Gravity, Magnetics, Heat Flow & Tectonics
New Magnetic Anomaly Map of the U.S. & North America (2009)
With Corrected Long-wavelengths for the Conterminous U.S.A.
Prepared at University of Kentucky
Potential fields (gravity, magnetics, heat flow) geophysics theory and its global/planetary, regional, geo-hazards, tectonic, environmental, and archeological applications.
Research interests of Professor Ravat, his students, and research associates range from global and planetary geophysics and tectonics, regional-scale geophysics to solving environmental, engineering, and archeological geophysical problems.
The U.S. National Science Foundation has funded us to decipher the structure and evolution of the central portion of the U.S. and understand better some enigmatic gravity and magnetic field features that may have represented the edges of the North American continent more than a billion years ago. This project has spawned several offshoots and discoveries: for example, developing techniques for estimating temperatures deep inside the crust, developing techniques for combined interpretation of gravity, magnetic, heat flow, and seismic data for understanding better the structure, composition, and evolution of the Earth's lithosphere, development of several gravity and magnetic fields edge detection techniques including the holy grail magnetic source edge detection, the Analytic Signal for 3D sources, and so on.
One graduate student, Melissa Ditty, working with magnetic field data from NASA's Mars Global Surveyor satellite, developed a new technique to estimate paleopole locations from the edges of magnetic sources on Mars. When tied with the ages of paleopoles, her estimates of Mars' paleopoles will constrain the models of how Mars changed it orientation in its ancient past.
Leah Newman, a graduate student in the laboratory, is focusing on the mysteries of intriguing magnetic features on the dark side of the Moon in the South Polar Aitken basin using data from Japan's SELENE (Kaguya) mission.
Rachel Durham, a graduate student in the laboratory, is working on magnetic signatures of subductions zones in order to decipher ancient slabs embedded in the lithosphere today.
One of the most exciting recent project we have been involved with is the preparation of the World Digital Magnetic Anomaly Map published in 2007 by UNESCO and CGMW and initiated by IAGA/IUGG. The data and maps are available at: http://ftp.gtk.fi/WDMAM2007/. WDMAM 2.0 was published in 2015 (http://www.wdmam.org). Interpretation of this map in the context of the geology and geophysics of the world and improvements to these data to facilitate the third edition of this map are underway.
In addition, we continue our efforts to improve magnetic anomaly data for the United States collected during the National Uranium Resource Evalutation (NURE) project during 1970s using new methodologies. Our long-wavelength corrected US magnetic database and report is presently available at http://pubs.usgs.gov/of/2009/1258/.
- NASA: Evaluation of world magnetic models, 2016-2017.
- NASA: Source Parameter Interpretation of High Resolution Lunar Magnetic Anomalies from SELENE (Kaguya) and Lunar Prospector Data, 2016-2020.
- NSF: Deciphering the Structure and Evolution of North America’s Cratonic Core, $155,000, 2013 to 2017.
- NSF: US-Egypt Joint Science & Technology Board/U.S. State Dept: Spectral analysis of aeromagnetic data for geothermal reconnaissance of the west of the Red Sea region in Egypt, $60,000, 2006 to 2011.
- U.S. Geological Survey: Magnetic Anomalies of the continental U.S. from NURE data using the Comprehensive Model, $50,000, 2006 to 2009.
- National Aeronautics and Space Administration (NASA): Geodynamics of the lithosphere using potential-field variations, $152,000, 2003 to 2007.
Learn more about Dr. Ravat
- office: 305A Slone Research Building (inside office)
- email: email@example.com