebagai berikut, yaitu top soil dengan nilai resistivitas 20 Ωm sampai 200 Ωm, lempung dengan nilai resistivitas berkisar antara 1 Ωm sampai 15 Ωm, kemudian lempung pasiran yang memiliki nilai resistivitas berkisar antara 15 Ωm sampai 29 Ωm, selanjutnya untuk pasir dengan nilai resistivitas berkisar antara 29 Ωm sampai 100 Ωm, dan kerikil dengan nilai resistivitas besar dari 100 Ωm. Lapisan pasir dan kerikil disini diduga sebagai lapisan yang membawa air (akuifer) secara baik, dikarenakan memiliki nilai porositas dan permeabilitas yang cukup tinggi. Berdasarkan hasil pemodelan 2D yang telah diolah menggunakan software RockWork 15, lapisan yang berpotensi sebagai akuifer berada pada kedalaman 20 m sampai 50 m. Dimana pola akuifer semakin mendalam dan menebal kearah timur laut. Selain itu akuifer juga berada pada kedalaman 75 m sampai 100 m di Barat Daya pemukiman Desa Jati Mulyo. Sehingga untuk ketebalan akuifer di Desa Jati Mulyo berkisar antara 25 m sampai 30 m. Kata kunci : Akuifer; Resistivitas; Schlumberge

Identifikasi Batuan Granit Daerah Prospek Panas Bumi Nyelanding menggunakan Metode Magnetik

This study aimed to identify granite rocks around the Nyelanding geothermal area, especially in the geothermal manifestations. This research used the magnetic method to analyze the subsurface structure of the geothermal area. Correction of magnetic data was performed in Microsoft excel 2010 software and two-dimensional modeling was performed using Oasis Montaj 8.4. The results showed that there are three layers of rock under Nyelanding hot springs, namely granite with a susceptibility of 0.009 - 0.05 SI to a depth of 500 meters and a layer of sandstone - clay, as well as layers of clay, gravel and silt with a susceptibility of 0.00001 - 0, 00005 SI. In conclusion, the local geology of the Nyelanding hot spring area is dominated by the presence of granite to a depth of 500 meters. The results of forward modeling on layers A-A' and C-C' show the subsurface structure of Nyelanding hot springs in the form of a granite rock basin which is estimated to be able to accumulate geothermal energy. Key words: Nonvolcanic Geothermal, Magnetic Method, Granite Susceptibility, Forward Modelin

Penentuan Zonasi Bencana Tsunami di Kabupaten dan Kota Pesisir Provinsi Sumatera Barat

Abstract: The purpose of this study was to determine how the tsunami disaster zoning in the Regency and Coastal City of West Sumatra Province was determined. The survey results show that geographically the regencies and cities on the coast of West Sumatra are around the threat of a tsunami, in addition to economic activities, government activities, and high population density around the coastal area. Regencies and cities located on the coast of West Sumatra, including West Pasaman Regency, Agam Regency, Padang Pariaman Regency, Pariaman City, Padang City, Pesisir Selatan Regency, and the Mentawai Islands, are feared to be the following places to be hit by a tsunami, for this reason, efforts are needed - efforts to overcome the tsunami hazard. In conclusion, the tsunami risk zone in the province of West Sumatra, which is very dangerous, is in the Mentawai archipelago with a wave height of 20-35 m and a wave arrival time of 10-20 minutes with a warning level of alert. And the story of tsunami disaster risk in coastal districts and cities of West Sumatra province is divided into four zones, namely: Not dangerous, Less dangerous, namely West Pasaman district, the danger is Agam district, Pariaman city, Padang Pariaman district, Padang city, and Pesisir Selatan district, Very dangerous namely the Mentawai Islands.   Keywords: ArcGis 10.3, Comcot, Tsunam

APLIKASI GEOLISTRIK KONFIGURASI WENNER DALAM MENDETEKSI PENCEMARAN AIR TANAH AKIBAT GAMBUT PADA DESA SUNGAI TERAP

Sungai Terap Village, Betara District, Tanjung Jabung Timur Regency is one of the areas in Jambi Province which is composed of peat soil. Peat land in this village is used by the community as agricultural and plantation land. As a result, the peat soil is degraded and damaged, causing groundwater pollution. The application of the resistivity geoelectric method can answer the question of groundwater pollution. In the current method that is injected into the earth and measures the potential difference on the surface. Geoelectric measurements were carried out in 4 lines with a length of 200 meters, electrode separation of 10 meters and n = 4. From the measurement results, it was found that groundwater was polluted due to peat soil because it had a very small resistivity value, namely 0.625-2.064  Ωm. This is because the chemical content contained in the peat soil will be carried away by rainwater that enters the surface. The effect of sea water intrusion can also pollute groundwater through drainage channels built on the peatlands. &nbsp

Identification of Peat Land Pollution in Sungai Terap Village Using Wenner Configuration Geoelectric Method

Dewi IK, MZ Nasri, Resta IL, Juventa J.2020. Identification of Peat Land Pollution in Sungai Terap Village Using Wenner Configuration Geoelectric Method. In: Herlinda S et al. (Eds.), Prosiding Seminar Nasional Lahan Suboptimal ke-8 Tahun 2020, Palembang  20 Oktober 2020. pp. xxx.  Palembang: Penerbit & Percetakan Universitas Sriwijaya (UNSRI). Groundwater pollution arising from the conversion of functions on peatlands in Sungai Terap Village. To identify the ground air pollution, the geoelectric method of research using Wenner was carried out. This research was conducted in 4 tracks with a length of 200 meters and the distance between the electrodes was 10 meters with 4 times the electrode spacing. The results of this study are 2D subsurface models in the form of apparent resistivity from the inversion results. The resistivity value generated in the 2D model ranges from 0.381-19 Ωm. The water content at the research location with a very small resistance value between 0.4-1.25 Ωm. The presence of groundwater is estimated to be trapped in the alluvium layer at a depth of 7.75-19.4 meters. The groundwater is thought to have been polluted because it has a resistivity value <10 Ωm. Almost every measurement path is found in polluted air due to rainfall and sea water intrusion

ANALISIS MIGRASI SEISMIK LAUT 2D METODEKIRCHHOFF PRE-STACK TIME MIGRATION DANPOST-STACK TIME MIGRATION PADA WILAYAH LAUT SERAM

Metode seismik menjadi bagian dalam metode pemetaan struktur bawah laut dengan teknologi akustik. Metode ini memanfaatkan perambatan, pemantulan, dan pembiasan gelombang suara. Geologi Papua dipengaruhi dua elemen tektonik besar yang saling bertumbukan dan serentak aktif, sehingga wilayah Laut Seram menjadi menarik untuk dipelajari baik dalam ekplorasi hidrokarbon maupun proses tektoniknya. Migrasi adalah tahapan dalam pengolahan seismik yang bertujuan untuk mengembalikan reflektor miring ke posisi waktu pantul awalnya dan untuk menghilangkan efek difraksi yang muncul akibat adanya struktur-struktur tertentu. Metode Kirchhoff dapat menyelesaikan masalah kompleks dalam seismic section, dan dapat mengatasi dip reflektor akurat hingga batas 90˚.Lokasi data penelitian ini terletak di Laut Seram Papua Barat 131°15’ BT - 132°45’ BT dan 3°0’ LS - 4°30’ LS. Tahapan pada penelitian ini meliputi pre-processing meliputi penerapan geometri, editing, filtering, dekonvolusi dan F-K Filter. Tahapan Processing meliputi analisis kecepatan, SRME, Stacking dan migrasi Kirchhoff. Pada tahapan akhir penelitian membandingkan dan menganalisa hasil migrasi dari variasi nilai aperture migrasi, perbandingan migrasi pre-stack dan post-stack pada migrasi domain waktu serta menentukan struktur geologi yang tercitra pada daerah penelitian.Pada penelitian ini nilai aperture 2400 m memberikan hasil yang paling baik. Metode SRME memberikan hasil yang signifikan dalam menghilangkan efek multiple daripada metode dekonvolusi prediktif dan F-K Filter. Hasil migrasi pre-stack tercitra lebih baik daripada post-stack terutama pada reflektor miring dan kompleks. Struktur geologi yang tercitra pada Laut Seram meliputi batuan dasar, didominasi oleh struktur sesar naik akibat kompresi dari struktur busur Banda akibat tumbukan antar lempeng dan beberapa ksekuen pengendapan pada Palung Seram

RELOKASI HIPOSENTER GEMPABUMI DENGAN MENGGUNAKAN METODE DOUBLE DIFFERENCE SERTA IMPLIKASINYA TERHADAP SEISMOTEKTONIK DI WILAYAH SUMATERA BARAT

West Sumatra is one of the regions with a high level of seismicity due to a very active tectonic order. The tectonic system, namely; Subduction zone between the Indian-Australian tectonic plate and the Eurasian plate, Mentawai Fault System (MFS) and Sumatra Fault System (SFS). The accuracy of the location of the earthquake is needed to determine the absolute location of the hypocenter, the method used is the double difference method. The double difference method identifies adjacent earthquake pairs by making travel time corrections at stations. The results of the earthquake hypocenter relocation with the double difference method can obtain a more accurate hypocenter location where, the residual travel time after relocation gets smaller to near zero indicating a better residual value of the relocation results compared to the residual value before being relocated. So, the earthquake parameters obtained are better than before being relocated.Keywords : West Sumatra, Earthquakes, Hypocenter Relocation, Double Difference Metho

SISTEM INFORMASI AKADEMIK PADA SMK YAYASAN PEMBANGUNAN PENDIDIKAN BEKASI

ABSTRACT— Advances in technology today is mainly based on the Internet is very helpful in providing information quickly and easily. Many found from schools that do not use the internet to provide information about the school such as new student enrollment, academic value information, and activities that exist in school. SMK YPP (Yayasan Pembangunan Pendidikan) Bekasi is one of the schools that do not have a system of information via the internet and feels is in need of a web-based information system in order to provide better convenience for teachers, students, and the community. In designing a web based academic system used waterfall method, the use of this information system provides easy access to information, values, and activities that will take place, besides the author using the program tools UML (Unified Modeling Language) for smooth understanding. Keywords: Information Systems, waterfall, UML. Intisari— Kemajuan teknologi saat ini terutama berbasis internet sangat membantu dalam memberikan informasi secara cepat dan mudah. Banyak ditemukan dari sekolah-sekolah yang belum memanfaatkan internet untuk memberikan informasi mengenai sekolah seperti pendaftaran siswa baru, informasi nilai akademik, dan kegiatan-kegiatan yang ada disekolah. SMK YPP (Yayasan Pembangunan Pendidikan) Bekasi adalah salah satu sekolah yang belum memiliki sistem informasi melalui internet dan dirasa sangat memerlukan sistem informasi berbasis web guna memberikan kemudahan baik untuk pengajar, siswanya, maupun masyarakat. Dalam merancang suatu sistem akademik berbasis web ini digunakan metode waterfall, penggunaan sistem informasi ini memberikan kemudahan dalam mengakses informasi, nilai, dan kegiatan yang akan berlangsung, selain itu penulis menggunakan tools program UML (Unified Modelling Language) demi kelancaran pemahaman.ABSTRACT— Advances in technology today is mainly based on the Internet is very helpful in providing information quickly and easily. Many found from schools that do not use the internet to provide information about the school such as new student enrollment, academic value information, and activities that exist in school. SMK YPP (Yayasan Pembangunan Pendidikan) Bekasi is one of the schools that do not have a system of information via the internet and feels is in need of a web-based information system in order to provide better convenience for teachers, students, and the community. In designing a web based academic system used waterfall method, the use of this information system provides easy access to information, values, and activities that will take place, besides the author using the program tools UML (Unified Modeling Language) for smooth understanding. Keywords: Information Systems, waterfall, UML