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GRAV3D Validation using Generalized Cross-Validation (GCV) Algorithm by Lower Bounds Approach for 3D Gravity Data Inversion Adhi, Mochamad Aryono; Wahyudi, Wahyudi; Suryanto, Wiwit; Sarkowi, Muh
Scientific Journal of Informatics Vol 5, No 2 (2018): November 2018
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/sji.v5i2.16736

Abstract

The completion of gravitational data inversion results in a smooth recovered model. GRAV3D is one software that can be used to solve 3D inversion problems of gravity data. Nevertheless there are still fundamental problems related to how to ensure the validity of GRAV3D to be used in 3D inversion. One approach used is to use lower bounds as inversion parameters. In this study lower bounds are set from  to . The results obtained show that the use of lower bounds decreases resulting in a larger data misfit which means that the more data that meets the tolerance calculation, the better recovered model produced.
Inverse Modeling Using Taylor Expansion Approach and Jacobi Matrix on Magnetic Data (Dyke/Magma Intrusion Cases) Suprianto, Agus; Wahyudi, Wahyudi; Suryanto, Wiwit; Setiawan, Ari; Adhi, Aryono; Priyantari, Nurul; Supriyadi, Supriyadi; Subekti, Agus
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.
ANALISIS DAN MODEL INVERSI GAYA BERAT 2D UNTUK PENAMPAKAN SESAR PALU KORO DI SULAWESI TENGAH INDONESIA Jamidun, Jamidun; Rusydi, M.; SB, Kirbani; P, Subagio; Suryanto, Wiwit
Natural Science: Journal of Science and Technology Vol 8, No 1 (2019): Volume 8 Number 1 (April 2019)
Publisher : Univ. Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (451.862 KB)

Abstract

Analisis dan modeling mengenai struktur geologi Pulau Sulawesi khususnya wilayah Sulawesi Tengah sangat menarik sebab memiliki kompleksitas yang tinggi sebagai akibat interaksi dinamis dari tiga lempeng utama dunia. Ketiga lempeng tersebut yakni lempeng India Australia, lempeng Pasifik dan lempeng Eurasia yang dalam pergerakannya saling bertemu yang mengakibatkan daerah ini mengalami deformasi kerak bumi yang aktif. Salah satu bentuk deformasi dari gerakan dinamik adalah terbentuknya sesar Palu Koro. Metoda yang digunakan untuk mengkaji sesar tersebut digunakan metoda gayaberat. Hasil yang diperoleh menunjukkan bahwa sesar Palu Koro merupakan sesar geser mengiri dan normal. Model patahan bawah permukaan sesuai dengan penampakan morfologi topografi daerah penelitian. Bagian struktur bawah permukaan telah mengalami deformasi yang kuat dimana semua model strukturnya berbentuk struktur sekunder tidak ditemukan lagi struktur primer. Didapatkan pula batuan intrusi berkisar dari dua sampai tiga intrusi yang terlihat pada sayatan AA?. Formasi batuannya berjumlah enam jenis, yaitu batuan aluvium, formasi pakuli, formasi latimojong, kompleks wana, kompleks gumbasa dan batuan intrusi.
Microtremor Data to Strengthen the Students’ Mastery of Materials in the Implementation of Integrated Physics Learning Ningrum, Rohima Wahyu; Fauzi, Hendra; Suryanto, Wiwit; Mei, Estuning Tyas Wulan; Amelia, Risky Nuri
Jurnal Penelitian Fisika dan Aplikasinya (JPFA) Vol 10, No 1 (2020)
Publisher : Universitas Negeri Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26740/jpfa.v10n1.p81-89

Abstract

A geophysical research has been conducted to determine the level of hazard vulnerability in West Halmahera by using microtremor data. Microtremor data are analyzed using the Horizontal to Vertical Spectral Ratio (HVSR) method and it is processed using Geopsy software to know hazard vulnerability level in the region . Data analysis and processing are used as sources of information in physics learning materials using an integrated learning model. Research objectives are to train the students to understand the materials in the fields of study and to enhance other discovery ideas.This research method uses the correlational method and the type of research is experimental research. The research design is an uniquecase research design and the instrument used is tests and questionnaires. The results of this research indicate that the microtremor data using integrated learning models of integrated types have effect on the students’ Mastery of materials in the implementation of physics learning. The effect of the integrated learning model of integrated type on the students’ Mastery of materials on the concepts of vibration and waves is 16% and it is in low category. Whereas, the students' responses to integrated learning model of integrated type are quite fun and it can help to improve their mastery of the material on the concepts of vibration and waves.
GRAV3D Validation using Generalized Cross-Validation (GCV) Algorithm by Lower Bounds Approach for 3D Gravity Data Inversion Adhi, Mochamad Aryono; Wahyudi, Wahyudi; Suryanto, Wiwit; Sarkowi, Muh
Scientific Journal of Informatics Vol 5, No 2 (2018): November 2018
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/sji.v5i2.16736

Abstract

The completion of gravitational data inversion results in a smooth recovered model. GRAV3D is one software that can be used to solve 3D inversion problems of gravity data. Nevertheless there are still fundamental problems related to how to ensure the validity of GRAV3D to be used in 3D inversion. One approach used is to use lower bounds as inversion parameters. In this study lower bounds are set from  to . The results obtained show that the use of lower bounds decreases resulting in a larger data misfit which means that the more data that meets the tolerance calculation, the better recovered model produced.
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.
Mapping of pga value using psa method in West Halmahera North Maluku Rohima Wahyu Ningrum; Wiwit Suryanto; Hendra Fauzi; Estuning Tyas Wulan Mei
Jurnal Teknosains Vol 9, No 2 (2020): June
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/teknosains.41483

Abstract

The earthquake that occurred in the West Halmahera region was very detrimental, even though the human casualties were not very significant. But it will affect the stability and capacity of a region in terms of regional development. The mapping of earthquake-prone areas is carried out by a probabilistic seismic hazard analysis (PSHA) method to analyze soil movement parameters, namely Peak Ground Acceleration so that it can determine earthquake-prone areas in West Halmahera. The results of seismic hazard analysis show that the West Halmahera area is an area that is relatively prone to earthquake hazards because it is still strongly influenced by subduction (megathrust) earthquakes from the Philippine plate, Maluku sea and Sangihe. This is indicated by the value of earthquake acceleration on the Peak Ground Acceleration for the 500 year return period of around 0.38 - 3.69 g and 0.30 - 3.69 g for the 2500 year return period.
Microtremor Data to Strengthen the Students Mastery of Materials in the Implementation of Integrated Physics Learning Rohima Wahyu Ningrum; Hendra Fauzi; Wiwit Suryanto; Estuning Tyas Wulan Mei; Risky Nuri Amelia
Jurnal Penelitian Fisika dan Aplikasinya (JPFA) Vol. 10 No. 1 (2020)
Publisher : Universitas Negeri Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26740/jpfa.v10n1.p81-89

Abstract

A geophysical research has been conducted to determine the level of hazard vulnerability in West Halmahera by using microtremor data. Microtremor data are analyzed using the Horizontal to Vertical Spectral Ratio (HVSR) method and it is processed using Geopsy software to know hazard vulnerability level in the region . Data analysis and processing are used as sources of information in physics learning materials using an integrated learning model. Research objectives are to train the students to understand the materials in the fields of study and to enhance other discovery ideas.This research method uses the correlational method and the type of research is experimental research. The research design is an uniquecase research design and the instrument used is tests and questionnaires. The results of this research indicate that the microtremor data using integrated learning models of integrated types have effect on the students Mastery of materials in the implementation of physics learning. The effect of the integrated learning model of integrated type on the students Mastery of materials on the concepts of vibration and waves is 16% and it is in low category. Whereas, the students' responses to integrated learning model of integrated type are quite fun and it can help to improve their mastery of the material on the concepts of vibration and waves.
Dekomposisi Wavelet Data Seismik Broadband dari Stasiun Wanagama Yogyakarta pada saat Letusan Gunung Merapi 2010 D. Dairoh; Wiwit Suryanto
Jurnal Fisika dan Aplikasinya Vol 13, No 2 (2017)
Publisher : Lembaga Penelitian dan Pengabdian Kepada Masyarakat, LPPM-ITS

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (994.794 KB) | DOI: 10.12962/j24604682.v13i2.2157

Abstract

Letusan Merapi 2010 mengakibatkan kerusakan alat pengamatan seismik yang terpasang disekitar gunung Merapi. Penelitian ini bertujuan untuk meneliti karakteristik gempa vulkanik gunung Merapi dari daerah di luar bahaya gunungapi (stasiunWanagama). Analisis dilakukan dengan melakukan proses dekomposisi wavelet untuk memisahkan even gempa vulkanik dan noise yang terekam selama kurun waktu letusan gunung Merapi 2010. Proses dekomposisi dilakukan dengan menggunakan wavelet Daubechies orde 5. Intrepretasi dilakukan dengan melihat karaktersitik sinyal gempa vulkanik dengan kandungan frekuensi sinyal hasil dekomposisi tersebut. Dari hasil penelitian ini diperoleh informasi event gempa vulkanik yang terjadi selama letusan Merapi 2010.ABSTRACTEruption of mount Merapi in 2010 has caused damaged the seismic observation stations installed around mount Merapi. This research aimed to investigate the characteristics of Mount Merapi is volcanic earthquakes of the outside of volcanoes danger area(Wanagama station). The analysis was conducted by wavelet decomposition process to separate the noise volcanic and seismic events were recorded during the period of the eruption of Mount Merapi, 2010. The decomposition process was done by using wavelet Daubechies order of 5. Theinterpretation was made by looking at the characteristics of volcanic seismic signals with frequency content of the signal decomposition. From the results, the research shows event of volcanic earthquakes that occurred during the 2010 eruption of Merapi.
Statistical Comparison of IMERG Precipitation Products with Optical Rain Gauge Observations over Kototabang, Indonesia Helmi Yusnaini; Ravidho Ramadhan; Marzuki Marzuki; Ayu Putri Ningsih; Hiroyuki Hashiguchi; Toyoshi Shimomai; Mutya Vonnisa; Harmadi Harmadi; Wiwit Suryanto; Sholihun Sholihun
Jurnal Ilmu Fisika (JIF) Vol 14 No 1 (2022): March 2022
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jif.14.1.10-20.2022

Abstract

Satellite-based precipitation estimates play a crucial role in many hydrological and numerical weather models, especially to overcome the scarcity of rain gauge data. Globally gridded rainfall product from Integrated Multi-Satellite Retrievals for Global Precipitation Measurement (GPM) (IMERG) has been used in a wide range of hydrological applications. However, the IMERG is inherently prone to errors and biases. This study evaluated the performance of the IMERG-Final run (IMERG-F) product to estimate rainfall in a mountainous area of Sumatra. Validation was carried out using optical rain gauge (ORG) data for 15 years (2002-2016), at Kototabang, West Sumatra, Indonesia. In general, IMERG-F overestimated rainfall in all time scales. The longer the time scale was, the better the performance of IMERG-F we obtained. This feature was indicated by all quantities of continuous and categorical statistical matrices used. The performance of IMERG-F was lower than in other areas of the Maritime Continent, except for the probability of detection (POD) value. IMERG-F could detect rain very well, including for daily and hourly data, but the false alarm rate (FAR) was also relatively high. Such high FAR value may indicate a significant small-scale spatial rainfall variability in mountainous area of Sumatra.