Inverse Modeling of Gravity Data with Two Layers Density in Sedimentary Basin Structure

Wahyudi, Eko Januari; Kadir, Wawan Gunawan A.

doi:10.1088/1742-6596/1090/1/012048

Cited by 3 publications

(6 citation statements)

References 16 publications

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“…The calculation of calculated data conducted using the equation described by Plouff [1]. The thickness of sedimentary layer (dz(j)) will be updated as solution using simple formulation (with modification from previous work [2]), as follow:…”

Section: Gravity Modeling Using Interface Density Inversionmentioning

confidence: 99%

“…Next, we describe the modeling of the study area using iterative calculation, as mentioned previously in the methodology part. Considering preliminary study [2] and well data, the input (density contrast) of the first (upper) layer is -0.10 g/cc and the input (density contrast) of the second (lower) layer is +0.10 g/cc. We calculate with 100 realizations to provide an average solutions from the statistical experiments using a random number.…”

Section: Gravity Modeling Using Interface Density Inversionmentioning

confidence: 99%

“…The solution of the interface between the basement-sedimentary layer (first interface) is iteratively computed using 200 times of iteration number for each realization. Vertical prisms dimension (dx and dy) used in the modeling are 250 m. Considering preliminary study [2], residual anomaly and topographic data as input. Residual anomaly variation shows subsurface correlation as well as the seismic data [3].…”

Section: Gravity Modeling Using Interface Density Inversionmentioning

confidence: 99%

“…In the calculation of calculated data from TEM using the forward modeling equation written in equation (2) will generate data in the frequency domain (Hz). The inverse Fourier transform technique can be applied to transform from calculated data into the time-domain.…”

Section: Tdem Modelingmentioning

confidence: 99%

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Subsurface Modeling using Gravity and TDEM in Jiken, Blora Regency

Aji

Wahyudi

Warsa

2022

IOP Conf. Ser.: Earth Environ. Sci.

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Geophysics plays an essential role in imaging the subsurface condition of the earth. Gravity and time-domain electromagnetic method is geophysical method that can be used to visualize the subsurface condition. In this research, gravity and TDEM surveys have been carried out in Jiken, Blora Regency. Modeling technique is needed to obtain the subsurface model that bring information related to subsurface condition. Inversion modeling is applied separately to the gravity data and TDEM data, respectively. The density interface inversion modeling is used to gravity data.Subsurface condition is approached by three layers model with different density contrast values in each layer. In these schemes, the modeling process will determine the thickness for every layer. While for TDEM modeling,differential evolution technique is applied to model the TDEM data. The subsurface condition is approached by four layers model. In these schemes, the modeling process will determine the resistivity and thickness for every layer. Finally, the model obtained from gravity inversion modeling is integrated into the model from TDEM inversion data by overlaying the model.

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Section: Gravity Modeling Using Interface Density Inversionmentioning

confidence: 99%

Section: Gravity Modeling Using Interface Density Inversionmentioning

confidence: 99%

Section: Gravity Modeling Using Interface Density Inversionmentioning

confidence: 99%

Section: Tdem Modelingmentioning

confidence: 99%

See 2 more Smart Citations

Subsurface Modeling using Gravity and TDEM in Jiken, Blora Regency

Aji

Wahyudi

Warsa

2022

IOP Conf. Ser.: Earth Environ. Sci.

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“…The slice section (SW-NE) from figure 4 is illustrated in figure 5. The forward calculation using a set of rectangular prism can be calculated using Pluoff equation [9] that extensively used in several study (such as: [10], [11], [12], and [13]). The more general of matrix notation of forward calculation for synthetic data (d) with model parameter (𝒎) can also be expressed as follow:…”

Section: Inverse Modelingmentioning

confidence: 99%

Gravity data processing of field camp geophysics in Karangsambung (2005-2019)

Wahyudi

Laesanpura

Aji

2022

J. Phys.: Conf. Ser.

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Gravity data was collected from a previous survey in Karangsambung 2005-2019 (before the restriction of field camp activities due to the Covid-19 pandemic). Luk-Ulo Mélange Complex in the Karangsambung area has been the subject of local and regional studies for geoscience students due to the interesting exposure of outcrops that have been interpreted as product of subduction (the Indo-Australian plate under the Eurasian plate in the Late Cretaceous to Early Paleocene time). The data for this gravimetric study based on 2592 observations over an area of inside (9.1 × 9.1) square kilometers. The gravity data were observed by students in the field camps for several years and then we compile. In this work we present simple data processing and simple calculation for modeling. The Bouguer anomaly map was processed using a density estimate of 2.31 g/cc for slab-Bouguer and terrain correction/reduction. The residual anomaly map was obtained by simple calculation of trend surface analysis (second order polynomial order). The inverse model was calculated using a simple algorithm for 2.5D and the program was built by accomodate topographic variations in the study area. Slice sections (SW-NE) of residual anomalies with a length of more than 8 km were inverted to obtain the contrast density distribution as a subsurface model. The subsurface images can then be analyzed and correlated with geological surface maps in the study area. The work in this paper is mainly presented as an ilustration of simple data processing and inverse modeling, so that the outcomes of this work are: (1) Bouguer anomaly map, (2) residual anomaly map, and (3) contrast density distribution as SW-NE section in the Karangsambung area. The value of the Bouguer anomaly map from this study is in the range of 88 to 112 mGal, and the value of the residual anomaly map is in the range of -12 to 10 mGal. The contrast density distribution from the inverse model in this study is in the range of -0.3 to 0.6 g/cc.

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Pemodelan Time-Lapse Microgravity Untuk Estimasi Perubahan Muka Airtanah Di Bandung, Jawa Barat

Wahyudi,

A. Kadir,

Alawiyah

et al. 2023

JSDA

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Studies related to groundwater monitoring using geophysical methods have been carried out since the 1990s. Surface gavity data with a scheme of relative gravimeter measurements is chosen for monitoring in urban areas because it is quite fast, easy, affordable, and relatively low-impact on the environment. The significance of the time-lapse microgravity method for the target of this study depends on changes in the mass of water in the aquifer layer below the surface. The research area in this study covers the city of Bandung and several surrounding areas with an interpolated grid coverage of (18 x 17) km2. Gravity changes were determined by six repeated surveys at the same observation points from 2010 to 2021. The aim of this research is to develop a method for estimating groundwater table changes based on time-lapse microgravity data modeling. The complexity of subsurface density changes is simplified for two parts related to near surface density changes and density changes in the intermediate aquifer layer. The trend of groundwater table data in 2010 is used as a reference to determine estimates for 2015, 2016 (February and August), 2019, and 2021. Modeling results for intermediate aquifers (confined groundwater system) provide changes in groundwater levels from 2010 with estimates reached ±23 meters, while the results of modeling at near surface (shallow groundwater level) indicate a groundwater level change of approximately ±8 meters from the year 2010.Keywords: microgravity, groundwater, modeling, hydrology, aquifer. ABSTRAKStudi terkait pemantauan airtanah dengan metode geofisika telah dilakukan sejak tahun 1990-an. Data gravity di permukaan dengan skema pengukuran gravimeter relatif dipilih pada pemantauan di area perkotaan karena cukup cepat, mudah, murah, dan relatif tidak merusak lingkungan. Signifikansi metode time-lapse microgravity pada target studi ini bergantung pada perubahan massa air pada lapisan akuifer di bawah permukaan. Area penelitian pada studi ini mencakup Kota Bandung dan beberapa area di sekitarnya dengan cakupan luasan interpolasi grid (18 x 17) km2. Perubahan gravitasi ditentukan oleh enam kali survei berulang pada beberapa titik pengamatan yang sama sejak 2010 sampai 2021. Tujuan dari penelitian ini adalah mengembangkan metode untuk mengestimasi perubahan muka airtanah berdasarkan pemodelan data time-lapse microgravity. Kompleksitas perubahan densitas di bawah permukaan disederhanakan untuk dua bagian terkait perubahan densitas dekat permukaan dan perubahan densitas pada lapisan akuifer menengah. Kecenderungan dari data muka airtanah pada tahun 2010 digunakan sebagai acuan untuk menentukan estimasi pada tahun 2015, 2016 (Februari dan Agustus), 2019, dan 2021. Hasil pemodelan pada akuifer menengah (sistem airtanah tertekan) memberikan perubahan muka airtanah dari tahun 2010 dengan estimasi mencapai ±23 meter, sedangkan hasil pemodelan pada kedalaman yang lebih dangkal (muka airtanah dangkal) menunjukkan perubahan muka airtanah mencapai ±8 meter dari tahun 2010.Kata Kunci: microgravity, airtanah, pemodelan, hidrologi, akuifer

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Inverse Modeling of Gravity Data with Two Layers Density in Sedimentary Basin Structure

Cited by 3 publications

References 16 publications

Subsurface Modeling using Gravity and TDEM in Jiken, Blora Regency

Subsurface Modeling using Gravity and TDEM in Jiken, Blora Regency

Gravity data processing of field camp geophysics in Karangsambung (2005-2019)

Pemodelan Time-Lapse Microgravity Untuk Estimasi Perubahan Muka Airtanah Di Bandung, Jawa Barat

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