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Gravity . Janice Kukuk Rob Ghigieri Ross Whitmore. http://sciencefun.wordpress.com/2008/04/. Takehome Message . Bolstered NE portion of the Truckee Meadows Basin (TMB) Gravity dataset Hidden Valley Sub-basin. Purpose . Learn how to use a Gravimeter Fill data gaps in TMB dataset
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Gravity Janice Kukuk Rob Ghigieri Ross Whitmore http://sciencefun.wordpress.com/2008/04/
Takehome Message • Bolstered NE portion of the Truckee Meadows Basin (TMB) Gravity dataset • Hidden Valley Sub-basin
Purpose • Learn how to use a Gravimeter • Fill data gaps in TMB dataset • Profile a smaller sub-basin in Hidden Valley
Methods • LaCost and Rhomberg Gravimeter • Grav2d • GM-SYS • Trimble GPS • Theodolite
Results for Prater Grav2d W E GM-SYS ~14 mGal anomaly Distance in km
Results for Hidden Valley Grav2d W E Tolerance 2 mGal Density contrast-0.33 g/cc GM-SYS -6 mGal Anomaly Distance in km
Comparison of results Prater W E (Modified from Widmer et al., 2007)
Error • Non-equilibrated spring • Terrain corrections • Elevation error • Inconsistent temperature • User error • Instrument drift
Future Work • Verification of Hidden Valley anomaly • Completion of D’Andreapkwy line to bolster dataset
TakehomeMessage • Bolstered NE portion of the Truckee Meadows Basin (TMB) Gravity dataset • Hidden Valley Sub-basin
References • Abbot, R.E., and Louie, J.N., 2000, Depth to bedrock using gravimetry in the Reno and Carson City, Nevada, Area basins: Geophysics, V. 65, p. 430-450. • Anderson, J., Su, F., Zeng, Y., 1999, Seismic Hazards in the vicinity of Las Vegas and Reno: Final Technical Report GS# 1434-HQ-97- GR-03044 (paper copy, 15 p.) • Telford, W.M., Geldhart, L.P., and Sheriff, R.E., 1990, Applied Geophysics: New York, Cambridge University Press, 770 p. • Widmer, M.C., Cashman, P.H., Benedict, F.C., Trexler, J.H., 2007, Neogene through Quaternary stratigraphy and structure in a portion of the Truckee Meadows Basin; a record of recent tectonic history: Geological Society of America Abstracts with programs, v. 39, no. 4 p.9