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Environmental Sciences

2022

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Articles 61 - 70 of 70

Full-Text Articles in Other Earth Sciences

Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev Jan 2022

Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev

United States Geological Survey: Staff Publications

Predictive modeling of submerged archaeological sites requires accurate sea-level predictions in order to reconstruct coastal paleogeography and associated geographic features that may have influenced the locations of occupation sites such as rivers and embayments. Earlier reconstructions of the paleogeography of parts of the western U.S. coast used an assumption of eustatic sea level, but this neglects the large spatial variations in relative sea level (RSL) associated with glacial isostatic adjustment (GIA) and tectonics. Subsequent work using a one-dimensional (1-D) solid Earth model showed that reconstructions that accounted for GIA result in significant differences from those based on eustatic sea level. …


Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev Jan 2022

Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev

United States Geological Survey: Staff Publications

Predictive modeling of submerged archaeological sites requires accurate sea-level predictions in order to reconstruct coastal paleogeography and associated geographic features that may have influenced the locations of occupation sites such as rivers and embayments. Earlier reconstructions of the paleogeography of parts of the western U.S. coast used an assumption of eustatic sea level, but this neglects the large spatial variations in relative sea level (RSL) associated with glacial isostatic adjustment (GIA) and tectonics. Subsequent work using a one-dimensional (1-D) solid Earth model showed that reconstructions that accounted for GIA result in significant differences from those based on eustatic sea level. …


A Greenhouse Gas Emissions Inventory For Nebraska: Livestock And Coal Loom Large, Eric R. Holley, Adam Liska Jan 2022

A Greenhouse Gas Emissions Inventory For Nebraska: Livestock And Coal Loom Large, Eric R. Holley, Adam Liska

Adam Liska Papers

Mitigation of climate change requires the systematic identification and cataloging of emissions sources at city, state, and national levels. In this study, an inventory of annual greenhouse gas emissions from the state of Nebraska was created based on industry data, and emissions inventories were completed each year from 1990 to 2016. Nebraska’s net emissions were found to increase from 56.2 million metric tons of carbon dioxide equivalents (MMtCO2e) in 1990 to 87.4 MMtCO2e in 2016. Agriculture was found to be the sector with the most emissions (36 MMtCO2e) followed by electricity generation (21 MMtCO …


Fine Scale Mapping Of Laurentian Mixed Forest Natural Habitat Communities Using Multispectral Naip And Uav Datasets Combined With Machine Learning Methods, Parth P. Bhatt Jan 2022

Fine Scale Mapping Of Laurentian Mixed Forest Natural Habitat Communities Using Multispectral Naip And Uav Datasets Combined With Machine Learning Methods, Parth P. Bhatt

Dissertations, Master's Theses and Master's Reports

Natural habitat communities are an important element of any forest ecosystem. Mapping and monitoring Laurentian Mixed Forest natural communities using high spatial resolution imagery is vital for management and conservation purposes. This study developed integrated spatial, spectral and Machine Learning (ML) approaches for mapping complex vegetation communities. The study utilized ultra-high and high spatial resolution National Agriculture Imagery Program (NAIP) and Unmanned Aerial Vehicle (UAV) datasets, and Digital Elevation Model (DEM). Complex natural vegetation community habitats in the Laurentian Mixed Forest of the Upper Midwest. A detailed workflow is presented to effectively process UAV imageries in a dense forest environment …


Sea Surface Temperatures And Vertical Wind Shear As Precursors To Tropical Cyclone Activity In The Caribbean And An Expanding Main Developing Region, Keneshia Hibbert Jan 2022

Sea Surface Temperatures And Vertical Wind Shear As Precursors To Tropical Cyclone Activity In The Caribbean And An Expanding Main Developing Region, Keneshia Hibbert

Dissertations and Theses

Sea surface temperatures and vertical wind shear are essential to tropical cyclone formation. TCs need warm SSTs and low shear for genesis. Increasing SSTs and VWS changes influence storm development. This work analyzes SST and VWS trends for the Caribbean, surrounding region, and the Atlantic hurricane main developing region from 1982 to 2020. Storm intensity increases significantly during this period. Annual and seasonal trends show regional SSTs in the MDR are warming annually (0.0219°C yr-1) and per season (0.0280°C yr-1). Simultaneously, VWS decreases during the late rainfall season at 0.0556m/s yr-1 in the MDR and …


Data Fusion And Synergy Of Active And Passive Remote Sensing; An Application For Freeze Thaw Detections, Zahra Sharifnezhadazizi Jan 2022

Data Fusion And Synergy Of Active And Passive Remote Sensing; An Application For Freeze Thaw Detections, Zahra Sharifnezhadazizi

Dissertations and Theses

There has been a recent evolvement in the field of remote sensing after increase of number satellites and sensors data which could be fused to produce new data and products. These efforts are mainly focused on using of simultaneous observations from different platforms with different spatial and temporal resolutions. The research dissertation aims to enhance the synergy use of active and passive microwave observations and examine the results in detection land freeze and thaw (FT) predictions. Freeze thaw cycles particularly in high-latitude regions have a crucial role in many applications such as agriculture, biogeochemical transitions, hydrology and ecosystem studies. The …


Mis 5e Sea-Level History Along The Pacific Coast Of North America, Daniel R. Muhs Jan 2022

Mis 5e Sea-Level History Along The Pacific Coast Of North America, Daniel R. Muhs

United States Geological Survey: Staff Publications

The primary last interglacial, marine isotope substage (MIS) 5e records on the Pacific coast of North America, from Washington (USA) to Baja California Sur (Mexico), are found in the deposits of erosional marine terraces. Warmer coasts along the southern Golfo de California host both erosional marine terraces and constructional coral reef terraces. Because the northern part of the region is tectonically active, MIS 5e terrace elevations vary considerably, from a few meters above sea level to as much as 70m above sea level. The primary paleo-sea-level indicator is the shoreline angle, the junction of the wave-cut platform with the former …


Using Landsat-Based Phenology Metrics, Terrain Variables, And Machine Learning For Mapping And Probabilistic Prediction Of Forest Community Types In West Virginia, Faith M. Hartley Jan 2022

Using Landsat-Based Phenology Metrics, Terrain Variables, And Machine Learning For Mapping And Probabilistic Prediction Of Forest Community Types In West Virginia, Faith M. Hartley

Graduate Theses, Dissertations, and Problem Reports

This study investigates the mapping of forest community types for the entire state of West Virginia, USA using Global Land Analysis and Discovery (GLAD) Phenology Metrics analysis ready data (ARD) derived from the Landsat time series and digital terrain variables derived from a digital terrain model (DTM). Both classifications and probabilistic predictions were made using random forest (RF) machine learning (ML) and training data derived from ground plots provided by the West Virginia Natural Heritage Program (WVNHP). The primary goal of this study is to explore the use of globally consistent ARD data for operational forest type mapping over a …


The Burning Bush: Linking Lidar-Derived Shrub Architecture To Flammability, Michelle S. Bester Jan 2022

The Burning Bush: Linking Lidar-Derived Shrub Architecture To Flammability, Michelle S. Bester

Graduate Theses, Dissertations, and Problem Reports

Light detection and ranging (LiDAR) and terrestrial laser scanning (TLS) sensors are powerful tools for characterizing vegetation structure and for constructing three-dimensional (3D) models of trees, also known as quantitative structural models (QSM). 3D models and structural traits derived from them provide valuable information for biodiversity conservation, forest management, and fire behavior modeling. However, vegetation studies and 3D modeling methodologies often only focus on the forest canopy, with little attention given to understory vegetation. In particular, 3D structural information of shrubs is limited or not included in fire behavior models. Yet, understory vegetation is an important component of forested ecosystems, …


Frayed Connections: How Long-Term Nitrogen Additions Disrupt Plant-Soil Interactions And The Carbon Cycle Of A Temperate Forest, Brooke A. Eastman Jan 2022

Frayed Connections: How Long-Term Nitrogen Additions Disrupt Plant-Soil Interactions And The Carbon Cycle Of A Temperate Forest, Brooke A. Eastman

Graduate Theses, Dissertations, and Problem Reports

Forests are expected to mitigate some of the negative effects of climate change by sequestering anthropogenic carbon (C) from the atmosphere, but the degree to which they drawn down C will depend on the availability of key nutrients, such as nitrogen (N). There is a fair amount of uncertainty in the future of the forest C sink, mostly owing to the fate of soil organic matter (SOM) and soil heterotrophic respiration to future conditions. In N limited systems, plants allocate a significant amount of their photosynthate belowground for the acquisition of nutrients, but under conditions of chronic N deposition, plants …