South Lahontan

Reconstructing the Mediaeval low stands of Mono Lake, Sierra Nevada, California, USA

Holocene (Sage Journals) | December 1st, 2019

Palaeosimulations of Mono Lake covering the past 2 kyr have been conducted using a water balance model forced with tree-ring derived inflow estimates. The results show tw

Palaeosimulations of Mono Lake covering the past 2 kyr have been conducted using a water balance model forced with tree-ring derived inflow estimates. The results show two low stands, during the ninth to tenth and twelfth to thirteenth centuries, that agree well in timing and magnitude with those described by Stine (1987, 1990, 1994) on the basis of geomorphic evidence and relict trees and shrubs exposed on Mono Lake's artificially exposed shorelands. The lake simulation provides independent corroboration of the timing and magnitude of Stine's drought-induced low stands and supports the accuracy of tree-ring-derived estimates of Mediaeval precipitation and runoff reductions in the central Sierra Nevada. Specifically, we estimate that during the two Mediaeval droughts, centennial average precipitation and river runoff in the central Sierra Nevada reached as low as 75% of the twentieth century values, with multidecade averages as low as 60—65%. In both magnitude and duration, these droughts far exceed anything experienced in the region during modern times. An analysis of the spatial patterns of reconstructed drought indices shows that the particular `two drought' Mono Lake low stand signal was focused over central and southern California, indicating the dominant role of boreal winter precipitation deficits. In this respect, the `Great Sierra Nevada droughts' were somewhat distinct from the more general Great Basin/far western Plains pattern of Mediaeval aridity over the western USA.

Regional Ground-Water Evapotranspiration and Ground-Water Budgets, Great Basin, Nevada

U.S. Geological Survey (USGS) | July 1st, 2000

Regional water table (1994) and water-level changes in the Morongo Basin, San Bernardino County, California

U.S. Geological Survey (USGS) | July 1st, 1995

The Morongo Basin is in the Mojave Desert region of southern California, about 100 mi east of Los Angeles. Ground water is virtually the sole source of water in the Moro

The Morongo Basin is in the Mojave Desert region of southern California, about 100 mi east of Los Angeles. Ground water is virtually the sole source of water in the Morongo Basin. Increased pumping to meet the needs of an increasing resident population has resulted in ground-water overdraft in parts of the ground-water basin. Most of the water resources of the basin are managed by the Mojave Water Agency (MWA) and the U.S. Marine Corps Air/Ground Combat Center at Twentynine Palms (USMCAGCC). To help manage the ground-water resources, the MWA and the U.S. Marine Corps, Department of the Navy, requested the U.S. Geological Survey (USGS) to construct a regional water-table map of the Morongo ground-water basin. The purposes of this study were to construct a regional water-table map and determine areas of water-level change in the Morongo Basin. Existing data were evaluated and water levels were measured in selected wells throughout the Morongo Basin. Water-level measurements were used to construct a regional water-table map for 1994 conditions (fig. 1), and available historical water levels were used to construct hydrographs (shown in fig. 1) and determine water-level change at selected wells. Results of this study will aid the USGS in evaluating its current ground-water monitoring network in the Morongo Basin. In addition, information gained through this study will contribute to ongoing projects in the area, such as the Regional Aquifer-System Analysis (RASA) of Southern California.

Regional water table (1996) and water-level changes in the Mojave River, Morongo, and Fort Irwin ground-water basins, San Bernardino County

U.S. Geological Survey (USGS) | July 1st, 1997

Regional water table (1998) and ground-water-level changes in the Mojave River and the Morongo ground-water basins, San Bernardino County, California

U.S. Geological Survey (USGS) | July 1st, 2000

Regional Water Table (2000) and Ground-Water-Level Changes in the Mojave River and the Morongo Ground-Water Basins, Southwestern Mojave Desert, California

U.S. Geological Survey (USGS) | July 1st, 2003

Regional water table (2002) and water-level changes in the Mojave River and the Morongo ground-water basins, Southwestern Mojave Desert, California

U.S. Geological Survey (USGS) | July 1st, 2004

Regional Water Table (2004) and water-level changes in the Mojave River and Morongo ground-water basins, southwestern Mojave Desert, California

U.S. Geological Survey (USGS) | July 1st, 2004

Regional water table (2010) in the Mojave River and Morongo groundwater basins, Southwestern Mojave Desert, California

U.S. Geological Survey (USGS) | February 23rd, 2012

Data for static water-levels measured in about 610 wells during January through June 2010 by the U.S. Geological Survey (USGS), the Mojave Water Agency (MWA), and other l

Data for static water-levels measured in about 610 wells during January through June 2010 by the U.S. Geological Survey (USGS), the Mojave Water Agency (MWA), and other local water districts were compiled to construct a regional water-table map, which shows the altitude of the water table and general direction of groundwater movement in and around the Mojave River and Morongo groundwater basins. Water-level contours from the 2008 water-level map (Stamos and others, 2009) were used as a guide to interpret the 2010 water-level contours in areas where 2010 water-level data were not available. In addition to being available on the interactive map,the 2010 water-level data and contours are shown for the entire area of the Mojave River and Morongo groundwater basins on Plate 1 greater detail of the Warren subbasin in the Morongo groundwater basin is shown on Plate 2. Historical water-level data from the National Water Information System (NWIS) database were used in conjunction with data collected for this study to construct 37 water-level hydrographs to show both long-term (1930 - 2010) and short-term (1990 - 2010) water-level changes in the Mojave River and Morongo groundwater basins. Water-level changes between spring 2008 and spring 2010 were determined by comparing water levels measured in the same well during both periods. Water-level changes between the studies on this website can be displayed on the interactive map by entering the years of interest.

Regional Water Table (2012) in the Mojave River and Morongo Groundwater Basins, Southwestern Mojave Desert, California

U.S. Geological Survey (USGS) | December 31st, 2012

Data for static water-levels measured in about 580 wells during March-May 2012 by the U.S. Geological Survey (USGS), the Mojave Water Agency (MWA), and other local water

Data for static water-levels measured in about 580 wells during March-May 2012 by the U.S. Geological Survey (USGS), the Mojave Water Agency (MWA), and other local water districts were compiled to construct a regional water-table map. This map shows the elevation of the water table and general direction of groundwater movement in and around the Mojave River and Morongo groundwater basins. Water-level measurements recorded by the USGS and MWA staff were compiled according to the procedures described in the Groundwater Technical Procedures of the U.S. Geological Survey (Cunningham and Schalk, 2011). Water-level data submitted by cooperating local water districts were collected by using procedures established by the corresponding agency. All data were compared to historical data for quality-assurance purposes. Water-level contours from the 2010 water-level map (Smith and others, 2011) were used as a guide to interpret the 2012 water-level contours in areas where 2012 water-level data were not available. In addition to being available on the interactive map, 2012 water-level data and contours are shown for the entire area of the Mojave River and Morongo groundwater basins on plate 1; greater detail of the Warren subbasin in the Morongo groundwater basin is shown on plate 2. Water-level data for 2012 are accessible through the website by clicking on the 2012 button above the title on the Water Levels page. Historical water-level data from the National Water Information System (NWIS) database were used in conjunction with data collected for this study to construct 36 water-level hydrographs to show long-term (1930-2012) and short-term (1990-2012) water-level changes in the Mojave River and Morongo groundwater basins. Water-level changes between the spring of 2010 and spring of 2012 were determined by comparing water levels measured in the same well during both periods. Water-level changes between the studies on this website can also be displayed on the interactive map by selecting the years of interest from the Groundwater Data menu.