Science Explorer

Exploring: Gravitational Field (earth)

Gravitational potential as a source of earthquake energy

Modified 2012-03-12
https://pubs.er.usgs.gov/publication/70012003 (HTML Document 18.06 KB)

Abstract Some degree of tectonic stress within the earth originates from gravity acting upon density structures. The work performed by this "gravitational ... from the gravitational potential of the density structures into an elastic strain field prior to the event. An alternate theory involves partial ... tectonics stress" must have formerly existed as gravitational potential energy contained in the stress-causing density structure. According to the ... elastic rebound theory (Reid, 1910), the energy of earthquakes comes from an elastic strain field built up by fairly continuous elastic deformation in ...

11.12 – Tools and techniques: gravitational method

Modified 2015-12-08
https://pubs.er.usgs.gov/publication/70146890 (HTML Document 17.69 KB)

fundamental relations, densities of Earth materials, instruments, field procedures, data reduction, filtering, forward modeling, inversion, and field ... examples. The focus is on near-surface investigations as distinct from the solid Earth studies found elsewhere in this treatise. The gravitational method ... By: Abstract The gravitational method is used to investigate density variations within the subsurface at depths of several meters to tens of meters ...

Philip Brown II

https://www.usgs.gov/staff-profiles/philip-brown-ii (HTML Document 58.00 KB)

, phpMyAdmin, Flex, Joomla, ArcGIS, Oasis montaj, and Libre. ·         Earth Science related, object-oriented software development using C++, Visual Basic, Java ...

Philip Brown II

https://www.usgs.gov/node/719166 (HTML Document 58.00 KB)

, phpMyAdmin, Flex, Joomla, ArcGIS, Oasis montaj, and Libre. ·         Earth Science related, object-oriented software development using C++, Visual Basic, Java ...

The North American upper mantle: density, composition, and evolution

Modified 2013-03-14
https://pubs.er.usgs.gov/publication/70042015 (HTML Document 25.80 KB)

Journal of Geophysical Research B: Solid Earth By: Abstract The upper mantle of North America has been well studied using various seismic methods ... . Here we investigate the density structure of the North American (NA) upper mantle based on the integrative use of the gravity field and seismic data ... . The basis of our study is the removal of the gravitational effect of the crust to determine the mantle gravity anomalies. The effect of the crust is ... removed in three steps by subtracting the gravitational contributions of (1) topography and bathymetry, (2) low-density sedimentary accumulations, and (3 ...

The relationship between the instantaneous velocity field and the rate of moment release in the lithosphere

Modified 2017-01-24
https://pubs.er.usgs.gov/publication/70025436 (HTML Document 19.71 KB)

The relationship between the instantaneous velocity field and the rate of moment release in the lithosphere Geophysical Journal International ... for the case of lateral variations in gravitational potential energy, then velocity gradients can be produced only if the lithosphere has, on average ... , zero strength. The static force model may be related to the long-term velocity field but not the instantaneous velocity field (typically measured ... with a definite mean recurrence time, and that the Earth is well approximated as a linear elastic-viscoelastic coupled system, I derive a simple ...

geo-nsdi.er.usgs.gov_waf_open-file_01-503_metadata.xml

Modified 2016-12-05
https://data.usgs.gov/metadata/USGS_Geoscience_Data_Catalog/geo-nsdi.er.usgs.gov_waf_open-file_01-503_metadata.xml ( 13.49 KB)

geospatial datasets gravimeter measurement gravitational field (earth) magnetic field (earth) magnetometer ... geology 199710 200005 Field measurements made during this time period ... IGRF_NT IGRF reference field value 48949.40 48956.30 ...

Measurement of ground-water storage change and specific yield using the temporal-gravity method near Rillito Creek, Tucson, Arizona

Modified 2014-06-12
https://pubs.er.usgs.gov/publication/wri974125 (HTML Document 25.95 KB)

early December 1992 and early January 1994. The method applies Newton's Law of Gravitation to measure changes in the local gravitational field of the ... Earth that are caused by changes in the mass and volume of ground water. Gravity at 50 stations in a 6-square-mile area was measured repeatedly ...

Mineville, Eastern Adirondacks – Geophysical and Geologic Studies | USGS Mineral Resources Program

Modified 2017-01-24
https://minerals.usgs.gov/science/Mineville-geoscience-studies/index.html (HTML Document 26.57 KB)

Earth’s magnetic field or gravitational pull. When rocks with different magnetic properties are juxtaposed next to each other, such as an iron-rich ... Adirondacks in the late 1800s and early 1900s, but the area also contains deposits of rare earth minerals. These elements are used in mobile devices ... and mapping studies are used to determine how rare earth elements and other commodities are distributed within those rocks. Combining these results ... gabbro and a quartz sandstone, they generate subtle differences in Earth’s magnetic field that can be detected. In a similar manner, rocks with ...

Jeffrey Phillips

https://www.usgs.gov/staff-profiles/jeffrey-phillips (HTML Document 59.23 KB)

Denver, Colorado.  He develops and maintains the USGS potential-field geophysical software package for the PC, a public-domain resource for the ... geophysical community.   His research focuses on potential-field theory and its application to geologic problems, including water, mineral, and energy ... .  [Link] Phillips, J.D., 2016, Potential-field software, in Smith, K.S., Phillips, J.D., McCafferty, A.E., and Clark, R.N., eds., 2016, Developing ... Techniques: Gravitational Method, in Treatise on Geophysics (Second Edition), edited by Gerald Schubert, Elsevier, Oxford, 2015, Volume 11: Resources in the ...

Jeffrey Phillips

https://www.usgs.gov/node/720688 (HTML Document 59.23 KB)

Denver, Colorado.  He develops and maintains the USGS potential-field geophysical software package for the PC, a public-domain resource for the ... geophysical community.   His research focuses on potential-field theory and its application to geologic problems, including water, mineral, and energy ... .  [Link] Phillips, J.D., 2016, Potential-field software, in Smith, K.S., Phillips, J.D., McCafferty, A.E., and Clark, R.N., eds., 2016, Developing ... Techniques: Gravitational Method, in Treatise on Geophysics (Second Edition), edited by Gerald Schubert, Elsevier, Oxford, 2015, Volume 11: Resources in the ...

Benjamin Drenth

https://www.usgs.gov/staff-profiles/benjamin-drenth (HTML Document 78.18 KB)

, What lies beneath: Geophysical mapping of a concealed Precambrian intrusive complex along the Iowa-Minnesota border: Canadian Journal of Earth ... ., eds., New Mexico Geological Society Guidebook, 62nd Field Conference, Geology of the Tusas Mountains and Ojo Caliente, p. 165-176.  [Link] Grauch, V ...

Benjamin Drenth

https://www.usgs.gov/node/718908 (HTML Document 78.18 KB)

, What lies beneath: Geophysical mapping of a concealed Precambrian intrusive complex along the Iowa-Minnesota border: Canadian Journal of Earth ... ., eds., New Mexico Geological Society Guidebook, 62nd Field Conference, Geology of the Tusas Mountains and Ojo Caliente, p. 165-176.  [Link] Grauch, V ...

Land-subsidence and ground-water storage monitoring in the Tucson Active Management Area, Arizona

Modified 2014-05-28
https://pubs.er.usgs.gov/publication/fs08400 (HTML Document 22.66 KB)

. Gravity methods offer a means to directly measure ground-water overdraft through measurement of changes in the gravitational field of the Earth that are ...

Pacific Northwest Geologic Mapping and Urban Hazards - Geophysical Maps

Modified 2016-12-13
https://geomaps.wr.usgs.gov/pacnw/maps-geophysical.html (HTML Document 9.52 KB)

gravitational attraction of the earth is slightly less than normal. These gravity lows appear as circular blue regions on gravity maps, most notably the ... magnetic fields. Maps of the field variations are used to determine crustal structure at depth and to prospect for fault zones, basins, and deposits of ...

Benjamin Drenth

https://www.usgs.gov/staff-profiles/benjamin-drenth?qt-staff_profile_science_products=3 (HTML Document 78.18 KB)

, What lies beneath: Geophysical mapping of a concealed Precambrian intrusive complex along the Iowa-Minnesota border: Canadian Journal of Earth ... ., eds., New Mexico Geological Society Guidebook, 62nd Field Conference, Geology of the Tusas Mountains and Ojo Caliente, p. 165-176.  [Link] Grauch, V ...

geo-nsdi.er.usgs.gov_waf_open-file_2008_1299_metadata.xml

Modified 2016-12-05
https://data.usgs.gov/metadata/USGS_Geoscience_Data_Catalog/geo-nsdi.er.usgs.gov_waf_open-file_2008_1299_metadata.xml ( 8.01 KB)

Thesaurus geophysics geologic structure gravimeter measurement gravitational field (earth) geospatial datasets ...

geo-nsdi.er.usgs.gov_waf_open-file_2005_1444_metadata.xml

Modified 2016-12-05
https://data.usgs.gov/metadata/USGS_Geoscience_Data_Catalog/geo-nsdi.er.usgs.gov_waf_open-file_2005_1444_metadata.xml ( 14.18 KB)

gravimeter measurement gravitational field (earth) magnetic field (earth) maps and atlases geospatial datasets ... ). A regional isostatic field was calculated using an Airy-Heiskanen (Heiskanen and Vening Meinesz, 1958) model for local compensation of topographic ... contrast between the crust and mantle. This regional isostatic field was subtracted from the complete Bouguer anomaly, thus removing longwavelength ... variations in the gravity field that are inversely related to topography. The resulting isostatic residual gravity anomaly, therefore, is a reflection of ...

Anjana K Shah

https://www.usgs.gov/node/718942 (HTML Document 55.45 KB)

evaluation of rare-earth-element (REE) deposits. Concentrations of REE-bearing minerals in certain geological environments can be detected using ... ., and Lupulescu, M., 2016, Geophysical, geochemical, and geological approaches to evaluating rare earth resources in the Eastern Adirondacks, upstate ... . Daniels, A. Karst and R.B. Davis, 2015, Geophysical and geochemical approaches to evaluating placer rare earth element resources in the southeastern U.S ... J. Phillips, 2015, Aeromagnetic survey data used to map features of the Cook Inlet and Susitna basins, Alaska, AGU-SEG Workshop "Potential field and ...

Anjana K Shah

https://www.usgs.gov/staff-profiles/anjana-k-shah (HTML Document 55.45 KB)

evaluation of rare-earth-element (REE) deposits. Concentrations of REE-bearing minerals in certain geological environments can be detected using ... ., and Lupulescu, M., 2016, Geophysical, geochemical, and geological approaches to evaluating rare earth resources in the Eastern Adirondacks, upstate ... . Daniels, A. Karst and R.B. Davis, 2015, Geophysical and geochemical approaches to evaluating placer rare earth element resources in the southeastern U.S ... J. Phillips, 2015, Aeromagnetic survey data used to map features of the Cook Inlet and Susitna basins, Alaska, AGU-SEG Workshop "Potential field and ...