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Creator | Title | Description | Subject | Date |
| 1 |
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Zhdanov, Michael | 3D inversion of airborne electromagnetic data | Time-domain airborne surveys gather hundreds of thousands of multichannel, multicomponent samples. The volume of data and other complications have made 1D inversions and transforms the only viable method to interpret these data, in spite of their limitations. We have developed a practical methodolog... | | 2012-01-01 |
| 2 |
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Zhdanov, Michael S. | Novel approach to the model appraisal and resolution analysis of regularized geophysical inversion | The existing techniques for appraisal of geophysical inverse images are based on calculating the model resolution and the model covariance matrices. In some applications, however, it becomes desirable to evaluate the upper bounds of the variations in the solution of the inverse problem. It is possib... | Geophysical inversion; Electromagnetic modeling; Cauchy inequality; Resolution analysis; Lanczos decomposition method; SLDM; Voisey's Bay; 3-D modeling | 2006 |
| 3 |
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Zhdanov, Michael S. | Three-dimensional regularized focusing inversion of gravity gradient tensor component data | We develop a new method for interpretation of tensor gravity field component data, based on regularized focusing inversion. The focusing inversion makes its possible to reconstruct a sharper image of the geological target than conventional maximum smoothness inversion. This new technique can be eff... | Focusing inversion; Gravity gradient; Gravity gradiometry | 2004 |
| 4 |
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Zhdanov, Michael S. | Rigorous 3D inversion of marine CSEM data based on the integral equation method | Marine controlled-source electromagnetic (MCSEM) surveys have become an important part of offshore petroleum exploration. However, due to enormous computational difficulties with full 3D inversion, practical interpretation of MCSEM data is still a very challenging problem. We present a new approach ... | | 2007 |
| 5 |
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Chapman, David S. | Geothermics and climate change: 2. Joint analysis of borehole temperature and meteorological data | Long-period ground surface temperature variations contained in bore hole temperature-depth profiles form a complementary climate change record to high-frequency, but noisy surface air temperature (SAT) records at weather stations. We illustrate the benefits of jointly analyzing geothermal and meteo... | Surface air temperature; Ground surface temperature; Borehole temperatures; Geothermal observations; Heat transfer | 1998 |
| 6 |
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Zhdanov, Michael | Large-scale 3D inversion of marine magnetotelluric data: Case study from the Gemini prospect, Gulf of Mexico | Three-dimensional magnetotelluric (MT) inversion is an emerging technique for offshore hydrocarbon exploration. We have developed a new approach to the 3D inversion of MT data, based on the integral equation method. The Tikhonov regularization and physical constraint have been used to obtain a stab... | | 2011 |
| 7 |
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Zhdanov, Michael | Three-dimensional inversion of large-scale EarthScope magnetotelluric data based on the integral equation method: geoelectrical imaging of the Yellowstone conductive mantle plume | Interpretation of the EarthScope MT (magnetotelluric) data requires the development of a large-scale inversion method which can address two common problems of 3D MT inversion: computational time and memory requirements. We have developed an efficient method of 3D MT inversion based on an IE (integ... | | 2011 |
| 8 |
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Zhdanov, Michael S. | Localized S-inversion of time-domain electromagnetic data | Interpretation of time-domain electromagnetic (TDEM) data over inhomogeneous geological structures is a challenging problem of geophysical exploration. The most widely used approach of interpreting TDEM data is based on the smooth 1-D layered resistivity inversion. We have developed an effective t... | | 2002-01-01 |
| 9 |
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Fernandez, Diego P. | Formulation for the static permittivity of water and steam at temperatures from 238 K to 873 K at pressures up to 1200 MPa, including derivatives and Debye- Hückel coefficients | A new formulation is presented of the static relative permittivity or dielectric constant of water and steam, including supercooled and supercritical states. The range is from 238 K to 873 K, at pressures up to 1200 MPa. The formulation is based on the ITS-90 temperature scale. It correlates a selec... | Static relative permittivity; Dielectric constant | 1997 |
| 10 |
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Zhdanov, Michael | Two-dimensional magnetotelluric inversion of blocky geoelectrical structures | This paper demonstrates that there are alternative approaches to the magnetotelluric (MT) inverse problem solution based on different types of geoelectrical models. The traditional approach uses smooth models to describe the conductivity distribution in underground formations. In this paper, we pres... | | 2002-01-01 |
| 11 |
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Chapman, David S. | Inversion of bottom-hole temperature data: the Pineview field, Utah-Wyoming thrust belt | The present day temperature field in a sedimentary basin is a constraint on the maturation of hydrocarbons; this temperature field may be estimated by inverting corrected bottom-hole temperature (BHT) data. Thirty-two BHTs from the Pineview oil field are corrected for drilling disturbances by a Ho... | Thermal analysis; Bottom hole temperature; Inversion; Pineview Oil Field | 1988-05 |
| 12 |
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Zhdanov, Michael | Cross-well electromagnetic imaging in three dimensions | In this paper, we develop a new technique for 3D cross-well electromagnetic tomography, based on an EM borehole survey consisting of a moving vertical magnetic dipole transmitter, located in one or several boreholes, and a tri-axial induction receiver, located in the other boreholes. The method is b... | | 2003 |
| 13 |
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Zhdanov, Michael S. | Electromagnetic inversion using quasi-linear approximation | Three-dimensional electromagnetic inversion continues to be a challenging problem in electrical exploration. We have recently developed a new approach to the solution of this problem based on quasi-linear approximation of a forward modeling operator. It generates a linear equation with respect to ... | Quasi-linear approximation; Electromagnetic inversion | 2000 |
| 14 |
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Chapman, David S. | Geothermics and climate change: 1. Analysis of borehole temperatures with emphasis on resolving power | Temperature-depth data from six boreholes in western Utah and nine boreholes in southeastern Utah are reanalyzed for evidence of ground surface temperature (GST) histories. We invert the temperature-depth data using the functional space inverse algorithm of Shen and Beck [1991, 1992] which we prefer... | Surface air temperature; Ground surface temperature; Borehole temperatures; Geothermal observations; Geothermics | 1998 |
| 15 |
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Chapman, David S.; Harris, Robert N.; Allis, Richard George | Gravity signals at the Geysers geothermal system | Three high-precision gravity and GPS surveys have been conducted over The Geysers geothermal reservoir and surrounding area. These surveys, in September 2000, April 2001, and September 2001, provide an initial baseline for future imaging studies of spatial mass changes from the Santa Rosa Efflu... | Ground water change; Gravity surveys | 2002 |
| 16 |
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Zhdanov, Michael S. | 3-D magnetic inversion with data compression and image focusing | We develop a method of 3-D magnetic anomaly inversion based on traditional Tikhonov regularization theory. We use a minimum support stabilizing functional to generate a sharp, focused inverse image. An iterative inversion process is constructed in the space of weighted model parameters that acce... | | 2002-01-01 |
| 17 |
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Zhdanov, Michael S. | New approach to interpretation of airborne magnetic and electromagnetic data | We present a new technique for underground imaging based on the idea of space-frequency filtering and downward continuation of the observed airborne magnetic and electromagnetic data. The technique includes two major methods. The first method is related to the downward analytical continuation and ... | | 1996-01-01 |
| 18 |
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Jarrard, Richard D. | Velocity and density of carbonate-rich sediments from northeastern Australian margin: integration of core and log data | During Ocean Drilling Program (ODP) Leg 133, shipboard scientists obtained a remarkable quantity of both core and log measurements of the physical properties of carbonate-rich sediments. This suite of measurements provides a unique opportunity to evaluate the robustness of each measurement technique... | | 1993 |
| 19 |
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Zhdanov, Michael S. | Focusing geophysical inversion images | A critical problem in inversion of geophysical data is developing a stable inverse problem solution that can simultaneously resolve complicated geological structures. The traditional way to obtain a stable solution is based on maximum smoothness criteria. This approach, however, provides smoothe... | Focusing; Geophysical inversion images; Minimum gradient support functionals; MGS | 1999 |
| 20 |
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Chapman, David S.; Harris, Robert N. | Climate change in India inferred from geothermal observations | Temporal variations in surface ground temperature impart a signal to the subsurface thermal regime that is captured in borehole temperature-depth profiles. Seventy temperature-depth profiles in India, located between 12o and 28oN, are analyzed to infer past changes in ground temperature. | Climate change; Borehole temperatures; Surface ground temperature; Surface air temperature; Geothermal observations; India | 2002 |
| 21 |
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Chapman, David S.; Harris, Robert N. | Mid-Latitude (30°-60° N) climatic warming inferred by combining borehole temperatures with surface air temperatures | We construct a mid-latitude (30°-60° N) reduced temperature-depth profile from a global borehole temperature database compiled for climate reconstruction. This reduced temperature profile is interpreted in terms of past surface ground temperature change and indicates warming on the order of 1°C... | Surface air temperature; Surface ground temperature; Borehole temperatures; Geothermal observations | 2001 |
| 22 |
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Jarrard, Richard D. | Scientific methods: an online book | This book was originally intended as ˜How to do science™, or ˜How to be a scientist™, providing guidance for the new scientist, as well as some reminders and tips for experienced researchers. Such a book does not need to be written by the most expert or most famous scientist, but by one who... | Science; Process; Method | 2001 |
| 23 |
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Chapman, David S.; Picard, M. Dane | Heat flow in the Uinta Basin determined from bottom hole temperature (BHT) data | The thermal resistance (or Bullard) method is used to judge the utility of petroleum well bottom-hole temperature data in determining surface heat flow and subsurface temperature patterns in a sedimentary basin. Thermal resistance, defined as the quotient of a depth parameter AZ and thermal con... | Thermal analysis; Bottom hole temperature | 1984-04 |
| 24 |
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Brown, Francis Harold | Chronology | The boundaries of the Lower Omo Basin have been mapped by Fuchs (1939) and by Butzer (1970, 1971) in a general way. The structural features and physiography of the eastern and central part of the Lower Omo Basin are best expressed on the maps of Davidson et al. (1973). Walsh and Dodson (1969) have m... | | 1983 |
| 25 |
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Jarrard, Richard D. | Results of borehole televiewer observations in the Celebes and Sulu Seas | Borehole televiewer data were collected during Ocean Drilling Program Leg 124 to investigate stress orientations in the Sulu and Celebes sea basins. At Site 768C, in the Sulu Sea, televiewer logs were collected from 809-870 and 950-1250 meters below sea floor (mbsf). At Site 770C, in the Celebes Se... | | 1991 |
