Signature Of Obliquity And Eccentricity In Soil Chronosequences,
2018
University of Kentucky
Signature Of Obliquity And Eccentricity In Soil Chronosequences, Christopher Shepard, Jon D. Pelletier, Marcel G. Schaap, Craig Rasmussen
Plant and Soil Sciences Faculty Publications
Periodic shifts in Earth's orbit alter incoming solar radiation and drive Quaternary climate cycles. However, unambiguous detection of these orbitally driven climatic changes in records of terrestrial sedimentation and pedogenesis remains poorly defined, limiting our understanding of climate change‐landscape feedbacks, impairing our interpretation of terrestrial paleoclimate proxies, and limiting linkages among pedogenesis, sedimentation, and paleoclimatic change. Using a meta‐analysis, we show that Quaternary soil ages preserved in the modern record have periodicities of 41 and 98 kyr, consistent with orbital cycles. Further, soil ages predominantly date to periods of low rates of climatic change following rapid climate shifts associated with …
Crustal Seismic Anisotropy Of The Ruby Mountains Core Complex And Surrounding Northern Basin And Range,
2018
University of New Mexico
Crustal Seismic Anisotropy Of The Ruby Mountains Core Complex And Surrounding Northern Basin And Range, Justin T. Wilgus
Earth and Planetary Sciences ETDs
Metamorphic core complexes (MCC) are distinctive uplifts that expose deeply exhumed and deformed crustal rocks due to localized extensional deformation. Consequently, their detailed structure provide a window into deep crustal mechanics. The North American Cordillera contains numerous MCC, one of which is the Ruby Mountains core complex (RMCC) located in the highly extended northern Basin and Range. To constrain the extent to which anisotropy below the RMCC deviates from the regional Basin and Range average and test the depth dependence of crustal anisotropy we conduct a radial anisotropy investigation below the RMCC and surrounding northern Basin and Range. Data from …
The Cyrilka Cave—The Longest Crevice-Type Cave In Czechia: Structural Controls, Genesis, And Age,
2018
University of Ostrava
The Cyrilka Cave—The Longest Crevice-Type Cave In Czechia: Structural Controls, Genesis, And Age, Jan Lenart, Martin Kašing, Petr Tábořík, Natalia Piotrowska, Jacek Pawlyta
International Journal of Speleology
The Cyrilka Cave is the second longest pseudokarst cave and the longest crevice-type cave in Czechia. Developed within the headscarp area of a deep-seated landslide, the cave became a focus of scientific research in recent years when new passages were discovered. Structural analysis provided a general tectonic plan of the cave, as well as more detailed data on geometry and kinematics of the relaxed rock massif. The primary structure of NNE- to ENE-striking bedding is broken by a system of NNE-striking fissures interconnected by two continuous ENE-striking dextral fracture zones. Abundant signs of recent sinistral strike-slips within the rock massif …
New Borehole Breakout Derived Stress Constraints And Their Implications For Stress Heterogeneity Near High Risk Fault Systems In The Santa Barbara Channel, Southern California,
2018
Louisiana State University and Agricultural and Mechanical College
New Borehole Breakout Derived Stress Constraints And Their Implications For Stress Heterogeneity Near High Risk Fault Systems In The Santa Barbara Channel, Southern California, Edward Harris Pritchard
LSU Master's Theses
The Santa Barbara Channel represents the offshore portion of the Ventura Basin in Southern California. Ongoing transpression related to a regional left step in the San Andreas Fault has led to the formation of E-W trending en-echelon fault systems, with both north and south dips, which accommodate varying rates of localized shortening across the basin. Recent studies have suggested that faults within the northern region of the channel could be capable of a multisegment rupture and producing a Mw 7.7–8.1 tsunamigenic earthquake. However, dynamic rupture models producing these results have not accounted for stress heterogeneity, which is …
Direct Insertion Of Nasa Airborne Snow Observatory-Derived Snow Depth Time Series Into The Isnobal Energy Balance Snow Model,
2018
Boise State University
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,
2018
Boise State University
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,
2018
University of Nebraska-Lincoln
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,
2018
Boise State University
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,
2018
Boise State University
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,
2018
Boise State University
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 …
Sh-Mode Seismic-Reflection Imaging Of Earthfill Dams,
2018
University of Kentucky
Sh-Mode Seismic-Reflection Imaging Of Earthfill Dams, Edward W. Woolery
Earth and Environmental Sciences Faculty Publications
Assessing subsurface characteristics and imaging geologic features (e.g., faults, cavities, low-velocity layers, etc.) are typical problems in near-surface geophysics. These questions often have adverse geotechnical engineering implications, and can be especially acute when associated with high-hazard structures such as large earthen flood-control dams. Dam-related issues are becoming more frequent in the United States, because a large part of this major infrastructure was designed and constructed in the early- to mid-twentieth century; these dams are thus passing into the latter stages of their design life, where minute flaws that were overlooked or thought to be insignificant in design/construction are now …
Lithologic Controls On Focused Erosion And Intraplate Earthquakes In The Eastern Tennessee Seismic Zone,
2018
Colorado State University
Lithologic Controls On Focused Erosion And Intraplate Earthquakes In The Eastern Tennessee Seismic Zone, Sean F. Gallen, J. Ryan Thigpen
Earth and Environmental Sciences Faculty Publications
We present a new geomorphic model for the intraplate eastern Tennessee seismic zone (ETSZ). Previous studies document that the Upper Tennessee drainage basin is in a transient state of adjustment to ~150 m of base level fall that occurred in the Late Miocene. Using quantitative geomorphology, we demonstrate that base level fall resulted in the erosion of ~3,500 km3 of highly erodibility rock in an ~70 km wide by ~350‐km‐long corridor in the Paleozoic fold‐thrust belt above the ETSZ. Models of modern incision rates show a NE‐SW trending swath of elevated erosion ~30 km southeast of the center of …
The Crust And Upper Mantle Structure Of Central And West Antarctica From Bayesian Inversion Of Rayleigh Wave And Receiver Functions,
2018
Washington University in St. Louis
The Crust And Upper Mantle Structure Of Central And West Antarctica From Bayesian Inversion Of Rayleigh Wave And Receiver Functions, Weisen Shen, Audrey D. Huerta, J. Paul Winberry
All Faculty Scholarship for the College of the Sciences
We construct a new seismic model for central and West Antarctica by jointly inverting Rayleigh wave phase and group velocities along with P wave receiver functions. Ambient noise tomography exploiting data from more than 200 seismic stations deployed over the past 18 years is used to construct Rayleigh wave phase and group velocity dispersion maps. Comparison between the ambient noise phase velocity maps with those constructed using teleseismic earthquakes confirms the accuracy of both results. These maps, together with P receiver function waveforms, are used to construct a new 3-D shear velocity (Vs) model for the crust and uppermost mantle …
The Final Stages Of Slip And Volcanism On An Oceanic Detachment Fault At 13°48′N, Mid-Atlantic Ridge,
2018
Boise State University
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 …
On The Interaction Of The North Andes Plate With The Caribbean And South American Plates In Northwestern South America From Gps Geodesy And Seismic Data,
2018
Simón Bolivar University, Caracas
On The Interaction Of The North Andes Plate With The Caribbean And South American Plates In Northwestern South America From Gps Geodesy And Seismic Data, Omar J. Pérez, Steven G. Wesnousky, Roberto De La Rosa, Julio Márquez, Redescal Uzcátegui, Christian Quintero, Luis Liberal, Héctor Mora-Páez, Walter Szeliga
All Faculty Scholarship for the College of the Sciences
We examine the hypocentral distribution of seismicity and a series of geodetic velocity vectors obtained from Global Positioning System observations between 1994 and 2015 both offshore and mainland northwestern South America (66°W–77°W; 8°N–14°N). Our analysis, that includes a kinematic block modelling, shows that east of the Caribbean–South American–North Andes plates’ triple junction at ∼68°W; 10.7°N, right-lateral easterly oriented shear motion (∼19.6 ± 2.0 mm yr−1) between the Caribbean and South America plates is split along two easterly striking, right-lateral strike-slip subparallel fault zones: the San Sebastián fault that runs off-shore the Venezuelan coast and slips about 17.0±0.5mm …
Gps Constraints On Deformation In Northern Central America From 1999 To 2017, Part 1 – Time-Dependent Modelling Of Large Regional Earthquakes And Their Post-Seismic Effects,
2018
University of Wisconsin-Madison
Gps Constraints On Deformation In Northern Central America From 1999 To 2017, Part 1 – Time-Dependent Modelling Of Large Regional Earthquakes And Their Post-Seismic Effects, A. Ellis, Charles Demets, P. Briole, Beatriz Cosenza, Omar Flores, Shannon Graham, Marco Guzmán-Speziale, Douglas Hernandez, Vladimir Kostoglodov, Peter Lafemina, Neal Lord, Cécile Lasserre, Hélène Lyon-Caen, Manuel Rodriguez Maradiaga, Robert Mccaffrey, Enrique Molina, Jeffrey Rivera, Robert Rogers, Alejandra Staller
Geology Faculty Publications and Presentations
We use continuous and campaign measurements from 215 GPS sites in northern Central America and southern Mexico to estimate coseismic and afterslip solutions for the 2009 Mw = 7.3 Swan Islands fault strike-slip earthquake and the 2012 Mw = 7.3 El Salvador and Mw = 7.4 Guatemala thrust-faulting earthquakes on the Middle America trench. Our simultaneous, time-dependent inversion of more than 350 000 daily GPS site positions gives the first jointly consistent estimates of the coseismic slips for all three earthquakes, their combined time-dependent post-seismic effects and secular station velocities corrected for both the coseismic and post-seismic deformation. Our geodetic …
Gps Constraints On Deformation In Northern Central America From 1999 To 2017, Part 1 – Time-Dependent Modelling Of Large Regional Earthquakes And Their Post-Seismic Effects,
2018
University of Wisconsin-Madison
Gps Constraints On Deformation In Northern Central America From 1999 To 2017, Part 1 – Time-Dependent Modelling Of Large Regional Earthquakes And Their Post-Seismic Effects, A. Ellis, Charles Demets, P. Briole, Beatriz Cosenza, Omar Flores, Shannon E. Graham, Robert Mccaffrey, Multiple Additional Authors
Geology Faculty Publications and Presentations
We use continuous and campaign measurements from 215 GPS sites in northern Central America and southern Mexico to estimate coseismic and afterslip solutions for the 2009 Mw = 7.3 Swan Islands fault strike-slip earthquake and the 2012 Mw = 7.3 El Salvador and Mw = 7.4 Guatemala thrust-faulting earthquakes on the Middle America trench. Our simultaneous, time-dependent inversion of more than 350 000 daily GPS site positions gives the first jointly consistent estimates of the coseismic slips for all three earthquakes, their combined time-dependent post-seismic effects and secular station velocities corrected for both the coseismic and post-seismic …
Revelation Of Early Detection Of Coseismic Ionospheric Perturbations In Gps-Tec From Realistic Modelling Approach: Case Study,
2018
Indian Institute of Geomagnetism
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 …
Geomorphology Of Icy Debris Fans: Delivery Of Ice And Sediment To Valley Glaciers Decoupled From Icecaps,
2018
Bucknell University
Geomorphology Of Icy Debris Fans: Delivery Of Ice And Sediment To Valley Glaciers Decoupled From Icecaps, R. Craig Kochel, Jeffrey M. Trop, Robert W. Jacob
Faculty Journal Articles
The pace and volume of mass flow processes contributing ice and sediment to icy debris fans (IDFs) were documented at sites in Alaska and New Zealand by integrating field observations, drone and time-lapse imagery, ground penetrating radar, and terrestrial laser scanning. Largely unstudied, IDFs are supraglacial landforms at the mouths of bedrock catchments between valley glaciers and icecaps. Time-lapse imagery recorded 300–2300 events reaching 15 fans during intervals from nine months to two years. Field observations noted hundreds of deposits trapped within catchments weekly that were later remobilized onto fans. Deposits were mapped on images taken three to four times …
The Geotraces Intermediate Data Product 2017,
2018
Old Dominion University
The Geotraces Intermediate Data Product 2017, Reiner Schlitzer, Robert F. Anderson, Elena Masferrer Dodas, Maeve Lohan, Walter Geibert, Alessandro Tagliabue, Andrew Bowie, Gregory A. Cutter, Peter N. Sedwick, Bettina Sohst
OES Faculty Publications
The GEOTRACES Intermediate Data Product 2017 (IDP2017) is the second publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2016. The IDP2017 includes data from the Atlantic, Pacific, Arctic, Southern and Indian oceans, with about twice the data volume of the previous IDP2014. For the first time, the IDP2017 contains data for a large suite of biogeochemical parameters as well as aerosol and rain data characterising atmospheric trace element and isotope (TEI) sources. The TEI data in the IDP2017 are quality controlled by careful assessment of intercalibration results and …
