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- W2095794777 abstract "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, audiomagnetotelluric (AMT), controlled-source audiomagnetotelluric (CSAMT) and central-loop transient electromagnetic (TEM) data were collected on the largest island within the delta. The data were inverted individually and jointly for 1-D models of electric resistivity. Distortion effects in the AMT and CSAMT data were accounted for by including galvanic distortion tensors as free parameters in the inversions. By employing Marquardt–Levenberg inversion, we found that a 3-layer model comprising a resistive layer overlying sequentially a conductive layer and a deeper resistive layer was sufficient to explain all of the electromagnetic data. However, the top of the basal resistive layer from electromagnetic-only inversions was much shallower than the well-determined basement depth observed in high-quality seismic reflection images and seismic refraction velocity tomograms. To resolve this discrepancy, we jointly inverted the electromagnetic data for 4-layer models by including seismic depths to an interface between sedimentary units and to basement as explicit a priori constraints. We have also estimated the interconnected porosities, clay contents and pore-fluid resistivities of the sedimentary units from their electrical resistivities and seismic P-wave velocities using appropriate petrophysical models. In the interpretation of our preferred model, a shallow ∼40 m thick freshwater sandy aquifer with 85–100 Ωm resistivity, 10–32 per cent interconnected porosity and <13 per cent clay content overlies a 105–115 m thick conductive sequence of clay and intercalated salt-water-saturated sands with 15–20 Ωm total resistivity, 1−27 per cent interconnected porosity and 15–60 per cent clay content. A third ∼60 m thick sandy layer with 40–50 Ωm resistivity, 10–33 per cent interconnected porosity and <15 per cent clay content is underlain by the basement with 3200–4000 Ωm total resistivity. According to an interpretation of helicopter TEM data that cover the entire Okavango Delta and borehole logs, the second and third layers may represent lacustrine sediments from Paleo Lake Makgadikgadi and a moderately resistive freshwater aquifer comprising sediments of the recently proposed Paleo Okavango Megafan, respectively." @default.
- W2095794777 created "2016-06-24" @default.
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- W2095794777 date "2015-07-07" @default.
- W2095794777 modified "2023-09-26" @default.
- W2095794777 title "Joint inversions of three types of electromagnetic data explicitly constrained by seismic observations: results from the central Okavango Delta, Botswana" @default.
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- W2095794777 cites W1971589935 @default.
- W2095794777 cites W1972599503 @default.
- W2095794777 cites W1983430531 @default.
- W2095794777 cites W1992319314 @default.
- W2095794777 cites W1992494577 @default.
- W2095794777 cites W1992837617 @default.
- W2095794777 cites W1998340352 @default.
- W2095794777 cites W1999187736 @default.
- W2095794777 cites W2000888817 @default.
- W2095794777 cites W2003971463 @default.
- W2095794777 cites W2006538469 @default.
- W2095794777 cites W2011757174 @default.
- W2095794777 cites W2015710205 @default.
- W2095794777 cites W2018570871 @default.
- W2095794777 cites W2020412784 @default.
- W2095794777 cites W2022124672 @default.
- W2095794777 cites W2023665858 @default.
- W2095794777 cites W2023966818 @default.
- W2095794777 cites W2025432749 @default.
- W2095794777 cites W2034389383 @default.
- W2095794777 cites W2041436028 @default.
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- W2095794777 cites W2058795006 @default.
- W2095794777 cites W2062897230 @default.
- W2095794777 cites W2070174151 @default.
- W2095794777 cites W2072197561 @default.
- W2095794777 cites W2073476053 @default.
- W2095794777 cites W2075486734 @default.
- W2095794777 cites W2076576252 @default.
- W2095794777 cites W2079098033 @default.
- W2095794777 cites W2085518058 @default.
- W2095794777 cites W2089823816 @default.
- W2095794777 cites W2092510104 @default.
- W2095794777 cites W2101813461 @default.
- W2095794777 cites W2108064160 @default.
- W2095794777 cites W2110015125 @default.
- W2095794777 cites W2110288593 @default.
- W2095794777 cites W2119191748 @default.
- W2095794777 cites W2119998244 @default.
- W2095794777 cites W2120438308 @default.
- W2095794777 cites W2120751848 @default.
- W2095794777 cites W2122498972 @default.
- W2095794777 cites W2126671837 @default.
- W2095794777 cites W2127059115 @default.
- W2095794777 cites W2130315788 @default.
- W2095794777 cites W2131903153 @default.
- W2095794777 cites W2133435058 @default.
- W2095794777 cites W2134862804 @default.
- W2095794777 cites W2136117544 @default.
- W2095794777 cites W2137331549 @default.
- W2095794777 cites W2139065094 @default.
- W2095794777 cites W2142427203 @default.
- W2095794777 cites W2142866815 @default.
- W2095794777 cites W2151074885 @default.
- W2095794777 cites W2155749856 @default.
- W2095794777 cites W2165296126 @default.
- W2095794777 cites W2166971496 @default.
- W2095794777 cites W2170747546 @default.
- W2095794777 cites W2171475701 @default.
- W2095794777 cites W2231735693 @default.
- W2095794777 cites W2480098077 @default.
- W2095794777 cites W2494897775 @default.
- W2095794777 cites W2497045146 @default.
- W2095794777 cites W2771418610 @default.
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- W2095794777 cites W4240429068 @default.
- W2095794777 cites W4256129314 @default.
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- W2095794777 doi "https://doi.org/10.1093/gji/ggv184" @default.
- W2095794777 hasPublicationYear "2015" @default.
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