Filters: Contacts: Joshua C Koch (X)
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This dataset contains taxonomic information, counts, and lengths of macroinvertebrates collected from rivers in northwest Alaska using drift and kick nets during summer and fall 2015-2019. Version History: First release: February 2024 Revised: August 2024 (ver. 1.1)
Categories: Data,
Data Release - Revised;
Tags: Actinopterygii,
Age composition,
Alaska,
Animals/Invertebrates,
Animals/Invertebrates,
Permafrost (perennially frozen) and active-layer (seasonally thawed) soils varying in soil carbon (C) and nitrogen (N) content and radiocarbon age were collected from three sites in interior Alaska to determine potential release of dissolved organic carbon (DOC), total dissolved N (TDN), dissolved organic nitrogen (DON), and dissolved inorganic nitrogen (DIN) upon thaw. Soil cores were cut into 15 cm thick sections, and deep active-layer (15-30 cm above the permafrost boundary) and shallow permafrost (15-30 cm below the permafrost boundary) sections were thawed and leached with deionized water. Soil leachates were analyzed for DOC, TDN, nitrate (NO3-), and ammonium (NH4+) concentrations, dissolved organic matter...
Categories: Data;
Tags: Alaska,
Ecology,
Soil Sciences,
USGS Science Data Catalog (SDC),
Water Quality,
This data release contains measurements from continuous monitors of stream temperature, groundwater temperature, and well water levels, and discrete measurements of discharge and stream shading.
Categories: Data;
Tags: Alaska,
Climate change,
Environment,
Freshwater ecosystems,
GeoScientificInformation,
High latitude, boreal watersheds are nitrogen-limited ecosystems that export large amounts of organic carbon. Key controls on carbon cycling in these environments are the biogeochemical processes affecting the nitrogen cycle. This data release presents results of a 3-year field study from 2008-2011 to document the relation between seasonal and transport-associated changes in carbon and nitrogen pools within Nome Creek, an upland headwater tributary of the Yukon River, Alaska, and two first order tributaries to Nome Creek, West Twin Creek and East Twin Creek. Stream-water geochemistry was characterized using: a) biweekly sampling at fixed sampling stations to assess changes through the course of a summer season;...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Alaska,
Alaska,
USGS Science Data Catalog (SDC),
biota
This dataset includes discrete water quality and discharge data for three streams that flow through wetlands. There are two measurement and sampling locations on each stream: one immediately upstream from the wetland and one immediately downstream from the wetland. Measurements and sample collection occurred in 2010 and 2011 at West Twin Creek, AK; in 2019 and 2020 at Allequash Creek, WI; and in 2013, 2014, and 2017 at the Big Thompson River, CO. The upstream and downstream data from Allequash Creek and the Big Thompson River are from established USGS sites. At Allequash Creek, the downstream site is USGS 05357206 Allequash Creek Site No. 3 Nr Boulder Junction, WI, and the upstream site is USGS 5357205 Allequash...
Salmon are an important resource to the ecosystems, economy, and culture of the Kenai Peninsula, Alaska. However, salmon are under increasing stress due to warming water temperatures and decreasing stream flow. Groundwater is a major contributor to many streams that can help maintain fish habitat during low flows and contributes cooler water that regulates stream temperatures in the warm summer months. As the climate warms, the ability for groundwater to cool stream temperatures will likely become more critical to streams that are used by salmon, such as Beaver Creek near Kenai, Alaska. Preliminary analysis of historical streamflow data indicates that on average, Beaver Creek receives nearly 80% of its flow...
Categories: Project;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: 2022,
Alaska,
Alaska CASC,
CASC,
Other Water,
This data was produced as part of a subsurface tracer experiment performed on a boreal hillslope in July, 2015. The data is separated into three files: 'Well Data.csv' includes the location and depth of well screens, concentrations of the bromide tracer in time, saturation state of the subsurface at the wells, ground cover at the wells, and depth of the organic-mineral boundary which controls shallow flow. 'Probe data.csv' includes thaw depth, gravel presence, and vegetation type within the well field. 'Breakthroughs.csv' includes solute concentrations in time from wells that displayed robust breakthroughs. The data includes electrical conductivity and bromide measurements, and a column that combines these two solutes...
Abstract (from Wiley Online Library): Runoff from boreal hillslopes is often affected by distinct soil boundaries, including the frozen boundary and the organic-mineral boundary (OMB), where highly porous and hydraulically conductive organic material overlies fine-grained mineral soils. Viewed from the surface, ground cover appears as a patchwork on sub-meter scales, with thick, moss mats interspersed with lichen-covered, silty soils with gravel inclusions. We conducted a decameter-scale subsurface tracer test on a boreal forest hillslope in interior Alaska to quantify locations and mechanisms of transport and storage in these soils, focusing on the OMB. A sodium bromide tracer was added as a slug addition to a...
Categories: Publication;
Types: Citation;
Tags: Alaska CASC,
Rivers, Streams and Lakes,
Water, Coasts and Ice
This product consists of multiple tabular datasets and associated metadata of water quality information related to rivers, streams, and lakes in the Yukon River watershed between 2014 and 2018. This data release is apart of the National Aeronautics and Space Administration (NASA) funded Arctic-Boreal Vulnerability Experiment (ABoVE) and is an assessment of water quality and greenhouse gas fluxes within the interior of Alaska. Sampling frequency varied across locations, with some sites sampled twice a year or more. Data consist of: organic and inorganic carbon related species, carbon dioxide and methane gas fluxes calculated from manual chamber measurements, nitrogen species, carbon isotopes, oxygen and deuterium...
Categories: Data;
Types: Data,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Alaska,
Boot Lake,
CH4,
CO2,
CO2 Bubble Trap,
Permafrost – the thick layer of permanently frozen soil found in Arctic regions – has been thawing rapidly over the past century due to climate change. When permafrost thaws unevenly, it produces thermokarst landscapes, irregular surfaces of small hills interspersed with hollows. The processes that produce thermokarst can lead to significant changes within the surrounding ecosystems, altering water quality, vegetation, and water, carbon, and nutrient storage and flows. These changes can have substantial implications for fish and wildlife populations and disrupt rural communities and infrastructure. The goal of this project was to better understand the extent of thermokarst processes and the rate at which they...
Categories: Project;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: 2012,
Alaska,
Alaska CASC,
Arctic,
Arctic,
Areas along the Arctic coast are changing the fastest among all of Earth’s habitats due to climate change. The Arctic coast is a fragile ecosystem that provides habitat for migratory birds, endangered species, and species critical for local subsistence living. In this area, permafrost is thawing rapidly, changing how much and when water reaches rivers, ponds, lakes, wetlands and groundwater. In addition, there is also a growing interest in oil and gas resource exploration. With ongoing permafrost thaw, future warming, and interests in oil and gas extraction in the coastal plain (also known as the 1002 area) of the Arctic National Wildlife Refuge, it is urgent to improve the understanding of this area and its vulnerability...
Categories: Project;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: 2021,
Alaska,
Alaska,
Alaska CASC,
Alaska CASC,
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.
Categories: Data;
Tags: Aichilik River,
Alaska,
Arctic National Wildlife Refuge,
Canning River,
Dissolved gas,
This collection of hydrologic, biogeochemical, geophysical, soil, thermal, and physical data provides a framework for investigating the vulnerability of water and carbon cycles to changing permafrost conditions across boreal Alaska. Multidisciplinary data are needed to evaluate the effects of fire and climate on subsurface permafrost, soil physical, and hydrological conditions, which in turn are used to inform hydrological modeling of surface and subsurface water distribution, flow, and water availability in response to change. Vulnerability of the aquatic carbon cycle is investigated by detailed characterization of the chemistry, age, and degradability of permafrost carbon sources and their biogeochemical change,...
Frequency domain electromagnetic induction (FDEM) data were collected in September 2016 near the Agashashok River and its tributaries, within the Noatak National Preserve near Kotzebue, AK to aid in local permafrost mapping. Data were collected with a GEM-2 instrument (1.6 m coil separation, Geophex, Ltd.); a broadband sensor that measures the bulk conductivity and magnetic susceptibility of the subsurface to approximately 5-10 meters depth. The instrument is hand carried by a single operator and data are collected at walking speeds.
The Nome Creek Experimental Watershed (NCEW) has been the site of multiple studies focused on understanding hydrology, biogeochemistry, and ecosystem changes related to permafrost thaw and fire in the boreal forest. The boreal forest is the Earth’s largest terrestrial biome, and thus plays a major role in biogeochemical cycling, creation of habitat for wildlife, as well as wilderness and resources for humans. This project specifically investigates tracers experiments designed to provide comparative hydrological and soils investigations in a small, fire impacted, boreal forest watershed with discontinuous permafrost. The dataset includes field collected data on soil moisture, meteorology, stream flow, aquatic biogeochemistry,...
Categories: Project;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: 2014,
Alaska,
Alaska CASC,
CASC,
Completed,
This dataset includes tables related to macroinvertebrate collections in streams and springs of the 1002 region of the Arctic National Wildlife Refuge in northeastern Alaska. Macroinvertebrates were collected using kicknets and driftnets in April and August with the goal of comparing populations to those sampled from the same water bodies by the USGS in the 1970s.
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