Earth Sciences Commons^™

Evaluation Of Glaciogenic Cloud Seeding Using Trace Chemistry, James M. Fisher, Marion L. Lytle, Shawn G. Benner

Geosciences Faculty Publications and Presentations

Glaciogenic cloud seeding with silver iodide (AgI) has been used to enhance precipitation for over 60 years. Assessments of AgI impact and dispersion are often quantified using atmospheric processes models with impact assessed by comparing models with and without the inclusion of cloud seeding modules. However, there is inherent uncertainty in these models. Quantifying AgI distribution in the snowpack following cloud seeding can both validate and improve model performance. The purpose of this study is to demonstrate the capacity to document the dispersion of AgI by measuring silver (Ag) enrichments in snow.

This study develops clean field and laboratory procedures …

Carbon Isotope Discrimination In C3 Land Plants Is Independent Of Natural Variations In PCo2, M. J. Kohn

Geosciences Faculty Publications and Presentations

The δ¹³C of terrestrial C3 plant tissues and soil organic matter is important for understanding the carbon cycle, inferring past climatic and ecological conditions, and predicting responses of vegetation to future climate change. Plant δ¹³C depends on the δ¹³C of atmospheric CO₂ and and mean annual precipitation (MAP), but an unresolved decades-long debate centres on whether terrestrial C3 plant δ¹³C responds to p_CO2. In this study, the p_CO2-dependence of C3 land plant δ¹³C was tested using isotopic records from low- and high-p_{CO …}

Advancements In The Measurement Of The Cryosphere Using Geophysics — Introduction, Andrew D. Parsekian, John Bradford, Georgios Tsoflias, Steven Arcone, Bernd Kulessa

CGISS Publications and Presentations

Frozen regions of the earth are known as the cryosphere. The arctic, Antarctica, permafrost, ice sheets, and glaciers are some of the most challenging places to measure subsurface parameters, but they can also be some of the most important places to science and engineering research due to their susceptibility to environmental change. Ground-based, airborne, and space-borne geophysical methods are deployed to observe targets below the ground or in ice that may be difficult or impossible to measure using conventional direct observations and measurements. The papers in this special section address recent advances in instrumentation development and deployment and computational capabilities …

Muang Rae Geothermal System: Drilling And Borehole Geophysics, 1000-M Core Hole Into Granitic Rock, Amphoe Pai, Mae Hong Son Province, Northern Thailand, Spencer H. Wood, Kriangsak Pirarai, Aranya Fuangswasdi, Wiboon Kaentao, Albert Waibel, Fongsaward S. Singharajwarapan

Geosciences Faculty Publications and Presentations

In 2015, a 1-km core hole was drilled into granitic rock at the Muang Rae geothermal area. Previous drilling in 1993 to 200 m was unsuccessful in obtaining flows, but one of the “dry” wells began flowing in August, 2013 at 9.75 L/s of 96.9°C water from a fracture zone 80 m deep. In the sandy bed of the Pai River, 150 m south of that well is a 600-m long line of hot seeps, oriented NE, with highest temperature measured at 94.5°C. Geology is foliated Triassic (?) granitic rock cut by a NE-SW-trending normal fault zone (dip 65° NW) …

Targeted Reflection-Waveform Inversion Of Experimental Ground-Penetrating Radar Data For Quantification Of Oil Spills Under Sea Ice, John H. Bradford, Esther L. Babcock, Hans-Peter Marshall, David F. Dickins

Geosciences Faculty Publications and Presentations

Rapid spill detection and mapping are needed with increasing levels of oil exploration and production in the Arctic. Previous work has found that ground-penetrating radar (GPR) is effective for qualitative identification of oil spills under, and encapsulated within, sea ice. Quantifying the spill distribution will aid effective spill response. To this end, we have developed a targeted GPR reflection-waveform inversion algorithm to quantify the geometry of oil spills under and within sea ice. With known electric properties of the ice and oil, we have inverted for oil thickness and variations in ice thickness. We have tested the algorithm with data …

A Synthetic Study To Assess The Applicability Of Full-Waveform Inversion To Infer Snow Stratigraphy From Upward-Looking Ground-Penetrating Radar Data, Lino Schmid, Jürg Schweizer, John Bradford, Hansruedi Maurer

CGISS Publications and Presentations

Snow stratigraphy and liquid water content are key contributing factors to avalanche formation. Upward-looking ground penetrating radar (upGPR) systems allow nondestructive monitoring of the snowpack, but deriving density and liquid water content profiles is not yet possible based on the direct analysis of the reflection response. We have investigated the feasibility of deducing these quantities using full-waveform inversion (FWI) techniques applied to upGPR data. For that purpose, we have developed a frequency-domain FWI algorithm in which we additionally took advantage of time-domain features such as the arrival times of reflected waves. Our results indicated that FWI applied to upGPR data …

Re-Assessment Of Lithostratigraphy, Biostratigraphy, And Volcanic Activity Of The Late Paleozoic Intra-Sudetic, Krkonoše-Piedmont And Mnichovo Hradiště Basins (Czech Republic) Based On New U-Pb Ca-Id-Tims Ages, Stanislav Opluštil, Mark Schmitz, Václav Kachlík, Stanislav Štamberg

Geosciences Faculty Publications and Presentations

Five U-Pb CA-ID-TIMS high-precision ages were obtained from single zircon crystals separated from tuffs or ignimbrites embedded in Pennsylvanian to Asselian sediments of the Intra-Sudetic, Krkonoše-Piedmont and the adjacent part of the Mnichovo Hradiště basins. The new radioisotopic data are used for extrapolation of ages of dated lithostratigraphic units. The existing borehole network in the Late Paleozoic continental basins of central and western Bohemia and in the Sudetic area, and similarity of their stratigraphically equivalent strata including some common lacustrine horizons allow a detailed lithostratigraphical correlation between these two areas. This in turn, allows combining our new radioisotopic data with …

A Preliminary Assessment Of Water Partitioning And Ecohydrological Coupling In Northern Headwaters Using Stable Isotopes And Conceptual Runoff Models, James P. Mcnamara

Geosciences Faculty Publications and Presentations

We combined a conceptual rainfall-runoff model and input–output relationships of stable isotopes to understand ecohydrological influences on hydrological partitioning in snow-influenced northern catchments. Six sites in Sweden (Krycklan), Canada (Wolf Creek; Baker Creek; Dorset), Scotland (Girnock) and the USA (Dry Creek) span moisture and energy gradients found at high latitudes. A meta-analysis was carried out using the Hydrologiska Byråns Vattenbalansavdelning (HBV) model to estimate the main storage changes characterizing annual water balances. Annual snowpack storage importance was ranked as Wolf Creek > Krycklan > Dorset > Baker Creek > Dry Creek > Girnock. The subsequent rate and longevity of melt were reflected in calibrated parameters …

Natural Degradation Of Earthworks, Trenches, Walls And Moats, Northern Thailand, Spencer H. Wood, Layle R. Wood, Alan D. Ziegler

Geosciences Faculty Publications and Presentations

“………..structures of this kind are hidden away securely under the thick overgrowth: thus does nature preserve what man would surely destroy” (from Sumet Jumsai, 1970)

We investigate the geometry, age, and history of several enigmatic northern Thailand earthwork entrenchments that are mostly located on hills and could not have held water to form moats. The earthworks are either oval or rectangular in map view; and they typically encircle 0.3-to-1-km² areas that do not have potsherd debris indicative of former towns. Most trenches are 3-5 m deep with inner walls 4.5-8 m high. Some encircling earthworks are concentric double trenches …

Infrasound From Volcanic Rockfalls, Jeffrey B. Johnson, Timothy J. Ronan

CGISS Publications and Presentations

Proximal infrasound arrays can robustly track rapidly moving gravity-driven mass wasting, which occurs commonly at erupting volcanoes. This study reports on detection, localization, and quantification of frequent small rockfalls and infrequent pyroclastic density currents descending the southeast flanks of Santiaguito’s active Caliente Dome in January of 2014. Such activities are identified as moving sources, which descend several hundred meters at bulk flow speeds of up to ~10 m/s, which is considerably slower than the descent velocity of individual blocks. Infrasound rockfall signal character is readily distinguishable from explosion infrasound, which is manifested by a relatively fixed location source with lower …

Streambed And Water Profile Response To In-Channel Restoration Structures In A Laboratory Meandering Stream, Bangshuai Han, Hong-Hanh Chu, Theodore A. Endreny

Geosciences Faculty Publications and Presentations

In-channel structures are often installed in alluvial rivers during restoration to steer currents, but they also modify the streambed morphology and water surface profile, and alter hydraulic gradients driving ecologically important hyporheic exchange. Although river features before and after restoration need to be compared, few studies have collected detailed observations to facilitate this comparison. We created a laboratory mobile-bed alluvial meandering river and collected detailed measurements in the highly sinuous meander before and after installation of in-channel structures, which included one cross vane and six J-hooks situated along 1 bar unit. Measurements of streambed and water surface elevation with sub-millimeter …

Landslides And Megathrust Splay Faults Captured By The Late Holocene Sediment Record Of Eastern Prince William Sound, Alaska, Shaun P. Finn, Lee M. Liberty, Peter J. Haeussler, Thomas L. Pratt

Geosciences Faculty Publications and Presentations

We present new marine seismic‐reflection profiles and bathymetric maps to characterize Holocene depositional patterns, submarine landslides, and active faults beneath eastern and central Prince William Sound (PWS), Alaska, which is the eastern rupture patch of the 1964 M_w 9.2 earthquake. We show evidence that submarine landslides, many of which are likely earthquake triggered, repeatedly released along the southern margin of Orca Bay in eastern PWS. We document motion on reverse faults during the 1964 Great Alaska earthquake and estimate late Holocene slip rates for these growth faults, which splay from the subduction zone megathrust. Regional bathymetric lineations help define …

Seasonal And Diurnal Cycles Of Liquid Water In Snow—Measurements And Modeling, A. Heilig, C. Mitterer, L. Schmid, N. Wever, J. Schweizer, H.-P. Marshall, O. Eisen

CGISS Publications and Presentations

Evaluating and improving snow models and outflow predictions for hydrological applications is hindered by the lack of continuous data on bulk volumetric liquid water content (��_w) and storage capacity of the melting snowpack. The combination of upward looking ground-penetrating radar and conventional snow height sensors enable continuous, nondestructive determinations of ��_w in natural snow covers from first surficial wetting until shortly before melt out. We analyze diurnal and seasonal cycles of ��_w for 4 years in a flat study site and for three melt seasons on slopes and evaluate model simulations for two different water …

Source Mechanism Of Small Long-Period Events At Mount St. Helens In July 2005 Using Template Matching, Phase-Weighted Stacking, And Full-Waveform Inversion, Robin S. Matoza, Bernard A. Chouet, Phillip B. Dawson, Peter M. Shearer, Matthew M. Haney, Gregory P. Waite, Seth C. Moran, T. Dylan Mikesell

CGISS Publications and Presentations

Long-period (LP, 0.5-5 Hz) seismicity, observed at volcanoes worldwide, is a recognized signature of unrest and eruption. Cyclic LP “drumbeating” was the characteristic seismicity accompanying the sustained dome-building phase of the 2004–2008 eruption of Mount St. Helens (MSH), WA. However, together with the LP drumbeating was a near-continuous, randomly occurring series of tiny LP seismic events (LP “subevents”), which may hold important additional information on the mechanism of seismogenesis at restless volcanoes. We employ template matching, phase-weighted stacking, and full-waveform inversion to image the source mechanism of one multiplet of these LP subevents at MSH in July 2005. The signal-to-noise …

Hydrological Partitioning In The Critical Zone: Recent Advances And Opportunities For Developing Transferable Understanding Of Water Cycle Dynamics, Paul D. Brooks, Jon Chorover, Ying Fan, Sarah E. Godsey, Reed M. Maxwell, James P. Mcnamara, Christina Tague

Geosciences Faculty Publications and Presentations

Hydrology is an integrative discipline linking the broad array of water-related research with physical, ecological, and social sciences. The increasing breadth of hydrological research, often where subdisciplines of hydrology partner with related sciences, reflects the central importance of water to environmental science, while highlighting the fractured nature of the discipline itself. This lack of coordination among hydrologic subdisciplines has hindered the development of hydrologic theory and integrated models capable of predicting hydrologic partitioning across time and space. The recent development of the concept of the critical zone (CZ), an open system extending from the top of the canopy to the …

Lahar Infrasound Associated With Volcán Villarrica's 3 March 2015 Eruption, Jeffrey B. Johnson, Jose L. Palma

Geosciences Faculty Publications and Presentations

The paroxysmal 2015 eruption of Volcán Villarrica (Chile) produced a 2.5 h long lahar, which descended more than 20 km within the Rio Correntoso/Turbio drainage and destroyed two small bridges. A three-element infrasound array 10 km from the summit, and 4 km from the lahar’s closest approach, was used to study the flow’s progression. Array processing using cross-correlation lag times and semblance places constraints on the lahar’s dynamics, including detection of an initial flow pulse that traveled from 2 to 12 km at an average speed of 38m/s. Subsequently, the lahar signal evolved to a relatively stationary infrasonic tremor located …

High-Precision U-Pb Ca-Tims Calibration Of Middle Permian To Lower Triassic Sequences, Mass Extinction And Extreme Climate-Change In Eastern Australian Gondwana, I. Metcalfe, J. Crowley, R. S. Nicoll, M. Schmitz

Geosciences Faculty Publications and Presentations

Twenty-eight new high-precision Chemical Abrasion Isotope Dilution Thermal Ionisation Mass Spectrometry U-Pb zircon dates for tuffs in the Sydney and Bowen Basins are reported. Based on these new dates, the Guadalupian-Lopingian/Capitanian-Wuchiapingian boundary is tentatively placed at the level of the Thirroul Sandstone in the lower part of the Illawarra Coal Measures in the Sydney Basin. The Wuchiapingian-Changhsingian boundary is at or close to the Kembla Sandstone horizon in the Illawarra Coal Measures, southern Sydney Basin, in the middle part of the Newcastle Coal Measures in the northern Sydney Basin, and in the middle of the Black Alley Shale in the …

Tracking And Characterization Of Moving Acoustic Sources Using An Infrasound Array At Volcán Santiaguito, Guatemala, Brian R. Terbush

Boise State University Theses and Dissertations

Active volcanic processes produce large amounts of acoustic energy within the infrasound band (0-20 Hz). Infrasound-sensitive microphones are often installed in addition to other forms of volcano monitoring equipment to increase the ability to remotely detect volcanic activity. In this study, an array of microphones was deployed without any additional sensor types for 36 hours at Santiaguito, Guatemala, to test the detection capabilities of a standalone microphone array. Array processing was applied to the recorded data, through frequency-domain beamforming and calculating a Fisher statistic (F). A changing F-threshold value was applied to differentiate between desired detections, or …

Defining Antecedent Topography At Coral Pink Sand Dunes, Kane County, Utah: The Influence Of Structural Controls On Dune-Field Boundary Conditions And Holocene Landscape Evolution, Elizabeth Janna Rozar

Boise State University Theses and Dissertations

Dune fields are transient features that record climate signatures through changes in mobility, morphology, and patterning. Aeolian geomorphologists are increasingly recognizing the important role that pre-existing, antecedent topography plays in controlling boundary conditions that affect changes in dune patterning. However, the dynamic relationship between antecedent topography and climate-sensitive boundary conditions is relatively unexplored. Here, I define antecedent topography for the Coral Pink Sand Dunes in southern Utah and show that structural controls play an important role in shaping antecedent geomorphic conditions of this dune field. I use ground-based terrestrial laser scanning (TLS) to produce a high-resolution digital elevation model (DEM), …

Multi-Component Active Source Rayleigh Wave Analysis, Gabriel Gribler

Boise State University Theses and Dissertations

Determining how a building site will respond to earthquake ground shaking plays a critical role in proper construction practices. One critical constraint on how a site responds is the near surface shear wave seismic velocity distribution. One commonly used method for indirectly estimating shear wave velocities is Multichannel Analysis of Surface Waves (MASW), which utilizes a spread of vertical geophones to measure Rayleigh wave dispersion. With this approach, phase velocity vs. frequency dispersion curve picks can be used to estimate shear wave velocities with depth. I investigate the use of two (vertical and horizontal inline) component seismic signals to record …

Impacts Of Changing Snowmelt Timing On Non-Irrigated Crop Yield, Erin Murray

Boise State University Theses and Dissertations

As climate changes, the final date of spring snowmelt is projected to occur earlier in the year within the western United States. This earlier snowmelt timing may impact crop yield in snow-dominated watersheds by changing the timing of water delivery to agricultural fields. There is considerable uncertainty about how agricultural impacts of snowmelt timing may vary by region, crop type, and practices like irrigation vs. dryland farming. We utilize parametric regression techniques to isolate the magnitude of impact snowmelt timing has had on historical crop yield independently of climate and physiographic variables that also impact yield. To do this, we …

Stable Isotopes Reveal A Disconnect Between Biotic And Abiotic Hydrological Processes In A Seasonally-Dry, Semi-Arid Watershed, Ryan James Mccutcheon

Boise State University Theses and Dissertations

Until recently, it had been thought that humid catchment woody plants transpired primarily mobile soil water that would otherwise flow to streams or recharge groundwater. However, several recent studies have suggested that trees in seasonally-dry humid catchments use primarily tightly-bound, immobile soil water that does not fully mix with new precipitation or participate in translatory flow. McDonnell (2014) called this existence of two, hydrologically-distinct, water pools “the two water worlds hypothesis.” This ecohydrological behavior has important implications for understanding a wide range of catchment processes, including the spatial and temporal variability of evapotranspiration and nutrient cycling, and our abilities to …

Automatic Detection And Denoising Of Signals In Large Geophysical Datasets, Gabriel O. Trisca

Boise State University Theses and Dissertations

To fully understand the complex interactions of various phenomena in the natural world, scientific disciplines such as geology and seismology increasingly rely upon analyzing large amounts of observations. However, data collection is growing at a faster rate than what is currently possible to analyze through traditional approaches. These datasets, supplied by the increasing use of sensors and remote sensing, require specialized computer programs to effectively analyze complex and expansive volumes of data.

Elaborating on existing geophysical data processing approaches for infrasound data collected from an avalanche-prone area, this project proposes new techniques for processing large geophysical datasets. These improved techniques …

Forecasting The Response Of Earth’S Surface To Future Climatic And Land Use Changes: A Review Of Methods And Research Needs, Jennifer L. Pierce, Michael J. Poulos

Geosciences Faculty Publications and Presentations

In the future, Earth will be warmer, precipitation events will be more extreme, global mean sea level will rise, and many arid and semiarid regions will be drier. Human modifications of landscapes will also occur at an accelerated rate as developed areas increase in size and population density. We now have gridded global forecasts, being continually improved, of the climatic and land use changes (C&LUC) that are likely to occur in the coming decades. However, besides a few exceptions, consensus forecasts do not exist for how these C&LUC will likely impact Earth-surface processes and hazards. In some cases, we have …

Laser Vision: Lidar As A Transformative Tool To Advance Critical Zone Science, N. F. Glenn

Geosciences Faculty Publications and Presentations

Observation and quantification of the Earth’s surface is undergoing a revolutionary change due to the increased spatial resolution and extent afforded by light detection and ranging (lidar) technology. As a consequence, lidar-derived information has led to fundamental discoveries within the individual disciplines of geomorphology, hydrology, and ecology. These disciplines form the cornerstones of critical zone (CZ) science, where researchers study how interactions among the geosphere, hydrosphere, and biosphere shape and maintain the “zone of life”, which extends from the top of unweathered bedrock to the top of the vegetation canopy. Fundamental to CZ science is the development of transdisciplinary theories …

Where Were You When The Mountain Blew? Remembering The Eruption Of Mount St Helens, Brittany Brand

Geosciences Faculty Publications and Presentations

May 18, 1980. On that fateful day, Mt St Helens Volcano in Washington exploded violently after two months of intense earthquake activity and intermittent, relatively weak eruptions, causing the worst volcanic disaster in the recorded history of the United States. – US Geological Survey Special Report

Without checking your calendar, can you remember where you were on at 8:30 am April 24, 2015? Some of you might, but more will likely have to think hard to remember. In contrast, if you ask someone who lived in the Pacific Northwest 35 years ago where they were at 8:32 am on May …

Filling The Gap: New Precise Early Cretaceous Radioisotopic Ages From The Andes, Beatriz Aguirre-Urreta, Marina Lescano, Mark D. Schmitz, Maisa Tunik, Andrea Concheyro, Peter F. Rawson, Victor A. Ramos

Geosciences Faculty Publications and Presentations

Two tuffs in the Lower Cretaceous Agrio Formation, Neuquén Basin, provided U–Pb zircon radioisotopic ages of 129.09 ± 0.16 Ma and 127.42 ± 0.15 Ma. Both horizons are well constrained biostratigraphically by ammonites and nannofossils and can be correlated with the ‘standard’ sequence of the Mediterranean Province. The lower horizon is very close to the base of the Upper Hauterivian and the upper horizon to the Hauterivian/Barremian boundary, indicating that the former lies at c. 129.5 Ma and the latter at c. 127 Ma. These new radioisotopic ages fill a gap of over 8 million years in the …

Seismic Imaging To Help Understand And Manage Water Quality In Coastal Bénin, West Africa, Kyle Lindsay, John Bradford, Steve Silliman, Nicaise Yalo, Moussa Boukari

Geosciences Faculty Publications and Presentations

We collected seismic data along 15 transects to characterize the geometry of a coastal aquifer in Bénin, West Africa, that is being contaminated by saltwater. We used standard high-resolution seismic methods to image the upper ∼200 m using a sledgehammer source and a 120-channel recording system. Three transects were processed with an iterative updating flow that includes prestack depth migration, residual moveout analysis, and reflection tomography, and the remaining 12 transects were processed with routine processing flows and poststack time migration. We identified one unconfined aquifer and three confined aquifers separated by reflective confining clay layers. Some transects showed areas …

Vegetative And Climatic Controls On Holocene Wildfire And Erosion Recorded In Alluvial Fans Of The Middle Fork Salmon River, Idaho, Kerry Riley, Jennifer Pierce, Grant A. Meyer

Geosciences Faculty Publications and Presentations

The Middle Fork Salmon River watershed spans high-elevation mixed-conifer forests to lower-elevation shrub-steppe. In recent decades, runoff from severely burned hillslopes has generated large debris flows in steep tributary drainages. These flows incised alluvial fans along the mainstem river, where charcoal-rich debris-flow and sheetflood deposits preserve a record of latest Pleistocene to Holocene fires and geomorphic response. Through deposit sedimentology and ¹⁴C dating of charcoal, we evaluate the processes and timing of fire-related sedimentation and the role of climate and vegetation change. Fire-related deposits compose ~66% of the total measured fan deposit thickness in more densely forested upper basins …

Westward Growth Of Laurentia By Pre–Late Jurassic Terrane Accretion, Eastern Oregon And Western Idaho, United States, Todd A. Lamaskin, Rebecca J. Dorsey, Jeffrey D. Vervoort, Mark D. Schmitz, Kyle P. Tumpane, Nicholas O. Moore

Geosciences Faculty Publications and Presentations

New U-Pb and Sm-Nd data from the Blue Mountains province, eastern Oregon and western Idaho, clarify terrane correlations and regional evolution of the western Laurentian plate margin during Mesozoic time. We report an Early Jurassic age for a red tuff unit at Pittsburg Landing, Idaho, which is 25 m.yr. older than previous Middle Jurassic estimates. In the Coon Hollow Formation at Pittsburg Landing and at the type location on the Snake River, chemical abrasion thermal ionization mass spectrometry U-Pb zircon ages on interbedded tuff and detrital zircon U-Pb maximum depositional ages indicate that deposition spanned ca. 160–150Ma, entirely during Late …