A Sediment Thickness Map of South America Using Automated Inversion of Magnetic and Gravity Data for Depth to Basement

2011 ◽  
Author(s):  
Mark E. Odegard
Keyword(s):  
South America ◽  
Gravity Data ◽  
Sediment Thickness

scholarly journals ESTIMASI KETEBALAN SEDIMEN DENGAN ANALISIS POWER SPECTRAL PADA DATA ANOMALI GAYABERAT

GEOMATIKA ◽  
2018 ◽  
Vol 23 (2) ◽  
pp. 65 ◽  
Author(s):  
Mila Apriani ◽  
Admiral Musa Julius ◽  
Mahmud Yusuf ◽  
Damianus Tri Heryanto ◽  
Agus Marsono
Keyword(s):  
Spectral Analysis ◽  
Fourier Transform ◽  
Gravity Anomaly ◽  
Spectral Method ◽  
Gravity Data ◽  
Sediment Thickness ◽  
Transform Method ◽  
Fourier Transform Method ◽  
Power Spectral ◽  
The Fourier Transform

<p align="center"><strong>ABSTRAK</strong></p><p> </p><p>Penelitian dengan analisis <em>power spectral</em> data anomali gayaberat telah banyak dilakukan untuk estimasi ketebalan sedimen. Dalam studi ini penulis melakukan analisis spektral data anomali gayaberat wilayah DKI Jakarta untuk mengetahui kedalaman sumber anomali yang bersesuaian dengan ketebalan sedimen. Data yang digunakan berupa data gayaberat dari BMKG tahun 2014 dengan 197 lokasi titik pengukuran yang tersebar di koordinat 6,08º-6,36º LU dan 106,68º-106,97º BT. Studi ini menggunakan metode <em>power spectral</em>  dengan mentransformasikan data dari domain jarak ke dalam domain bilangan gelombang memanfaatkan transformasi <em>Fourier</em>. Hasil penelitian dengan menggunakan metode transformasi <em>Fourier  </em>menunjukkan bahwa ketebalan sedimen di Jakarta dari arah selatan ke utara semakin besar, di sekitar Babakan ketebalan diperkirakan 92 meter, sekitar Tongkol, Jakarta Utara diperkirakan 331 meter.</p><p><strong> </strong></p><p><strong>Kata kunci</strong>: <em>power spectral</em>, anomali gayaberat, ketebalan sedimen</p><p align="center"><strong><em> </em></strong></p><p align="center"><strong><em>ABSTRACT</em></strong></p><p><em> </em></p><p><em>Studies of spectral analysis of gravity anomaly data have been carried out to estimate the thickness of sediment. In this study the author did spectral analysis of gravity anomaly data of DKI Jakarta area to know the depth of anomaly source which corresponds to the thickness of sediment. The data used in the form of gravity data from BMKG 2014 with 197 locations of measurement points spread in coordinates 6.08º - 6.36º N and 106.68º - 106.97º E. This study used the power spectral method by transforming the data from the distance domain into the wavenumber domain utilizing the Fourier transform. The result of the research using Fourier transform method shows that the thickness of sediment in Jakarta from south to north is getting bigger, in Babakan the thickness of the sediment is around 92 meter, in Tongkol, North Jakarta is around 331 meter.</em></p><p><strong><em> </em></strong></p><p><strong><em>Keywords</em></strong><em>: </em><em>power spectral, gravity anomaly, sediment thickness</em><em></em></p>

Elastic thickness structure of South America estimated using wavelets and satellite-derived gravity data

2007 ◽  
Vol 253 (1-2) ◽  
pp. 17-36 ◽  
Author(s):  
Andrés Tassara ◽  
Chris Swain ◽  
Ron Hackney ◽  
Jon Kirby
Keyword(s):  
South America ◽  
Gravity Data

Sediment thickness, basement structure and tectonics from inversion and modeling over northeastern South America

2005 ◽  
Author(s):  
Mark E. Odegard ◽  
Allan E. Kean ◽  
W. Robert Weber ◽  
Kirsten Fletcher ◽  
Mohammed Kidwai
Keyword(s):  
South America ◽  
Sediment Thickness ◽  
Basement Structure

A deterministic approach toward isostatic gravity residuals—A case study from South America

Geophysics ◽  
1996 ◽  
Vol 61 (4) ◽  
pp. 1022-1033 ◽  
Author(s):  
David A. Chapin
Keyword(s):  
South America ◽  
Gravity Data ◽  
Crustal Thickness ◽  
Crustal Thickening ◽  
Density Contrast ◽  
Data Sets ◽  
Topographic Effects ◽  
Continental Scale ◽  
Free Air ◽  
Free Air Gravity

A new deterministic method for correcting isostatic effects in gravity data sets overcomes the deficiencies of empirically based methods. This technique produces a superior gravity image for South America and has application to other continental‐scale gravity data sets. The basis for the correction is the Airy‐Heiskanen isostatic model, which assumes that surface topography is supported by crustal thickening. The three key parameters, (1) the crustal thickness at sea‐level, (2) the surface reduction density, and (3) the density contrast between the crust and the mantle, are determined directly from the elevation, free‐air gravity, and Bouguer gravity data sets. The surface density parameter of 2.60 g/cc is determined using a new fractal technique. This technique assumes that the topography is fractal. The best value for density is that which minimizes the fractal component caused by topographic effects. The new value is substantially different than the 2.67 g/cc density assumed by many previous workers for most continental‐scale data sets. The crust/mantle density contrast parameter of 0.45 g/cc is determined by comparison between the densities determined from crossplots of the Bouguer values versus elevation. The crustal thickness parameter of 30 km is determined using a spectral method applied to the free‐air gravity. The results of this work are not only an isostatic residual map, but a methodology that cross checks the data for quality control. The final isostatic residual map can be used with confidence for basin evaluation throughout the continent of South America. Basins at high elevations, like the eastern foreland basins of the Andes and the Altiplano Basin, are imaged better by using this method.

scholarly journals METODA PSEUDO-GRAVITY DALAM ANALISIS KELURUSAN DAN PATAHAN DI SEKITAR TINGGIAN ASAHAN, PERAIRAN SELAT MALAKA.

2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Subarsyah Subarsyah ◽  
Yusuf Adam Priohandono
Keyword(s):  
Field Theory ◽  
Potential Field ◽  
Gravity Data ◽  
Secondary Data ◽  
Negative Polarity ◽  
Original Data ◽  
Magnetic Data ◽  
Magnetic Method ◽  
Sediment Thickness ◽  
Key Words Transformation

Melalui teori medan dalam metoda magnetik dan gaya berat, ambiguitas yang muncul merupakan suatu faktor yang menyulitkan dalam penerapan kedua metoda ini. Terlebih pada penerapan metoda magnetik yang memiliki efek polaritas positif dan negatif. Beberapa teknik dan metoda telah diterapkan dalam melakukan analisis dan pengolahan data anomali magnet untuk mengatasi masalah ambigutas ini dengan tujuan mempermudah dalam melakukan interpretasi. Salah satu metodanya yaitu transformasi data anomali magnet ke dalam data pseudo-gravity. Metoda ini akan diterapkan dalam analisis dan pengolahan data anomali magnet di sekitar Tinggian Asahan dalam hal ini untuk menganalisis kelurusan dan patahan yang muncul di area ini. Hasil transformasi akan dibandingkan dengan data skunder berupa ketebalan sedimen dan patahan di area yang sama. Hasil penerapan metoda ini memperlihatkan adanya indikasi kelurusan ataupun patahan muncul, yang tidak terlihat jelas pada data aslinya yaitu anomali magnet. Kata Kunci : Transformasi, Pseudo-Gravity, Tinggian Asahan. Through potential field theory in magnetic and gravity methods, ambiguity that presented is the difficult factor in the application of both methods. Moreover the application of magnetic method which involve the effect of positive and negative polarity are more complicated. Some techniques and methods have been used to overcome problem of ambiguity in order to make easier interpretation. One of the techniques is the transformation from anomaly magnetic to pseudo-gravity data. This method will be used within analysis and processing anomaly magnetic data at Asahan Arch to analyze lineaments and faults that appear in this area. Transformation result will be compared with another data which is secondary data about sediment thickness and fault at the same area. This technique shows that indication of fault more clearly than the original data or anomaly magnetic data. Key Words: Transformation, Pseudo-Gravity, Asahan High.

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