These data comprise 505 unique geospatial raster datasets which describe persistent river ice (aufeis) occurrence within floodplains of select rivers and creeks in the 1002 Area of the Arctic National Wildlife Refuge in northern Alaska. Each raster is derived from a historical observation made by one of five Landsat satellites. Surface reflectance in the green and shortwave infrared wavelengths are used to classify the aufeis occurrence within individual pixels. Pixel values of "1" correspond to aufeis presence while "0" corresponds to its absence. Rasters are generated from cloud and snow-filtered images captured between May and September for the years 1985-2022.

This data package includes 17,014 pairs of raster geotiffs. Each pair is made up of two geotiff rasters derived from historical observations from Landsat satellites (04-09) over the Yukon, Kuskokwim, and Tanana rivers in Alaska. One raster reports estimated mid-day water surface temperature (ST) in degrees Celsius (deg_Cc). The second raster reports the surface temperature quality assessment (sST_QA_c) and provides the ST product uncertainty (also in degrees). The period of observation is May through October for the years 1984-2022.

This data package includes 17,014 pairs of raster geotiffs. Each pair is made up of two geotiff rasters derived from historical observations from Landsat satellites (04-09) over the Yukon, Kuskokwim, and Tanana rivers in Alaska. One raster reports estimated mid-day water surface temperature (ST) in degrees Celsius (deg_Cc). The second raster reports the surface temperature quality assessment (sST_QA_c) and provides the ST product uncertainty (also in degrees). The period of observation is May through October for the years 1984-2022.

These data include water chemistry from springs, streams, rivers, and shallow groundwater collected in the Arctic National Wildlife Refuge in northern Alaska. Chemical analyses were performed for hydrochemical parameters including field parameters, major ions, nutrients, metals, stable isotopes of water, and tritium, as well as for dissolved gases useful for determining the timescale over which the water was in the subsurface (i.e. age dating tracers), including noble gases and chlorofluorocarbons.

During the 2006 field season, the Alaska Division of Geological & Geophysical Surveys conducted remote mapping as part of the Kavik River STATEMAP project.This surficial-geologic mapping was conducted to provide additional detail to the STATEMAP comprehensive geologic mapping as well as to serve as a stand-alone map publication.

This data release documents the data used for the associated publication "Evaluating hydrologic region assignment techniques for ungaged watersheds in Alaska, USA" (Barnhart and others, 2022) The data sets within this release are stored in 14 files: (1) Streamflow observations and sites used. (2) Statistically estimated streamflow values computed for each site. (3) Streamflow statistics computed from observed and estimated streamflow values at each site, basin characteristics for each site, and hydrologic regions (clusters) for each site. (4) A dataset describing the optimal number of hydrologic regions into which the considered sites were grouped. (5) P-values from a multiple comparisons analysis testing for statistical differences between clusters for each basin characteristic and streamflow statistic. (6) A matrix of zeros and ones describing the performance of each hydrologic region assignment technique considered in the publication associated with this release. (7) A dataset of variable importance generated by random forest modeling-based hydrologic region assignment techniques evaluated. (8-14) Daily datasets of simulated SnowModel (Liston and Elder, 2006) runoff (snowmelt + rainfall), precipitation, glacial melt, snow water equivalent, snow covered area, liquid precipitation, and air temperature for Alaska, USA at a 1 km grid cell size.

This data release documents the data used for the associated publication "Evaluating hydrologic region assignment techniques for ungaged watersheds in Alaska, USA" (Barnhart and others, 2022) The data sets within this release are stored in 14 files: (1) Streamflow observations and sites used. (2) Statistically estimated streamflow values computed for each site. (3) Streamflow statistics computed from observed and estimated streamflow values at each site, basin characteristics for each site, and hydrologic regions (clusters) for each site. (4) A dataset describing the optimal number of hydrologic regions into which the considered sites were grouped. (5) P-values from a multiple comparisons analysis testing for statistical differences between clusters for each basin characteristic and streamflow statistic. (6) A matrix of zeros and ones describing the performance of each hydrologic region assignment technique considered in the publication associated with this release. (7) A dataset of variable importance generated by random forest modeling-based hydrologic region assignment techniques evaluated. (8-14) Daily datasets of simulated SnowModel (Liston and Elder, 2006) runoff (snowmelt + rainfall), precipitation, glacial melt, snow water equivalent, snow covered area, liquid precipitation, and air temperature for Alaska, USA at a 1 km grid cell size.

Alaska Division of Geological & Geophysical Surveys (DGGS) has conducted 1:63,360-scale geologic mapping of the Sagavanirktok B-1 Quadrangle (640 square km�equivalent to four 7.5 minute quadrangles). This mapping project reinterprets micropaleontologic correlations for 17 Sagavanirktok Quadrangle wells, and reprocesses data from the one publicly-available seismic line. Surface geologic mapping, subsurface-to-surface stratigraphic age control, and seismic framework are required to reliably decipher the complex geology of this key area of the Brooks Range. Outcrops within the Sagavanirktok B-1 Quadrangle are the closest surface expressions of Prudhoe Bay source and reservoir rocks. This study yields critical petroleum-related information from these surface exposures, and how they relate to the area subsurface stratigraphy.

This dataset represents a digitized version of the Rawlinson 1993 surficial geologic map of the Flaxman Island and Beechy Point quadrangles, and portions of the Mount Michelson and Harrison Bay quadrangles at 1:63,360 scale. In this newly digitized version of the map, the original maps were scanned, georeferenced, and projected into GIS. Approximately 100-200 typographic and labelling errors from the paper version were corrected with inputs from the original author (corrections completed in 2024). However, this digitized product still adheres to the 1993 interpretation of the surficial geology. Original descriptions of the map units can be found with the 1993 publication (https://doi.org/10.14509/2484). The original 1993 map was generated via photointerpretation done manually on acetate sheets overlain on color infrared aerial photographs, aided by a stereoscope, and then manually transferred to a map base using a zoom-transfer scope. Only low-resolution 1:250,000-scale black-and-white Landsat imagery was available for reference in the 1980s when the mapping was completed. After photointerpretation, the surficial geology units and morphology information was field spot-checked, with extensive fieldwork occurring between 1981 and 1985. As part of the fieldwork, locations with exposure along coasts, rivers, and gravel pits were prioritized, with 464 stratigraphic sections measured and described, and 678 samples collected for analyses that included grain size, radiocarbon and thermoluminescence dating, amino acid analysis in mollusk shells and wood, identification of wood types, and microfossil and pollen contents. An important note of caution to users is that this digitized product represents the 1993 interpretation of surficial geology. Modifications to the 1993 product address typographic errors and do not consider re-interpretations of the surficial geological units since then, and more recent information about the regional surficial geology is available.

The U.S. Geological Survey in collaboration with the U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory (CRREL) collected topographic LiDAR surveys of six rivers in Alaska from August 27- September 1, 2018 to support research related to remote sensing of river discharge. Data were acquired for the Knik, Matanuska, Chena, Salcha, Tanana and Snow Rivers using a Riegl VQ-480 LiDAR. The LiDAR was installed on a Robinson R44 Raven helicopter in a HeliPod that was designed and operated by CRREL. The LiDAR data included as part of this release include: a bare earth digital elevation model (DEM) and compressed binary LAS point cloud files (LAZ format) for each river surveyed.