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A Preliminary Assessment Of Water Partitioning And Ecohydrological Coupling In Northern Headwaters Using Stable Isotopes And Conceptual Runoff Models, James P. Mcnamara Dec 2015

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 …


Infrasound From Volcanic Rockfalls, Jeffrey B. Johnson, Timothy J. Ronan Dec 2015

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 …


Natural Degradation Of Earthworks, Trenches, Walls And Moats, Northern Thailand, Spencer H. Wood, Layle R. Wood, Alan D. Ziegler Dec 2015

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 …


Streambed And Water Profile Response To In-Channel Restoration Structures In A Laboratory Meandering Stream, Bangshuai Han, Hong-Hanh Chu, Theodore A. Endreny Nov 2015

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 …


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 Oct 2015

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 …


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 Oct 2015

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 Mw 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 …


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 Sep 2015

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 Sep 2015

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 Aug 2015

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 …


Tracking And Characterization Of Moving Acoustic Sources Using An Infrasound Array At Volcán Santiaguito, Guatemala, Brian R. Terbush Aug 2015

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 Aug 2015

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 Aug 2015

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 …


Stable Isotopes Reveal A Disconnect Between Biotic And Abiotic Hydrological Processes In A Seasonally-Dry, Semi-Arid Watershed, Ryan James Mccutcheon Aug 2015

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 …


Impacts Of Changing Snowmelt Timing On Non-Irrigated Crop Yield, Erin Murray Aug 2015

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 …


Automatic Detection And Denoising Of Signals In Large Geophysical Datasets, Gabriel O. Trisca Aug 2015

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 …


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 Aug 2015

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 …


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 Jul 2015

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 Jun 2015

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 May 2015

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 …


Seismic Imaging To Constrain Groundwater Models For A Better Understanding And Management Of Water Quality In Coastal Benin, West Africa: A Saltwater Intrusion Problem, Kyle Michael Lindsay May 2015

Seismic Imaging To Constrain Groundwater Models For A Better Understanding And Management Of Water Quality In Coastal Benin, West Africa: A Saltwater Intrusion Problem, Kyle Michael Lindsay

Boise State University Theses and Dissertations

The coastal city of Cotonou in Bénin, West Africa, is a large population center that is facing a serious threat to the sustainability of its fresh water supply. Cotonou relies on groundwater derived from the Godomey aquifer for its domestic water supply. The aquifer is undergoing saltwater intrusion due to an increase in pumping to accommodate a growth in population. Hence, there is substantial interest in better characterizing the groundwater system for the purpose of determining appropriate management strategies to ensure sustainability of this freshwater resource.

I collected seismic reflection data along 15 transects to characterize the geometry of the …


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 May 2015

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 …


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 May 2015

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 May 2015

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 …


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 May 2015

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 …


Chile’S Calbuco Volcano Erupts Without Warning. What Can We Expect Next?, Brittany Brand Apr 2015

Chile’S Calbuco Volcano Erupts Without Warning. What Can We Expect Next?, Brittany Brand

Geosciences Faculty Publications and Presentations

Around 5:00 pm local time on April 22, scientists at Southern Andean Volcano Observatory in Chile began picking up volcanic earthquakes at the Calbuco volcano. A disturbingly short 60 minutes later, the volcano was in full eruption, producing an impressive column of ash extending to more than 49,000 feet into the sky. Ash primarily drifted north and northeast of the volcano, covering towns below in a layer of fine ash. Observatory scientists quickly called for an evacuation zone of 12.5 miles.


Zircon Chemistry In A Gabbro Pluton At House Mountain, Idaho, Danielle Terhaar, Mark Schmitz Apr 2015

Zircon Chemistry In A Gabbro Pluton At House Mountain, Idaho, Danielle Terhaar, Mark Schmitz

College of Arts and Sciences Presentations

An Eocene (ca 45 million year old) gabbro pluton near House Mountain in southwest Idaho provides an opportunity to explore how the conditions of crystallization are recorded in zircon chemistry. Zircon is a zirconium silicate mineral present in trace amounts in magmas, which is capable of incorporating large, highly charged elements (e.g. transition metals, actinides, lanthanides) that do not easily substitute into other minerals. Variations in these elements can be used to track magma evolution. For example, the titanium concentration is related to the temperature at which zircon crystallizes from the magma; rare earth elements (REE) and the relative …


Reconstructing The Geologic History Of The House Mountain Metamorphic Complex (Southern Idaho) Through Zircon Age And Geochemical Analysis, Eli Andersen, Mark Schmitz Apr 2015

Reconstructing The Geologic History Of The House Mountain Metamorphic Complex (Southern Idaho) Through Zircon Age And Geochemical Analysis, Eli Andersen, Mark Schmitz

College of Arts and Sciences Presentations

Zircons from quartzo-feldspathic gneiss within the Precambrian (>725 Ma) siliciclastics of the House Mountain Metamorphic Complex of southwestern Idaho were studied to determine its origin and evolution. Cathodoluminescence imaging of internal zoning due to growth and recrystallization of zircon, along with laser ablation inductively coupled plasma mass spectrometer (LA-ICPMS) analysis of these zircons, reveal a complex history of metamorphism at House Mountain. Primary igneous crystallization in the orthogneiss occurred near 130 Ma. Convoluted regions of the zircons have ages ranging from 130 to 85 Ma. These younger ages are hypothesized to be related to lead loss and new crystal …


Focused Exhumation Along Megathrust Splay Faults In Prince William Sound, Alaska, Peter J. Haeussler, Phillip A. Armstrong, Lee M. Liberty, Kelly M. Ferguson, Shaun P. Finn, Jeanette C. Arkle, Thomas L. Pratt Apr 2015

Focused Exhumation Along Megathrust Splay Faults In Prince William Sound, Alaska, Peter J. Haeussler, Phillip A. Armstrong, Lee M. Liberty, Kelly M. Ferguson, Shaun P. Finn, Jeanette C. Arkle, Thomas L. Pratt

Geosciences Faculty Publications and Presentations

Megathrust splay faults are a common feature of accretionary prisms and can be important for generating tsunamis during some subduction zone earthquakes. Here we provide new evidence from Alaska that megathrust splay faults have been conduits for focused exhumation in the last 5 Ma. In most of central Prince William Sound, published and new low-temperature thermochronology data indicate little to no permanent rock uplift over tens of thousands of earthquake cycles. However, in southern Prince William Sound on Montague Island, apatite (U–Th)/He ages are as young as 1.1 Ma indicating focused and rapid rock uplift. Montague Island lies in the …


Dynamical Precipitation Downscaling For Hydrologic Applications Using Wrf 4d-Var Data Assimilation: Implications For Gpm Era, Liao-Fan Lin, Ardeshir M. Ebtehaj, Rafael L. Bras, Alejandro N. Flores, Jingfeng Wang Apr 2015

Dynamical Precipitation Downscaling For Hydrologic Applications Using Wrf 4d-Var Data Assimilation: Implications For Gpm Era, Liao-Fan Lin, Ardeshir M. Ebtehaj, Rafael L. Bras, Alejandro N. Flores, Jingfeng Wang

Geosciences Faculty Publications and Presentations

The objective of this study is to develop a framework for dynamically downscaling spaceborne precipitation products using the Weather Research and Forecasting (WRF) Model with four-dimensional variational data assimilation (4D-Var). Numerical experiments have been conducted to 1) understand the sensitivity of precipitation downscaling through point-scale precipitation data assimilation and 2) investigate the impact of seasonality and associated changes in precipitation-generating mechanisms on the quality of spatiotemporal downscaling of precipitation. The point-scale experiment suggests that assimilating precipitation can significantly affect the precipitation analysis, forecast, and downscaling. Because of occasional overestimation or underestimation of small-scale summertime precipitation extremes, the numerical experiments presented …


A Meta-Analysis Of Soil Biodiversity Impacts On The Carbon Cycle, M.-A. De Graaff, J. Adkins, P. Kardol, H. L. Throop Mar 2015

A Meta-Analysis Of Soil Biodiversity Impacts On The Carbon Cycle, M.-A. De Graaff, J. Adkins, P. Kardol, H. L. Throop

Biology Faculty Publications and Presentations

Loss of biodiversity impacts ecosystem functions, such as carbon (C) cycling. Soils are the largest terrestrial C reservoir, containing more C globally than the biotic and atmospheric pools together. As such, soil C cycling, and the processes controlling it, has the potential to affect atmospheric CO2 concentrations and subsequent climate change. Despite the growing evidence of links between plant diversity and soil C cycling, there is a dearth of information on whether similar relationships exist between soil biodiversity and C cycling. This knowledge gap occurs even though there has been increased recognition that soil communities display high levels of …