Geoff Cromwell
Science and Products
Evaluation of Groundwater Resources in the Adelaida Area of San Luis Obispo County, California
Stakeholders in San Luis Obispo County are concerned that the increased demand for water use has, and will continue to, affect groundwater levels and availability in the Adelaida area. To address stakeholder concerns, the County of San Luis Obispo Board of Supervisors has asked the USGS to conduct a comprehensive evaluation of groundwater resources of the Adelaida area.
San Antonio Creek Water Availability
Located in Santa Barbara County, California, the San Antonio Creek Groundwater Basin is a rural agricultural area that is reliant on local water supplies, predominantly groundwater. Because of the growth of irrigated agriculture in the area, water demands have increased significantly, taxing local groundwater supplies. Groundwater resources are also used to supply local inhabitants, as well as...
Yucaipa Subbasin Integrated Hydrologic Model
The USGS is developing a hydrologic model of the Yucaipa Subbasin to aid in evaluating and managing the groundwater resources in the area. The study results will provide a greater understanding of the geohydrology of the subbasin, and aid in the development of a groundwater-monitoring plan, as well as in the evaluation of potential hydrologic effects of future groundwater development and...
Depth to bedrock based on modeling of gravity data of the eastern part of Edwards Air Force Base, California
We describe a gravity survey acquired to determine the thickness of basin-fill deposits (depth to bedrock) and to delineate geologic structures that might influence groundwater flow beneath the eastern part of Edwards Air Force Base, California. Inversion of these gravity data combined with geologic map and well information provides an estimate of...
Langenheim, Victoria; Morita, Andrew; Christensen, Allen H.; Cromwell, Geoffrey; Ely, Christopher
Using a GIS to populate 3D geocellular geologic models
No abstract available
Sweetkind, Donald; Cromwell, Geoffrey Holocene paleointensity of the Island of Hawai'i from glassy volcanics
This study presents new high‐quality paleointensity records and 14C radiocarbon age determinations from the Island of Hawai `i during the Holocene. Previous studies on Hawai `i use experimental methods and statistical selection criteria that may produce inaccurate geomagnetic field strength estimates. Additional high‐quality paleointensity...
Cromwell, Geoffrey; Trusdell, Frank A.; Tauxe, Lisa; Staudigel, Hubert; Ron, Hagai
Santa Barbara and Foothill groundwater basins Geohydrology and optimal water resources management—Developed using density dependent solute transport and optimization models
Groundwater has been a part of the city of Santa Barbara’s water-supply portfolio since the 1800s; however, since the 1960s, the majority of the city’s water has come from local surface water, and the remainder has come from groundwater, State Water Project, recycled water, increased water conservation, and as needed, seawater desalination....
Nishikawa, Tracy; Paulinski, Scott R.; Nishikawa, Tracy; Cromwell, Geoffrey; Boyce, Scott E.; Stanko, Zachary P. Against the current— The Mojave River from sink to source: The 2018 Desert Symposium field trip road log
The Mojave River evolved over the past few million years by “fill and spill” from upper basins near its source in the Transverse Ranges to lower basins. Each newly “spilled into” basin in the series? sustained a long-lived lake but gradually filled with Mojave River sediment, leading to spill to a yet lower elevation? basin. The Mojave River...
Miller, David M.; Reynolds, R.E.; Groover, Krishangi D.; Buesch, David C.; Brown, H. J.; Cromwell, Geoffrey; Densmore, Jill; Garcia, A.L.; Hughson, D.; Knott, J.R.; Lovich, Jeffrey E. Water-resources and land-surface deformation evaluation studies at Fort Irwin National Training Center, Mojave Desert, California
The U.S. Army Fort Irwin National Training Center (NTC), in the Mojave Desert, obtains all of its potable water supply from three groundwater basins (Irwin, Langford, and Bicycle) within the NTC boundaries (fig. 1; California Department of Water Resources, 2003). Because of increasing water demands at the NTC, the U.S. Geological Survey (USGS), in...
Densmore, Jill; Dishart, Justine E.; Miller, David M.; Buesch, David C.; Ball, Lyndsay B.; Bedrosian, Paul A.; Woolfenden, Linda R.; Cromwell, Geoffrey; Burgess, Matthew K.; Nawikas, Joseph; O'Leary, David; Kjos, Adam; Sneed, Michelle; Brandt, Justin T.
The Ups and Downs of Groundwater Levels after the July 2019 Ridgecrest, CA Earthquakes
Effects from the two July 2019 Ridgecrest, CA earthquakes were observed in several USGS continuous groundwater-level monitoring sites in California, Nevada, and Arizona.