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Articles 271 - 300 of 667
Full-Text Articles in Earth Sciences
Partitioned By Process: Measuring Post-Fire Debris Flow And Rill Erosion With Structure From Motion, Nicholas Ellett
Partitioned By Process: Measuring Post-Fire Debris Flow And Rill Erosion With Structure From Motion, Nicholas Ellett
Boise State University Theses and Dissertations
In mountainous regions burned by wildfires, profound changes in soil characteristics and combustion of vegetation increase hillslope and channel erosion during storm events. Reduced infiltration and abundant loose sediment produce large post-fire erosional events which endanger human lives and infrastructure and contribute significantly to long-term erosion rates. While the influence of fire in increasing erosion has long been recognized, quantifying volumes and sources of eroded material from burned landscapes is difficult. Pre-erosion high-resolution topographic data (e.g. lidar) are often not available in burned areas and determining specific contributions from post-fire hillslope and channel erosion is challenging. Multiple erosional processes mobilize …
Petrogenesis Of Off-Axis Lavas Erupted Along The 8˚20’ N Seamount Chain, East Pacific Rise, Molly Kassandra Anderson
Petrogenesis Of Off-Axis Lavas Erupted Along The 8˚20’ N Seamount Chain, East Pacific Rise, Molly Kassandra Anderson
Boise State University Theses and Dissertations
Lavas erupted at off-axis seamounts provide a window into mantle heterogeneity and melting systematics that are not easily observed on-axis at fast spreading mid-ocean ridges (MORs). This is because axial melts are efficiently mixed and homogenized within shallow axial magma chambers prior to eruption. To understand the deeper magmatic processes contributing to oceanic crustal formation, we examine the compositions of lavas erupted along a chain of off-axis seamounts, adjacent to the East Pacific Rise (EPR). Essential questions include: (1) What is the range of compositional variability erupted off-axis and how does that compare to lavas erupted on-axis? (2) Is there …
Tsunamigenic Splay Faults Imply A Long‐Term Asperity In Southern Prince William Sound, Alaska, L. M. Liberty, D. S. Brothers, P. J. Haeussler
Tsunamigenic Splay Faults Imply A Long‐Term Asperity In Southern Prince William Sound, Alaska, L. M. Liberty, D. S. Brothers, P. J. Haeussler
CGISS Publications and Presentations
Coseismic slip partitioning and uplift over multiple earthquake cycles is critical to understanding upper‐plate fault development. Bathymetric and seismic reflection data from the 1964 Mw9.2 Great Alaska earthquake rupture area reveal sea floor scarps along the tsunamigenic Patton Bay/Cape Cleare/Middleton Island fault system. The faults splay from a megathrust where duplexing and underplating produced rapid exhumation. Trenchward of the duplex region, the faults produce a complex deformation pattern from oblique, south‐directed shortening at the Yakutat‐Pacific plate boundary. Spatial and temporal fault patterns suggest that Holocene megathrust earthquakes had similar relative motions and thus similar tsunami sources as in …
First-Order Estimates Of Coastal Bathymetry In Ilulissat And Naajarsuit Fjords, Greenland, From Remotely Sensed Iceberg Observations, Jessica Scheick, Ellyn M. Enderlin, Emily E. Miller, Gordon Hamilton
First-Order Estimates Of Coastal Bathymetry In Ilulissat And Naajarsuit Fjords, Greenland, From Remotely Sensed Iceberg Observations, Jessica Scheick, Ellyn M. Enderlin, Emily E. Miller, Gordon Hamilton
Geosciences Faculty Publications and Presentations
Warm water masses circulating at depth off the coast of Greenland play an important role in controlling rates of mass loss from the Greenland Ice Sheet through feedbacks associated with the melting of marine glacier termini. The ability of these warm waters to reach glacier termini is strongly controlled by fjord bathymetry, which was unmapped for the majority of Greenland’s fjords until recently. In response to the need for bathymetric measurements in previously uncharted areas, we developed two companion methods to infer fjord bathymetry using icebergs as depth sounders. The main premise of our methods centers around the idea that …
Permeability Prediction In Rocks Experiencing Mineral Precipitation And Dissolution: A Numerical Study, Qifei Niu, Chi Zhang
Permeability Prediction In Rocks Experiencing Mineral Precipitation And Dissolution: A Numerical Study, Qifei Niu, Chi Zhang
Geosciences Faculty Publications and Presentations
In this study, we focus on the electrical tortuosity-based permeability model k = reff2/8F (reff is an effective pore size, and F is the formation factor) and analyze its applicability to rocks experiencing mineral precipitation and dissolution. Two limiting cases of advection-dominated water-rock reactions are simulated, that is, the reaction-limited and transport-limited cases. At the pore scale, the two precipitation/dissolution patterns are simulated with a geometrical model and a phenomenological model. The fluid and electric flows in the rocks are simulated by directly solving the linear Stokes equation and Laplace equation on the representative …
Examining Interactions Between And Among Predictors Of Net Ecosystem Exchange: A Machine Learning Approach In A Semi-Arid Landscape, Qingtao Zhou, Aaron Fellows, Gerald N. Flerchinger, Alejandro N. Flores
Examining Interactions Between And Among Predictors Of Net Ecosystem Exchange: A Machine Learning Approach In A Semi-Arid Landscape, Qingtao Zhou, Aaron Fellows, Gerald N. Flerchinger, Alejandro N. Flores
Geosciences Faculty Publications and Presentations
Net ecosystem exchange (NEE) is an essential climate indicator of the direction and magnitude of carbon dioxide (CO2) transfer between land surfaces and the atmosphere. Improved estimates of NEE can serve to better constrain spatiotemporal characteristics of terrestrial carbon fluxes, improve verification of land models, and advance monitoring of Earth’s terrestrial ecosystems. Spatiotemporal NEE information developed by combining ground-based flux tower observations and spatiotemporal remote sensing datasets are of potential value in benchmarking land models. We apply a machine learning approach (Random Forest (RF)) to develop spatiotemporally varying NEE estimates using observations from a flux tower and several …
Hillslope Hydrology In Global Change Research And Earth System Modeling, A. Flores, J. Mcnamara
Hillslope Hydrology In Global Change Research And Earth System Modeling, A. Flores, J. Mcnamara
Geosciences Faculty Publications and Presentations
Earth System Models (ESMs) are essential tools for understanding and predicting global change, but they cannot explicitly resolve hillslope‐scale terrain structures that fundamentally organize water, energy, and biogeochemical stores and fluxes at subgrid scales. Here we bring together hydrologists, Critical Zone scientists, and ESM developers, to explore how hillslope structures may modulate ESM grid‐level water, energy, and biogeochemical fluxes. In contrast to the one‐dimensional (1‐D), 2‐ to 3‐m deep, and free‐draining soil hydrology in most ESM land models, we hypothesize that 3‐D, lateral ridge‐to‐valley flow through shallow and deep paths and insolation contrasts between sunny and shady slopes are the …
Including Variability Across Climate Change Projections In Assessing Impacts On Water Resources In An Intensively Managed Landscape, Bangshuai Han, Shawn G. Benner, Alejandro N. Flores
Including Variability Across Climate Change Projections In Assessing Impacts On Water Resources In An Intensively Managed Landscape, Bangshuai Han, Shawn G. Benner, Alejandro N. Flores
Geosciences Faculty Publications and Presentations
In intensively managed watersheds, water scarcity is a product of interactions between complex biophysical processes and human activities. Understanding how intensively managed watersheds respond to climate change requires modeling these coupled processes. One challenge in assessing the response of these watersheds to climate change lies in adequately capturing the trends and variability of future climates. Here we combine a stochastic weather generator together with future projections of climate change to efficiently create a large ensemble of daily weather for three climate scenarios, reflecting recent past and two future climate scenarios. With a previously developed model that captures rainfall-runoff processes and …
Probability Of Streamflow Permanence Model (Prosper): A Spatially Continuous Model Of Annual Streamflow Permanence Throughout The Pacific Northwest, K. E. Kaiser
Geosciences Faculty Publications and Presentations
The U.S. Geological Survey (USGS) has developed the PRObability of Streamflow PERmanence (PROSPER) model, a GIS raster-based empirical model that provides streamflow permanence probabilities (probabilistic predictions) of a stream channel having year-round flow for any unregulated and minimallyimpaired stream channel in the Pacific Northwest region, U.S. The model provides annual predictions for 2004–2016 at a 30-m spatial resolution based on monthly or annually updated values of climatic conditions and static physiographic variables associated with the upstream basin. Predictions correspond to any pixel on the channel network consistent with the medium resolution National Hydrography Dataset channel network stream grid. Total annual …
Late Permian And Early Triassic Conchostracans From The Babii Kamen Section (Kuznetsk Coal Basin), V. I. Davydov, V. V. Zharinova, V. V. Silantiev
Late Permian And Early Triassic Conchostracans From The Babii Kamen Section (Kuznetsk Coal Basin), V. I. Davydov, V. V. Zharinova, V. V. Silantiev
Geosciences Faculty Publications and Presentations
The Late Permian and Early Triassic conchostracans from the Babii Kamen section (Western Siberia) were studied. The conchostracans were collected from the section during the field work in 2015–2018. It was found that the conchostracans from the Babii Kamen section are characterized by a rather high taxonomical diversity: we identified five Late Permian conchostracan species (Pseudestheria novacastrensis (Mitchell, 1927), Cornia papillaria (Lutkevich, 1937), Megasitum harmonicum Novojilov, 1970, Megasitum lopokolense Novojilov, 1970, and Echinolimnadia mattoxi Novojilov, 1965) and two Early Triassic species (Concherisma tomensis Novojilov, 1958, Cyclotunguzites gutta (Lutkevich, 1938). The discovered conchostracan species occur frequently in the …
Applying Cloud-Based Computing And Emerging Remote Sensing Technologies To Inform Land Management Decisions, Monica Vermillion, Josh Enterkine, Lucas Spaete, Nancy Glenn
Applying Cloud-Based Computing And Emerging Remote Sensing Technologies To Inform Land Management Decisions, Monica Vermillion, Josh Enterkine, Lucas Spaete, Nancy Glenn
Geosciences Faculty Publications and Presentations
Who: Boise State University and Mountain Home Air Force Base
What: Creating a species level classification map through the use of Google Earth Engine (GEE), a cloud-based computing platform, to map invasive species
When: In-situ data collected in Summer 2018, a continuation of data collected in Summer 2016. Classification was created in Fall 2018. Unmanned aerial vehicles (UAV) flights in August 2018.
Where: Mountain Home Air Force Base (MHAFB) in southwest Idaho, ecosystem is in the Great Basin Range (GBR)
Why: The introduction of exotic species like cheatgrass (Bromus tectorum) has drastically altered the fire cycle of the …
Precaspian Isthmus Emergence Triggered The Early Sakmarian Glaciation (Paleontologic, Sedimentologic And Geochemical Proxies), Vladimir I. Davydov
Precaspian Isthmus Emergence Triggered The Early Sakmarian Glaciation (Paleontologic, Sedimentologic And Geochemical Proxies), Vladimir I. Davydov
Geosciences Faculty Publications and Presentations
The sub-meridional seaway that connected Paleo-Arctic and Paleo-Tethys basins was one of the most important geographical attributes of the Late Paleozoic Pangea landscape, paleogeography and paleoclimate. Existing models about the timing of the disconnection of the Paleo-Arctic and the Paleo-Tethyan oceans is very controversial and poorly documented. Warm-water benthic foraminifera (WWBF) were utilized to establish the precise timing of the closure of the Urals-Precaspian-Paleo-Tethys Seaway (UPTS) during Cisuralian time. The WWBF of Paleo-Tethys and those of the Ural-Precaspian Basins during the Gzhelian-Asselian, display a considerably high level of similarity. Beginning from the Sakmarian, the faunas of these two regions became …
Volcano Infrasound Monitoring With Applications For Statistical Forecasting Of Explosions At Sakurajima (Japan), Matthew R. Vonlintig
Volcano Infrasound Monitoring With Applications For Statistical Forecasting Of Explosions At Sakurajima (Japan), Matthew R. Vonlintig
Boise State University Theses and Dissertations
Volcanic eruptions are powerful natural phenomena that often occur unpredictably in time and magnitude. Nearby communities are put at risk during volcanic unrest; however, when hazards are well understood and clearly defined risk can be mitigated. This thesis addresses the problem of forecasting the likelihood of future explosive volcanic behavior by monitoring ongoing eruptive history with infrasound. I parameterize inter-event temporal behavior to determine the eruption controlling processes is material failure opposed to changes in magma and volatile supply.
I analyze data from Sakurajima, a type-example open volcano, using two local (4 km from the vent) microphone arrays, which recorded …
Cross-Scale Interactions Between Atmospheric And Hydrologic Processes In A Topographically Complex, Snow-Dominated Watershed As Revealed Through An Integrated Hydrologic Model, Miguel A. Aguayo Arias
Cross-Scale Interactions Between Atmospheric And Hydrologic Processes In A Topographically Complex, Snow-Dominated Watershed As Revealed Through An Integrated Hydrologic Model, Miguel A. Aguayo Arias
Boise State University Theses and Dissertations
In much of the world, water for agricultural, domestic, and hydroelectric power generation uses are derived from snow-dominated mountain basins. In these regions, water management requires accurate and timely knowledge of runoff generation by snowmelt. This information is used to plan reservoir releases for downstream users and is generated by models of biophysical processes associated with varying degrees of fidelity to physical processes and/or spatial heterogeneities. The large variability in the characteristic spatial and temporal scales of atmospheric forcings, land-surface water and energy balance, and groundwater flow contribute to significant uncertainties in resolved hydrologic states and fluxes. Underlying sources of …
Pressure Waves And Tephra Dispersal From Volcanic Explosions: Models, Observations, And Instrumentation, Jacob Fortner Anderson
Pressure Waves And Tephra Dispersal From Volcanic Explosions: Models, Observations, And Instrumentation, Jacob Fortner Anderson
Boise State University Theses and Dissertations
Real-time study of erupting vents is important for both monitoring and scientific purposes; because direct in-situ study of erupting vents is impractical, our best tools for studying eruptions in real time involve monitoring eruptive products and waves that travel far from the volcano. The atmosphere is a particularly advantageous medium for studying propagation and transport of volcanic waves and products: acoustic waves pass through it with minimal scattering, particles follow predictable trajectories, and the atmospheric structure that affects both is well-monitored. Analyses of acoustic waves and tephra deposits can provide important information on eruptions including total explosive energy, volume, and …
Correlating The Spatial Distribution Of Snow Depth To Forest Canopy Parameters Derived From Terrestrial Laser Scans, Zachary Uhlmann
Correlating The Spatial Distribution Of Snow Depth To Forest Canopy Parameters Derived From Terrestrial Laser Scans, Zachary Uhlmann
Boise State University Theses and Dissertations
In nonpolar, cold climate zones, snow accounts for 17% of the total terrestrial water storage. Estimating the amount of water stored in a snowpack, the snow water equivalent (SWE), and its spatial distribution is crucial to providing water managers with parameters to predict runoff timing, duration and amount. Reservoir management, hydropower and flood forecasting depend on SWE estimates. While landscape features such as aspect and slope are dominant controls on radiative energy in non-forested areas, forest cover can shift the energy balance composition from turbulent exchange in exposed, windy sites to primarily radiative inputs in the subcanopy. Additionally, forest cover …
Investigating The Annual Water Balance Of A High-Altitude Watershed Using Near-Real Time Lidar Data Integration Into A Physically Based Snowmelt Model, Andrew R. Hedrick
Investigating The Annual Water Balance Of A High-Altitude Watershed Using Near-Real Time Lidar Data Integration Into A Physically Based Snowmelt Model, Andrew R. Hedrick
Boise State University Theses and Dissertations
Knowledge of the amount of water stored in the mountain snowpack is crucial for flood prevention, drought mitigation, and energy production in the Western United States. In modeling terms, the most important component of the hydrologic water balance is the precipitation input to the system. Determining where and how much precipitation falls in mountain catchments, however, is the most difficult problem with regards to closing the water balance. The work presented in this dissertation details the modeling portion of the NASA Airborne Snow Observatory (ASO) using the iSnobal physically based snow model. This combination of remote sensing and modeling at …
Stable Isotope Geochemistry Of Bioapatite, Amanda E. Drewicz
Stable Isotope Geochemistry Of Bioapatite, Amanda E. Drewicz
Boise State University Theses and Dissertations
The Cenozoic Era was a time period where dynamic shifts in climate created for both warm-wet greenhouse environments of the mid-Miocene Climatic Optimum (MMCO), and cool-dry, glacial periods of the late Pleistocene. The Cenozoic is close to our own time period, and although past climate reconstructions cannot be used as direct analogs for future climate change, understanding previous environmental responses can help inform policy surrounding future climate change. Presented here are climate reconstructions of the interior western United States, from two different geologic time periods. Each had a different climate, that differed greatly from modern day environments. The use of …
Post-Fire Variation In Aeolian Deposition In The Northern Great Basin, Clayton Roehner
Post-Fire Variation In Aeolian Deposition In The Northern Great Basin, Clayton Roehner
Boise State University Theses and Dissertations
Aeolian processes play a significant role in the redistribution of sediment and nutrients in sparsely vegetated sagebrush-steppe ecosystems. When fire is introduced to the landscape, decreased surface roughness and associated threshold friction velocities allow for the increased mobility of surface sediments and burnt organic material, mobilizing previously stable material. Once material is entrained, interactions between a dynamic atmosphere and complex topography control the spatial distribution of aeolian deposition over a landscape. Given the significant impact of fire on aeolian processes in semi-arid deserts, we posit that postfire aeolian redistribution of material is an important control on the spatial variability of …
Evaluating Stable Isotope And Geochronologic Techniques For Paleoclimate Reconstruction: Case Study Of The Santa Cruz Formation, Argentina, Robin B. Trayler
Evaluating Stable Isotope And Geochronologic Techniques For Paleoclimate Reconstruction: Case Study Of The Santa Cruz Formation, Argentina, Robin B. Trayler
Boise State University Theses and Dissertations
Stable isotope analysis has become the method of choice for many studies investigating the paleoecology and paleoclimate of fossil mammal faunas. While organic tissues (collagen, keratins, proteins) persist for < 105 years highly mineralized tooth enamel is resistant to alteration and degradation and faithfully preserves its isotopic composition for millions (> 106) years. Reconstructing past climates from these records relies on both understanding both micro-scale mechanisms of isotope incorporation into individual teeth, and macro-scale changes in isotope compositions over hundreds of thousands or millions of years. In this dissertation I address three questions.
First, how does the geometry and …
Crustal Composition Beneath Southern Idaho: Insights From Teleseismic Receiver Functions, Thomas Branson Harper
Crustal Composition Beneath Southern Idaho: Insights From Teleseismic Receiver Functions, Thomas Branson Harper
Boise State University Theses and Dissertations
Receiver functions derived from teleseismic earthquakes contain seismic amplitude and velocity information that relate to compositional changes within the Earth’s crust and upper mantle. The receiver function waveform is a combination of P-S converted waves that have reverberated within the lithosphere. Although the largest seismic velocity boundary is found at the base of the crust, I explore the use of lower amplitude receiver function arrivals that represent smaller velocity contrasts within the crust. In my thesis, I calculate and model receiver functions via a Metropolis algorithm approach to extract seismic velocity distributions in the lithosphere. I use the results to …
Interannual Snow Accumulation Variability On Glaciers Derived From Repeat, Spatially Extensive Ground-Penetrating Radar Surveys, Daniel Mcgrath, Louis Sass, Shad O'Neel, Chris Mcneil, Salvatore G. Candela, Emily H. Baker, Hans-Peter Marshall
Interannual Snow Accumulation Variability On Glaciers Derived From Repeat, Spatially Extensive Ground-Penetrating Radar Surveys, Daniel Mcgrath, Louis Sass, Shad O'Neel, Chris Mcneil, Salvatore G. Candela, Emily H. Baker, Hans-Peter Marshall
CGISS Publications and Presentations
There is significant uncertainty regarding the spatiotemporal distribution of seasonal snow on glaciers, despite being a fundamental component of glacier mass balance. To address this knowledge gap, we collected repeat, spatially extensive high-frequency ground-penetrating radar (GPR) observations on two glaciers in Alaska during the spring of 5 consecutive years. GPR measurements showed steep snow water equivalent (SWE) elevation gradients at both sites; continental Gulkana Glacier's SWE gradient averaged 115 mm 100 m−1 and maritime Wolverine Glacier's gradient averaged 440 mm 100 m−1 (over > 1000 m). We extrapolated GPR point observations across the glacier surface using terrain parameters derived …
Direct Insertion Of Nasa Airborne Snow Observatory-Derived Snow Depth Time Series Into The Isnobal Energy Balance Snow Model, Andrew R. Hedrick, Hans-Peter Marshall
Direct Insertion Of Nasa Airborne Snow Observatory-Derived Snow Depth Time Series Into The Isnobal Energy Balance Snow Model, Andrew R. Hedrick, Hans-Peter Marshall
CGISS Publications and Presentations
Accurately simulating the spatiotemporal distribution of mountain snow water equivalent improves estimates of available meltwater and benefits the water resource management community. In this paper we present the first integration of lidar-derived distributed snow depth data into a physics-based snow model using direct insertion. Over four winter seasons (2013–2016) the National Aeronautics and Space Administration/Jet Propulsion Laboratory (NASA/JPL) Airborne Snow Observatory (ASO) performed near-weekly lidar surveys throughout the snowmelt season to measure snow depth at high resolution over the Tuolumne River Basin above Hetch Hetchy Reservoir in the Sierra Nevada Mountains of California. The modeling component of the ASO program …
Climate Change And Curtailment: Evaluating Water Management Practices In The Context Of Changing Runoff Regimes In A Snowmelt-Dominated Basin, Amy L. Steimke, Bangshuai Han, Jodi S. Brandt, Alejandro N. Flores
Climate Change And Curtailment: Evaluating Water Management Practices In The Context Of Changing Runoff Regimes In A Snowmelt-Dominated Basin, Amy L. Steimke, Bangshuai Han, Jodi S. Brandt, Alejandro N. Flores
Geosciences Faculty Publications and Presentations
Hydrologic scientists and water resource managers often focus on different facets of flow regimes in changing climates. The objective of this work is to examine potential hydrological changes in the Upper Boise River Basin, Idaho, USA in the context of biophysical variables and their impacts a key variable governing administration of water resources in the region in an integrated way. This snowmelt-dominated, mountainous watershed supplies water to a semi-arid, agriculturally intensive, but rapidly urbanizing, region. Using the Envision integrated modeling framework, we created a hydrological model to simulate hydrological response to the year 2100 using six alternative future climate trajectories. …
Imaging Spectroscopic Analysis Of Biochemical Traits For Shrub Species In Great Basin, Usa, Yi Qi, Susan L. Ustin, Nancy F. Glenn
Imaging Spectroscopic Analysis Of Biochemical Traits For Shrub Species In Great Basin, Usa, Yi Qi, Susan L. Ustin, Nancy F. Glenn
Geosciences Faculty Publications and Presentations
The biochemical traits of plant canopies are important predictors of photosynthetic capacity and nutrient cycling. However, remote sensing of biochemical traits in shrub species in dryland ecosystems has been limited mainly due to the sparse vegetation cover, manifold shrub structures, and complex light interaction between the land surface and canopy. In order to examine the performance of airborne imaging spectroscopy for retrieving biochemical traits in shrub species, we collected Airborne Visible Infrared Imaging Spectrometer—Next Generation (AVIRIS-NG) images and surveyed four foliar biochemical traits (leaf mass per area, water content, nitrogen content and carbon) of sagebrush (Artemesia tridentata) and …
Reverse-Time Migration From Rugged Topography To Image Ground-Penetrating Radar Data In Complex Environments, John H. Bradford, Janna Privette, David Wilkins, Richard Ford
Reverse-Time Migration From Rugged Topography To Image Ground-Penetrating Radar Data In Complex Environments, John H. Bradford, Janna Privette, David Wilkins, Richard Ford
Geosciences Faculty Publications and Presentations
In ground-penetrating radar (GPR) imaging, it is common for the depth of investigation to be on the same order as the variability in surface topography. In such cases, migration fails when it is carried out from a datum after the application of elevation statics. We introduce a reverse-time migration (RTM) algorithm based on the second-order decoupled form of Maxwell’s equations, which requires computation of only the electric field. The wavefield extrapolation is computed directly from the acquisition surface without the need for datuming. In a synthetic case study, the algorithm significantly improves image accuracy over a processing sequence in which …
Nested Scales Of Spatial And Temporal Variability Of Soil Water Content Across A Semiarid Montane Catchment, Kendra E. Kaiser, Brian L. Mcglynn
Nested Scales Of Spatial And Temporal Variability Of Soil Water Content Across A Semiarid Montane Catchment, Kendra E. Kaiser, Brian L. Mcglynn
Geosciences Faculty Publications and Presentations
Topographic redistribution of water has been represented by various terrain metrics (e.g., topographic wetness index, slope, and upslope accumulated area). This type of landscape characterization has promoted the use of terrain metrics to inform how spatial patterns of soil volumetric water content (VWC) influence streamflow, ecological processes, and associated nutrient fluxes. However, evaluation of what these static terrain metrics reflect has only been accomplished in a few catchments. Additionally, previous research suggests that relationships between topographic metrics and VWC could be different across catchments through time. Here we measured VWC from snowmelt through summer drydown across a semiarid montane catchment. …
Submarine Deep-Water Lava Flows At The Base Of The Western Galápagos Platform, Molly Anderson, V. Dorsey Wanless, Darin M. Schwartz, Emma Mccully, Daniel J. Fornari, Meghan R. Jones, S. Adam Soule
Submarine Deep-Water Lava Flows At The Base Of The Western Galápagos Platform, Molly Anderson, V. Dorsey Wanless, Darin M. Schwartz, Emma Mccully, Daniel J. Fornari, Meghan R. Jones, S. Adam Soule
Geosciences Faculty Publications and Presentations
To investigate the initial phases of magmatism at the leading edge of the upwelling mantle plume, we mapped, photographed, and collected samples from two long, deep-water lava flows located at the western base of the Galápagos Platform using the remotely operated vehicle Hercules. Lavas were recovered from four areas on the seafloor west of Fernandina volcano, including the western flow fronts of two deep-water flows, heavily sedimented terrain between the two flows, and the eastern, shallower end of one flow. The sediment cover and morphologies are distinct between the western flow fronts and the eastern region based on seafloor …
The Final Stages Of Slip And Volcanism On An Oceanic Detachment Fault At 13°48′N, Mid-Atlantic Ridge, V. D. Wanless
The Final Stages Of Slip And Volcanism On An Oceanic Detachment Fault At 13°48′N, Mid-Atlantic Ridge, V. D. Wanless
Geosciences Faculty Publications and Presentations
While processes associated with initiation and maintenance of oceanic detachment faults are becoming better constrained, much less is known about the tectonic and magmatic conditions that lead to fault abandonment. Here we present results from near‐bottom investigations using the submersible Alvin and autonomous underwater vehicle Sentry at a recently extinct detachment fault near 13°48′N, Mid‐Atlantic Ridge, that allow documentation of the final stages of fault activity and magmatism. Seafloor imagery, sampling, and near‐bottom magnetic data show that the detachment footwall is intersected by an ~850 m‐wide volcanic outcrop including pillow lavas. Saturation pressures in these vesicular basalts, based on dissolved …
Revelation Of Early Detection Of Coseismic Ionospheric Perturbations In Gps-Tec From Realistic Modelling Approach: Case Study, Dhanya Thomas, Mala S. Bagiya, Poikayil Sukumaran Sunil, Lucie Rolland, Anakuzhikkal Sudarsanan Sunil, T. Dylan Mikesell, Srinivas Nayak, Subrahmanyam Mangalampalli, Durbha Sai Ramesh
Revelation Of Early Detection Of Coseismic Ionospheric Perturbations In Gps-Tec From Realistic Modelling Approach: Case Study, Dhanya Thomas, Mala S. Bagiya, Poikayil Sukumaran Sunil, Lucie Rolland, Anakuzhikkal Sudarsanan Sunil, T. Dylan Mikesell, Srinivas Nayak, Subrahmanyam Mangalampalli, Durbha Sai Ramesh
CGISS Publications and Presentations
GPS-derived Total Electron Content (TEC) is an integrated quantity; hence it is difficult to relate the detection of ionospheric perturbations in TEC to a precise altitude. As TEC is weighted by the maximum ionospheric density, the corresponding altitude (hmF2) is, generally, assumed as the perturbation detection altitude. To investigate the validity of this assumption in detail, we conduct an accurate analysis of the GPS-TEC measured early ionospheric signatures related to the vertical surface displacement of the Mw 7.4 Sanriku-Oki earthquake (Sanriku-Oki Tohoku foreshock). Using 3D acoustic ray tracing model to describe the evolution of the propagating seismo-acoustic wave in space …