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This study achieves the first high-spatial-resolution, layer-scale, measured stratigraphic column of the Martian north polar layered deposits using a 1m-posting DEM. The marker beds found throughout the upper North Polar Layered Deposits range in thickness from 1.6 m-16.0 m +/-1.4 m, and 6 of 13 marker beds are separated by ???25-35 m. Thin-layer sets have average layer separations of 1.6 m. These layer separations may account for the spectral-power-peaks found in previous brightness-profile analyses. Marker-bed layer thicknesses show a weak trend of decreasing thickness with depth that we interpret to potentially be the result of a decreased accumulation rate in the past, for those layers. However, the stratigraphic...
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Effective monitoring of native bee populations requires accurate estimates of population size and relative abundance among habitats. Current bee survey methods, such as netting or pan trapping, may be adequate for a variety of study objectives but are limited by a failure to account for imperfect detection. Biases due to imperfect detection could result in inaccurate abundance estimates or erroneous insights about the response of bees to different environments. To gauge the potential biases of currently employed survey methods, we compared abundance estimates of bumblebees (Bombus spp.) derived from hierarchical distance sampling models (HDS) to bumblebee counts collected from fixed‐area net surveys (“net counts”)...
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Using data from the High Resolution Imaging Science Experiment (HiRISE) aboard the Mars Reconnaissance Orbiter, we reassess the methods by which layers within the north polar layered deposits (NPLD) can be delineated and their thicknesses measured. Apparent brightness and morphology alone are insufficient for this task; high resolution topographic data are necessary. From these analyses, we find that the visible appearance of layers depends to a large degree on the distribution of younger, mantling deposits (which in turn is partially influenced by inherent layer properties) and on the shape and location of the particular outcrop. This younger mantle partially obscures layer morphology and brightness and is likely...
Categories: Publication; Types: Citation; Tags: Icarus
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Grasslands comprise a small part of the Chihuahuan Desert but are vital to the biological diversity of the ecoregion. Characteristic grasses of the Chihuahuan Desert are tobosa (Pleuraphis mutica) and black grama (Bouteloua eriopoda) but other common species include alakali sacaton (Sporobolus airoides), big alkali sacaton (S. wrightii), mesa dropseed (S. flexuosus), blue grama (B. gracilis), sideoats grama (B. curtipendula ), hairy grama (B. hirsuta), slender grama (B. filiformis), chino grama (B. brevista), spruce top grama (B. chondrosioides), bush muhly (Muhlenbergia porteri), several three awns (Aristida spp.), and fluff grass (Dasyochloa pulchela) (Johnson 1974, Dinerstein et al. 2000). Many of the sites discussed...
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This file represents the final version of an assessment of the extent, condition, and distribution of grassland types in Arizona as indicated by expert interviews and field verification. Coverage includes the state of Arizona, Southwestern portions of the state of New Mexico, and the Northern portion of Sonora, Mexico.
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The Desert Renewable Energy Conservation Plan (DRECP), a major component of California's renewable energy planning efforts, will help provide effective protection and conservation of desert ecosystems while allowing for the appropriate development of renewable energy projects. The DRECP is focused on the desert regions and adjacent lands of seven California counties - Imperial, Inyo, Kern, Los Angeles, Riverside, San Bernardino, and San Diego. It is being prepared through an unprecedented collaborative effort between the California Energy Commission, California Department of Fish and Wildlife, the U.S. Bureau of Land Management, and the U.S. Fish and Wildlife Service also known as the Renewable Energy Action Team....
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Natural landscapes in the Southwestern United States are changing. In recent decades, rising temperatures and drought have led to drier conditions, contributed to large-scale ecological impacts, and affected many plant and animal species across the region. The current and future trajectory of climate change underscores the need for managers and conservation professionals to understand the impacts of these patterns on natural resources. In this regional assessment of the Southwest Climate Change Initiative, we evaluate changes in annual average temperatures from 1951–2006 across major habitats and large watersheds and compare these changes to the number of species of conservation concern that are found within these...
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Vegetation and land-cover changes are not always directional but follow complex trajectories over space and time, driven by changing anthropogenic and abiotic conditions. We present a multi-observational approach to land-change analysis that addresses the complex geographic and temporal variability of vegetation changes related to climate and land use. Using land-ownership data as a proxy for land-use practices, multitemporal land-cover maps, and repeat photography dating to the late 19th century, we examine changing spatial and temporal distributions of two vegetation types with high conservation value in the southwestern United States: grasslands and riparian vegetation. In contrast to many reported vegetation...
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This tile of the 3D Elevation Program (3DEP) seamless products is 1/3 arc-second resolution. 3DEP data serve as the elevation layer of The National Map, and provide basic elevation information for Earth science studies and mapping applications in the United States. Scientists and resource managers use 3DEP data for global change research, hydrologic modeling, resource monitoring, mapping and visualization, and many other applications. 3DEP data compose an elevation dataset that consists of seamless layers and a high resolution layer. Each of these layers consists of the best available raster elevation data of the conterminous United States, Alaska, Hawaii, territorial islands, Mexico and Canada. 3DEP data are updated...
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This tile of the 3D Elevation Program (3DEP) seamless products is 1/3 arc-second resolution. 3DEP data serve as the elevation layer of The National Map, and provide basic elevation information for Earth science studies and mapping applications in the United States. Scientists and resource managers use 3DEP data for global change research, hydrologic modeling, resource monitoring, mapping and visualization, and many other applications. 3DEP data compose an elevation dataset that consists of seamless layers and a high resolution layer. Each of these layers consists of the best available raster elevation data of the conterminous United States, Alaska, Hawaii, territorial islands, Mexico and Canada. 3DEP data are updated...
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Excavating into the shallow Martian subsurface has the potential to expose stratigraphic layers and mature regolith, which may hold a record of more ancient aqueous interactions than those expected under current Martian surface conditions. During the Spirit rover's exploration of Gusev crater, rover wheels were used to dig three trenches into the subsurface regolith down to 6-11 cm depth: Road Cut, the Big Hole, and The Boroughs. A high oxidation state of Fe and high concentrations of Mg, S, Cl, and Br were found in the subsurface regolith within the two trenches on the plains, between the Bonneville crater and the foot of Columbia Hills. Data analyses on the basis of geochemistry and mineralogy observations suggest...
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Panoramic Camera (Pancam) images from Meridiani Planum reveal a low-albedo, generally flat, and relatively rock-free surface. Within and around impact craters and fractures, laminated outcrop rocks with higher albedo are observed. Fine-grained materials include dark sand, bright ferric iron-rich dust, angular rock clasts, and millimeter-size spheroidal granules that are eroding out of the laminated rocks. Spectra of sand, clasts, and one dark plains rock are consistent with mafic silicates such as pyroxene and olivine. Spectra of both the spherules and the laminated outcrop materials indicate the presence of crystalline ferric oxides or oxyhydroxides. Atmospheric observations show a steady decline in dust opacity...
Categories: Publication; Types: Citation; Tags: Science
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A multidisciplinary study of a crude-oil contaminated aquifer shows that the distribution of microbial physiologic types is strongly controlled by the aquifer properties and crude oil location. The microbial populations of four physiologic types were analyzed together with permeability, pore-water chemistry, nonaqueous oil content, and extractable sediment iron. Microbial data from three vertical profiles through the anaerobic portion of the contaminated aquifer clearly show areas that have progressed from iron-reduction to methanogenesis. These locations contain lower numbers of iron reducers, and increased numbers of fermenters with detectable methanogens. Methanogenic conditions exist both in the area contaminated...
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Methyl tert-butyl ether (MTBE), the widely used gasoline oxygenate, has been identified as a common ground water contaminant, and BTEX compounds (benzene, toluene, ethylbenzene, and xylenes) have long been associated with gasoline spills. Because not all instances of ground water contamination by MTBE and BTEX can be attributed to spills or leaking storage tanks, other potential sources need to be considered. In this study, used motor oil was investigated as a potential source of these contaminants. MTBE in oil was measured directly by methanol extraction and gas chromatography using a flame ionization detector (GC/FID). Water was equilibrated with oil samples and analyzed for MTBE, BTEX, and the oxygenate tert-amyl...
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Tucked in a grove of thorny mesquite trees, on an ancient coral reef on the south side of the Hawaiian island of Oahu, west of Pearl Harbor, a small unmanned observatory quietly records the Earth’s time-varying magnetic field. The Honolulu Magnetic Observatory is 1 of 14 that the U.S. Geological Survey Geomag­netism Program operates at various locations across the United States and its territories.Data from these observatories, Honolulu, and those operated by institutions in foreign countries, record a variety of magnetic signals related to a wide diversity of physical phenomena in the Earth’s interior and its surrounding outer-space environment. USGS magnetic observatory operations are an integral part of a U.S....
Categories: Publication; Types: Citation; Tags: Fact Sheet
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This data set contains imagery from the National Agriculture Imagery Program (NAIP). The NAIP program is administered by USDA FSA and has been established to support two main FSA strategic goals centered on agricultural production. These are increase stewardship of America's natural resources while enhancing the environment, and to ensure commodities are procured and distributed effectively and efficiently to increase food security. The NAIP program supports these goals by acquiring and providing ortho imagery that has been collected during the agricultural growing season in the U.S. The NAIP ortho imagery is tailored to meet FSA requirements and is a fundamental tool used to support FSA farm and conservation programs....
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The ACS is a national, publicly available survey provided by the U.S. Census Bureau that collects information about population, education, housing, economic status, and more. Planners, public officials, entrepreneurs, and researchers rely on the data collected through this survey to help understand community conditions and to support community planning efforts.
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Systematic conservation planning is well suited to address the many large-scale biodiversity conservation challenges facing the Appalachian region. However, broad, well-connected landscapes will be required to sustain many of the natural resources important to this area into the future. If these landscapes are to be resilient to impending change, it will likely require an orchestrated and collaborative effort reaching across jurisdictional and political boundaries. The first step in realizing this vision is prioritizing discrete places and actions that hold the greatest promise for the protection of biodiversity. Five conservation design elements covering many critical ecological processes and patterns across the...
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This data set contains imagery from the National Agriculture Imagery Program (NAIP). The NAIP program is administered by USDA FSA and has been established to support two main FSA strategic goals centered on agricultural production. These are, increase stewardship of America's natural resources while enhancing the environment, and to ensure commodities are procured and distributed effectively and efficiently to increase food security. The NAIP program supports these goals by acquiring and providing ortho imagery that has been collected during the agricultural growing season in the U.S. The NAIP ortho imagery is tailored to meet FSA requirements and is a fundamental tool used to support FSA farm and conservation programs....


map background search result map search result map Desert Renewable Energy Conservation Plan Extent and Condition of Grasslands in Arizona, Northern Mexico, and Southwestern New Mexico Status and Distribution of Chihuahuan Desert Grasslands in the United States and Mexico Managing Changing Landscapes in the Southwestern United States Historical and Contemporary Geographic Data Reveal Complex Spatial and Temporal Responses of Vegetation to Climate and Land Stewardship Appalachian LCC Landscape Conservation Design Phase 1 Local Build-outs American Community Survey (ACS) : Population Density per Square Mile (2013) USGS NED 1/3 arc-second n65w148 1 x 1 degree GridFloat 2018 FSA 10:1 NAIP Imagery m_4609449_nw_15_1_20150810_20151201 3.75 x 3.75 minute JPEG2000 from The National Map FSA 10:1 NAIP Imagery m_3508305_se_17_1_20140504_20140710 3.75 x 3.75 minute JPEG2000 from The National Map USGS NED 1/3 arc-second n37w083 1 x 1 degree ArcGrid 2018 FSA 10:1 NAIP Imagery m_4609449_nw_15_1_20150810_20151201 3.75 x 3.75 minute JPEG2000 from The National Map FSA 10:1 NAIP Imagery m_3508305_se_17_1_20140504_20140710 3.75 x 3.75 minute JPEG2000 from The National Map USGS NED 1/3 arc-second n65w148 1 x 1 degree GridFloat 2018 USGS NED 1/3 arc-second n37w083 1 x 1 degree ArcGrid 2018 Historical and Contemporary Geographic Data Reveal Complex Spatial and Temporal Responses of Vegetation to Climate and Land Stewardship Desert Renewable Energy Conservation Plan Extent and Condition of Grasslands in Arizona, Northern Mexico, and Southwestern New Mexico Managing Changing Landscapes in the Southwestern United States Status and Distribution of Chihuahuan Desert Grasslands in the United States and Mexico American Community Survey (ACS) : Population Density per Square Mile (2013) Appalachian LCC Landscape Conservation Design Phase 1 Local Build-outs