Andrew Y Morita
Science and Products
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
Evaluation of land subsidence and ground failures at Bicycle Basin, Fort Irwin National Training Center, California, 1992–2017
Groundwater has been pumped in the Bicycle Basin at Fort Irwin National Training Center since the 1960s, and the amount pumped has generally increased since the 1990s. After a large crack (approximately 0.5-kilometer long) formed at the surface of Bicycle Lake playa during 2005–06 in the area used as an aircraft runway, a...
Densmore, Jill; Ellett, Kevin M.; Sneed, Michelle; Brandt, Justin T.; Howle, James F.; Morita, Andrew Y.; Borela, Rodrigo; Bobet, Antonio; Thayer, Drew C.
Geochemistry of mercury and other constituents in subsurface sediment—Analyses from 2011 and 2012 coring campaigns, Cache Creek Settling Basin, Yolo County, California
Cache Creek Settling Basin was constructed in 1937 to trap sediment from Cache Creek before delivery to the Yolo Bypass, a flood conveyance for the Sacramento River system that is tributary to the Sacramento–San Joaquin Delta. Sediment management options being considered by stakeholders in the Cache Creek Settling Basin include sediment excavation...
Arias, Michelle R.; Alpers, Charles N.; Marvin-DiPasquale, Mark C.; Fuller, Christopher C.; Agee, Jennifer L.; Sneed, Michelle; Morita, Andrew Y.; Salas, Antonia
Geologic structure of the Yucaipa area inferred from gravity data, San Bernardino and Riverside Counties, California
In the spring of 2009, the U.S. Geological Survey, in cooperation with the San Bernardino Valley Municipal Water District, began working on a gravity survey in the Yucaipa area to explore the three-dimensional shape of the sedimentary fill (alluvial deposits) and the surface of the underlying crystalline basement rocks. As water use has increased...
Mendez, Gregory O.; Langenheim, Victoria E.; Morita, Andrew; Danskin, Wesley R.
Aquifer geometry, lithology, and water levels in the Anza–Terwilliger area—2013, Riverside and San Diego Counties, California
The population of the Anza–Terwilliger area relies solely on groundwater pumped from the alluvial deposits and surrounding bedrock formations for water supply. The size, characteristics, and current conditions of the aquifer system in the Anza–Terwilliger area are poorly understood, however. In response to these concerns, the U.S....
Landon, Matthew K.; Morita, Andrew Y.; Nawikas, Joseph M.; Christensen, Allen H.; Faunt, Claudia C.; Langenheim, Victoria E.
Water- and air-quality and surficial bed-sediment monitoring of the Sweetwater Reservoir watershed, San Diego County, California, 2003-09
In 1998, the U.S. Geological Survey, in cooperation with the Sweetwater Authority, began a study to assess the overall health of the Sweetwater watershed in San Diego County, California. This study was designed to provide a data set that could be used to evaluate potential effects from the construction and operation of State Route 125 within the...
Mendez, Gregory O.; Majewski, Michael S.; Foreman, William T.; Morita, Andrew Y.
Water- and air-quality monitoring of the Sweetwater Reservoir Watershed, San Diego County, California - Phase One results, continued, 2001-2003
In 1998, the U.S. Geological Survey, in cooperation with the Sweetwater Authority, began a study to monitor water, air, and sediment at the Sweetwater and Loveland Reservoirs in San Diego County, California. The study includes regular sampling of water and air at Sweetwater Reservoir for chemical constituents, including volatile organic compounds...
Mendez, Gregory O.; Foreman, William T.; Morita, Andrew; Majewski, Michael S. Anza-Terwilliger hydrogeologic structures in Riverside County, California
This digital geospatial dataset documents the fault traces in the Anza and Terwilliger area of southwest Riverside County, California, that were modified from Moyle (1971) by Woolfenden and Bright (1988, figure 8). The fault information is used to help assess ground-water level changes in the area of Anza and Terwilliger between 2004 and 2005.
Morita, Andrew; Clark, Dennis A.; Morita, Andrew Y.; Martin, Peter Anza-Terwilliger study wells in Riverside County, California
This digital data set contains the locations, water-level altitude, and water-level differences of 70 wells selected to document water-level changes between fall 2004 and spring 2005 in the Anza-Terwilliger area of Riverside County, California. The winter of 2005 was one of the wettest periods on record. Links to the U.S. Geological Survey...
Morita, Andrew; Clark, Dennis A.; Martin, Peter