Joint inversions of three types of electromagnetic data explicitly constrained by seismic observations: results from the central Okavango Delta, Botswana

The Okavango Delta of northern Botswana is one of the world’s largest inland deltas or megafans. To obtain information on the character of sediments and basement depths, audio-magnetotelluric (AMT) ...

[1]  G. W. Hohmann,et al.  4. Electromagnetic Theory for Geophysical Applications , 1987 .

[2]  A. Nur,et al.  Elasticity of High-porosity Sandstones: Theory For Two North Sea Datasets , 1995 .

[3]  Douglas W. Oldenburg,et al.  Inversion of controlled source audio-frequency magnetotellurics data for a horizontally layered earth , 1999 .

[4]  Andrea Viezzoli,et al.  Quantification of modeling errors in airborne TEM caused by inaccurate system description , 2011 .

[5]  David D. Jackson,et al.  Most squares inversion , 1976 .

[6]  T. McCarthy Groundwater in the wetlands of the Okavango Delta, Botswana, and its contribution to the structure and function of the ecosystem , 2006 .

[7]  Thomas Kalscheuer,et al.  Non-linear model error and resolution properties from two-dimensional single and joint inversions of direct current resistivity and radiomagnetotelluric data , 2010 .

[8]  Alan G. Jones The Magnetotelluric Method: Distortion of magnetotelluric data: its identification and removal , 2012 .

[9]  Peter Bauer-Gottwein,et al.  Regional review: the hydrology of the Okavango Delta, Botswana—processes, data and modelling , 2009 .

[10]  E. Atekwana,et al.  Rift kinematics during the incipient stages of continental extension: Evidence from the nascent Okavango rift basin, northwest Botswana , 2000 .

[11]  Imaging the continental upper mantle using electromagnetic methods , 1999 .

[12]  Esben Auken,et al.  Layered and laterally constrained 2D inversion of resistivity data , 2004 .

[13]  F. Nitsche,et al.  Late Quaternary depositional history of the Reuss delta, Switzerland: constraints from high‐resolution seismic reflection and georadar surveys , 2002 .

[14]  M. A. Meju,et al.  Iterative most-squares inversion: application to magnetotelluric data , 1992 .

[15]  P. Bauer‐Gottwein,et al.  Hydrogeophysical exploration of three-dimensional salinity anomalies with the time-domain electromagnetic method (TDEM) , 2010 .

[16]  T. McCarthy THE OKAVANGO DELTA AND ITS PLACE IN THE GEOMORPHOLOGICAL EVOLUTION OF SOUTHERN AFRICA , 2013 .

[17]  T. Kalscheuer,et al.  A hybrid regularization scheme for the inversion of magnetotelluric data from natural and controlled sources to layer and distortion parameters , 2012 .

[18]  A. Green,et al.  3-D high-resolution reflection seismic imaging of unconsolidated glacial and glaciolacustrine sediments: processing and interpretation , 2000 .

[19]  L. Rabenstein,et al.  Integrated interpretation of helicopter and ground-based geophysical data recorded within the Okavango Delta, Botswana , 2015 .

[20]  David S. G. Thomas,et al.  Mega-Lake in the Kalahari: A Late Pleistocene record of the Palaeolake Makgadikgadi system , 2009 .

[21]  Philip E. Wannamaker,et al.  Tensor CSAMT survey over the Sulphur Springs thermal area, Valles Caldera, New Mexico, U.S.A., Part II: Implications for CSAMT methodology , 1997 .

[22]  C. V. REEVES,et al.  Rifting in the Kalahari? , 1972, Nature.

[23]  Niels B. Christensen,et al.  Optimized fast Hankel transform filters , 1990 .

[24]  Robert Supper,et al.  Geoelectrical imaging of groundwater salinization in the Okavango Delta, Botswana , 2006 .

[25]  W. Ellery,et al.  The inorganic chemistry of peat from the Maunachira channel-swamp system, Okavango Delta, Botswana , 1989 .

[26]  Gerald W. Hohmann,et al.  Magnetotelluric responses of three-dimensional bodies in layered earths , 1984 .

[27]  Kenneth L. Zonge,et al.  9. Controlled Source Audio-Frequency Magnetotellurics , 1991 .

[28]  P. A. Larkin,et al.  Drainage evolution in south-central Africa since the breakup of Gondwana , 2001 .

[29]  Alan G. Jones,et al.  Atmospheric sources for audio-magnetotelluric (AMT) sounding , 2002 .

[30]  A. Chave Estimation of the magnetotelluric response function , 2012 .

[31]  Esben Auken,et al.  A resolution study of buried valleys using laterally constrained inversion of TEM data , 2008 .

[32]  T. Gumbricht,et al.  The topography of the Okavango Delta, Botswana, and its tectonic and sedimentological implications , 2001 .

[33]  Michael Commer,et al.  Electromagnetic evidence for an ancient avalanche caldera rim on the south flank of Mount Merapi, Indonesia , 2007 .

[34]  W. Kinzelbach,et al.  Constraining helicopter electromagnetic models of the Okavango Delta with seismic-refraction and seismic-reflection data , 2014 .

[35]  T. McCarthy,et al.  The influence of neo-tectonics on water dispersal in the northeastern regions of the Okavango swamps, Botswana , 1993 .

[36]  James Macnae,et al.  6. Time Domain Electromagnetic Prospecting Methods , 1991 .

[37]  E. Auken,et al.  Inversion of band‐limited TEM responses , 1999 .

[38]  Alan G. Jones,et al.  The magnetotelluric method : theory and practice , 2012 .

[39]  W. Kinzelbach,et al.  Paleo-megalake and paleo-megafan in southern Africa , 2013 .

[40]  Mehrdad Bastani,et al.  EnviroMT : A new controlled source/radio magnetotoelluric system , 2001 .

[41]  S. Treitel,et al.  A REVIEW OF LEAST-SQUARES INVERSION AND ITS APPLICATION TO GEOPHYSICAL PROBLEMS* , 1984 .

[42]  Amos Nur,et al.  COMPRESSIONAL VELOCITY AND POROSITY IN SAND-CLAY MIXTURES , 1992 .

[43]  E. Atekwana,et al.  Fault growth and propagation during incipient continental rifting: Insights from a combined aeromagnetic and Shuttle Radar Topography Mission digital elevation model investigation of the Okavango Rift Zone, northwest Botswana , 2008 .

[44]  T. Mukerji,et al.  The Rock Physics Handbook , 1998 .

[45]  Michael W. Asten,et al.  Full transmitter waveform transient electromagnetic modeling and inversion for soundings over coal measures , 1987 .

[46]  Brian R. Spies,et al.  Depth of investigation in electromagnetic sounding methods , 1989 .

[47]  P. Shaw,et al.  Geomorphology, sedimentation, and tectonics in the Kalahari Rift , 1992 .

[48]  Juergen H. Schön,et al.  Physical Properties of Rocks: A Workbook , 2011 .

[49]  A. Green,et al.  Shallow seismic reflection study of a glaciated valley , 1998 .

[50]  K. Vozoff,et al.  The joint use of coincident loop transient electromagnetic and Schlumberger sounding to resolve layered structures , 1985 .

[51]  Alan G. Jones Electromagnetic interrogation of the anisotropic Earth: Looking into the Earth with polarized spectacles , 2006 .

[52]  David L.B. Jupp,et al.  Joint Inversion of Geophysical Data , 2007 .

[53]  J. Wright,et al.  Tensor CSAMT studies at the Buchans Mine in central Newfoundland , 1993 .

[54]  S. Ringrose,et al.  Diagenesis in Okavango fan and adjacent dune deposits with implications for the record of palaeo-environmental change in Makgadikgadi–Okavango–Zambezi basin, northern Botswana , 2008 .

[55]  Misac N. Nabighian,et al.  Electromagnetic Methods in Applied Geophysics , 1988 .

[56]  J. Patchett An Investigation Of Shale Conductivity , 1975 .

[57]  David E. Boerner,et al.  Electric and magnetic galvanic distortion decomposition of tensor CSAMT data. Application to data from the Buchans Mine (Newfoundland, Canada) , 2003 .

[58]  Thomas Kalscheuer,et al.  A non-linear truncated SVD variance and resolution analysis of two-dimensional magnetotelluric models , 2007 .

[59]  Alan G. Green,et al.  Hydrogeophysical investigations in the western and north-central Okavango Delta (Botswana) based on helicopter and ground-based transient electromagnetic data and electrical resistance tomography , 2014 .

[60]  L. Cathles,et al.  Electrical conductivity in shaly sands with geophysical applications , 1998 .

[61]  W. Kinzelbach,et al.  Okavango Delta Islands: Interaction between density-driven flow and geochemical reactions under evapo-concentration , 2007 .

[62]  C. Scholz,et al.  Evidence for Incipient Rifting in Southern Africa , 1976 .

[63]  R. Parker,et al.  Occam's inversion; a practical algorithm for generating smooth models from electromagnetic sounding data , 1987 .

[64]  M. Descloîtres,et al.  Mapping Coastal Aquifers by Joint Inversion of DC and TEM Soundings‐Three Case Histories , 2001 .

[65]  Amos Nur,et al.  Elasticity of high‐porosity sandstones: Theory for two North Sea data sets , 1996 .

[66]  F. Cotterill,et al.  THE EVOLUTION AND AGES OF MAKGADIKGADI PALAEO-LAKES: CONSILIENT EVIDENCE FROM KALAHARI DRAINAGE EVOLUTION SOUTH-CENTRAL AFRICA , 2012 .

[67]  T. McCarthy,et al.  Groundwater evolution, chemical sedimentation and carbonate brine formation on an island in the Okavango Delta swamp, Botswana , 1991 .

[68]  W. Kinzelbach,et al.  Salt transport on islands in the Okavango Delta: Numerical investigations , 2006 .

[69]  K. Vozoff,et al.  8. The Magnetotelluric Method , 1991 .

[70]  Walter L. Anderson,et al.  Effect of transmitter turn-off time on transient soundings , 1987 .

[71]  Max A. Meju,et al.  Biased estimation: a simple framework for inversion and uncertainty analysis with prior information , 1994 .

[72]  David S. G. Thomas,et al.  The Kalahari environment , 1992 .

[73]  A. Christiansen,et al.  Processing and inversion of commercial helicopter time-domain electromagnetic data for environmental assessments and geologic and hydrologic mapping , 2013 .

[74]  B. Sternberg The variability of naturally occurring magnetic field levels: 10 Hz to 8 kHz , 2010 .

[75]  H. Beckmann,et al.  Logging the sea floor with bore hole logging systems. [Adaptation of conventional systems to bottom trail logging; review] , 1975 .

[76]  Vladimir I. Dmitriev,et al.  Models and Methods of Magnetotellurics , 2008 .

[77]  R. C. Bailey,et al.  Inversion of the geomagnetic induction problem , 1970, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[78]  Robert Piessens,et al.  Quadpack: A Subroutine Package for Automatic Integration , 2011 .

[79]  T. McCarthy,et al.  CHEMICAL SEDIMENTATION IN THE SEMI-ARID ENVIRONMENT OF THE OKAVANGO DELTA,BOTSWANA , 1990 .

[80]  L. Pedersen,et al.  Controlled source tensor magnetotellurics , 1991 .