Archive for category Publications

Advances in Airborne and Ground Geophysical Methods for Uranium Exploration

Posted by AP on Tuesday, 30 April, 2013

IAEA (International Atomic Energy Agency) has published a book “Advances in Airborne and Ground Geophysical Methods for Uranium Exploration”.

“Due to growing global energy demand, many countries have seen a rise in uranium exploration activities in the past few years, and newly designed geophysical instruments and their application in uranium exploration are contributing to an increased probability of successful discoveries. This publication highlights advances in airborne and ground geophysical techniques and methods for uranium exploration, succinctly describing modern geophysical methods and demonstrating their application with examples.”

Download..


New Geophysical Articles on Earth Explorer

Posted by AP on Monday, 11 March, 2013

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The new gravity books

Posted by AP on Sunday, 3 March, 2013

Acquisition and Analysis of Terrestrial Gravity Data

  • Leland Timothy Long, Georgia Institute of Technology
  • Ronald Douglas Kaufmann, Spotlight Geophysical Services

Gravity surveys have a huge range of applications, indicating density variations in the subsurface and identifying man-made structures, local changes of rock type or even deep-seated structures at the crust/mantle boundary. This important one-stop book combines an introductory manual of practical procedures with a full explanation of analysis techniques, enabling students, geophysicists, geologists and engineers to understand the methodology, applications and limitations of a gravity survey. Filled with examples from a wide variety of acquisition problems, the book instructs students in avoiding common mistakes and misconceptions. It explores the increasing near-surface geophysical applications being opened up by improvements in instrumentation and provides more advance-level material as a useful introduction to potential theory. This is a key text for graduate students of geophysics and for professionals using gravity surveys, from civil engineers and archaeologists to oil and mineral prospectors and geophysicists seeking to learn more about the Earth’s deep interior.

Author(s)/Editor(s):Thomas R. LaFehr and Misac N. Nabighian

Fundamentals of Gravity Exploration (Geophysical Monograph Series No. 17) covers a full range of gravity-exploration topics, including first principles, field instrumentation and operations, rock densities and density contrasts, data reduction, methods of interpretation, and geologic examples.  The subject matter includes inversion and an appendix on the Fourier transform.  This book will help students to efficiently gain knowledge and appreciation for the method, and it will provide experienced earth scientists with a valuable addition to their exploration libraries, both for reference and understanding of this important method.


Potential fields for basement investigations

Posted by AP on Wednesday, 30 January, 2013

Often not given its due in oil and gas geophysics, knowledge of basement geology can be critical to exploiting reservoirs including the unconventional.

by GRAHAM CHANDLER on JANUARY 24, 2013

There is an article in the last Earth Explorer issue:

New Approach to Basement Studies for Oil and Gas Explorers



The New Near-surface Resistivity Method

Posted by AP on Monday, 22 October, 2012

“The Leading Edge” has published in October 2012 issue the article of  Roy K. Warren, Warren Geophysical Service (Houston, TX), “Near-surface resistivity for hydrocarbon detection”. The article consists of many case studies which demonstrate the accuracy of the results.

Abstract

Roy K. Warren
Warren Geophysical Service
A new method called the “grid resistivity system” (GRS) is described which measures relative changes in subsurface resistivity using the low-frequency harmonics (either 50 or 60 Hz) generated by electric power lines. The electromagnetic waves emanate from the power grid, and some of this energy interacts with the air-Earth interface to be absorbed by the Earth. The lowest frequency penetrates to the greatest depth. The power from the grid causes current to flow in the rocks and soil. The Earth material with higher conductivity offers a path for the current to follow. The method can help locate geophysical signatures associated with the geochemical response of hydrocarbon chimney leakage. Data collection is fast and low cost. Processing results in cross sections of resistivity. Interpretation focuses on the identification of the larger conductors related to clay alteration caused by chimney leakage from a reservoir. ©2012 Society of Exploration Geophysicists

Seismoelectric & Microgravity in the last FastTIMES issue

Posted by AP on Tuesday, 9 October, 2012

The EEGS has published the latest issue of FastTIMES, news for the near-surface geophysical sciences. It is available as a pdf document optimized for screen viewing or printing.

Seismoelectric & Microgravity

Volume 17, Number 2, June 2012


Environmental Geophysics: Everything you ever wanted to know

Posted by AP on Monday, 10 September, 2012


Bookshop Offer from EAGE

Environmental Geophysics: Everything you ever wanted (needed!) to know but were afraid to ask! (EET7)

Written by, Peter Styles

This is an outward facing book for people who need to understand Geophysics. It can solve the problems they regularly encounter and help them to deliver their optimal geotechnical solution, proved by the essential, but last to be applied, intrusive investigation.


Geoscience Australia: update on geophysical data

Posted by AP on Friday, 7 September, 2012

Update on geophysical data releases

Geoscience Australia will be managing the data acquisition program in New South Wales, Queensland, Western Australia and the Northern Territory.

The current status of Geoscience Australia’s geophysical survey data acquisition is available in a comprehensive table.

Minerals Alert Geophysical Surveys Table – survey boundary polygons in MapInfo TAB format.

Seismic and magnetotelluric data released for Youanmi Survey in Western Australia

The Youanmi deep crustal seismic survey was acquired in 2010 and extends nearly 700 kilometres over the Youanmi Terrane and Eastern Goldfields Superterrane of the Yilgarn Craton. This project was a collaboration between Geoscience Australia and the Geological Survey of Western Australia (GSWA). Funding was provided from the Western Australian Government’s Exploration Incentive Scheme, and Geoscience Australia’s Onshore Energy Security Program. The survey consists of three traverses with a total length of 695 kilometres. These seismic, magnetotelluric and gravity data aim to image the northern Yilgarn Craton from its north-western margin to the Ida Fault, near Leinster.

These data combined with the 2001 Northern Yilgarn and the 2010 Capricorn deep crustal reflection surveys result in a complete section across the northern Yilgarn Craton.

The processed SEG Y data, TIFF images, location information, magnetotelluric and gravity data are available and can be downloaded from the Seismic Acquisition and Processing project.

Interpretations of the seismic sections and magnetotelluric models undertaken by GSWA and Geoscience Australia geologists will be released in February 2013 at a public workshop in Perth.


2012 CSEG Webcasts

Posted by AP on Tuesday, 28 August, 2012

Webcast viewing guide

Technical Luncheon Webcasts

Lee Hunt

January 23, 2012
Quantitative Interpretation, New Challenges, and Economic Value
Lee Hunt
Flash Version MP4 Version


Dr. Mike Kendall

February 29, 2012
Rifting in Africa: Seismological Views from Afar
Dr. Mike Kendall
Flash Version MP4 Version


Shawn Maxwell

April 23, 2012
Microseismic Imaging of Hydraulic Fractures: Snap, Crackle and Pops of Shale Reservoirs
Shawn Maxwell
Flash Version MP4 Version


Lunchbox Geophysics Webcasts

January 31, 2012
Texture Analysis of High Resolution Aeromagnetic Data to Delineate Geological Features in the Horn River Basin, NE British Columbia
Hassan H. Hassan, Fugro Gravity and Magnetic Services
Flash Version MP4 Version


March 7, 2012
Cost efficient acquisition to reduce coarse land 3D line spacings through beyond Nyquist interpolation
Bill Goodway
Flash Version MP4 Version


“New Achievements in Geoscience”

Posted by AP on Wednesday, 22 August, 2012

INTECH (Open Science|Open MInds) has published a book “New Achievements in Geoscience” under editing of

Dr. Hwee-San Lim. The first four chapters are dedicated to geophysical methods:


Some articles in the last “Computer & Geoscience” issue for geophysicists (Volume 46 2012)

Posted by AP on Sunday, 15 July, 2012

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CNNEDGEPOT: CNN based edge detection of 2D near surface potential field data

Original Research Article
Pages 1-8
D. Aydogan

Highlights

► Edge detection plays an important role in the image processing. ► Cellular neural network was proposed for the extraction of sources and edges. ► A MATLAB code was prepared. ► It was implemented on the potential field data.

A graphical user interface application for evaluation of the gravitational tensor components generated by a level ellipsoid of revolution

Original Research Article
Pages 77-83
Michal Šprlák

Highlights

► We offer a software application for evaluation of the normal gravitational tensor. ► Several computational modes and an easy-to-use GUI have been developed. ► The software is convenient for satellite gravitational gradiometry applications.

GICUDA: A parallel program for 3D correlation imaging of large scale gravity and gravity gradiometry data on graphics processing units with CUDA

Original Research Article
Pages 119-128
Zhaoxi Chen, Xiaohong Meng, Lianghui Guo, Guofeng Liu

Highlights

► Introduce 3D correlation imaging for gravity and gravity gradiometry data. ► Introduce GPU parallel computing with CUDA using NVIDIA video cards. ► Analyze the characteristics of GPU and 3D correlation imaging. ► Present GICUDA implementation entirely on GPUs with CUDA.


Some informal notes from the EAGE workshop

Posted by AP on Tuesday, 12 June, 2012

MATT HALL: ”This year is the 20th anniversary of the release of Seismic Un*x as free software. It is six years since the first open software workshop at EAGE. And it is one year since the PTTC open source geoscience workshop in Houston, where I first met Karl Schleicher, Joe Dellinger, and a host of other open source advocates and developers. The EAGE workshop on Friday looked back on all of this, surveyed the current landscape, and looked forward to an ever-increasing rate of invention and implementation of free and open geophysics software.

Rather than attempting any deep commentary, here’s a rundown of the entire day:..”

Read more


2012 Exploration trends and Developments

Posted by AP on Wednesday, 30 May, 2012

The annual “Exploration trends and developments” magazine is on-line:

http://kegsonline.org/attachments/trends/TrendsIn2011_by_P_Killeen-TheNorthernMinerMarch2012.pdf

“The Trends review originated with the Geological Survey of Canada (GSC), where, for over 45 years, GSC scientists
have prepared an unbiased annual publication on trends and new developments in geophysical exploration for minerals.”

A MATLAB program to invert the gravity anomaly

Posted by AP on Tuesday, 14 February, 2012

3DINVER.M: A MATLAB program to invert the gravity anomaly over a 3-D horizontal density interface by Parker-Oldenburg’s algorithm.

David Gómez Ortiz and Bhrigu N P Agarwal

A MATLAB source code 3DINVER.M is described to compute 3D geometry of a horizontal density interface from gridded gravity anomaly by Parker-Oldenburg iterative method. This procedure is based on a relationship between the Fourier transform of the gravity anomaly and the sum of the Fourier transform of the interface topography.  Given the mean depth of the density interface and the density contrast between the two media, the three-dimensional geometry of the interface is iteratively calculated. The iterative process is terminated when either the RMS error between two successive approximations is lower than a pre-assigned value- used as convergence criterion, or until a pre-assigned maximum number of iterations is reached. A high-cut filter in the frequency domain has been incorporated to enhance the convergence in the iterative process. The algorithm is capable of handling large data sets requiring direct and inverse Fourier transforms effectively. The inversion of a gravity anomaly over Brittany (France) is presented to compute the Moho depth as a practical example.

Download MATLAB code and data file examples


“Black magic in geophysical prospecting” – 75 years ago

Posted by AP on Thursday, 8 September, 2011

Blau, L (1936). Black magic in geophysical prospecting. Geophysics 1 (1).

Agile: “If you are an exploration geoscientist, you must read it. Then go and get someone else to read it too.

It’s all about how to spot a nut, detect hidden whisky, and fail to find oil with sexual emanations”.


Some e-books for exploration geophysicists

Posted by AP on Saturday, 3 September, 2011


The new issue of Bulletin of the Australian Society of Exploration Geophysicists

Posted by AP on Friday, 2 September, 2011

Volume 42(3) 2011

Contents

Airborne electromagnetic bathymetry investigations in Port Lincoln, South Australia – comparison with an equivalent floating transient electromagnetic system

Julian Vrbancich
Abstract |

3D acoustic wave modelling with time-space domain dispersion-relation-based finite-difference schemes and hybrid absorbing boundary conditions

Yang Liu and Mrinal K. Sen
Abstract |

Using potential field data for petroleum exploration targeting, Amadeus Basin, Australia

Mike Dentith and Duncan Cowan
Abstract |

Joint processing of total-field and gradient magnetic data

Kristofer Davis and Yaoguo Li
Abstract |

Comments on: Palmer, D., 2010. Is visual interactive ray trace an efficacious strategy for refraction inversion? Exploration Geophysics, 41, 260–267

Robert J. Whiteley

Response to comments by Robert J. Whiteley on: Palmer, D., 2010. Is visual interactive ray trace an efficacious strategy for refraction inversion? Exploration Geophysics, 41, 260–267 *

Derecke Palmer