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Ground Validation of GPM IMERG-F Precipitation Products with the Point Rain Gauge Records on the Extreme Rainfall Over a Mountainous Area of Sumatra Island Ravidho Ramadhan; Marzuki Marzuki; Helmi Yusnaini; Ayu Putri Ningsih; Hiroyuki Hashiguchi; Toyoshi Shimomai; Mutya Vonnisa; Syarifatul Ulfah; Wiwit Suryanto; Sholihun Sholihun
Jurnal Penelitian Pendidikan IPA Vol. 8 No. 1 (2022): January
Publisher : Postgraduate, University of Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jppipa.v8i1.1155

Abstract

Accurate satellite precipitation estimates over areas of complex topography are still challenging, while such accuracy is of importance to the adoption of satellite data for hydrological applications. This study evaluated the ability of Integrated Multi-satellitE Retrievals for GPM -Final (IMERG) V06 product to observe the extreme rainfall over a mountainous area of Sumatra Island. Fifteen years of optical rain gauge (ORG) observation at Kototabang, West Sumatra, Indonesia (100.32°E, 0.20°S, 865 m above sea level), were used as reference surface measurement. The performance of IMERG-F was evaluated using 13 extreme rain indexes formulated by the Expert Team on Climate Change Detection and Indices (ETCCDI). The IMERG-F overestimated the values of all precipitation amount-based indices (PRCPTOT, R85P, R95P, and R99P), three precipitation frequency-based indices (R1mm, R10mm, R20mm), one precipitation duration-based indices (CWD), and one precipitation intensity-based indices (RX5day). Furthermore, the IMERG-F underestimated the values of precipitation frequency-based indices (R50mm), one precipitation duration-based indices (CDD), one precipitation intensity-based indices (SDII). In terms of correlation, only five indexes have a correlation coefficient (R) > 0.5, consistent with Kling–Gupta Efficiency (KGE) value. These results confirm the need to improve the accuracy of the IMERG-F data in mountainous areas.
Analisa Receiver Function Teleseismic untuk Mendeteksi Moho pada Stasiun Bkb Data Meramex Rian Amukti; Wiwit Suryanto
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.v3i02.1272

Abstract

It has been done a research to determine internal earth using receiver function teleseismic analysis method. This method have been done by using MERAMEX (MErapi Amphibious Experiment) data from broadband seismometer BKB. Event of teleseismic is chosen from Honshu Japan with radius 30o and magnitude 7.2. This research begun by analysing radial and vertical characteristic of teleseismic eventand using bandpass filter with range 0.003 Hz – 0.5 Hz. Then Iteractive Deconvolution is used to get velocity model. The result of this model shows crustal model that has 4 Km thick upper crust, a 26 Km thick lower crust and 10 Km thick Moho transition zone, with velocity increasing gradually.
PENENTUAN KEDALAMAN KERAK BUMI DENGAN TEKNIK STACKING H-k MENGGUNAKAN MATLAB PADA DATA SINTETIK RECEIVER FUNCTION Wiwit Suryanto; Drajat Ngadmanto; Pupung Susilanto
Jurnal Meteorologi dan Geofisika Vol 11, No 1 (2010)
Publisher : Pusat Penelitian dan Pengembangan BMKG

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1258.619 KB) | DOI: 10.31172/jmg.v11i1.57

Abstract

Salah satu metode untuk mendapatkan informasi mengenai struktur di bawah permukaan bumi adalah  receiver function. Konsep dasar metode receiver function ini adalah pendekatan kedalaman kerak bumi dengan menggunakan informasi waktu tunda dari fase gelombang Ps yang merupakan konversi dari pantulan gelombang P menjadi gelombang S pada batas mantel-kerak bumi. Akurasi ditingkatkan dengan menggunakan bantuan dari waktu tiba fase-fase gelombang lain yang tiba setelahnya, yaitu fase gelombang PpPs dan PpSs+PsPs. Program diuji menggunakan dua buah model kecepatan 4 lapis dengan variasi kecepatan yang besar berada pada kedalaman masing-masing 32 km dan 38 km. Dari hasil perhitungan dengan menggunakan metode stacking H-k ini diperoleh kedalaman interface kerak sebesar 32 km dan 38 km yang bersesuaian dengan model yang dibuat. Perhitungan dengan H dan k masing-masing sebanyak 301 sample (total 301 × 301 kali perhitungan maju receiver function) diperlukan waktu selama 20 detik pada komputer dengan processor Intel Dual Core dan memori sebesar 2 GHz. One of methods to obtain information about structure beneath the earth's surface is receiver function. The basic concept of receiver function method is to estimate of the Earth's crust depth using phase delay information from Ps wave which is a conversion from P wave reflection to S wave at the earth’s crust-mantle boundary. The accuracy of the calculated depth was enhanced by using additional phases that arrived after that, i.e. PpPs and PpSs + PSPs. The program was examined using two models, each have a four-layer velocity models  with large velocity contrast at 32 km and 38 km of depth. We obtained that the depth of crust interface are about 32 km and 38 km. These depths correspond to the velocity model. It takes 20 seconds on a computer with an Intel Dual Core with memory of 2 GHz to calculate the model with 301 x 301 samples of H and k
IMPLEMENTASI PERHITUNGAN RECEIVER FUNCTION UNTUK GEMPA JAUH (TELESEISMIC) MENGGUNAKAN MATLAB Wiwit Suryanto; Boko Nurdiyanto; Suliyanti Pakpahan
Jurnal Meteorologi dan Geofisika Vol 11, No 1 (2010)
Publisher : Pusat Penelitian dan Pengembangan BMKG

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1206.63 KB) | DOI: 10.31172/jmg.v11i1.64

Abstract

Telah dilakukan pemodelan receiver function untuk data teleseismik yang direkam oleh stasiun pengamatan gempabumi 3 komponen. Perhitungan dekonvolusi dalam perhitungan receiver function ini dilakukan dalam domain frekuensi. Pemodelan dilakukan dalam sistem MATLAB. Program dapat berjalan dengan efisien, dan waktu yang diperlukan untuk perhitungan untuk model 4 lapis adalah sekitar 1,2 detik dengan menggunakan komputer Intel Atom dengan memori 1 GB. Untuk model dengan 31 lapisan, diperlukan waktu perhitungan 1,9 detik. Efektifitas program ini memungkinkan untuk dikembangkan lebih lanjut misalnya untuk keperluan inversi. Receiver function modeling for teleseismic earthquake has been implemented using MATLAB. The deconvolution process is carried out in the frequency domain for simplicity. The time required for calculating a four-layer model is about 1.2 seconds using Intel Atom 1 GB of memory. For a velocity model with 31 layers it takes 1.9 seconds using the same computer specification. The effectiveness of the program may used for other advance application especially for earth crustal inversion.
The Effect of Differences Leachate Concentration and Material Properties on Electrical Conductivity of Volcanic Deposits – Case Studies Piyungan Landfill Bantul Yogyakarta Jaingot A. Parhusip; Agung Harijoko; Doni Prakasa Eka Putra; Wiwit Suryanto
Journal of Applied Geology Vol 1, No 1 (2016)
Publisher : Geological Engineering Department Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (886.368 KB) | DOI: 10.22146/jag.26956

Abstract

Monitoring at the contaminated subsurface soil, have been conducted by using the geophysical surface method, especially for geoelectrical resistivity method. Monitoring is commonly conducted by using geoelectrical resistivity through measuring the value of Electrical Resistivity (ER) or Electrical Conductivity (EC) of leachate contaminated soil layer. EC measurement value of soil is affected by many factors, among others, particle conduction of soil materials, surface conduction, fluid conduction in the pores as well as the effect of particle shape and soil materials. Piyungan landfill is the main disposal site of Yogyakarta municipal solid waste. This landfill located mainly on the tertiary rocks of volcanic rocks and its weathering products. In order to improve the accuracy of geoelectrical measurements on resistivity in monitoring soil layers from contaminated leachate on this area, this research conducted several measurements on physical properties of soil sample and electrical properties of leachate in the saturated soil samples. The measurement of physical properties includes: porosity, clay content, particle content, and cation exchange capacity (CEC) value. The soil samples were collected from 3 locations around Piyungan Landfill. Type of soils are taken from the alluvial deposits (Sample B), weathered tuffaceous sandstone-claystone (Sample D), and weathered andesitic breccia (Sample F). Samples were made in containers, saturated with aquades-leachate solution with 12 different concentration levels. Electrical conductivity (EC) was measured by using Soil Box Miller and Geoelectric Resistivity Oyo McOhm. According to results of physical properties analysis, the grain size of soils are dominantly sandy clayey silt in grain size distribution, with clay content ranging from 33.0--38.4 %, the CEC values ranging from 26.8--52.7 meq/100 gr, and the porosity of samples B, D and F is 58.85 %, 55.30 %, 59.24 %, respectively. Based on the experiments with 12 different leachate concentrations, there is a linear increase in EC of 0.718mS/cm for every increase in electrical conductivity pore fluid (ECf ) 1 mg/l in samples B, while in samples D and F are 0.492 mS/cm and 0.284 mS/cm respectively. Plotting the data of EC vs ECf for each samples and ER vs ECf , it can be concluded the slope ofDEC/DECf differ for each samples and the electrical conductivity value of different concentration of leachate is very sensitive for alluvial deposits compare to the weathered tuffaceous sandstone-claystone and weathered volcanic breccia deposits.
Pembuatan Model Fisis Letusan Gunung Lumpur Bledug Kuwu dan Pemodelan Numerik Untuk Mengetahui Kecepatan Perambatan Gelombang Seismiknya Ahmad Fauzi Pohan; Wiwit Suryanto; Wahyudi Wahyudi
Jurnal Fisika Indonesia Vol 20, No 2 (2016)
Publisher : Department of Physics Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1755.943 KB) | DOI: 10.22146/jfi.28028

Abstract

Media fisis menggunakan akuarium berukuran 59 × 59 × 37,3 cm yang diisi material dari lumpur Bledug Kuwu. Sumber letusan dihasilkan dari tekanan kompresor yang dapat diatur kedalaman dan sudut sumbernya. Sinyal seismik direkam menggunakan geophone komponen vertikal sebanyak 3 buah dengan durasi perekaman selama 10 dan 5 detik. Data diambil dengan frekuensi sampel 2 dan 4 kHz untuk masing-masing durasi perekaman. Pemodelan numerik dilakukan menggunakan metode finite-difference orde-4 teknik convolutional perfectly matched layer (CPML) untuk mencocokkan hasil dari pemodelan fisis. Konfigurasi sumber dan geophone dibuat sesuai dengan pemodelan fisisnya. Hasil model fisis diperoleh kecepatan perambatan gelombang-P pada medium lumpur Bledug Kuwu adalah sebesar 48,74 m/s, dengan frekuensi dominan antara 20 sampai 25 Hz. Hasil perbandingan antara seismogram model fisis dan seismogram model numerik diperoleh parameter kecepatan gelombang-S sebesar 28,14 m/s, densitas lumpur sebesar 1200 Kg/m3, dan conduit dari Bledug Kuwu membentuk sudut 30° terhadap arah vertikal, dengan hasil korelasi antara model fisis dan numerik sebesar 0,9. 
Estimasi temperatur bawah permukaan reservoir Gunung Lumpur Bledug Kuwu (GLBK) Jawa Tengah menggunakan metode Geotermometri Aryono Adhi; Wahyudi Wahyudi; Wiwit Suryanto; Sismanto Sismanto; Agus Suprianto; Ellianawati Ellianawati
Jurnal Pendidikan Fisika dan Keilmuan (JPFK) Vol 5, No 1 (2019)
Publisher : UNIVERISTAS PGRI MADIUN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (345.873 KB) | DOI: 10.25273/jpfk.v5i1.3425

Abstract

Studi literatur untuk mengestimasi temperature reservoir Gunung Lumpur Bledug Kuwu telah dilakukan menggunakan metode geotermometri larutan. Perhitungan temperature diperoleh dari hasil perhitungan empiris kandungan unsure-unsur kimia terlarut pada air panas Gunung Lumpur Bledug Kuwu. Kandungan unsure ini diperoleh dari hasil analisis sampel air panas dengan metode Atomic Absorption Spectrophotometer (AAS) yang dilakukan oleh Rizqiya 2014, berupa konsentrasi Na, K, Ca, Mg dan SiO2. Dari hasil perhitungan ini, estimasi temperature reservoir Bledug Kuwu berkisar antara 90.411 – 148.354 0C.
Inverse Modeling Using Taylor Expansion Approach and Jacobi Matrix on Magnetic Data (Dyke/Magma Intrusion Cases) Agus Suprianto; Wahyudi Wahyudi; Wiwit Suryanto; Ari Setiawan; Aryono Adhi; Nurul Priyantari; Supriyadi Supriyadi; Agus Subekti
Scientific Journal of Informatics Vol 6, No 2 (2019): November 2019
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/sji.v6i2.19798

Abstract

The mathematical modelling of geological structures, i.e. magma intrusion or dyke, has been done,  based on magnetic data with inversion techniques using MatLab. The magnetic equation is a non-linear equation, and completion is done using a linear approach to non-linear mathematical models of magnetic data using the Taylor expansion approach and Jacobi Matrix. The first step of this research is to make synthetic data forward modelling from the magnetic equation of magma intrusion or dyke cases without errors, and the next stepping then add errors to the data. The next step is to do an inversion to get the parameters sought, i.e. depth and angle of the magma intrusion, by giving initial guesses, and then re-correct iteratively until convergent results are obtained. Finally, parameters of slope dyke or thin magma intrusion and its depth can be determined. The results obtained indicate that this technique can be used to get physical parameters sought from magnetic data for simple geological cases, i.e. dyke and magma intrusion.