Geophysics and Seismology Commons^™

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

Geosciences Faculty Publications and Presentations

In this study, we focus on the electrical tortuosity-based permeability model k = r_eff²/8F (r_eff 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

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

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

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

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

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

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 …

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

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

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

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

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

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 …

Tephra From The 3 March 2015 Sustained Column Related To Explosive Lava Fountain Activity At Volcán Villarrica (Chile), Jeffrey B. Johnson

Geosciences Faculty Publications and Presentations

Exceptionally intense lava fountains at open conduit volcanoes are infrequent, hazardous and little-warned events. Studying their tephra falls may reveal conduit dynamics, eruption source parameters and fragmentation mechanisms. Villarrica Volcano (Southern Andes of Chile) has sustained persistent open conduit activity, associated with a dynamic lava lake since at least 1984–85. Increased seismicity and degassing in August 2014 were followed by Strombolian activity starting in February 2015 and culminated with a 1.5 km-high lava fountain on 3 March 2015. This eruption produced tephra fallout, spatter agglutination, clastogenic lavas and mixed avalanche deposits. Here we characterized for first time Villarrica's 3 March …

Identification Of Erosional Terraces On Seamounts: Implications For Interisland Connectivity And Subsidence In The Galápagos Archipelago, Darin M. Schwartz, S. Adam Soule, V. Dorsey Wanless, Meghan R. Jones

Geosciences Faculty Publications and Presentations

Shallow seamounts at ocean island hotspots and in other settings may record emergence histories in the form of submarine erosional terraces. Exposure histories are valuable for constraining paleo-elevations and sea levels in the absence of more traditional markers, such as drowned coral reefs. However, similar features can also be produced through primary volcanic processes, which complicate the use of terraced seamounts as an indicator of paleo-shorelines. In the western Galápagos Archipelago, we utilize newly collected bathymetry along with seafloor observations from human-occupied submersibles to document the location and depth of erosional terraces on seamounts near the islands of Santiago, Santa …

Eleven Years Of Mountain Weather, Snow, Soil Moisture And Streamflow Data From The Rain–Snow Transition Zone – The Johnston Draw Catchment, Reynolds Creek Experimental Watershed And Critical Zone Observatory, Usa, James P. Mcnamara

Geosciences Faculty Publications and Presentations

Detailed hydrometeorological data from the rain-to-snow transition zone in mountain regions are limited. As the climate warms, the transition from rain to snow is moving to higher elevations, and these changes are altering the timing of downslope water delivery. To understand how these changes impact hydrological and biological processes in this climatologically sensitive region, detailed observations from the rain-to-snow transition zone are required. We present a complete hydrometeorological dataset for water years 2004 through 2014 for a watershed that spans the rain-to-snow transition zone (https://doi.org/10.15482/usda.adc/1402076). The Johnston Draw watershed (1.8km²), ranging from 1497 to 1869m in elevation, is …

Hyporheic Source And Sink Of Nitrous Oxide, W. Jeffery Reeder, Annika M. Quick, Tiffany B. Farrell, Shawn G. Benner, Kevin P. Feris, Alessandra Marzadri, Daniele Tonina

Geosciences Faculty Publications and Presentations

Nitrous oxide (N₂O) is a potent greenhouse gas with an estimated 10% of anthropogenic N₂O coming from the hyporheic zone of streams and rivers. However, difficulty in making accurate fine-scale field measurements has prevented detailed understanding of the processes of N₂O production and emission at the bedform and flowline scales. Using large-scale, replicated flume experiments that employed high-density chemical concentration measurements, we have been able to refine the current conceptualization of N₂O production, consumption, and emission from the hyporheic zone. We present a predictive model based on a Damköhler-type transformation (τ̃) in …

Single-Station Seismo-Acoustic Monitoring Of Nyiragongo's Lava Lake Activity (D.R. Congo), Jeffrey B. Johnson

Geosciences Faculty Publications and Presentations

Since its last effusive eruption in 2002, Nyiragongo has been an open-vent volcano characterized by the world's largest persistent lava lake. This lava lake provides a unique opportunity to detect pressure change in the magmatic system by analyzing its level fluctuations. We demonstrate that this information is contained in the seismic and infrasound signals generated by the lava lake's activity. The continuous seismo-acoustic monitoring permits quantification of lava lake dynamics, which is analyzed retrospectively to identify periods of volcanic unrest. Synchronous, high-resolution satellite SAR (Synthetic Aperture Radar) images are used to constrain lava lake level by measuring the length of …

Landscape Analysis Of Soil Methane Flux Across Complex Terrain, Kendra E. Kaiser, Brian L. Mcglynn, John E. Dore

Geosciences Faculty Publications and Presentations

Relationships between methane (CH₄) fluxes and environmental conditions have been extensively explored in saturated soils, while research has been less prevalent in aerated soils because of the relatively small magnitudes of CH₄ fluxes that occur in dry soils. Our study builds on previous carbon cycle research at Tenderfoot Creek Experimental Forest, Montana, to identify how environmental conditions reflected by topographic metrics can be leveraged to estimate watershed scale CH₄ fluxes from point scale measurements. Here, we measured soil CH₄ concentrations and fluxes across a range of landscape positions (7 riparian, 25 upland), utilizing topographic and …

Steering Operational Synergies In Terrestrial Observation Networks: Opportunity For Advancing Earth System Dynamics Modelling, Roland Baatz, Pamela L. Sullivan, Li Li, Samantha R. Weintraub, Henry W. Loescher, Michael Mirtl, Peter M. Groffman, Diana H. Wall, Michael Young, Tim White, Hang Wen, Steffen Zacharias, Ingolf Kühn, Jianwu Tang, Jérôme Gaillardet, Isabelle Braud, Alejandro N. Flores, Praveen Kumar, Henry Lin, Teamrat Ghezzehei, Julia Jones, Henry L. Gholz, Harry Vereecken, Kris Van Looy

Geosciences Faculty Publications and Presentations

Advancing our understanding of Earth system dynamics (ESD) depends on the development of models and other analytical tools that apply physical, biological, and chemical data. This ambition to increase understanding and develop models of ESD based on site observations was the stimulus for creating the networks of Long-Term Ecological Research (LTER), Critical Zone Observatories (CZOs), and others. We organized a survey, the results of which identified pressing gaps in data availability from these networks, in particular for the future development and evaluation of models that represent ESD processes, and provide insights for improvement in both data collection and model integration. …

Lava, Ash Flows, Mudslides And Nasty Gases: Good Reasons To Respect Volcanoes, Brittany Brand

Geosciences Faculty Publications and Presentations

Volcanoes are beautiful and awe-inspiring, but the ongoing eruption of Kilauea on Hawaii’s Big Island is showing how dangerous these events can be. So far this event has destroyed dozens of homes and displaced hundreds of people, but no deaths or serious injuries have been reported. Other volcanic eruptions have had deadlier impacts.

Estimation Of Porosity And Water Saturation In Dual-Porosity Pyroclastic Deposits From Joint Analysis Of Compression, Shear, And Electromagnetic Velocities, Andrew C. Gase, John H. Bradford, Brittany D. Brand

Geosciences Faculty Publications and Presentations

In situ measurements of porosity and water saturation of pyroclastic deposits have the potential to improve interpretations of geology and hydrology in volcanic regions, and to provide more accurate estimates of dense rock equivalent for volcanic eruptions. However, rock-property models must consider the dual-porosity structure of pyroclastic deposits (i.e., vesicles within pumices and intergranular pores). Vesicularity, intergranular porosity, and water saturation all affect the density, elasticity, and dielectric properties of pyroclastic materials, which control seismic and electromagnetic velocities. The data from active seismic and ground-penetrating radar (GPR) techniques may improve porosity and water saturation estimation if the responses of seismic …

Spatial And Temporal Dynamics Of Dissolved Oxygen Concentrations And Bioactivity In The Hyporheic Zone, W. Jeffery Reeder, Annika M. Quick, Tiffany B. Farrell, Shawn G. Benner, Kevin P. Feris, Daniele Tonina

Geosciences Faculty Publications and Presentations

Dissolved oxygen (DO) concentrations and consumption rates are primary indicators of heterotrophic respiration and redox conditions in the hyporheic zone (HZ). Due to the complexity of hyporheic flow and interactions between hyporheic hydraulics and the biogeochemical processes, a detailed, mechanistic, and predictive understanding of the biogeochemical activity in the HZ has not yet been developed. Previous studies of microbial activity in the HZ have treated the metabolic DO consumption rate constant (K_DO) as a temporally fixed and spatially homogeneous property that is determined primarily by the concentration of bioavailable carbon. These studies have generally treated bioactivity as temporally …

Geologic Framework Of The Fang Hot Springs Area With Emphasis On Structure, Hydrology, And Geothermal Development, Chiang Mai Provence, Northern Thailand, Spencer H. Wood, Pichet Kaewsomwang, Fongsaward Suvagondha Singharajwarapan

Geosciences Faculty Publications and Presentations

Geologic mapping, a magnetotelluric survey, well data, and earlier reports are integrated to guide further development of the Fang geothermal system. The Fang Hot Springs originally flowed ~ 20 l s⁻¹ of 90–99 °C water from a 10-hectare area of crystal- line rocks presumed to be of Triassic age. Four wells 92–500 m deep now flow ~ 20 l s⁻¹ of 110–115 °C water and generate 115–250 kWe from the 1989 Ormat binary power plant. Wells are not pumped nor is the spent water re-injected. Temperatures of 130 °C occur in some wells and water chemistry indicates reservoir …

One Diamictite And Two Rifts: Stratigraphy And Geochronology Of The Gataga Mountain Of Northern British Columbia, Athena Eyster, Filippo Ferri, Mark D. Schmitz, Francis A. Macdonald

Geosciences Faculty Publications and Presentations

Neoproterozoic glacial diamictites and rift-related volcanics are preserved throughout the North American Cordillera, yet the nature and timing of both glaciation and rifting are poorly constrained. New geochronological, geochemical, and stratigraphic data from the Cryogenian Gataga volcanics and bounding units at Gataga Mountain, in the Kechika Trough of northern British Columbia, better constrain the age of these rift-related volcanics and suggest that they erupted during glaciation. At Gataga Mountain, three informal sequences are exposed; a basal quartzite, the Gataga volcanics, and an overlying mixed carbonate-siliciclastic succession. The basal quartzite is dominated by cross-bedded sandstone with an intertidal facies assemblage including …

Assessment Of Ground-Based And Aerial Cloud Seeding Using Trace Chemistry, James M. Fisher, Marion L. Lytle, Shawn G. Benner

Geosciences Faculty Publications and Presentations

Targeting seedable clouds with silver iodide in complex terrain adds considerable uncertainty in weather modification studies. This study explores the geographic and temporal distribution of silver iodide associated with an active cloud seeding program in central Idaho snowpack using trace chemistry. Over 4,000 snow samples were analyzed for the presence of a cloud seeding silver iodide (AgI) signature over two winter seasons. The results indicate the following. (1) At sites within 70 km of AgI sources, silver enrichments were detected at 88% of cases involving seeding efforts from ground generators, but none from aircraft seeded cases. (2) Real-time snow collection …

Petrology And Geochronology Of Metamorphic Zircon, Matthew J. Kohn, Nigel M. Kelly

Geosciences Faculty Publications and Presentations

Zircon is unusually well suited for investigating metamorphic processes because it is readily analyzed for U‐Pb ages, it harbors diverse mineral inclusions, and its chemistry can be linked to metamorphic parageneses and P‐T paths. Metamorphic zircon chemistry and ages are relevant only at the sub‐grain micron scale, and consequently many analytical methods, such as depth profiling, have been developed to exploit such spatially resolute infor­mation. Here we review how metamorphic zircon grows, and how its chemistry and inclusion assemblages may be used to link the age of a zircon domain to its metamorphic P‐T condition. Domain‐specific ages and inclusion assemblages …

Combined Assimilation Of Satellite Precipitation And Soil Moisture: A Case Study Using Trmm And Smos Data, Liao-Fan Lin, Ardeshir M. Ebtehaj, Alejandro N. Flores, Satish Bastola, Rafael L. Bras

Geosciences Faculty Publications and Presentations

This paper presents a framework that enables simultaneous assimilation of satellite precipitation and soil moisture observations into the coupled Weather Research and Forecasting (WRF) and Noah land surface model through variational approaches. The authors tested the framework by assimilating precipitation data from the Tropical Rainfall Measuring Mission (TRMM) and soil moisture data from the Soil Moisture Ocean Salinity (SMOS) satellite. The results show that assimilation of both TRMM and SMOS data can effectively improve the forecast skills of precipitation, top 10-cm soil moisture, and 2-m temperature and specific humidity. Within a 2-day time window, impacts of precipitation data assimilation on …