Filters: Tags: permafrost (X)
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Potential Evapotranspiration (PET): These data represent decadal mean totals of potential evapotranspiration estimates (mm). The file name specifies the decade the raster represents. For example, a file named pet_mean_mm_decadal_CRU_Historical_annual_1930-1939.tif represents the decade spanning 1930-1939. The data were generated by using the Hamon equation and output from a statistically downscaled version of the Hadley Centre’s CRU TS3.0 observational dataset. Data are at 2km x 2km resolution, and all data are stored in geotiffs. Calculations were performed using R 2.12.1 and 2.12.2 for Mac OS Leopard, and data were formatted into geotiffs using the raster and rgdal packages. Users are reminded that the PET estimates...
Potential Evapotranspiration (PET): These data represent decadal mean totals of potential evapotranspiration estimates (mm). The file name specifies the decade the raster represents. For example, a file named pet_mean_mm_decadal_CRU_Historical_annual_1930-1939.tif represents the decade spanning 1930-1939. The data were generated by using the Hamon equation and output from a statistically downscaled version of the Hadley Centre’s CRU TS3.0 observational dataset. Data are at 2km x 2km resolution, and all data are stored in geotiffs. Calculations were performed using R 2.12.1 and 2.12.2 for Mac OS Leopard, and data were formatted into geotiffs using the raster and rgdal packages. Users are reminded that the PET estimates...
These rasters represent estimated potential evapotranspiration (mm). Data were generated by using the Hamon equation and historical air temperature projections from the CRU dataset.
Fire can be a significant driver of permafrost change in boreal landscapes, altering the availability of soil carbon and nutrients that have important implications for future climate and ecological succession. However, not all landscapes are equally susceptible to fire-induced change. As fire frequency is expected to increase in the high latitudes, methods to understand the vulnerability and resilience of different landscapes to permafrost degradation are needed. Geophysical and other field observations reveal details of both near-surface (less than 1 m) and deeper (greater than 1 m) impacts of fire on permafrost along 14 transects that span burned-unburned boundaries in different landscape settings within interior...
Categories: Data;
Types: Citation,
Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Active layer thickness,
Alaska,
Borehole nuclear magnetic resonance,
Chatanika,
City of Fairbanks,
This derivative engineering-geologic map illustrates potential near-surface sources of various geologic materials that may be useful for construction near the Dalton Highway area, from Atigun Gorge to Slope Mountain. The map area is located in the west-central Philip Smith Mountains quadrangle. The map extends from the northern flank of the Endicott Mountains into the Arctic Foothills province. Field observations indicate that each geologic unit (for example, stream alluvium) has a definite composition or range of composition. Therefore, the probable presence of materials is interpreted from the distribution of geologic units on the geologic map of this quadrangle. Map unit descriptions also include discussion of...
During 2006 and 2007 the Alaska Division of Geological & Geophysical Surveys conducted reconnaissance surficial-geologic mapping in segment 1 of the Alaska Highway corridor, which straddles the Alaska Highway through the Tanana River valley from Delta Junction to the eastern boundary of the Mt. Hayes Quadrangle. Surficial-geologic deposits were initially mapped by interpreting ~1:63,360-scale, false-color infrared aerial photographs taken in August 1980 and field verified in 2006-2007.
The engineering-geologic map, on two sheets, is derived electronically from the surficial-geologic map of the initial segment of the proposed natural gas pipeline corridor through the upper Tanana valley (Reger and others, PIR 2008-3a) using Geographic Information System (GIS) software. Surficial-geologic units were initially identified by interpretation of false-color ~1:63,000-scale infrared aerial photographs taken in July 1978, August 1980, and August 1981 and locally verified by field checking in 2006 and 2007. The map shows the distribution of surficial-geologic and bedrock units grouped genetically with common properties that are typically significant for engineering applications.
During 2008 the Alaska Division of Geological & Geophysical Surveys (DGGS) conducted reconnaissance interpretive mapping of permafrost in Alaska Highway Corridor Segment 2, a 12-mi-wide (19.3-km-wide) corridor that straddles the Alaska Highway through the upper Tanana River valley from the eastern boundary of the Mt. Hayes Quadrangle to the eastern edge of the Tanacross Quadrangle. This work was an extension of permafrost mapping done in Alaska Highway Corridor Segment 1 from Delta Junction to Dot Lake in the Big Delta and Mt. Hayes Quadrangles during 2006-2007. Primarily, we inferred the extent of permafrost and ice content by interpreting ~1:65,000-scale, false-color infrared aerial photographs taken in July 1978,...
Abstract (from http://www.ncbi.nlm.nih.gov/pubmed/26463267): Lowland boreal forest ecosystems in Alaska are dominated by wetlands comprised of a complex mosaic of fens, collapse-scar bogs, low shrub/scrub, and forests growing on elevated ice-rich permafrost soils. Thermokarst has affected the lowlands of the Tanana Flats in central Alaska for centuries, as thawing permafrost collapses forests that transition to wetlands. Located within the discontinuous permafrost zone, this region has significantly warmed over the past half-century, and much of these carbon-rich permafrost soils are now within ~0.5 °C of thawing. Increased permafrost thaw in lowland boreal forests in response to warming may have consequences for...
Categories: Publication;
Types: Citation;
Tags: Alaska CASC,
Data Visualization & Tools,
Science Tools for Managers,
boreal,
permafrost,
Geophysical measurements and related field data were collected by the U.S. Geological Survey (USGS) at the Alaska Peatland Experiment (APEX) site in Interior Alaska from 2018 to 2020 to characterize subsurface thermal and hydrologic conditions along a permafrost thaw gradient. The APEX site is managed by the Bonanza Creek LTER (Long Term Ecological Research). Nine instrument monitoring sites (APEX1-APEX9) were established in April 2018. To quantify permafrost and thaw zone characteristics along the instrumented gradient, electrical resistivity tomography (ERT) data were collected in August 2018 along four 82 meter (m)-long transects between select sites: APEX1-3, APEX5-3, APEX5-7, and APEX6-8. Data were collected...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Active layer thickness,
Alaska,
Bonanza Creek,
Disturbance,
Electrical resistivity tomography,
The distribution of permafrost in cold regions is subject to temporal and spatial changes influenced by climate, landscape disturbance, and ecosystem succession. Remote sensing from airborne and satellite platforms is increasing our understanding of landscape-scale permafrost distribution, but typically lacks the resolution to characterize finer-scale processes and phenomena, which are often better captured by surface geophysical methods. Specifically, the electrical conductivity of the earth can be used to infer lithological and pore fluid properties, and in this case to delineate frozen, partially frozen, and unfrozen ground. Here, we present electromagnetic induction (EMI) data collected in August 2012 around...
Fire can be a significant driver of permafrost change in boreal landscapes, altering the availability of soil carbon and nutrients that have important implications for future climate and ecological succession. However, not all landscapes are equally susceptible to fire-induced change. As fire frequency is expected to increase in the high latitudes, methods to understand the vulnerability and resilience of different landscapes to permafrost degradation are needed. Geophysical and other field observations reveal details of both near-surface (<1 m) and deeper (>1 m) impacts of fire on permafrost along 11 transects that span burned-unburned boundaries in different landscape settings within interior Alaska. Data collected...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Alaska,
City of Fairbanks,
Disturbance,
Fire,
Permafrost,
The National Crude Oil Spill Fate and Natural Attenuation Research Site is located near Bemidji, MN, USA. A high-pressure oil pipeline ruptured in 1979 releasing ~1.7 million liters of light crude oil, which sprayed over an area of ~6500 square meters and collected in topographic depressions. Approximately 75% of the spilled oil was recovered. Much of the remainder reached the water table, where it is distributed into three residual oil bodies (the north, middle, and south oil pools). Groundwater flows east-northeast toward a small lake roughly 300 m downgradient from the original spill site. Secondary reactions of sediments with byproducts from anaerobic degradation of the oil plumes cause increases in total dissolved...
Categories: Data Release - Revised;
Tags: Ambient Monitoring,
Bemidji,
Focused Assessments,
Geophysics,
Geophysics,
The datasets contained herein include permafrost microbial community taxanomic and functional information using metagenomics from 133 samples across the panarctic. Datasets also include soil edaphic and location data.
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: USGS Science Data Catalog (SDC),
arctic,
biota,
functional traits,
metagenomics,
Geophysical measurements were collected by the U.S. Geological Survey (USGS) at five sites in Interior Alaska in September 2021 for the purposes of imaging permafrost structure and quantifying variations in subsurface moisture content in relation to thaw features. Electrical resistivity tomography (ERT) measurements were made along transects 110-222 meters (m) in length to quantify subsurface permafrost characteristics. ERT transects were collected across a fireline boundary within the Bonanza Creek Long Term Ecological Research (LTER) site where repeat measurements have been made since 2014; across and adjacent to two thermokarst lakes, Vault Lake and Goldstream Lake; and along two profiles at the North Star golf...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: "Climatology"],
Active layer thickness,
Alaska,
Bonanza Creek,
Borehole nuclear magnetic resonance,
Categories: Publication;
Types: Citation;
Tags: active layer,
cold regions hydrology,
frozen soil,
ground thaw,
hydrological modelling,
A high spatial resolution storm surge model was developed for the YK Delta area to assess biological impacts of storm surges under current and future climates. Storm surges are expected to be more frequent and more severe in the YK Delta area due to climate change and sea level rise. The biological impacts in the YK Delta due to the changed storm surges could be extreme.The model was assessed with respect to measured water level data at the coast and, where available, spatial extent of inundation, for 6 storms from the period 1992 to 2011. In total, inundation projections from 9 historical storms (5 from the assessment + 4 others) were developed. For each storm, an spatial inundation index (time-integral of water...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: ARCHAEOLOGICAL AREAS,
ARCHAEOLOGICAL AREAS,
Academics & scientific researchers,
COASTAL AREAS,
COASTAL AREAS,
This project resulted in an extensive mapping of coastal change along the entire coastline of the Western Alaska Landscape Conservation Cooperative (LCC). The work provides important baseline information on the distribution and magnitude of landscape changes over the past 41 years. The extent of change to the coastline and to coastal features, such as spits, barrier islands, estuaries, tidal guts and lagoons, was known to be substantial in some areas along the coast (e.g., portions of the Yukon–Kuskokwim Delta), although the extent of change along the full Bering Sea coast was not well documented. With this analysis, changes can be summarized for different land ownerships or other units to assess the extent of recent...
Categories: Data;
Tags: BARRIER ISLANDS,
BARRIER ISLANDS,
BARRIER ISLANDS,
BARRIER ISLANDS,
COASTAL AREAS,
The Fish Creek Watershed encompasses diverse aquatic habitats representative of much of the Arctic Coastal Plain of northern Alaska. Beyond surface water and permafrost responses caused by changes in climate, this landscape is also subject to potential land-use impacts related to petroleum development in the National Petroleum Reserve – Alaska (NPR-A). Thus, this region is an ideal setting to address aquatic habitat questions of longstanding interest to Arctic resource managers, scientists, and other stakeholders. Our multidisciplinary team is focusing on broad hypothesis that surface-water availability, connectivity, and temperature mediate aquatic habitats and trophic dynamics. We are working to understand and...
These data are the result of a geospatial analysis involving multi-year SAR-based lake ice regime classification using sigma-naught backscatter intensity from calibrated space-borne C-band SAR for thousands of lakes in 7 lake districts in Alaska, USA, detailed in Engram et al., (in review). Historically, radar backscatter from space-borne and airborne platforms shows a lower backscatter return from bedfast lake ice and a higher backscatter return from floating ice (where liquid phase water exists under the ice) (Jeffries, Morris, Weeks, & Wakabayashi, 1994; Weeks, 1977). We used a threshold method where the threshold to differentiate floating and bedfast ice regimes was determined for each year from the frequency...
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