76 FR 80404 - Notice of Lodging of Consent Decree Under the Clean Air Act

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-23

.... 7661-7661f, and Title V's implementing federal and state regulations, at a portland cement manufacturing plant located near Mojave, California. The proposed Decree resolves the United States' claims...

78 FR 25758 - Amended Notice of Intent To Clarify the Scope of Analysis of the Environmental Document and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-02

... influence the scope of the environmental analysis, and guide the entire process from plan decision-making to... Amendment in the West Mojave Planning Area, to the Motorized Vehicle Access Element of the California Desert... focused scoping process to solicit public comments and identify issues related to the clarified scope of...

Region 9: California San Bernardino County Inadequate Letter (1/4/2000)

EPA Pesticide Factsheets

This November 23, 1999, letter from EPA notifies CARB that the documentation of the Moderate PM10 SIP submittal for the Mojave Desert planning area of San Bernadino county does not allow EPA to find it adequate for use in conformity analyses.

Region 9: California Los Angeles - San Bernadino Counties Adequate Letter Enclosure (5/20/2008)

EPA Pesticide Factsheets

This document is the enclosure to the April 16, 2008, letter from EPA provides adequacy finding for transportation conformity purposes the motor vehicle emissions budgets in the Antelope Valley-Western Mojave Desert 8-hour Ozone Early Progress Plan.

A Place in the Sun.

ERIC Educational Resources Information Center

Booth, Bibi; Brook, Richard; Rieben, Elizabeth; Wooster, Elizabeth

2001-01-01

Describes life in the Mojave Desert. Includes a map of the desert and a poster that can be used in the classroom with drawings and photographs of desert creatures. Presents three lesson plans on mapping deserts, earthshaking events, and weed invaders as well as a section of teacher resources. (SAH)

Mapping the surface characteristics of the Mojave with remote sensing for terrestrial habitat modeling

NASA Astrophysics Data System (ADS)

Nowicki, S. A.; Skuse, R. J.

2012-12-01

High-resolution ecological and climate modeling requires quantification of surface characteristics such as rock abundance, soil induration and surface roughness at fine-scale, since these features can affect the micro and macro habitat of a given area and ultimately determine the assemblage of plant and animal species that may occur there. Our objective is to develop quantitative data layers of thermophysical properties of the entire Mojave Desert Ecoregion for applications to habitat modeling being conducted by the USGS Western Ecological Research Center. These research efforts are focused on developing habitat models and a better physical understanding of the Mojave Desert, which have implications the development of solar and wind energy resources, military installation expansion and residential development planned for the Mojave. Thus there is a need to improve our understanding of the mechanical composition and thermal characteristics of natural and modified surfaces in the southwestern US at as high-resolution as possible. Since the Mojave is a sparsely-vegetated, arid landscape with little precipitation, remote sensing-based thermophysical analyses using Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER) day and nighttime imagery are ideal for determining the physical properties of the surface. New mosaicking techniques for thermal imagery acquired at different dates, seasons and temperatures have allowed for the highest-resolution mosaics yet generated at 100m/pixel for thermal infrared wavelengths. Among our contributions is the development of seamless day and night ASTER mosaics of land surface temperatures that are calibrated to Moderate Resolution Imaging Spectroradiometer (MODIS) coincident observations to produce both a seamless mosaic and quantitative temperatures across the region that varies spectrally and thermophysically over a large number of orbit tracks. Products derived from this dataset include surface rock abundance, apparent thermal inertia, and diurnal/seasonal thermal regime. Additionally, the combination of moderate and high-resolution thermal observations are used to map the spatial and temporal variation of significant rain storms that intermittently increase the surface moisture. The resulting thermally-derived layers are in the process of being combined with composition, vegetation and surface reflectance datasets to map the Mojave at the highest VNIR resolution (20m/pixel) and compared to currently-available lower-resolution datasets.

Spatially explicit decision support for selecting translocation areas for Mojave desert tortoises

USGS Publications Warehouse

Heaton, Jill S.; Nussear, Kenneth E.; Esque, Todd C.; Inman, Richard D.; Davenport, Frank; Leuteritz, Thomas E.; Medica, Philip A.; Strout, Nathan W.; Burgess, Paul A.; Benvenuti, Lisa

2008-01-01

Spatially explicit decision support systems are assuming an increasing role in natural resource and conservation management. In order for these systems to be successful, however, they must address real-world management problems with input from both the scientific and management communities. The National Training Center at Fort Irwin, California, has expanded its training area, encroaching U.S. Fish and Wildlife Service critical habitat set aside for the Mojave desert tortoise (Gopherus agassizii), a federally threatened species. Of all the mitigation measures proposed to offset expansion, the most challenging to implement was the selection of areas most feasible for tortoise translocation. We developed an objective, open, scientifically defensible spatially explicit decision support system to evaluate translocation potential within the Western Mojave Recovery Unit for tortoise populations under imminent threat from military expansion. Using up to a total of 10 biological, anthropogenic, and/or logistical criteria, seven alternative translocation scenarios were developed. The final translocation model was a consensus model between the seven scenarios. Within the final model, six potential translocation areas were identified.

Student Participation in Mars Sample Return Rover Field Tests, Silver Lake, California

NASA Technical Reports Server (NTRS)

Anderson, R. C.; Arvidson, R. E.; Bowman, J. D.; Dunham, C. D.; Backes, P.; Baumgartner, E. T.; Bell, J.; Dworetzky, S. C.; Klug, S.; Peck, N.

2000-01-01

An integrated team of students and teachers from four high schools across the country developed and implemented their own mission of exploration and discovery using the Mars Sample Return prototype rover, FIDO, at Silver Lake in the Mojave Desert.

76 FR 27344 - Water Resources Management Plan/Environmental Impact Statement, Mojave National Preserve, San...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-11

... within the Preserve to support cattle grazing operations and game populations. Human manipulation of... water for the same purposes. There also existed 133 small game wildlife water developments (also known as ``guzzlers'' or ``drinkers''), and 6 big game guzzlers, which intercept and store rainwater for...

HABITAT DISTRIBUTION MODELS FOR 37 VERTEBRATE SPECIES IN T HE MOJAVE DESERT ECOREGION OF NEVADA, ARIZONA, AND UTAH

EPA Science Inventory

Thirty-seven covered species in the Clark County Multi-Species Habitat Conservation Plan (MSHCP) were previously modeled through the Southwest Regional Gap Analysis Project (SWReGAP), using a deductive approach. To increase the applicability of such habitat models in the region ...

HABITAT DISTRIBUTION MODELS FOR 37 VERTEBRATE SPECIES IN THE MOJAVE DESERT ECOREGION OF NEVADA, ARIZONA, AND UTAH

EPA Science Inventory

Conservation planning for a species requires knowledge of the species’ population status and distribution. An important step in obtaining this information for many species is the development of models that predict the habitat distribution for the species. Such models can be usef...

Presentation--HABITAT DISTRIBUTION MODELS FOR 37 VERTEBRATE SPECIES IN THE MOJAVE DESERT ECOREGION OF NEVADA, ARIZONA, AND UTAH

EPA Science Inventory

Thirty-seven terrestrial vertebrate species in the Clark County Multi-Species Habitat Conservation Plan (MSHCP) were previously modeled through the Southwest Regional Gap Analysis Project (SWReGAP), using a deductive approach. To increase the applicability of such habitat models ...

Mojave Desert Ecosystem Program

Science.gov Websites

Toggle navigation logo garis Home About Search Contact About Us History The Mojave Desert Ecosystem providing dynamic, sustainable, land management decision-making at the ecosystem level. Its numerous mission of the Mojave Desert Ecosystem Program is to provide government agencies throughout the Mojave

Mapping habitat for multiple species in the Desert Southwest

USGS Publications Warehouse

Inman, Richard D.; Nussear, Kenneth E.; Esque, Todd C.; Vandergast, Amy G.; Hathaway, Stacie A.; Wood, Dustin A.; Barr, Kelly R.; Fisher, Robert N.

2014-01-01

Many utility scale renewable energy projects are currently proposed across the Mojave Ecoregion. Agencies that manage biological resources throughout this region need to understand the potential impacts of these renewable energy projects and their associated infrastructure (for example, transmission corridors, substations, access roads, etc.) on species movement, genetic exchange among populations, and species’ abilities to adapt to changing environmental conditions. Understanding these factors will help managers’ select appropriate project sites and possibly mitigate for anticipated effects of management activities. We used species distribution models to map habitat for 15 species across the Mojave Ecoregion to aid regional land-use management planning. Models were developed using a common 1 × 1 kilometer resolution with maximum entropy and generalized additive models. Occurrence data were compiled from multiple sources, including VertNet (http://vertnet.org/), HerpNET (http://www.herpnet.org), and MaNIS (http://manisnet.org), as well as from internal U.S. Geological Survey databases and other biologists. Background data included 20 environmental covariates representing terrain, vegetation, and climate covariates. This report summarizes these environmental covariates and species distribution models used to predict habitat for the 15 species across the Mojave Ecoregion.

77 FR 10555 - Notice of Public Meetings: Mojave-Southern Great Basin Resource Advisory Council, Nevada

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-22

... variety of planning and management issues associated with public land management in Nevada. Topics for... DEPARTMENT OF THE INTERIOR Bureau of Land Management [LLNVS00000 L12200000.PM0000 LXSS006F0000... Resource Advisory Council, Nevada AGENCY: Bureau of Land Management, Interior. ACTION: Notice of public...

Late Holocene Hydrologic Variability in the southeast Mojave Desert using sediments from Ford Lake, California

NASA Astrophysics Data System (ADS)

Leidelmeijer, J.; Kirby, M.; Anderson, W. T., Jr.; Mayer, S. A.; Palermo, J. A.; Stout, C.; Shellhorn, A.; Weisberg, G.; Rangel, H.; Hess, B.

2017-12-01

Most published lacustrine studies located in the Mojave Desert focus on lakes that receive the majority of their water from the Mojave River (e.g., Silver Lake, Cronese Lakes, Soda Lake, etc). Consequently, these Mojave River-fed lake sites record coastal hydroclimatic signals rather than a solely Mojave-only signal. The reason for this signal-disconnect is that the Mojave River is sourced in the San Bernardino Mountains, where annual precipitation is dictated by coastal hydroclimates. Therefore, much remains unknown about how the Mojave Desert changed during the Holocene at sub-millennial time scales. To address this problem and fill in an important geographical gap, we focus on Ford Lake in the southeastern Mojave Desert. Ford Lake is an internally drained, closed basin, and it is completely disconnected from the Mojave River. As a result, it represents one of the first lakes studied in the Mojave Desert with a climate signal that is 100% Mojave. Sediments from Ford Lake provide valuable context for understanding hydroclimatic variability exclusive to the Mojave Desert. To date, two hand-dug 1.5 m trenches (depocenter and littoral zone) and 3 overlapping sediments cores from the lake's depocenter have been sampled. The total core length is 3.55 m and bottomed in coarse alluvium, suggesting we captured the complete lacustrine sediment package. Initial results by Mayer (2016) focused on the most recent 1200 calendar years before present, or the upper 2.16 m. Mayer (2016) found evidence for increased run-off (wetter climate) during the Little Ice Age and reduced run-off (drier climate) during the Medieval Climatic Anomaly. Here, we complete the study, improving age control using sediment charcoal. Grain size, magnetic susceptibility, percent total organic matter, percent total carbonate content, C:N ratios and C and N isotopic analyses are (will be) measured at 1 cm contiguous intervals. The Ford Lake record has been (will be) compared to pre-existing regional records (i.e. Silver Lake, Abbott Lake, Crystal Lake, Zaca Lake, and the Santa Barbara Basin) to determine similarities and differences between coastal and Mojave-only climate. Final results will be compared to existing forcings to examine the cause of late Holocene hydroclimatic changes.

5. Photographic copy of engineering drawing showing plans, elevation and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. Photographic copy of engineering drawing showing plans, elevation and section of Deluge Water System, including reservior (4316), Pump House (4317), and water tower. Job No. Muroc A(5-ll), Military Construction, San Bernardino-Mojave Area, San Bernardino, California: Muroc Bombing Range, Muroc Lake, California.; Additional Facilities for Materiel Center Flight Test Base, Water Supply System, Plans and Sections, Sheet 5 of 10, May 1943. Records on file at AFFTC/CE-CECC-B (Design/Construction Flight/RPMC), Edwards AFB, California. - Edwards Air Force Base, North Base, Deluge Water Pumping Station, Near Second & D Streets, Boron, Kern County, CA

Ft. Mojave Smoke Shop Minor NSR Permit Application

EPA Pesticide Factsheets

Tribal Minor New Source Review (NSR) Permit application submitted by Environmental Technology Inc. for soil & groundwater remediation at the Ft. Mojave Smoke Shop, 8501 S. Highway 95 Mojave Valley, AZ 86440.

Mid-to-Late Holocene Hydrologic Variability in the Southeastern Mojave Desert Using Sediments from Ford Lake

NASA Astrophysics Data System (ADS)

Mayer, S. A.; Kirby, M. E.; Anderson, W. T., Jr.; Stout, C.; Palermo, J. A.

2015-12-01

The focal point of most lacustrine studies in the Mojave National Preserve (MNP) to date has been on lakes fed by the Mojave River. The source of the Mojave River is found on the northern flank of the San Bernardino Mountains. Consequently, the lakes that receive these waters are predominantly responding to the winter-only coastal southwest United States climate (e.g., Kirby et al., 2015 - Silver Lake); to a lesser degree, these lakes are also influenced by the Mojave's bimodal winter/summer climate. Ford Lake, located in the southeastern Mojave Desert is a small closed basin lake with its drainage basin located exclusively within the Mojave Desert. Therefore, sediment collected from Ford Lake contains a 100% Mojave-only climate signal. A 2.18 m sediment core was collected from the lake's depocenter in May 2015. Sediment analyses at 1 cm contiguous intervals include: magnetic susceptibility (MS), percent total organic matter, percent total carbonate content, and grain size analysis; C:N ratios, C and N isotope (δ13C and δ15N) analyses, and macrofossil counts are determined at 2 cm intervals. The site's age model is based on accelerator mass spectrometry (AMS) radiocarbon ages from discrete organic macrofossils or bulk organic carbon. To deconvolve the coastal climate, winter-only signal from the Mojave-only climate signal the data from Ford Lake will be compared to one Mojave River fed lake (Silver) and several southern California lakes (Lower Bear, Lake Elsinore, Dry Lake, and Zaca Lake). Our results will be analyzed in the context of climate forcings such as insolation and ocean - atmosphere dynamics.

Clustering of GPS velocities in the Mojave Block, southeastern California

USGS Publications Warehouse

Savage, James C.; Simpson, Robert W.

2013-01-01

We find subdivisions within the Mojave Block using cluster analysis to identify groupings in the velocities observed at GPS stations there. The clusters are represented on a fault map by symbols located at the positions of the GPS stations, each symbol representing the cluster to which the velocity of that GPS station belongs. Fault systems that separate the clusters are readily identified on such a map. The most significant representation as judged by the gap test involves 4 clusters within the Mojave Block. The fault systems bounding the clusters from east to west are 1) the faults defining the eastern boundary of the Northeast Mojave Domain extended southward to connect to the Hector Mine rupture, 2) the Calico-Paradise fault system, 3) the Landers-Blackwater fault system, and 4) the Helendale-Lockhart fault system. This division of the Mojave Block is very similar to that proposed by Meade and Hager. However, no cluster boundary coincides with the Garlock Fault, the northern boundary of the Mojave Block. Rather, the clusters appear to continue without interruption from the Mojave Block north into the southern Walker Lane Belt, similar to the continuity across the Garlock Fault of the shear zone along the Blackwater-Little Lake fault system observed by Peltzer et al. Mapped traces of individual faults in the Mojave Block terminate within the block and do not continue across the Garlock Fault [Dokka and Travis, ].

Identification and interpretation of tectonic features from Skylab imagery. [Mojave Desert block of Texas, Arizona, and Chihuahua, Mexico

NASA Technical Reports Server (NTRS)

Abdel-Gawad, M. (Principal Investigator)

1975-01-01

The author has identified the following significant results. Two alternate models for the extension of the Texas zone through the Mojave Desert block have been developed: (1) along the Pisgah Line, and (2) along the eastern Transverse Ranges; this model suggests a counterclockwise rotation of the Mojave block. Analysis of S190B photographs of the western Mojave Desert provides strong evidence for the feasibility of identifying recent fault breaks.

Regional water table (2000) and ground-water-level changes in the Mojave River and the Morongo ground-water basins, southwestern Mojave Desert, California

USGS Publications Warehouse

Smith, Gregory A.

2003-01-01

The Mojave River and Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water systems, and consequently, water availability. During 2000, the U. S. Geological Survey and other agencies made approximately 2,500 water-level measurements in the Mojave River and the Morongo ground-water basins. These data document recent conditions and, when compared with previous data, changes in ground-water levels. A water-level contour map was drawn using data from about 500 wells, providing coverage for most of the basins. Twenty-nine hydrographs show long-term (up to 70 years) water-level conditions throughout the basins, and 13 short-term (1996 to 2000) hydrographs show the effects of recharge and discharge along the Mojave River. In addition, a water-level-change map was compiled to compare 1998 and 2000 water-levels throughout the basins. In the Mojave River ground-water basins, water-level data showed little change from 1998 to 2000, with the exception of areas along the Mojave River. Water levels along the Mojave River were typically in decline or unchanged, with exceptions near the Hodge and the Lenwood outlet, where water levels rose in response to artificial recharge. The Morongo ground-water basin had virtually no change in water levels from 1998 to 2000, with the exception of Yucca Valley, where artificial recharge and ground-water withdrawal continues.

Threats to desert tortoise populations: a critical review of the literature

USGS Publications Warehouse

Boarman, William I.

2002-01-01

Decision in resource management are generally based on a combination of sociopolitical, economic, and environmental factors, and may be biased by personal values. These three components often contradict each other resulting in controversy. Controversies can usually be reduced when solid scientific evidence is used to support or refute a decision. However, it is important to recognize that data often do little to alter antagonists' positions when differences in values are the bases if the dispute. But, supporting data can make the decision more defensible, both legally and ethically, especially if the data supporting all opposing viewpoints are included in the decision-making process. Resource management decisions must be made using the best scientific information currently available. However, scientific data vary in two important measures of quality: reliability and validity. The reliability of the data is a measure of the degree to which the observations or conclusion can be repeated. Validity of the data is a measure of the degree to which the observation or conclusion reflects what actually occurs in nature. How the data are collected strongly affects the reliability of validity of ecological conclusions that can be made. Research data potentially relevant to management come from different sources, and the source often provides clues to the reliability and, to a certain extent, validity of data. Understanding the quality of data being used to make management decisions helps to separate the philosophical or value-based aspects of arguments from the objective ones, thus helping to clarify the decisions and judgments that need to be made. The West Mojave Plan is a multispecies, bioregional plan for the management of natural resources within a 9.4 million-acre area of the Mojave Desert in California. The plan addresses the legal requirements for the recovery of the desert tortoise (Gopherus agazzizii), a threatened species, but also covers an additional approximately 80 species of plants and animals assigned special status by the Bureau of Land Management, U. S. Fish and Wildlife Service, and California Department of Fish and Game. Within the planning area, 28 separate jurisdictions (counties, cities, towns, military installations, etc.) seek programmatic prescriptions that will facilitate streamlined environmental review, result in expedited authorization for development projects, and protect listed and unlisted species into the foreseeable future to avoid or minimize conflicts between proposed development and species' conservation and recovery. All of the scientific data available concerning the biology and management of these approximately 80 species and their habitats must be evaluated to develop a scientifically credible plan. This document provides an overview and evaluation of the knowledge of the major threats to the persistence and recovery of desert tortoise populations. I was specifically asked to evaluate the scientific veracity of the data and reports available. I summarize the data presently available with particular focus on the West Mojave Desert, evaluate the scientific integrity of the data. and identify major gaps in the available knowledge. I do not attempt to provide in-depth details on each study or threat; for more details I encourage the reader to consult the individual papers or reports city throughout this report (many of which are available at most university libraries and at the West Mojave Plan office in Riverside, California). I also do not attempt to characterize or evaluate the past or present management actions, except where they have direct bearing on evaluation of threats, nor do I attempt, for the most part, to acquire, generate, or evaluate new or existing, but uninterpreted data.

Clustering of GPS velocities in the Mojave Block, southeastern California

NASA Astrophysics Data System (ADS)

Savage, J. C.; Simpson, R. W.

2013-04-01

find subdivisions within the Mojave Block using cluster analysis to identify groupings in the velocities observed at GPS stations there. The clusters are represented on a fault map by symbols located at the positions of the GPS stations, each symbol representing the cluster to which the velocity of that GPS station belongs. Fault systems that separate the clusters are readily identified on such a map. The most significant representation as judged by the gap test involves 4 clusters within the Mojave Block. The fault systems bounding the clusters from east to west are 1) the faults defining the eastern boundary of the Northeast Mojave Domain extended southward to connect to the Hector Mine rupture, 2) the Calico-Paradise fault system, 3) the Landers-Blackwater fault system, and 4) the Helendale-Lockhart fault system. This division of the Mojave Block is very similar to that proposed by Meade and Hager []. However, no cluster boundary coincides with the Garlock Fault, the northern boundary of the Mojave Block. Rather, the clusters appear to continue without interruption from the Mojave Block north into the southern Walker Lane Belt, similar to the continuity across the Garlock Fault of the shear zone along the Blackwater-Little Lake fault system observed by Peltzer et al. []. Mapped traces of individual faults in the Mojave Block terminate within the block and do not continue across the Garlock Fault [Dokka and Travis, ].

78 FR 27256 - Meeting of the California Desert District Advisory Council

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-09

..., from 8 a.m. to 4:30 p.m. in Ridgecrest, Calif. at a location to be announced later. There also will be a DAC Business Meeting on Friday, June 7, from noon to 4:30 p.m. at the Jawbone Station Visitors... Saturday meeting will include a focus on the West Mojave Plan, as well as updates by council members, the...

Subsidence (2004-2009) in and near lakebeds of the Mojave River and Morongo groundwater basins, southwest Mojave Desert, California

USGS Publications Warehouse

Solt, Mike; Sneed, Michelle

2014-01-01

Subsidence, in the vicinity of dry lakebeds, within the Mojave River and Morongo groundwater basins of the southwest Mojave Desert has been measured by Interferometric Synthetic Aperture Radar (InSAR). The investigation has focused on determining the location, extent, and magnitude of changes in land-surface elevation. In addition, the relation of changes in land-surface elevation to changes in groundwater levels and lithology was explored. This report is the third in a series of reports investigating land-surface elevation changes in the Mojave and Morongo Groundwater Basins, California. The first report, U.S. Geological Survey (USGS) Water-Resources Investigations Report 03-4015 by Sneed and others (2003), describes historical subsidence and groundwater-level changes in the southwest Mojave Desert from 1969 to 1999. The second report, U.S. Geological Survey Water-Resources Investigations Report 07-5097, an online interactive report and map, by Sneed and Brandt (2007), describes subsidence and groundwater-level changes in the southwest Mojave Desert from 1999 to 2004. The purpose of this report is to document an updated assessment of subsidence in these lakebeds and selected neighboring areas from 2004 to 2009 as measured by InSAR methods. In addition, continuous Global Positioning System (GPS)(2005-10), groundwater level (1951-2010), and lithologic data, if available, were used to characterize compaction mechanisms in these areas. The USGS California Water Science Center’s interactive website for the Mojave River and Morongo groundwater basins was created to centralize information pertaining to land subsidence and water levels and to allow readers to access available data and related reports online. An interactive map of land subsidence and water levels in the Mojave River and Morongo groundwater basins displays InSAR interferograms, subsidence areas, subsidence contours, hydrographs, well information, and water-level contours. Background information, including a basic description of the mechanics of land subsidence and InSAR, as well as a description of the study area, is presented within the Mojave Water Resources Interactive Map and report.

76 FR 40722 - Mojave Solar LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-11

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER11-3917-000] Mojave Solar LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket Section 204 Authorization This is a supplemental notice in the above-referenced proceeding of Mojave Solar LLC...

Groundwater quality in the Mojave area, California

USGS Publications Warehouse

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Four groundwater basins along the Mojave River make up one of the study areas being evaluated. The Mojave study area is approximately 1,500 square miles (3,885 square kilometers) and includes four contiguous groundwater basins: Upper, Middle, and Lower Mojave River Groundwater Basins, and the El Mirage Valley (California Department of Water Resources, 2003). The Mojave study area has an arid climate, and is part of the Mojave Desert. Average annual rainfall is about 6 inches (15 centimeters). Land use in the study area is approximately 82 percent (%) natural (mostly shrubland), 4% agricultural, and 14% urban. The primary crops are pasture and hay. The largest urban areas are the cities of Victorville, Hesperia, and Apple Valley (2010 populations of 116,000, 90,000 and 69,000, respectively). Groundwater in these basins is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in the Mojave study area are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in the Mojave study area are completed to depths between 200 and 600 feet (18 to 61 meters), consist of solid casing from the land surface to a depth of 130 to 420 feet (40 to 128 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the mountains to the south, mostly through the Mojave River channel. The primary sources of discharge are pumping wells and evapotranspiration.

The binding effectiveness of anti-r-disintegrin polyclonal antibodies against disintegrins and PII and PIII metalloproteases: An immunological survey of type A, B and A + B venoms from Mohave rattlesnakes

PubMed Central

Cantú, Esteban; Mallela, Sahiti; Nyguen, Matthew; Báez, Raúl; Parra, Victoria; Johnson, Rachel; Wilson, Kyle; Suntravat, Montamas; Lucena, Sara; Rodríguez-Acosta, Alexis; Sánchez, Elda E.

2016-01-01

Snake venoms are known to have different venom compositions and toxicity, but differences can also be found within populations of the same species contributing to the complexity of treatment of envenomated victims. One of the first well-documented intraspecies venom variations comes from the Mohave rattlesnake (Crotalus scutulatus scutulatus). Initially, three types of venoms were described; type A venom is the most toxic as a result of ~45% Mojave toxin in the venom composition, type B lacks the Mojave toxin but contains over 50% of snake venom metalloproteases (SVMPs). Also, type A + B venom contains a combination of Mojave toxin and SVMP. The use of an anti-disintegrin antibody in a simple Enzyme-Linked Immunosorbent Assay (ELISA) can be used to identify the difference between the venoms of the type A, B, and A+B Mohave rattlesnakes. This study implements the use of an anti-recombinant disintegrin polyclonal antibody (ARDPA) for the detection of disintegrins and ADAMs (a disintegrin and metalloproteases) in individual crude snake venoms of Mohave rattlesnakes (Crotalus scutulatus scutulatus) of varying geographical locations. After correlation with Western blots, coagulation activity and LD50 data, it was determined that the antibody allows for a quick and cost-efficient identification of venom types. PMID:27989783

The Mojave River from sink to source: The 2018 Desert Symposium Field Trip Road Log

USGS Publications Warehouse

Miller, David; Reynolds, R.E.; Groover, Krishangi D.; Buesch, David C.; Brown, H. J.; Cromwell, Geoffrey; Densmore-Judy, Jill; Garcia, A.L.; Hughson, D.; Knott, J.R.; Lovich, Jeffrey E.

2018-01-01

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 currently terminates at Silver Lake, near Baker, CA, but previously overflowed this terminus onward to Lake Manly in Death Valley during the last glacial cycle. The river’s origin and evolution are intricately interwoven with tectonic, climatic, and geomorphic processes through time, beginning with San Andreas fault interactions that created a mountain range across a former externally draining river. We will see and discuss the Mojave River’s predecessor streams and basins, its evolution as it lengthened to reach the central Mojave Desert, local and regional tectonic controls, groundwater flow, flood history, and support of isolated perennial stream reaches that host endemic species. In association with these subjects are supporting studies such as paleoclimate records, location and timing for groundwater and wetlands in the central Mojave Desert, and effects of modern water usage. The trip introduces new findings for the groundwater basin of Hinkley Valley, including an ongoing remediation project that provides a wealth of information on past and present river flow and associated development of the groundwater system.

Adaptive responses reveal contemporary and future ecotypes in a desert shrub

USGS Publications Warehouse

Richardson, Bryce A.; Kitchen, Stanley G.; Pendleton, Rosemary L.; Pendleton, Burton K.; Germino, Matthew J.; Rehfeldt, Gerald E.; Meyer, Susan E.

2014-01-01

Interacting threats to ecosystem function, including climate change, wildfire, and invasive species necessitate native plant restoration in desert ecosystems. However, native plant restoration efforts often remain unguided by ecological genetic information. Given that many ecosystems are in flux from climate change, restoration plans need to account for both contemporary and future climates when choosing seed sources. In this study we analyze vegetative responses, including mortality, growth, and carbon isotope ratios in two blackbrush (Coleogyne ramosissima) common gardens that included 26 populations from a range-wide collection. This shrub occupies ecotones between the warm and cold deserts of Mojave and Colorado Plateau ecoregions in western North America. The variation observed in the vegetative responses of blackbrush populations was principally explained by grouping populations by ecoregions and by regression with site-specific climate variables. Aridity weighted by winter minimum temperatures best explained vegetative responses; Colorado Plateau sites were usually colder and drier than Mojave sites. The relationship between climate and vegetative response was mapped within the boundaries of the species–climate space projected for the contemporary climate and for the decade surrounding 2060. The mapped ecological genetic pattern showed that genetic variation could be classified into cool-adapted and warm-adapted ecotypes, with populations often separated by steep clines. These transitions are predicted to occur in both the Mojave Desert and Colorado Plateau ecoregions. While under contemporary conditions the warm-adapted ecotype occupies the majority of climate space, climate projections predict that the cool-adapted ecotype could prevail as the dominant ecotype as the climate space of blackbrush expands into higher elevations and latitudes. This study provides the framework for delineating climate change-responsive seed transfer guidelines, which are needed to inform restoration and management planning. We propose four transfer zones in blackbrush that correspond to areas currently dominated by cool-adapted and warm-adapted ecotypes in each of the two ecoregions.

Adaptive responses reveal contemporary and future ecotypes in a desert shrub.

PubMed

Richardson, Bryce A; Kitchen, Stanley G; Pendleton, Rosemary L; Pendleton, Burton K; Germino, Matthew J; Rehfeldt, Gerald E; Meyer, Susan E

2014-03-01

Interacting threats to ecosystem function, including climate change, wildfire, and invasive species necessitate native plant restoration in desert ecosystems. However, native plant restoration efforts often remain unguided by ecological genetic information. Given that many ecosystems are in flux from climate change, restoration plans need to account for both contemporary and future climates when choosing seed sources. In this study we analyze vegetative responses, including mortality, growth, and carbon isotope ratios in two blackbrush (Coleogyne ramosissima) common gardens that included 26 populations from a range-wide collection. This shrub occupies ecotones between the warm and cold deserts of Mojave and Colorado Plateau ecoregions in western North America. The variation observed in the vegetative responses of blackbrush populations was principally explained by grouping populations by ecoregions and by regression with site-specific climate variables. Aridity weighted by winter minimum temperatures best explained vegetative responses; Colorado Plateau sites were usually colder and drier than Mojave sites. The relationship between climate and vegetative response was mapped within the boundaries of the species-climate space projected for the contemporary climate and for the decade surrounding 2060. The mapped ecological genetic pattern showed that genetic variation could be classified into cool-adapted and warm-adapted ecotypes, with populations often separated by steep dines. These transitions are predicted to occur in both the Mojave Desert and Colorado Plateau ecoregions. While under contemporary conditions the warm-adapted ecotype occupies the majority of climate space, climate projections predict that the cool-adapted ecotype could prevail as the dominant ecotype as the climate space of blackbrush expands into higher elevations and latitudes. This study provides the framework for delineating climate change-responsive seed transfer guidelines, which are needed to inform restoration and management planning. We propose four transfer zones in blackbrush that correspond to areas currently dominated by cool-adapted and warm-adapted ecotypes in each of the two ecoregions.

Geohydrology and water quality of Marine Corps Logistics Base, Nebo and Yermo annexes, near Barstow, California

USGS Publications Warehouse

Densmore, Jill N.; Cox, Brett F.; Crawford, Steven M.

1997-01-01

Because ground water is the only dependable source of water in the Barstow area, a thorough understanding of the relationship between the geology and hydrology of this area is needed to make informed ground-water management andremediation decisions. This report summarizes geologic and hydrologic studies done during 1992-95 at the Marine Corps Logistics Base, Nebo and Yermo Annexes, near Barstow, California. The geologic investigation dealt with the stratigraphy and geologic history of the area and determined the location of faults that cross the Marine Corps Logistics Base, Nebo Annex. Two of these faultscoincide with significant ground-water barriers. Geologic and hydrologic data collected for this study were used to define two main aquifer systems in this area. The Mojave River aquifer is contained within the sand and gravel of the Mojave River alluvium, and the regional aquifer lies in the bordering alluvial-fan deposits and older alluvium. Water-level data showed that recharge occurs exten sively in the Mojave River aquifer but occurs only in small areas of the regional aquifer. Dissolved- solids concentrations showed that ground-water degradation exists in the Mojave River aquifer near the Nebo Annex and extends at least 1 mile downgradient of the Nebo golf course in the younger Mojave River alluvium. Nitrogen concentrations show that more than one source is causing the observed degradation in the Mojave River aquifer. Oxygen-18, deuterium, tritium, andcarbon-14 data indicate that the Mojave River and regional aquifers have different sources of recharge and that recent recharge occurs in the Mojave River aquifer but is more limited in the regional aquifer.

North-South contraction of the mojave block and strike-slip tectonics in southern california.

PubMed

Bartley, J M; Glazner, A F; Schermer, E R

1990-06-15

The Mojave block of southern California has undergone significant late Cenozoic north-south contraction. This previously unappreciated deformation may account for part of the discrepancy between neotectonic and plate-tectonic estimates of Pacific-North American plate motion, and for part of the Big Bend in the San Andreas fault. In the eastern Mojave block, contraction is superimposed on early Miocene crustal extension. In the western Mojave block, contractional folds and reverse faults have been mistaken for extensional structures. The three-dimensional complexity of the contractional structures may mean that rigid-block tectonic models of the region based primarily on paleomagnetic data are unreliable.

Against the current— The Mojave River from sink to source: The 2018 Desert Symposium field trip road log

USGS Publications Warehouse

Miller, David; Reynolds, R.E.; Groover, Krishangi D.; Buesch, David C.; Brown, H. J.; Cromwell, Geoffrey; Densmore-Judy, Jill; Garcia, A.L.; Hughson, D.; Knott, J.R.; Lovich, Jeffrey E.

2018-01-01

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 currently terminates at Silver Lake, near Baker, CA, but previously overflowed this terminus onward to Lake Manly in Death Valley during the last glacial cycle. The river’s origin and evolution are intricately interwoven with tectonic, climatic, and geomorphic processes through time, beginning with San Andreas fault interactions that created a mountain range across a former externally draining river. We will see and discuss the Mojave River’s predecessor streams and basins, its evolution as it lengthened to reach the central Mojave Desert, local and regional tectonic controls, groundwater flow, flood history, and support of isolated perennial stream reaches that host endemic species. In association with these subjects are supporting studies such as paleoclimate records, location and timing for groundwater and wetlands in the central Mojave Desert, and effects of modern water usage. The trip introduces new findings for the groundwater basin of Hinkley Valley, including an ongoing remediation project that provides a wealth of information on past and present river flow and associated development of the groundwater system.

Evaluation of volatile organic compounds in two Mojave Desert basins-Mojave River and Antelope Valley-in San Bernardino, Los Angeles, and Kern Counties, California, June-October 2002

USGS Publications Warehouse

Densmore, Jill N.; Belitz, Kenneth; Wright, Michael T.; Dawson, Barbara J.; Johnson, Tyler D.

2005-01-01

The California Aquifer Susceptibility Assessment of the Ground-Water Ambient Monitoring and Assessment Program was developed to assess water quality and susceptibility of ground-water resources to contamination from surficial sources. This study focuses on the Mojave River and the Antelope Valley ground-water basins in southern California. Volatile organic compound (VOC) data were evaluated in conjunction with tritium data to determine a potential correlation with aquifer type, depth to top of perforations, and land use to VOC distribution and occurrence in the Mojave River and the Antelope Valley Basins. Detection frequencies for VOCs were compiled and compared to assess the distribution in each area. Explanatory variables were evaluated by comparing detection frequencies for VOCs and tritium and the number of compounds detected. Thirty-three wells were sampled in the Mojave River Basin (9 in the floodplain aquifer, 15 in the regional aquifer, and 9 in the sewered subset of the regional aquifer). Thirty-two wells were sampled in the Antelope Valley Basin. Quality-control samples also were collected to identify, quantify, and document bias and variability in the data. Results show that VOCs generally were detected slightly more often in the Antelope Valley Basin samples than in the Mojave River Basin samples. VOCs were detected more frequently in the floodplain aquifer than in the regional aquifer and the sewered subset. Tritium was detected more frequently in the Mojave River Basin samples than in the Antelope Valley Basin samples, and it was detected more frequently in the floodplain aquifer than in the regional aquifer and the sewered subset. Most of the samples collected in both basins for this study contained old water (water recharged prior to 1952). In general, in these desert basins, tritium need not be present for VOCs to be present. When VOCs were detected, young water (water recharge after 1952) was slightly more likely to be contaminated than old water. Trihalomethanes (THMs) were detected less frequently in the Mojave River Basin samples than in the Antelope Valley Basin samples. The THMs that were detected in the Mojave River Basin were detected more frequently in the floodplain aquifer than in the regional aquifer and sewered subset. Solvents were detected more frequently in the Mojave River samples than in the Antelope Valley samples. In the Mojave River Basin samples, solvents were detected less frequently in the floodplain aquifer than in the regional aquifer and the sewered subset. Benzene, toluene, ethylbenzene and xylene (BTEX) were not detected in either study area. Methyl tert-butyl ether (MTBE) was detected in one sample from both the Mojave River and Antelope Valley Basins. The most frequently detected compound (detected in more than 10 percent of the wells) in the Mojave River Basin was chloroform. The two most frequently detected compounds in the Antelope Valley Basin were chloroform and tetrachloroethylene (PCE). In the Mojave River Basin, aquifer type and land use within 1,640 ft (500 m) of the well head were not statistically correlated with the number of VOCs detected, although VOCs were detected more frequently in the floodplain aquifer than in the regional aquifer and the sewered subset. Depth to the top of the perforations was an explanatory factor for the number of VOCs detected in the Mojave River Basin; the detection frequency was greater for shallow wells than for deep wells. In the Antelope Valley Basin, neither aquifer type, depth to the top of the perforations, nor land use within 1,640 ft of the well head were explanatory factors for the number of VOCs detected. Although aquifer type and depth to top of the perforations did explain the presence of tritium in the Mojave River Basin, land use within 1,640 ft of the well head was not a statistically significant explanatory factor for the presence of tritium in this basin. Aquifer type, depth to the top of the perfora

VizieR Online Data Catalog: MOJAVE. VIII. Faraday rotation in AGN jets. (Hovatta+, 2012)

NASA Astrophysics Data System (ADS)

Hovatta, T.; Lister, M. L.; Aller, M. F.; Aller, H. D.; Homan, D. C.; Kovalev, Yu. Y.; Pushkarev, A. B.; Savolainen, T.

2013-10-01

Our sample consists of 191 AGNs observed within the MOJAVE Very Long Baseline Array (VLBA) survey (Lister et al., 2009, cat. J/AJ/137/3718, Paper V). It includes 134 sources of the complete flux density-limited MOJAVE-1 sample. The rest of the sources belong to the MOJAVE-2 sample (http://www.physics.purdue.edu/astro/MOJAVE/allsources.html), which includes sources from the 2cm survey (Kellermann et al. 2004, cat. J/ApJ/609/539), gamma-ray blazars, and other sources with unusual jet properties. The sources were observed with VLBA in 2006 over 12 epochs with about monthly separation, each epoch containing 18 sources (except for epoch 2006 February 12, which included only 14 sources and epoch 2006 April 28, which included 17 sources). The observations were made in dual polarization mode using frequencies centered at 8.104, 8.424 (X band), 12.119, and 15.369GHz (U band). (2 data files).

Geochronology and paleoenvironment of pluvial Harper Lake, Mojave Desert, California, USA

USGS Publications Warehouse

Garcia, Anna L.; Knott, Jeffrey R.; Mahan, Shannon; Bright, Jordan

2014-01-01

Accurate reconstruction of the paleo-Mojave River and pluvial lake (Harper, Manix, Cronese, and Mojave) system of southern California is critical to understanding paleoclimate and the North American polar jet stream position over the last 500 ka. Previous studies inferred a polar jet stream south of 35°N at 18 ka and at ~ 40°N at 17–14 ka. Highstand sediments of Harper Lake, the upstream-most pluvial lake along the Mojave River, have yielded uncalibrated radiocarbon ages ranging from 24,000 to > 30,000 14C yr BP. Based on geologic mapping, radiocarbon and optically stimulated luminescence dating, we infer a ~ 45–40 ka age for the Harper Lake highstand sediments. Combining the Harper Lake highstand with other Great Basin pluvial lake/spring and marine climate records, we infer that the North American polar jet stream was south of 35°N about 45–40 ka, but shifted to 40°N by ~ 35 ka. Ostracodes (Limnocythere ceriotuberosa) from Harper Lake highstand sediments are consistent with an alkaline lake environment that received seasonal inflow from the Mojave River, thus confirming the lake was fed by the Mojave River. The ~ 45–40 ka highstand at Harper Lake coincides with a shallowing interval at downstream Lake Manix.

Paleoproterozoic mojaveprovince in northwestern Mexico? Isotopic and U-Pb zircon geochronologic studies of precambrian and Cambrian crystalline and sedimentary rocks, Caborca, Sonora

USGS Publications Warehouse

Lang, Farmer G.; Bowring, S.A.; Matzel, J.; Maldonado, G.E.; Fedo, C.; Wooden, J.

2005-01-01

Whole-rock Nd isotopic data and U-Pb zircon geochronology from Precambrian crystalline rocks in the Caborca area, northern Sonora, reveal that these rocks are most likely a segment of the Paleoproterozoic Mojave province. Supporting this conclusion are the observations that paragneiss from the ??? 1.75 Ga Bamori Complex has a 2.4 Ga Nd model age and contains detrital zircons ranging in age from Paleo- proterozoic (1.75 Ga) to Archean (3.2 Ga). Paragneisses with similar age and isotopic characteristics occur in the Mojave province in southern California. In addition, "A-type" granite exposed at the southern end of Cerro Rajon has ca 2.0 Ga Nd model age and a U-Pb zircon age of 1.71 Ga, which are similar to those of Paleoproterozoic granites in the Mojave province. Unlike the U.S. Mojave province, the Caborcan crust contains ca. 1.1 Ga granite (Aibo Granite), which our new Nd isotopic data suggest is largely the product of anatexis of the local Precambrian basement. Detrital zircons from Neoproterozoic to early Cambrian miogeoclinal arenites at Caborca show dominant populations ca. 1.7 Ga, ca. 1.4 Ga, and ca. 1.1 Ga, with subordinate Early Cambrian and Archean zircons. These zircons were likely derived predominately from North American crust to the east and northeast, and not from the underlying Caborcan basement. The general age and isotopic similarities between Mojave province basement and overlying miogeoclinal sedimentary rocks in Sonora and southern California is necessary, but not sufficient, proof of the hypothesis that Sonoran crust is allochthonous and was transported to its current position during the Mesozoic along the proposed Mojave-Sonora megashear. One viable alternative model is that the Caborcan Precambrian crust is an isolated, autochthonous segment of Mojave province crust that shares a similar, but not identical, Proterozoic geological history with Mojave province crust found in the southwest United States ?? 2005 Geological Society of America.

Source, movement and age of groundwater in the upper part of the Mojave River Basin, California, USA

USGS Publications Warehouse

Izbicki, J.A.; Martin, P.; Michel, R.L.

1995-01-01

Water samples from wells were collected and analysed for oxygen-18, deuterium, tritium, carbon-14, and carbon-13 to determine the source, movement and age of groundwater in the upper part of the Mojave River basin. Water in the alluvial aquifer has a median deuterium composition of -66??? and contains tritium, and was recently recharged by water from the Mojave River. Water in the regional aquifer near the Mojave River, near Summit Valley, and underlying several small washes has deuterium compositions heavier than -60???. Although some water in the regional aquifer near the Mojave River contains tritium, most of this water does not contain tritium. Carbon-14 data indicate that this water was recharged less than 2400 years ago. Water in the remainder of the regional aquifer has a median deuterium composition of -84???, which is as much as 20??? lighter than the volume-weighted deuterium composition of present-day precipitation. These data show that this water was recharged under climatic conditions different from average conditions today. Carbon-14 data indicate that some water in the regional aquifer was recharged more than 20 000 years ago.Water samples from wells were collected and analyzed for oxygen-18, deuterium, tritium, carbon-14, and carbon-13 to determine the source, movement and age of groundwater in the upper part of the Mojave River basin. Water in the alluvial aquifer has a median deuterium composition of -66qq and contains tritium, and was recently recharged by water from the Mojave River. Water in the regional aquifer near the Mojave River, near Summit Valley, and underlying several small washes has deuterium compositions heavier than -60qq. Although some water in the regional aquifer near the Mojave River contains tritium, most of this water does not contain tritium. Carbon-14 data indicate that this water was recharged less than 2400 years ago. Water in the remainder of the regional aquifer has a median deuterium composition of -84qq, which is as much as 20qq lighter than the volume-weighted deuterium composition of present-day precipitation. These data show that this water was recharged under climatic conditions different from average conditions today. Carbon-14 data indicate that some water in the regional aquifer was recharged more than 20 000 years ago.

Biological and Proteolytic Variation in the Venom of Crotalus scutulatus scutulatus from Mexico.

PubMed

Borja, Miguel; Neri-Castro, Edgar; Castañeda-Gaytán, Gamaliel; Strickland, Jason L; Parkinson, Christopher L; Castañeda-Gaytán, Juan; Ponce-López, Roberto; Lomonte, Bruno; Olvera-Rodríguez, Alejandro; Alagón, Alejandro; Pérez-Morales, Rebeca

2018-01-08

Rattlesnake venoms may be classified according to the presence/absence and relative abundance of the neurotoxic phospholipases A 2 s (PLA 2 s), such as Mojave toxin, and snake venom metalloproteinases (SVMPs). In Mexico, studies to determine venom variation in Mojave Rattlesnakes ( Crotalus scutulatus scutulatus ) are limited and little is known about the biological and proteolytic activities in this species. Tissue (34) and venom (29) samples were obtained from C. s. scutulatus from different locations within their distribution in Mexico. Mojave toxin detection was carried out at the genomic (by PCR) and protein (by ELISA) levels for all tissue and venom samples. Biological activity was tested on representative venoms by measuring LD 50 and hemorrhagic activity. To determine the approximate amount of SVMPs, 15 venoms were separated by RP-HPLC and variation in protein profile and proteolytic activity was evaluated by SDS-PAGE ( n = 28) and Hide Powder Azure proteolytic analysis ( n = 27). Three types of venom were identified in Mexico which is comparable to the intraspecific venom diversity observed in the Sonoran Desert of Arizona, USA: Venom Type A (∼Type II), with Mojave toxin, highly toxic, lacking hemorrhagic activity, and with scarce proteolytic activity; Type B (∼Type I), without Mojave toxin, less toxic than Type A, highly hemorrhagic and proteolytic; and Type A + B, containing Mojave toxin, as toxic as venom Type A, variable in hemorrhagic activity and with intermediate proteolytic activity. We also detected a positive correlation between SVMP abundance and hemorrhagic and proteolytic activities. Although more sampling is necessary, our results suggest that venoms containing Mojave toxin and venom lacking this toxin are distributed in the northwest and southeast portions of the distribution in Mexico, respectively, while an intergradation in the middle of both zones is present.

Biological and Proteolytic Variation in the Venom of Crotalus scutulatus scutulatus from Mexico

PubMed Central

Castañeda-Gaytán, Gamaliel; Castañeda-Gaytán, Juan; Ponce-López, Roberto; Olvera-Rodríguez, Alejandro; Alagón, Alejandro; Pérez-Morales, Rebeca

2018-01-01

Rattlesnake venoms may be classified according to the presence/absence and relative abundance of the neurotoxic phospholipases A2s (PLA2s), such as Mojave toxin, and snake venom metalloproteinases (SVMPs). In Mexico, studies to determine venom variation in Mojave Rattlesnakes (Crotalus scutulatus scutulatus) are limited and little is known about the biological and proteolytic activities in this species. Tissue (34) and venom (29) samples were obtained from C. s. scutulatus from different locations within their distribution in Mexico. Mojave toxin detection was carried out at the genomic (by PCR) and protein (by ELISA) levels for all tissue and venom samples. Biological activity was tested on representative venoms by measuring LD50 and hemorrhagic activity. To determine the approximate amount of SVMPs, 15 venoms were separated by RP-HPLC and variation in protein profile and proteolytic activity was evaluated by SDS-PAGE (n = 28) and Hide Powder Azure proteolytic analysis (n = 27). Three types of venom were identified in Mexico which is comparable to the intraspecific venom diversity observed in the Sonoran Desert of Arizona, USA: Venom Type A (∼Type II), with Mojave toxin, highly toxic, lacking hemorrhagic activity, and with scarce proteolytic activity; Type B (∼Type I), without Mojave toxin, less toxic than Type A, highly hemorrhagic and proteolytic; and Type A + B, containing Mojave toxin, as toxic as venom Type A, variable in hemorrhagic activity and with intermediate proteolytic activity. We also detected a positive correlation between SVMP abundance and hemorrhagic and proteolytic activities. Although more sampling is necessary, our results suggest that venoms containing Mojave toxin and venom lacking this toxin are distributed in the northwest and southeast portions of the distribution in Mexico, respectively, while an intergradation in the middle of both zones is present. PMID:29316683

As the raven flies: using genetic data to infer the history of invasive common raven (Corvus corax) populations in the Mojave Desert.

PubMed

Fleischer, Robert C; Boarman, William I; Gonzalez, Elena G; Godinez, Alvaro; Omland, Kevin E; Young, Sarah; Helgen, Lauren; Syed, Gracia; McIntosh, Carl E

2008-01-01

Common raven (Corvus corax) populations in Mojave Desert regions of southern California and Nevada have increased dramatically over the past five decades. This growth has been attributed to increased human development in the region, as ravens have a commensal relationship with humans and feed extensively at landfills and on road-killed wildlife. Ravens, as a partially subsidized predator, also represent a problem for native desert wildlife, in particular threatened desert tortoises (Gopherus agassizii). However, it is unclear whether the more than 15-fold population increase is due to in situ population growth or to immigration from adjacent regions where ravens have been historically common. Ravens were sampled for genetic analysis at several local sites within five major areas: the West Mojave Desert (California), East Mojave Desert (southern Nevada), southern coastal California, northern coastal California (Bay Area), and northern Nevada (Great Basin). Analyses of mtDNA control region sequences reveal an increased frequency of raven 'Holarctic clade' haplotypes from south to north inland, with 'California clade' haplotypes nearly fixed in the California populations. There was significant structuring among regions for mtDNA, with high F(ST) values among sampling regions, especially between the Nevada and California samples. Analyses of eight microsatellite loci reveal a mostly similar pattern of regional population structure, with considerably smaller, but mostly significant, values. The greater mtDNA divergences may be due to lower female dispersal relative to males, lower N(e), or effects of high mutation rates on maximal values of F(ST). Analyses indicate recent population growth in the West Mojave Desert and a bottleneck in the northern California populations. While we cannot rule out in situ population growth as a factor, patterns of movement inferred from our data suggest that the increase in raven populations in the West Mojave Desert resulted from movements from southern California and the Central Valley. Ravens in the East Mojave Desert are more similar to ones from northern Nevada, indicating movement between those regions. If this interpretation of high gene flow into the Mojave Desert is correct, then efforts to manage raven numbers by local control may not be optimally effective.

Concentrating Solar Power Projects - Mojave Solar Project | Concentrating

Science.gov Websites

Country: United States Location: Harper Dry Lake, California Owner(s): Mojave Solar, LLC Technology : Operational Country: United States City: Harper Dry Lake State: California County: San Bernardino Lat/Long

Land subsidence in the southwestern Mojave Desert, California, 1992–2009

USGS Publications Warehouse

Brandt, Justin; Sneed, Michelle

2017-07-19

Groundwater has been the primary source of domestic, agricultural, and municipal water supplies in the southwestern Mojave Desert, California, since the early 1900s. Increased demands on water supplies have caused groundwater-level declines of more than 100 feet (ft) in some areas of this desert between the 1950s and the 1990s (Stamos and others, 2001; Sneed and others, 2003). These water-level declines have caused the aquifer system to compact, resulting in land subsidence. Differential land subsidence (subsidence occurring at different rates across the landscape) can alter surface drainage routes and damage surface and subsurface infrastructure. For example, fissuring across State Route 247 at Lucerne Lake has required repairs as has pipeline infrastructure near Troy Lake.Land subsidence within the Mojave River and Morongo Groundwater Basins of the southwestern Mojave Desert has been evaluated using InSAR, ground-based measurements, geology, and analyses of water levels between 1992 and 2009 (years in which InSAR data were collected). The results of the analyses were published in three USGS reports— Sneed and others (2003), Stamos and others (2007), and Solt and Sneed (2014). Results from the latter two reports were integrated with results from other USGS/ MWA cooperative groundwater studies into the broader scoped USGS Mojave Groundwater Resources Web site (http://ca.water.usgs.gov/ mojave/). This fact sheet combines the detailed analyses from the three subsidence reports, distills them into a longer-term context, and provides an assessment of options for future monitoring.

Regional water table (2004) and water-level changes in the Mojave River and Morongo ground-water basins, Southwestern Mojave Desert, California

USGS Publications Warehouse

Stamos, Christina L.; Huff, Julia A.; Predmore, Steven K.; Clark, Dennis A.

2004-01-01

The Mojave River and Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water flow systems, and consequently, water availability. During March and April 2004, the U.S. Geological Survey and other agencies made almost 900 water-level measurements in about 740 wells in the Mojave River and Morongo ground-water basins. These data document recent conditions and, when compared with historical data, changes in ground-water levels. A water-level contour map was drawn using data from 500 wells, providing coverage for most of the basins. In addition, 26 long-term (as much as 74 years) hydrographs were constructed which show water-level conditions throughout the basins, 9 short-term (1992 to 2004) hydrographs were constructed which show the effects of recharge and discharge along the Mojave River, and a water-level-change map was compiled to compare 2002 and 2004 water levels throughout the basins. The water-level change data show that in the Mojave River ground-water basin, more than one half (102) of the wells had water-level declines of 0.5 ft or more and almost one fifth (32) of the wells had declines greater than 5 ft. between 2002 and 2004. The water-level change data also show that about one tenth (17) of the wells compared in the Mojave River ground-water basin had water level increases of 0.5 ft or more. Most of the water-level increases were the result of stormflow in the Mojave River during March 2004, which resulted in recharge to wells in the floodplain aquifer mainly along the river in the Alto subarea and the Transition zone, and along the river east of Barstow. In the Morongo ground-water basin, nearly one half (55) of the wells had water-level declines of 0.5 ft or more, and about one tenth (13) of the wells had declines greater than 5 ft. The Warren subbasin, where artificial-recharge operations in Yucca Valley (pl. 1) have caused water levels to rise, had water-level increases of as much as about 97 ft since 2002.

Geodetic slip rate for the eastern California shear zone and the recurrence time of Mojave desert earthquakes

USGS Publications Warehouse

Sauber, J.; Thatcher, W.; Solomon, S.C.; Lisowski, M.

1994-01-01

Where the San Andreas fault passes along the southwestern margin of the Mojave desert, it exhibits a large change in trend, and the deformation associated with the Pacific/North American plate boundary is distributed broadly over a complex shear zone. The importance of understanding the partitioning of strain across this region, especially to the east of the Mojave segment of the San Andreas in a region known as the eastern California shear zone (ECSZ), was highlighted by the occurrence (on 28 June 1992) of the magnitude 7.3 Landers earthquake in this zone. Here we use geodetic observations in the central Mojave desert to obtain new estimates for the rate and distribution of strain across a segment of the ECSZ, and to determine a coseismic strain drop of ~770 ??rad for the Landers earthquake. From these results we infer a strain energy recharge time of 3,500-5,000 yr for a Landers-type earthquake and a slip rate of ~12 mm yr-1 across the faults of the central Mojave. The latter estimate implies that a greater fraction of plate motion than heretofore inferred from geodetic data is accommodated across the ECSZ.

Alluvial Fans in Mojave Crater

NASA Image and Video Library

2015-05-20

This image from NASA Mars Reconnaissance Orbiter shows a landscape that is pervasively eroded, right up to the tops of the ridges, with channels extending down into depositional fans much like alluvial fans in the Mojave Desert.

California Coast

Atmospheric Science Data Center

2014-05-15

... shades of red. The distinctive chevron shape of the Mojave Desert is bordered by the San Andreas Fault on the south and the Garlock Fault ... March 14, 2000 - Southern California with the Mojave Desert and surrounding area. project:  MISR ...

Concentrating Solar Power Projects - Solar Electric Generating Station VIII

Science.gov Websites

: Harper Dry Lake, California (Mojave Desert) Owner(s): NextEra (50%) Technology: Parabolic trough Turbine City: Harper Dry Lake State: California County: San Bernardino Region: Mojave Desert Lat/Long Location

Recovery of compacted soils in Mojave Desert ghost towns.

USGS Publications Warehouse

Webb, R.H.; Steiger, J.W.; Wilshire, H.G.

1986-01-01

Residual compaction of soils was measured at seven sites in five Mojave Desert ghost towns. Soils in these Death Valley National Monument townsites were compacted by vehicles, animals, and human trampling, and the townsites had been completely abandoned and the buildings removed for 64 to 75 yr. Recovery times extrapolated using a linear recovery model ranged from 80 to 140 yr and averaged 100 yr. The recovery times were related to elevation, suggesting freeze-thaw loosening as an important factor in ameliorating soil compaction in the Mojave Desert. -from Authors

Hydrologic analysis of Mojave River Basin, California, using electric analog model

USGS Publications Warehouse

Hardt, W.F.

1971-01-01

The water needs of the Mojave River basin will increase because of population and industrial growth. The Mojave Water Agency is responsible for providing sufficient water of good quality for the full economic development of the area. The U.S. Geological Survey suggested an electric analog model of the basin as a predictive tool to aid management. About 1,375 square miles of the alluvial basin was simulated by a passive resistor-capacitor network. The Mojave River, the main source of recharge, was simulated by subdividing the river into 13 reaches, depending on intermittent or perennial flow and on phreatophytes. The water loss to the aquifer was based on records at five gaging stations. The aquifer system depends on river recharge to maintain the water table as most of the ground-water pumping and development is adjacent to the river. The accuracy and reliability of the model was assessed by comparing the water-level changes computed by the model for the period 1930-63 with the changes determined from field data for the same period. The model was used to predict the effects on the physical system by determining basin-wide water-level changes from 1930-2000 under different pumping rates and extremes in flow of the Mojave River. Future pumping was based on the 1960-63 rate, on an increase of 20 percent from this rate, and on population projections to 2000 in the Barstow area. For future predictions, the Mojave River was modeled as average flow based on 1931-65 records and also as high flow, 1937-46, and low flow, 1947-65. Other model runs included water-level change 1930-63 assuming aquifer depletion only and no recharge, effects of a well field pumping 10,000 acre-feet in 4 months north of Victorville and southeast of Yermo, and effects of importing 10,000, 35,000, and 50,800 acre-feet of water per year from the California Water Project into the Mojave River for conveyance downstream.

"Modeled and measured carbon cycling in Mojave Desert soils: toward present and projected greenhouse gas budgets for arid regions

NASA Astrophysics Data System (ADS)

Maurer, G. E.; Amundson, R.; Lammers, L. N.; Mills, J.; Oerter, E.

2017-12-01

Drylands comprise roughly 35% of the Earth's surface, store globally significant amounts of carbon, and cycle this carbon at rates that vary greatly from year to year. Consequently, drylands are thought to contribute to inter-annual changes in the global atmospheric CO2 budget. Sparse measurements and limited process-based modeling have made quantifying dryland carbon cycling at regional or larger scales a major challenge. We parameterized and ran the DayCent model, an ecosystem model that simulates soil C and N cycling and greenhouse gas (GHG) fluxes, using long-term regional climate, soil, and vegetation data for the Mojave Desert region (southwest USA). DayCent predicted somewhat greater soil organic C than was observed in a database of 186 measured Mojave soil survey samples, but successfully recreated climate-driven patterns in soil carbon storage across the landscape. Modeled soil organic carbon storage increased by between 4.1 and 5.1 kg/m2 per km of elevation gained, while Mojave soil survey data indicated an increase of 4.6 kg/m2. Model predictions of soil CO2 flux were validated and calibrated against field observations from ten Mojave soil gas profile studies sampled intermittently between 1986 and the present. DayCent had a tendency to overestimate soil respiration measured at some sites by up to 600% compared to profile measurements. Modeled soil CO2 fluxes increased by between 1280 and 4141 kg/ha/yr per km of elevation gained.This elevational pattern did not match well with landscape-level changes in observed soil profile CO2 flux data, indicating further calibration of DayCent will be needed to produce regional estimates of GHG flux. This ongoing synthesis of modeling and measurements extends the current knowledge of the Mojave's contribution to the global GHG budget and will provide a basis from which to project future emissions from the Mojave and other dryland regions.

Home in the heat: Dramatic seasonal variation in home range of desert golden eagles informs management for renewable energy development

USGS Publications Warehouse

Braham, Melissa A.; Miller, Tricia A.; Duerr, Adam E.; Lanzone, Michael J.; Fesnock, Amy; LaPre, Larry; Driscoll, Daniel; Katzner, Todd E.

2015-01-01

Renewable energy is expanding quickly with sometimes dramatic impacts to species and ecosystems. To understand the degree to which sensitive species may be impacted by renewable energy projects, it is informative to know how much space individuals use and how that space may overlap with planned development. We used global positioning system–global system for mobile communications (GPS-GSM) telemetry to measure year-round movements of golden eagles (Aquila chrysaetos) from the Mojave Desert of California, USA. We estimated monthly space use with adaptive local convex hulls to identify the temporal and spatial scales at which eagles may encounter renewable energy projects in the Desert Renewable Energy Conservation Plan area. Mean size of home ranges was lowest and least variable from November through January and greatest in February–March and May–August. These monthly home range patterns coincided with seasonal variation in breeding ecology, habitat associations, and temperature. The expanded home ranges in hot summer months included movements to cooler, prey-dense, mountainous areas characterized by forest, grasslands, and scrublands. Breeding-season home ranges (October–May) included more lowland semi-desert and rock vegetation. Overlap of eagle home ranges and focus areas for renewable energy development was greatest when eagle home ranges were smallest, during the breeding season. Golden eagles in the Mojave Desert used more space and a wider range of habitat types than expected and renewable energy projects could affect a larger section of the regional population than was previously thought.

Regional water table (2016) in the Mojave River and Morongo groundwater basins, southwestern Mojave Desert, California

USGS Publications Warehouse

Dick, Meghan; Kjos, Adam

2017-12-07

From January to April 2016, the U.S. Geological Survey (USGS), the Mojave Water Agency, and other local water districts made approximately 1,200 water-level measurements in about 645 wells located within 15 separate groundwater basins, collectively referred to as the Mojave River and Morongo groundwater basins. These data document recent conditions and, when compared with older data, changes in groundwater levels. A water-level contour map was drawn using data measured in 2016 that shows the elevation of the water table and general direction of groundwater movement for most of the groundwater basins. Historical water-level data stored in the USGS National Water Information System (https://waterdata.usgs.gov/nwis/) database were used in conjunction with data collected for this study to construct 37 hydrographs to show long-term (1930–2016) and short-term (1990–2016) water-level changes in the study area.

Inventory of amphibians and reptiles at Death Valley National Park

USGS Publications Warehouse

Persons, Trevor B.; Nowak, Erika M.

2006-01-01

As part of the National Park Service Inventory and Monitoring Program in the Mojave Network, we conducted an inventory of amphibians and reptiles at Death Valley National Park in 2002-04. Objectives for this inventory were to: 1) Inventory and document the occurrence of reptile and amphibian species occurring at DEVA, primarily within priority sampling areas, with the goal of documenting at least 90% of the species present; 2) document (through collection or museum specimen and literature review) one voucher specimen for each species identified; 3) provide a GIS-referenced list of sensitive species that are federally or state listed, rare, or worthy of special consideration that occur within priority sampling locations; 4) describe park-wide distribution of federally- or state-listed, rare, or special concern species; 5) enter all species data into the National Park Service NPSpecies database; and 6) provide all deliverables as outlined in the Mojave Network Biological Inventory Study Plan. Methods included daytime and nighttime visual encounter surveys, road driving, and pitfall trapping. Survey effort was concentrated in predetermined priority sampling areas, as well as in areas with a high potential for detecting undocumented species. We recorded 37 species during our surveys, including two species new to the park. During literature review and museum specimen database searches, we recorded three additional species from DEVA, elevating the documented species list to 40 (four amphibians and 36 reptiles). Based on our surveys, as well as literature and museum specimen review, we estimate an overall inventory completeness of 92% for Death Valley and an inventory completeness of 73% for amphibians and 95% for reptiles. Key Words: Amphibians, reptiles, Death Valley National Park, Inyo County, San Bernardino County, Esmeralda County, Nye County, California, Nevada, Mojave Desert, Great Basin Desert, inventory, NPSpecies.

Masten Xombie for Testing of JPL Spacecraft-Landing Algorithm

NASA Image and Video Library

2013-08-12

A Xombie technology demonstrator from Masten Space Systems, Mojave, Calif., ascends from its pad at Mojave Air and Space Port on a test for NASA Jet Propulsion Laboratory. The vehicle is a vertical-takeoff, vertical-landing experimental rocket.

Reconstructing late Pliocene to middle Pleistocene Death Valley lakes and river systems as a test of pupfish (Cyprinodontidae) dispersal hypotheses

USGS Publications Warehouse

Knott, J.R.; Machette, M.N.; Klinger, R.E.; Sarna-Wojcicki, A. M.; Liddicoat, J.C.; Tinsley, J. C.; David, B.T.; Ebbs, V.M.

2008-01-01

During glacial (pluvial) climatic periods, Death Valley is hypothesized to have episodically been the terminus for the Amargosa, Owens, and Mojave Rivers. Geological and biological studies have tended to support this hypothesis and a hydrological link that included the Colorado River, allowing dispersal of pupfish throughout southeastern California and western Nevada. Recent mitochondrial deoxyribonucleic acid (mtDNA) studies show a common pupfish (Cyprinodontidae) ancestry in this region with divergence beginning 3-2 Ma. We present tephrochronologic and paleomagnetic data in the context of testing the paleohydrologic connections with respect to the common collection point of the Amargosa, Owens, and Mojave Rivers in Death during successive time periods: (1) the late Pliocene to early Pleistocene (3-2 Ma), (2) early to middle Pleistocene (1.2-0.5 Ma), and (3) middle to late Pleistocene (<0.70.03 Ma; paleolakes Manly and Mojave). Using the 3.35 Ma Zabriskie Wash tuff and 3.28 Ma Nomlaki Tuff Member of the Tuscan and Tehama Formations, which are prominent marker beds in the region, we conclude that at 3-2 Ma, a narrow lake occupied the ancient Furnace Creek Basin and that Death Valley was not hydrologically connected with the Amargosa or Mojave Rivers. A paucity of data for Panamint Valley does not allow us to evaluate an Owens River connection to Death Valley ca. 3-2 Ma. Studies by others have shown that Death Valley was not hydrologically linked to the Amargosa, Owens, or Mojave Rivers from 1.2 to 0.5 Ma. We found no evidence that Lake Manly flooded back up the Mojave River to pluvial Lake Mojave between 0.18 and 0.12 Ma, although surface water flowed from the Amargosa and Owens Rivers to Death Valley at this time. There is also no evidence for a connection of the Owens, Amargosa, or Mojave Rivers to the Colorado River in the last 3-2 m.y. Therefore, the hypothesis that pupfish dispersed or were isolated in basins throughout southeastern California and western Nevada by such a connection is not supported. Beyond the biologically predicted time frame, however, sparse and disputed data suggest that a fluvial system connected Panamint (Owens River), Death, and Amargosa Valleys, which could account for the dispersal and isolation before 3 Ma. ?? 2008 The Geological Society of America.

Simulation of ground-water flow in the Mojave River basin, California

USGS Publications Warehouse

Stamos, Christina L.; Martin, Peter; Nishikawa, Tracy; Cox, Brett F.

2001-01-01

The proximity of the Mojave River ground-water basin to the highly urbanized Los Angeles region has led to rapid growth in population and, consequently, to an increase in the demand for water. The Mojave River, the primary source of surface water for the region, normally is dry-except for a small stretch of perennial flow and periods of flow after intense storms. Thus, the region relies almost entirely on ground water to meet its agricultural and municipal needs. Ground-water withdrawal since the late 1800's has resulted in discharge, primarily from pumping wells, that exceeds natural recharge. To better understand the relation between the regional and the floodplain aquifer systems and to develop a management tool that could be used to estimate the effects that future stresses may have on the ground-water system, a numerical ground-water flow model of the Mojave River ground-water basin was developed, in part, on the basis of a previously developed analog model. The ground-water flow model has two horizontal layers; the top layer (layer 1) corresponds to the floodplain aquifer and the bottom layer (layer 2) corresponds to the regional aquifer. There are 161 rows and 200 columns with a horizontal grid spacing of 2,000 by 2,000 feet. Two stress periods (wet and dry) per year are used where the duration of each stress period is a function of the occurrence, quantity of discharge, and length of stormflow from the headwaters each year. A steady-state model provided initial conditions for the transient-state simulation. The model was calibrated to transient-state conditions (1931-94) using a trial-and-error approach. The transient-state simulation results are in good agreement with measured data. Under transient-state conditions, the simulated floodplain aquifer and regional aquifer hydrographs matched the general trends observed for the measured water levels. The simulated streamflow hydrographs matched wet stress period average flow rates and times of no flow at the Barstow and Afton Canyon gages. Steady-state particle-tracking was used to estimate travel times for mountain-front and streamflow recharge. The simulated travel times for mountain-front recharge to reach the area west of Victorville were about 5,000 to 6,000 years; this result is in reasonable agreement with published results. Steady-state particle-tracking results for streamflow recharge indicate that in most subareas along the river, the particles quickly leave and reenter the river. The complaint that resulted in the adjudication of the Mojave River ground-water basin alleged that the cumulative water production upstream of the city of Barstow had overdrafted the ground-water basin. In order to ascertain the effect of pumping on ground-water and surface-water relations along the Mojave River, two pumping simulations were compared with the 1931-90 transient-state simulation (base case). The first simulation assumed 1931-90 pumping in the upper region (Este, Oeste, Alto, and Transition zone model subareas) but with no pumping in the remainder of the basin, and the second assumed 1931-90 pumping in the lower region (Centro, Harper Lake, Baja, Coyote Lake, and Afton Canyon model subareas) but with no pumping in remainder of the basin. In the upper region, assuming pumping only in the upper region, there was no change in storage, recharge from the Mojave River, ground-water discharge to the Mojave River, or evapotranspiration when compared with the base case. In the lower region, assuming pumping only in the upper region, there was storage accretion, decreased recharge from the Mojave River, increased ground-water discharge to the Mojave River, and increased evapotranspiration when compared with the base case. In the upper region, assuming pumping only in the lower region, there was storage accretion, decreased recharge from the Mojave River, increased ground-water discharge to the Mojave River, and increased evapotranspiration when compared with the base case. In the

Curiosity Conducting Mini-Drill Test at Mojave

NASA Image and Video Library

2015-01-14

This view NASA Curiosity Mars Rover shows the rover drill in position for a mini-drill test to assess whether a rock target called Mojave is appropriate for full-depth drilling to collect a sample. It was taken on Jan. 13, 2015.

Environmental effects of solar-thermal-power systems. Systematic status of the Mojave ground squirrel, Spermophilus mohavensis (subgenus Xerospermophilus)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hafner, D.J.; Yates, T.L.

1982-06-01

The Mojave ground squirrel, Spermophilus mohavensis, is listed as a rare species by the California Fish and Game Commission. Its well-being has emerged as an environmental concern associated with deployment of solar thermal power systems in western parts of the Mojave Desert. The more common round-tailed ground squirrel, Spermophilus tereticaudus, also occurs in the Mojave Desert, and this species closely resembles S. mohavensis. In some areas it may be extremely difficult, on the basis of external characters, to identify the species present. The systematic status of the sibling species Spermophilus mohavensis and S. tereticaudus (subgenus Xerosphermophilus) was investigated throughout themore » range of the subgenus, based on allozymic and chromosomal data. Hybridization of the two species was detected only at a single disturbed site, while allelic introgression was confined to an estimated 60 km reach of the Mojave River wash. In the absence of an analysis of a zone of natural sympatry, the two taxa are retained as full biological species. The population of ground squirrels just east of Solar One, the 10 MWe pilot solar thermal power plant, is composed of individuals referable to S. tereticaudus based on both allozymic and chromosomal criteria.« less

Nevada Test Site Resource Management Plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1998-12-01

The Nevada Test Site (NTS) Resource Management Plan (RMP) describes the NTS Stewardship Mission and how its accomplishment will preserve the resources of the ecoregion while accomplishing the objectives of the mission. The NTS Stewardship Mission is to manage the land and facilities at the NTS as a unique and valuable national resource. The RMP has defined goals for twelve resource areas based on the principles of ecosystem management. These goals were established using an interdisciplinary team of DOE/NV resource specialists with input from surrounding land managers, private parties, and representatives of Native American governments. The overall goal of themore » RMP is to facilitate improved NTS land use management decisions within the Great Basin and Mojave Desert ecoregions.« less

AMPHIBIAN DECLINES AND ENVIRONMENTAL CHANGE IN THE EASTERN "MOJAVE DESERT"

EPA Science Inventory

A number of amphibian species historically inhabited sparsely distributed wetlands in the Mojave Desert, USA, habitats that have been dramatically altered or eliminated as a result of human activities. The population status and distribution of amphibians were investigated in a 20...

MOJAVE DESERT SPRING: THE AMPHIBIAN POINT OF VIEW

EPA Science Inventory

Numerous springs are scattered throughout the eastern Mojave Desert, most of which are concentrated near the bases of mountain ranges. Spring-fed wetlands in this region comprise nearly all the available habitat for amphibians. We surveyed 128 springs for amphibians and habitat t...

Assessing the Benefits of Urban Forestry in Mojave Desert Communities

EPA Science Inventory

As the climate and environment change due to human activity, an understanding of the existing natural resources becomes paramount. Urban forests of Mojave Desert communities have the potential to reduce air pollution, heat island effects, and energy consumption. Regions throughou...

Who's hot, who's not? Effects of concentrating solar power heliostats on soil temperature at Ivanpah Solar Electric Generating System, Mojave Desert, USA

NASA Astrophysics Data System (ADS)

Grodsky, S.; Hernandez, R. R.

2017-12-01

Solar energy development may function as a contemporary, anthropogenic driver of disturbance when sited in natural ecosystems. Orientation and density of solar modules, including heliostats at concentrating solar power (CSP) facilities, may affect soils via shading and altered surface-water flow. Meanwhile, soil attributes like temperature and moisture may affect nutrient cycling, plant germination and growth, and soil biota. We tested effects of CSP heliostats on soil temperature at Ivanpah Solar Electric Generating System (ISEGS) in the Mojave Desert, USA. We implemented experimental treatments based on preconstruction rare plant [e.g., Mojave milkweed (Asclepias nyctaginifolia)] protection areas (hereafter "halos"), site preparation activities, and heliostat density throughout three, replicated CSP blocks (i.e., tower and associated heliostats), including: (1) No Halos (Bladed) - high site preparation intensity, high heliostat density immediately surrounding towers; (2) No Halos (Mowed) - moderate site preparation intensity, moderate to low heliostat density as distance increases from towers; and (3) Halos - no site preparation, no heliostats. We also established control sites within 1,600 km of ISEGS in undisturbed desert. We observed significant differences in soil temperature across treatments. We recorded significantly lower soil temperatures in the No Halos (Bladed) treatments (26.7°C) and No Halos (Mowed) treatments (29.9°C) than in the Halos treatments (32.9°C) and controls (32.1°C). We also determined that soil temperatures in the Halos treatments and controls did not significantly differ. Our results indicated that shading from high-density heliostat configuration significantly reduced soil temperature relative to low-density heliostat configuration and areas without CSP. Shading from heliostats and consequential fluctuation in soil temperatures may affect local-scale distribution of flora and fauna, leading to altered "bottom-up" ecological interactions at ISEGS.

Early Proterozoic ties between two suspect terranes and the Mojave crustal block of the Southwestern U.S

USGS Publications Warehouse

Bender, E. Erik; Morrison, Jean; Anderson, J. Lawford; Wooden, Joseph L.

1993-01-01

Southern California and adjacent areas contain two suspect or exotic terranes comprised largely of ancient continental crust, namely the Tujunga (San Gabriel) and Joshua Tree terranes, that have been considered part of a larger displaced terrane, the Santa Lucia-Orocopia allochthon. Paleomagnetic data for the allochthon indicate northward transport in excess of 2000 km and, thus, an origin extraneous to North America. However, Early Proterozoic plutons of the Mojave crustal block and the Joshua Tree and Tujunga terranes have strikingly comparable features, including: (1) crystallization ages of 1.63 to 1.68 Ga; (2) biotite + sphene + magnetite hornblende garnet mineralogy; (3) high LIL and enriched HFS elemental composition; (4) WPG (within-plate granite) trace element chemistry; (5) similar and unique oxygen isotopic compositions; and (6) distinct Pb and Nd isotopic signatures. These features of the Mojave block, which clearly originated as part of native North America, nevertheless distinguish it from crust elsewhere in North America. On the basis of data presented here, we conclude that the Tujunga terrane is a disrupted portion of the Mojave crustal block and is neither far-traveled nor exotic to North America. Its apparent "exotic" nature stems from derivation out of the middle crust. We also conclude that the Joshua Tree terrane is correlative to the Mojave block. We have found no significant evidence for its displacement and consider Joshua Tree to be contiguous with the Mojave block and thus not a valid terrane. The Tujunga (San Gabriel) and Joshua Tree terranes should not be considered as part of, or having shared the same transport as, the Santa Lucia-Orocopia allocthon.

Regional Water Table (1998) and Ground-Water-Level Changes in the Mojave River, and the Morongo Ground-Water Basins, San Bernardino County, California

USGS Publications Warehouse

Smith, Gregory A.; Pimentel, M. Isabel

2000-01-01

The Mojave River and the Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The rapid and continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The continuing collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water systems and, consequently, water availability. During 1998 the U.S. Geological Survey and other agencies made approximately 2,370 water-level measurements in the Mojave River and the Morongo ground-water basins. These data document recent conditions and changes in ground-water levels. A water-level contour map was drawn using data from 450 wells, providing coverage for most of both basins. Twenty-three hydrographs show long-term (as much as 70 years) water-level trends throughout the basins. To help show effects of late seasonal recharge along the Mojave River, 14 short-term (13 years) hydrographs were created. A water-level change map was compiled to enable comparison of 1996 and 1998 water levels. The Mojave River and the Morongo ground-water basins had little change in water levels between 1996 and 1998 - with the exception of the areas of the Yucca Valley affected by artificial recharge. Other water-level changes were localized and reflected pumping or measurements made before seasonal recharge. Three areas of perched ground water were identified: El Mirage Lake (dry), Adelanto, and Lucerne Valley.

Riparian vegetation and its water use during 1995 along the Mojave River, Southern California

USGS Publications Warehouse

Lines, Gregory C.; Bilhorn, Thomas W.

1996-01-01

The extent and areal density of riparian vegetation, including both phreatophytes and hydrophytes, were mapped along the 100-mile main stem of the Mojave River during 1995. Mapping was aided by vertical false-color infrared and low-level oblique photographs. However, positive identification of plant species and plant physiological stress required field examination. The consumptive use of ground water and surface water by different areal densities of riparian plant communities along the main stem of the Mojave River was estimated using water-use data from a select group of studies in the southwestern United States. In the Alto subarea of the Mojave basin management area, consumptive water use during 1995 by riparian vegetation was estimated to be about 5,000 acre-feet upstream from the Lower Narrows and about 6,000 acre-feet downstream in the transition zone. In the Centro and Baja subareas, consumptive water use was estimated to be about 3,000 acre-feet and 2,000 acre-feet, respectively, during 1995. Consumptive water use by riparian vegetation in the Afton area, downstream from the Baja subarea, was estimated to be about 600 acre-feet during 1995. Consumptive water use by riparian vegetation during 1995 is considered representative of "normal" hydrologic conditions along the Mojave River. Barring major changes in the areal extent and density of riparian vegetation, the 1995 consumptive-use estimates should be fairly representative of riparian vegetation water use during most years. Annual consumptive use, however, could vary from the 1995 estimates as much as plus or minus 50 percent because of extreme hydrologic conditions (periods of high water table following extraordinarily large runoff in the Mojave River or periods of extended drought).

Interseismic strain and rotation rates in the northeast Mojave domain, eastern California

USGS Publications Warehouse

Savage, J.C.; Svarc, J.L.; Prescott, II W.

2004-01-01

The northeast Mojave domain, a type locality for bookshelf faulting, is a region of east striking, left-lateral faults in the northeast comer of the Mojave block, a block otherwise dominated by ??N40??W striking, right-lateral faults. Paleomagnetic evidence suggests that blocks within the domain have rotated clockwise about a vertical axis as much as 60?? since 12.8 Ma [Schermer et al., 1996]. In 1994, and again in 2002, the U.S. Geological Survey surveyed an array of 14 geodetic monuments distributed across the northeast Mojave domain. The 2002 survey results were adjusted to remove the coseismic offsets imposed by the nearby Hector Mine earthquake (16 October 1999, Mw = 7.1). The adjusted deformation across the array appears to be uniform and can be approximated by the principal strain rates ??:1 = 28.9 ?? 9.1 N77.2??W ?? 4.8?? and ??2 = -48.2 ?? 8.9 N12.8??E ?? 4.8?? nstrain yr-1; extension reckoned positive, and quoted uncertainties are standard deviations. That strain accumulation could be released by slip . on faults striking N32??W but not by bookshelf faulting on the east striking faults alone. The vertical axis rotation rate of the northeast Mojave domain as a whole relative to fixed North America is 71.0 ?? 6.4 nrad yr-1 (4.07?? ?? 0.37?? Myr-1) clockwise, about twice the maximum tenser shear strain rate. The observed rotation rate acting over 12.8 Myr would produce'a clockwise rotation of 52.1?? ?? 4.7??, exclusive of possible coseismic rotations. That rotation is in rough agreement with the paleomagnetic rotation accumulated in the individual fault blocks within the northeast Mojave domain since 12.8 Ma.

LIVESTOCK GRAZING EFFECTS ON ANT COMMUNITIES IN THE EASTERN MOJAVE DESERT, USA

EPA Science Inventory

The effects of livestock grazing on composition and structure of ant communities were examined in the eastern Mojave Desert, USA for the purpose of evaluating ant communities as potential indicators of rangeland condition. Metrics for ant communities, vegetation, and other groun...

78 FR 35960 - Minor Boundary Revision at Mojave National Preserve

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-14

... DEPARTMENT OF THE INTERIOR National Park Service [NPS-PWR-MOJA-12321; PS.SMOJA0003] Minor Boundary Revision at Mojave National Preserve AGENCY: National Park Service, Interior. ACTION: Notification of... following locations: National Park Service, Land Resources Program Center, Pacific West Region, 333 Bush...

ERAST Program Proteus Aircraft in Flight over the Mojave Desert in California

NASA Image and Video Library

1999-07-26

The unusual design of the Proteus high-altitude aircraft, incorporating a gull-wing shape for its main wing and a long, slender forward canard, is clearly visible in this view of the aircraft in flight over the Mojave Desert in California.

DISTRIBUTIONAL CHANGES AND POPULATION STATUS FOR AMPHIBIANS IN THE EASTERN MOJAVE DESERT

EPA Science Inventory

A number of amphibian species historically inhabited sparsely distributed wetlands in the Mojave Desert of western North America, habitats that have been dramatically altered or eliminated as a result of human activities. The population status and distributional changes for amphi...

Monoclonal antibodies to Mojave toxin and use for isolation of cross-reacting proteins in Crotalus venoms.

PubMed

Rael, E D; Salo, R J; Zepeda, H

1986-01-01

Hybridomas secreting monoclonal antibodies against Mojave toxin were established. The antibodies were used for identifying cross-reacting proteins in individual C. s. scutulatus and other Crotalus venoms and to isolate Mojave toxin. The antibodies recognized five bands with a pI range from 5.1 to 6.1 in immunoblots of electrofocused crude venom and Mojave toxin purified by immunoaffinity chromatography. The specificity of the antibodies was for the basic subunit of the toxin, which resolved into four bands of pI between 9.3 and 9.6. Individual C. s. scutulatus venoms of snakes from Texas and southern Arizona had multiple bands with pI's ranging from 4.9 to 6.3. Cross-reacting proteins were also recognized by the antibodies in the electrophoresed venoms of C. basiliscus, C. d. durissus, C. d. terrificus, C. h. horridus and C. v. concolor, and may be isolated by immunoaffinity chromatography with the monoclonal antibodies.

The Mojave vadose zone: a subsurface biosphere analogue for Mars.

PubMed

Abbey, William; Salas, Everett; Bhartia, Rohit; Beegle, Luther W

2013-07-01

If life ever evolved on the surface of Mars, it is unlikely that it would still survive there today, but as Mars evolved from a wet planet to an arid one, the subsurface environment may have presented a refuge from increasingly hostile surface conditions. Since the last glacial maximum, the Mojave Desert has experienced a similar shift from a wet to a dry environment, giving us the opportunity to study here on Earth how subsurface ecosystems in an arid environment adapt to increasingly barren surface conditions. In this paper, we advocate studying the vadose zone ecosystem of the Mojave Desert as an analogue for possible subsurface biospheres on Mars. We also describe several examples of Mars-like terrain found in the Mojave region and discuss ecological insights that might be gained by a thorough examination of the vadose zone in these specific terrains. Examples described include distributary fans (deltas, alluvial fans, etc.), paleosols overlain by basaltic lava flows, and evaporite deposits.

A kinematic model for the evolution of the Eastern California Shear Zone and Garlock Fault, Mojave Desert, California

NASA Astrophysics Data System (ADS)

Dixon, Timothy H.; Xie, Surui

2018-07-01

The Eastern California shear zone in the Mojave Desert, California, accommodates nearly a quarter of Pacific-North America plate motion. In south-central Mojave, the shear zone consists of six active faults, with the central Calico fault having the fastest slip rate. However, faults to the east of the Calico fault have larger total offsets. We explain this pattern of slip rate and total offset with a model involving a crustal block (the Mojave Block) that migrates eastward relative to a shear zone at depth whose position and orientation is fixed by the Coachella segment of the San Andreas fault (SAF), southwest of the transpressive "big bend" in the SAF. Both the shear zone and the Garlock fault are assumed to be a direct result of this restraining bend, and consequent strain redistribution. The model explains several aspects of local and regional tectonics, may apply to other transpressive continental plate boundary zones, and may improve seismic hazard estimates in these zones.

Water-Level and land-subsidence studies in the Mojave River and Morongo groundwater basins

USGS Publications Warehouse

Stamos, Christina L.; Glockhoff, Carolyn S.; McPherson, Kelly R.; Julich, Raymond J.

2007-01-01

What's New! Water-level data, contours, and meta data for spring 2008 are included in Version 2.0 of SIR 2007-5097 (http://ca.water.usgs.gov/mojave/wl_studies/wl2008.html). All the original data are still available on the web site. Introduction Since 1992, the U.S. Geological Survey (USGS), in cooperation with the Mojave Water Agency (MWA), has constructed a series of regional water-table maps for intermittent years in a continuing effort to monitor groundwater conditions in the Mojave River and Morongo groundwater basins. The previously published data, which were used to construct these maps, can be accessed on the interactive map. The associated reports describing the groundwater conditions for the Mojave River groundwater basin for 1992 (Stamos and Predmore, 1995), the Morongo groundwater basin for 1994 (Trayler and Koczot, 1995), and for both groundwater basins for 1996 (Mendez and Christensen, 1997); for 1998 (Smith and Pimentel, 2000), for 2000 (Smith, 2002), for 2002 (Smith and others, 2004), for 2004 (Stamos and others, 2004), and for 2006 (Stamos and others, 2007) can be accessed using this web site. Spatially detailed maps of interferometric synthetic aperture radar (InSAR) methods were used to characterize land subsidence associated with groundwater-level declines during various intervals of time between 1992 and 1999 in the Mojave River and Morongo groundwater basins (Sneed and others, 2003). Concerns related to the potential for new or renewed land subsidence in the basins resulted in a cooperative study between the MWA and the USGS in 2006. InSAR data were developed to determine the location, extent, and magnitude of vertical land-surface changes in the Mojave River and Morongo groundwater basins for time intervals ranging from about 35 days to 14 months between 1999 and 2000 and between 2003 and 2004. (interactive Google map) The results from many future land-subsidence studies, which are scheduled about every 10 years, will be available on this website. Mapping of water-level contours, water-level change and numerous InSAR images were combined in an interactive map. This interactive map may be customized to your needs and viewed at a scale that is appropriate for the data.

Regional Water Table (2002) and Water-Level Changes in the Mojave River and Morongo Ground-Water Basins, Southwestern Mojave Desert, California

USGS Publications Warehouse

Smith, Gregory A.; Stamos, Christina L.; Predmore, Steven K.

2004-01-01

The Mojave River and Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water flow systems, and consequently, water availability. During 2002, the U.S. Geological Survey and other agencies made approximately 2,500 water-level measurements in the Mojave River and Morongo ground-water basins. These data document recent conditions and, when compared with previous data, changes in ground-water levels. A water-level contour map was drawn using data from about 600 wells, providing coverage for most of the basins. Twenty-eight hydrographs show long-term (up to 70 years) water-level conditions throughout the basins, and 9 short-term (1997 to 2002) hydrographs show the effects of recharge and discharge along the Mojave River. In addition, a water-level-change map was compiled to compare 2000 and 2002 water levels throughout the basins. In the Mojave River ground-water basin, about 66 percent of the wells had water-level declines of 0.5 ft or more since 2000 and about 27 percent of the wells had water-level declines greater than 5 ft. The only area that had water-level increases greater than 5 ft that were not attributed to fluctuations in nearby pumpage was in the Harper Lake (dry) area where there has been a significant reduction in pumpage during the last decade. In the Morongo ground-water basin, about 36 percent of the wells had water-level declines of 0.5 ft or more and about 10 percent of the wells had water-level declines greater than 5 ft. Water-level increases greater than 5 ft were measured only in the Warren subbasin, where artificial-recharge operations have caused water levels to rise almost 60 ft since 2000.

Mammal Inventory of the Mojave Network Parks-Death Valley and Joshua Tree National Parks, Lake Mead National Recreation Area, Manzanar National Historic Site, and Mojave National Preserve

USGS Publications Warehouse

Drost, Charles A.; Hart, Jan

2008-01-01

This report describes the results of a mammal inventory study of National Park Service units in the Mojave Desert Network, including Death Valley National Park, Joshua Tree National Park, Lake Mead National Recreation Area, Manzanar National Historic Site, and Mojave National Preserve. Fieldwork for the inventory focused on small mammals, primarily rodents and bats. Fieldwork for terrestrial small mammals used trapping with Sherman and Tomahawk small- and medium-sized mammal traps, along with visual surveys for diurnal species. The majority of sampling for terrestrial small mammals was carried out in 2002 and 2003. Methods used in field surveys for bats included mist-netting at tanks and other water bodies, along with acoustic surveys using Anabat. Most of the bat survey work was conducted in 2003. Because of extremely dry conditions in the first two survey years (and associated low mammal numbers), we extended field sampling into 2004, following a relatively wet winter. In addition to field sampling, we also reviewed, evaluated, and summarized museum and literature records of mammal species for all of the Park units. We documented a total of 59 mammal species as present at Death Valley National Park, with an additional five species that we consider of probable occurrence. At Joshua Tree, we also documented 50 species, and an additional four 'probable' species. At Lake Mead National Recreation Area, 57 mammal species have been positively documented, with 10 additional probable species. Manzanar National Historic Site had not been previously surveyed. We documented 19 mammal species at Manzanar, with an additional 11 probable species. Mojave National Preserve had not had a comprehensive list previously, either. There are now a total of 50 mammal species documented at Mojave, with three additional probable species. Of these totals, 23 occurrences are new at individual park units (positively documented for the first time), with most of these being at Manzanar. Noteworthy additions include western mastiff bat at Joshua Tree, house mouse at a number of wildland sites at Lake Mead, and San Diego pocket mouse at Mojave National Preserve. There are also species that have been lost from the Mojave Network parks. We discuss remaining questions, including the possible occurrence of additional species at each park area (most of these are marginal species whose distributional range may or may not edge into the boundaries of the area). Taxonomic changes are also discussed, along with potential erroneous species records.

Evidence for crustal degassing of CF4 and SF6 in Mojave Desert groundwaters

USGS Publications Warehouse

Deeds, D.A.; Vollmer, M.K.; Kulongoski, J.T.; Miller, B.R.; Muhle, J.; Harth, C.M.; Izbicki, J.A.; Hilton, David R.; Weiss, R.F.

2008-01-01

Dissolved tetrafluoromethane (CF4) and sulfur hexafluoride (SF6) concentrations were measured in groundwater samples from the Eastern Morongo Basin (EMB) and Mojave River Basin (MRB) located in the southern Mojave Desert, California. Both CF4 and SF6 are supersaturated with respect to equilibrium with the preindustrial atmosphere at the recharge temperatures and elevations of the Mojave Desert. These observations provide the first in situ evidence for a flux of CF4 from the lithosphere. A gradual basin-wide enhancement in dissolved CF4 and SF6 concentrations with groundwater age is consistent with release of these gases during weathering of the surrounding granitic alluvium. Dissolved CF4 and SF6 concentrations in these groundwaters also contain a deeper crustal component associated with a lithospheric flux entering the EMB and MRB through the underlying basement. The crustal flux of CF4, but not of SF6, is enhanced in the vicinity of local active fault systems due to release of crustal fluids during episodic fracture events driven by local tectonic activity. When fluxes of CF4 and SF6 into Mojave Desert groundwaters are extrapolated to the global scale they are consistent, within large uncertainties, with the fluxes required to sustain the preindustrial atmospheric abundances of CF4 and SF6. ?? 2007 Elsevier Ltd. All rights reserved.

Chasing the Garlock: A study of tectonic response to vertical axis rotation

NASA Astrophysics Data System (ADS)

Guest, Bernard; Pavlis, Terry L.; Golding, Heather; Serpa, Laura

2003-06-01

Vertical-axis, clockwise block rotations in the Northeast Mojave block are well documented by numerous authors. However, the effects of these rotations on the crust to the north of the Northeast Mojave block have remained unexplored. In this paper we present a model that results from mapping and geochronology conducted in the north and central Owlshead Mountains. The model suggests that some or all of the transtension and rotation observed in the Owlshead Mountains results from tectonic response to a combination of clockwise block rotation in the Northeast Mojave block and Basin and Range extension. The Owlshead Mountains are effectively an accommodation zone that buffers differential extension between the Northeast Mojave block and the Basin and Range. In addition, our model explores the complex interactions that occur between faults and fault blocks at the junction of the Garlock, Brown Mountain, and Owl Lake faults. We hypothesize that the bending of the Garlock fault by rotation of the Northeast Mojave block resulted in a misorientation of the Garlock that forced the Owl Lake fault to break in order to accommodate slip on the western Garlock fault. Subsequent sinistral slip on the Owl Lake fault offset the Garlock, creating the now possibly inactive Mule Springs strand of the Garlock fault. Dextral slip on the Brown Mountain fault then locked the Owl Lake fault, forcing the active Leach Lake strand of the Garlock fault to break.

Landscape-scale distribution and density of raptor populations wintering in anthropogenic-dominated desert landscapes

USGS Publications Warehouse

Duerr, Adam E.; Miller, Tricia A.; Cornell Duerr, Kerri L; Lanzone, Michael J.; Fesnock, Amy; Katzner, Todd E.

2015-01-01

Anthropogenic development has great potential to affect fragile desert environments. Large-scale development of renewable energy infrastructure is planned for many desert ecosystems. Development plans should account for anthropogenic effects to distributions and abundance of rare or sensitive wildlife; however, baseline data on abundance and distribution of such wildlife are often lacking. We surveyed for predatory birds in the Sonoran and Mojave Deserts of southern California, USA, in an area designated for protection under the “Desert Renewable Energy Conservation Plan”, to determine how these birds are distributed across the landscape and how this distribution is affected by existing development. We developed species-specific models of resight probability to adjust estimates of abundance and density of each individual common species. Second, we developed combined-species models of resight probability for common and rare species so that we could make use of sparse data on the latter. We determined that many common species, such as red-tailed hawks, loggerhead shrikes, and especially common ravens, are associated with human development and likely subsidized by human activity. Species-specific and combined-species models of resight probability performed similarly, although the former model type provided higher quality information. Comparing abundance estimates with past surveys in the Mojave Desert suggests numbers of predatory birds associated with human development have increased while other sensitive species not associated with development have decreased. This approach gave us information beyond what we would have collected by focusing either on common or rare species, thus it provides a low-cost framework for others conducting surveys in similar desert environments outside of California.

Impacts of climate change and renewable energy development on habitat of an endemic squirrel, Xerospermophilus mohavensis, in the Mojave Desert, USA

USGS Publications Warehouse

Inman, Richard D.; Esque, Todd C.; Nussear, Kenneth E.; Leitner, Philip; Matocq, Marjorie D.; Weisberg, Peter J.; Dilts, Thomas E.

2016-01-01

Predicting changes in species distributions under a changing climate is becoming widespread with the use of species distribution models (SDMs). The resulting predictions of future potential habitat can be cast in light of planned land use changes, such as urban expansion and energy development to identify areas with potential conflict. However, SDMs rarely incorporate an understanding of dispersal capacity, and therefore assume unlimited dispersal in potential range shifts under uncertain climate futures. We use SDMs to predict future distributions of the Mojave ground squirrel, Xerospermophilus mohavensis Merriam, and incorporate partial dispersal models informed by field data on juvenile dispersal to assess projected impact of climate change and energy development on future distributions of X. mohavensis. Our models predict loss of extant habitat, but also concurrent gains of new habitat under two scenarios of future climate change. Under the B1 emissions scenario- a storyline describing a convergent world with emphasis on curbing greenhouse gas emissions- our models predicted losses of up to 64% of extant habitat by 2080, while under the increased greenhouse gas emissions of the A2 scenario, we suggest losses of 56%. New potential habitat may become available to X. mohavensis, thereby offsetting as much as 6330 km2 (50%) of the current habitat lost. Habitat lost due to planned energy development was marginal compared to habitat lost from changing climates, but disproportionately affected current habitat. Future areas of overlap in potential habitat between the two climate change scenarios are identified and discussed in context of proposed energy development.

Mojave Desert Diary

ERIC Educational Resources Information Center

Breed, Allen F.

1974-01-01

This is an account of a trip to the Mojave Desert sponsored by the California Youth Authority's Community Parole Center for wards who are selected on the basis of their potential for growth and their ability to make a connection between what they do in the wilderness and what they do on the streets. (PD)

VizieR Online Data Catalog: MOJAVE XV. VLBA 15GHz obs. of AGN jets 1996-2016 (Lister+, 2018)

NASA Astrophysics Data System (ADS)

Lister, M. L.; Aller, M. F.; Aller, H. D.; Hodge, M. A.; Homan, D. C.; Kovalev, Y. Y.; Pushkarev, A. B.; Savolainen, T.

2018-03-01

The VLBA maps in this paper are of 437 compact, radio-loud AGNs observed as part of the MOJAVE program. The data consist of 5321 observations of 437 AGNs in the 15GHz band, obtained between 1996 January 19 and 2016 December 26 with the VLBA in full polarization mode (Table 2). Most of the VLBA observations (86%) were carried out as part of the MOJAVE program (Paper V; Lister+ 2009, J/AJ/137/3718), while the remainder were downloaded from the NRAO archive. Most of the AGNs have between 5 and 15 VLBA observation epochs, although a substantial number have considerably more epochs. (3 data files).

Creosotebush, blackbrush, and interior chaparral shrublands [Chapter 6

Treesearch

Matthew L. Brooks; Todd C. Esque; Tim Duck

2007-01-01

The vegetation, fire regime, and Fire Regime Condition Class descriptions in this paper apply broadly to the Mojave Desert, Colorado Plateau, and southern Great Basin of western North America. More detail on these topics, including estimated percentages within each condition class, is provided for the Mojave-Colorado Plateau ecotone spanning southern Nevada, the...

Comparison of ground-water flow model particle-tracking results and isotopic data in the Mojave River ground-water basin, southern California, USA

USGS Publications Warehouse

Izbicki, John A.; Stamos, Christina L.; Nishikawa, Tracy; Martin, Peter

2004-01-01

Flow-path and time-of-travel results for the Mojave River ground-water basin, southern California, calculated using the ground-water flow model MODFLOW and particle-tracking model MODPATH were similar to flow path and time-of-travel interpretations derived from delta-deuterium and carbon-14 data. Model and isotopic data both show short flow paths and young ground-water ages throughout the floodplain aquifer along most the Mojave River. Longer flow paths and older ground-water ages as great as 10,000 years before present were measured and simulated in the floodplain aquifer near the Mojave Valley. Model and isotopic data also show movement of water between the floodplain and regional aquifer and subsequent discharge of water from the river to dry lakes in some areas. It was not possible to simulate the isotopic composition of ground-water in the regional aquifer away from the front of the San Gabriel and San Bernardino Mountains - because recharge in these areas does not occur under the present-day climatic conditions used for calibration of the model.

Assembling and disassembling california: A zircon and monazite geochronologic framework for proterozoic crustal evolution in southern California

USGS Publications Warehouse

Barth, A.P.; Wooden, J.L.; Coleman, D.S.; Vogel, M.B.

2009-01-01

The Mojave province in southern California preserves a comparatively complete record of assembly, postorogenic sedimentation, and rifting along the southwestern North American continental margin. The oldest exposed rocks are metasedimentary gneisses and amphibolite, enclosing intrusive suites that range from tonalite and quartz mon-zodiorite to granite with minor trondhjemite. Discrete magmatic episodes occurred at approximately 1790-1730 and 1690-1640 Ma. Evidence from detrital and premagmatic zircons indicates that recycling of 1900-1790 Ma Paleopro-terozoic crust formed the unique isotopic character of the Mojave province. Peak metamorphic conditions in the Mojave province reached middle amphibolite to granulite facies; metamorphism occurred locally from 1795 to 1640 Ma, with widespread evidence for metamorphism at 1711-1689 and 1670-1650 Ma. Structures record early, tight to isoclinal folding and penetrative west-vergent shear during the final metamorphic event in the west Mojave province. Proterozoic basement rocks are overlain by siliciclastic-carbonate sequences of Mesoproterozoic, Neoproterozoic, and Cambrian age, recording environmental change over the course of the transition from stable Mojave crust to the rifted Cordilleran margin. Neoproterozoic quartzites have diverse zircon populations inconsistent with a southwest North American source, which we infer were derived from the western conjugate rift pair within Rodinia, before establishment of the miogeocline. Neoproterozoic-Cambrian miogeoclinal clastic rocks record an end to rifting and establishment of the Cordilleran miogeocline in southern California by latest Neoproterozoic to Early Cambrian time. ?? 2009 by The University of Chicago.

Final Environmental Assessment for the Integrated Natural Resources Management Plan for Nellis Air Force Base, Creech Air Force Base, and the Nevada Test And Training Range, NV

DTIC Science & Technology

2008-06-01

a signifi- cant role in the Great Basin and Mojave Desert. The majority of these ecoregions are not impacted at NTTR with only 15% of the land area...designation of non-attainment for CO in Clark County. Recently, EPA has designated the Hydrographic Basin 212 boundary as defined by Clark County and...evaporation rates and low humidity (USAGE, 2001 ). All impoundments are man- made and located on the golf course. Water erosion is rare in the basin

Geochemical evidence for a complex origin for the Kelso dunes, Mojave National Preserve, California USA

USGS Publications Warehouse

Muhs, Daniel; Lancaster, Nicholas; Skipp, Gary L.

2017-01-01

The Kelso Dune field in southern California is intriguing because although it is of limited areal extent (~ 100 km2), it has a wide variety of dune forms and contains many active dunes (~ 40 km2), which is unusual in the Mojave Desert. Studies over the past eight decades have concluded that the dunes are derived primarily from a single source, Mojave River alluvium, under a dominant, westerly-to-northwesterly wind regime. The majority of these studies did not, however, present data to support the Mojave River as the only source. We conducted mineralogical and geochemical studies of most of the 14 geomorphically defined dune groups of the Kelso Dune field as well as potential sand sources, alluvial sediments from the surrounding mountain ranges. Results indicate that sands in the nine western dune groups have K/Rb and K/Ba (primarily from K-feldspar) compositions that are indistinguishable from Mojave River alluvium (westerly/northwesterly winds) and Budweiser Wash alluvium (southwesterly winds), permitting an interpretation of two sources. In contrast, sands from the five eastern dune groups have K/Rb and K/Ba values that indicate significant inputs from alluvial fan deposits of the Providence Mountains. This requires either rare winds from the east or southeast or, more likely, aeolian reworking of distal Providence Mountain fan sediments by winds from the west, at a rate greater than input from the Mojave River or other western sources. The results indicate that even a small dune field can have a complex origin, either from seasonally varying winds or complex alluvial-fan-dune interaction. Application of K/Rb and K/Ba in K-feldspar as a provenance indicator could be used in many of the world's ergs or sand seas, where dune origins are still not well understood or are controversial. Four examples are given from Africa and the Middle East where such an approach could yield useful new information about dune sand provenance.

A complex origin for the Kelso Dunes, Mojave National Preserve, California, USA: A case study using a simple geochemical method with global applications

NASA Astrophysics Data System (ADS)

Muhs, Daniel R.; Lancaster, Nicholas; Skipp, Gary L.

2017-01-01

The Kelso Dune field in southern California is intriguing because although it is of limited areal extent ( 100 km2), it has a wide variety of dune forms and contains many active dunes ( 40 km2), which is unusual in the Mojave Desert. Studies over the past eight decades have concluded that the dunes are derived primarily from a single source, Mojave River alluvium, under a dominant, westerly-to-northwesterly wind regime. The majority of these studies did not, however, present data to support the Mojave River as the only source. We conducted mineralogical and geochemical studies of most of the 14 geomorphically defined dune groups of the Kelso Dune field as well as potential sand sources, alluvial sediments from the surrounding mountain ranges. Results indicate that sands in the nine western dune groups have K/Rb and K/Ba (primarily from K-feldspar) compositions that are indistinguishable from Mojave River alluvium (westerly/northwesterly winds) and Budweiser Wash alluvium (southwesterly winds), permitting an interpretation of two sources. In contrast, sands from the five eastern dune groups have K/Rb and K/Ba values that indicate significant inputs from alluvial fan deposits of the Providence Mountains. This requires either rare winds from the east or southeast or, more likely, aeolian reworking of distal Providence Mountain fan sediments by winds from the west, at a rate greater than input from the Mojave River or other western sources. The results indicate that even a small dune field can have a complex origin, either from seasonally varying winds or complex alluvial-fan-dune interaction. Application of K/Rb and K/Ba in K-feldspar as a provenance indicator could be used in many of the world's ergs or sand seas, where dune origins are still not well understood or are controversial. Four examples are given from Africa and the Middle East where such an approach could yield useful new information about dune sand provenance.

Middle Pleistocene infill of Hinkley Valley by Mojave River sediment and associated lake sediment: Depositional architecture and deformation by strike-slip faults

USGS Publications Warehouse

Miller, David; Haddon, Elizabeth; Langenheim, Victoria; Cyr, Andrew J.; Wan, Elmira; Walkup, Laura; Starratt, Scott W.

2018-01-01

Hinkley Valley in the Mojave Desert, near Barstow about 140 km northeast of Los Angeles and midway between Victorville Valley and the Lake Manix basin, contains a thick sedimentary sequence delivered by the Mojave River. Our study of sediment cores drilled in the valley indicates that Hinkley Valley was probably a closed playa basin with stream inflow from four directions prior to Mojave River inflow. The Mojave River deposited thick and laterally extensive clastic wedges originating from the southern valley that rapidly filled much of Hinkley Valley. Sedimentary facies representing braided stream, wetland, delta, and lacustrine depositional environments all are found in the basin fill; in some places, the sequence is greater than 74 m (245 ft) thick. The sediment is dated in part by the presence of the ~631 ka Lava Creek B ash bed low in the section, and thus represents sediment deposition after Victorville basin was overtopped by sediment and before the Manix basin began to be filled. Evidently, upstream Victorville basin filled with sediment by about 650 ka, causing the ancestral Mojave River to spill to the Harper and Hinkley basins, and later to Manix basin.Initial river sediment overran wetland deposits in many places in southern Hinkley Valley, indicating a rapidly encroaching river system. These sediments were succeeded by a widespread lake (“blue” clay) that includes the Lava Creek B ash bed. Above the lake sediment lies a thick section of interlayered stream sediment, delta and nearshore lake sediment, mudflat and/or playa sediment, and minor lake sediment. This stratigraphic architecture is found throughout the valley, and positions of lake sediment layers indicate a successive northward progression in the closed basin. A thin overlapping sequence at the north end of the valley contains evidence for a younger late Pleistocene lake episode. This late lake episode, and bracketing braided stream deposits of the Mojave River, indicate that the river avulsed through the valley, rather than continuing toward Lake Manix, during the late Pleistocene. Two dextral strike-slip fault zones, the Lockhart and the Mt. General, fold and displace the distinctive stratigraphic units, as well as surficial late Pleistocene and Holocene deposits. The sedimentary architecture and the two fault zones provide a framework for evaluating groundwater flow in Hinkley Valley.

Does protection of desert tortoise habitat generate other ecological benefits in the Mojave Desert?

Treesearch

Matthew L. Brooks

2000-01-01

This paper summarizes the ecological effects of fenced habitat protection for the desert tortoise (Gopherus agassizii) at the Desert Tortoise Research Natural Area in the Mojave Desert. The following were higher inside than outside the natural area: (1) annual and perennial plant biomass, cover, diversity and dominance by natives, (2) soil seed...

Holocene landscape response to seasonality of storms in the Mojave Desert

USGS Publications Warehouse

Miller, D.M.; Schmidt, K.M.; Mahan, S.A.; McGeehin, J.P.; Owen, L.A.; Barron, J.A.; Lehmkuhl, F.; Lohrer, R.

2010-01-01

New optically stimulated and radiocarbon ages for alluvial fan and lake deposits in the Mojave Desert are presented, which greatly improves the temporal resolution of surface processes. The new Mojave Desert climate-landscape record is particularly detailed for the late Holocene. Evidence from ephemeral lake deposits and landforms indicates times of sustained stream flow during a wet interval of the latter part of the Medieval Warm Period at ca. AD 1290 and during the Little Ice Age at ca. AD 1650. The former lakes postdate megadroughts of the Medieval Warm Period, whereas the latter match the Maunder Minimum of the Little Ice Age. Periods of alluvial fan aggradation across the Mojave Desert are 14-9 cal ka and 6-3 cal ka. This timing largely correlates to times of increased sea-surface temperatures in the Gulf of California and enhanced warm-season monsoons. This correlation suggests that sustained alluvial fan aggradation may be driven by intense summer-season storms. These data suggest that the close proximity of the Mojave Desert to the Pacific Ocean and the Gulf of California promotes a partitioning of landscape-process responses to climate forcings that vary with seasonality of the dominant storms. Cool-season Pacific frontal storms cause river flow, ephemeral lakes, and fan incision, whereas periods of intense warm-season storms cause hillslope erosion and alluvial fan aggradation. The proposed landscape-process partitioning has important implications for hazard mitigation given that climate change may increase sea-surface temperatures in the Gulf of California, which indirectly could increase future alluvial fan aggradation.

77 FR 14855 - Notice of Availability and Request for Comment on the Draft Environmental Assessment (EA) for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-13

... Reusable Suborbital Rockets at the Mojave Air and Space Port AGENCY: Federal Aviation Administration (FAA... of SpaceShipTwo Reusable Suborbital Rockets at the Mojave Air and Space Port. The Draft EA was... licenses to operate SpaceShipTwo Reusable Suborbital Rockets and WhiteKnightTwo carrier aircraft at the...

A mechanistic modeling and data assimilation framework for Mojave Desert ecohydrology

USGS Publications Warehouse

Ng, Gene-Hua Crystal.; Bedford, David; Miller, David

2014-01-01

This study demonstrates and addresses challenges in coupled ecohydrological modeling in deserts, which arise due to unique plant adaptations, marginal growing conditions, slow net primary production rates, and highly variable rainfall. We consider model uncertainty from both structural and parameter errors and present a mechanistic model for the shrub Larrea tridentata (creosote bush) under conditions found in the Mojave National Preserve in southeastern California (USA). Desert-specific plant and soil features are incorporated into the CLM-CN model by Oleson et al. (2010). We then develop a data assimilation framework using the ensemble Kalman filter (EnKF) to estimate model parameters based on soil moisture and leaf-area index observations. A new implementation procedure, the “multisite loop EnKF,” tackles parameter estimation difficulties found to affect desert ecohydrological applications. Specifically, the procedure iterates through data from various observation sites to alleviate adverse filter impacts from non-Gaussianity in small desert vegetation state values. It also readjusts inconsistent parameters and states through a model spin-up step that accounts for longer dynamical time scales due to infrequent rainfall in deserts. Observation error variance inflation may also be needed to help prevent divergence of estimates from true values. Synthetic test results highlight the importance of adequate observations for reducing model uncertainty, which can be achieved through data quality or quantity.

Presynaptic Neurotoxins: Biochemistry, Molecular Biology, Immunology and Other Exploratory Studies

DTIC Science & Technology

1994-04-01

are involved in activities such as neurotoxicity. myotoxicity, dinmerization, etc.. and nucleic acid sequencing of both cDNAs and genonmic DNA have...other ’critical’ amino acid residues. We can now express both subunits of Mojave toxin in E. coli and are workding to isolate these products in...32 4 LIST OF FIGURES Figure 1. Plasmid subclones of Mojave toxin acidic and basic subu

2002 Water-Table Contours of the Mojave River and the Morongo Ground-Water Basins, San Bernardino County, California

USGS Publications Warehouse

Smith, G.A.; Stamos, C.L.; Predmore, S.K.

2004-01-01

The Mojave River and Morongo ground-water basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water flow systems, and consequently, water availability. During 2002, the U.S. Geological Survey and other agencies made approximately 2,500 water-level measurements in the Mojave River and Morongo ground-water basins. These data document recent conditions and, when compared with previous data, changes in ground-water levels. A water-level contour map was drawn using data from about 660 wells, providing coverage for most of the basins. Twenty-eight hydrographs show long-term (up to 70 years) water-level conditions throughout the basins, and 9 short-term (1997 to 2002) hydrographs show the effects of recharge and discharge along the Mojave River. In addition, a water-level-change map was compiled to compare 2000 and 2002 water levels throughout the basins. In the Mojave River ground-water basin, about 66 percent of the wells had water-level declines of 0.5 ft or more since 2000 and about 27 percent of the wells had water-level declines greater than 5 ft. The only area that had water-level increases greater than 5 ft that were not attributed to fluctuations in nearby pumpage was in the Harper Lake (dry) area where there has been a significant reduction in pumpage during the last decade. In the Morongo ground-water basin, about 36 percent of the wells had water-level declines of 0.5 ft or more and about 10 percent of the wells had water-level declines greater than 5 ft. Water-level increases greater than 5 ft were measured only in the Warren subbasin, where artificial-recharge operations have caused water levels to rise almost 60 ft since 2000.

First results from the Mojave Volatiles Prospector (MVP) Field Campaign, a Lunar Polar Rover Mission Analog

NASA Astrophysics Data System (ADS)

Heldmann, J. L.; Colaprete, A.; Cook, A.; Deans, M. C.; Elphic, R. C.; Lim, D. S. S.; Skok, J. R.

2014-12-01

The Mojave Volatiles Prospector (MVP) project is a science-driven field program with the goal to produce critical knowledge for conducting robotic exploration of the Moon. MVP will feed science, payload, and operational lessons learned to the development of a real-time, short-duration lunar polar volatiles prospecting mission. MVP achieves these goals through a simulated lunar rover mission to investigate the composition and distribution of surface and subsurface volatiles in a natural and a priori unknown environment within the Mojave Desert, improving our understanding of how to find, characterize, and access volatiles on the Moon. The MVP field site is the Mojave Desert, selected for its low, naturally occurring water abundance. The Mojave typically has on the order of 2-6% water, making it a suitable lunar analog for this field test. MVP uses the Near Infrared and Visible Spectrometer Subsystem (NIRVSS), Neutron Spectrometer Subsystem (NSS), and a downward facing GroundCam camera on the KREX-2 rover to investigate the relationship between the distribution of volatiles and soil crust variation. Through this investigation, we mature robotic in situ instruments and concepts of instrument operations, improve ground software tools for real time science, and carry out publishable research on the water cycle and its connection to geomorphology and mineralogy in desert environments. A lunar polar rover mission is unlike prior space missions and requires a new concept of operations. The rover must navigate 3-5 km of terrain and examine multiple sites in in just ~6 days. Operational decisions must be made in real time, requiring constant situational awareness, data analysis and rapid turnaround decision support tools. This presentation will focus on the first science results and operational architecture findings from the MVP field deployment relevant to a lunar polar rover mission.

Paleodischarge of the Mojave River, southwestern U.S.A, investigated with single-pebble measurements of 10Be

USGS Publications Warehouse

Cyr, Andrew J.; Miller, David; Mahan, Shannon

2015-01-01

The paleohydrology of ephemeral stream systems is an important constraint on paleoclimatic conditions in arid environments, but remains difficult to constrain quantitatively. For example, sedimentary records of the size and extent of pluvial lakes in the Mojave Desert have been used as a proxy for Quaternary climate variability. Although the delivery mechanisms of this additional water are still being debated, it is generally agreed that the discharge of the Mojave River, which supplied water for several Pleistocene pluvial lakes along its course, must have been significantly greater during lake high stands. We used the 10Be concentrations of 10 individual quartzite pebbles sourced from the San Bernardino Mountains and collected from a ~25 ka strath terrace of the Mojave River near Barstow, Calif., to test whether pebble ages record the timing of large paleodischarge of the Mojave River. Our exposure ages indicate that periods of discharge large enough to transport pebble-sized sediment occurred at least four times over the past ~240 ky; individual pebble ages cluster into four groups with exposure ages of 24.82 ± 2.52 ka (n=3), 55.79 ± 2.59 ka (n=2), 99.14 ± 6.04 ka (n=4) and 239.9 ± 52.16 ka (n=1). These inferred large discharge events occurred during both glacial and interglacial conditions. We demonstrate that bedload materials provide information about the frequency and duration of transport events in river systems. This approach could be further improved with the addition of additional measurements of one or more cosmogenic nuclides coupled with models of river discharge and pebble transport.

Status of Utah Bats

DTIC Science & Technology

2009-01-27

objectives and scales. Survey effort was lowest in Utah’s West Desert, the Uinta Basin , and extreme southeastern Utah. The Colorado Plateau ecoregion had... Basin shrub steppe, Mojave desert, Wasatch and Uinta montane forest, and Wyoming Basin shrub steppe) as did the physiographic province ( Basin and...shrublands, accounting for 48% of all data, Wasatch and Uinta montane forests 31%, the Great Basin shrub steppe 19%, the Mojave Desert 1.6%, and the

Habitat selection by juvenile Mojave Desert tortoises

USGS Publications Warehouse

Todd, Brian D; Halstead, Brian J.; Chiquoine, Lindsay P.; Peaden, J. Mark; Buhlmann, Kurt A.; Tuberville, Tracey D.; Nafus, Melia G.

2016-01-01

Growing pressure to develop public lands for renewable energy production places several protected species at increased risk of habitat loss. One example is the Mojave desert tortoise (Gopherus agassizii), a species often at the center of conflicts over public land development. For this species and others on public lands, a better understanding of their habitat needs can help minimize negative impacts and facilitate protection or restoration of habitat. We used radio-telemetry to track 46 neonate and juvenile tortoises in the Eastern Mojave Desert, California, USA, to quantify habitat at tortoise locations and paired random points to assess habitat selection. Tortoise locations near burrows were more likely to be under canopy cover and had greater coverage of perennial plants (especially creosote [Larrea tridentata]), more coverage by washes, a greater number of small-mammal burrows, and fewer white bursage (Ambrosia dumosa) than random points. Active tortoise locations away from burrows were closer to washes and perennial plants than were random points. Our results can help planners locate juvenile tortoises and avoid impacts to habitat critical for this life stage. Additionally, our results provide targets for habitat protection and restoration and suggest that diverse and abundant small-mammal populations and the availability of creosote bush are vital for juvenile desert tortoises in the Eastern Mojave Desert.

Evidence for insolation and Pacific forcing of late glacial through Holocene climate in the Central Mojave Desert (Silver Lake, CA)

NASA Astrophysics Data System (ADS)

Kirby, Matthew E.; Knell, Edward J.; Anderson, William T.; Lachniet, Matthew S.; Palermo, Jennifer; Eeg, Holly; Lucero, Ricardo; Murrieta, Rosa; Arevalo, Andrea; Silveira, Emily; Hiner, Christine A.

2015-09-01

Silver Lake is the modern terminal playa of the Mojave River in southern California (USA). As a result, it is well located to record both influences from the winter precipitation dominated San Bernardino Mountains - the source of the Mojave River - and from the late summer to early fall North American monsoon at Silver Lake. Here, we present various physical, chemical and biological data from a new radiocarbon-dated, 8.2 m sediment core taken from Silver Lake that spans modern through 14.8 cal ka BP. Texturally, the core varies between sandy clay, clayey sand, and sand-silt-clay, often with abrupt sedimentological transitions. These grain-size changes are used to divide the core into six lake status intervals over the past 14.8 cal ka BP. Notable intervals include a dry Younger Dryas chronozone, a wet early Holocene terminating 7.8 - 7.4 cal ka BP, a distinct mid-Holocene arid interval, and a late Holocene return to ephemeral lake conditions. A comparison to potential climatic forcings implicates a combination of changing summer - winter insolation and tropical and N Pacific sea-surface temperature dynamics as the primary drivers of Holocene climate in the central Mojave Desert.

Evolutionary hotspots in the Mojave Desert

USGS Publications Warehouse

Vandergast, Amy G.; Inman, Richard D.; Barr, Kelly R.; Nussear, Kenneth E.; Esque, Todd C.; Hathaway, Stacie A.; Wood, Dustin A.; Medica, Philip A.; Breinholt, Jesse W.; Stephen, Catherine L.; Gottscho, Andrew D.; Marks, Sharyn B.; Jennings, W. Bryan; Fisher, Robert N.

2013-01-01

Genetic diversity within species provides the raw material for adaptation and evolution. Just as regions of high species diversity are conservation targets, identifying regions containing high genetic diversity and divergence within and among populations may be important to protect future evolutionary potential. When multiple co-distributed species show spatial overlap in high genetic diversity and divergence, these regions can be considered evolutionary hotspots. We mapped spatial population genetic structure for 17 animal species across the Mojave Desert, USA. We analyzed these in concurrence and located 10 regions of high genetic diversity, divergence or both among species. These were mainly concentrated along the western and southern boundaries where ecotones between mountain, grassland and desert habitat are prevalent, and along the Colorado River. We evaluated the extent to which these hotspots overlapped protected lands and utility-scale renewable energy development projects of the Bureau of Land Management. While 30–40% of the total hotspot area was categorized as protected, between 3–7% overlapped with proposed renewable energy project footprints, and up to 17% overlapped with project footprints combined with transmission corridors. Overlap of evolutionary hotspots with renewable energy development mainly occurred in 6 of the 10 identified hotspots. Resulting GIS-based maps can be incorporated into ongoing landscape planning efforts and highlight specific regions where further investigation of impacts to population persistence and genetic connectivity may be warranted.

Year 1 Field Work Report: Utah Bat Monitoring Protocol

DTIC Science & Technology

2010-01-28

Plateau shrublands, Great Basin shrub steppe, Wasatch and Uinta montane forests, Mojave Desert and Wyoming Basin shrub steppe. A total 65, 20 x 20 km... Basin shrub steppe, Wasatch and Uinta montane forests) each harbored 20 sampling cells, while the limited size of the Mojave Desert and Wyoming Basin ...Wasatch and Uinta montane forest and Wyoming Basin shrub steppe). Site # A unique identifier between 1 and 20 within each ecoregion. UTM The

Environmental effects of solar-thermal power systems. Systematic status of the Mojave ground squirrel, Spermophilus mohavensis (subgenus Xerospermophilus)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hafner, D.J.; Yates, T.L.

1982-06-01

The Mojave ground squirrel, Spermophilus mohavensis, is listed as a rare species by The California Fish and Game Commission. Its well-being has emerged as an environmental concern associated with deployment of solar thermal power systems in western parts of the Motave Desert. The more common round-tailed ground squirrel, Spermophilus tereticaudus, also occurs in the Mojave Desert, and this species closely resembles S. mohavensis. The systematic status of the sibling species was investigated using allozymic and chromosomal data. Karyotypically, the two species differ in diploid number while they share a level of genic similarity reported for other mammalian semispecies. Hybridization wasmore » detected only at a single disturbed site, while allelic introgression was confined to an estimated 60 km reach. The two taxa are retained as full biological species.« less

Ozone Transport Aloft Drives Surface Ozone Maxima Across the Mojave Desert

NASA Astrophysics Data System (ADS)

VanCuren, R. A.

2014-12-01

A persistent layer of polluted air in the lower free troposphere over the Mojave Desert (California and Nevada) drives spring and summer surface ozone maxima as deep afternoon mixing delivers ozone and ozone precursors to surface measurement sites 200 km or more downwind of the mountains that separate the deserts from the heavily populated coastal areas of California. Pollutants in this elevated layer derive from California source regions (the Los Angeles megacity region and the intensive agricultural region of the San Joaquin Valley), and from long-range transport from Asia. Recognition of this poorly studied persistent layer explains and expands the significance of previously published reports of ozone and other pollutants observed in and over the Mojave Desert, resolves an apparent paradox in the timing of ozone peaks due to transport from the upwind basins, and provides a new perspective on the long-range downwind impacts of megacity pollution plumes.

Mojave remote sensing field experiment

NASA Technical Reports Server (NTRS)

Arvidson, Raymond E.; Petroy, S. B.; Plaut, J. J.; Shepard, Michael K.; Evans, D.; Farr, T.; Greeley, Ronald; Gaddis, L.; Lancaster, N.

1991-01-01

The Mojave Remote Sensing Field Experiment (MFE), conducted in June 1988, involved acquisition of Thermal Infrared Multispectral Scanner (TIMS); C, L, and P-band polarimetric radar (AIRSAR) data; and simultaneous field observations at the Pisgah and Cima volcanic fields, and Lavic and Silver Lake Playas, Mojave Desert, California. A LANDSAT Thematic Mapper (TM) scene is also included in the MFE archive. TM-based reflectance and TIMS-based emissivity surface spectra were extracted for selected surfaces. Radiative transfer procedures were used to model the atmosphere and surface simultaneously, with the constraint that the spectra must be consistent with field-based spectral observations. AIRSAR data were calibrated to backscatter cross sections using corner reflectors deployed at target sites. Analyses of MFE data focus on extraction of reflectance, emissivity, and cross section for lava flows of various ages and degradation states. Results have relevance for the evolution of volcanic plains on Venus and Mars.

The western pond turtle (Clemmys marmorata) in the Mojave River, California, USA: Highly adapted survivor or tenuous relict?

USGS Publications Warehouse

Lovich, J.; Meyer, K.

2002-01-01

Aspects of the ecology of populations of the western pond turtle Clemmys marmorata were investigated in the Mojave River of the central Mojave Desert, California, U.S.A. One population occupied man-made ponds and the other occurred in natural ponds in the flood plain of the Mojave River. Both habitats are severely degraded as a result of ground water depletion from human activities along the river and one is infested with the exotic shrub saltcedar Tamarix ramosissima. Mean female carapace length (CL) was significantly greater (14.4 cm) than that of males (13.7 cm). Live juveniles were not detected during the period of study. Shelled eggs were visible in X-radiographs from 26 May to 14 July. Mean clutch size was 4.46 and ranged from 3 to 6 eggs. Clutch size did not vary between 1998 and 1999 but was significantly correlated with CL for both years combined, increasing at the rate of 0.548 eggs/cm CL. Gravid female CL ranged from 13.3-16.0 cm. Some females nested in both years. Mean X-ray egg width (21.8 mm) was not significantly correlated with CL or clutch size. X-ray egg width differed more among clutches than within, whether including CL as a co-variate or not. Nesting migrations occurred from 6 June to 8 July with minimum round trip distances ranging from 17.5-585 m with a mean of 195 m. Mean estimated time of departure as measured at the drift fence was 18:13. Most females returned to the ponds in the early morning. Nesting migrations required females to be out of the water for estimated periods of 0.83 to 86 h. The destination of nesting females was typically fluvial sand bars in the channel of the dry riverbed. Overall, the ecology of C. marmorata in the Mojave River is very similar to that reported for populations in less severe habitats along the west coast of the United States. Notable exceptions include long nesting migrations to sandbars in the dry river channel, a possible result of human modifications to the environment, and an apparent lack of terrestrial overwintering behaviour in Mojave River populations. The general similarity of desert and coastal populations is possibly a reflection of their recent geographic separation. Overall, populations in the Mojave River exhibit few obvious adaptations to living in the desert and are considered to be tenuous relicts of the Pleistocene. The small size and tenuous status of these populations suggests that immediate conservation action is needed, including establishment of satellite populations as a hedge against extirpation.

Environmental Assessment for the Air Force Research Laboratory Security Fence Project, Edwards Air Force Base, California

DTIC Science & Technology

2012-11-26

Pleistocene/Early-Holocene Prehistory (12,000 to 7,000 BP). The Lake Mojave Period in the southwestern Great Basin comprises a regional manifestation...adaptive patterns with focal exploitation of such habitats (Tetra Tech 2010). Middle-Holocene Prehistory (8,000 to 4,000 BP). Succeeding Lake Mojave in the...Security Fence at Edwards Air Force Base, California Late Holocene Prehistory (4,000 to Contact). With return to more “favorable” environmental

Effects of anthropogenic developments on common raven nesting biology in the West Mojave Desert.

PubMed

Kristan, William B; Boarman, William I

2007-09-01

Subsidized predators may affect prey abundance, distribution, and demography. Common Ravens (Corvus corax) are anthropogenically subsidized throughout their range and, in the Mojave Desert, have increased in number dramatically over the last 3-4 decades. Human-provided food resources are thought to be important drivers of raven population growth, but human developments add other features as well, such as nesting platforms. From 1996 to 2000, we examined the nesting ecology of ravens in the Mojave Desert, relative to anthropogenic developrhent. Ravens nested disproportionately near point sources of food and water subsidies (such as towns, landfills, and ponds) but not near roads (sources of road-killed carrion), even though both sources of subsidy enhanced fledging success. Initiation of breeding activity was more likely when a nest from the previous year was present at the start of a breeding season but was not affected by access to food. The relative effect of environmental modifications on fledging success varied from year to year, but the effect of access to human-provided resources was comparatively consistent, suggesting that humans provide consistently high-quality breeding habitat for ravens. Anthropogenic land cover types in the desert are expected to promote raven population growth and to allow ravens to occupy parts of the desert that otherwise would not support them. Predatory impacts of ravens in the Mojave Desert can therefore be considered indirect effects of anthropogenic development.

Land-cover trends in the Mojave basin and range ecoregion

USGS Publications Warehouse

Sleeter, Benjamin M.; Raumann, Christian G.

2006-01-01

The U.S. Geological Survey's Land-Cover Trends Project aims to estimate the rates of contemporary land-cover change within the conterminous United States between 1972 and 2000. A random sampling approach was used to select a representative sample of 10-km by 10-km sample blocks and to estimate change within +/- 1 percent at an 85-percent confidence interval. Landsat Multispectral Scanner, Thematic Mapper, and Enhanced Thematic Mapper Plus data were used, and each 60-m pixel was assigned to one of 11 distinct land-cover classes based upon a modified Anderson classification system. Upon completion of land-cover change mapping for five dates, land-cover change statistics were generated and analyzed. This paper presents estimates for the Mojave Basin and Range ecoregion located in the southwestern United States. Our research suggests land-cover change within the Mojave to be relatively rare and highly localized. The primary shift in land cover is unidirectional, with natural desert grass/shrubland being converted to development. We estimate that more than 1,300 km2 have been converted since 1973 and that the conversion is being largely driven by economic and recreational opportunities provided by the Mojave ecoregion. The time interval with the highest rate of change was 1986 to 1992, in which the rate was 0.21 percent (321.9 km2) per year total change.

Comparative phylogeography reveals deep lineages and regional evolutionary hotspots in the Mojave and Sonoran Deserts

USGS Publications Warehouse

Wood, Dustin A.; Vandergast, Amy G.; Barr, Kelly R.; Inman, Richard D.; Esque, Todd C.; Nussear, Kenneth E.; Fisher, Robert N.

2013-01-01

Aim: We explored lineage diversification within desert-dwelling fauna. Our goals were (1) to determine whether phylogenetic lineages and population expansions were consistent with younger Pleistocene climate fluctuation hypotheses or much older events predicted by pre-Pleistocene vicariance hypotheses, (2) to assess concordance in spatial patterns of genetic divergence and diversity among species and (3) to identify regional evolutionary hotspots of divergence and diversity and assess their conservation status. Location: Mojave, Colorado, and Sonoran Deserts, USA. Methods: We analysed previously published gene sequence data for twelve species. We used Bayesian gene tree methods to estimate lineages and divergence times. Within each lineage, we tested for population expansion and age of expansion using coalescent approaches. We mapped interpopulation genetic divergence and intra-population genetic diversity in a GIS to identify hotspots of highest genetic divergence and diversity and to assess whether protected lands overlapped with evolutionary hotspots. Results: In seven of the 12 species, lineage divergence substantially predated the Pleistocene. Historical population expansion was found in eight species, but expansion events postdated the Last Glacial Maximum (LGM) in only four. For all species assessed, six hotspots of high genetic divergence and diversity were concentrated in the Colorado Desert, along the Colorado River and in the Mojave/Sonoran ecotone. At least some proportion of the land within each recovered hotspot was categorized as protected, yet four of the six also overlapped with major areas of human development. Main conclusions: Most of the species studied here diversified into distinct Mojave and Sonoran lineages prior to the LGM – supporting older diversification hypotheses. Several evolutionary hotspots were recovered but are not strategically paired with areas of protected land. Long-term preservation of species-level biodiversity would entail selecting areas for protection in Mojave and Sonoran Deserts to retain divergent genetic diversity and ensure connectedness across environmental gradients.

Transport aloft drives peak ozone in the Mojave Desert

NASA Astrophysics Data System (ADS)

VanCuren, Richard

2015-05-01

Transport of anthropogenic pollution eastward out of the Los Angeles megacity region in California has been periodically observed to reach the Colorado River and the Colorado Plateau region beyond. In the 1980s, anthropogenic halocarbon tracers measured in and near the Las Angeles urban area and at a mountain-top site near the Colorado River, 400 km downwind, were shown to have a correlated seven-day cycle explainable by transport from the urban area with a time lag of 1-2 days. Recent short term springtime intensive studies using aircraft observations and regional modeling of long range transport of ozone from the Southern California megacity region showed frequent and persistent ozone impacts at surface sites across the Colorado Plateau and Southern Rocky Mountain region, at distances up to 1500 km, also with time lags of 1-2 days. However, the timing of ozone peaks at low altitude monitoring sites within the Mojave Desert, at distances from 100 to 400 km from the South Coast and San Joaquin Valley ozone source regions, does not show the expected time-lag behavior seen in the larger transport studies. This discrepancy is explained by recognizing ozone transport across the Mojave Desert to occur in a persistent layer of polluted air in the lower free troposphere with a base level at approximately 1 km MSL. This layer impacts elevated downwind sites directly, but only influences low altitude surface ozone maxima through deep afternoon mixing. Pollutants in this elevated layer derive from California source regions (the Los Angeles megacity region and the intensive agricultural region of the San Joaquin Valley), from long-range transport from Asia, and stratospheric down-mixing. Recognition of the role of afternoon mixing during spring and summer over the Mojave explains and expands the significance of previously published reports of ozone and other pollutants observed in and over the Mojave Desert, and resolves an apparent paradox in the timing of ozone peaks due to short-range and long-range transport from the upwind basins.

Solar Energy Development on DoD Installations in the Mojave & Colorado Deserts

DTIC Science & Technology

2011-11-30

roof mount • Acreage: – ~6.2 million acres on 9 installations – 250,000 acres with some level of suitability for solar – 120,000 acres are estimated...technologies: thin - film and crystalline PV x fixed and single-axis tracking; trough; dish/Stirling engine. • 2 ownership structures (MILCON and 3rd party...1icfi.com | Solar Energy Development on DoD Installations in the Mojave & Colorado Deserts Bob Kwartin ICF International November 30, 2011 Report

PCR primers for microsatellite loci in the desert tortoise (Gopherus agassizii, Testudinidae)

USGS Publications Warehouse

Edwards, T.; Goldberg, C.S.; Kaplan, M.E.; Schwalbe, C.R.; Swann, D.E.

2003-01-01

The desert tortoise, Gopherus agassizii, is a threatened species native to the North American desert southwest and is recognized as having distinct Mojave and Sonoran populations. We identified six polymorphic microsatellite loci in the desert tortoise. All six loci were polymorphic in Sonoran samples. Five of the loci were variable in Mojave samples with varying degrees of amplification success. Two of the loci exhibited low allelic variation (2-3 alleles) while four were highly variable (8-27 alleles).

Ground-water recharge from small intermittent streams in the western Mojave Desert, California: Chapter G in Ground-water recharge in the arid and semiarid southwestern United States (Professional Paper 1703)

USGS Publications Warehouse

Izbicki, John A.; Johnson, Russell U.; Kulongoski, Justin T.; Predmore, Steven; Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.

2007-01-01

Population growth has impacted ground-water resources in the western Mojave Desert, where declining water levels suggest that recharge rates have not kept pace with withdrawals. Recharge from the Mojave River, the largest hydrographic feature in the study area, is relatively well characterized. In contrast, recharge from numerous smaller streams that convey runoff from the bounding mountains is poorly characterized. The current study examined four representative streams to assess recharge from these intermittent sources. Hydraulic, thermal, geomorphic, chemical, and isotopic data were used to study recharge processes, from streamflow generation and infiltration to percolation through the unsaturated zone. Ground-water movement away from recharge areas was also assessed.Infiltration in amounts sufficient to have a measurable effect on subsurface temperature profiles did not occur in every year in instrumented study reaches. In addition to streamflow availability, results showed the importance of sediment texture in controlling infiltration and eventual recharge. Infiltration amounts of about 0.7 meters per year were an approximate threshold for the occurrence of ground-water recharge. Estimated travel times through the thick unsaturated zones underlying channels reached several hundred years. Recharging fluxes were influenced by stratigraphic complexity and depositional dynamics. Because of channel meandering, not all water that penetrates beneath the root zone can be assumed to become recharge on active alluvial fans.Away from study washes, elevated chloride concentrations and highly negative water potentials beneath the root zone indicated negligible recharge from direct infiltration of precipitation under current climatic conditions. In upstream portions of washes, generally low subsurface chloride concentrations and near-zero water potentials indicated downward movement of water toward the water table, driven primarily by gravity. Recharging conditions did not extend to the distal ends of all washes. Where urbanization had concentrated spatially distributed runoff into a small number of fixed channels, enhanced infiltration induced recharging conditions, mobilizing accumulated chloride.Estimated amounts of ground-water recharge from the studied reaches were small. Extrapolating on the basis of drainage areas, the estimated aggregate recharge from small intermittent streams is minor compared to recharge from the Mojave River. Recharge is largely controlled by streamflow availability, which primarily reflects precipitation patterns. Precipitation in the Mojave Desert is strongly controlled by topography. Cool moist air masses from the Pacific Ocean are mostly blocked from entering the desert by the high mountains bordering its southern edge. Storms do, however, readily enter the region through Cajon Pass. These storms generate flow in the Mojave River that often reaches Afton Canyon, more than 150 kilometers downstream. The isotopic composition of ground water reflects the localization of recharge beneath the Mojave River. Similar processes occur near San Gorgonio Pass, 75 kilometers southeast from Cajon Pass along the bounding San Andreas Fault.

Conservation planning for offsetting the impacts of development: a case study of biodiversity and renewable energy in the Mojave Desert

USGS Publications Warehouse

Kreitler, Jason R.; Schloss, Carrie A.; Soong, Oliver; Lee Hannah,; Davis, Frank W.

2015-01-01

Balancing society’s competing needs of development and conservation requires careful consideration of tradeoffs. Renewable energy development and biodiversity conservation are often considered beneficial environmental goals. The direct footprint and disturbance of renewable energy, however, can displace species’ habitat and negatively impact populations and natural communities if sited without ecological consideration. Offsets have emerged as a potentially useful tool to mitigate residual impacts after trying to avoid, minimize, or restore affected sites. Yet the problem of efficiently designing a set of offset sites becomes increasingly complex where many species or many sites are involved. Spatial conservation prioritization tools are designed to handle this problem, but have seen little application to offset siting and analysis. To address this need we designed an offset siting support tool for the Desert Renewable Energy Conservation Plan (DRECP) of California, and present a case study of hypothetical impacts from solar development in the Western Mojave subsection. We compare two offset scenarios designed to mitigate a hypothetical 15,331 ha derived from proposed utility-scale solar energy development (USSED) projects. The first scenario prioritizes offsets based precisely on impacted features, while the second scenario offsets impacts to maximize biodiversity conservation gains in the region. The two methods only agree on 28% of their prioritized sites and differ in meeting species-specific offset goals. Differences between the two scenarios highlight the importance of clearly specifying choices and priorities for offset siting and mitigation in general. Similarly, the effects of background climate and land use change may lessen the durability or effectiveness of offsets if not considered. Our offset siting support tool was designed specifically for the DRECP area, but with minor code modification could work well in other offset analyses, and could provide continuing support for a potentially innovative mitigation solution to environmental impacts.

Conservation Planning for Offsetting the Impacts of Development: A Case Study of Biodiversity and Renewable Energy in the Mojave Desert.

PubMed

Kreitler, Jason; Schloss, Carrie A; Soong, Oliver; Hannah, Lee; Davis, Frank W

2015-01-01

Balancing society's competing needs of development and conservation requires careful consideration of tradeoffs. Renewable energy development and biodiversity conservation are often considered beneficial environmental goals. The direct footprint and disturbance of renewable energy, however, can displace species' habitat and negatively impact populations and natural communities if sited without ecological consideration. Offsets have emerged as a potentially useful tool to mitigate residual impacts after trying to avoid, minimize, or restore affected sites. Yet the problem of efficiently designing a set of offset sites becomes increasingly complex where many species or many sites are involved. Spatial conservation prioritization tools are designed to handle this problem, but have seen little application to offset siting and analysis. To address this need we designed an offset siting support tool for the Desert Renewable Energy Conservation Plan (DRECP) of California, and present a case study of hypothetical impacts from solar development in the Western Mojave subsection. We compare two offset scenarios designed to mitigate a hypothetical 15,331 ha derived from proposed utility-scale solar energy development (USSED) projects. The first scenario prioritizes offsets based precisely on impacted features, while the second scenario offsets impacts to maximize biodiversity conservation gains in the region. The two methods only agree on 28% of their prioritized sites and differ in meeting species-specific offset goals. Differences between the two scenarios highlight the importance of clearly specifying choices and priorities for offset siting and mitigation in general. Similarly, the effects of background climate and land use change may lessen the durability or effectiveness of offsets if not considered. Our offset siting support tool was designed specifically for the DRECP area, but with minor code modification could work well in other offset analyses, and could provide continuing support for a potentially innovative mitigation solution to environmental impacts.

Conservation Planning for Offsetting the Impacts of Development: A Case Study of Biodiversity and Renewable Energy in the Mojave Desert

PubMed Central

Kreitler, Jason; Schloss, Carrie A.; Soong, Oliver; Hannah, Lee; Davis, Frank W.

2015-01-01

Balancing society’s competing needs of development and conservation requires careful consideration of tradeoffs. Renewable energy development and biodiversity conservation are often considered beneficial environmental goals. The direct footprint and disturbance of renewable energy, however, can displace species’ habitat and negatively impact populations and natural communities if sited without ecological consideration. Offsets have emerged as a potentially useful tool to mitigate residual impacts after trying to avoid, minimize, or restore affected sites. Yet the problem of efficiently designing a set of offset sites becomes increasingly complex where many species or many sites are involved. Spatial conservation prioritization tools are designed to handle this problem, but have seen little application to offset siting and analysis. To address this need we designed an offset siting support tool for the Desert Renewable Energy Conservation Plan (DRECP) of California, and present a case study of hypothetical impacts from solar development in the Western Mojave subsection. We compare two offset scenarios designed to mitigate a hypothetical 15,331 ha derived from proposed utility-scale solar energy development (USSED) projects. The first scenario prioritizes offsets based precisely on impacted features, while the second scenario offsets impacts to maximize biodiversity conservation gains in the region. The two methods only agree on 28% of their prioritized sites and differ in meeting species-specific offset goals. Differences between the two scenarios highlight the importance of clearly specifying choices and priorities for offset siting and mitigation in general. Similarly, the effects of background climate and land use change may lessen the durability or effectiveness of offsets if not considered. Our offset siting support tool was designed specifically for the DRECP area, but with minor code modification could work well in other offset analyses, and could provide continuing support for a potentially innovative mitigation solution to environmental impacts. PMID:26529595

Recent trends of desert tortoise populations in the Mojave Desert

USGS Publications Warehouse

Corn, Paul Stephen

1994-01-01

The desert tortoise, Gopherus agassizii (Cooper), was listed as threatened in the Mojave Desert in 1990. Important factors for the listing were severe recent mortality in tortoise populations and a general decline throughout this century. Recent trends in tortoise populations were examined by plotting total captures of adult and juvenile tortoises from 2.6-km2 study plots, rather than by mark-and-recapture population estimates. Changes in relative abundance of tortoises were greatest among large tortoises in the western Mojave Desert, which may reflect high levels of human disturbance, and among small tortoises, which may reflect either lower ability of searches to detect small tortoises or greater mortality of tortoises during drought conditions in 1986-90, or both factors. Further collection of data on population trends is needed, particularly in years with higher-than-average precipitation. Retention of the threatened status of the tortoise is a conservative strategy for the conservation of natural resources but should be reassessed when additional data are available.

Discrimination of active and inactive sand from remote sensing - Kelso dunes, Mojave Desert, California

NASA Technical Reports Server (NTRS)

Paisley, Elizabeth C. I.; Lancaster, Nicholas; Gaddis, Lisa R.; Greeley, Ronald

1991-01-01

Landsat TM images, field data, and laboratoray reflectance spectra were examined for the Kelso dunes, Mojave Desert, California to assess the use of visible and near-infrared (VNIR) remote sensing data to discriminate aeolian sand populations on the basis of spectral brightness. Results show that areas of inactive sand have a larger percentage of dark, fine-grained materials compared to those composed of active sand, which contain less dark fines and a higher percentage of quartz sand-size grains. Both areas are spectrally distinct in the VNIR, suggesting that VNIR spectral data can be used to discriminate active and inactive sand populations in the Mojave Desert. Analysis of laboratory spectra was complicated by the presence of magnetite in the active sands, which decreases their laboratory reflectance values to those of inactive sands. For this application, comparison of TM and laboratory spectra suggests that less than 35 percent vegetation cover does not influence the TM spectra.

Surficial and bedrock geologic map database of the Kelso 7.5 Minute quadrangle, San Bernardino County, California

USGS Publications Warehouse

Bedford, David R.

2003-01-01

This geologic map database describes geologic materials for the Kelso 7.5 Minute Quadrangle, San Bernardino County, California. The area lies in eastern Mojave Desert of California, within the Mojave National Preserve (a unit of the National Parks system). Geologic deposits in the area consist of Proterozoic metamorphic rocks, Cambrian-Neoproterozoic sedimentary rocks, Mesozoic plutonic and hypabyssal rocks, Tertiary basin fill, and Quaternary surficial deposits. Bedrock deposits are described by composition, texture, and stratigraphic relationships. Quaternary surficial deposits are classified into soil-geomorphic surfaces based on soil characteristics, inset relationships, and geomorphic expression. The surficial geology presented in this report is especially useful to understand, and extrapolate, physical properties that influence surface conditions, and surface- and soil-water dynamics. Physical characteristics such as pavement development, soil horizonation, and hydraulic characteristics have shown to be some of the primary drivers of ecologic dynamics, including recovery of those ecosystems to anthropogenic disturbance, in the eastern Mojave Desert and other arid and semi-arid environments.

Taming Data to Make Decisions: Using a Spatial Fuzzy Logic Decision Support Framework to Inform Conservation and Land Use Planning

NASA Astrophysics Data System (ADS)

Sheehan, T.; Baker, B.; Degagne, R. S.

2015-12-01

With the abundance of data sources, analytical methods, and computer models, land managers are faced with the overwhelming task of making sense of a profusion of data of wildly different types. Luckily, fuzzy logic provides a method to work with different types of data using language-based propositions such as "the landscape is undisturbed," and a simple set of logic constructs. Just as many surveys allow different levels of agreement with a proposition, fuzzy logic allows values reflecting different levels of truth for a proposition. Truth levels fall within a continuum ranging from Fully True to Fully False. Hence a fuzzy logic model produces continuous results. The Environmental Evaluation Modeling System (EEMS) is a platform-independent, tree-based, fuzzy logic modeling framework. An EEMS model provides a transparent definition of an evaluation model and is commonly developed as a collaborative effort among managers, scientists, and GIS experts. Managers specify a set of evaluative propositions used to characterize the landscape. Scientists, working with managers, formulate functions that convert raw data values into truth values for the propositions and produce a logic tree to combine results into a single metric used to guide decisions. Managers, scientists, and GIS experts then work together to implement and iteratively tune the logic model and produce final results. We present examples of two successful EEMS projects that provided managers with map-based results suitable for guiding decisions: sensitivity and climate change exposure in Utah and the Colorado Plateau modeled for the Bureau of Land Management; and terrestrial ecological intactness in the Mojave and Sonoran region of southern California modeled for the Desert Renewable Energy Conservation Plan.

Modeling Habitat of the Desert Tortoise (Gopherus agassizii) in the Mojave and Parts of the Sonoran Deserts of California, Nevada, Utah, and Arizona

USGS Publications Warehouse

Nussear, Kenneth E.; Esque, Todd C.; Inman, Richard D.; Gass, Leila; Thomas, Kathryn A.; Wallace, Cynthia S.A.; Blainey, Joan B.; Miller, David M.; Webb, Robert H.

2009-01-01

Habitat modeling is an important tool used to simulate the potential distribution of a species for a variety of basic and applied questions. The desert tortoise (Gopherus agassizii) is a federally listed threatened species in the Mojave Desert and parts of the Sonoran Desert of California, Nevada, Utah, and Arizona. Land managers in this region require reliable information about the potential distribution of desert tortoise habitat to plan conservation efforts, guide monitoring activities, monitor changes in the amount and quality of habitat available, minimize and mitigate disturbances, and ultimately to assess the status of the tortoise and its habitat toward recovery of the species. By applying information from the literature and our knowledge or assumptions of environmental variables that could potentially explain variability in the quality of desert tortoise habitat, we developed a quantitative habitat model for the desert tortoise using an extensive set of field-collected presence data. Sixteen environmental data layers were converted into a grid covering the study area and merged with the desert tortoise presence data that we gathered for input into the Maxent habitat-modeling algorithm. This model provides output of the statistical probability of habitat potential that can be used to map potential areas of desert tortoise habitat. This type of analysis, while robust in its predictions of habitat, does not account for anthropogenic changes that may have altered habitat with relatively high potential into areas with lower potential.

Effects of anthropogenic developments on common Raven nesting biology in the west Mojave Desert

USGS Publications Warehouse

Kristan, W. B.; Boarman, W.I.

2007-01-01

Subsidized predators may affect prey abundance, distribution, and demography. Common Ravens (Corvus corax) are anthropogenically subsidized throughout their range and, in the Mojave Desert, have increased in number dramatically over the last 3-4 decades. Human-provided food resources are thought to be important drivers of raven population growth, but human developments add other features as well, such as nesting platforms. From 1996 to 2000, we examined the nesting ecology of ravens in the Mojave Desert, relative to anthropogenic development. Ravens nested disproportionately near point sources of food and water subsidies (such as towns, landfills, and ponds) but not near roads (sources of road-killed carrion), even though both sources of subsidy enhanced fledging success. Initiation of breeding activity was more likely when a nest from the previous year was present at the start of a breeding season but was not affected by access to food. The relative effect of environmental modifications on fledging success varied from year to year, but the effect of access to humanprovided resources was comparatively consistent, suggesting that humans provide consistently high-quality breeding habitat for ravens. Anthropogenic land cover types in the desert are expected to promote raven population growth and to allow ravens to occupy parts of the desert that otherwise would not support them. Predatory impacts of ravens in the Mojave Desert can therefore be considered indirect effects of anthropogenic development. ?? 2007 by the Ecological Society of America.

SpaceX Dragon Parachute Test

NASA Image and Video Library

2018-03-04

SpaceX performed its fourteenth overall parachute test supporting Crew Dragon development. This most recent exercise was the first of several planned parachute system qualification tests ahead of the spacecraft’s first crewed flight and resulted in the successful touchdown of Crew Dragon’s parachute system. During this test, a C-130 aircraft transported the parachute test vehicle, designed to achieve the maximum speeds that Crew Dragon could experience on re-entry, over the Mojave Desert in Southern California and dropped the vehicle from an altitude of 25,000 feet. The test demonstrated an off-nominal situation, deploying only one of the two drogue chutes and intentionally skipping a reefing stage on one of the four main parachutes, proving a safe landing in such a contingency scenario.

Groundwater quality in the Borrego Valley, Central Desert, and Low-Use Basins of the Mojave and Sonoran Deserts, California

USGS Publications Warehouse

Parsons, Mary C.; Belitz, Kenneth

2014-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s untreated groundwater quality and increases public access to groundwater-quality information. Selected groundwater basins in the Borrego Valley, Central Desert, and Low-Use Basins of the Mojave and Sonoran Deserts constitute one of the study units being evaluated.

Scaled Composites' Proteus aircraft with an F/A-18 Hornet and a Beechcraft KingAir from NASA's Dryden Flight Research Center during a low-level flyby at Mojave Airport in Southern California.

NASA Image and Video Library

2003-04-03

Scaled Composites' Proteus aircraft with an F/A-18 Hornet and a Beechcraft KingAir from NASA's Dryden Flight Research Center during a low-level flyby at Mojave Airport in Southern California. The unique tandem-wing Proteus was the testbed for a series of UAV collision-avoidance flight demonstrations. An Amphitech 35GHz radar unit installed below Proteus' nose was the primary sensor for the Detect, See and Avoid tests.

Scaled Composites' Proteus aircraft and an F/A-18 Hornet from NASA's Dryden Flight Research Center at Mojave Airport in Southern California.

NASA Image and Video Library

2003-04-03

Scaled Composites' Proteus aircraft and an F/A-18 Hornet from NASA's Dryden Flight Research Center at Mojave Airport in Southern California. The unique tandem-wing Proteus was the testbed for a series of UAV collision-avoidance flight demonstrations. An Amphitech 35GHz radar unit installed below Proteus' nose was the primary sensor for the Detect, See and Avoid tests. NASA Dryden's F/A-18 Hornet was one of many different aircraft used in the tests.

Ventifact Formation in the Mojave Desert: Field Analogs for Martian Processes

NASA Technical Reports Server (NTRS)

Laity, J. E.; Bridges, N. T.; Boyle, T. K.

2001-01-01

Two field studies in the Mojave Desert, California, shed light on processes of ventifact formation. The field sites are located on a ridge at Little Cowhole Mountain, which lies approximately 12 km south of Baker, and on an unnamed ridge situated along the northern boundary of the Mojave River Sink (Rasor Road site). The rocks at Little Cowhole Mountain are a blue-grey marble/dolomite, whereas those at Rasor Road are Miocene volcanic rocks (basalt). At both sites the abrasive agent is a fine-grained aeolian sand which was probably derived largely from the Mojave River. There are minimal modem inputs of sand to either site: abrasion occurs as a result of unique climatic and topographic conditions which allow pre-existing sand to be recycled from one aspect of the ridge to the other. Climatic conditions are well suited for ventifact formation. Owing, to the dry climate (marked by low average relative humidity, infrequent dew, and low annual rainfall), rates of chemical weathering are low. Where resurfacing of the rocks by sand abrasion proceeds at a rate greater than weathering, the ventifacts are considered "active." Active ventifacts are found atop and straddling the ridge crests, in the zone of maximum wind velocity and sediment supply. Inactive ventifacts occur where modem weathering Processes exceed abrasion rates; principally on the basal two-thirds of the hillslope, where wind velocity and sediment supply are lower. At intermediate locations between the slope base and crest, ventifacts are either active or inactive, depending on local conditions. The presence of relict ventifacts at the study sites, as well as elsewhere in the eastern Mojave Desert, suggests that the conditions for venti fact formation must have been more intense and extensive in the past. Together, the studies illustrate that the processes that interact to form ventifacts are highly complex, and must be studied at many scales. Small-scale effects, such as local topography, plant cover, or even the spatial distribution of boulders, strongly influence the formation of each individual ventifact. Mesoscale effects (hillslope form, total availability of sediment, seasonality of winds, etc.) determine the distribution of overall erosional energy and the location of active and relict forms.

Imaging Radar in the Mojave Desert-Death Valley Region

NASA Technical Reports Server (NTRS)

Farr, Tom G.

2001-01-01

The Mojave Desert-Death Valley region has had a long history as a test bed for remote sensing techniques. Along with visible-near infrared and thermal IR sensors, imaging radars have flown and orbited over the area since the 1970's, yielding new insights into the geologic applications of these technologies. More recently, radar interferometry has been used to derive digital topographic maps of the area, supplementing the USGS 7.5' digital quadrangles currently available for nearly the entire area. As for their shorter-wavelength brethren, imaging radars were tested early in their civilian history in the Mojave Desert-Death Valley region because it contains a variety of surface types in a small area without the confounding effects of vegetation. The earliest imaging radars to be flown over the region included military tests of short-wavelength (3 cm) X-band sensors. Later, the Jet Propulsion Laboratory began its development of imaging radars with an airborne sensor, followed by the Seasat orbital radar in 1978. These systems were L-band (25 cm). Following Seasat, JPL embarked upon a series of Space Shuttle Imaging Radars: SIRA (1981), SIR-B (1984), and SIR-C (1994). The most recent in the series was the most capable radar sensor flown in space and acquired large numbers of data swaths in a variety of test areas around the world. The Mojave Desert-Death Valley region was one of those test areas, and was covered very well with 3 wavelengths, multiple polarizations, and at multiple angles. At the same time, the JPL aircraft radar program continued improving and collecting data over the Mojave Desert Death Valley region. Now called AIRSAR, the system includes 3 bands (P-band, 67 cm; L-band, 25 cm; C-band, 5 cm). Each band can collect all possible polarizations in a mode called polarimetry. In addition, AIRSAR can be operated in the TOPSAR mode wherein 2 antennas collect data interferometrically, yielding a digital elevation model (DEM). Both L-band and C-band can be operated in this way, with horizontal resolution of about 5 m and vertical errors less than 2 m. The findings and developments of these earlier investigations are discussed.

Fire Impacts on the Mojave Desert Ecosystem: Literature Review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fenstermaker Lynn

2012-01-01

The Nevada National Security Site (NNSS) is located within the Mojave Desert, which is the driest region in North America. Precipitation on the NNSS varies from an annual average of 130 millimeters (mm; 5.1 inches) with a minimum of 47 mm (1.9 inches) and maximum of 328 mm (12.9 inches) over the past 15 year period to an annual average of 205 mm (8.1 inches) with an annual minimum of 89 mm (3.5 inches) and maximum of 391 mm (15.4 inches) for the same time period; for a Frenchman Flat location at 970 meters (m; 3182 feet) and a Pahutemore » Mesa location at 1986 m (6516 feet), respectively. The combination of aridity and temperature extremes has resulted in sparsely vegetated basins (desert shrub plant communities) to moderately vegetated mountains (mixed coniferous forest plant communities); both plant density and precipitation increase with increasing elevation. Whereas some plant communities have evolved under fire regimes and are dependent upon fire for seed germination, plant communities within the Mojave Desert are not dependent on a fire regime and therefore are highly impacted by fire (Brown and Minnich, 1986; Brooks, 1999). As noted by Johansen (2003) natural range fires are not prevalent in the Mojave and Sonoran Deserts because there is not enough vegetation present (too many shrub interspaces) to sustain a fire. Fire research and hence publications addressing fires in the Southwestern United States (U.S.) have therefore focused on forest, shrub-steppe and grassland fires caused by both natural and anthropogenic ignition sources. In the last few decades, however, invasion of mid-elevation shrublands by non-native Bromus madritensis ssp. rubens and Bromus tectorum (Hunter, 1991) have been highly correlated with increased fire frequency (Brooks and Berry, 2006; Brooks and Matchett, 2006). Coupled with the impact of climate change, which has already been shown to be playing a role in increased forest fires (Westerling et al., 2006), it is likely that the fire frequency will further increase in the Mojave Desert (Knapp 1998; Smith et al., 1987; Smith et al., 2000).« less

Geophysical Investigations of a Proterozoic Carbonatite Terrane, southeast Mojave Desert, California

NASA Astrophysics Data System (ADS)

Denton, K. M.; Ponce, D. A.; Miller, D. M.; Peacock, J.; Miller, J. S.

2015-12-01

One of the world's largest rare-earth element-rich carbonatite deposits is located in the eastern Mojave Desert at Mountain Pass, California. The eastern Mojave Desert carbonatite terrane consists of a ~1.7 Ga gneiss and schist rocks that are host to a ~1.417 Ga (Premo, 2013) ultrapotassic intrusive suite (shonkinite, syenite, and granite) and a ~1.375 Ga (DeWitt, 1983) carbonatite deposit . Regional geophysical data indicate that this carbonatite terrane occurs within a north-northwest trending ~1-km wide bench in a gravity high and along the eastern edge of a prominent magnetic high in the eastern Clark Mountain Range. To improve our understanding of the geophysical and structural framework of the eastern Mojave carbonatite terrane, we collected over 2,300 gravity stations and over 640 physical rock property samples. Carbonatite rocks typically have distinct gravity, magnetic, and radioactive signatures because they are relatively dense, often contain magnetite, and are commonly enriched in thorium and/or uranium. Contrary to this trend, our results show that the carbonatite deposit is essentially nonmagnetic with an average susceptibility of 0.18 x 10-3 SI (n=31), and the ultrapotassic intrusive suite is very weakly magnetic with an average susceptibility of 2.0 x 10-3 SI (n=36). However, these rocks are found along a steep gradient of a prominent aeromagnetic anomaly. The lack of magnetic signature from the rocks of the eastern Mojave carbonatite terrane suggests alteration of magnetic minerals. This is corroborated by its location within a broader alteration zone and observed magnetic low. If so, such an alteration event occurred after emplacement of the carbonatite deposit, which likely remobilized rare earth elements in the surrounding rocks. Further, an alteration event is consistent with geology, high rare-earth element concentration, and unusual geochemistry of the carbonatite deposit. Temporal constraints (DeWitt, 1987; Premo, 2013) also suggest alteration of the carbonatite, as the apparent age of the carbonatite deposit is ~40 Ma younger than the associated, and likely contemporaneous ultrapotassic intrusive suite.

Reference intervals and physiologic alterations in hematologic and biochemical values of free-ranging desert tortoises in the Mojave Desert

USGS Publications Warehouse

Christopher, Mary M.; Berry, Kristin H.; Wallis, I.R.; Nagy, K.A.; Henen, B.T.; Peterson, C.C.

1999-01-01

Desert tortoise (Gopherus agassizii) populations have experienced precipitous declines resulting from the cumulative impact of habitat loss, and human and disease-related mortality. Evaluation of hematologic and biochemical responses of desert tortoises to physiologic and environmental factors can facilitate the assessment of stress and disease in tortoises and contribute to management decisions and population recovery. The goal of this study was to obtain and analyze clinical laboratory data from free-ranging desert tortoises at three sites in the Mojave Desert (California, USA) between October 1990 and October 1995, to establish reference intervals, and to develop guidelines for the interpretation of laboratory data under a variety of environmental and physiologic conditions. Body weight, carapace length, and venous blood samples for a complete blood count and clinical chemistry profile were obtained from 98 clinically healthy adult desert tortoises of both sexes at the Desert Tortoise Research Natural area (western Mojave), Goffs (eastern Mojave) and Ivanpah Valley (northeastern Mojave). Samples were obtained four times per year, in winter (February/March), spring (May/June), summer (July/August), and fall (October). Years of near-, above- and below-average rainfall were represented in the 5 yr period. Minimum, maximum and median values, and central 95 percentiles were used as reference intervals and measures of central tendency for tortoises at each site and/or season. Data were analyzed using repeated measures analysis of variance for significant (P < 0.01) variation on the basis of sex, site, season, and interactions between these variables. Significant sex differences were observed for packed cell volume, hemoglobin concentration, aspartate transaminase activity, and cholesterol, triglyceride, calcium, and phosphorus concentrations. Marked seasonal variation was observed in most parameters in conjunction with reproductive cycle, hibernation, or seasonal rainfall. Year-to-year differences and long-term alterations primarily reflected winter rainfall amounts. Site differences were minimal, and largely reflected geographic differences in precipitation patterns, such that results from these studies can be applied to other tortoise populations in environments with known rainfall and forage availability patterns.

A new reconstruction of the Paleozoic continental margin of southwestern North America: Implications for the nature and timing of continental truncation and the possible role of the Mojave-Sonora megashear

USGS Publications Warehouse

Stevens, C.H.; Stone, P.; Miller, J.S.

2005-01-01

Data bearing on interpretations of the Paleozoic and Mesozoic paleogeography of southwestern North America are important for testing the hypothesis that the Paleozoic miogeocline in this region has been tectonically truncated, and if so, for ascertaining the time of the event and the possible role of the Mojave-Sonora megashear. Here, we present an analysis of existing and new data permitting reconstruction of the Paleozoic continental margin of southwestern North America. Significant new and recent information incorporated into this reconstruction includes (1) spatial distribution of Middle to Upper Devonian continental-margin facies belts, (2) positions of other paleogeographically significant sedimentary boundaries on the Paleozoic continental shelf, (3) distribution of Upper Permian through Upper Triassic plutonic rocks, and (4) evidence that the southern Sierra Nevada and western Mojave Desert are underlain by continental crust. After restoring the geology of western Nevada and California along known and inferred strike-slip faults, we find that the Devonian facies belts and pre-Pennsylvanian sedimentary boundaries define an arcuate, generally south-trending continental margin that appears to be truncated on the southwest. A Pennsylvanian basin, a Permian coral belt, and a belt of Upper Permian to Upper Triassic plutons stretching from Sonora, Mexico, into westernmost central Nevada, cut across the older facies belts, suggesting that truncation of the continental margin occurred in the Pennsylvanian. We postulate that the main truncating structure was a left-lateral transform fault zone that extended from the Mojave-Sonora megashear in northwestern Mexico to the Foothills Suture in California. The Caborca block of northwestern Mexico, where Devonian facies belts and pre-Pennsylvanian sedimentary boundaries like those in California have been identified, is interpreted to represent a missing fragment of the continental margin that underwent ???400 km of left-lateral displacement along this fault zone. If this model is correct, the Mojave-Sonora megashear played a direct role in the Pennsylvanian truncation of the continental margin, and any younger displacement on this fault has been relatively small. ?? 2005 Geological Society of America.

VizieR Online Data Catalog: MOJAVE. XIII. New 15GHz observations on 1994-2013 (Lister+, 2016)

NASA Astrophysics Data System (ADS)

Lister, M. L.; Aller, M. F.; Aller, H. D.; Homan, D. C.; Kellermann, K. I.; Kovalev, Y. Y.; Pushkarev, A. B.; Richards, J. L.; Ros, E.; Savolainen, T.

2016-09-01

Starting with the 2cm Very Long Baseline Array (VLBA) survey in 1994 (Kellermann et al. 1998AJ....115.1295K), and continuing with the MOJAVE (Monitoring of Jets in Active Galactic Nuclei with VLBA Experiments) program (Lister et al. 2009, Cat. J/AJ/137/3718), we have carried out multi-epoch VLBA observations of several hundred of the brightest, most compact radio sources in the northern sky. In this paper, we present 1625 VLBA 15GHz contour maps of 295 AGNs for epochs between 1994 August 31 and 2013 August 20 that have not previously appeared in any paper from the MOJAVE (Lister & Homan 2005, Cat. J/AJ/130/1389; Lister et al. 2009, Cat. J/AJ/137/3718; Lister et al. 2013, Cat. J/AJ/146/120) or 2cm VLBA surveys (Kellermann et al. 1998AJ....115.1295K; Zensus et al. 2002AJ....124..662Z). These AGNs (see Table1) are from one or more of the following: the MOJAVE low-luminosity sample (Lister et al. 2013, Cat. J/AJ/146/120), the complete flux density-limited MOJAVE 1.5Jy sample (Lister et al. 2015, Cat. J/ApJ/810/L9), the VLBA 2cm survey (Kellermann et al. 1998AJ....115.1295K), the third EGRET gamma-ray catalog (Hartman et al. 1999, Cat. J/ApJS/123/79), or the 3FGL Fermi gamma-ray catalog (Acero et al. 2015, Cat. J/ApJS/218/23). Also included are some AGNs that were originally candidates for these samples, but did not meet the final selection criteria. We list the parameters of the contour maps in Table2. We modeled the (u, v) visibility data in Difmap (Shepherd 1997ASPC..125...77S) using a set of Gaussian features, which we list in Table3. We analyzed the kinematics of the robust Gaussian jet features in our sample using two methods. The results of these analyses are listed separately in Tables 4 and 5, respectively. (6 data files).

Monitoring ecosystem quality and function in arid settings of the Mojave Desert

USGS Publications Warehouse

Belnap, Jayne; Webb, Robert H.; Miller, Mark E.; Miller, David M.; DeFalco, Lesley A.; Medica, Philip A.; Brooks, Matthew L.; Esque, Todd C.; Bedford, Dave

2008-01-01

Monitoring ecosystem quality and function in the Mojave Desert is both a requirement of state and Federal government agencies and a means for determining potential long-term changes induced by climatic fluctuations and land use. Because it is not feasible to measure every attribute and process in the desert ecosystem, the choice of what to measure and where to measure it is the most important starting point of any monitoring program. In the Mojave Desert, ecosystem function is strongly influenced by both abiotic and biotic factors, and an understanding of the temporal and spatial variability induced by climate and landform development is needed to determine where site-specific measurements should be made. We review a wide variety of techniques for sampling, assessing, and measuring climatic variables, desert soils, biological soil crusts, annual and perennial vegetation, reptiles, and small mammals. The complete array of ecosystem attributes and processes that we describe are unlikely to be measured or monitored at any given location, but the array of possibilities allows for the development of specific monitoring protocols, which can be tailored to suit the needs of land-management agencies.

Compositional trends in aeolian dust along a transect across the southwestern United States

USGS Publications Warehouse

Goldstein, H.L.; Reynolds, R.L.; Reheis, M.C.; Yount, J.C.; Neff, J.C.

2008-01-01

Aeolian dust strongly influences ecology and landscape geochemistry over large areas that span several desert ecosystems of the southwestern United States. This study evaluates spatial and temporal variations and trends of the physical and chemical properties of dust in the southwestern United States by examining dust deposited in natural depressions on high isolated surfaces along a transect from the Mojave Desert to the central Colorado Plateau. Aeolian dust is recognized in these depressions on the basis of textural, chemical, isotopic, and mineralogical characteristics and comparisons of those characteristics to the underlying bedrock units. Spatial and temporal trends suggest that although local dust sources are important to the accumulated material in these depressions, Mojave Desert dust sources may also contribute. Depth trends in the depressions suggest that Mojave sources may have contributed more dust to the Colorado Plateau recently than in the past. These interpretations point to the important roles of far-traveled aeolian dust for landscape geochemistry and imply future changes to soil geochemistry under changing conditions in far-distant dust source areas. Copyright 2008 by the American Geophysical Union.

Clockwise rotation of the western Mojave Desert

NASA Technical Reports Server (NTRS)

Golombek, Matthew P.; Brown, Laurie L.

1988-01-01

A study of paleomagnetic data from Miocene volcanic rocks in the western Mojave Desert, which suggests about 25 deg of clockwise rotation, is presented. A total of 166 oriented core samples of two types of basalt were taken from 19 sites in the region. After demagnetization to 40 or 60 mT, application of structural corrections, and inversion of reversed sites, the data yielded an average direction of 51.6 deg inclination and 15.6 deg declination. When compared with the expected direction for Miocene rocks for stable North America, the direction for these Mojave rocks shows a clockwise rotation of 23.8 deg + or - 11.3 deg and a flattening of about 2.1 deg, a rotation which agrees in direction with oroclinal bending of the southern Sierra Nevada due to right-lateral shear along the western margin of North America. Most of this rotation is constrained by other paleomagnetic and strucural information to have occurred soon after the sampled basalts were deposited (about 20 Ma) and before about 16 Ma. These clockwise declination anomalies indicate that any subsequent counterclockwise rotation is small and/or compensated by previous clockwise rotation.

Late Quaternary stratigraphy and luminescence geochronology of the northeastern Mojave Desert

USGS Publications Warehouse

Mahan, S.A.; Miller, D.M.; Menges, C.M.; Yount, J.C.

2007-01-01

The chronology of the Holocene and late Pleistocene deposits of the northeastern Mojave Desert have been largely obtained using radiocarbon ages. Our study refines and extends this framework using optically stimulated luminescence (OSL) to date deposits from Valjean Valley, Silurian Lake Playa, Red Pass, and California Valley. Of particular interest are eolian fine silts incorporated in ground-water discharge (GWD) deposits bracketed at 185-140 and 20-50 ka. Alluvial fan deposits proved amenable for OSL by dating both eolian sand lenses and reworked eolian sand in a matrix of gravel that occurs within the fan stratigraphy. Lacustrine sand in spits and bars also yielded acceptable OSL ages. These OSL ages fill gaps in the geochronology of desert deposits, which can provide data relevant to understanding the responses of several depositional systems to regional changes in climate. This study identifies the most promising deposits for future luminescence dating and suggests that for several regions of the Mojave Desert, sediments from previously undated landforms can be more accurately placed within correct geologic map units.

Directly dated MIS 3 lake-level record from Lake Manix, Mojave Desert, California, USA

USGS Publications Warehouse

Reheis, Marith; Miller, David M.; McGeehin, John P.; Redwine, Joanna R.; Oviatt, Charles G.; Bright, Jordon E.

2015-01-01

An outcrop-based lake-level curve, constrained by ~ 70 calibrated 14C ages on Anodonta shells, indicates at least 8 highstands between 45 and 25 cal ka BP within 10 m of the 543-m upper threshold of Lake Manix in the Mojave Desert of southern California. Correlations of Manix highstands with ice, marine, and speleothem records suggest that at least the youngest three highstands coincide with Dansgaard–Oeschger (D–O) stadials and Heinrich events 3 and 4. The lake-level record is consistent with results from speleothem studies in the Southwest that indicate cool wet conditions during D–O stadials. Notably, highstands between 43 and 25 ka apparently occurred at times of generally low levels of pluvial lakes farther north as interpreted from core-based proxies. Mojave lakes may have been supported by tropical moisture sources during oxygen-isotope stage 3, perhaps controlled by southerly deflection of Pacific storm tracks due to weakening of the sea-surface temperature gradient in response to North Atlantic climate perturbations.

Livestock grazing and the desert tortoise in the Mojave Desert

USGS Publications Warehouse

Oldemeyer, John L.

1994-01-01

A large part of the Mojave Desert is not in pristine condition, and some current conditions can be related to past grazing-management practices. No information could be found on densities of the desert tortoise (Gopherus agassizii) or on vegetative conditions of areas that had not been grazed to allow managers a comparison of range conditions with data on tortoises. Experimental information to assess the effect of livestock grazing on tortoises is lacking, and researchers have not yet examined whether the forage that remains after grazing is sufficient to meet the nutritional needs of desert tortoises.

Biotic Processes Regulating the Carbon Balance of Desert Ecosystems - Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nowak, Robert S; Smith, Stanley D; Evans, Dave

2012-12-13

Our results from the 10-year elevated atmospheric CO{sub 2} concentration study at the Nevada Desert FACE (Free-air CO{sub 2} Enrichment) Facility (NDFF) indicate that the Mojave Desert is a dynamic ecosystem with the capacity to respond quickly to environmental changes. The Mojave Desert ecosystem is accumulating carbon (C), and over the 10-year experiment, C accumulation was significantly greater under elevated [CO{sub 2}] than under ambient, despite great fluctuations in C inputs from year to year and even apparent reversals in which [CO{sub 2}] treatment had greater C accumulations.

Proteus DSA control room in Mojave, CA

NASA Image and Video Library

2003-04-03

Proteus DSA control room in Mojave, CA (L to R) Jean-Pierre Soucy; Amphitech International Software engineer Craig Bomben; NASA Dryden Test Pilot Pete Siebold; (with headset, at computer controls) Scaled Composites pilot Bob Roehm; New Mexico State University (NMSU) UAV Technical Analysis Application Center (TAAC) Chuck Coleman; Scaled Composites Pilot Kari Sortland; NMSU TAAC Russell Wolfe; Modern Technology Solutions, Inc. Scaled Composites' unique tandem-wing Proteus was the testbed for a series of UAV collision-avoidance flight demonstrations. An Amphitech 35GHz radar unit installed below Proteus' nose was the primary sensor for the Detect, See and Avoid tests.

Environmental projects. Volume 7: Environmental resources document

NASA Technical Reports Server (NTRS)

Kushner, Len; Kroll, Glenn

1988-01-01

The Goldstone Deep Space Communications Complex (GDSCC) in Barstow, California, is part of the NASA Deep Space Network, one of the world's largest and most sensitive scientific telecommunications and radio navigation networks. Goldstone is managed, directed and operated by the Jet Propulsion Laboratory of Pasadena, California. The GDSCC includes five distinct operational sites: Echo, Venus, Mars, Apollo, and Mojave Base. Within each site is a Deep Space Station (DPS), consisting of a large dish antenna and its support facilities. As required by NASA directives concerning the implementation of the National Environmental Policy Act, each NASA field installation is to publish an Environmental Resources Document describing the current environment at the installation, including any adverse effects that NASA operations may have on the local environment.

Inventory of Amphibians and Reptiles at Manzanar National Historic Site, California

USGS Publications Warehouse

Persons, Trevor B.; Nowak, Erika M.; Hillard, Scott

2006-01-01

We conducted a baseline inventory for amphibians and reptiles at Manzanar National Historic Site (MANZ), Inyo County, California, in 2002-3. Objectives for this inventory were to: 1) inventory and document the occurrence of reptile and amphibian species at MANZ, with the goal of documenting at least 90% of the species present; 2) provide one voucher specimen for each species identified; 3) provide a GIS-referenced list of sensitive species that are known to be federally- or state-listed, rare, or worthy of special consideration that occur at MANZ; 4) describe park-wide distribution of federally- or state-listed, rare, or special concern species; 5) enter all species data into the National Park Service NPSpecies database; and 6) provide all deliverables as outlined in the Mojave Network Biological Inventory Study Plan. Survey methods included time-area constrained searches, lizard line transects, general surveys, nighttime road driving, and pitfall trapping. We documented the occurrence of ten reptile species (seven lizards and three snakes), but found no amphibians. Based on our findings, as well as literature review and searches for museum specimen records, we estimate inventory completeness for Manzanar to be 50%. Although the distribution and relative abundance of common lizard species is now known well enough to begin development of a monitoring protocol for that group, additional inventory work is needed in order to establish a baseline of species occurrence of amphibians and snakes at Manzanar. Key Words: amphibians, reptiles, Manzanar National Historic Site, Inyo County, California, Owens Valley, Mojave Desert, Great Basin Desert, inventory.

Postearthquake relaxation evidence for laterally variable viscoelastic structure and water content in the Southern California mantle

USGS Publications Warehouse

Pollitz, Fred

2015-01-01

I reexamine the lower crust and mantle relaxation following two large events in the Mojave Desert: the 1992 M7.3 Landers and 1999 M7.1 Hector Mine, California, earthquakes. Time series from continuous GPS sites out to 300 km from the ruptures are used to constrain models of postseismic relaxation. Crustal motions in the Mojave Desert region are elevated above background for several years following each event. To account for broadscale relaxation of the lower crust and mantle, the Burgers body model is employed, involving transient and steady state viscosities. Joint afterslip/postseismic relaxation modeling of the GPS time series up to one decade following the Hector Mine earthquake reveals a significant rheological contrast between a northwest trending “southwest domain” (that envelopes the San Andreas fault system and western Mojave Desert) and an adjacent “northeast domain” (that envelopes the Landers and Hector Mine rupture areas in the central Mojave Desert). The steady state viscosity of the northeast domain mantle asthenosphere is inferred to be ∼4 times greater than that of the southwest domain. This pattern is counter to that expected for regional heat flow, which is higher in the northeast domain, but it is explicable by means of a nonlinear rheology that includes dependence on both strain rate and water concentration. I infer that the southwest domain mantle has a relatively low steady state viscosity because of its high strain rate and water content. The relatively low mantle water content of the northeast domain is interpreted to result from the continual extraction of water through igneous and volcanic activity over the past ∼20 Myr.

Desert tortoise use of burned habitat in the Eastern Mojave desert

USGS Publications Warehouse

Drake, Karla K.; Esque, Todd C.; Nussear, Kenneth E.; DeFalco, Lesley; Scoles, Sara; Modlin, Andrew T.; Medica, Philip A.

2015-01-01

Wildfires burned 24,254 ha of critical habitat designated for the recovery of the threatened Mojave desert tortoise (Gopherus agassizii) in southern Nevada during 2005. The proliferation of non-native annual grasses has increased wildfire frequency and extent in recent decades and continues to accelerate the conversion of tortoise habitat across the Mojave Desert. Immediate changes to vegetation are expected to reduce quality of critical habitat, yet whether tortoises will use burned and recovering habitat differently from intact unburned habitat is unknown. We compared movement patterns, home-range size, behavior, microhabitat use, reproduction, and survival for adult desert tortoises located in, and adjacent to, burned habitat to understand how tortoises respond to recovering burned habitat. Approximately 45% of home ranges in the post-fire environment contained burned habitat, and numerous observations (n = 12,223) corroborated tortoise use of both habitat types (52% unburned, 48% burned). Tortoises moved progressively deeper into burned habitat during the first 5 years following the fire, frequently foraging in burned habitats that had abundant annual plants, and returning to adjacent unburned habitat for cover provided by intact perennial vegetation. However, by years 6 and 7, the live cover of the short-lived herbaceous perennial desert globemallow (Sphaeralcea ambigua) that typically re-colonizes burned areas declined, resulting in a contraction of tortoise movements from the burned areas. Health and egg production were similar between burned and unburned areas indicating that tortoises were able to acquire necessary resources using both areas. This study documents that adult Mojave desert tortoises continue to use habitat burned once by wildfire. Thus, continued management of this burned habitat may contribute toward the recovery of the species in the face of many sources of habitat loss.

An annual plant growth proxy in the Mojave Desert using MODIS-EVI data

USGS Publications Warehouse

Wallace, C.S.A.; Thomas, K.A.

2008-01-01

In the arid Mojave Desert, the phenological response of vegetation is largely dependent upon the timing and amount of rainfall, and maps of annual plant cover at any one point in time can vary widely. Our study developed relative annual plant growth models as proxies for annual plant cover using metrics that captured phenological variability in Moderate-Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) satellite images. We used landscape phenologies revealed in MODIS data together with ecological knowledge of annual plant seasonality to develop a suite of metrics to describe annual growth on a yearly basis. Each of these metrics was applied to temporally-composited MODIS-EVI images to develop a relative model of annual growth. Each model was evaluated by testing how well it predicted field estimates of annual cover collected during 2003 and 2005 at the Mojave National Preserve. The best performing metric was the spring difference metric, which compared the average of three spring MODIS-EVI composites of a given year to that of 2002, a year of record drought. The spring difference metric showed correlations with annual plant cover of R2 = 0.61 for 2005 and R 2 = 0.47 for 2003. Although the correlation is moderate, we consider it supportive given the characteristics of the field data, which were collected for a different study in a localized area and are not ideal for calibration to MODIS pixels. A proxy for annual growth potential was developed from the spring difference metric of 2005 for use as an environmental data layer in desert tortoise habitat modeling. The application of the spring difference metric to other imagery years presents potential for other applications such as fuels, invasive species, and dust-emission monitoring in the Mojave Desert.

Impact of Demographic Trends on Future Development Patterns and the Loss of Open Space in the California Mojave Desert

NASA Astrophysics Data System (ADS)

Gomben, Peter; Lilieholm, Robert; Gonzalez-Guillen, Manuel

2012-02-01

During the post-World War II era, the Mojave Desert Region of San Bernardino County, California, has experienced rapid levels of population growth. Over the past several decades, growth has accelerated, accompanied by significant shifts in ethnic composition, most notably from predominantly White non-Hispanic to Hispanic. This study explores the impacts of changing ethnicity on future development and the loss of open space by modeling ethnic propensities regarding family size and settlement preferences reflected by U.S. Census Bureau data. Demographic trends and land conversion data were obtained for seven Mojave Desert communities for the period between 1990 and 2001. Using a spatially explicit, logistic regression-based urban growth model, these data and trends were used to project community-specific future growth patterns from 2000 to 2020 under three future settlement scenarios: (1) an "historic" scenario reported in earlier research that uses a Mojave-wide average settlement density of 3.76 persons/ha; (2) an "existing" scenario based on community-specific settlement densities as of 2001; and (3) a "demographic futures" scenario based on community-specific settlement densities that explicitly model the Region's changing ethnicity. Results found that under the demographic futures scenario, by 2020 roughly 53% of within-community open space would remain, under the existing scenario only 40% would remain, and under the historic scenario model the communities would have what amounts to a deficit of open space. Differences in the loss of open space across the scenarios demonstrate the importance of considering demographic trends that are reflective of the residential needs and preferences of projected future populations.

Mojave Compliant Zone Structure and Properties: Constraints from InSAR and Mechanical Models

NASA Astrophysics Data System (ADS)

Hearn, E. H.; Fialko, Y.; Finzi, Y.

2007-12-01

Long-lived zones with significantly lower elastic strength than their surroundings are associated with active Mojave faults (e.g., Li et al., 1999; Fialko et al., 2002, 2004). In an earthquake these weak features concentrate strain, causing them to show up as anomalous, short length-scale features in SAR interferograms (Fialko et al., 2002). Fault-zone trapped wave studies indicate that the 1999 Hector Mine earthquake caused a small reduction in P- and S-wave velocities in a compliant zone along the Landers earthquake rupture (Vidale and Li, 2003). This suggests that coseismic strain concentration, and the resulting damage, in the compliant zone caused a further reduction in its elastic strength. Even a small coseismic strength drop should make a compliant zone (CZ) deform, in response to the total (not just the coseismic) stress. The strain should be in the sense which is compatible with the orientations and values of the region's principal stresses. However, as indicated by Fialko and co-workers (2002, 2004), the sense of coseismic strain of Mojave compliant zones was consistent with coseismic stress change, not the regional (background) stress. Here we use finite-element models to investigate how InSAR measurements of Mojave compliant zone coseismic strain places limits on their dimensions and on upper crustal stresses. We find that unless the CZ is shallow, narrow, and has a high Poisson's ratio (e.g., 0.4), CZ contraction under lithostatic stress overshadows deformation due to deviatoric background stress or coseismic stress change. We present ranges of CZ dimensions which are compatible with the observed surface deformation and address how these dimensions compare with new results from damage-controlled fault evolution models.

Impact of demographic trends on future development patterns and the loss of open space in the California Mojave Desert.

PubMed

Gomben, Peter; Lilieholm, Robert; Gonzalez-Guillen, Manuel

2012-02-01

During the post-World War II era, the Mojave Desert Region of San Bernardino County, California, has experienced rapid levels of population growth. Over the past several decades, growth has accelerated, accompanied by significant shifts in ethnic composition, most notably from predominantly White non-Hispanic to Hispanic. This study explores the impacts of changing ethnicity on future development and the loss of open space by modeling ethnic propensities regarding family size and settlement preferences reflected by U.S. Census Bureau data. Demographic trends and land conversion data were obtained for seven Mojave Desert communities for the period between 1990 and 2001. Using a spatially explicit, logistic regression-based urban growth model, these data and trends were used to project community-specific future growth patterns from 2000 to 2020 under three future settlement scenarios: (1) an "historic" scenario reported in earlier research that uses a Mojave-wide average settlement density of 3.76 persons/ha; (2) an "existing" scenario based on community-specific settlement densities as of 2001; and (3) a "demographic futures" scenario based on community-specific settlement densities that explicitly model the Region's changing ethnicity. Results found that under the demographic futures scenario, by 2020 roughly 53% of within-community open space would remain, under the existing scenario only 40% would remain, and under the historic scenario model the communities would have what amounts to a deficit of open space. Differences in the loss of open space across the scenarios demonstrate the importance of considering demographic trends that are reflective of the residential needs and preferences of projected future populations.

An Annual Plant Growth Proxy in the Mojave Desert Using MODIS-EVI Data.

PubMed

Wallace, Cynthia S A; Thomas, Kathryn A

2008-12-03

In the arid Mojave Desert, the phenological response of vegetation is largely dependent upon the timing and amount of rainfall, and maps of annual plant cover at any one point in time can vary widely. Our study developed relative annual plant growth models as proxies for annual plant cover using metrics that captured phenological variability in Moderate-Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) satellite images. We used landscape phenologies revealed in MODIS data together with ecological knowledge of annual plant seasonality to develop a suite of metrics to describe annual growth on a yearly basis. Each of these metrics was applied to temporally-composited MODIS-EVI images to develop a relative model of annual growth. Each model was evaluated by testing how well it predicted field estimates of annual cover collected during 2003 and 2005 at the Mojave National Preserve. The best performing metric was the spring difference metric, which compared the average of three spring MODIS-EVI composites of a given year to that of 2002, a year of record drought. The spring difference metric showed correlations with annual plant cover of R² = 0.61 for 2005 and R² = 0.47 for 2003. Although the correlation is moderate, we consider it supportive given the characteristics of the field data, which were collected for a different study in a localized area and are not ideal for calibration to MODIS pixels. A proxy for annual growth potential was developed from the spring difference metric of 2005 for use as an environmental data layer in desert tortoise habitat modeling. The application of the spring difference metric to other imagery years presents potential for other applications such as fuels, invasive species, and dust-emission monitoring in the Mojave Desert.

Monitoring Springs in the Mojave Desert Using Landsat Time Series Analysis

NASA Technical Reports Server (NTRS)

Potter, Christopher S.

2018-01-01

The purpose of this study, based on Landsat satellite data was to characterize variations and trends over 30 consecutive years (1985-2016) in perennial vegetation green cover at over 400 confirmed Mojave Desert spring locations. These springs were surveyed between in 2015 and 2016 on lands managed in California by the U.S. Bureau of Land Management (BLM) and on several land trusts within the Barstow, Needles, and Ridgecrest BLM Field Offices. The normalized difference vegetation index (NDVI) from July Landsat images was computed at each spring location and a trend model was first fit to the multi-year NDVI time series using least squares linear regression.Â

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tagestad, Jerry; Brooks, Matthew; Cullinan, Valerie

Mojave Desert ecosystem processes are dependent upon the amount and seasonality of precipitation. Multi-decadal periods of drought or above-average rainfall affect landscape vegetation condition, biomass and susceptibility to fire. The seasonality of precipitation events can also affect the likelihood of lightning, a key ignition source for fires. To develop an understanding of precipitation regimes and fire patterns we used monthly average precipitation data and GIS data representing burned areas from 1971-2010. We applied a K-means cluster analysis to the monthly precipitation data identifying three distinct precipitation seasons; winter (October – March), spring (April-June) and summer (July-September) and four discrete precipitationmore » regimes within the Mojave ecoregion.« less

Lithologic and ground-water data for monitoring sites in the Mojave River and Warren Valley basins, San Bernardino County, California, 1992-1998

USGS Publications Warehouse

Huff, Julia A.; Clark, Dennis A.; Martin, Peter

2002-01-01

Lithologic and ground-water data were collected at 85 monitoring sites constructed in the Mojave Water Agency Management area in San Bernardino County, California, as part of a series of cooperative studies between the U.S. Geological Survey and the Mojave Water Agency. The data are being used to evaluate and address water-supply and water-quality issues. This report presents a compilation of the data collected at these sites from 1992 through 1998, including location and design of the monitoring sites, lithologic data, geophysical logs, ground-water-level measurements, and water-quality analyses.One to five small (generally 2-inch) diameter wells were installed at each of the 85 monitoring sites to collect depth-dependent hydrologic data. Lithologic logs were compiled from descriptions of drill cuttings collected at each site and from observations recorded during the drilling of the borehole. Generalized stratigraphic columns were compiled by grouping similar lithologic units. Geophysical logs provide information on the character of the lithologic units and on the presence of ground water and the chemical characteristics of that water. Water-level and water-quality data were collected periodically from the sites during 1992 through 1998.

Gravity and Magnetic Investigations of the Mojave National Preserve and Adjacent Areas, California and Nevada

USGS Publications Warehouse

Langenheim, V.E.; Biehler, S.; Negrini, R.; Mickus, K.; Miller, D.M.; Miller, R.J.

2009-01-01

Gravity and aeromagnetic data provide the underpinnings of a hydrogeologic framework for the Mojave National Preserve by estimating the thickness of Cenozoic deposits and locating inferred structural features that influence groundwater flow. An inversion of gravity data indicates that thin (<1 km) basin deposits cover much of the Preserve, except for Ivanpah Valley and the Woods Mountains volcanic center. Localized areas of Cenozoic deposits thicker than 500 m are predicted beneath parts of Lanfair Valley, Fenner Valley, near Kelso, Soda Lake, and southeast of Baker. Along the southern margin of the Mojave National Preserve, basins greater than 1 km deep are located between the Clipper and Marble Mountains, between the Marble and Bristol Mountains, and south of the Bristol Mountains near Amboy. Both density and magnetization boundaries defined by horizontal-gradient analyses coincide locally with Cenozoic faults and can be used to extend these faults beneath cover. Magnetization boundaries also highlight the structural grain within the crystalline rocks and may serve as a proxy for fracturing, an important source of permeability within the generally impermeable basement rocks, thus mapping potential groundwater pathways through and along the mountain ranges in the study area.

Precipitation history and ecosystem response to multidecadal precipitation variability in the Mojave Desert region, 1893-2001

USGS Publications Warehouse

Hereford, R.; Webb, R.H.; Longpre, C.I.

2006-01-01

Precipitation varied substantially in the Mojave Desert through the 20th century in a manner broadly similar to the other warm North American deserts. Episodes of drought and prolonged dry conditions (1893-1904, ca. 1942-1975, and 1999-present) alternated with relatively wet periods (1905-ca. 1941 and ca. 1976-1998), probably because of global-scale climate fluctuations. These are the El Nin??o-Southern Oscillation that affects interannual climate and the Pacific Decadal Oscillation that evidently causes decadal-scale variability such as prolonged dry and wet episodes. Studies done in the late 20th century demonstrate that precipitation fluctuations affected populations of perennial vegetation, annuals, and small herbivores. Landscape rephotography reveals that several species, particularly creosote bush, increased in size and density during the ca. 1976-1998 wet period. A brief, intense drought from 1989 to 1991 and the ongoing drought caused widespread mortality of certain species; for example, chenopods and perennial grasses suffered up to 100% mortality. Drought pruning, the shedding of above-ground biomass to reduce carbon allocation, increased substantially during drought. Overall, drought had the greatest influence on the Mojave Desert ecosystem. ?? 2006.

Precipitation regime classification for the Mojave Desert: Implications for fire occurrence

USGS Publications Warehouse

Tagestad, Jerry; Brooks, Matthew L.; Cullinan, Valerie; Downs, Janelle; McKinley, Randy

2016-01-01

Long periods of drought or above-average precipitation affect Mojave Desert vegetation condition, biomass and susceptibility to fire. Changes in the seasonality of precipitation alter the likelihood of lightning, a key ignition source for fires. The objectives of this study were to characterize the relationship between recent, historic, and future precipitation patterns and fire. Classifying monthly precipitation data from 1971 to 2010 reveals four precipitation regimes: low winter/low summer, moderate winter/moderate summer, high winter/low summer and high winter/high summer. Two regimes with summer monsoonal precipitation covered only 40% of the Mojave Desert ecoregion but contain 88% of the area burned and 95% of the repeat burn area. Classifying historic precipitation for early-century (wet) and mid-century (drought) periods reveals distinct shifts in regime boundaries. Early-century results are similar to current, while the mid-century results show a sizeable reduction in area of regimes with a strong monsoonal component. Such a shift would suggest that fires during the mid-century period would be minimal and anecdotal records confirm this. Predicted precipitation patterns from downscaled global climate models indicate numerous epochs of high winter precipitation, inferring higher fire potential for many multi-decade periods during the next century.

Estimating wildfire risk on a Mojave Desert landscape using remote sensing and field sampling

USGS Publications Warehouse

Van Linn, Peter F.; Nussear, Kenneth E.; Esque, Todd C.; DeFalco, Lesley A.; Inman, Richard D.; Abella, Scott R.

2013-01-01

Predicting wildfires that affect broad landscapes is important for allocating suppression resources and guiding land management. Wildfire prediction in the south-western United States is of specific concern because of the increasing prevalence and severe effects of fire on desert shrublands and the current lack of accurate fire prediction tools. We developed a fire risk model to predict fire occurrence in a north-eastern Mojave Desert landscape. First we developed a spatial model using remote sensing data to predict fuel loads based on field estimates of fuels. We then modelled fire risk (interactions of fuel characteristics and environmental conditions conducive to wildfire) using satellite imagery, our model of fuel loads, and spatial data on ignition potential (lightning strikes and distance to roads), topography (elevation and aspect) and climate (maximum and minimum temperatures). The risk model was developed during a fire year at our study landscape and validated at a nearby landscape; model performance was accurate and similar at both sites. This study demonstrates that remote sensing techniques used in combination with field surveys can accurately predict wildfire risk in the Mojave Desert and may be applicable to other arid and semiarid lands where wildfires are prevalent.

Dynamics of cover, UV-protective pigments, and quantum yield in biological soil crust communities of an undisturbed Mojave Desert shrubland

USGS Publications Warehouse

Belnap, Jayne; Phillips, Susan L.; Smith, Stanley D.

2007-01-01

Biological soil crusts are an integral part of dryland ecosystems. We monitored the cover of lichens and mosses, cyanobacterial biomass, concentrations of UV-protective pigments in both free-living and lichenized cyanobacteria, and quantum yield in the soil lichen species Collema in an undisturbed Mojave Desert shrubland. During our sampling time, the site received historically high and low levels of precipitation, whereas temperatures were close to normal. Lichen cover, dominated by Collema tenax and C. coccophorum, and moss cover, dominated by Syntrichia caninervis, responded to both increases and decreases in precipitation. This finding for Collema spp. at a hot Mojave Desert site is in contrast to a similar study conducted at a cool desert site on the Colorado Plateau in SE Utah, USA, where Collema spp. cover dropped in response to elevated temperatures, but did not respond to changes in rainfall. The concentrations of UV-protective pigments in free-living cyanobacteria at the Mojave Desert site were also strongly and positively related to rainfall received between sampling times (R2 values ranged from 0.78 to 0.99). However, pigment levels in the lichenized cyanobacteria showed little correlation with rainfall. Quantum yield in Collema spp. was closely correlated with rainfall. Climate models in this region predict a 3.5–4.0 °C rise in temperature and a 15–20% decline in winter precipitation by 2099. Based on our data, this rise in temperature is unlikely to have a strong effect on the dominant species of the soil crusts. However, the predicted drop in precipitation will likely lead to a decrease in soil lichen and moss cover, and high stress or mortality in soil cyanobacteria as levels of UV-protective pigments decline. In addition, surface-disturbing activities (e.g., recreation, military activities, fire) are rapidly increasing in the Mojave Desert, and these disturbances quickly remove soil lichens and mosses. These stresses combined are likely to lead to shifts in species composition and the local extirpation of some lichen or moss species. As these organisms are critical components of nutrient cycling, soil fertility, and soil stability, such changes are likely to reverberate throughout these ecosystems.

Visibility monitoring in the southern California desert for the Department of Defense: Research on operations-limiting visual extinction, RESOLVE protocol

NASA Astrophysics Data System (ADS)

Blumenthal, D.; Trijonis, J.

1984-09-01

A decrease in visibility in the R2508 airspace (in the western Mojave Desert in southern California) since the mid-1940s, when flight test and training facilities were established in this region, is adversely affecting flight and test operations. The Joint Policy and Planning Board (JPPB) of the Department of Defense has initiated studies and discussions of the visibility issue with the goal of developing a management strategy to maintain and optimize the operational capabilities of the test facilities. To identify trends in and sources of visibility degradation in the desert, JPPB initiated two programs: (1) a compilation and review of the historical visibility and air quality data in the California desert region, to be coordinated by the California Desert Air Working Group (CDAWG) and funded by CDAWG participants; and (2) RESearch on Operations-Limiting Visual Extinction (RESOLVE), which involves measuring the visibility at key receptor sites (monitoring stations) in the R2508 region. The report describes the current status of and future plans for the RESOLVE program.

Environmental projects. Volume 5, part 1: Study of subsurface contamination. Part 2: Guide to implement environmental compliance programs

NASA Technical Reports Server (NTRS)

Bengelsdorf, I.

1988-01-01

In support of the national goal for the preservation of the environment and the protection of human health and safety, NASA, the Jet Propulsion Laboratory, and the Goldstone Deep Space Communications Complex have adopted the position that their operating installations shall maintain a high level of compliance in regard to regulations concerning environmental hazards. An investigation carried out by Engineering Science, Inc. focused on possible underground contamination that may have resulted from leaks and/or spills from storage facilities at the Goldstone Communications Complex. It also involved the cleanup of a non-hazardous waste dumpsite at the Mojave Base Site at the Goldstone complex. The report also includes details of the management duties and responsibilities needed to maintain compliance with environmental laws and regulations.

Geologic Setting, Geohydrology, and Ground-Water Quality near the Helendale Fault in the Mojave River Basin, San Bernardino County, California

USGS Publications Warehouse

Stamos, Christina L.; Cox, Brett F.; Izbicki, John A.; Mendez, Gregory O.

2003-01-01

The proximity of the Mojave River ground-water basin to the highly urbanized Los Angeles region has resulted in rapid population growth and, consequently, an increase in the demand for water. The Mojave River, the primary source of surface water for the region, normally is dry--except for periods of flow after intense storms; therefore, the region relies almost entirely on ground water to meet its agricultural and municipal needs. The area where the Helendale Fault intersects the Mojave River is of particular hydrogeologic interest because of its importance as a boundary between two water-management subareas of the Mojave Water Agency. The fault is the boundary between the upper Mojave River Basin (Oeste, Alto, and Este subareas) and the lower Mojave River Basin (Centro and Baja subareas); specifically, the fault is the boundary between the Alto and the Centro subareas. To obtain the information necessary to help better understand the hydrogeology of the area near the fault, multiple-well monitoring sites were installed, the surface geology was mapped in detail, and water-level and water-quality data were collected from wells in the study area. Detailed surficial geologic maps and water-level measurements indicate that the Helendale Fault impedes the flow of ground water in the deeper regional aquifer, but not in the overlying floodplain aquifer. Other faults mapped in the area impede the flow of ground water in both aquifers. Evidence of flowing water in the Mojave River upgradient of the Helendale Fault exists in the historical record, suggesting an upward gradient of ground-water flow. However, water-level data from this study indicate that pumping upstream of the Helendale Fault has reversed the vertical gradient of ground-water flow since predevelopment conditions, and the potential now exists for water to flow downward from the floodplain aquifer to the regional aquifer. Sixty-seven ground-water samples were analyzed for major ions, nutrients, and stable isotopes of oxygen and hydrogen from 34 wells within the study area between May 1990 and November 1999. Dissolved-solids concentrations in water samples from 14 wells in the floodplain aquifer ranged from 339 to 2,330 milligrams per liter (mg/L) with a median concentration of 825 mg/L. Concentrations in water from 11 of these wells exceeded the U.S. Environmental Protection Agency (USEPA) Secondary Maximum Contaminant Level (SMCL) of 500 mg/L. Dissolved-solids concentrations of water from nine wells sampled in the regional aquifer ranged from 479 to 946 mg/L with a median concentration of 666 mg/L. Concentrations in at least one sample of water from each of the wells in the regional aquifer exceeded the USEPA SMCL for dissolved solids. Arsenic concentrations in water from 14 wells in the floodplain aquifer ranged from less than the detection limit of 2 micrograms per liter (?g/L) to a maximum of 34 ?g/L with a median concentration of 6 ?g/L. Concentrations in water from six of the 14 wells exceeded the USEPA Maximum Contaminant Level (MCL) for arsenic of 10 ?g/L. Arsenic concentrations in water from nine wells in the regional aquifer ranged from less than the detection limit of 2 to 130 ?g/L with a median concentration of 11 ?g/L. Concentrations in water from five of these nine wells exceeded the USEPA MCL for arsenic. Dissolved-solids concentrations in water from seven wells completed in the igneous and metamorphic basement rocks that underlie the floodplain and regional aquifers ranged from 400 to 3,190 mg/L with a median concentration of 1,410 mg/L. Concentrations in water from all but one of the seven wells sampled exceeded the USEPA SMCL for dissolved solids. Concentrations in water from the basement rocks exceeded the USEPA SMCL for arsenic of 10 ?g/L in five of the seven wells. The high concentrations of arsenic, dissolved solids, and other constituents probably occur naturally. Stable isotopes of oxygen and hydrogen indicate that before pumping began in

ATS-F ground station integration

NASA Technical Reports Server (NTRS)

1975-01-01

The ATS ground stations were described, including a system description, operational frequencies and bandwidth, and a discussion of individual subsystems. Each station configuration is described as well as its floor plan. The station performance, as tested by the GSI, is displayed in chart form providing a summary of the more important parameters tested. This chart provides a listing of test data, by site, for comparison purposes. Also included is a description of the ATS-6 experiments, the equipment, and interfaces required to perform these experiments. The ADP subsystem and its role in the experiments is also described. A description of each program task and a summary of the activities performed were then given. These efforts were accomplished at the Rosman II Ground Station, located near Rosman N.C., the Mojave Ground Station, located near Barstow Ca., and the GSI Contractors plant located near Baltimore, Md.

Mars Gardens in the University - Red Thumbs: Growing Vegetables in Martian regolith simulant.

NASA Astrophysics Data System (ADS)

Guinan, Edward Francis

2018-01-01

Over the next few decades NASA and private enterprise missions plan to send manned missions to Mars with the ultimate aim to establish a permanent human presence on this planet. For a self-sustaining colony on Mars it will be necessary to provide food by growing plants in sheltered greenhouses on the Martian surface. As part of an undergraduate student project in Astrobiology at Villanova University, experiments are being carried out, testing how various plants grow in Martian regolith. A wide sample of plants are being grown and tested in Mars regolith simulant commercially available from The Martian Garden (TheMartian Garden.com). This Mars regolith simulant is based on Mojave Mars Simulant (MMS) developed by NASA and JPL for the Mars Phoenix mission. The MMS is based on the Mojave Saddleback basalt similar that used by JPL/NASA. Additional reagents were added to this iron rich basalt to bring the chemical content close to actual Mars regolith. The MMS used is an approximately 90% similar to regolith found on the surface of Mars - excluding poisonous perchlorates commonly found on actual Mars surface.The students have selected various vegetables and herbs to grow and test. These include carrots, spinach, dandelions, kale, soy beans, peas, onions, garlic and of course potatoes and sweet potatoes. Plants were tested in various growing conditions, using different fertilizers, and varying light conditions and compared with identical “control plants” grown in Earth soil / humus. The results of the project will be discussed from an education view point as well as from usefulness for fundamental research.We thank The Martian Garden for providing Martian regolith simulant at education discounted prices.

Desert Scrublands

USGS Publications Warehouse

Jones, L.L.C.; Halama, K.J.; Lovich, R.E.

2016-01-01

Desert scrublands comprise the lower to mid-elevation portions of four different ecosystems including the Chihuahuan, Great Basin, Mojave and Sonoran Deserts. Together the area inside their outer boundaries includes over 8% of the surface area of the United States. Despite significant differences in the flora and fauna of these bioregions they all share the common trait of being arid shrub-steppe ecosystems, receiving, on average, less than 254 mm of rain per year. The austere nature of these landscapes belies their significant biodiversity, the amazing behavioral and physiological adaptations of the biota, and the fragility of the ecosystems to human disturbances. For example, the Mojave Desert alone has at least 250 species of ephemeral plants, mostly winter annuals, and up to 90% are endemic.

Polarization signatures for abandoned agricultural fields in the Manix Basin area of the Mojave Desert - Can polarimetric SAR detect desertification?

NASA Technical Reports Server (NTRS)

Ray, Terrill W.; Farr, Tom G.; Van Zyl, Jakob J.

1992-01-01

Radar backscatter from abandoned circular alfalfa fields in the Manix Basin area of the Mojave desert shows systematic changes with length of abandonment. The obliteration of circular planting rows by surface processes could account for the disappearance of bright spokes, which seem to be reflection patterns from remnants of the planting rows, with increasing length of abandonment. An observed shift in the location of the maximum L-band copolarization return away from VV, as well as an increase in surface roughness, both occurring with increasing age of abandonment, seems to be attributable to the formation of wind ripples on the relatively vegetationless fields.

Physical and Chemical Data from Eolian Sediment Collected Along a Transect from the Mojave Desert to the Colorado Plateau

USGS Publications Warehouse

Goldstein, Harland L.; Reynolds, Richard L.; Reheis, Marith C.; Yount, James C.; Lamothe, Paul J.

2007-01-01

This report presents data and describes the methodology for magnetic, geochemical, and textural measurements of sediment and bedrock samples collected along a transect across the Southwestern United States (fig. 1). The results presented here support a study that examines compositional variations of mineral dust deposited during the past few centuries in isolated natural traps spanning a region from the Mojave Desert of southern California to the central Colorado Plateau (Goldstein and others, in press; fig. 1). In particular, the study addresses the spatial and temporal variations in dust composition in the context of landscape geochemistry over a large area of the southwestern United States.

Fault tectonics and earthquake hazards in the Peninsular Ranges, Southern California. [including San Diego River, Otay Mts., Japatul Valley, Barrett Lake, Horsethief Canyon, Pine Valley Creek, Pine Creek, and Mojave Desert

NASA Technical Reports Server (NTRS)

Merifield, P. M. (Principal Investigator)

1975-01-01

The author has identified the following significant results. Thin sections of rock exposed along the San Diego River linear were prepared and determined to be fault breccia. Single band and ratio images of the western Mojave Desert were prepared from the multispectral scanner digital tapes. Subtle differences in color of soil and rock are enhanced on the ratio images. Two north-northeast trending linears (Horsethief Canyon and Pine Valley Creek) and an east-west linear (Pine Creek) were concluded to have resulted from erosion along well-developed foliation in crystalline basement rocks.

Cumulative biological impacts framework for solar energy projects in the California Desert

USGS Publications Warehouse

Davis, Frank W.; Kreitler, Jason R.; Soong, Oliver; Stoms, David M.; Dashiell, Stephanie; Hannah, Lee; Wilkinson, Whitney; Dingman, John

2013-01-01

This project developed analytical approaches, tools and geospatial data to support conservation planning for renewable energy development in the California deserts. Research focused on geographical analysis to avoid, minimize and mitigate the cumulative biological effects of utility-scale solar energy development. A hierarchical logic model was created to map the compatibility of new solar energy projects with current biological conservation values. The research indicated that the extent of compatible areas is much greater than the estimated land area required to achieve 2040 greenhouse gas reduction goals. Species distribution models were produced for 65 animal and plant species that were of potential conservation significance to the Desert Renewable Energy Conservation Plan process. These models mapped historical and projected future habitat suitability using 270 meter resolution climate grids. The results were integrated into analytical frameworks to locate potential sites for offsetting project impacts and evaluating the cumulative effects of multiple solar energy projects. Examples applying these frameworks in the Western Mojave Desert ecoregion show the potential of these publicly-available tools to assist regional planning efforts. Results also highlight the necessity to explicitly consider projected land use change and climate change when prioritizing areas for conservation and mitigation offsets. Project data, software and model results are all available online.

Photosynthetic strategies of two Mojave Desert shrubs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kleinkopf, G.E.; Hartsock, T.L.; Wallace, A.

1980-01-01

Photosynthetic production of two Mojave Desert shrubs was measured under natural growing conditions. Measurements of photosynthesis, transpiration, resistances to water vapor flux, soil moisture potential, and tissue water potential were made. Atriplex canescens (Pursh) Nutt., a member of the C/sub 4/ biochemical carbon dioxide fixation group was highly competitive in growth rate and production during conditions of adequate soil moisture. As soil moisture conditions declined to minus 40 bars, the net photosynthetic rate of Atriplex decreased to zero. However, the C/sub 3/ shrub species Larrea tridentata (Sesse and Moc. ex DC.) Cov. was able to maintain positive net photosynthetic productionmore » during conditions of high temperature and extreme low soil moisture through the major part of the season. The comparative advantages of the C/sub 4/ versus the C/sub 3/ pathway of carbon fixation was lost between these two species as the soil moisture potential declined to minus 40 bars. Desert plants have diffferent strategies for survival, one of the strategies being the C/sub 4/ biochemical carbon fixation pathway. However, many of the plants are members of the C/sub 3/ group. In this instance, the C/sub 4/ fixation pathway does not confer an added advantage to the productivity of the species in the Mojave Desert. Species distribution based on comparative photosynthetic production is discussed« less

Influence of Complex Terrain on Wind Fields in the Mojave Desert, Southwestern US

NASA Astrophysics Data System (ADS)

Clow, G. D.; Reynolds, R. L.; Urban, F. E.; Bogle, R.; Vogel, J. M.

2009-12-01

The complex terrain of southern California has important effects on the winds in this dust-producing region. We use the Weather Research and Forecasting Model (WRF) to investigate the influences of rugged topography on the wind field in the Mojave Desert at a variety of scales. For this study, the WRF model was used in a retrospective mode over the time period 2000-to-present, with horizontal resolutions as fine as 1-km in specific areas of interest (i.e., known dust-source areas). At a regional scale, the juxtaposition of California's Central Valley with the Sierra Nevada Mountain Range often generates a band of strong winds extending eastward from the southern end of the Sierra Nevada and Tehachapi Mountains across the Mojave Desert and into Arizona. At finer scales, WRF-derived winds within this band reveal terrain deflection, focusing, channeling, and rapid direction change over short distances. These effects are important for assessing the capacity of wind to produce dust at potential dust-source areas during specific events, and for determining dust-transport pathways. Comparison of the WRF results during strong wind events with data from meteorological stations having dust emission instruments (saltation sensors and/or wind-triggered time-lapse cameras) help elucidate landscape conditions that influence dust emission and patterns of dust transport.

Speciation, population structure, and demographic history of the Mojave Fringe-toed Lizard (Uma scoparia), a species of conservation concern

PubMed Central

Gottscho, Andrew D; Marks, Sharyn B; Jennings, W Bryan

2014-01-01

The North American deserts were impacted by both Neogene plate tectonics and Quaternary climatic fluctuations, yet it remains unclear how these events influenced speciation in this region. We tested published hypotheses regarding the timing and mode of speciation, population structure, and demographic history of the Mojave Fringe-toed Lizard (Uma scoparia), a sand dune specialist endemic to the Mojave Desert of California and Arizona. We sampled 109 individual lizards representing 22 insular dune localities, obtained DNA sequences for 14 nuclear loci, and found that U. scoparia has low genetic diversity relative to the U. notata species complex, comparable to that of chimpanzees and southern elephant seals. Analyses of genotypes using Bayesian clustering algorithms did not identify discrete populations within U. scoparia. Using isolation-with-migration (IM) models and a novel coalescent-based hypothesis testing approach, we estimated that U. scoparia diverged from U. notata in the Pleistocene epoch. The likelihood ratio test and the Akaike Information Criterion consistently rejected nested speciation models that included parameters for migration and population growth of U. scoparia. We reject the Neogene vicariance hypothesis for the speciation of U. scoparia and define this species as a single evolutionarily significant unit for conservation purposes. PMID:25360285

MOJAVE - XIV. Shapes and opening angles of AGN jets

NASA Astrophysics Data System (ADS)

Pushkarev, A. B.; Kovalev, Y. Y.; Lister, M. L.; Savolainen, T.

2017-07-01

We present 15 GHz stacked VLBA images of 373 jets associated with active galactic nuclei (AGNs) having at least five observing epochs within a 20 yr time interval 1994-2015 from the Monitoring Of Jets in Active galactic nuclei with VLBA Experiments (MOJAVE) programme and/or its precursor, the 2-cm VLBA Survey. These data are supplemented by 1.4 GHz single-epoch VLBA observations of 135 MOJAVE AGNs to probe larger scale jet structures. The typical jet geometry is found to be close to conical on scales from hundreds to thousands of parsecs, while a number of galaxies show quasi-parabolic streamlines on smaller scales. A true jet geometry in a considerable fraction of AGNs appears only after stacking epochs over several years. The jets with significant radial accelerated motion undergo more active collimation. We have analysed total intensity jet profiles transverse to the local jet ridgeline and derived both apparent and intrinsic opening angles of the flows, with medians of 21.5° and 1.3°, respectively. The Fermi LAT-detected gamma-ray AGNs in our sample have, on average, wider apparent and narrower intrinsic opening angle, and smaller viewing angle than non-LAT-detected AGNs. We have established a highly significant correlation between the apparent opening angle and gamma-ray luminosity, driven by Doppler beaming and projection effects.

Effects of high fire frequency in creosote bush scrub vegetation of the Mojave Desert

USGS Publications Warehouse

Brooks, M.L.

2012-01-01

Plant invasions can increase fire frequency in desert ecosystems where fires were historically infrequent. Although there are many resource management concerns associated with high frequency fire in deserts, fundamental effects on plant community characteristics remain largely unstudied. Here I describe the effects of fire frequency on creosote bush scrub vegetation in the Mojave Desert, USA. Biomass of the invasive annual grass Bromus rubens L. increased following fire, but did not increase further with additional fires. In contrast, density, cover and species richness of native perennial plants each decreased following fire and continued to decrease with subsequent fires, although not as dramatically as after the initial fire. Responses were similar 5 and 14 years post-fire, except that cover of Hymenoclea salsola Torr. & A. Gray and Achnatherum speciosa Trin. & Rupr. both increased in areas burnt once. These results suggest that control of B. rubens may be equally warranted after one, two or three fires, but revegetation of native perennial plants is most warranted following multiple fires. These results are valid within the scope of this study, which is defined as relatively short term vegetation responses (???14 years) to short fire return intervals (6.3 and 7.3 years for the two and three fire frequency levels) within creosote bush scrub of the Mojave Desert. ?? 2012 IAWF.

Are Mojave Desert annual species equal? Resource acquisition and allocation for the invasive grass Bromus madritensis subsp. rubens (Poaceae) and two native species

USGS Publications Warehouse

Defalco, Lesley A.; Bryla, David R.; Smith-Longozo, Vickie; Nowak, Robert S.

2003-01-01

Abundance of invasive plants is often attributed to their ability ot outcompete native species. We compared resource acquisition and allocation of the invasive annual grass Bromus madritensis subsp. rubens with that of two native Mojave Desert annuals, Vulpia octoflora and Descurainia pinnata, in a glasshouse experiment. Each species was grown in monoculture at two densities and two levels of N availability to compare how these annuals capture resources and to understand their relative sensitivities to environmental change. During >4 mo of growth, Bromus used water more rapidly and had greater biomass and N content than the natives, partly because of its greater root-surface area and its exploitation of deep soils. Bromus also had greater N uptake, net assimilation and transpiration rates, and canopy area than Vulpia. Resource use by Bromuswas less sensitive to changes in N availability or density than were the natives. The two native species in this study produced numerous small seeds that tended to remain dormant, thus ensuring escape of offspring from unfavorable germination conditions; Bromus produced fewer but larger seeds that readily germinated. Collectively, these traits give Bromus the potential to rapidly establish in diverse habitats of the Mojave Desert, thereby gaining an advantage over coexisting native species.

Wash flow disturbance and summer wash flow in the Mojave Desert: Influence on dispersion, production, and physiological functioning of dominant shrubs

NASA Astrophysics Data System (ADS)

Newlander, April

In many Mojave Desert ecosystems, water infiltrates to root-zones in greatest proportion via washes. As such, washes have a pronounced effect on plant dispersion and size across these landscapes. Desert roads alter the natural spatial patterns of washes on alluvial fans (locally called bajadas) and potentially affect plant production and distribution. As a winter-rainfall dominated ecosystem, climate changes in the Mojave Desert that increase summer precipitation may also play an important role in altering vegetation processes influenced by washes. Road effects on the spatial distribution of desert plants on a Mojave Desert bajada were examined using remotely sensed LiDAR data and ground based measurements of plant size. Plant physiological responses to summer wash flow were also quantified by measuring gas exchange and water status of two dominant perennial species, Larrea tridentata and Ambrosia dumosa. Larrea and Ambrosia plants were nearly 7x and 4x larger where wash flow has been enhanced by road culverts, relative to undisturbed areas and areas where flow has been cut-off by the presence of a road/railroad. Clustering of large plants occurred along wash margins, with clustering most pronounced in areas of enhanced wash flow. No clustering was found where wash flow has been eliminated. For ecophysiological traits, both species showed pronounced responses to the pulse of water; however, these responses varied as a function of distance from wash. Larrea plants within 3 m and Ambrosia plants within ca. 2 m from the wash responded to the pulse of water. Leaf phenology dictated the timing of carbon gain as Larrea experienced a rapid but short-lived increase in stomatal conductance compared to a significant response for over a month following the pulse for Ambrosia. These results indicate that disturbance of desert washes has a pronounced impact on vegetation structure, and changing climatic conditions that impact plant function could potentially lead to even greater vegetation shifts through time.

Fault connectivity, distributed shortening, and impacts on geologic- geodetic slip rate discrepancies in the central Mojave Desert, California

NASA Astrophysics Data System (ADS)

Selander, J.; Oskin, M. E.; Cooke, M. L.; Grette, K.

2015-12-01

Understanding off-fault deformation and distribution of displacement rates associated with disconnected strike-slip faults requires a three-dimensional view of fault geometries. We address problems associated with distributed faulting by studying the Mojave segment of the East California Shear Zone (ECSZ), a region dominated by northwest-directed dextral shear along disconnected northwest- southeast striking faults. We use a combination of cross-sectional interpretations, 3D Boundary Element Method (BEM) models, and slip-rate measurements to test new hypothesized fault connections. We find that reverse faulting acts as an important means of slip transfer between strike-slip faults, and show that the impacts of these structural connections on shortening, uplift, strike-slip rates, and off-fault deformation, help to reconcile the overall strain budget across this portion of the ECSZ. In detail, we focus on the Calico and Blackwater faults, which are hypothesized to together represent the longest linked fault system in the Mojave ECSZ, connected by a restraining step at 35°N. Across this restraining step the system displays a pronounced displacement gradient, where dextral offset decreases from ~11.5 to <2 km from south to north. Cross-section interpretations show that ~40% of this displacement is transferred from the Calico fault to the Harper Lake and Blackwater faults via a set of north-dipping thrust ramps. Late Quaternary dextral slip rates follow a similar pattern, where 1.4 +0.8/-0.4 mm/yr of slip along the Calico fault south of 35°N is distributed to the Harper Lake, Blackwater, and Tin Can Alley faults. BEM model results using revised fault geometries for the Mojave ECSZ show areas of uplift consistent with contractional structures, and fault slip-rates that more closely match geologic data. Overall, revised fault connections and addition of off-fault deformation greatly reduces the discrepancy between geodetic and geologic slip rates.

Estimates of density, detection probability, and factors influencing detection of burrowing owls in the Mojave Desert

USGS Publications Warehouse

Crowe, D.E.; Longshore, K.M.

2010-01-01

We estimated relative abundance and density of Western Burrowing Owls (Athene cunicularia hypugaea) at two sites in the Mojave Desert (200304). We made modifications to previously established Burrowing Owl survey techniques for use in desert shrublands and evaluated several factors that might influence the detection of owls. We tested the effectiveness of the call-broadcast technique for surveying this species, the efficiency of this technique at early and late breeding stages, and the effectiveness of various numbers of vocalization intervals during broadcasting sessions. Only 1 (3) of 31 initial (new) owl responses was detected during passive-listening sessions. We found that surveying early in the nesting season was more likely to produce new owl detections compared to surveying later in the nesting season. New owls detected during each of the three vocalization intervals (each consisting of 30 sec of vocalizations followed by 30 sec of silence) of our broadcasting session were similar (37, 40, and 23; n 30). We used a combination of detection trials (sighting probability) and double-observer method to estimate the components of detection probability, i.e., availability and perception. Availability for all sites and years, as determined by detection trials, ranged from 46.158.2. Relative abundance, measured as frequency of occurrence and defined as the proportion of surveys with at least one owl, ranged from 19.232.0 for both sites and years. Density at our eastern Mojave Desert site was estimated at 0.09 ?? 0.01 (SE) owl territories/km2 and 0.16 ?? 0.02 (SE) owl territories/km2 during 2003 and 2004, respectively. In our southern Mojave Desert site, density estimates were 0.09 ?? 0.02 (SE) owl territories/km2 and 0.08 ?? 0.02 (SE) owl territories/km 2 during 2004 and 2005, respectively. ?? 2010 The Raptor Research Foundation, Inc.

Gravity and magnetic studies of the eastern Mojave Desert, California and Nevada

USGS Publications Warehouse

Denton, Kevin M.; Ponce, David A.

2016-06-17

IntroductionFrom May 2011 to August 2014, the U.S. Geological Survey (USGS) collected gravity data at more than 2,300 stations and physical property measurements on more than 640 rock samples from outcrops in the eastern Mojave Desert, California and Nevada. Gravity, magnetic, and physical-property data are used to study and locate regional crustal structures as an aid to understanding the geologic framework related to mineral resources of the eastern Mojave Desert.The eastern Mojave Desert is host to a world-class rare earth element carbonatite deposit located at Mountain Pass, California. Carbonatites are typically defined as magmatic rocks with high modal abundances of primary carbonate minerals >50 weight percent and elevated abundances of rare earth elements (REEs) (Nelson and others, 1988; Woolley and Kempe, 1989). The “Sulphide Queen” carbonatite ore deposit is a composite, tabular body made up of sills and dikes of REE-bearing sovites and beforsites that occurs just south of the Clark Mountain Range along a north-northwest trending fault-bounded block that extends along the northeast edge of the Mescal Range and northwestern extent of Ivanpah Mountains. This early to middle Proterozoic block is composed of a 1.7 Ga metamorphic complex of gneiss and schist that underwent widespread metamorphism and associated plutonism during the Ivanpah orogeny (Miller and others, 2007). Subsequently, these rocks were intruded by a series of granitoids, which included the 1.4 Ga (DeWitt and others, 1987) ultrapotassic alkaline suite of intrusions that are spatially and temporally associated with hundreds of dikes, outcrops, and a carbonatite ore body. The relative age sequence of this intrusive suite of alkaline rocks from oldest to youngest includes shonkinite, mesosyenite, syenite, quartz syenite, potassic granite, carbonatite, and late shonkinite dikes (Olson and others, 1954; Wooden and Miller, 1990; Haxel, 2005; Miller and others, 2007).

Detection and measurement of land subsidence using interferometric synthetic aperture radar and Global Positioning System, San Bernardino County, Mojave Desert, California

USGS Publications Warehouse

Sneed, Michelle; Ikehara, Marti E.; Stork, Sylvia V.; Amelung, Falk; Galloway, Devin L.

2003-01-01

Land subsidence associated with ground-water-level declines has been recognized as a potential problem in parts of the Mojave Desert, California. Ground water has been the primary source of domestic, agricultural, and municipal water supplies in the desert since the early 1900s. Pumping of ground water from the Mojave River and Morongo ground-water basins in the southwestern Mojave Desert resulted in water-level declines of more than 30 meters (100 feet) between the 1950s and the 1990s. A Global Positioning System (GPS) survey of a geodetic network was used to determine the location, extent, and magnitude of vertical land-surface changes in Lucerne Valley in the Morongo ground-water basin. The GPS survey was conducted in 1998 to estimate historical elevation changes by comparing GPS-derived elevations with historical elevations (which were available for some of the monuments in the network as early as 1944) and to establish baseline values that can be used for comparisons with future GPS surveys. The GPS measurements indicated that about 600 millimeters (2 feet) [plus or minus 1,500 millimeters (5 feet)] of subsidence occurred at three of the monuments between 1969 and 1998 but that very little to no vertical change in position occurred at seven other monuments in the network. Water levels in the area of subsidence in Lucerne Valley declined about 15 meters (50 feet) during 1970-98. Interferometric synthetic aperture radar (InSAR) methods were used to characterize vertical land-surface changes in the Mojave River and Morongo ground-water basins during various intervals of time between 1992 and 1999. Interferograms, InSAR-generated displacement maps, show that subsidence ranging from 45 to 90 mm (0.15 to 0.3 ft) occurred in four areas of these two ground-water basins--the El Mirage, Lockhart-Harper Lake (dry), Newberry Springs, and Lucerne Valley areas. Some of the InSAR measurements were affected by the earthquakes at Landers and Hector Mine, California, and by atmospheric artifacts. Water-level data were examined for areas undergoing vertical land-surface changes to determine whether the vertical land-surface changes may be related to aquifer-system compaction caused by ground-water-level changes. Temporally relevant water-level data were sparse for some areas, particularly the El Mirage and Lockhart-Harper Lake (dry) areas. Water levels in wells proximate to the subsiding areas generally declined between 1992 and 1999; water levels in some wells proximate to the subsiding areas experienced seasonal periods of declines and recoveries.

Preliminary surficial geologic map of a Calico Mountains piedmont and part of Coyote Lake, Mojave desert, San Bernardino County, California

USGS Publications Warehouse

Dudash, Stephanie L.

2006-01-01

This 1:24,000 scale detailed surficial geologic map and digital database of a Calico Mountains piedmont and part of Coyote Lake in south-central California depicts surficial deposits and generalized bedrock units. The mapping is part of a USGS project to investigate the spatial distribution of deposits linked to changes in climate, to provide framework geology for land use management (http://deserts.wr.usgs.gov), to understand the Quaternary tectonic history of the Mojave Desert, and to provide additional information on the history of Lake Manix, of which Coyote Lake is a sub-basin. Mapping is displayed on parts of four USGS 7.5 minute series topographic maps. The map area lies in the central Mojave Desert of California, northeast of Barstow, Calif. and south of Fort Irwin, Calif. and covers 258 sq.km. (99.5 sq.mi.). Geologic deposits in the area consist of Paleozoic metamorphic rocks, Mesozoic plutonic rocks, Miocene volcanic rocks, Pliocene-Pleistocene basin fill, and Quaternary surficial deposits. McCulloh (1960, 1965) conducted bedrock mapping and a generalized version of his maps are compiled into this map. McCulloh's maps contain many bedrock structures within the Calico Mountains that are not shown on the present map. This study resulted in several new findings, including the discovery of previously unrecognized faults, one of which is the Tin Can Alley fault. The north-striking Tin Can Alley fault is part of the Paradise fault zone (Miller and others, 2005), a potentially important feature for studying neo-tectonic strain in the Mojave Desert. Additionally, many Anodonta shells were collected in Coyote Lake lacustrine sediments for radiocarbon dating. Preliminary results support some of Meek's (1999) conclusions on the timing of Mojave River inflow into the Coyote Basin. The database includes information on geologic deposits, samples, and geochronology. The database is distributed in three parts: spatial map-based data, documentation, and printable map graphics of the database. Spatial data are distributed as an ArcInfo personal geodatabase, or as tabular data in the form of Microsoft Access Database (MDB) or dBase Format (DBF) file formats. Documentation includes this file, which provides a discussion of the surficial geology and describes the format and content of the map data, and Federal Geographic Data Committee (FGDC) metadata for the spatial map information. Map graphics files are distributed as Postscript and Adobe Acrobat Portable Document Format (PDF) files, and are appropriate for representing a view of the spatial database at the mapped scale.

Two lithospheric profiles across southern California derived from gravity and seismic data

USGS Publications Warehouse

Romanyuk, T.; Mooney, W.D.; Detweiler, S.

2007-01-01

We present two detailed 2-D density transects for the crust and uppermost mantle across southern California using a linear gravity inversion technique. This technique parameterizes the crust and upper mantle as a set of blocks that are based on published geologic and seismic models. Each block can have a range of densities that are constrained where possible by borehole measurements, seismic velocities, and petrologic data. To further constrain the models, it is assumed that the lithosphere is close to isostatic equilibrium at both ends of the profiles, in the deep ocean and east of the Mojave Desert. We calculate the lithostatic pressure variations field for the whole cross section to rule out the geophysically insignificant solutions. In the linear equation, ?? = a + bV (V, seismic P-wave velocity; ??, density), which approximates the mantle density-velocity (??-V) relationship, different coefficients for b were evaluated. Lower coefficients (b 0.3) imply that other effects, such as composition and/or metamorphic changes, play an important role in the mantle. Density models were constructed with the coefficient b ranging from 0 to 0.6. The results indicate that a high b value in the mantle ??-V relationship is associated with less dense crust in the Mojave block and more dense crust in the Catalina schist block. In the less dense Mojave block, the average density of the whole crust is ???2.75 g/cm3, while that of the lower crust is ???2.72 g/cm3. These densities imply a high silica content in the crust, and a minor fraction of basic rock in the lower crust, or perhaps the absence of a basaltic layer altogether. By comparison, the average density of a typical continental stable platform is ???2.85 g/cm3. Models with higher b coefficients (0.5-0.6) are characterized by a large isostatic imbalance. On the other hand, lower b values (0-0.2) require a consolidated whole crust density in the Mojave Desert of ???2.78 g/cm3, and a lower crust density of ???2.89 g/cm3 with mostly basaltic composition. This contradicts the observed, lower Vp/Vs-ratio in the Mojave Desert associated with mostly felsic and low-density crust. Models with lower b coefficients (0.1-0.2) are characterized by an absence of local Airy compensation beneath the San Gabriel Mountains at the LARSE-1 profile. These, and other non-gravity arguments, suggest optimal solutions to the mantle ??-V relation of b ??? 0.2-0.4. This, in turn, means that both thermal and petrological effects occur inside the downwelling of the uppermost mantle high velocity body located beneath the Transverse Ranges. During the development of this mantle downwelling, the basaltic layer of the Mojave block was likely eroded and pulled down into the high velocity body. Those basaltic fragments may have been transformed into eclogites, and this metamorphic change implies a higher b-coefficient density-velocity relationship than would be expected for a purely thermal process.

Role of pioneer species in revegetation of disturbed desert areas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wallace, A.; Romney, E.M.

1980-01-01

The northern Mojave Desert, as are many deserts, is characterized in part by small fertile islands in which exist individual shrub clumps each containing two or more plants. These fertile sites promote characteristic organization of both plant and animal activity in the desert. Destruction of these fertile sites make revegetation extremely difficult because most seedlings germinate in these sites. Some pioneer species do, however, germinate and survive in the bare areas between the fertile sites. Four such species in the northern Mojave Desert are Acamptopappus shockleyi Gray, Lepidium fremontii Wats., Sphaeralcea ambigua Gray, and Atriplex confertifolia (Torr. and Frem.) Wats.more » These four-species may have a role in starting new fertile islands.« less

The Goldstone solar system radar: A science instrument for planetary research

NASA Technical Reports Server (NTRS)

Dvorsky, J. D.; Renzetti, N. A.; Fulton, D. E.

1992-01-01

The Goldstone Solar System Radar (GSSR) station at NASA's Deep Space Communications Complex in California's Mojave Desert is described. A short chronological account of the GSSR's technical development and scientific discoveries is given. This is followed by a basic discussion of how information is derived from the radar echo and how the raw information can be used to increase understanding of the solar system. A moderately detailed description of the radar system is given, and the engineering performance of the radar is discussed. The operating characteristics of the Arcibo Observatory in Puerto Rico are briefly described and compared with those of the GSSR. Planned and in-process improvements to the existing radar, as well as the performance of a hypothetical 128-m diameter antenna radar station, are described. A comprehensive bibliography of referred scientific and engineering articles presenting results that depended on data gathered by the instrument is provided.

The Mojave Subsurface Bio-Geochemistry Explorer (MOSBE)

NASA Technical Reports Server (NTRS)

Guerrero, J.; Beegle, L.; Abbey, W.; Bhartia, R.; Kounaves, S.; Russell, M.; Towles, D.

2012-01-01

The MOSBE Team has developed a terrestrial field campaign to explore two subsurface biological habitats under the Mojave Desert. This field campaign will not only help us understand terrestrial desert biology, but also will develop methodologies and strategies for potential future Mars missions that would seek to explore the Martian subsurface. We have proposed to the ASTEP program to integrate a suite of field demonstrated instruments with a 20 m subsurface drill as a coherent unit, the Mojave Subsurface Bio-geochemistry Explorer. The ATK Space Modular Planetary Drill System (MPDS) requires no drilling fluid, which allows aseptic sampling, can penetrate lithic ground up to 20 meters of depth, and utilizes less than 100 Watts throughout the entire depth. The drill has been developed and demonstrated in field testing to a depth of 10 meters in Arizona, December 2002. In addition to caching a continuous core throughout the drilling depth, it also generates and caches cuttings and fines that are strata-graphically correlated with the core. As a core segment is brought to the surface, it will be analyzed for texture and structure by a color microscopic imager and for relevant chemistry and mineralogy with a UV fluorescence/Raman spectrometer. Organic and soluble ionic species will be identified through two instruments -- a microcapillary electrophoresis, and an ion trap mass spectrometer that have been developed under PIDDP, ASTID and MIDP funding.

A fault is born: The Landers-Mojave earthquake line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nur, A.; Ron, H.

1993-04-01

The epicenter and the southern portion of the 1992 Landers earthquake fell on an approximately N-S earthquake line, defined by both epicentral locations and by the rupture directions of four previous M>5 earthquakes in the Mojave: The 1947 Manix; 1975 Galway Lake; 1979 Homestead Valley: and 1992 Joshua Tree events. Another M 5.2 earthquake epicenter in 1965 fell on this line where it intersects the Calico fault. In contrast, the northern part of the Landers rupture followed the NW-SE trending Camp Rock and parallel faults, exhibiting an apparently unusual rupture kink. The block tectonic model (Ron et al., 1984) combiningmore » fault kinematic and mechanics, explains both the alignment of the events, and their ruptures (Nur et al., 1986, 1989), as well as the Landers kink (Nur et al., 1992). Accordingly, the now NW oriented faults have rotated into their present direction away from the direction of maximum shortening, close to becoming locked, whereas a new fault set, optimally oriented relative to the direction of shortening, is developing to accommodate current crustal deformation. The Mojave-Landers line may thus be a new fault in formation. During the transition of faulting from the old, well developed and wak but poorly oriented faults to the strong, but favorably oriented new ones, both can slip simultaneously, giving rise to kinks such as Landers.« less

Constraining the location of the Archean--Proterozoic suture in the Great Basin based on magnetotelluric soundings

USGS Publications Warehouse

Rodriguez, Brian D.; Sampson, Jay A.

2012-01-01

It is important to understand whether major mining districts in north-central Nevada are underlain by Archean crust, known to contain major orogenic gold deposits, or, alternatively, by accreted crust of the Paleoproterozoic Mojave province. Determining the location and orientation of the Archean-Proterozoic suture zone between the Archean crust and Mojave province is also critical because it may influence subsequent patterns of sedimentation, deformation, magmatism, and hydrothermal activity. In the Great Basin, the attitude of the suture zone is unknown because it is concealed below cover. A regional magnetotelluric sounding profile along the Utah-Nevada State line reveals a deeply penetrating, broad electrical conductor that may be the Archean-Proterozoic suture zone in the northwest corner of Utah. This major crustal conductor's strike direction is northwest, where it broadens to about 80 km wide below about 3-km depth. These results suggest that the southwestern limit of intact Archean crust in this part of the Great Basin is farther north than previously reported. These results also suggest that the major gold belts in north-central Nevada are located over the Paleoproterozoic Mojave province, and the Archean terrain lies northeast in the northwest corner of Utah. Rifted Archean crust segments south and west of the suture suggest that future mineral exploration northeast of current mineral trends may yield additional gold deposits.

78 FR 28776 - Approval and Promulgation of Implementation Plans; Georgia; State Implementation Plan...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-16

... Section of this Federal Register, EPA is approving the State's implementation plan revision as a direct... Promulgation of Implementation Plans; Georgia; State Implementation Plan Miscellaneous Revisions AGENCY... State Implementation Plan (SIP) submitted by the Georgia Environmental Protection Division to EPA in...

Rapid scientific response to Landers quake

NASA Astrophysics Data System (ADS)

Mori, J.; Hudnut, K.; Jones, L.; Hauksson, E.; Hutton, K.

Early on the morning of June 28, 1992, millions of people in southern California were awakened by the largest earthquake (Ms 7.5, Mw 7.4) in the western U.S. in the past 40 years. The quake initiated near the town of Landers, Calif., at 11:57 (GMT) and ruptured to the north and then the northwest along a 70-km stretch of the Mojave Shear Zone. Fortunately, the strongest shaking occurred in uninhabited regions of the Mojave desert, but one child was killed in Yucca Valley and 400 people were injured in the surrounding area. The communities of Landers, Yucca Valley, and Joshua Tree in San Bernardino County sustained significant ($100 million) damage to buildings and roads. Damage to water and power lines also caused problems in many of the desert areas.

REMOTE-SENSING MINERAL DISCOVERIES IN THE MOJAVE DESERT OF CALIFORNIA.

USGS Publications Warehouse

Raines, Gary L.; Hoover, Donald B.; Collins, William E.

1984-01-01

As a result of remote sensing studies in the Mojave Desert of California three previously unknown stockwork molybdenum systems have been discovered. It is not known if economic deposits of molybdenum and associated minerals occur in these areas; there is, however, sufficient data to judge that these areas are worthy of further exploration. The purpose of this paper is to present case histories of two of these discoveries. These discoveries have been made from laboratory analyses of Landsat multispectral scanner images to map limonitic materials and from field reconnaissance to determine if the limonite is due to hydrothermal alteration. In those areas that seemed most promising, airborne spectrometer surveys were employed to mapped Al-OH minerals, and audio-magnetotelluric (AMT) and telluric-traversing surveys were performed to obtain information at depth.

Ecology of a population of subsidized predators: Common ravens in the central Mojave Desert, California

USGS Publications Warehouse

Boarman, W.I.; Patten, M.A.; Camp, R.J.; Collis, S.J.

2006-01-01

Human subsidies have resulted in the rapid growth of populations of common ravens (Corvus corax) in the Mojave Desert. This is a management concern because ravens prey on threatened desert tortoises (Gopherus agassizii). We conducted weekly counts for 29 months at 10 sites on the US Army's National Training Center, Fort Irwin, California to evaluate factors affecting the distribution of ravens. Raven abundance varied seasonally, diurnally, and with human abundance. It was greatest near resource subsidies, specifically the landfill and sewage ponds. Although other studies have documented heavy use of landfills by ravens, the use of sewage ponds had not been previously reported in the published literature. We suggest that raven management should focus on reducing access to anthropogenic resources. ?? 2006.

Earth Observation

NASA Image and Video Library

2014-06-23

ISS040-E-017377 (23 June 2014) --- One of the Expedition 40 crew members aboard the International Space Station recorded this image showing several states in the USA and a small part of Mexico, including Baja California, on June 23, 2014. Parts of Nevada are visible in the bottom of the frame. The area in the Mojave Desert where many space shuttle missions successfully ended is visible near the scene's center. The Gulf of Cortez and several hundred miles of the Pacific coast line of Mexico and California are visible in the top portion of the photo. The heavily populated Los Angeles Basin is just above the Mojave site of shuttle landings, with the San Diego area partially obscured by the docked Russian Soyuz vehicle in the foreground. The Salton Sea is just above left center frame.

A study of the depth of weathering and its relationship to the mechanical properties of near-surface rocks in the Mojave Desert

USGS Publications Warehouse

Stierman, D.J.; Healy, J.H.

1985-01-01

Weathered granite extends 70 m deep at Hi Vista in the arid central Mojave Desert of southern California. The low strength of this granite is due to the alteration of biotite and chlorite montmorillonite. Deep weathering probably occurs in most granites, although we cannot rule out some anomalous mechanisms at Hi Vista. Geophysical instruments set in these slightly altered rocks are limited by the unstable behavior of the rocks. Thus, tectonic signals from instruments placed in shallow boreholes give vague results. Geophysical measurements of these weathered rocks resemble measurements of granitic rocks near major faults. The rheology of the rocks in which instruments are placed limits the useful sensitivity of the instruments. ?? 1985 Birkha??user Verlag.

ARC-2007-ACD07-0056-035

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-031

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-067

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-065

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-050

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-071

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-115

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-085

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-119

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-051

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-058

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Desert , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-136

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-042

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-027

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-137

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-135

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-140

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-075

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-032

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-117

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-034

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-043

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-096

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-063

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-081

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-024

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-023

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Desert , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-108

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-132

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-044

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-089

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-138

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-021

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-041

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-110

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-109

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-134

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-102

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-139

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-028

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-070

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-133

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-018

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-020

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-112

NASA Image and Video Library

2007-03-27

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-054

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-048

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-080

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

ARC-2007-ACD07-0056-030

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/

Helium isotope studies in the Mojave Desert, California: Implications for groundwater chronology and regional seismicity

USGS Publications Warehouse

Kulongoski, J.T.; Hilton, David R.; Izbicki, J.A.

2003-01-01

We report helium isotope and concentration results for groundwaters from the western Mojave River Basin (MRB), 130 km east of Los Angeles, CA. The basin lies adjacent to the NW-SE trending San Andreas Fault (SAF) system. Samples were collected along two groundwater flowpaths that originate in the San Gabriel Mountains and discharge to the Mojave River located ???32 km to the northeast. Additional groundwater samples were collected from Mojave River Deposits underlying the Mojave River. The primary objective of this study is to identify and quantify crustal and mantle helium contributions to the regional groundwater system. A total of 27 groundwaters, sampled previously for chemistry and isotope systematics (including 14C activity) have measured helium concentrations that increase along flowpaths from 9.9??10-8 to 1.0??10-4 cm3 STP g-1 H2O. Concomitantly, 3He/4He ratios decrease from 0.84RA to 0.11RA (RA equals the 3He/4He ratio in air=1.4??10-6). We did not record 3He/4He ratios equivalent to crustal-production values (???0.02RA) in any sample. Dissolved helium concentrations were resolved into components associated with solubility equilibration, air entrainment, mantle-derivation, in-situ production within the aquifer, and extraneous crustal fluxes. All samples contained the first four components, but only older samples had the superimposed effects of helium derived from a crustal flux. The radiogenic He component has chronological significance, and good concordance between 4He and 14C ages for younger groundwaters (<25,000 year) demonstrates the integrity of the 4 He-chronometer in this setting. Helium-rich waters could also be dated with the 4He technique, but only by first isolating the whole crustal flux (3-10??10-6 cm3 STP cm-2 year-1). Mantle-derived 3He (3Hem) is present in all MRB samples irrespective of distance from the SAF. However, regional-aquifer groundwaters near the terminus of the flowpath have a significantly greater content of mantle-derived 3He in comparison with more modern samples. We propose that faults in the basin other than the SAF may be an additional source of mantle-derived helium. The large range in 3He m concentrations may be related to fault activity; however, groundwaters with lower and more constant 3Hem contents may indicate that seismic activity along the SAF has been relatively constant for the past 30,000 years, demonstrating that ancient groundwaters may serve as an archive for paleo-seismic events. ?? 2003 Elsevier B.V. All rights reserved. All rights reserved.

Active tectonics of the northern Mojave Desert: The 2017 Desert Symposium field trip road log

USGS Publications Warehouse

Miller, David; Reynolds, R.E.; Phelps, Geoffrey; Honke, Jeff; Cyr, Andrew J.; Buesch, David C.; Schmidt, Kevin M.; Losson, G.

2017-01-01

The 2017 Desert Symposium field trip will highlight recent work by the U.S. Geological Survey geologists and geophysicists, who have been mapping young sediment and geomorphology associated with active tectonic features in the least well-known part of the eastern California Shear Zone (ECSZ). This area, stretching from Barstow eastward in a giant arc to end near the Granite Mountains on the south and the Avawatz Mountains on the north (Fig. 1-1), encompasses the two major structural components of the ECSZ—east-striking sinistral faults and northwest-striking dextral faults—as well as reverseoblique and normal-oblique faults that are associated with topographic highs and sags, respectively. In addition, folds and stepovers (both restraining stepovers that form pop-up structures and releasing stepovers that create narrow basins) have been identified. The ECSZ is a segment in the ‘soft’ distributed deformation of the North American plate east of the San Andreas fault (Fig. 1-1), where it takes up approximately 20-25% of plate motion in a broad zone of right-lateral shear (Sauber et al., 1994) The ECSZ (sensu strictu) begins in the Joshua Tree area and passes north through the Mojave Desert, past the Owens Valley-to-Death Valley swath and northward, where it is termed the Walker Lane. It has been defined as the locus of active faulting (Dokka and Travis, 1990), but when the full history from about 10 Ma forward is considered, it lies in a broader zone of right shear that passes westward in the Mojave Desert to the San Andreas fault (Mojave strike-slip province of Miller and Yount, 2002) and passes eastward to the Nevada state line or beyond (Miller, this volume).We will visit several accessible highlights for newly studied faults, signs of young deformation, and packages of syntectonic sediments. These pieces of a complex active tectonic puzzle have yielded some answers to longstanding questions such as: How is fault slip transfer in this area accommodated between northwest-striking dextral faults and eaststriking sinistral faults?How is active deformation on the Ludlow fault transferred northward, presumably to connect to the southern Death Valley fault zone?When were faults in this area of the central Mojave Desert initiated?Are faults in this area more or less active than faults in the ECSZ to the west?What is the role of NNW-striking faults and when did they form?How has fault slip changed over time? Locations and fault names are provided in figure 1-2. Important turns and locations are identified with locations in the projection: UTM, zone 11; datum NAD 83: (578530 3917335).

50 CFR 600.1008 - Implementation plan and implementation regulations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Implementation plan and implementation... Capacity Reduction Framework § 600.1008 Implementation plan and implementation regulations. (a) As soon as... period, a proposed implementation plan and implementation regulations. During the public comment period...

Heat Stress Equation Development and Usage for Dryden Flight Research Center (DFRC)

NASA Technical Reports Server (NTRS)

Houtas, Franzeska; Teets, Edward H., Jr.

2012-01-01

Heat Stress Indices are equations that integrate some or all variables (e.g. temperature, relative humidity, wind speed), directly or indirectly, to produce a number for thermal stress on humans for a particular environment. There are a large number of equations that have been developed which range from simple equations that may ignore basic factors (e.g. wind effects on thermal loading, fixed contribution from solar heating) to complex equations that attempt to incorporate all variables. Each equation is evaluated for a particular use, as well as considering the ease of use and reliability of the results. The meteorology group at the Dryden Flight Research Center has utilized and enhanced the American College of Sports Medicine equation to represent the specific environment of the Mojave Desert. The Dryden WBGT Heat Stress equation has been vetted and implemented as an automated notification to the entire facility for the safety of all personnel and visitors.

Negative impacts of invasive plants on conservation of sensitive desert wildlife

USGS Publications Warehouse

Drake, K. Kristina; Bowen, Lizabeth; Nussear, Kenneth E.; Esque, Todd C.; Berger, Andrew J.; Custer, Nathan; Waters, Shannon C.; Johnson, Jay D.; Miles, A. Keith; Lewison, Rebecca L.

2016-01-01

Habitat disturbance from development, resource extraction, off-road vehicle use, and energy development ranks highly among threats to desert systems worldwide. In the Mojave Desert, United States, these disturbances have promoted the establishment of nonnative plants, so that native grasses and forbs are now intermixed with, or have been replaced by invasive, nonnative Mediterranean grasses. This shift in plant composition has altered food availability for Mojave Desert tortoises (Gopherus agassizii), a federally listed species. We hypothesized that this change in forage would negatively influence the physiological ecology, immune competence, and health of neonatal and yearling tortoises. To test this, we monitored the effects of diet on growth, body condition, immunological responses (measured by gene transcription), and survival for 100 captive Mojave tortoises. Tortoises were assigned to one of five diets: native forbs, native grass, invasive grass, and native forbs combined with either the native or invasive grass. Tortoises eating native forbs had better body condition and immune functions, grew more, and had higher survival rates (>95%) than tortoises consuming any other diet. At the end of the experiment, 32% of individuals fed only native grass and 37% fed only invasive grass were found dead or removed from the experiment due to poor body conditions. In contrast, all tortoises fed either the native forb or combined native forb and native grass diets survived and were in good condition. Health and body condition quickly declined for tortoises fed only the native grass (Festuca octoflora) or invasive grass (Bromus rubens) with notable loss of fat and muscle mass and increased muscular atrophy. Bromus rubens seeds were found embedded in the oral mucosa and tongue in most individuals eating that diet, which led to mucosal inflammation. Genes indicative of physiological, immune, and metabolic functions were transcribed at lower levels for individuals fed B. rubens, indicating potential greater susceptibility to disease or other health-related problems. This study highlights the negative indirect effects of invasive grasses, such as red brome, in desert ecosystems, and provides definitive evidence of a larger negative consequence to health, survival, and ultimately population recruitment for Mojave Desert tortoises than previously understood.

Radar Imagery of Asteroid 2014 JO25

NASA Image and Video Library

2017-04-19

This composite of 30 images of asteroid 2014 JO25 was generated with radar data collected using NASA Goldstone Solar System Radar in California Mojave Desert. https://photojournal.jpl.nasa.gov/catalog/PIA21594

77 FR 58565 - Federal Property Suitable as Facilities To Assist the Homeless

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-21

..., Department of the Navy, Asset Management Division, Naval Facilities Engineering Command, Washington Navy Yard... California Aiken Mine Trailer Mojave Nat'l Preserve Baker CA Landholding Agency: Interior Property Number...

Mountainous Crater Rim on Mars

NASA Image and Video Library

2013-10-17

This is a screen shot from a high-definition simulated movie of Mojave Crater on Mars, based on images taken by the High Resolution Imaging Science Experiment HiRISE camera on NASA Mars Reconnaissance Orbiter.

Factors influencing the rates, processes and magnitude of accumulation of carbon in desert soils

NASA Technical Reports Server (NTRS)

Mcfadden, Leslie D.

1994-01-01

This report summarizes research funded through NASA's Soil Landscape Climate Program which includes studies of the systematics of carbon storage and flux in the terrestrial environment, specifically terrestrial soils. Efforts focussed on the nature of carbon behavior in arid environments, where the majority of the carbon is present as inorganic carbon stored as pedogenic carbonate in desert calcic soils. Studies were supported of soils in two areas of western North America's major deserts: the Mojave Desert and the Chihuahuan Desert. Part 1 of this report summarizes the results of research conducted in the area of the Providence Mountains, California in the eastern Mojave Desert. Part 2 of this report summarizes the results of research in the Sevilleta Wildlife Refuge in central New Mexico, one of the sites of the UMN Biology Department's Long Term Ecological Research.

F-15 HiDEC in flight over Mojave desert

NASA Technical Reports Server (NTRS)

1990-01-01

NASA's F-15 HIDEC (Highly Integrated Digital Electronic Control) research aircraft cruises over California's Mojave Desert at sunset on a flight out of the Dryden Flight Research Center, Edwards, California. The aircraft was used to carry out research on engine and flight control systems and most recently demonstrated the use of computer-assisted engine controls as a means of landing an aircraft safely with only engine power if its normal control surfaces such as elevators, rudders or ailerons are disabled. The aircraft also tested and evaluated a computerized self-repair flight control system for the Air Force that detects damaged or failed flight control surfaces, and then reconfigures undamaged flight surfaces so the mission can continue or the aircraft is landed safely. Nearly all research being carried out in the HIDEC program is applicable to future civilian and military aircraft.

ARC-2007-ACD07-0056-064

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/ shown here: Monika Kress, Professor of Astronomy at San Jose State University

Recovery of severely compacted soils in the Mojave Desert, California, USA

USGS Publications Warehouse

Webb, R.H.

2002-01-01

Often as a result of large-scale military maneuvers in the past, many soils in the Mojave Desert are highly vulnerable to soil compaction, particularly when wet. Previous studies indicate that natural recovery of severely compacted desert soils is extremely slow, and some researchers have suggested that subsurface compaction may not recover. Poorly sorted soils, particularly those with a loamy sand texture, are most vulnerable to soil compaction, and these soils are the most common in alluvial fans of the Mojave Desert. Recovery of compacted soil is expected to vary as a function of precipitation amounts, wetting-and-drying cycles, freeze-thaw cycles, and bioturbation, particularly root growth. Compaction recovery, as estimated using penetration depth and bulk density, was measured at 19 sites with 32 site-time combinations, including the former World War II Army sites of Camps Ibis, Granite, Iron Mountain, Clipper, and Essex. Although compaction at these sites was caused by a wide variety of forces, ranging from human trampling to tank traffic, the data do not allow segregation of differences in recovery rates for different compaction forces. The recovery rate appears to be logarithmic, with the highest rate of change occurring in the first few decades following abandonment. Some higher-elevation sites have completely recovered from soil compaction after 70 years. Using a linear model of recovery, the full recovery time ranges from 92 to 100 years; using a logarithmic model, which asymptotically approaches full recovery, the time required for 85% recovery ranges from 105-124 years.

77 FR 43205 - Notice of Data Availability for Approval, Disapproval and Promulgation of Implementation Plans...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-24

... Haze State Implementation Plan; Federal Implementation Plan for Regional Haze AGENCY: Environmental... (SIP) revision submitted by the State of Wyoming on January 12, 2011, that addresses regional haze...; Regional Haze State Implementation Plan; Federal Implementation Plan for Regional Haze; Proposed Rule (77...

78 FR 28775 - Approval and Promulgation of Implementation Plans; North Carolina; State Implementation Plan...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-16

... Promulgation of Implementation Plans; North Carolina; State Implementation Plan Miscellaneous Revisions AGENCY... a revision to the North Carolina State Implementation Plan submitted on February 3, 2010, through... particulate matter found in the Code of Federal Regulations. In the Final Rules Section of this Federal...

Approved Air Quality Implementation Plans in Region 10

EPA Pesticide Factsheets

Landing page for information about EPA-approved air quality State Implementation Plans (SIPs), Tribal Implementation Plans (TIPs), and Federal Implementation Plans (FIPs) in Alaska, Idaho, Oregon, Washington.

78 FR 69625 - Approval and Promulgation of Implementation Plans; New York State Ozone Implementation Plan Revision

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-20

...] Approval and Promulgation of Implementation Plans; New York State Ozone Implementation Plan Revision AGENCY...) is proposing to approve a revision to the New York State Implementation Plan (SIP) for ozone... air quality standards for ozone. DATES: Comments must be received on or before December 20, 2013...

77 FR 13974 - Approval and Promulgation of Implementation Plans; New York State Ozone Implementation Plan Revision

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-08

... Promulgation of Implementation Plans; New York State Ozone Implementation Plan Revision AGENCY: Environmental... a proposed revision to the New York State Implementation Plan (SIP) for ozone concerning the control... national ambient air quality standards for ozone. DATES: Effective Date: This rule will be effective April...

Mediterranean California, Chapter 13

Treesearch

M.E. Fenn; E.B. Allen; L.H. Geiser

2011-01-01

The Mediterranean California ecoregion (CEC 1997; Fig 2.2) encompasses the greater Central Valley, Sierra foothills, and central coast ranges of California south to Mexico and is bounded by the Pacific Ocean, Sierra Nevada Mountains and Mojave Desert.

A Heavy-Duty Jack for a Giant Task

NASA Image and Video Library

2010-11-03

A major refurbishment of the giant Mars antenna at NASA Deep Space Network Goldstone Deep Space Communications Complex in California Mojave Desert required workers to jack up millions of pounds of delicate scientific equipment.

X-36 in Flight over Mojave Desert

NASA Image and Video Library

1997-10-30

The unusual lines of the X-36 technology demonstrator contrast sharply with the desert floor as the remotely piloted aircraft scoots across the California desert at low altitude during a research flight on October 30, 1997.

Concentrating Solar Power Projects - Solar Electric Generating Station IX |

Science.gov Websites

Station IX (SEGS IX) Country: United States Location: Harper Dry Lake, California (Mojave Desert) Owner(s : Parabolic trough Status: Operational Country: United States City: Harper Dry Lake State: California County

Goldstone 70-Meter

NASA Image and Video Library

2013-12-18

Late night in the desert: Goldstone 230-foot 70-meter antenna tracks spacecraft day and night. This photograph was taken on Jan. 11, 2012. The Goldstone Deep Space Communications Complex is located in the Mojave Desert in California, USA.

Dawn in the Apollo Valley

NASA Image and Video Library

2013-12-18

Beam Wave Guide antennas at Goldstone, known as the Beam Waveguide Cluster. They are located in an area at Goldstone called Apollo Valley. The Goldstone Deep Space Communications Complex is located in the Mojave Desert in California, USA.

Large-Scale Land Development, Fugitive Dust, and Increased Coccidioidomycosis Incidence in the Antelope Valley of California, 1999-2014.

PubMed

Colson, Aaron J; Vredenburgh, Larry; Guevara, Ramon E; Rangel, Natalia P; Kloock, Carl T; Lauer, Antje

2017-06-01

Ongoing large-scale land development for renewable energy projects in the Antelope Valley, located in the Western Mojave Desert, has been blamed for increased fugitive dust emissions and coccidioidomycosis incidence among the general public in recent years. Soil samples were collected at six sites that were destined for solar farm construction and were analyzed for the presence of the soil-borne fungal pathogen Coccidioides immitis which is endemic to many areas of central and southern California. We used a modified culture-independent nested PCR approach to identify the pathogen in all soil samples and also compared the sampling sites in regard to soil physical and chemical parameters, degree of disturbance, and vegetation. Our results indicated the presence of C. immitis at four of the six sites, predominantly in non-disturbed soils of the Pond-Oban complex, which are characterized by an elevated pH and salt bush communities, but also in grassland characterized by different soil parameters and covered with native and non-native annuals. Overall, we were able to detect the pathogen in 40% of the soil samples (n = 42). Incidence of coccidioidomycosis in the Antelope Valley was positively correlated with land use and particulate matter in the air (PM10) (Pearson correlation coefficient >0.5). With the predicted population growth and ongoing large-scale disturbance of soil in the Antelope Valley in coming years, incidence of coccidioidomycosis will likely further increase if policy makers and land developers continue to ignore the risk of grading land without implementing long-term dust mitigation plans in Environmental Impact Reports.

Approved Air Quality Implementation Plans in The Virgin Islands

EPA Pesticide Factsheets

This site contains information about air quality regulations called State Implementation Plans (SIPs), Federal Implementation Plans (FIPs), and Tribal Implementation Plans (TIPs) approved by EPA within the U.S. Virgin Islands.

San Andreas Fault, Southern California, Shaded Relief, Wrapped Color as Height

NASA Image and Video Library

2000-02-17

This topographic map acquired by NASA Shuttle Radar Topography Mission SRTM from data collected on February 16, 2000 vividly displays California famous San Andreas Fault along the southwestern edge of the Mojave Desert, Calif.

Perspective View, Garlock Fault

NASA Image and Video Library

2000-04-20

California Garlock Fault, marking the northwestern boundary of the Mojave Desert, lies at the foot of the mountains, running from the lower right to the top center of this image, which was created with data from NASA shuttle Radar Topography Mission.

San Andreas Fault, Southern California , Radar Image, Wrapped Color as Height

NASA Image and Video Library

2000-02-17

This topographic map acquired by NASA Shuttle Radar Topography Mission SRTM from data collected on February 16, 2000 vividly displays California famous San Andreas Fault along the southwestern edge of the Mojave Desert, Calif.

Watching Test Drives in California for Rover Mission to Mars

NASA Image and Video Library

2012-05-11

Michael Malin, left, principal investigator for three science cameras on NASA Curiosity Mars rover, comments to a news reporter during tests with Curiosity mobility-test stand-in, Scarecrow, on Dumont Dunes in California Mojave Desert.

F-15 ACTIVE in flight

NASA Image and Video Library

1998-04-14

The F-15 ACTIVE in flight above the Mojave desert on April 14, 1998. The overhead shot shows the aircraft's striking red and while paint scheme/ The large forward canards are actually the tail surfaces from an F-18.

Polarization signatures for abandoned agricultural fields in the Manix Basin area of the Mojave Desert

NASA Technical Reports Server (NTRS)

Ray, Terrill W.; Farr, Tom G.; Vanzyl, Jakob J.

1991-01-01

Polarimetric signatures from abandoned circular alfalfa fields in the Manix Basin area of the Mojave desert show systematic changes with length of abandonment. The obliteration of circular planting rows by surface processes could account for the disappearance of bright 'spokes', which seems to be reflection patterns from remnants of the planting rows, with increasing length of abandonment. An observed shift in the location of the maximum L-band copolarization return away from VV, as well as an increase in surface roughness, both occurring with increasing age of abandonment, seems to be attributable to the formation of wind ripple on the relatively vegetationless fields. A Late Pleistocene/Holocene sand bar deposit, which can be identified in the radar images, is probably responsible for the failure of three fields to match the age sequence patterns in roughness and peak shift.

Demographic studies of Joshua trees in Mojave Desert National Parks: demography with emphasis on germination and recruitment

USGS Publications Warehouse

Esque, T.C.; Reynolds, B.; DeFalco, L.A.; Waitman, B.A.; Hughson, Debra

2010-01-01

The study of population change with regard to reproduction, seed dispersal, and germination, establishment, growth, and survival/mortality is known as demography. Demographic studies provide managers with information to assess future trends on the density, distribution, health, and population changes of importance or value, including Joshua trees (Yucca brevifolia). Demographic research provides the potential to understand the combined impacts of climate change and land-use practices and determine if strategies for protecting important species are likely to succeed or fall short of management goals and will identify factors that have the potential to de-stabilize populations outside the realm of natural variation so that management strategies can be developed to circumvent challenges for key species, processes, and ecosystems. The National Park Service and US Geological Survey are collaborating to collect demographic information about the demographics of Joshua tree in the Mojave Desert.

Comparative photosynthetic production of Mojave Desert shrubs. [Ambrosia dumosa, Lycium andersonii, L. pallidum, Larrea tridentata, Krameria parvifolia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bamberg, S.A.; Kleinkopf, G.E.; Wallace, A.

Transpirational and net photosynthetic rates of several species of desert shrubs were measured as a function of season and environmental variables at the Nevada Test Site in the northern Mojave Desert. Drought-deciduous species, Ambrosia dumosa (Grey) Payne, Lycium andersonii Grey, and Lycium pallidum Miers, had higher maximum rates and greater water loss than the evergreen, Larrea tridentata Munz, and summer green, Krameria parvifolia Benth., species. Moisture status was the most critical factor determining gas exchange rates and affected temperature optima and acclimation as the season progressed. Because of a dry spring season, the drought-deciduous species became dormant in late May-earlymore » June; the other two species exhibited by mid-June a small positive CO/sub 2/ uptake during the morning period. Desert plant species, with few exceptions, are extremely labile and exhibit large variability and different adaptive strategies.« less

The Landers earthquake; preliminary instrumental results

USGS Publications Warehouse

Jones, L.; Mori, J.; Hauksson, E.

1992-01-01

Early on the morning of June 28, 1992, millions of people in southern California were awakened by the largest earthquake to occur in the western United States in the past 40 yrs. At 4:58 a.m PDT (local time), faulting associated with the magnitude 7.3 earthquake broke through to earth's surface near the town of Landers, California. the surface rupture then propagated 70km (45 mi) to the north and northwest along a band of faults passing through the middle of the Mojave Desert. Fortunately, the strongest shaking occurred in uninhabited regions of the Mojave Desert. Still one child was killed in Yucca Valley, and about 400 people were injured in the surrounding area. the desert communities of Landers, Yucca Valley, and Joshua Tree in San Bernardino Country suffered considerable damage to buildings and roads. Damage to water and power lines caused problems in many areas. 

Holocene dune formation at Ash Meadows National Wildlife Area, Nevada, USA

USGS Publications Warehouse

Lancaster, Nicholas; Mahan, Shannon

2012-01-01

Small isolated dune fields in the northern Mojave Desert are important centers of biodiversity and archaeological occupation sites. Currently dunes at Ash Meadows, Nevada, are stabilized by vegetation and are experiencing erosion of their upwind margins, indicating a negative sediment budget. New OSL ages from dunes at Ash Meadows indicate continuous eolian accumulation from 1.5 to 0.8 ka, with further accumulation around 0.2 ka. Prior studies (e.g., Mehringer and Warren, 1976) indicate periods of dune accumulation prior to 3.3 ka; 1.9–1 ka; and after 0.9 ka. These periods of eolian accumulation are largely synchronous with those identified elsewhere in the Mojave Desert. The composition of the Ash Meadows dunes indicates their derivation from regional fluvial sources, most likely during periods when axial washes were active as a result of enhanced winter precipitation.

Disturbance and Plant Succession in the Mojave and Sonoran Deserts of the American Southwest

PubMed Central

Abella, Scott R.

2010-01-01

Disturbances such as fire, land clearing, and road building remove vegetation and can have major influences on public health through effects on air quality, aesthetics, recreational opportunities, natural resource availability, and economics. Plant recovery and succession following disturbance are poorly understood in arid lands relative to more temperate regions. This study quantitatively reviewed vegetation reestablishment following a variety of disturbances in the Mojave and Sonoran Deserts of southwestern North America. A total of 47 studies met inclusion criteria for the review. The time estimated by 29 individual studies for full reestablishment of total perennial plant cover was 76 years. Although long, this time was shorter than an estimated 215 years (among 31 individual studies) required for the recovery of species composition typical of undisturbed areas, assuming that recovery remains linear following the longest time since disturbance measurement made by the studies. PMID:20617030

Appropriate Simulants are a Requirement for Mars Surface Systems Technology Development

NASA Technical Reports Server (NTRS)

Edmunson, Jennifer E.; McLemore, Carole A.; Rickman, Douglas L.

2012-01-01

To date, there are two simulants for martian regolith: JSC Mars-1A, produced from palagonitic (weathered) basaltic tephra mined from the Pu'u Nene cinder cone in Hawaii [1] by commercial company Orbitec, and Mojave Mars Simulant (MMS), produced from Saddleback Basalt in the western Mojave desert by the Jet Propulsion Laboratory [2]. Until numerous recent orbiters, rovers, and landers were sent to Mars, weathered basalt was surmised to cover every inch of the martian landscape. All missions since Viking have disproven that the entire martian surface is weathered basalt. In fact, the outcrops, features, and surfaces that are significantly different from weathered basalt are too numerous to realistically count. There are gullies, evaporites, sand dunes, lake deposits, hydrothermal deposits, alluvium, etc. that indicate sedimentary and chemical processes. There is no one size fits all simulant. Each unique area requires its own simulant in order to test technologies and hardware, thereby reducing risk.

ARC-2007-ACD07-0056-077

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/ shown here are Dr Chris McKay and Monika Kress, Professor of Astronomy at San Jose State University

ARC-2007-ACD07-0056-072

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/ shown here are Dr Chris McKay and Monika Kress, Professor of Astronomy at San Jose State University

ARC-2007-ACD07-0056-073

NASA Image and Video Library

2007-03-26

Spaceward Bound event in the Mojave Deser , CA (an outreach exercise) with Dr Chris McKay and Ames Education department personnel Brian Day, Barbara Bazar and a accompaning (learning for the the classroom) team of teachers will be studying side-by-side with NASA scientists who search for life in extreme environments, closely approximating what they expect to find on other planets. Why the Mojave -- an inhospitable, sun-drenched spot in the California Desert? This natural setting presents scientists with opportunities to study environments that are analogous to what explorers will find on the Moon and Mars. Teachers and scientists will perform scientific fieldwork in lunar geology, Mars astrobiology, Mars geology, and issues of temperature and solar inundation and radiation. for additional information and Outreach projects see http://quest.arc.nasa.gov/ shown here are Dr Chris McKay and Monika Kress, Professor of Astronomy at San Jose State University

Airborne radioactivity surveys in the Mojave Desert region, Kern, Riverside, and San Bernardino Counties, California

USGS Publications Warehouse

Moxham, Robert M.

1952-01-01

Airborne radioactivity surveys in the Mojave Desert region Kern, Riverside, and Bernardino counties were made in five areas recommended as favorable for the occurrence of radioactive raw materials: (1) Rock Corral area, San Bernardino County. (2) Searles Station area, Kern county. (3) Soledad area, Kern County. (4) White Tank area, Riverside and San Bernardino counties. (5) Harvard Hills area, San Bernardino County. Anomalous radiation was detected in all but the Harvard Hills area. The radioactivity anomalies detected in the Rock Corral area are of the greatest amplitude yet recorded by the airborne equipment over natural sources. The activity is apparently attributable to the thorium-beating mineral associated with roof pendants of crystalline metamorphic rocks in a granitic intrusive. In the Searles Station, Soledad, and White Tank area, several radioactivity anomalies of medium amplitude were recorded, suggesting possible local concentrations of radioactive minerals.

Mojave Desert, California

NASA Image and Video Library

1973-06-22

SL2-03-126 (June 1973) --- A color infrared photograph of the Los Angeles County and Kern County area, taken from the Skylab space station in Earth orbit during its first manned Skylab mission. The Mojave Desert occupies the northeast one-fourth of the photograph. Lake Isabella in the Sierra Nevada Mountains is the v-shaped body of water. The San Gabriel Mountains extend across the southern part of the picture. At lower center is the intersection of the San Andreas and Garlock faults. The San Joaquin Valley is in the center at the left edge. (The picture should be held with the heavy cloud cover at lower right corner so that north will be at top.) This picture was exposed by one of the six lenses of the Itek-furnished S190-A Multispectral Photographic Facility experiment in the Multiple Docking Adapter of the Skylab space station. Type 2443 film was used. Photo credit: NASA

77 FR 48061 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Regional Haze State...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-13

... Promulgation of Air Quality Implementation Plans; Pennsylvania; Regional Haze State Implementation Plan...'s limited approval of Pennsylvania's Regional Haze State Implementation Plan (SIP). DATES: Effective... announcing our limited approval of Pennsylvania's Regional Haze SIP. In this document, we inadvertently...

Landscape genetic approaches to guide native plant restoration in the Mojave Desert

USGS Publications Warehouse

Shryock, Daniel F.; Havrilla, Caroline A.; DeFalco, Lesley; Esque, Todd C.; Custer, Nathan; Wood, Troy E.

2016-01-01

Restoring dryland ecosystems is a global challenge due to synergistic drivers of disturbance coupled with unpredictable environmental conditions. Dryland plant species have evolved complex life-history strategies to cope with fluctuating resources and climatic extremes. Although rarely quantified, local adaptation is likely widespread among these species and potentially influences restoration outcomes. The common practice of reintroducing propagules to restore dryland ecosystems, often across large spatial scales, compels evaluation of adaptive divergence within these species. Such evaluations are critical to understanding the consequences of large-scale manipulation of gene flow and to predicting success of restoration efforts. However, genetic information for species of interest can be difficult and expensive to obtain through traditional common garden experiments. Recent advances in landscape genetics offer marker-based approaches for identifying environmental drivers of adaptive genetic variability in non-model species, but tools are still needed to link these approaches with practical aspects of ecological restoration. Here, we combine spatially-explicit landscape genetics models with flexible visualization tools to demonstrate how cost-effective evaluations of adaptive genetic divergence can facilitate implementation of different seed sourcing strategies in ecological restoration. We apply these methods to Amplified Fragment Length Polymorphism (AFLP) markers genotyped in two Mojave Desert shrub species of high restoration importance: the long-lived, wind-pollinated gymnosperm Ephedra nevadensis, and the short-lived, insect-pollinated angiosperm Sphaeralcea ambigua. Mean annual temperature was identified as an important driver of adaptive genetic divergence for both species. Ephedra showed stronger adaptive divergence with respect to precipitation variability, while temperature variability and precipitation averages explained a larger fraction of adaptive divergence in Sphaeralcea. We describe multivariate statistical approaches for interpolating spatial patterns of adaptive divergence while accounting for potential bias due to neutral genetic structure. Through a spatial bootstrapping procedure, we also visualize patterns in the magnitude of model uncertainty. Finally, we introduce an interactive, distance-based mapping approach that explicitly links marker-based models of adaptive divergence with local or admixture seed sourcing strategies, promoting effective native plant restoration.

Is there room for all of us? Renewable energy and Xerospermophilus mohavensis

USGS Publications Warehouse

Inman, Richard D.; Esque, Todd C.; Nussear, Kenneth E.; Leitner, Philip; Matocq, Marjorie D.; Weisberg, Peter J.; Dilts, Tomas E.; Vandergast, Amy G.

2013-01-01

Mohave ground squirrels Xerospermophilus mohavensis Merriam are small ground-dwelling rodents that have a highly restricted range in the northwest Mojave Desert, California, USA. Their small natural range is further reduced by habitat loss from agriculture, urban development, military training and recreational activities. Development of wind and solar resources for renewable energy has the potential to further reduce existing habitat. We used maximum entropy habitat models with observation data to describe current potential habitat in the context of future renewable energy development in the region. While 16% of historic habitat has been impacted by, or lost to, urbanization at present, an additional 10% may be affected by renewable energy development in the near future. Our models show that X. mohavensis habitat suitability is higher in areas slated for renewable energy development than in surrounding areas. We provide habitat maps that can be used to develop sampling designs, evaluate conservation corridors and inform development planning in the region.

Monazite paragenesis and U-Pb systematics in rocks of the eastern Mojave Desert, California, U.S.A.: implications for thermochronometry

USGS Publications Warehouse

Kingsbury, J.A.; Miller, C.F.; Wooden, J.L.; Harrison, T.M.

1993-01-01

Studies of the paragenesis and U-Pb systematics of monazite in rocks from the eastern Mojave Desert, California, corroborate its potential usefulness as a prograde thermochronometer and in dating granite inheritance. Unmetamorphosed Latham Shale and its equivalents at grades ranging from greenschist to upper amphibolite facies are virtually identical in composition. Monazite is absent in the shale and low-grade schists, but it is abundant in schists at staurolite and higher grades. Lower-grade schists instead include minute Th- and Ce-oxides and unidentified Ce-poor LREE-phosphates that apparently are lower-temperature precursors to monazite. Thus monazite originates when the pelite passes through lower-amphibolite-facies conditions. Monazites from three Upper Cretaceous granites yield ages that are strongly discordant. Upper intercepts of 1.6-1.7 Ga are similar to those defined by U-Pb data for coexisting zircons and coincide with a period of copious magmatism in the Mojave crust. As the host Upper Cretaceous granitic magmas were all above 700??C, effective closure of the restitic monazites to Pb loss must be well in excess of this temperature. U-Pb compositions of monazite from Proterozoic granitoids and schist also indicate high Pb retentivity. Taken together, these studies support the suggestion that monazite can be an effective prograde thermochronometer. At least in pelites, it is not usually retained as a detrital mineral, but rather forms during moderate-temperature metamorphism. Its U-Pb system should not be reset by subsequent higher-grade metamorphism. ?? 1993.

Comparative analysis of cyanobacteria inhabiting rocks with different light transmittance in the Mojave Desert: a Mars terrestrial analogue

NASA Astrophysics Data System (ADS)

Smith, Heather D.; Baqué, Mickael; Duncan, Andrew G.; Lloyd, Christopher R.; McKay, Christopher P.; Billi, Daniela

2014-05-01

The Mojave Desert has been long considered a suitable terrestrial analogue to Mars in many geological and astrobiological aspects. The Silver Lake region in the Mojave Desert hosts several different rock types (talc, marble, quartz, white carbonate and red-coated carbonate) colonized by hypoliths within a few kilometres. This provides an opportunity to investigate the effect of rock type on hypolithic colonization in a given environment. Transmission measurements from 300 to 800 nm showed that the transmission of blue and UVA varied between rock types. The wavelength at which the transmission fell to 1% of the transmission at 600 nm was 475 nm for white carbonate and quartz, 425 nm for red-coated carbonate and talc and 380 nm for marble. The comparative analysis of the cyanobacterial component of hypoliths under different rocks, as revealed by sequencing 16S rRNA gene clone libraries, showed no significant variation with rock type; hypoliths were dominated by phylotypes of the genus Chroococcidiopsis, although less abundant phylotypes of the genus Loriellopsis, Leptolyngbya and Scytonema occurred. The comparison of the confocal laser scanning microscopy-λ (CLSM-λ) scan analysis of the spectral emission of the photosynthetic pigments of Chroococcidiopsis in different rocks with the spectrum of isolated Chroococcidiopsis sp. 029, revealed a 10 nm red shift in the emission fingerprinting for quartz and carbonate and a 5 nm red shift for talc samples. This result reflects the versatility of Chroococcidiopsis in inhabiting dry niches with different light availability for photosynthesis.

Ectoparasites of Microtus californicus and Possible Emergence of an Exotic Ixodes Species Tick in California.

PubMed

Poulsen, Amanda; Conroy, Chris; Foley, Patrick; Ott-Conn, Caitlin; Roy, Austin; Brown, Richard; Foley, Janet

2015-09-01

California voles (Microtus californicus Peale) harbor fleas and ticks, may be infected with vector-borne pathogens, and could themselves suffer from disease and serve as a source of infection for people and other animals. Here we summarize publications, museum archives, and recent records of ticks and fleas from California voles. There have been 18 flea species reported on California voles with geographic locations reported for 13. During recent statewide surveys, we found six flea species, with the highest species richness in Humboldt County. We found three of five previously reported tick species as well as a tick resembling the eastern North American tick Ixodes minor Neumann (which we here designate Ixodes "Mojave morphotype") on isolated Amargosa voles and Owens Valley voles (Microtus californicus vallicola Bailey) in Inyo County in 2012 and 2014. Additional incidental observations of this Mojave morphotype tick were on a western harvest mouse (Reithrodontomys megalotis Baird) at the Mojave site and a montane vole (Microtus montanus Peale) in the Owens Valley, both in March, 2014. We cannot rule out that this tick species has been present in remote areas of California but gone unrecognized, but these data are consistent with recent introduction of this tick, possibly from migrating birds. Changes in the ectoparasite fauna suggest changing ecologies of vectors and vector-borne pathogens that could influence animals and people as well. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The Mojave Desert: A Martian Analog Site for Future Astrobiology Themed Missions

NASA Technical Reports Server (NTRS)

Salas, E.; Abbey, W.; Bhartia, R.; Beegle, L. W.

2011-01-01

Astrobiological interest in Mars is highlighted by evidence that Mars was once warm enough to have liquid water present on its surface long enough to create geologic formations that could only exist in the presense of extended fluvial periods. These periods existed at the same time life on Earth arose. If life began on Mars as well during this period, it is reasonable to assume it may have adapted to the subsurface as environments at the surface changed into the inhospitable state we find today. If the next series of Mars missions (Mars Science Laboratory, the ExoMars Trace Gas Orbiter proposed for launch in 2016, and potential near surface sample return) fail to discover either extinct or extant life on Mars, a subsurface mission would be necessary to attempt to "close the book" on the existence of martian life. Mars is much colder and drier than Earth, with a very low pressure CO2 environment and no obvious habitats. Terrestrial regions with limited precipitation, and hence reduced active biota, are some of the best martian low to mid latitude analogs to be found on Earth, be they the Antarctic dry valleys, the Atacama or Mojave Deserts. The Mojave Desert/Death Valley region is considered a Mars analog site by the Terrestrial Analogs Panel of the NSF-sponsored decadal survey; a field guide was even developed and a workshop was held on its applicability as a Mars analog. This region has received a great deal of attention due to its accessibility and the variety of landforms and processes observed relevant to martian studies.

The effect of cactus spines on light interception and Photosystem II for three sympatric species of Opuntia from the Mojave Desert.

PubMed

Loik, Michael E

2008-09-01

Cactus spines reduce herbivory, direct water toward roots and reduce the impacts of high- and low-temperature extremes. Yet, shading of stems by spines reduces incident photosynthetic photon flux density (PFD), photosynthesis and growth. This study compared spinescence, PFD interception, stem temperature, Photosystem II (PSII) photochemistry and xanthophyll pigment composition for three species of cacti from the Mojave Desert, CA. The species vary in spinescence: Opuntia basilaris, which has no central or radial spines; Opuntia erinacea, which is densely covered with spines; and Opuntia phaeacantha, which has an intermediate coverage of spines. The role of spines was tested by removing spines from stems of O. erinacea. PFD interception was similar for both O. basilaris and O. phaeacantha, and about three times that for densely spined O. erinacea; removal of spines increased incident PFD three-fold. There were no effects of spines on stem temperatures. Steady-state light-response curves of chlorophyll a fluorescence from PSII indicated that PhiPSII, photochemical quenching (qP) and electron flux within PSII were lower, and non-photochemical quenching was higher, for O. erinacea in comparison to the other two species with less spines. After 2 months, qP was higher and electron flux lower, and xanthophyll pigment pool size was higher, for stems from which spines had been removed compared with intact stems. These three species allocate different amounts of biomass to spines, resulting in species-specific PFD interception, PSII photochemistry and xanthophyll pigment pool size, which may help maintain rates of photosynthesis during the hot, dry Mojave Desert summer.

Soil-geomorphic significance of land surface characteristics in an arid mountain range, Mojave Desert, USA

USGS Publications Warehouse

Hirmas, D.R.; Graham, R.C.; Kendrick, K.J.

2011-01-01

Mountains comprise an extensive and visually prominent portion of the landscape in the Mojave Desert, California. Landform surface properties influence the role these mountains have in geomorphic processes such as dust flux and surface hydrology across the region. The primary goal of this study was to describe and quantify land surface properties of arid-mountain landforms as a step toward unraveling the role these properties have in soil-geomorphic processes. As part of a larger soil-geomorphic study, four major landform types were identified within the southern Fry Mountains in the southwestern Mojave Desert on the basis of topography and landscape position: mountaintop, mountainflank, mountainflat (intra-range low-relief surface), and mountainbase. A suite of rock, vegetation, and morphometric land surface characteristic variables was measured at each of 65 locations across the study area, which included an associated piedmont and playa. Our findings show that despite the variation within types, landforms have distinct land surface properties that likely control soil-geomorphic processes. We hypothesize that surface expression influences a feedback process at this site where water transports sediment to low lying areas on the landscape and wind carries dust and soluble salts to the mountains where they are washed between rocks, incorporated into the soil, and retained as relatively long-term storage. Recent land-based video and satellite photographs of the dust cloud emanating from the Sierra Cucapá Mountains in response to the 7.2-magnitude earthquake near Mexicali, Mexico, support the hypothesis that these landforms are massive repositories of dust.

Attempt of Serendipitous Science During the Mojave Volatile Prospector Field Expedition

NASA Technical Reports Server (NTRS)

Roush, T. L.; Colaprete, A.; Heldmann, J.; Lim, D. S. S.; Cook, A.; Elphic, R.; Deans, M.; Fluckiger, L.; Fritzler, E.; Hunt, David

2015-01-01

On 23 October a partial solar eclipse occurred across parts of the southwest United States between approximately 21:09 and 23:40 (UT), with maximum obscuration, 36%, occurring at 22:29 (UT). During 21-26 October 2014 the Mojave Volatile Prospector (MVP) field expedition deployed and operated the NASA Ames Krex2 rover in the Mojave desert west of Baker, California (Fig. 1, bottom). The MVP field expedition primary goal was to characterize the surface and sub-surface soil moisture properties within desert alluvial fans, and as a secondary goal to provide mission operations simulations of the Resource Prospector (RP) mission to a Lunar pole. The partial solar eclipse provided an opportunity during MVP operations to address serendipitous science. Science instruments on Krex2 included a neutron spectrometer, a near-infrared spectrometer with associated imaging camera, and an independent camera coupled with software to characterize the surface textures of the areas encountered. All of these devices are focused upon the surface and as a result are downward looking. In addition to these science instruments, two hazard cameras are mounted on Krex2. The chief device used to monitor the partial solar eclipse was the engineering development unit of the Near-Infrared Volatile Spectrometer System (NIRVSS) near-infrared spectrometer. This device uses two separate fiber optic fed Hadamard transform spectrometers. The short-wave and long-wave spectrometers measure the 1600-2400 and 2300-3400 nm wavelength regions with resolutions of 10 and 13 nm, respectively. Data are obtained approximately every 8 seconds. The NIRVSS stares in the opposite direction as the front Krex2.

77 FR 5191 - Approval and Promulgation of Air Quality Implementation Plans; District of Columbia; Regional...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-02

... Promulgation of Air Quality Implementation Plans; District of Columbia; Regional Haze State Implementation Plan... of Columbia Regional Haze Plan, a revision to the District of Columbia State Implementation Plan (SIP... existing anthropogenic impairment of visibility in mandatory Class I areas through a regional haze program...

40 CFR 52.222 - Negative declarations.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Mojave Desert Air Quality Management District. (i) Natural Gas and Gasoline Processing Equipment and...) Sacramento Metropolitan Air Quality Management District. (i) Plastic Parts Coating: Business Machines and...) Sacramento Metropolitan Air Quality Management District. (i) Nitric and Adipic Acid Manufacturing Plants...

ERAST Program Proteus Aircraft in Flight

NASA Image and Video Library

1999-07-26

The unusual design of the Proteus high-altitude aircraft, incorporating a gull-wing shape for its main wing and a long, slender forward canard, is clearly visible in this view of the aircraft in flight over the Mojave Desert in California.

Crystals May Have Formed in Drying Martian Lake

NASA Image and Video Library

2014-12-08

Lozenge-shaped crystals are evident in this magnified view of a Martian rock target called Mojave, taken on Nov. 15, 2014, by NASA Curiosity Mars rover. These features record concentration of dissolved salts, possibly in a drying lake.

A Raman Spectroscopic Study of Samples from the May 2001 FIDO Test Site

NASA Technical Reports Server (NTRS)

Kuebler, K.; Jolliff, B. L.; Wang, A.; Haskin, L. A.

2002-01-01

Last May, a rover field test was conducted in the Mojave desert. This study shows what mineralogy a rover-deployed Raman spectrometer might have observed. Additional information is contained in the original extended abstract.

Space Radar Image of Colorado River

NASA Image and Video Library

1999-04-15

This space radar image illustrates the recent rapid urban development occurring along the lower Colorado River at the Nevada/Arizona state line. Lake Mojave is the dark feature that occupies the river valley in the upper half of the image.

Post-earthquake relaxation evidence for laterally variable viscoelastic structure and elevated water concentration in the southwestern California mantle

NASA Astrophysics Data System (ADS)

Pollitz, F. F.

2014-12-01

I re-examine the lower crust and mantle relaxation following two large events in the Mojave Desert: the 1992 M7.3 Landers and 1999 M7.1 Hector Mine, California, earthquakes. More than a decade of GPS time series from regional sites out to 250 km from the ruptures are used to constrain models of postseismic relaxation. Crustal motions in the Mojave Desert region are elevated for several years following each event, with perturbations from a pre-Landers background of order mm to cm per year. I consider afterslip and relaxation of the ductile lower crust and mantle to explain these motions. To account for broad scale relaxation, the Burgers body model is employed, involving Kelvin (transient) viscosity and rigidity and Maxwell (steady state) viscosity and rigidity. I use the code VISCO2.5D to perform 2.5D modeling of the postseismic relaxation (3D quasi-static motions computed on 2D, laterally heterogeneous viscoelastic structures; Pollitz, 2014 GJI). Joint afterslip / postseismic relaxation modeling of continuous GPS time series up to 10.46 years following the Hector Mine earthquake (i.e. up to the time of the 2010 M7.2 El Mayor-Cucapah earthquake) reveals that a northwest-trending `southwest domain' that envelopes the San Andreas fault system and western Mojave Desert has ~4 times larger Maxwell mantle viscosity than the adjacent `northeast domain' that extends inland and envelopes the Landers and Hector Mine rupture areas in the central Mojave Desert. This pattern is counter to that expected from regional heat flow, which is higher in the northeast domain, but it is explicable by means of a non-linear rheology that includes dependence on both strain rate and water concentration. I infer that the southwest domain mantle has a relatively low steady-state viscosity because of its high strain rate and water content. The relatively low mantle water content of the northeast domain is interpreted to result from the continual extraction of water through igneous and volcanic activity over the past ~20 Myr. The inference of Maxwellian viscosities is possible because the material relaxation times involved (5 years and 20 years for the SW and NE domains, respectively) are to a large extent spanned by the decade of available post-Hector Mine observations.

Surficial geology and stratigraphy of Pleistocene Lake Manix, San Bernardino County, California

USGS Publications Warehouse

Reheis, Marith C.; Redwine, Joanna R.; Wan, Elmira; McGeehin, John P.; VanSistine, D. Paco

2014-01-01

Pluvial Lake Manix and its surrounding drainage basin, in the central Mojave Desert of California, has been a focus of paleoclimate, surficial processes, and neotectonic studies by the U.S. Geological Survey (USGS) since about 2004. The USGS initiated studies of Lake Manix deposits to improve understanding of the paleoclimatic record and the shifts in atmospheric circulation that controlled precipitation in the Mojave Desert. Until approximately 25,000 years ago, Lake Manix was the terminus of the Mojave River, which drains northeasterly from the San Bernardino Mountains; the river currently terminates in the Soda Lake and Silver Lake playas. Pleistocene Lake Manix occupied several subbasins at its maximum extent. This map focuses on the extensive exposures created by incision of the Mojave River and its tributaries into the interbedded lacustrine and alluvial deposits within the central (Cady) and northeastern (Afton) subbasins of Lake Manix, and extends from the head of Afton Canyon to Manix Wash. The map illuminates the geomorphic development and depositional history of the lake and alluvial fans within the active tectonic setting of the eastern California shear zone, especially interactions with the left-lateral Manix fault. Lake Manix left an extraordinarily detailed but complex record of numerous transgressive-regressive sequences separated by desiccation and deposition of fan, eolian, and fluvial deposits, and punctuated by tectonic movements and a catastrophic flood that reconfigured the lake basin. Through careful observation of the intercalated lacustrine and fan sequences and by determining the precise elevations of unit contacts, this record was decoded to understand the response of the lake and river system to the interplay of climatic, geomorphic, and tectonic forces. These deposits are exposed in steep badland topography. Mapping was carried out mostly at scales of 1:12,000, although the map is presented at 1:24,000 scale, and employs custom unit nomenclature, with multiple subdivided lacustrine and alluvial fan units. In addition, many important units are very thin and cannot be mapped separately, or are covered by thin eolian sand, so these are commonly portrayed as stacks of units or combined units. These details are more accurately portrayed in the measured sections that accompany the map. Altitudes of many contacts were obtained using differentially corrected Global Positioning System (GPS) or, in some cases, lidar (light detection and ranging) data.

Measuring Dust Emission from the Mojave Desert (USA) by Daily Remote-Camera Observations and Wind-Erosion Measurements: Bearing on "Unseen" Sources and Global Dust Abundance

NASA Astrophysics Data System (ADS)

Reynolds, R. L.; Urban, F.; Goldstein, H. L.; Fulton, R.

2017-12-01

A large gap in understanding the effects of atmospheric dust at all spatial scales is uncertainty about how much and whence dust is emitted annually. Digital recording of dust emission at high spatial and temporal resolution would, together with periodic flux measurements, support improved estimates of local-scale dust flux where infrastructure could support remote internet enabled cameras. Such recording would also elucidate wind-erosion dynamics when combined with meteorological data. Remote camera recording of dust-emitting settings on and around Soda Lake (Mojave Desert) was conducted every 15 minutes during daylight between 10 Nov. 2010 and 31 Dec. 2016 and images uploaded to a web server. Examination of 135,000 images revealed frequent dust events, termed "dust days" when plumes obscured mountains beyond source areas. Such days averaged 68 (sd=10) per year (2011 through 2016). We examined satellite retrievals (MODIS, GOES) for dust events during six cloudless days of highest and longest duration dust emission but none were observed. From Apr. 2000 through May 2013, aeolian sediments collected at three sites were sampled and weighed. Estimates of the emitted mass of silt- and clay-size fractions were made on the basis of measured horizontal mass flux, particle sizes of sediment in collectors, and roughly determined areas of dust generation. Over this period, nearly 4 Tg yr-1 of dust (as particulate matter <63 micrometers) were emitted across the study area. Much higher rates (about 7 Tg yr-1) were estimated for a subset period from Jan. 2011 through May 2013 following a major Mojave River flood in the basin in late Dec. 2010 that deposited flood sediment across the lake basin. Increased emission was likely related to the availability of fresh, unanchored flood sediment. Within the Mojave and Great Basin deserts of North America, many settings akin to those at Soda Lake similarly emit dust that is rarely detected in satellite retrievals. These findings strongly imply that local and regional dust emissions from western North America are far underestimated and that, by extension to relatively small dust-source areas across all drylands, global dust emissions may also be underestimated.

A swirling jet in the quasar 1308+326

NASA Astrophysics Data System (ADS)

Britzen, S.; Qian, S.-J.; Steffen, W.; Kun, E.; Karouzos, M.; Gergely, L.; Schmidt, J.; Aller, M.; Aller, H.; Krause, M.; Fendt, C.; Böttcher, M.; Witzel, A.; Eckart, A.; Moser, L.

2017-06-01

Context. Despite numerous and detailed studies of the jets of active galactic nuclei (AGN) on pc-scales, many questions are still debated. The physical nature of the jet components is one of the most prominent unsolved problems, as is the launching mechanism of jets in AGN. The quasar 1308+326 (z = 0.997) allows us to study the overall properties of its jet in detail and to derive a more physical understanding of the nature and origin of jets in general. The long-term data provided by the Monitoring Of Jets in Active galactic nuclei with Very Long Baseline Array (VLBA) experiments (MOJAVE) survey permit us to trace out the structural changes in 1308+326 that we present here. The long-lived jet features in this source can be followed for about two decades. Aims: We investigate the very long baseline interferomety (VLBI) morphology and kinematics of the jet of 1308+326 to understand the physical nature of this jet and jets in general, the role of magnetic fields, and the causal connection between jet features and the launching process. Methods: Fifty VLBA observations performed at 15 GHz from the MOJAVE survey were re-modeled with Gaussian components and re-analyzed (the time covered: 20 Jan. 1995-25 Jan. 2014). The analysis was supplemented by multi-wavelength radio-data (UMRAO, at 4.8, 8.0, and 14.5 GHz) in polarization and total intensity. We fit the apparent motion of the jet features with the help of a model of a precessing nozzle. Results: The jet features seem to be emitted with varying viewing angles and launched into an ejection cone. Tracing the component paths yields evidence for rotational motion. Radio flux-density variability can be explained as a consequence of enhanced Doppler boosting corresponding to the motion of the jet relative to the line of sight. Based on the presented kinematics and other indicators, such as electric-vector polarization position-angle (EVPA) rotation, we conclude that the jet of 1308+326 has a helical structure, meaning that the components are moving along helical trajectories and the trajectories themselves are also experiencing a precessing motion. A model of a precessing nozzle was applied to the data and a subset of the observed jet feature paths can be modeled successfully within this model. The data till 2012 are consistent with a swing period of 16.9 yr. We discuss several scenarios to explain the observed motion phenomena, including a binary black hole model. It seems unlikely that the accretion disk around the primary black hole, which is disturbed by the tidal forces of the secondary black hole, is able to launch a persistent axisymmetric jet. Conclusions: We conclude that we are observing a rotating helix. In particular, the observed EVPA swings can be explained by a shock moving through a straight jet that is pervaded by a helical magnetic field. We compare our results for 1308+326 with other astrophysical scenarios where similar, wound-up filamentary structures are found. They are all related to accretion-driven processes. A helically moving or wound up object is often explained by filamentary features moving along magnetic field lines of magnetic flux tubes. It seems that a "component" comprises plasma tracing the magnetic field, which guides the motion of the radiating radio-band plasma. Further investigations and modeling are in preparation. The reduced Figs. A.1-A.13 (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/602/A29 http://www.physics.purdue.edu/astro/MOJAVE/ http://www.physics.purdue.edu/astro/MOJAVE/ http://www.physics.purdue.edu/astro/MOJAVE/animated/1308+326.I.mpg http://www.physics.purdue.edu/MOJAVE/sourcepages/1308+326.shtml

24 CFR 598.605 - Implementation plan.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 24 Housing and Urban Development 3 2014-04-01 2013-04-01 true Implementation plan. 598.605 Section 598.605 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... Grants § 598.605 Implementation plan. (a) Implementation plan content. An EZ must submit an...

77 FR 41279 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Regional Haze State...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-13

... Promulgation of Air Quality Implementation Plans; Pennsylvania; Regional Haze State Implementation Plan AGENCY... the Regional Haze State Implementation Plan (SIP) (hereafter RH SIP) revision submitted by the... anthropogenic impairment of visibility in mandatory Class I areas [[Page 41280

76 FR 12945 - Instructions for Implementing Climate Change Adaptation Planning in Accordance With Executive...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-09

... COUNCIL ON ENVIRONMENTAL QUALITY Instructions for Implementing Climate Change Adaptation Planning... Availability of Climate Change Adaptation Planning Implementing Instructions. SUMMARY: The Chair of the Council... for Implementing Climate Change Adaptation Planning are now available at: http://www.whitehouse.gov...

40 CFR 52.672 - Approval of plans.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Idaho § 52.672 Approval of plans. (a) Carbon Monoxide. (1) EPA approves as a revision to the Idaho State Implementation Plan, the Limited Maintenance Plan for.... [Reserved] (e) Particulate Matter. (1) EPA approves as a revision to the Idaho State Implementation Plan...

78 FR 17835 - Approval and Promulgation of Federal Implementation Plan for Oil and Natural Gas Well Production...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-22

...The EPA is taking final action to promulgate a Reservation- specific Federal Implementation Plan in order to regulate emissions from oil and natural gas production facilities located on the Fort Berthold Indian Reservation in North Dakota. The Federal Implementation Plan includes basic air quality regulations for the protection of communities in and adjacent to the Fort Berthold Indian Reservation. The Federal Implementation Plan requires owners and operators of oil and natural gas production facilities to reduce emissions of volatile organic compounds emanating from well completions, recompletions, and production and storage operations. This Federal Implementation Plan will be implemented by the EPA, or a delegated tribal authority, until replaced by a Tribal Implementation Plan. The EPA proposed a Reservation-specific Federal Implementation Plan concurrently with an interim final rule on August 15, 2012. This final Federal Implementation Plan replaces the interim final rule in all intents and purposes on the effective date of the final rule. The EPA is taking this action pursuant to the Clean Air Act (CAA).

Mojave National Preserve Boundary Adjustment Act of 2014

THOMAS, 113th Congress

Sen. Heller, Dean [R-NV

2014-05-20

Senate - 07/23/2014 Committee on Energy and Natural Resources Senate Subcommittee on National Parks. Hearings held. With printed Hearing: S.Hrg. 113-493. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Modeling Agassiz's Desert Tortoise Population Response to Anthropogenic Stressors

EPA Science Inventory

Mojave Desert tortoise (Gopherus agassizii) populations are exposed to a variety of anthropogenic threats, which vary in nature, severity, and frequency. Tortoise management in conservation areas can be compromised when the relative importance of these threats is not well underst...

67. FIRST AND SECOND AQUEDUCTS GOING UNDERGROUND PARALLEL TO DIRT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

67. FIRST AND SECOND AQUEDUCTS GOING UNDERGROUND PARALLEL TO DIRT ROADS, MOJAVE DESERT LOOKING NORTH - Los Angeles Aqueduct, From Lee Vining Intake (Mammoth Lakes) to Van Norman Reservoir Complex (San Fernando Valley), Los Angeles, Los Angeles County, CA

70m Antenna at Goldstone, California

NASA Image and Video Library

2008-07-06

Night shot of the 70m antenna at Goldstone, California. The parabolic dish is 70m 230 ft. in diameter. The Goldstone Deep Space Communications Complex, located in the Mojave Desert in California, is one of three complexes which comprise NASA DSN.

24 CFR 598.605 - Implementation plan.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 24 Housing and Urban Development 3 2012-04-01 2012-04-01 false Implementation plan. 598.605 Section 598.605 Housing and Urban Development Regulations Relating to Housing and Urban Development... Empowerment Zone Grants § 598.605 Implementation plan. (a) Implementation plan content. An EZ must submit an...

24 CFR 598.605 - Implementation plan.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 24 Housing and Urban Development 3 2013-04-01 2013-04-01 false Implementation plan. 598.605 Section 598.605 Housing and Urban Development Regulations Relating to Housing and Urban Development... Empowerment Zone Grants § 598.605 Implementation plan. (a) Implementation plan content. An EZ must submit an...

78 FR 68005 - Approval and Promulgation of Implementation Plans; Mississippi; Transportation Conformity SIP...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-13

... this Federal Register, EPA is approving the State's implementation plan revision as a direct final rule...] Approval and Promulgation of Implementation Plans; Mississippi; Transportation Conformity SIP--Memorandum... proposing to approve a State Implementation Plan revision submitted by the Mississippi Department of...

Effective protection of open space: does planning matter?

PubMed

Steelman, Toddi A; Hess, George R

2009-07-01

High quality plans are considered a crucial part of good land use planning and often used as a proxy measure for success in plan implementation and goal attainment. We explored the relationship of open space plan quality to the implementation of open space plans and attainment of open space protection goals in Research Triangle, North Carolina, USA. To measure plan quality, we used a standard plan evaluation matrix that we modified to focus on open space plans. We evaluated all open space plans in the region that contained a natural resource protection element. To measure plan implementation and open space protection, we developed an online survey and administered it to open space planners charged with implementing the plans. The survey elicited each planner's perspective on aspects of open space protection in his or her organization. The empirical results (1) indicate that success in implementation and attaining goals are not related to plan quality, (2) highlight the importance of when and how stakeholders are involved in planning and implementation processes, and (3) raise questions about the relationship of planning to implementation. These results suggest that a technically excellent plan does not guarantee the long-term relationships among local land owners, political and appointed officials, and other organizations that are crucial to meeting land protection goals. A greater balance of attention to the entire decision process and building relationships might lead to more success in protecting open space.

78 FR 41731 - Source Specific Federal Implementation Plan for Implementing Best Available Retrofit Technology...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-11

... Federal Implementation Plan for Implementing Best Available Retrofit Technology for Four Corners Power... Implementation Plan (FIP) to implement the Best Available Retrofit Technology (BART) requirement of the Regional... given the uncertainties in the electrical market in Arizona, EPA is proposing to extend the date by...

78 FR 40654 - Approval, Disapproval and Promulgation of Implementation Plans; State of Wyoming; Regional Haze...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-08

..., Disapproval and Promulgation of Implementation Plans; State of Wyoming; Regional Haze State Implementation Plan; Federal Implementation Plan for Regional Haze; Notice of Public Hearings AGENCY: Environmental...) addressing regional haze under. We are making this change in response to letters submitted by the Governor of...

78 FR 78310 - Approval and Promulgation of Implementation Plans; North Carolina; Transportation Conformity...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-26

... Federal Register, EPA is approving the State's implementation plan revision as a direct final rule without...] Approval and Promulgation of Implementation Plans; North Carolina; Transportation Conformity Memorandum of... Implementation Plan submitted on July 12, 2013, through the North Carolina Department of Environment and Natural...

77 FR 58072 - Finding of Substantial Inadequacy of Implementation Plan; Call for California State...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-19

... Substantial Inadequacy of Implementation Plan; Call for California State Implementation Plan Revision; South Coast AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: In response to a... that the California State Implementation Plan (SIP) for the Los Angeles-South Coast Air Basin (South...

78 FR 30770 - Approval and Promulgation of Air Quality Implementation Plans; Illinois; Air Quality Standards...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-23

... Promulgation of Air Quality Implementation Plans; Illinois; Air Quality Standards Revision AGENCY... Illinois state implementation plan (SIP) to reflect current National Ambient Air Quality Standards (NAAQS... Implementation Plan at 35 Illinois Administrative Code part 243, which updates National Ambient Air Quality...

Rapid measurement of field-saturated hydraulic conductivity for areal characterization

USGS Publications Warehouse

Nimmo, J.R.; Schmidt, K.M.; Perkins, K.S.; Stock, J.D.

2009-01-01

To provide an improved methodology for characterizing the field-saturated hydraulic conductivity (Kfs) over broad areas with extreme spatial variability and ordinary limitations of time and resources, we developed and tested a simplified apparatus and procedure, correcting mathematically for the major deficiencies of the simplified implementation. The methodology includes use of a portable, falling-head, small-diameter (???20 cm) single-ring infiltrometer and an analytical formula for Kfs that compensates both for nonconstant falling head and for the subsurface radial spreading that unavoidably occurs with small ring size. We applied this method to alluvial fan deposits varying in degree of pedogenic maturity in the arid Mojave National Preserve, California. The measurements are consistent with a more rigorous and time-consuming Kfs measurement method, produce the expected systematic trends in Kfs when compared among soils of contrasting degrees of pedogenic development, and relate in expected ways to results of widely accepted methods. ?? Soil Science Society of America. All rights reserved.

Regional geophysical expression of a carbonatite terrane in the eastern Mojave Desert, California

USGS Publications Warehouse

Ponce, David A.; Denton, Kevin M.; Miller, David M.

2013-01-01

A world-class, rare earth element carbonatite deposit is located near Mountain Pass, in the eastern Mojave Desert of California and is hosted by Proterozoic rocks that extend along the eastern margins of the Clark Mountain Range, Mescal Range, and Ivanpah Mountains in a north-northwest trending fault-bounded block. This Proterozoic block is generally composed of a complex of 1.7 - 1.6 Ga gneisses and schists that are intruded by ~1.4 Ga carbonatite and ultrapotassic mafic dikes. In the latter suite, common intrusive rock types include shonkinite, syenite, and alkali granites that are associated with carbonatite dikes. Regional geophysical data reveal that the carbonatite deposit itself occurs along the northeast edge of a prominent magnetic high with an amplitude of 200 nanoteslas, which appears to be related to the surrounding Proterozoic block. More than 340 gravity stations and 155 physical property samples were collected to augment existing geophysical data to determine the geophysical and geologic setting of the eastern Mojave Desert carbonatite terrane. Physical properties of representative rock types in the area show that 23 samples of carbonatite ore have an average saturated bulk density of 2,866 with a range of 2,440 to 3,192 kg/m3 and a magnetic susceptibility of 0.22 with a range of 0.03 to 0.61x 10-3 SI units, 17 samples of syenite have an average saturated bulk density of 2,670 with a range of 2,555 to 2,788 kg/m3 and a magnetic susceptibility of 3.50 with a range of 0.19 to 11.46 x 10-3 SI units, 19 samples of shonkinite dike have an average saturated bulk density of 2,800 with a range of 2,603 to 3,000 kg/m3 and a magnetic susceptibility of 0.71 with a range of 0.00 to 4.44 x 10-3 SI units, and 28 samples of Proterozoic gneiss have an average saturated bulk density of 2,734 with a range of 2,574 to 3,086 kg/m3 and a magnetic susceptibility of 1.23 with a range of 0.01 to 7.48 x 10-3 SI units. In general, carbonatites have distinctive gravity, magnetic, and radiometric signatures because these deposits are relatively dense, have primary magnetite, and are enriched in thorium or uranium. In this case, because the carbonatite rocks in this Proterozoic terrane are themselves essentially nonmagnetic, they are not the source of the magnetic high associated with the Clark Mountain and Mescal Ranges. Instead, we suggest that weakly to moderately magnetic syenite intrusions or other granitic or metamorphic rocks in the region are the source of the magnetic high. Gravity data indicate that basins within the eastern Mojave carbonatite terrane are complicated. For example, a gravity high in the northern part of Ivanapah Valley suggest that the basin is underlain by shallow basement rocks, whereas the southern part of Ivanpah Valley extends to a depth of about 2 km. Combined gravity, magnetic, and geologic studies improve the current geophysical framework and structural interpretation of the eastern Mojave Desert carbonatite terrane.

AFRC2016-0082-13

NASA Image and Video Library

2016-03-10

NASA photographer Jim Ross captured this shot while pilot Troy Asher flew inverted in an F-15D. The F-15B is seen here flying over the mirror farm, AKA the Abengoa Mojave Solar Project, east of Four Corners off of Highway 58 in Southern California.

Test of Lander Vision System for Mars 2020

NASA Image and Video Library

2016-10-04

A prototype of the Lander Vision System for NASA Mars 2020 mission was tested in this Dec. 9, 2014, flight of a Masten Space Systems Xombie vehicle at Mojave Air and Space Port in California. http://photojournal.jpl.nasa.gov/catalog/PIA20848

40 CFR 52.1392 - Federal Implementation Plan for the Billings/Laurel Area.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Federal Implementation Plan for the Billings/Laurel Area. 52.1392 Section 52.1392 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Montana § 52.1392 Federal Implementation Plan for...

40 CFR 52.1392 - Federal Implementation Plan for the Billings/Laurel Area.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Federal Implementation Plan for the Billings/Laurel Area. 52.1392 Section 52.1392 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Montana § 52.1392 Federal Implementation Plan for...

40 CFR 52.1392 - Federal Implementation Plan for the Billings/Laurel Area.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Federal Implementation Plan for the Billings/Laurel Area. 52.1392 Section 52.1392 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Montana § 52.1392 Federal Implementation Plan for...

40 CFR 52.1392 - Federal Implementation Plan for the Billings/Laurel Area.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Federal Implementation Plan for the Billings/Laurel Area. 52.1392 Section 52.1392 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Montana § 52.1392 Federal Implementation Plan for...

77 FR 16937 - Approval and Promulgation of Air Quality Implementation Plans; West Virginia; Regional Haze State...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-23

... Promulgation of Air Quality Implementation Plans; West Virginia; Regional Haze State Implementation Plan AGENCY... limited disapproval of West Virginia's Regional Haze State Implementation Plan (SIP) revision. EPA is... mandatory Class I areas through a regional haze program. EPA is also approving this revision as meeting the...

77 FR 65151 - Finding of Substantial Inadequacy of Implementation Plan; Call for California State...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-25

... the Federal Register on September 19, 2012. In that action, in response to a remand by the Ninth... Substantial Inadequacy of Implementation Plan; Call for California State Implementation Plan Revision; South... State Implementation Plan (SIP) for the Los Angeles-South Coast Air Basin (South Coast) is substantially...

40 CFR 93.118 - Criteria and procedures: Motor vehicle emissions budget.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PLANS Conformity to State or Federal Implementation Plans of Transportation Plans, Programs, and..., consultation among federal, State, and local agencies occurred; full implementation plan documentation was... response to comments that are required to be submitted with any implementation plan. EPA will document its...

40 CFR 93.118 - Criteria and procedures: Motor vehicle emissions budget.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PLANS Conformity to State or Federal Implementation Plans of Transportation Plans, Programs, and..., consultation among federal, State, and local agencies occurred; full implementation plan documentation was... response to comments that are required to be submitted with any implementation plan. EPA will document its...

A strategy for prioritizing threats and recovery actions for at-risk species.

PubMed

Darst, Catherine R; Murphy, Philip J; Strout, Nathan W; Campbell, Steven P; Field, Kimberleigh J; Allison, Linda; Averill-Murray, Roy C

2013-03-01

Ensuring the persistence of at-risk species depends on implementing conservation actions that ameliorate threats. We developed and implemented a method to quantify the relative importance of threats and to prioritize recovery actions based on their potential to affect risk to Mojave desert tortoises (Gopherus agassizii). We used assessments of threat importance and elasticities of demographic rates from population matrix models to estimate the relative contributions of threats to overall increase in risk to the population. We found that urbanization, human access, military operations, disease, and illegal use of off highway vehicles are the most serious threats to the desert tortoise range-wide. These results suggest that, overall, recovery actions that decrease habitat loss, predation, and crushing will be most effective for recovery; specifically, we found that habitat restoration, topic-specific environmental education, and land acquisition are most likely to result in the greatest decrease in risk to the desert tortoise across its range. In addition, we have developed an application that manages the conceptual model and all supporting information and calculates threat severity and potential effectiveness of recovery actions. Our analytical approach provides an objective process for quantifying threats, prioritizing recovery actions, and developing monitoring metrics for those actions for adaptive management of any at-risk species.

40 CFR 49.10046 - Contents of implementation plan.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Plan for the Cow Creek Band of Umpqua Indians of Oregon § 49.10046 Contents of implementation plan. The implementation plan for the Reservation of the Cow Creek Band of Umpqua Indians consists of the following rules...

Implementing a Capital Plan.

ERIC Educational Resources Information Center

Daigneau, William A.

2003-01-01

Addresses four questions regarding implementation of a long-term capital plan to manage a college's facilities portfolio: When should the projects be implemented? How should the capital improvements be implemented? What will it actually cost in terms of project costs as well as operating costs? Who will implement the plan? (EV)

The influence of stream channels on distributions of Larrea tridentata and Ambrosia dumosa in the Mojave Desert, CA, USA: Patterns, mechanisms and effects of stream redistribution

USGS Publications Warehouse

Schwinning, S.; Sandquist, D.R.; Miller, D.M.; Bedford, D.R.; Phillips, S.L.; Belnap, J.

2011-01-01

Drainage channels are among the most conspicuous surficial features of deserts, but little quantitative analysis of their influence on plant distributions is available. We analysed the effects of desert stream channels (‘washes’) on Larrea tridentata and Ambrosia dumosa density and cover on an alluvial piedmont in the Mojave Desert, based on a spatial analysis of transect data encompassing a total length of 2775 m surveyed in 5 cm increments. Significant deviations from average transect properties were identified by bootstrapping. Predictably, shrub cover and density were much reduced inside washes, and elevated above average levels adjacent to washes. Average Larrea and Ambrosia cover and density peaked 1·2–1·6 m and 0·5–1·0 m from wash edges, respectively. We compared wash effects in runon-depleted (−R) sections, where washes had been cut off from runon and were presumably inactive, with those in runon-supplemented (+R) sections downslope from railroad culverts to help identify mechanisms responsible for the facilitative effect of washes on adjacent shrubs. Shrub cover and density near washes peaked in both + R and − R sections, suggesting that improved water infiltration and storage alone can cause a facilitative effect on adjacent shrubs. However, washes of < 2 m width in + R sections had larger than average effects on peak cover, suggesting that plants also benefit from occasional resource supplementation. The data suggest that channel networks significantly contribute to structuring plant communities in the Mojave Desert and their disruption has notable effects on geomorphic and ecological processes far beyond the original disturbance sites. 

Diet composition of common ravens across the urban-wildland interface of the West Mojave Desert

USGS Publications Warehouse

Kristan, William B.; Boarman, William I.; Crayon, John J.

2004-01-01

Common ravens (Corvus corax) are human-subsidized scavengers and predators in the Mojave Desert. They have increased dramatically in number and have been implicated as contributors to the decline in desert tortoise (Gopherus agassizii) populations. Known patterns of increased fledging success near human developments suggested that food was the most likely resource subsidy received by ravens. Because ravens are opportunistic foragers with a generalist diet, we predicted that the types of resource subsidy provided by different kinds of human developments should be reflected in measures of diet composition of breeding ravens. We estimated diet composition from contents of raven pellets collected at nests and related diet composition to distance of the nests from roads and point sources of resource subsidies, such as towns or landfills. Ravens that nested close to point subsidies far from major roads had the greatest incidence of trash in their diets. Ravens that nested close to roads but far from point subsidies had a low incidence of trash and a higher incidence of presumably road-killed mammals and reptiles. Ravens far from both roads and point subsidies had more plant material and arthropods, and ravens close to both roads and point subsidies had more birds and amphibians. Diet diversity was not related to distance from roads or developments. Fledging success was correlated with diet composition, such that birds with diets consistent with trash or road-kill subsidies fledged the greatest number of chicks. Our results suggest that ravens forage opportunistically on foods available near their nests, and different kinds of human developments contribute different foods. Improved management of landfills and highway fencing to reduce road-kills may help slow the growth of raven populations in the Mojave.

Geologic map of the Providence Mountains in parts of the Fountain Peak and adjacent 7.5' quadrangles, San Bernardino County, California

USGS Publications Warehouse

Stone, Paul; Miller, David M.; Stevens, Calvin H.; Rosario, Jose J.; Vazquez, Jorge A.; Wan, Elmira; Priest, Susan S.; Valin, Zenon C.

2017-03-22

IntroductionThe Providence Mountains are in the eastern Mojave Desert about 60 km southeast of Baker, San Bernardino County, California. This range, which is noted for its prominent cliffs of Paleozoic limestone, is part of a northeast-trending belt of mountainous terrain more than 100 km long that also includes the Granite Mountains, Mid Hills, and New York Mountains. Providence Mountains State Recreation Area encompasses part of the range, the remainder of which is within Mojave National Preserve, a large parcel of land administered by the National Park Service. Access to the Providence Mountains is by secondary roads leading south and north from Interstate Highways 15 and 40, respectively, which bound the main part of Mojave National Preserve.The geologic map presented here includes most of Providence Mountains State Recreation Area and land that surrounds it on the north, west, and south. This area covers most of the Fountain Peak 7.5′ quadrangle and small adjacent parts of the Hayden quadrangle to the north, the Columbia Mountain quadrangle to the northeast, and the Colton Well quadrangle to the east. The map area includes representative outcrops of most of the major geologic elements of the Providence Mountains, including gneissic Paleoproterozoic basement rocks, a thick overlying sequence of Neoproterozoic to Triassic sedimentary rocks, Jurassic rhyolite that intrudes and overlies the sedimentary rocks, Jurassic plutons and associated dikes, Miocene volcanic rocks, and a variety of Quaternary surficial deposits derived from local bedrock units. The purpose of the project was to map the area in detail, with primary emphasis on the pre-Quaternary units, to provide an improved stratigraphic, structural, and geochronologic framework for use in land management applications and scientific research.

Northward laramide thrusting in the quitovac region, northwestern sonora, mexico: Implications for the juxtaposition of paleoproterozoic basement blocks and the mojave-sonora megashear hypothesis

USGS Publications Warehouse

Iriondo, Alexander; Martínez-Torres, Luis M.; Kunk, Michael J.; Atkinson, William W.; Premo, Wayne R.; McIntosh, William C.

2005-01-01

Restoration of 12%–30% Basin and Range extension allows direct interpretation of ductile fabrics associated with a stack of Laramide thrust faults in the Quitovac region in northwestern Sonora. The inferred direction of displacement of these thrusts varies gradually from N63°W to N23°E and is interpreted to represent a clockwise rotation of the direction of Laramide thrusting through time. The thrust faults represent a piggy-back sequence of thrusting propagating north, toward the foreland. The average direction and sense of displacement of the thrusts is N18°W, and the cumulative 45 km of estimated northward-directed displacement corresponds to ∼86% of shortening.Based on geochronological constraints, onset of thrusting in Quitovac occurred sometime between 75 and 61 Ma, whereas cessation occurred at ca. 39 Ma. The presence of Paleocene-Eocene orogenic gold mineralization, spatially associated with thrusting, strengthens our idea that compressional tectonism associated with the Laramide orogeny is a very important and widespread dynamometamorphic event in the region.Similarities in age, kinematics, and structural stratigraphy indicate that the thrusting in the Quitovac region may be equivalent to the Laramide Quitobaquito Thrust in southwestern Arizona. In both areas, thrust faults juxtapose the Paleoproterozoic Caborca and “North America” basement blocks. This juxtaposition was previously proposed as exclusively related to movements along the hypothetical Upper Jurassic Mojave-Sonora megashear. The Laramide northward displacements and clockwise rotations recorded in the Caborca block rocks in Quitovac contradict the southward displacements (∼800 km) and counterclockwise rotations inherent in the left-lateral Upper Jurassic Mojave-Sonora megashear hypothesis. We conclude that if this megashear exists in northwestern Sonora, its trace should be to the southwest of the Quitovac region.

Can compliant fault zones be used to measure absolute stresses in the upper crust?

NASA Astrophysics Data System (ADS)

Hearn, E. H.; Fialko, Y.

2009-04-01

Geodetic and seismic observations reveal long-lived zones with reduced elastic moduli along active crustal faults. These fault zones localize strain from nearby earthquakes, consistent with the response of a compliant, elastic layer. Fault zone trapped wave studies documented a small reduction in P and S wave velocities along the Johnson Valley Fault caused by the 1999 Hector Mine earthquake. This reduction presumably perturbed a permanent compliant structure associated with the fault. The inferred changes in the fault zone compliance may produce a measurable deformation in response to background (tectonic) stresses. This deformation should have the same sense as the background stress, rather than the coseismic stress change. Here we investigate how the observed deformation of compliant zones in the Mojave Desert can be used to constrain the fault zone structure and stresses in the upper crust. We find that gravitational contraction of the coseismically softened zones should cause centimeters of coseismic subsidence of both the compliant zones and the surrounding region, unless the compliant fault zones are shallow and narrow, or essentially incompressible. We prefer the latter interpretation because profiles of line of sight displacements across compliant zones cannot be fit by a narrow, shallow compliant zone. Strain of the Camp Rock and Pinto Mountain fault zones during the Hector Mine and Landers earthquakes suggests that background deviatoric stresses are broadly consistent with Mohr-Coulomb theory in the Mojave upper crust (with μ ≥ 0.7). Large uncertainties in Mojave compliant zone properties and geometry preclude more precise estimates of crustal stresses in this region. With improved imaging of the geometry and elastic properties of compliant zones, and with precise measurements of their strain in response to future earthquakes, the modeling approach we describe here may eventually provide robust estimates of absolute crustal stress.

Mojave desert tortoise (Gopherus agassizii) thermal ecology and reproductive success along a rainfall cline.

PubMed

Sieg, Annette E; Gambone, Megan M; Wallace, Bryan P; Clusella-Trullas, Susana; Spotila, James R; Avery, Harold W

2015-05-01

Desert resource environments (e.g. microclimates, food) are tied to limited, highly localized rainfall regimes which generate microgeographic variation in the life histories of inhabitants. Typically, enhanced growth rates, reproduction and survivorship are observed in response to increased resource availability in a variety of desert plants and short-lived animals. We examined the thermal ecology and reproduction of US federally threatened Mojave desert tortoises (Gopherus agassizii), long-lived and large-bodied ectotherms, at opposite ends of a 250-m elevation-related rainfall cline within Ivanpah Valley in the eastern Mojave Desert, California, USA. Biophysical operative environments in both the upper-elevation, "Cima," and the lower-elevation, "Pumphouse," plots corresponded with daily and seasonal patterns of incident solar radiation. Cima received 22% more rainfall and contained greater perennial vegetative cover, which conferred 5°C-cooler daytime shaded temperatures. In a monitored average rainfall year, Cima tortoises had longer potential activity periods by up to several hours and greater ephemeral forage. Enhanced resource availability in Cima was associated with larger-bodied females producing larger eggs, while still producing the same number of eggs as Pumphouse females. However, reproductive success was lower in Cima because 90% of eggs were depredated versus 11% in Pumphouse, indicating that predatory interactions produced counter-gradient variation in reproductive success across the rainfall cline. Land-use impacts on deserts (e.g. solar energy generation) are increasing rapidly, and conservation strategies designed to protect and recover threatened desert inhabitants, such as desert tortoises, should incorporate these strong ecosystem-level responses to regional resource variation in assessments of habitat for prospective development and mitigation efforts. © 2015 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

Middle Miocene Displacement Along the Rand Detachment Fault, Rand Mountains

NASA Astrophysics Data System (ADS)

Shulaker, D. Z.; Grove, M. J.

2015-12-01

Laramide flat-slab subduction extinguished Sierra Nevada pluton emplacement in southern California by ca. 85 Ma as trench-derived sediments were underthrust and accreted beneath arc basement. These relationships are well illustrated in the Rand Mountains, situated just south of the Garlock fault in the northwestern Mojave Desert. Here, accreted rocks within the Rand Mountains are referred to as Rand Schist. The Rand Detachment fault juxtaposes Rand Schist beneath 87 Ma Sierran granitoids. New zircon (U-Th)/He age results from schist and basement juxtaposed across the Rand Detachment fault are 15 ± 3 Ma and 30 ± 5 Ma, respectively. When considered within the context of previously reported thermochronology from the Rand Mountains, our data shows that the Rand Detachment fault in the Rand Mountains is a middle Miocene fault that facilitated extension of the northwest Mojave Desert. This timing is in temporal and spatial agreement with regional extension throughout the Mojave triggered by northern migration of the slab window after collision of the Mendocino Triple Junction with the southern California margin. Further evidence of slab-window-related magmatism in the easternmost Rand Mountains is provided by the 19 Ma Yellow Aster pluton and 19 Ma rhyolite porphyry. It is possible that Miocene extension re-activated an older structure within the Rand Mountains. For example, a similar low-angle fault juxtaposing schist and basement present in the San Emigdio Mountains is believed to have accommodated large scale Late Cretaceous displacement, exhuming Rand Schist and overlying deepest Sierran basement to shallow crustal levels by 77 Ma [1]. However, 68-72 Ma phengite cooling ages and other thermochronology from the Rand Mountains indicates that any pre-Miocene extension in this area must postdate that in the San Emigdio Mountains. [1] Chapman et al., 2012. Geosphere, 8, 314-341.

VizieR Online Data Catalog: Optical spectroscopic atlas of MOJAVE AGNs (Torrealba+, 2012)

NASA Astrophysics Data System (ADS)

Torrealba, J.; Chavushyan, V.; Cruz-Gonzalez, I.; Arshakian, T. G.; Bertone, E.; Rosa-Gonzalez, D.

2014-09-01

The atlas includes spectral parameters for the emission lines Hβ, [OIII] 5007, MgII 2798 and/or CIV 1549 and corresponding data for the continuum, as well as the luminosities and equivalent widths of the FeII UV/optical. It also contains homogeneous photometric information in the B-band for 242 sources of the MOJAVE/2cm sample. These data were acquired at 2.1m mexican telescopes: Observatorio Astronomico Nacional in San Pedro Martir (OAN-SPM), B. C., Mexico and at Observatorio Astronomico Guillermo Haro, in Cananea, Sonora (OAGH), Mexico. It is supplemented with spectroscopic data found in the archives of the Sloan Digital Sky Survey (SDSS), the Hubble Space Telescope (HST), in the AGN sample of Marziani et al. (2003ApJS..145..199M, Cat. J/ApJS/145/199), and in Lawrence et al. 1996ApJS..107..541L. We present the continuum emission and/or line parameters for 41 sources in the Hβ region, 78 in the MgII region, and 35 in the CIV region. Also, there are 14 sources with information available for both Hβ and MgII regions, 12 with MgII and CIV, and 5 with Hβ, MgII and CIV. The spectroscopic information information for the statistically complete sample MOJAVE-1 (Lister & Homan, 2005AJ....130.1389L, Cat. J/AJ/130/1389) included in the Atlas is as follows: 28 sources in the Hβ region, 46 in the MgII region, and 23 in the CIV region. All the emission lines parameters are for the broad component of the line, except for [OIII] 5007. (7 data files).

A half-million-year record of paleoclimate from the Lake Manix Core, Mojave Desert, California

USGS Publications Warehouse

Reheis, Marith C.; Bright, Jordon; Lund, Steve P.; Miller, David M.; Skipp, Gary; Fleck, Robert J.

2012-01-01

Pluvial lakes in the southwestern U.S. responded sensitively to past climate through effects on rainfall, runoff, and evaporation. Although most studies agree that pluvial lakes in the southwestern U.S. reached their highest levels coeval with glacial stages, the specific timing of increased effective moisture and lake-level rise is debated, particularly for the southwesternmost lakes. We obtained a 45-m core of lacustrine sediment from Lake Manix, the former terminus of the Mojave River prior to about 25 ka, and supplemented data from the core with outcrop studies. These sediments provide a robust record of Mojave River discharge over the last half-million years. Lake Manix persisted from OIS 12 through early OIS 2, including during interstadial OIS 3 and interglacials OIS 5, 7, and 9. The ostracode faunal record displays a shift from an unexpectedly warm, summer-dominated lake hydrology during OIS 12 to predominantly colder, winter-dominated conditions afterwards. The ostracode-based stable isotope record displays a large degree of intra-sample variability and does not mimic other well-known isotopic records of climate change. Evaporation likely buffered the Manix δ18O record from most of the expected isotopic differences between interglacial and glacial-interval discharge. Isotopically depleted and stable lakes occurred only four to six times, most notably during OIS 7 and OIS 9. Internal drainage-basin changes also affected the isotopic record. Persistence of lakes in the Manix basin during interglacials requires atmospheric or oceanic circulation controls on the mean position of the Pacific storm track other than large ice sheets. We propose that the relative strength and sign of the Northern Annular Mode (NAM) and its influence on atmospheric river-derived precipitation is a potential explanation.

Making molehills out of mountains: landscape genetics of the Mojave desert tortoise

USGS Publications Warehouse

Hagerty, Bridgette E.; Nussear, Kenneth E.; Esque, Todd C.; Tracy, C. Richard

2010-01-01

Heterogeneity in habitat often influences how organisms traverse the landscape matrix that connects populations. Understanding landscape connectivity is important to determine the ecological processes that influence those movements, which lead to evolutionary change due to gene flow. Here, we used landscape genetics and statistical models to evaluate hypotheses that could explain isolation among locations of the threatened Mojave desert tortoise (Gopherus agassizii). Within a causal modeling framework, we investigated three factors that can influence landscape connectivity: geographic distance, barriers to dispersal, and landscape friction. A statistical model of habitat suitability for the Mojave desert tortoise, based on topography, vegetation, and climate variables, was used as a proxy for landscape friction and barriers to dispersal. We quantified landscape friction with least-cost distances and with resistance distances among sampling locations. A set of diagnostic partial Mantel tests statistically separated the hypotheses of potential causes of genetic isolation. The best-supported model varied depending upon how landscape friction was quantified. Patterns of genetic structure were related to a combination of geographic distance and barriers as defined by least-cost distances, suggesting that mountain ranges and extremely low-elevation valleys influence connectivity at the regional scale beyond the tortoises' ability to disperse. However, geographic distance was the only influence detected using resistance distances, which we attributed to fundamental differences between the two ways of quantifying friction. Landscape friction, as we measured it, did not influence the observed patterns of genetic distances using either quantification. Barriers and distance may be more valuable predictors of observed population structure for species like the desert tortoise, which has high dispersal capability and a long generation time.

Water Developments and Canids in Two North American Deserts: A Test of the Indirect Effect of Water Hypothesis

PubMed Central

Hall, Lucas K.; Larsen, Randy T.; Knight, Robert N.; Bunnell, Kevin D.; McMillan, Brock R.

2013-01-01

Anthropogenic modifications to landscapes intended to benefit wildlife may negatively influence wildlife communities. Anthropogenic provisioning of free water (water developments) to enhance abundance and distribution of wildlife is a common management practice in arid regions where water is limiting. Despite the long-term and widespread use of water developments, little is known about how they influence native species. Water developments may negatively influence arid-adapted species (e.g., kit fox, Vulpes macrotis) by enabling water-dependent competitors (e.g., coyote, Canis latrans) to expand distribution in arid landscapes (i.e., indirect effect of water hypothesis). We tested the two predictions of the indirect effect of water hypothesis (i.e., coyotes will visit areas with free water more frequently and kit foxes will spatially and temporally avoid coyotes) and evaluated relative use of free water by canids in the Great Basin and Mojave Deserts from 2010 to 2012. We established scent stations in areas with (wet) and without (dry) free water and monitored visitation by canids to these sites and visitation to water sources using infrared-triggered cameras. There was no difference in the proportions of visits to scent stations in wet or dry areas by coyotes or kit foxes at either study area. We did not detect spatial (no negative correlation between visits to scent stations) or temporal (no difference between times when stations were visited) segregation between coyotes and kit foxes. Visitation to water sources was not different for coyotes between study areas, but kit foxes visited water sources more in Mojave than Great Basin. Our results did not support the indirect effect of water hypothesis in the Great Basin or Mojave Deserts for these two canids. PMID:23844097

Wind erodibility of soils at Fort Irwin, California (Mojave Desert), USA, before and after trampling disturbance: Implications for land management

USGS Publications Warehouse

Belnap, J.; Phillips, S.L.; Herrick, J.E.; Johansen, J.R.

2007-01-01

Recently disturbed and 'control' (i.e. less recently disturbed) soils in the Mojave Desert were compared for their vulnerability to wind erosion, using a wind tunnel, before and after being experimentally trampled. Before trampling, control sites had greater cyanobacterial biomass, soil surface stability, threshold friction velocities (TFV, i.e. the wind speed required to move soil particles), and sediment yield than sites that had been more recently disturbed by military manoeuvres. After trampling, all sites showed a large drop in TFVs and a concomitant increase in sediment yield. Simple correlation analyses showed that the decline in TFVs and the rise in sediment yield were significantly related to cyanobacterial biomass (as indicated by soil chlorophyll a). However, chlorophyll a amounts were very low compared to chlorophyll a amounts found at cooler desert sites, where chlorophyll a is often the most important factor in determining TFV and sediment yield. Multiple regression analyses showed that other factors at Fort Irwin were more important than cyanobacterial biomass in determining the overall site susceptibility to wind erosion. These factors included soil texture (especially the fine, medium and coarse sand fractions), rock cover, and the inherent stability of the soil (as indicated by subsurface soil stability tests). Thus, our results indicate that there is a threshold of biomass below which cyanobacterial crusts are not the dominant factor in soil vulnerability to wind erosion. Most undisturbed soil surfaces in the Mojave Desert region produce very little sediment, but even moderate disturbance increases soil loss from these sites. Because current weathering rates and dust inputs are very low, soil formation rates are low as well. Therefore, soil loss in this region is likely to have long-term effects.

Soil water availability and microsite mediate fungal and bacterial phospholipid fatty acid biomarker abundances in Mojave Desert soils exposed to elevated atmospheric CO2

NASA Astrophysics Data System (ADS)

Jin, V. L.; Schaeffer, S. M.; Ziegler, S. E.; Evans, R. D.

2011-06-01

Changes in the rates of nitrogen (N) cycling, microbial carbon (C) substrate use, and extracellular enzyme activities in a Mojave Desert ecosystem exposed to elevated atmospheric CO2 suggest shifts in the size and/or functional characteristics of microbial assemblages in two dominant soil microsites: plant interspaces and under the dominant shrub Larrea tridentata. We used ester-linked phospholipid fatty acid (PLFA) biomarkers as a proxy for microbial biomass to quantify spatial and temporal differences in soil microbial communities from February 2003 to May 2005. Further, we used the 13C signature of the fossil CO2 source for elevated CO2 plots to trace recent plant C inputs into soil organic matter (SOM) and broad microbial groups using δ13C (‰). Differences between individual δ13CPLFA and δ13CSOM for fungal biomarkers indicated active metabolism of newer C in elevated CO2 soils. Total PLFA-C was greater in shrub microsites compared to plant interspaces, and CO2 treatment differences within microsites increased under higher soil water availability. Total, fungal, and bacterial PLFA-C increased with decreasing soil volumetric water content (VWC) in both microsites, suggesting general adaptations to xeric desert conditions. Increases in fungal-to-bacterial PLFA-C ratio with decreasing VWC reflected functional group-specific responses to changing soil water availability. While temporal and spatial extremes in resource availability in desert ecosystems contribute to the difficulty in identifying common trends or mechanisms driving microbial responses in less extreme environments, we found that soil water availability and soil microsite interacted with elevated CO2 to shift fungal and bacterial biomarker abundances in Mojave Desert soils.

40 CFR 52.1973 - Approval of plans.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Oregon § 52.1973 Approval of plans. (a) Carbon monoxide. (1) EPA approves as a revision to the Oregon State Implementation Plan, the Second... December 27, 2004. (2) EPA approves as a revision to the Oregon State Implementation Plan, the Salem carbon...

40 CFR 52.1973 - Approval of plans.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Oregon § 52.1973 Approval of plans. (a) Carbon monoxide. (1) EPA approves as a revision to the Oregon State Implementation Plan, the Second... December 27, 2004. (2) EPA approves as a revision to the Oregon State Implementation Plan, the Salem carbon...

40 CFR 52.1973 - Approval of plans.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Oregon § 52.1973 Approval of plans. (a) Carbon monoxide. (1) EPA approves as a revision to the Oregon State Implementation Plan, the Second... December 27, 2004. (2) EPA approves as a revision to the Oregon State Implementation Plan, the Salem carbon...

40 CFR 52.1973 - Approval of plans.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Oregon § 52.1973 Approval of plans. (a) Carbon monoxide. (1) EPA approves as a revision to the Oregon State Implementation Plan, the Second... December 27, 2004. (2) EPA approves as a revision to the Oregon State Implementation Plan, the Salem carbon...

49 CFR 633.27 - Implementation of a project management plan.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Implementation of a project management plan. 633... TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROJECT MANAGEMENT OVERSIGHT Project Management Plans § 633.27 Implementation of a project management plan. (a) Upon approval of a project management plan by...

49 CFR 633.27 - Implementation of a project management plan.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Implementation of a project management plan. 633... TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROJECT MANAGEMENT OVERSIGHT Project Management Plans § 633.27 Implementation of a project management plan. (a) Upon approval of a project management plan by...

49 CFR 633.27 - Implementation of a project management plan.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Implementation of a project management plan. 633... TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROJECT MANAGEMENT OVERSIGHT Project Management Plans § 633.27 Implementation of a project management plan. (a) Upon approval of a project management plan by...

49 CFR 633.27 - Implementation of a project management plan.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Implementation of a project management plan. 633... TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROJECT MANAGEMENT OVERSIGHT Project Management Plans § 633.27 Implementation of a project management plan. (a) Upon approval of a project management plan by...

49 CFR 633.27 - Implementation of a project management plan.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Implementation of a project management plan. 633... TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROJECT MANAGEMENT OVERSIGHT Project Management Plans § 633.27 Implementation of a project management plan. (a) Upon approval of a project management plan by...

76 FR 9706 - Finding of Substantial Inadequacy of Implementation Plan; Call for Iowa State Implementation Plan...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-22

... advance and available for prompt implementation once triggered. Section 110(k)(5) of the CAA provides that... Environmental protection, Air pollution control, Iowa, Particulate matter, State Implementation Plan. Dated...

Developing and Implementing a Citywide Asthma Action Plan: A Community Collaborative Partnership.

PubMed

Staudt, Amanda Marie; Alamgir, Hasanat; Long, Debra Lynn; Inscore, Stephen Curtis; Wood, Pamela Runge

2015-12-01

Asthma affects 1 in 10 children in the United States, with higher prevalence among children living in poverty. Organizations in San Antonio, Texas, partnered to design and implement a uniform, citywide asthma action plan to improve asthma management capacity in schools. The asthma action plan template was modified from that of the Global Initiative for Asthma. School personnel were trained in symptom recognition, actions to take, and use of equipment before the asthma action plan implementation. The annual Asthma Action Plan Summit was organized as a forum for school nurses, healthcare providers, and members of the community to exchange ideas and strategies on implementation, as well as to revise the plan. The asthma action plan was implemented in all 16 local school districts. Feedback received from school nurses suggests that the citywide asthma action plan resulted in improved asthma management and student health at schools. The evidence in this study suggests that community organizations can successfully collaborate to implement a citywide health initiative similar to the asthma action plan.

Participatory System Dynamics Modeling: Increasing Stakeholder Engagement and Precision to Improve Implementation Planning in Systems.

PubMed

Zimmerman, Lindsey; Lounsbury, David W; Rosen, Craig S; Kimerling, Rachel; Trafton, Jodie A; Lindley, Steven E

2016-11-01

Implementation planning typically incorporates stakeholder input. Quality improvement efforts provide data-based feedback regarding progress. Participatory system dynamics modeling (PSD) triangulates stakeholder expertise, data and simulation of implementation plans prior to attempting change. Frontline staff in one VA outpatient mental health system used PSD to examine policy and procedural "mechanisms" they believe underlie local capacity to implement evidence-based psychotherapies (EBPs) for PTSD and depression. We piloted the PSD process, simulating implementation plans to improve EBP reach. Findings indicate PSD is a feasible, useful strategy for building stakeholder consensus, and may save time and effort as compared to trial-and-error EBP implementation planning.

75 FR 71121 - Combined Notice Of Filings No 2

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-22

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Combined Notice Of Filings No 2 November 10, 2010. Take notice that the Commission has received the following Natural Gas Pipeline Rate and Refund Report filings: Docket Numbers: RP10-1082-001. Applicants: Mojave Pipeline Company, LLC...

A comparison of soil climate and biological activity along an elevation gradient in the eastern Mojave Desert

USGS Publications Warehouse

Amundson, R.G.; Chadwick, O.A.; Sowers, J.M.

1989-01-01

Soil temperature, moisture, and CO2 were monitored at four sites along an elevation transect in the eastern Mojave Desert from January to October, 1987. Climate appeared to be the major factor controlling CO2 partial pressures, primarily through its influence of rates of biological reactions, vegetation densities, and organic matter production. With increasing elevation, and increasing actual evapotranspiration, the organic C, plant density, and the CO2 content of the soils increased. Between January and May, soil CO2 concentrations at a given site were closely related to variations in soil temperature. In July and October, temperatures had little effect on CO2, presumably due to low soil moisture levels. Up to 75% of litter placed in the field in March was lost by October whereas, for the 3 lower elevations, less than 10% of the litter placed in the field in April was lost through decomposition processes. ?? 1989 Springer-Verlag.

Geochronology of the proterozoic basement of southwesternmost North America, and the origin and evolution of the Mojave crustal province

USGS Publications Warehouse

Barth, Andrew P.; Wooden, Joseph L.; Coleman, Drew S.; Fanning, C. Mark

2000-01-01

The Proterozoic Baldwin gneiss in the central Transverse Ranges of southern California, a part of the Mojave crustal province, is composed of quartzofeldspathic gneiss and schist, augen and granitic gneiss, trondhjemite gneiss, and minor quartzite, amphibolite, metagabbro, and metapyroxenite. Sensitive high resolution ion microprobe (SHRIMP) data indicate that augen and granitic gneisses comprise a magmatic arc intrusive suite emplaced between 1783 ± 12 and 1675 ± 19 Ma, adjacent to or through thinned Archean crust. High U/Th rims on zircons in most samples suggest an early metamorphic event at ∼1741 Ma, but peak amphibolite facies metamorphism and penetrative, west vergent deformation occurred after 1675 Ma. The Baldwin gneiss is part of a regional allochthon emplaced by west vergent deformation over a Proterozoic shelf-slope sequence (Joshua Tree terrane). We hypothesize that emplacement of this regional allochthon occurred during a late Early or Middle Proterozoic arc-continent collision along the western margin of Laurentia.

Effects of livestock watering sites on alien and native plants in the Mojave Desert, USA

USGS Publications Warehouse

Brooks, M.L.; Matchett, J.R.; Berry, K.H.

2006-01-01

Increased livestock densities near artificial watering sites create disturbance gradients called piospheres. We studied responses of alien and native annual plants and native perennial plants within 9 piospheres in the Mojave Desert of North America. Absolute and proportional cover of alien annual plants increased with proximity to watering sites, whereas cover and species richness of native annual plants decreased. Not all alien species responded the same, as the alien forb Erodium cicutarium and the alien grass Schismus spp. increased with proximity to watering sites, and the alien annual grass Bromus madritensis ssp. rubens decreased. Perennial plant cover and species richness also declined with proximity to watering sites, as did the structural diversity of perennial plant cover classes. Significant effects were focused within 200 m of the watering sites, suggesting that control efforts for alien annual plants and restoration efforts for native plants should optimally be focused within this central part of the piosphere gradient.

Comparison of Kalman filter estimates of zenith atmospheric path delays using the global positioning system and very long baseline interferometry

NASA Technical Reports Server (NTRS)

Tralli, David M.; Lichten, Stephen M.; Herring, Thomas A.

1992-01-01

Kalman filter estimates of zenith nondispersive atmospheric path delays at Westford, Massachusetts, Fort Davis, Texas, and Mojave, California, were obtained from independent analyses of data collected during January and February 1988 using the GPS and VLBI. The apparent accuracy of the path delays is inferred by examining the estimates and covariances from both sets of data. The ability of the geodetic data to resolve zenith path delay fluctuations is determined by comparing further the GPS Kalman filter estimates with corresponding wet path delays derived from water vapor radiometric data available at Mojave over two 8-hour data spans within the comparison period. GPS and VLBI zenith path delay estimates agree well within one standard deviation formal uncertainties (from 10-20 mm for GPS and 3-15 mm for VLBI) in four out of the five possible comparisons, with maximum differences of 5 and 21 mm over 8- to 12-hour data spans.

Data measured on water collected from eastern Mojave Desert, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rose, Tim P.

In March of 2000 field collection of water from the Eastern Mojave Desert resulted in the measurement of stable isotope, radiocarbon, tritium, and limited dissolved noble gases. This work was follow-on to previous studies on similar systems in southern Nevada associated with the Nevada Test Site (Davisson et al., 1999; Rose and Davisson, 2003). The data for groundwater from wells and springs was never formally published and is therefore tabulated in Table 1 in order to be recorded in public record. In addition 4 years of remote precipitation data was collected for stable isotopes and is included in Table 2.more » These studies, along with many parallel and subsequent ones using isotopes and elemental concentrations, are all related to the general research area of tracing sources and quantifying transport times of natural and man-made materials in the environment. This type of research has direct relevance in characterizing environmental contamination, understanding resource development and protection, designing early detection in WMD related terrorism, and application in forensics analysis.« less

Kinematics and mechanics of tectonic block rotations

NASA Technical Reports Server (NTRS)

Nur, Amos; Scotti, Oona; Ron, Hagai

1989-01-01

Paleomagnetic, structural geology, and rock mechanics data are combined to explore the validity of the block rotation concept and its significance. The analysis is based on data from (1) Northern Israel, where fault slip and spacing are used to predict block rotation; (2) the Mojave Desert, with well-documented strike-slip fault sets, organized in at least three major domains; (3) the Lake Mead, Nevada, fault system with well-defined sets of strike-slip faults, which, in contrast to the Mojave region, are surrounded with domains of normal faults; and (4) the San Gabriel Mountains domain with a multiple set of strike-slip faults. It is found that block rotations can have a profound influence on the interpretation of geodetic measurements and the inversion of geodetic data, especially the type collected in GPS surveys. Furthermore, block rotations and domain boundaries may be involved in creating the heterogeneities along active fault systems which are responsible for the initiation and termination of earthquake rupture.

75 FR 54805 - Approval and Promulgation of Air Quality Implementation Plans; Minnesota; Carbon Monoxide (CO...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-09

... Promulgation of Air Quality Implementation Plans; Minnesota; Carbon Monoxide (CO) Limited Maintenance Plan for... June 16, 2010, to revise the Minnesota State Implementation Plan (SIP) for carbon monoxide (CO) under the Clean Air Act (CAA). The State has submitted a limited maintenance plan for CO showing continued...

40 CFR 49.9861 - Identification of plan.

Code of Federal Regulations, 2010 CFR

2010-07-01

... TRIBAL CLEAN AIR ACT AUTHORITY Implementation Plans for Tribes-Region X Implementation Plan for the Burns Paiute Tribe of the Burns Paiute Indian Colony of Oregon § 49.9861 Identification of plan. This section and §§ 49.9862 through 49.9890 contain the implementation plan for the Burns Paiute Tribe of the Burns...

75 FR 63139 - Approval and Promulgation of Implementation Plans-Maricopa County (Phoenix) PM-10 Nonattainment...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-14

... Promulgation of Implementation Plans--Maricopa County (Phoenix) PM-10 Nonattainment Area; Serious Area Plan for... implementation plan (SIP) revisions submitted by the State of Arizona to meet, among other requirements, section... (Maricopa area). Specifically, EPA proposed to disapprove provisions of the 189(d) plan because they do not...

Design requirements for SRB production control system. Volume 4: Implementation

NASA Technical Reports Server (NTRS)

1981-01-01

The implementation plan which is presented was developed to provide the means for the successful implementation of the automated production control system. There are three factors which the implementation plan encompasses: detailed planning; phased implementation; and user involvement. The plan is detailed to the task level in terms of necessary activities as the system is developed, refined, installed, and tested. These tasks are scheduled, on a preliminary basis, over a two-and-one-half-year time frame.

40 CFR 256.42 - Recommendations for assuring facility development.

Code of Federal Regulations, 2014 CFR

2014-07-01

... WASTES GUIDELINES FOR DEVELOPMENT AND IMPLEMENTATION OF STATE SOLID WASTE MANAGEMENT PLANS Facility Planning and Implementation § 256.42 Recommendations for assuring facility development. (a) The State plan... facilities, and (4) Development of schedules of implementation. (d) The State plan should encourage private...

40 CFR 256.42 - Recommendations for assuring facility development.

Code of Federal Regulations, 2012 CFR

2012-07-01

... WASTES GUIDELINES FOR DEVELOPMENT AND IMPLEMENTATION OF STATE SOLID WASTE MANAGEMENT PLANS Facility Planning and Implementation § 256.42 Recommendations for assuring facility development. (a) The State plan... facilities, and (4) Development of schedules of implementation. (d) The State plan should encourage private...

40 CFR 256.42 - Recommendations for assuring facility development.

Code of Federal Regulations, 2013 CFR

2013-07-01

... WASTES GUIDELINES FOR DEVELOPMENT AND IMPLEMENTATION OF STATE SOLID WASTE MANAGEMENT PLANS Facility Planning and Implementation § 256.42 Recommendations for assuring facility development. (a) The State plan... facilities, and (4) Development of schedules of implementation. (d) The State plan should encourage private...

75 FR 3680 - Revisions to the California State Implementation Plan

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-22

... the California State Implementation Plan AGENCY: Environmental Protection Agency (EPA). ACTION... Pollution Control District (SJVAPCD) portion of the California State Implementation Plan (SIP). These... are taking comments on this proposal and plan to follow with a final action. DATES: Any comments must...

49 CFR 130.33 - Response plan implementation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 2 2014-10-01 2014-10-01 false Response plan implementation. 130.33 Section 130... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION OIL TRANSPORTATION OIL SPILL PREVENTION AND RESPONSE PLANS § 130.33 Response plan implementation. If, during transportation of oil subject to this part, a...

49 CFR 130.33 - Response plan implementation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Response plan implementation. 130.33 Section 130... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION OIL TRANSPORTATION OIL SPILL PREVENTION AND RESPONSE PLANS § 130.33 Response plan implementation. If, during transportation of oil subject to this part, a...

49 CFR 130.33 - Response plan implementation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Response plan implementation. 130.33 Section 130... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION OIL TRANSPORTATION OIL SPILL PREVENTION AND RESPONSE PLANS § 130.33 Response plan implementation. If, during transportation of oil subject to this part, a...

49 CFR 130.33 - Response plan implementation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 2 2012-10-01 2012-10-01 false Response plan implementation. 130.33 Section 130... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION OIL TRANSPORTATION OIL SPILL PREVENTION AND RESPONSE PLANS § 130.33 Response plan implementation. If, during transportation of oil subject to this part, a...

49 CFR 130.33 - Response plan implementation.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 2 2013-10-01 2013-10-01 false Response plan implementation. 130.33 Section 130... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION OIL TRANSPORTATION OIL SPILL PREVENTION AND RESPONSE PLANS § 130.33 Response plan implementation. If, during transportation of oil subject to this part, a...

76 FR 28195 - Approval and Promulgation of Air Quality Implementation Plans; New Mexico; Sunland Park 1-Hour...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-16

... Promulgation of Air Quality Implementation Plans; New Mexico; Sunland Park 1-Hour Ozone Maintenance Plan AGENCY... the New Mexico State Implementation Plan (SIP). The revision consists of a maintenance plan for Sunland Park, New Mexico developed to ensure continued attainment of the 8-hour ozone National Ambient Air...

Design and Implementation of the PMS Module for ’Argos’

DTIC Science & Technology

1989-12-01

designing , and implementing a fully workable Planned Maintenance System (PMS). This implementation demonstrates both the capabilities and benefits such a...analyzing, designing , and implementing a fully workable Planned Maintenance System (PMS). This implementation demonstrates both the capabilities and... design and implementation. PMS is the system developed by the navy to provide each ship, department, and supervisor with the tools needed to plan

Invasion of shrublands by exotic grasses: Ecohydrological consequences in cold vs. warm deserts

USDA-ARS?s Scientific Manuscript database

Across the globe, native savannas and woodlands are undergoing conversion to exotic grasslands. Here we summarize the current state of knowledge concerning the ecohydrological consequences of this conversion for the cold deserts (Great Basin, Colorado Plateau) and the warm deserts (Mojave, Sonoran, ...

The Rural School Principalship: Unique Challenges, Opportunities.

ERIC Educational Resources Information Center

Hill, Jonathan

1993-01-01

Presents findings based on author's research and experience as principal in California's Mojave Desert. Five basic characteristics distinguish the rural principalship: lack of an assistant principal or other support staff; assumption of other duties, including central office tasks, teaching, or management of another site; less severe student…

Assessing Multi-scale Reptile and Amphibian Biodiversity: Mojave Ecoregion Case Study

EPA Science Inventory

The ability to assess, report, map, and forecast the life support functions of ecosystems is absolutely critical to our capacity to make informed decisions to maintain the sustainable nature of our environment now and into the future. Because of the variability among living orga...

Implementation of Discharge Plans for Chronically Ill Elders Discharged Home.

ERIC Educational Resources Information Center

Proctor, Enola K.; And Others

1996-01-01

Addresses the extent to which discharge plans for elderly patients with congestive heart failure were implemented as planned, tested the consequences of implementation problems, and identified factors associated with implementation problems. Implications for hospital discharge planners and home health care are discussed. (KW)

40 CFR 49.10042 - Approval status.

Code of Federal Regulations, 2010 CFR

2010-07-01

... TRIBAL CLEAN AIR ACT AUTHORITY Implementation Plans for Tribes-Region X Implementation Plan for the Cow... Tribal rules or measures in the implementation plan for the Reservation of the Cow Creek Band of Umpqua...

Ames Research Center FY 2000 Implementation Plan: Leading Technology into the New Millennium

NASA Technical Reports Server (NTRS)

2000-01-01

This document presents the implementation plan for Ames Research Center (ARC) within the overall framework of the NASA Strategic Plan. It describes how ARC intends to implement its Center of Excellence responsibilities, Agency assigned missions, Agency and Enterprise lead programs, and other roles in support of NASA's vision and mission. All Federal agencies are required by the 1993 Government Performance and Results Act to implement a long-term strategic planning process that includes measurable outcomes and strict accountability. At NASA, this planning process is shaped by the Space Act of 1958, annual appropriations, and other external mandates, as well as by customer requirements. The resulting Strategic Plan sets the overall architecture for what we do, identifies who our customers are, and directs where we are going and why. The Strategic Plan is the basis upon which decisions regarding program implementation and resource deployment are made. Whereas the strategic planning process examines the long-term direction of the organization and identifies a specific set of goals, the implementation planning process examines the detailed performance of the organization and allocates resources toward meeting these goals. It is the purpose of this implementation document to provide the connection between the NASA Strategic Plan and the specific programs and support functions that ARC employees perform. This connection flows from the NASA Strategic Plan, through the various Strategic Enterprise plans to the ARC Center of Excellence, primary missions, Lead Center programs, program support responsibilities, and ultimately, to the role of the individual ARC employee.

77 FR 60661 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; South Bend-Elkhart...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-04

... Promulgation of Air Quality Implementation Plans; Indiana; South Bend-Elkhart, Indiana Ozone Maintenance Plan..., Indiana 1997 8-hour ozone maintenance air quality State Implementation Plan (SIP) by replacing the... Vehicle Emissions Simulator (MOVES) 2010a emissions model. Indiana submitted this request to EPA for...

77 FR 59356 - Approval and Promulgation of Implementation Plans; North Carolina: Approval of Rocky Mount...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-27

... Promulgation of Implementation Plans; North Carolina: Approval of Rocky Mount Supplemental Motor Vehicle... is proposing to approve a revision to the North Carolina State Implementation Plan (SIP), submitted... supplements the original redesignation request and maintenance plan for Rocky Mount 1997 8-hour ozone area...

77 FR 30212 - Approval and Promulgation of Air Quality Implementation Plans; Vermont; Regional Haze

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-22

... Promulgation of Air Quality Implementation Plans; Vermont; Regional Haze AGENCY: Environmental Protection... Implementation Plan (SIP) that addresses regional haze for the first planning period from 2008 through 2018. The... numerous sources located over a wide geographic area (also referred to as the ``regional haze program...

77 FR 47530 - Approval and Promulgation of State Implementation Plans; Hawaii; Infrastructure Requirements for...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-09

... Promulgation of State Implementation Plans; Hawaii; Infrastructure Requirements for the 1997 8-Hour Ozone and... State Implementation Plan (SIP) revision submitted by the state of Hawaii pursuant to the requirements... FURTHER INFORMATION CONTACT: Dawn Richmond, Air Planning Office (AIR-2), U.S. Environmental Protection...

75 FR 4582 - Mojave-Southern Great Basin Resource Advisory Council Meetings, Nevada

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-28

... District Office Manager. [FR Doc. 2010-1729 Filed 1-27-10; 8:45 am] BILLING CODE 4310-HC-P ... include, but are not limited to: February 18, BLM Southern Nevada District Office, 4701 N. Torrey Pines Dr... Southern Nevada District Office, 4701 N. Torrey [[Page 4583

Prospects for Classical Biological Control of Saharan Mustard (Brassica tournefortii)

USDA-ARS?s Scientific Manuscript database

Saharan mustard (Brassica tournefortii) is a winter annual plant that is native to the Mediterranean Basin and is becoming highly invasive in the Sonoran and Mojave Deserts and adjacent areas and has spread great distances along highways from its original infestation. It is becoming a serious probl...

BIOGENIC VOLATILE ORGANIC COMPOUND EMISSIONS FROM DESERT VEGETATION OF THE SOUTHWESTERN U.S.

EPA Science Inventory

Thirteen common plant species in the Mojave and Sonoran Desert regions of the western United States were tested for emissions of biogenic non-methane volatile organic compounds (BVOCs). Only two of the species examined emitted isoprene at rates of 10 µgCg⁻¹ ...

75 FR 3487 - Notice of Public Meeting: Recreation Subcommittee of the Sierra Front-Northwestern Great Basin...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-21

... Area (NCA) Scenic Loop managed by the Bureau of Land Management. Date and Time: The Recreation... DEPARTMENT OF THE INTERIOR Bureau of Land Management DEPARTMENT OF AGRICULTURE Forest Service..., and Mojave- Southern Great Basin Resource Advisory Councils, Nevada AGENCY: Bureau of Land Management...

Goldstone radio spectrum protection. [deep space network

NASA Technical Reports Server (NTRS)

Gaudian, B. A.; Cushman, R. B.

1980-01-01

Potential electromagnetic interference to the Goldstone tracking receivers due to neighboring military installations is discussed. Coordination of the military and NASA Goldstone activities in the Mojave Desert area is seen to be an effective method to protect the Goldstone radio spectrum while maintaining compatible operations for the military and Goldstone.

Planning Targets for Phase II Watershed Implementation Plans

EPA Pesticide Factsheets

On August 1, 2011, EPA provided planning targets for nitrogen, phosphorus and sediment for the Phase II Watershed Implementation Plans (WIPs) of the Chesapeake Bay TMDL. This page provides the letters containing those planning targets.

Building robust conservation plans.

PubMed

Visconti, Piero; Joppa, Lucas

2015-04-01

Systematic conservation planning optimizes trade-offs between biodiversity conservation and human activities by accounting for socioeconomic costs while aiming to achieve prescribed conservation objectives. However, the most cost-efficient conservation plan can be very dissimilar to any other plan achieving the set of conservation objectives. This is problematic under conditions of implementation uncertainty (e.g., if all or part of the plan becomes unattainable). We determined through simulations of parallel implementation of conservation plans and habitat loss the conditions under which optimal plans have limited chances of implementation and where implementation attempts would fail to meet objectives. We then devised a new, flexible method for identifying conservation priorities and scheduling conservation actions. This method entails generating a number of alternative plans, calculating the similarity in site composition among all plans, and selecting the plan with the highest density of neighboring plans in similarity space. We compared our method with the classic method that maximizes cost efficiency with synthetic and real data sets. When implementation was uncertain--a common reality--our method provided higher likelihood of achieving conservation targets. We found that χ, a measure of the shortfall in objectives achieved by a conservation plan if the plan could not be implemented entirely, was the main factor determining the relative performance of a flexibility enhanced approach to conservation prioritization. Our findings should help planning authorities prioritize conservation efforts in the face of uncertainty about future condition and availability of sites. © 2014 Society for Conservation Biology.

76 FR 15 - Approval and Promulgation of Implementation Plans; Texas; Emissions Banking and Trading of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-03

... Promulgation of Implementation Plans; Texas; Emissions Banking and Trading of Allowances Program AGENCY... to the Texas State Implementation Plan (SIP) that create and amend the Emissions Banking and Trading... hard copy at the Air Planning Section (6PD-L), Environmental Protection Agency, 1445 Ross Avenue, Suite...

78 FR 33784 - Approval and Promulgation of Implementation Plans; Kentucky: Kentucky Portion of Cincinnati...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-05

... Promulgation of Implementation Plans; Kentucky: Kentucky Portion of Cincinnati-Hamilton, Supplement Motor.... SUMMARY: EPA is proposing to approve a revision to the Kentucky State Implementation Plan (SIP), submitted... maintenance plan for the Kentucky portion of the Cincinnati-Hamilton, OH-KY-IN, maintenance area for the 1997...

78 FR 34903 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; 1997 8-Hour Ozone...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-11

... Promulgation of Air Quality Implementation Plans; Ohio; 1997 8-Hour Ozone Maintenance Plan Revision; Motor... request by Ohio to revise the 1997 8-hour ozone maintenance air quality State Implementation Plan (SIP) to... area with budgets developed using EPA's Motor Vehicle Emissions Simulator (MOVES) emissions model. Ohio...

78 FR 16826 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Cleveland-Akron-Lorain and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-19

...-9790-1] Approval and Promulgation of Air Quality Implementation Plans; Ohio; Cleveland-Akron-Lorain and Columbus 1997 8-Hour Ozone Maintenance Plan Revisions to Approved Motor Vehicle Emissions Budgets AGENCY... quality State Implementation Plans (SIPs) under the Clean Air Act to replace the previously approved motor...

78 FR 28497 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Canton-Massillon 1997 8-Hour...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-15

... Promulgation of Air Quality Implementation Plans; Ohio; Canton-Massillon 1997 8-Hour Ozone Maintenance Plan... the Canton-Massillon, Ohio 1997 8-hour ozone maintenance air quality State Implementation Plan (SIP... using EPA's Motor Vehicle Emissions Simulator (MOVES) emissions model. Ohio submitted the SIP revision...

78 FR 28551 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Canton-Massillon 1997 8-Hour...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-15

... Promulgation of Air Quality Implementation Plans; Ohio; Canton-Massillon 1997 8-Hour Ozone Maintenance Plan..., Ohio, 1997 8-hour ozone maintenance air quality State Implementation Plan (SIP) under the Clean Air Act... Motor Vehicle Emissions Simulator (MOVES) emissions model. Ohio submitted the SIP revision request to...

77 FR 30214 - Approval and Promulgation of Air Quality Implementation Plans; Rhode Island; Regional Haze

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-22

... Promulgation of Air Quality Implementation Plans; Rhode Island; Regional Haze AGENCY: Environmental Protection... Implementation Plan (SIP) that addresses regional haze for the first planning period from 2008 through 2018. The... geographic area (also referred to as the ``regional haze program''). DATES: Effective Date: This rule is...

76 FR 43149 - Approval and Promulgation of Air Quality Implementation Plans; State of California; Regional Haze...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-20

... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R09-OAR-2011-0131, FRL-9317-9] Approval and Promulgation of Air Quality Implementation Plans; State of California; Regional Haze State Implementation Plan and Interstate Transport Plan; Interference With Visibility Requirement Correction In rule document...

76 FR 57013 - Approval and Promulgation of Air Quality Implementation Plans; West Virginia; Revised Motor...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-15

... Promulgation of Air Quality Implementation Plans; West Virginia; Revised Motor Vehicle Emission Budgets for the... Implementation Plan (SIP) revision submitted by the State of West Virginia for the purpose of amending the 8-hour ozone maintenance plan for the Charleston, Huntington, Parkersburg, Weirton, and Wheeling 8-hour ozone...

40 CFR 109.5 - Development and implementation criteria for State, local and regional oil removal contingency plans.

Code of Federal Regulations, 2012 CFR

2012-07-01

... OIL REMOVAL CONTINGENCY PLANS § 109.5 Development and implementation criteria for State, local and regional oil removal contingency plans. Criteria for the development and implementation of State, local and... 40 Protection of Environment 23 2012-07-01 2012-07-01 false Development and implementation...

77 FR 65125 - Approval and Promulgation of Implementation Plans; Georgia 110(a)(1) and (2) Infrastructure...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-25

... controls are enforced through the associated SIP rules or Federal Implementation Plans (FIPs). Any purchase... Promulgation of Implementation Plans; Georgia 110(a)(1) and (2) Infrastructure Requirements for the 1997 and... Agency (EPA). ACTION: Final rule. SUMMARY: EPA is taking final action to approve the State Implementation...

Implementing corporate wellness programs: a business approach to program planning.

PubMed

Helmer, D C; Dunn, L M; Eaton, K; Macedonio, C; Lubritz, L

1995-11-01

1. Support of key decision makers is critical to the successful implementation of a corporate wellness program. Therefore, the program implementation plan must be communicated in a format and language readily understood by business people. 2. A business approach to corporate wellness program planning provides a standardized way to communicate the implementation plan. 3. A business approach incorporates the program planning components in a format that ranges from general to specific. This approach allows for flexibility and responsiveness to changes in program planning. 4. Components of the business approach are the executive summary, purpose, background, ground rules, approach, requirements, scope of work, schedule, and financials.

40 CFR 49.10050 - Federally-promulgated regulations and Federal implementation plans.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-Region X Implementation Plan for the Cow Creek Band of Umpqua Indians of Oregon § 49.10050 Federally... part of the implementation plan for the Reservation of the Cow Creek Band of Umpqua Indians: (a...

Planning for strategic change? A participative planning approach for community hospitals.

PubMed

MacDonald, S K; Beange, J E; Blachford, P C

1992-01-01

Strategic planning is becoming to hospitals what business case analysis is to private corporations. In fact, this type of planning is becoming essential for the professional management of Ontario hospitals. The participative strategic planning process at Toronto East General Hospital (TEGH) is an example of how a professionally structured and implemented strategic planning process can be successfully developed and implemented in a community hospital. In this article, the environmental factors driving planning are reviewed and the critical success factors for the development and implementation of a strategic plan are examined in the context of TEGH's experience.

78 FR 34965 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Lima 1997 8-Hour Ozone...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-11

... Promulgation of Air Quality Implementation Plans; Ohio; Lima 1997 8-Hour Ozone Maintenance Plan Revision; Motor... 1997 8-hour ozone maintenance air quality State Implementation Plan (SIP) to replace the previously... Simulator (MOVES) emissions model. Ohio submitted the SIP revision request to EPA on January 11, 2013. DATES...

78 FR 34965 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; 1997 8-Hour Ozone...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-11

... Promulgation of Air Quality Implementation Plans; Ohio; 1997 8-Hour Ozone Maintenance Plan Revision; Motor... request by Ohio to revise the 1997 8-hour ozone maintenance air quality State Implementation Plan (SIP...) emissions model. Ohio submitted the SIP revision request to EPA on December 7, 2012. DATES: Comments must be...

78 FR 34906 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Lima 1997 8-Hour Ozone...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-11

... Promulgation of Air Quality Implementation Plans; Ohio; Lima 1997 8-Hour Ozone Maintenance Plan Revision to... Lima, Ohio 1997 8-hour ozone maintenance air quality State Implementation Plan (SIP) to replace motor... (MOVES) emissions model. Ohio submitted the SIP revision request to EPA on January 11, 2013. DATES: This...

Factors affecting strategic plan implementation using interpretive structural modeling (ISM).

PubMed

Bahadori, Mohammadkarim; Teymourzadeh, Ehsan; Tajik, Hamidreza; Ravangard, Ramin; Raadabadi, Mehdi; Hosseini, Seyed Mojtaba

2018-06-11

Purpose Strategic planning is the best tool for managers seeking an informed presence and participation in the market without surrendering to changes. Strategic planning enables managers to achieve their organizational goals and objectives. Hospital goals, such as improving service quality and increasing patient satisfaction cannot be achieved if agreed strategies are not implemented. The purpose of this paper is to investigate the factors affecting strategic plan implementation in one teaching hospital using interpretive structural modeling (ISM). Design/methodology/approach The authors used a descriptive study involving experts and senior managers; 16 were selected as the study sample using a purposive sampling method. Data were collected using a questionnaire designed and prepared based on previous studies. Data were analyzed using ISM. Findings Five main factors affected strategic plan implementation. Although all five variables and factors are top level, "senior manager awareness and participation in the strategic planning process" and "creating and maintaining team participation in the strategic planning process" had maximum drive power. "Organizational structure effects on the strategic planning process" and "Organizational culture effects on the strategic planning process" had maximum dependence power. Practical implications Identifying factors affecting strategic plan implementation is a basis for healthcare quality improvement by analyzing the relationship among factors and overcoming the barriers. Originality/value The authors used ISM to analyze the relationship between factors affecting strategic plan implementation.

Measuring the Implementation Fidelity of Student Affairs Programs: A Critical Component of the Outcomes Assessment Cycle

ERIC Educational Resources Information Center

Gerstner, Jerusha J.; Finney, Sara J.

2013-01-01

Implementation fidelity assessment provides a means of measuring the alignment between the planned program and the implemented program. Unfortunately, the implemented program can differ from the planned program, resulting in ambiguous inferences about the planned program's effectiveness (i.e., it is uncertain if poor results are due to an…

75 FR 10449 - Approval and Promulgation of Implementation Plans; Texas; Revisions to Chapter 116 Which Relate...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-08

... Promulgation of Implementation Plans; Texas; Revisions to Chapter 116 Which Relate to the Application Review... approve revisions to the Texas State Implementation Plan (SIP) submitted by the State of Texas to EPA on... implements the requirements of House Bill 3732, 80th Legislature (2007), and the Texas Health and Safety Code...

Compliance through pollution prevention opportunity assessments at Edwards AFB -- Development, results and lessons learned

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beutelman, H.P.; Lawrence, A.

1999-07-01

Edwards Air Force Base (AFB), located in the Mojave Desert of southern California, is required to comply with environmental requirements for air pollution emissions, hazardous waste disposal, and clean water. The resources required to meet these many compliance requirements represents an ever increasing financial burden to the base, and to the Department of Defense. A recognized superior approach to environmental management is to achieve compliance through a proactive pollution prevention (P2) program which mitigates, and when possible, eliminates compliance requirements and costs, while at the same time reducing pollution released to the environment. At Edwards AFB, the Environmental Management Officemore » P2 Branch developed and implemented a strategy that addresses this concept, better known as Compliance Through Pollution Prevention (CTP2). At the 91st AWMA Annual Meeting and Exhibition, Edwards AFB presented a paper on its strategy and implementation of its CTP2 concept. Part of that strategy and implementation included accomplishment of process specific focused P2 opportunity assessments (OAs). Starting in 1998, Edwards AFB initiated a CTP2 OA project where OAs were targeted on those operational processes, identified as compliance sites, that contributed most to the compliance requirements and costs at Edwards AFB. The targeting of these compliance sites was accomplished by developing a compliance matrix that prioritized processes in accordance with an operational risk management approach. The Edwards AFB CTP2 PPOA project is the first of its kind within the Air Force Material Command, and is serving as a benchmark for establishment of the CTP2 OA process.« less

24 CFR 598.605 - Implementation plan.

Code of Federal Regulations, 2010 CFR

2010-04-01

... URBAN DEVELOPMENT COMMUNITY FACILITIES URBAN EMPOWERMENT ZONES: ROUND TWO AND THREE DESIGNATIONS Empowerment Zone Grants § 598.605 Implementation plan. (a) Implementation plan content. An EZ must submit an... requirements that the state and local governments, as Empowerment Zone designees, have agreed to meet as...

An assessment of implementation and evaluation phases of strategic plans in Iranian hospitals.

PubMed

Sadeghifar, Jamil; Tofighi, Shahram; Roshani, Mohamad; Toulideh, Zahra; Mohsenpour, Seyedramezan; Jafari, Mehdi

2017-01-01

To assess the implementation and evaluation phases of strategic plans in selected hospitals. We conducted a cross-sectional study of implementation and evaluation of strategic plan in 24 hospitals in 2015, using a questionnaire which consisted of two separate sections for strategic implementation and strategic evaluation. Data were analyzed with SPSS version 18. Nearly one-third of hospitals claimed that they allocate their budget based on priorities and strategic goals. However, it turned out that although goals had been set, no formal announcements had been made. Most of the hospitals stated that they used measures when evaluating the plan. For hospital staff, clarifying the hospital's priorities was the most important advantage of a strategic plan. There is no clear definition for strategic management in Iranian hospitals, which results in chaotic implementation and control of strategic planning.

The Best Laid Plans: An Examination of School Plan Quality and Implementation in a School Improvement Initiative

ERIC Educational Resources Information Center

Strunk, Katharine O.; Marsh, Julie A.; Bush-Mecenas, Susan C.; Duque, Matthew R.

2016-01-01

Purpose: A common strategy used in school improvement efforts is a mandated process of formal planning, yet little is known about the quality of plans or the relationship between plan quality and implementation. This mixed-methods article investigates plan quality, factors associated with plan quality, and the relationship between plan quality and…

Maintenance of C sinks sustains enhanced C assimilation during long-term exposure to elevated [CO2] in Mojave Desert shrubs

USDA-ARS?s Scientific Manuscript database

During the first few years of elevated atmospheric [CO2] treatment at the Nevada Desert FACE Facility, photosynthetic downregulation was observed in desert shrubs grown under elevated [CO2], especially under relatively wet environmental conditions. Nonetheless, those plants maintained increased Asat...

EFFECTS OF ELEVATED CO2 ON FINE ROOT DYNAMICS IN A MOJAVE DESERT COMMUNITY: A FACE STUDY

EPA Science Inventory

Fine roots ('1 mm diameter) are critical in plant water and nutrient absorption, and it is important to understand how rising atmospheric CO2 will affect them as part of terrestrial ecosystem responses to global change. This study's objective was to determine the effects of elev...

Navajo Code Talker Joe Morris, Sr. shared insights from his time as a secret World War Two messenger

NASA Technical Reports Server (NTRS)

2002-01-01

Navajo Code Talker Joe Morris, Sr. shared insights from his time as a secret World War Two messenger with his audience at NASA's Dryden Flight Research Center on Nov. 26, 2002. NASA Dryden is located on Edwards Air Force Base in California's Mojave Desert.

Invasive species in southern Nevada [Chapter 4

Treesearch

Mathew L. Brooks; Steven M. Ostoja; Jeanne C. Chambers

2013-01-01

Southern Nevada contains a wide range of topographies, elevations, and climatic zones emblematic of its position at the ecotone between the Mojave Desert, Great Basin, and Colorado Plateau ecoregions. These varied environmental conditions support a high degree of biological diversity (Chapter 1), but they also provide opportunities for a wide range of invasive species...

Validation and Development of a Certification Program for Using K9s to Survey Desert Tortoises

DTIC Science & Technology

2011-08-01

Mojave Desert tortoises were reported on DOD land, in the Eastern Colorado recovery unit on the Chocolate Mountain Air Gunnery Range; sampling data...McCulloch, M. 2006. Diagnostic accuracy of canine scent detection in early- and late-stage lung and breast cancers. Integrative Cancer Therapies

Mechanisms for maintenance of dominance in a nonclonal desert shrub

Treesearch

Stanley G. Kitchen; Susan E. Meyer; Stephanie L. Carlson

2015-01-01

Blackbrush (Coleogyne ramosissima: Rosaceae) is a slow-growing, non-clonal shrub that is regionally dominant on xeric, shallow soils in the North American Mojave Desert-Great Basin transition zone and southern Colorado Plateau. Blackbrush seed production is concentrated in mast years, and most seeds are cached and later consumed by heteromyid rodents....

Response of birds to fire in the American southwest

Treesearch

Carl E. Bock; William M. Block

2005-01-01

Fire was a common prehistoric disturbance in most southwestern grasslands, oak savannas, and coniferous forests, but not in Sonoran and Mojave desertscrub, or in riparian ecosystems. Prescribed burning should be applied, but under experimental conditions that facilitate studying its impacts on birds and other components of biodiversity. Fire plays a critical role in...

78 FR 13374 - Notice of Public Meetings: Mojave-Southern Great Basin Resource Advisory Council, Nevada

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-27

... DEPARTMENT OF THE INTERIOR Bureau of Land Management [LLNV912000 L10100000.PH0000 LXSS0006F0000... Resource Advisory Council, Nevada AGENCY: Bureau of Land Management, Interior. ACTION: Notice of public meetings. SUMMARY: In accordance with the Federal Land Policy and Management Act (FLPMA) and the Federal...

76 FR 10914 - Notice of Public Meetings: Mojave-Southern Great Basin Resource Advisory Council, Nevada

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-28

... DEPARTMENT OF THE INTERIOR Bureau of Land Management [LLNV912000 L16400000.PH0000 LXSS006F0000... Resource Advisory Council, Nevada AGENCY: Bureau of Land Management, Interior. ACTION: Notice of public meetings. SUMMARY: In accordance with the Federal Land Policy and Management Act (FLPMA) and the Federal...

POPULATION STRUCTURE OF THE RED-SPOTTED TOAD, BUFO PUNCTATUS, IN A NATURALLY FRAGMENTED DESERT LANDSCAPE

EPA Science Inventory

We investigated the spatial scale at which genetic structure of Bufo punctatus within the Mojave

Desert is organized by sequencing a portion of mitochondrial DNA control region for 831 toads

collected from 43 sites around Las Vegas, Nevada. We grouped these collecti...

Coleogyne ramosissima Torr.: blackbrush

Treesearch

Burton K. Pendleton

2008-01-01

Blackbrush - Coleogyne ramosissima Torr. - grows in the transition zone between warm and cold deserts of southern California, southern Nevada, southern Utah, northern Arizona, and southwestern Colorado. It is found at elevations of 760 to 1,980 m. Ranging from 0.3 to 1.2 m in height, blackbrush forms almost monotypic stands in the lower Mojave-Great Basin ecotone,...

The floral hosts and distribution of a supposed creosote bush specialist, Colletes stepheni Timberlake (Hymenoptera: Colletidae)

USDA-ARS?s Scientific Manuscript database

Colletes stepheni Timberlake, previously thought to be a narrow oligolege of Larrea (creosote bush) of limited distribution in the Sonoran Desert, is found to be a much more widely distributed psammophile of the Sonoran, Mojave and Great Basin Deserts that utilizes two unrelated plant pollen sources...

The Riparianness of a Desert Herpetofauna

Treesearch

Charles H. Lowe

1989-01-01

Within the Mojave, Sonoran, and Chihuahuan Desert subdivisions of the North American Desert in the U.S., more than half of 143 total amphibian and reptilian species perform as riparian and/or wetland taxa. For the reptiles, but not the amphibians, there is a significant inverse relationship between riparianness (obligate through preferential and facultative to...

Plot- and landscape-level changes in climate and vegetation following defoliation of exotic saltcedar (Tamarix sp.) from the biocontrol agent Diorhabda carinulata along a stream in the Mojave Desert (USA)

USGS Publications Warehouse

Bateman, H.L.; Nagler, P.L.; Glenn, E.P.

2013-01-01

The biocontrol agent, northern tamarisk beetle (Diorhabda carinulata), has been used to defoliate non-native saltcedar (Tamarix spp.) in USA western riparian systems since 2001. Biocontrol has the potential to impact biotic communities and climatic conditions in affected riparian areas. To determine the relationships between biocontrol establishment and effects on vegetation and climate at the plot and landscape scales, we measured temperature, relative humidity, foliage canopy, solar radiation, and used satellite imagery to assess saltcedar defoliation and evapotranspiration (ET) along the Virgin River in the Mojave Desert. Following defoliation solar radiation increased, daily humidity decreased, and maximum daily temperatures tended to increase. MODIS and Landsat satellite imagery showed defoliation was widespread, resulting in reductions in ET and vegetation indices. Because biocontrol beetles are spreading into new saltcedar habitats on arid western rivers, and the eventual equilibrium between beetles and saltcedar is unknown, it is necessary to monitor trends for ecosystem functions and higher trophic-level responses in habitats impacted by biocontrol.

Composition of aeolian dust in natural traps on isolated surfaces of the central Mojave Desert - Insights to mixing, sources, and nutrient inputs

USGS Publications Warehouse

Reynolds, R.L.; Reheis, M.; Yount, J.; Lamothe, P.

2006-01-01

The recognition and characterization of aeolian dust in soil contribute to a better understanding of landscape and ecosystem dynamics of drylands. Results of this study show that recently deposited dust, sampled in isolated, mostly high-ground settings, is chemically and mineralogically similar on varied geologic substrates over a large area (15 000 km2) in the Mojave Desert. The silt-plus-clay fraction (fines) on these isolated surfaces is closely alike in magnetic-mineral composition, in contrast to greatly dissimilar magnetic compositions of rock surfaces of vastly different lithologies, on which the fines have accumulated. The fines, thus, are predominantly deposited dust. The amounts of potential nutrients in the sampled dust are much more uniform than might be provided by direct, local weathering of bedrock or by dust locally derived from nearby weathered products. The compositional similarity of the dust on these surfaces is interpreted to result from mixing of fines in the atmosphere as well as in fluvial, alluvial, and lacustrine depositional settings prior to dust emission.

MOJAVE. XV. VLBA 15 GHz Total Intensity and Polarization Maps of 437 Parsec-scale AGN Jets from 1996 to 2017

NASA Astrophysics Data System (ADS)

Lister, M. L.; Aller, M. F.; Aller, H. D.; Hodge, M. A.; Homan, D. C.; Kovalev, Y. Y.; Pushkarev, A. B.; Savolainen, T.

2018-01-01

We present 5321 mas-resolution total intensity and linear polarization maps of 437 active galactic nuclei (AGNs) obtained with the VLBA at 15 GHz as part of the MOJAVE survey, and also from the NRAO data archive. The former is a long-term program to study the structure and evolution of powerful parsec-scale outflows associated with AGNs. The targeted AGNs are drawn from several flux-limited radio and γ-ray samples, and all have correlated VLBA flux densities greater than ∼50 mJy at 15 GHz. Approximately 80% of these AGNs are associated with γ-ray sources detected by the Fermi LAT instrument. The vast majority were observed with the VLBA on 5–15 occasions between 1996 January 19 and 2016 December 26, at intervals ranging from a month to several years, with the most typical sampling interval being six months. A detailed analysis of the linear and circular polarization evolutions of these AGN jets is presented in the other papers in this series.

A New Geological Slip Rate Estimate for the Calico Fault, Eastern California: Implications for Geodetic Versus Geologic Rate Estimates in the Eastern California Shear Zone

NASA Astrophysics Data System (ADS)

Wetmore, P. H.; Xie, S.; Gallant, E.; Owen, L. A.; Dixon, T. H.

2017-12-01

Fault slip rate is fundamental to accurate seismic hazard assessment. In the Mojave Desert section of the Eastern California Shear Zone previous studies have suggested a discrepancy between short-term geodetic and long-term geologic slip rate estimates. Understanding the origin of this discrepancy could lead to better understanding of stress evolution, and improve earthquake hazard estimates in general. We measured offsets in alluvial fans along the Calico fault near Newberry Springs, California, and used exposure age dating based on the cosmogenic nuclide 10Be to date the offset landforms. We derive a mean slip rate of 3.6 mm/yr, representing an average over the last few hundred thousand years, significantly faster than previous estimates. Considering numerous faults in the Mojave Desert and limited geologic slip rate estimates, it is premature to claim a geologic versus geodetic "discrepancy" for the ECSZ. More slip rate data, from all faults with the ECSZ, are needed to provide a statistically meaningful assessment of the geologic rates for each of the faults comprising the ECSZ.

Analysis of tectonic features in US southwest from Skylab photographs

NASA Technical Reports Server (NTRS)

Abdel-Gawad, M. (Principal Investigator); Tubbesing, L.

1975-01-01

The author has identified the following significant results. Skylab photographs were utilized to study faults and tectonic lines in selected areas of the U.S. Southwest. Emphasis was on elements of the Texas Zone in the Mojave Desert and the tectonic intersection in southern Nevada. Transverse faults believed to represent the continuation of the Texas Zone were found to be anomalous in strike. This suggests that the Mojave Desert block was rotated counterclockwise as a unit with the Sierra Nevada. Left-lateral strike-slip faults in Lake Mead area are interpreted as elements of the Wasatch tectonic zone; their anomalous trend indicates that the Lake Mead area has rotated clockwise with the Colorado Plateau. A tectonic model relating major fault zones to fragmentation and rotation of crustal blocks was developed. Detailed correlation of the high resolution S190B metric camera photographs with U-2 photographs and geologic maps demonstrates the feasibility of utilizing S190B photographs for the identification of geomorphic features associated with recent and active faults and for the assessment of seismic hazards.

Genetic structure of Kurtzmaniella cleridarum, a cactus flower beetle yeast of the Sonoran and Mojave Deserts: speciation by distance?

PubMed

Lachance, Marc-André; Perri, Ami M; Farahbakhsh, Amy S; Starmer, William T

2013-11-01

We studied 95 isolates of the yeast species Kurtzmaniella cleridarum recovered from nitidulid beetles collected in flowers of cacti of the Sonoran Desert of southern Arizona and the Mojave Desert of California. They were characterized on the basis of mating type and ten polymorphic DNA markers in relation to their geographic distribution. Although all loci appeared to be free of strong linkage, the recovered haplotypes represented but a small fraction of possible combinations, indicating that abundant asexual reproduction of local genotypes accounts for much of population growth, even though the yeast is capable of sexual recombination in nature. Much of the genetic differentiation took place at the local level, indicating that gene flow across the various localities is limited. However, a relationship exists between overall genetic differentiation and geography over long distances. We estimated that populations separated by c. 1300 km would share no alleles in common and that such a separation might be enough to favor the onset of speciation. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

KSC-2013-2704

NASA Image and Video Library

2013-06-13

MOJAVE DESERT, Calif. – In the Mojave Desert in California, John Garvey, far right, describes his company's Prospector-18 rocket. Long Beach, Calif.-based Garvey Spacecraft Corp. built the rocket and its engine. Collectively known as CubeSats, the satellites will record shock, vibrations and heat inside the rocket. They will not be released during the test flight, but the results will be used to prove or strengthen their designs before they are carried into orbit in 2014 on a much larger rocket. A new, lightweight carrier is also being tested for use on future missions to deploy the small spacecraft. The flight also is being watched closely as a model for trying out new or off-the-shelf technologies quickly before putting them in the pipeline for use on NASA's largest launchers. Built by several different organizations, including a university, a NASA field center and a high school, the spacecraft are four-inch cubes designed to fly on their own eventually, but will remain firmly attached to the rocket during the upcoming mission. For more information, visit http://www.nasa.gov/mission_pages/smallsats/elana/cubesatlaunchpreview.html Photo credit: NASA/Dimitri Gerondidakis

Cooperative Collision Avoidance Technology Demonstration Data Analysis Report

NASA Technical Reports Server (NTRS)

2007-01-01

This report details the National Aeronautics and Space Administration (NASA) Access 5 Project Office Cooperative Collision Avoidance (CCA) Technology Demonstration for unmanned aircraft systems (UAS) conducted from 21 to 28 September 2005. The test platform chosen for the demonstration was the Proteus Optionally Piloted Vehicle operated by Scaled Composites, LLC, flown out of the Mojave Airport, Mojave, CA. A single intruder aircraft, a NASA Gulf stream III, was used during the demonstration to execute a series of near-collision encounter scenarios. Both aircraft were equipped with Traffic Alert and Collision Avoidance System-II (TCAS-II) and Automatic Dependent Surveillance Broadcast (ADS-B) systems. The objective of this demonstration was to collect flight data to support validation efforts for the Access 5 CCA Work Package Performance Simulation and Systems Integration Laboratory (SIL). Correlation of the flight data with results obtained from the performance simulation serves as the basis for the simulation validation. A similar effort uses the flight data to validate the SIL architecture that contains the same sensor hardware that was used during the flight demonstration.

The Paleogene California River: Evidence of Mojave-Uinta paleodrainage from U-Pb ages of detrital zircons

USGS Publications Warehouse

Davis, S.J.; Dickinson, W.R.; Gehrels, G.E.; Spencer, J.E.; Lawton, T.F.; Carroll, A.R.

2010-01-01

U-Pb age spectra of detrital zircons in samples from the Paleogene Colton Formation in the Uinta Basin of northeastern Utah and the Late Cretaceous McCoy Mountains Formation of southwestern Arizona (United States) are statistically indistinguishable. This finding refutes previous inferences that arkosic detritus of the Colton was derived from cratonic basement exposed by Laramide tectonism, and instead establishes the Cordilleran magmatic arc (which also provided sediment to the McCoy Mountains Formation) as the primary source. Given the existence of a north-south-trending drainage divide in eastern Nevada and the north-northeast direction of Laramide paleoflow throughout Arizona and southern Utah, we infer that a large river system headed in the arc of the Mojave region flowed northeast ~700 km to the Uinta Basin. Named after its source area, this Paleogene California River would have been equal in scale but opposite in direction to the modern Green River-Colorado River system, and the timing and causes of the subsequent drainage reversal are important constraints on the tectonic evolution of the Cordillera and the Colorado Plateau. ?? 2010 Geological Society of America.

Sample-Based Motion Planning in High-Dimensional and Differentially-Constrained Systems

DTIC Science & Technology

2010-02-01

Reachable Set . . . 88 6-1 LittleDog Robot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 6-2 Dog bounding up stairs ...planning algorithm implemented on LittleDog, a quadruped robot . The motion planning algorithm successfully planned bounding trajectories over extremely...a motion planning algorithm implemented on LittleDog, a quadruped robot . The motion planning algorithm successfully planned bounding trajectories

Strategic planning, implementation, and evaluation processes in hospital systems: a survey from Iran.

PubMed

Sadeghifar, Jamil; Jafari, Mehdi; Tofighi, Shahram; Ravaghi, Hamid; Maleki, Mohammad Reza

2014-09-28

Strategic planning has been presented as an important management practice. However, evidence of its deployment in healthcare systems in low-income and middle-income countries (LMICs) is limited. This study investigated the strategic management process in Iranian hospitals. The present study was accomplished in 24 teaching hospitals in Tehran, Iran from September 2012 to March 2013. The data collection instrument was a questionnaire including 130 items. This questionnaire measured the situation of formulation, implementation, and evaluation of strategic plan as well as the requirements, facilitators, and its benefits in the studied hospitals. All the investigated hospitals had a strategic plan. The obtained percentages for the items "the rate of the compliance to requirements" and "the quantity of planning facilitators" (68.75%), attention to the stakeholder participation in the planning (55.74%), attention to the planning components (62.22%), the status of evaluating strategic plan (59.94%) and the benefits of strategic planning for hospitals (65.15%) were in the medium limit. However, the status of implementation of the strategic plan (53.71%) was found to be weak. Significant statistical correlations were observed between the incentive for developing strategic plan and status of evaluating phase (P=0.04), and between status of implementation phase and having a documented strategic plan (P=0.03). According to the results, it seems that absence of appropriate internal incentive for formulating and implementing strategies led more hospitals to start formulation strategic planning in accordance with the legal requirements of Ministry of Health. Consequently, even though all the investigated hospital had the documented strategic plan, the plan has not been implemented efficiently and valid evaluation of results is yet to be achieved.

Strategic Planning, Implementation, and Evaluation Processes in Hospital Systems: A Survey From Iran

PubMed Central

Sadeghifar, Jamil; Jafari, Mehdi; Tofighi, Shahram; Ravaghi, Hamid; Maleki, Mohammad Reza

2015-01-01

Aim & Background: Strategic planning has been presented as an important management practice. However, evidence of its deployment in healthcare systems in low-income and middle-income countries (LMICs) is limited. This study investigated the strategic management process in Iranian hospitals. Methods: The present study was accomplished in 24 teaching hospitals in Tehran, Iran from September 2012 to March 2013. The data collection instrument was a questionnaire including 130 items. This questionnaire measured the situation of formulation, implementation, and evaluation of strategic plan as well as the requirements, facilitators, and its benefits in the studied hospitals. Results: All the investigated hospitals had a strategic plan. The obtained percentages for the items “the rate of the compliance to requirements” and “the quantity of planning facilitators” (68.75%), attention to the stakeholder participation in the planning (55.74%), attention to the planning components (62.22%), the status of evaluating strategic plan (59.94%) and the benefits of strategic planning for hospitals (65.15%) were in the medium limit. However, the status of implementation of the strategic plan (53.71%) was found to be weak. Significant statistical correlations were observed between the incentive for developing strategic plan and status of evaluating phase (P=0.04), and between status of implementation phase and having a documented strategic plan (P=0.03). Conclusion: According to the results, it seems that absence of appropriate internal incentive for formulating and implementing strategies led more hospitals to start formulation strategic planning in accordance with the legal requirements of Ministry of Health. Consequently, even though all the investigated hospital had the documented strategic plan, the plan has not been implemented efficiently and valid evaluation of results is yet to be achieved. PMID:25716385

75 FR 61369 - Revisions to the California State Implementation Plan; Sacramento Metropolitan Air Quality...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-05

... the California State Implementation Plan; Sacramento Metropolitan Air Quality Management District... approve a revision to the Sacramento Metropolitan Air Quality Management District's portion of the... Metropolitan Air Quality Management District (SMAQMD) adopted the ``Ozone State Implementation Plan Revision...

76 FR 48006 - Limited Federal Implementation Plan; Prevention of Significant Deterioration; California; North...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-08

... Implementation Plan; Prevention of Significant Deterioration; California; North Coast Unified Air Quality Management District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing a limited Federal Implementation Plan (FIP) for the North Coast Unified Air Quality Management...

76 FR 34630 - Approval and Promulgation of Implementation Plans; New Hampshire: Prevention of Significant...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-14

... Promulgation of Implementation Plans; New Hampshire: Prevention of Significant Deterioration; Greenhouse Gas... greenhouse gas (GHG) emissions. This rule clarifies the applicable thresholds in the New Hampshire SIP... Significant Deterioration Provisions Concerning Greenhouse Gas Emitting-Sources in State Implementation Plans...

75 FR 2090 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Volatile Organic Compound...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-14

... Promulgation of Air Quality Implementation Plans; Indiana; Volatile Organic Compound Automobile Refinishing... automobile refinishing rule for approval into its State Implementation Plan (SIP). These rule revisions extend the applicability of Indiana's approved volatile organic compound (VOC) automobile refinishing...

Climate Action Planning Process | Climate Neutral Research Campuses | NREL

Science.gov Websites

Action Planning Process Climate Action Planning Process For research campuses, NREL has developed a five-step process to develop and implement climate action plans: Determine baseline energy consumption Analyze technology options Prepare a plan and set priorities Implement the climate action plan Measure and

Some Methods for Evaluating Program Implementation.

ERIC Educational Resources Information Center

Hardy, Roy A.

An approach to evaluating program implementation is described. This approach includes the development of a project description which includes a structure matrix, sampling from the structure matrix, and preparing an implementation evaluation plan. The implementation evaluation plan should include: (1) verification of implementation of planned…

78 FR 16825 - Approval of Air Quality Implementation Plans; Navajo Nation; Regional Haze Requirements for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-19

... Quality Implementation Plans; Navajo Nation; Regional Haze Requirements for Navajo Generating Station... source-specific federal implementation plan (FIP) requiring the Navajo Generating Station (NGS), located... . SUPPLEMENTARY INFORMATION: Throughout this document, ``we'', ``us'', and ``our'' refer to EPA. Table of Contents...

33 CFR 385.30 - Master Implementation Sequencing Plan.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Master Implementation Sequencing... Incorporating New Information Into the Plan § 385.30 Master Implementation Sequencing Plan. (a) Not later than... of Environmental Protection, and other Federal, State, and local agencies, develop a Master...

33 CFR 385.30 - Master Implementation Sequencing Plan.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Master Implementation Sequencing... Incorporating New Information Into the Plan § 385.30 Master Implementation Sequencing Plan. (a) Not later than... of Environmental Protection, and other Federal, State, and local agencies, develop a Master...

33 CFR 385.30 - Master Implementation Sequencing Plan.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Master Implementation Sequencing... Incorporating New Information Into the Plan § 385.30 Master Implementation Sequencing Plan. (a) Not later than... of Environmental Protection, and other Federal, State, and local agencies, develop a Master...

78 FR 52485 - Revisions to the Arizona State Implementation Plan, Maricopa County Area

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-23

...] Revisions to the Arizona State Implementation Plan, Maricopa County Area AGENCY: Environmental Protection... County Area portion of the Arizona State Implementation Plan (SIP). These revisions concern particulate matter (PM) emissions from fugitive dust sources. We are approving local statutes that regulate these...

78 FR 63383 - Approval and Promulgation of Air Quality Implementation Plans; Rhode Island: Prevention of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-24

...] Approval and Promulgation of Air Quality Implementation Plans; Rhode Island: Prevention of Significant... revisions to the Rhode Island State Implementation Plan (SIP) primarily relating to regulation of Greenhouse Gases (GHGs) under Rhode Island's Prevention of Significant Deterioration (PSD) preconstruction...

76 FR 4835 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Volatile Organic Compound...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-27

... Promulgation of Air Quality Implementation Plans; Ohio; Volatile Organic Compound Reinforced Plastics...) emissions from reinforced plastic composites production operations to Ohio's State Implementation plan (SIP). This rule applies to any facility that has reinforced plastic composites production operations. This...

75 FR 24404 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Volatile Organic Compound...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-05

... Promulgation of Air Quality Implementation Plans; Indiana; Volatile Organic Compound Automobile Refinishing... approving into the Indiana State Implementation Plan (SIP) amendments to Indiana's automobile refinishing... (VOC) automobile refinishing rules to all persons in Indiana who sell or manufacture automobile...

77 FR 24160 - Revisions to the Hawaii State Implementation Plan

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-23

... the Hawaii State Implementation Plan AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the Hawaii State Implementation Plan (SIP... Hawaii SIP in 1983. DATES: Any comments on this proposal must arrive by May 23, 2012. ADDRESSES: Submit...

76 FR 5203 - Draft Environmental Impact Statement, Stehekin River Corridor Implementation Plan, North Cascades...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-28

... Statement, Stehekin River Corridor Implementation Plan, North Cascades National Park Service Complex; Chelan... public comment period. SUMMARY: The National Park Service, in cooperation with the Federal Highway Administration, has prepared a combined Stehekin River Corridor Implementation Plan, Lake Chelan National...

75 FR 34669 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; Transportation...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-18

... Promulgation of Air Quality Implementation Plans; Maryland; Transportation Conformity Regulations AGENCY... Implementation Plan (SIP) revision submitted by Maryland for Transportation Conformity Regulations. In the Final Rules section of this Federal Register, EPA is approving the State's SIP submittal as a direct final...

76 FR 59344 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; Transportation...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-26

... Promulgation of Air Quality Implementation Plans; Maryland; Transportation Conformity Regulations AGENCY... Implementation Plan (SIP) revision submitted by Maryland to establish transportation conformity regulations. In the Final Rules section of this Federal Register, EPA is approving the State's SIP submittal as a...

40 CFR 93.120 - Consequences of control strategy implementation plan failures.

Code of Federal Regulations, 2010 CFR

2010-07-01

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Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-26

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Differentiation of Secular and Postseismic Deformation in the Mojave Shear Zone in Southern California and Inference of Lithospheric Rheology

NASA Astrophysics Data System (ADS)

Shen, Z.; Liu, S.; Burgmann, R.

2015-12-01

The 1992 Mw 7.3 Landers and 1999 Mw7.1 Hector Mine earthquakes struck the Eastern California Shear Zone (ECSZ) in the Mojave Desert, Southern California. Coseismic and postseismic deformation from these events affect efforts to use Global Positioning System (GPS) observations collected since these events to establish a secular surface velocity field, especially in the near field of the coseismic ruptures. We devise block motion models constrained by both historical pre-Landers triangulation and trilateration observations and post-Landers GPS measurements to recover the secular deformation field and differentiate the postseismic transients in the Mojave region. Postseismic transients are found to remain in various "interseismic" GPS velocity solutions in the form of 2-3 mm/yr excess right-lateral shear across the Landers and Hector Mine coseismic ruptures [Liu et al., 2015 JGR]. Postseismic GPS time series differentiated from the secular velocity field reveal enduring late-stage transient motions in the near field of the coseismic ruptures. Using the postseismic time series data as model constraints, we develop postseismic deformation model invoking afterlip on faults and viscoelastic relaxation in the lower crust and upper mantle. A Burgers body material and a Maxwell material are assumed for the lower crust and upper mantle respectively. Our preliminary modeling result, constrained using GPS time series data from the SCEC Crustal Motion Map 4.0 (covering the time period of 1992-2004), reveals that both the long-term viscosities for the lower crust and upper mantle are on the order of e+19 Pa-s. This finding differs significantly from the "Crème Brulee" model predictions about the rheological structure of the lower crust and upper mantle, in which the lower crust has a substantially higher viscosity. We are incorporating more GPS time series data into our model, particularly the ones from continuous sites of the Plate Boundary Observatory network with post-2004 time span, and the modeling result will be presented at the meeting.

Mesozoic intra-arc tectonics in the NE Mojave Desert, CA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stephens, K.A.; Schermer, E.R.; Walker, J.D.

1993-04-01

Field and U-Pb zircon geochronological data from the Tiefort Mts. (TM) and surrounding areas in the NE Mojave Desert provide new constraints on Precambrian to Paleozoic paleogeography and Mesozoic intra-arc tectonics. Amphibolite facies metasediments appear to correlate with lower Paleozoic miogeoclinal sequences. Coarse-grained K-feldspar augen gneiss occurs in sharp contact with the metasedimentary rocks; U-Pb dating yields a 1393[+-]12 Ma age. This gneiss is interpreted to represent cratonal basement of North America. A texturally and compositionally heterogeneous amphibolite-facies monzonitic complex which intrudes the basement and metasediments yields a mid-Jurassic age. Felsite and biotite granite that intrude the foliated monzonitic complexmore » locally contain the mylonitic fabric and appear to be syn-late kinematic. Undeformed pegmatite, granite, and microdiorite appear as dikes throughout the region. Vertical silicic dikes at southern TM trend N5-25E and are dated at 148[+-]14 Ma, coeval with the Independence dike swarm (IDS). Similar dikes that occur at TM trend N60-80E. Undeformed granite cross-cuts the foliated monzonite; some granitic rocks cut dikes of the IDs and are likely to be Cretaceous in age. The E- to SE-vergence and mid-late Jurassic age of ductile shear zones in the TM region are similar to that in nearby parts of the East Sierra Thrust System (ESTS). If NE and NNE dikes are IDS-equivalent, this implies clockwise, vertical-axis rotation of 30[degree]--90[degree] by younger structures. The authors interpret this to be related to late Cenozoic strike-slip faults. Restoration of folds and the IDS to the regional NW trend results in top to the E to NE sense of shear during Jurassic deformation. Deformation in the TM and areas to the north connects the ESTS from the Garlock fault to the central Mojave region indicating a region in which mid-crustal levels of the arc and cratonal basement experienced contractional tectonism during mid-Jurassic time.« less

Effects of climatic variation on field metabolism and water relations of desert tortoises

USGS Publications Warehouse

Henen, B.T.; Peterson, C.C.; Wallis, I.R.; Berry, K.H.; Nagy, K.A.

1998-01-01

We used the doubly labeled water method to measure the field metabolic rates (FMRs, in kJ kg-1 day-1) and water flux rates (WIRs, in ml H2O kg-1 day-1) of adult desert tortoises (Gopherus agassizii) in three parts of the Mojave Desert in California over a 3.5-year period, in order to develop insights into the physiological responses of this threatened species to climate variation among sites and years. FMR, WIR, and the water economy index (WEI, in ml H2O kJ-1, an indicator of drinking of free water) differed extensively among seasons, among study sites, between sexes, and among years. In high-rainfall years, males had higher FMRs than females. Average daily rates of energy and water use by desert tortoises were extraordinarily variable: 28-fold differences in FMR and 237-fold differences in WIR were measured. Some of this variation was due to seasonal conditions, with rates being low during cold winter months and higher in the warm seasons. However, much of the variation was due to responses to year-to-year variation in rainfall. Annual spring peaks in FMR and WIR were higher in wet years than in drought years. Site differences in seasonal patterns were apparently due to geographic differences in rainfall patterns (more summer rain at eastern Mojave sites). In spring 1992, during an El Nino (ENSO) event, the WEI was greater than the maximal value obtainable from consuming succulent vegetation, indicating copious drinking of rainwater at that time. The physiological and behavioral flexibility of desert tortoises, evident in individuals living at all three study sites, appears central to their ability to survive droughts and benefit from periods of resource abundance. The strong effects of the El Nino (ENSO) weather pattern on tortoise physiology, reproduction, and survival elucidated in this and other studies suggest that local manifestations of global climate events could have a long-term influence on the tortoise populations in the Mojave Desert.

Variation in the establishment of a non-native annual grass influences competitive interactions with Mojave Desert perennials

USGS Publications Warehouse

DeFalco, L.A.; Fernandez, G.C.J.; Nowak, R.S.

2007-01-01

Competition between native and non-native species can change the composition and structure of plant communities, but in deserts, the highly variable timing of resource availability also influences non-native plant establishment, thus modulating their impacts on native species. In a field experiment, we varied densities of the non-native annual grass Bromus madritensis ssp. rubens around individuals of three native Mojave Desert perennials-Larrea tridentata, Achnatherum hymenoides, and Pleuraphis rigida-in either winter or spring. For comparison, additional plots were prepared for the same perennial species and seasons, but with a mixture of native annual species as neighbors. Growth of perennials declined when Bromus was established in winter because Bromus stands had 2-3 months of growth and high water use before perennial growth began. However, water potentials for the perennials were not significantly reduced, suggesting that direct competition for water may not be the major mechanism driving reduced perennial growth. The impact of Bromus on Larrea was lower than for the two perennial grasses, likely because Larrea maintains low growth rates throughout the year, even after Bromus has completed its life cycle. This result contrasts with the perennial grasses, whose phenology completely overlaps with (Achnatherum) or closely follows (Pleuraphis) that of Bromus. In comparison, Bromus plants established in spring were smaller than those established in winter and thus did not effectively reduce growth of the perennials. Growth of perennials with mixed annuals as neighbors also did not differ from those with Bromus neighbors of equivalent biomass, but stands of these native annuals did not achieve the high biomass of Bromus stands that were necessary to reduce perennial growth. Seed dormancy and narrow requirements for seedling survivorship of native annuals produce densities and biomass lower than those achieved by Bromus; thus, impacts of native Mojave Desert annuals on perennials are expected to be lower than those of Bromus. ?? 2006 Springer Science+Business Media B.V.

Eolian sand transport pathways in the southwestern United States: Importance of the Colorado River and local sources

USGS Publications Warehouse

Muhs, D.R.; Reynolds, R.L.; Been, J.; Skipp, G.

2003-01-01

Geomorphologists have long recognized that eolian sand transport pathways extend over long distances in desert regions. Along such pathways, sediment transport by wind can surmount topographic obstacles and cross major drainages. Recent studies have suggested that three distinct eolian sand transport pathways exist (or once existed) in the Mojave and Sonoran Desert regions of the southwestern United States. One hypothesized pathway is colian sand transport from the eastern Mojave Desert of California into western Arizona, near Parker, and would require sand movement across what must have been at least a seasonally dry Colorado River valley. We tested this hypothesis by mineralogical, geochemical and magnetic analyses of eolian sands on both sides of the Colorado River, as well as sediment from the river itself. Results indicate that dunes on opposite sides of the Colorado River are mineralogically distinct: eastern California dunes are feldspar-rich whereas western Arizona dunes are quartz-rich, derived from quartz-rich Colorado River sediments. Because of historic vegetation changes, little new sediment from the Colorado River is presently available to supply the Parker dunes. Based on this study and previous work, the Colorado River is now known to be the source of sand for at least three of the major dune fields of the Sonoran Desert of western Arizona and northern Mexico. On the other hand, locally derived alluvium appears to be a more important source of dune fields in the Mojave Desert of California. Although many geomorphologists have stressed the importance of large fluvial systems in the origin of desert dune fields, few empirical data actually exist to support this theory. The results presented here demonstrate that a major river system in the southwestern United States is a barrier to the migration of some dune fields, but essential to the origin of others. Published by Elsevier Science Ltd.

Contrasting oxidative stress response mechanisms in novel strains of Bacillus isolated from the Mars-analog, Mojave Desert

NASA Astrophysics Data System (ADS)

Lera, M.; Marcu, O.

2011-12-01

Environmental conditions that limit the presence of life include ionizing radiation, extreme temperatures, and lack of water. These environments are common in our solar system and may contribute to the lack of apparent life. However, analogous environments here on Earth are host to a multitude of thriving microbial life. In order for microbes to survive in dry deserts, they must be must be able to adapt to transient diurnal and seasonal changes in the environment (water, temperature). To uncover response strategies to environmental stress that may prevent cellular damage and ensure adaptation and survival, two distinct, novel strains of Bacillus were isolated from the Mojave Desert (a Mars analog due to its arid conditions and high incidence of ultraviolet light) and classified by their partial 16S RNA gene sequences. These species, despite being closely related, exhibited radically different phenotypes and contrasting strategies for mitigating stress. The two strains had different growth rates, metabolic capacities and sporulation onset times when challenged by crowding and heat-shock. In response to hydrogen peroxide challenge, the intracellular levels of catalase activity, a peroxide-scavenging enzyme, differed for each strain, and were surprisingly lower than that of a non-desert control species of Bacillus. DNA repair mechanisms were more active in one strain than the other, and one isolate responded with an increase in expression of longevity gene orthologs involved in stress response. After multiple rounds of culturing, the peroxide degradation capacity, as well as the growth and sporulation rates remained constant for each strain, which suggests these are permanent features of each strain rather than transient responses. Taken together, these data uncover a diverse arsenal of response mechanisms employed by closely related species to combat stress. These adaptations may provide environmental-niche specificity and the diversity of life even in a scarce environment like the Mojave Desert.