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At least 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

The age and potential causes of the giant Green Lake Landslide, Fiordland, New Zealand

Abstract Landslide deposits preserved in the geological record afford opportunities to better inform hillslope and seismic hazard and risk models, particularly in regions where observational records are short. In the Southern Alps of New Zealand, small coseismic landslides are frequent, but the geological record preserves several instances of more substantial (> 1 km 3 ) but infrequent mass failures. With an estimated volume of 27 km 3 , the giant Green Lake Landslide represents one of the largest subaerial landslides on Earth. Previous work has suggested this deep-seated mass movement was most likely triggered by high-intensity seismic shaking, but that local structural weakness and/or glacial debuttressing may help to explain the anomalously large failure volume. Resolving the potential contribution of the latter is important given predictions concerning alpine deglaciation in the coming decades to centuries. Key to resolution are secure chronologies of landslide emplacement and past glacier change. Here we present in situ cosmogenic 10 Be exposure ages from the Green Lake Landslide that suggest an emplacement age of 15.5 ± 0.7 ka. Recent work shows that glacial retreat in the region was underway by 19 ka, indicating that the Green Lake Landslide was emplaced 3–4 kyr after the onset of glacier retreat. Given the geometry of the former confining valley glacier, we expect that the deglaciation-landslide age gap is closer to the upper end of this estimate. If correct, this conclusion places greater weight on the roles of local geological structure and/or a great earthquake as factors contributing to the exceptionally large volume of this event.

58 GEOSCIENCES↗
DOE OSTI2023

Urban Versus Lake Impacts on Heat Stress and Its Disparities in a Shoreline City

Abstract Shoreline cities are influenced by both urban‐scale processes and land‐water interactions, with consequences on heat exposure and its disparities. Heat exposure studies over these cities have focused on air and skin temperature, even though moisture advection from water bodies can also modulate heat stress. Here, using an ensemble of model simulations covering Chicago, we find that Lake Michigan strongly reduces heat exposure (2.75°C reduction in maximum average air temperature in Chicago) and heat stress (maximum average wet bulb globe temperature reduced by 0.86°C) during the day, while urbanization enhances them at night (2.75 and 1.57°C increases in minimum average air and wet bulb globe temperature, respectively). We also demonstrate that urban and lake impacts on temperature (particularly skin temperature), including their extremes, and lake‐to‐land gradients, are stronger than the corresponding impacts on heat stress, partly due to humidity‐related feedback. Likewise, environmental disparities across community areas in Chicago seen for skin temperature are much higher (1.29°C increase for maximum average values per $10,000 higher median income per capita) than disparities in air temperature (0.50°C increase) and wet bulb globe temperature (0.23°C increase). The results call for consistent use of physiologically relevant heat exposure metrics to accurately capture the public health implications of urbanization.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Substantial and overlooked greenhouse gas emissions from deep Arctic lake sediment

Thermokarst lakes cause abrupt and sustained permafrost degradation and have the potential to release large quantities of ancient carbon to the atmosphere. Despite concerns about how lakes will affect the permafrost carbon feedback, the magnitude of carbon dioxide and methane emissions from deep permafrost soils remains poorly understood. Here we incubated a very deep sediment core (20 m) to constrain the potential productivity of thawed Yedoma and underlying Quaternary sand and gravel deposits. Through radiocarbon dating, sediment incubations and sediment facies classifications, we show that extensive permafrost thaw can occur beneath lakes on timescales of decades to centuries. Although it has been assumed that shallow, aerobic carbon dioxide production will dominate the climate impact of permafrost thaw, we found that anaerobic carbon dioxide and methane production from deep sediments was commensurate with aerobic production on a per gram carbon basis, and had double the global warming potential at warmer temperatures. Carbon release from deep Arctic sediments may thus have a more substantial impact on a changing climate than currently anticipated. These environments are presently overlooked in estimates of the permafrost carbon feedback.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

Coassembly and binning of a twenty-year metagenomic time-series from Lake Mendota

Abstract The North Temperate Lakes Long-Term Ecological Research (NTL-LTER) program has been extensively used to improve understanding of how aquatic ecosystems respond to environmental stressors, climate fluctuations, and human activities. Here, we report on the metagenomes of samples collected between 2000 and 2019 from Lake Mendota, a freshwater eutrophic lake within the NTL-LTER site. We utilized the distributed metagenome assembler MetaHipMer to coassemble over 10 terabases (Tbp) of data from 471 individual Illumina-sequenced metagenomes. A total of 95,523,664 contigs were assembled and binned to generate 1,894 non-redundant metagenome-assembled genomes (MAGs) with ≥50% completeness and ≤10% contamination. Phylogenomic analysis revealed that the MAGs were nearly exclusively bacterial, dominated by Pseudomonadota (Proteobacteria, N = 623) and Bacteroidota (N = 321). Nine eukaryotic MAGs were identified by eukCC with six assigned to the phylum Chlorophyta. Additionally, 6,350 high-quality viral sequences were identified by geNomad with the majority classified in the phylum Uroviricota. This expansive coassembled metagenomic dataset provides an unprecedented foundation to advance understanding of microbial communities in freshwater ecosystems and explore temporal ecosystem dynamics.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2024

Optimization of floodwater redistribution from Lake Nasser could recharge Egypt’s aquifers and mitigate its excessive floods

Extreme precipitation periods, possibly related to climate change, over the Nile River source areas caused flooding in Sudan and excess runoff reaching Lake Nasser in Egypt in 1998–2002 and 2019–2022. Excess water from the 1st event (25.5 × 10 9 m 3 ) was channeled to depressions within the plateau west of the Nile Valley, forming the Tushka Lakes, where it was left to evaporate, a fate that awaits the 53.5 × 10 9 m 3 from the 2nd event while the underlying fossil Nubian Sandstone Aquifer System is being depleted (–0.98 × 10 9 m 3 /yr). We simulated release scenarios of excess Lake Nasser waters (53.5 × 10 9 m 3 ) to proximal lowlands; preference was given to the scenario that recharged the aquifer through infiltration (74.3%) and minimized losses to evaporation (20.1%) and surface runoff (5.6%). Findings serve as an example of adaptations that replace catastrophic consequences of climate change with beneficial and sustainable development opportunities.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

AmeriFlux US-Act Acton Lake Flux Tower Site

This is the AmeriFlux version of the carbon flux data for the site US-Act Acton Lake Flux Tower Site. Site Description - This tower is located at Acton Lake, a eutrophic reservoir immediately surrounded by forest but draining an agricultural watershed in Hueston Woods State Park outside of Oxford, OH. The EC instrumentation was originally deployed 25 m from shore on a dock piling. In April of 2018 a lake tower was installed >200 m from the closest shoreline. The EC instrumentation was deployed on this aquatic tower on 7 May 2018.

Waldo, Sarah↗
DOE OSTI2023

AmeriFlux FLUXNET-1F US-xDL NEON Dead Lake (DELA)

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-xDL NEON Dead Lake (DELA). This is the FLUXNET version of the carbon flux data for the site US-xDL NEON Dead Lake (DELA) produced by applying the standard ONEFlux (1F) software. Site Description - The Dead Lake site is just northeast of Demopolis, AL near the Black Warrior River. The site is in Major Land Resource Area (MLRA) 133A–Southern Coastal Plains, near the boundary of MLRA 135A–Alabama and Mississippi Blackland Prairie. Surrounded by woody wetlands and evergreen forest, DELA sits on the flood plain steps and stream terraces of an inside meander of the Black Warrior River in Greene Co., AL.

Network), NEON (National Ecological Observatory↗
DOE OSTI2023

AmeriFlux FLUXNET-1F US-xML NEON Mountain Lake Biological Station (MLBS)

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-xML NEON Mountain Lake Biological Station (MLBS). This is the FLUXNET version of the carbon flux data for the site US-xML NEON Mountain Lake Biological Station (MLBS) produced by applying the standard ONEFlux (1F) software. Site Description - Mountain Lake Biological Station (MLBS) is a remote, but accessible research station and is a unit of the College of Arts & Sciences at University of Virginia. It sits at 1160 meters on the top of Salt Pond Mountain in the southern Appalachian mountains in southwestern Virginia. It consists of 259 hectares of forested reserve.

Network), NEON (National Ecological Observatory↗
DOE OSTI2023

AmeriFlux FLUXNET-1F US-Pnp Lake Mendota, Picnic Point Site

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-Pnp Lake Mendota, Picnic Point Site. This is the FLUXNET version of the carbon flux data for the site US-Pnp Lake Mendota, Picnic Point Site produced by applying the standard ONEFlux (1F) software. Site Description - The site is located on the shoreline of Lake Mendota on the rooftop of UW-Madison's Center for Limnology.

Desai, Ankur↗
DOE OSTI2025

AmeriFlux FLUXNET-1F US-PFe NW4 Lake-1 CHEESEHEAD 2019

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-PFe NW4 Lake-1 CHEESEHEAD 2019. This is the FLUXNET version of the carbon flux data for the site US-PFe NW4 Lake-1 CHEESEHEAD 2019 produced by applying the standard ONEFlux (1F) software. Site Description - This tower (32m, trailer-based, telescoping) is located in the northwestern quadrant of the 10 x 10km study domain. It is located in a red pine and aspen forest (20.1 m height) on the bank of a lake (500m across).

Desai, Ankur [University of Wisconsin-Madison]↗
DOE OSTI2025

AmeriFlux FLUXNET-1F US-UTP UFLUX Great Salt Lake Phragmites

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-UTP UFLUX Great Salt Lake Phragmites. This is the FLUXNET version of the carbon flux data for the site US-UTP UFLUX Great Salt Lake Phragmites produced by applying the standard ONEFlux (1F) software. Site Description - The station is in the middle of a stand of invasive Phragmites australis, located on the margin of the Great Salt Lake in Farmington Bay.

Inkenbrandt, Paul [Utah Geological Survey]↗
DOE OSTI2026

AmeriFlux FLUXNET-1F US-RC5 Moses Lake on-farm site

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-RC5 Moses Lake on-farm site. This is the FLUXNET version of the carbon flux data for the site US-RC5 Moses Lake on-farm site produced by applying the standard ONEFlux (1F) software. Site Description - The Moses Lake On-farm site operated 2013-2015 as part of a cluster of 5 towers (RC1 to RC5) operated for the Regional Approaches to Climate Change (REACCH) USDA-supported research project. The field was a half-circle irrigated plot with the irrigation pivot located on the edge of the field and the flux tower located next to the center of the pivot. The field was in wheat from tower establishment in June 2013 to harvest in August 2013. A cover crop of arugula and mustard was grown from August to October 2013. Potatoes were grown April to August 2014 and wheat (a spring cultivar planted in fall) was grown October 2014 to June 2015. Soils are coarse sandy loam mollisols in the Timmerman series. The site topography is flat.

Chi, Jinshu [The Hong Kong University of Science a↗
DOE OSTI2026

AmeriFlux FLUXNET-1F US-MBP Marcell Bog Lake Peatland

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-MBP Marcell Bog Lake Peatland. This is the FLUXNET version of the carbon flux data for the site US-MBP Marcell Bog Lake Peatland produced by applying the standard ONEFlux (1F) software. Site Description - The study site is a fen within the Marcell Experimental Forest, which has been monitored for fluxes and environmental variables at various points in time. In 2007 an EC tower was established to monitor CO2/H2O fluxes within the peatland. Methane observations were added in 2009 and have been ongoing since. This site has also been referred to as Bog Lake Fen in the past.

Roman, Tyler [USDA Forest Service- International P↗
DOE OSTI2025

Expanding Collaborative Capacity to Address Climate Resiliency in the Great Lakes Region

U.S. Department of Energy (DOE), Office of Science, Award DE-SC0023215, Expanding Collaborative Capacity to Address Climate Resiliency in the Great Lakes Region, supported capacity and partnership building between researchers at Central Michigan University (CMU) and scientists at DOE laboratories. The work involved identifying potential collaborations both internal to CMU and between CMU researchers and DOE staff, developing collaborative research proposals, and partnering on pilot-scale research projects focused on enhancing resilience of Great Lakes communities, ecosystems, and infrastructure to global change and environmental stressors. DOE funds supported travel, time to develop collaborations, investigate new research pathways, and draft grant proposals, and a loan of DOE equipment to collect pilot data in support of future work. The project achieved its goal of strengthening research collaborations between interdisciplinary researchers at CMU and establishing new collaborations and partnerships between CMU and DOE scientists. These collaborations resulted in 5 pre-applications and 4 full applications for funding to DOE BER Funding Opportunities, a successfully funded DOE BER award (DE-SC0025260), a new pilot project that leveraged DOE resources (AquaBOT) to improve understanding of water quality conditions in Michigan rivers, and two presentations of preliminary results at national scientific conferences. This project’s outcomes will benefit the Great Lakes Region via new lines of collaborative research focused on improving the resilience of Michigan communities, ecosystems, and infrastructure.

58 GEOSCIENCES↗
DOE OSTI2024

Uncertainty characterization in a coupled human-natural system: Modeling agricultural adaptation in the Great Lakes Region

The Great Lakes Region's water quality and ecological health are threatened by the export of nutrients from agricultural lands, which causes eutrophication, hypoxia, and destructive algal blooms. The intensification of hydrologic cycles brought about by climate change is expected to exacerbate nutrient loading in the region, and, at the same time, agricultural adaptation to changing conditions is also expected to affect loading through shifting amounts and timing of fertilization. Quantifying these future effects and their interactions necessitates modeling both the human and natural processes as a coupled system, by pairing land use and agricultural management with hydrologic modeling. At the same time, compounding uncertainties arising from the complex interactions in both systems significantly limit our predictive understanding of the region's impacts. This study utilizes the Soil and Water Assessment Tool (SWAT), developed for simulating the impact of various farmer decisions on watershed functions in Western Lake Erie watersheds, and an under-development agent-based model (ABM) for agricultural management decisions. The aim of this study is to use global sensitivity analysis on the coupled ABM and SWAT models to quantify how uncertainty in both models interactively affects nutrient loading. To do so, we will conduct Sobol sensitivity analysis experiments at different levels of coupling assumptions to quantify how various uncertain factors (e.g., soil moisture and crop choice) and their interactions affect our estimates of nutrient loading. The results of this analysis will allow us to quantify how complex interactions and dependencies between both systems amplify the effect of uncertainties. Insights gained from this study will have broader implications for modeling the adaptive co-evolution of human and natural systems under climate change and can inform effective management of nutrient loading in the Great Lakes Region.

Climate Change↗
NASA NTRS1971

Analytical solution for the wind-driven circulation in a lake containing an island

An analysis was carried out to determine analytically the effect of an island on the wind driven currents in a shallow lake (or sea). A general analysis is developed that can be applied to a large class of lake and island geometries and bottom topographies. Detailed numerical results are obtained for a circular island located eccentrically or concentrically in a circular lake with a logarithmic bottom topography. It is shown that an island can produce volume flow (vertically integrated velocities) gyres that are completely different from those produced by a normal basin without an island. These gyres in the neighborhood of the island will produce different velocity patterns, which include the acceleration of flow near the island shore.

Goldstein, M. E.↗
NASA NTRS1972

Effect of eddy diffusivity on wind-driven currents in a two-layer stratified lake

The steady state wind-driven circulation was numerically calculated in a rectangular stratified lake. The lake is composed of two layers having uniform but unequal densities and eddy diffusivities. The position in thermocline and the three-dimensional velocities in both layers calculated using shallow lake equations. The results show that, as the eddy diffusivity in the hypolimnion is increased, the thermocline tilt and hypolimnetic velocities increase. The effect of the other variables such as wind stress, density, basin length, and mean thermocline depth are also shown.

Gedney, R. T.↗
NASA NTRS1972

ERTS-1 imagery of the Lake Champlain region: A first look

The author has identified the following significant results. First-look analysis of RBV imagery of Lake Champlain and adjacent areas provided the following information on land and water resources: (1) location and shape of islands over 200 meters at narrowest part; (2) location of manmade structures at least 10 meters across; (3) location of shoreline; (4) identification of algal blooms and major turbidity boundary; (5) identification of lake bottom features in sandy, shallow areas; (6) identification of major lake shore wetland and floodplain wetlands; (7) location of major streams; (8) identification of ice marginal deposits of major proportions and former shorelines of Champlain Sea; (9) identification of wooded areas, open land, and built-up areas.

Lind, A. O.↗