Geophysics and Seismology Commons^™

Detecting Geyser Activity With Infrasound, Jeffrey B. Johnson, J. F. Anderson, R. E. Anthony, M. Sciotto

Geosciences Faculty Publications and Presentations

We monitored geyser activity in the Lower Geyser Basin (LGB) of Yellowstone National Park with dual four-element microphone arrays separated by ~ 600 m. The arrays were independently used to identify incident coherent plane wave energy, then conjoint cross beam back-azimuths from the two arrays were used to precisely locate signal sources. During a week in August 2011 we located repeating infrasound events, peaked in energy between 1 and 10 Hz, originating from at least five independent geothermal features, including the episodically erupting Great Fountain, Fountain and Kaleidoscope Geysers, as well as periodic infrasound from nearby Botryoidal and persistent sound …

The First Second Of Volcanic Eruptions From The Erebus Volcano Lava Lake, Antarctica—Energies, Pressures, Seismology, And Infrasound, A. Gerst, M. Hort, R. C. Aster, J. B. Johnson, P. R. Kyle

Geosciences Faculty Publications and Presentations

[1] We describe a multiparameter experiment at Erebus volcano, Antarctica, employing Doppler radar, video, acoustic, and seismic observations to estimate the detailed energy budget of large (up to 40 m-diameter) bubble bursts from a persistent phonolite lava lake. These explosions are readily studied from the crater rim at ranges of less than 500 m and present an ideal opportunity to constrain the dynamics and mechanism of magmatic bubble bursts that can drive Strombolian and Hawaiian eruptions. We estimate the energy budget of the first second of a typical Erebus explosion as a function of time and energy type. We constrain …

A Latest Carboniferous Warming Spike Recorded By A Fusulinid-Rich Bioherm In Timor Leste: Implications For East Gondwana Deglaciation, Vladimir I. Davydov, David W. Haig, Eujay Mccartain

Geosciences Faculty Publications and Presentations

During the late Paleozoic and early Mesozoic Timor lay in the northern part of the north–south East Gondwana rift system along which the western margin of Australia later developed. Discovery of a latest Gzhelian bioherm in the central highlands of Timor Leste has implications for latest Carboniferous–earliest Permian climate history and deglaciation in basins further south in the rift system.

Limestone outcrop of the Maubisse Formation near the village of Kulau is recognized as a bioherm with a massive lower unit, including reef framework at the base, and a bedded grainstone upper unit. The bioherm developed on a basalt substrate …

Elastic Laboratory Measurements And Modeling Of Saturated Basalts, Ludmila Adam, Thomas Otheim

Geosciences Faculty Publications and Presentations

Understanding the elastic behavior of basalt is important to seismically monitor volcanoes, subsea basalts, and carbon sequestration in basalt. We estimate the elastic properties of basalt samples from the Snake River Plain, Idaho, at ultrasonic (0.8 MHz) and seismic (2–300 Hz) frequencies. To test the sensitivity of seismic waves to the fluid content in the pore structure, measurements are performed at three saturation conditions: saturated with liquid CO₂, water, and dry. When CO₂ replaces water, the P-wave velocity drops, on average, by 10%. Vesicles and cracks, observed in the rock microstructure, control the relaxation of pore-fluid pressures …

Variability Of Pennsylvanian-Permian Carbonate Associations And Implications For Nw Pangea Palaeogeography, East-Central British Columbia, Canada, K. D. Zubin-Stathopoulos, B. Beauchamp, V. I. Davydov, C. M. Henderson

Geosciences Faculty Publications and Presentations

Different stages of Pennsylvanian-Permian carbonate sedimentation in east-central British Columbia record a complex history of changing environments influenced by evolving palaeogeography and climate. Newly recognized tectonically controlled features affected the distribution and variability of carbonate associations, providing new interpretations for this portion of the west coast of Pangea. Both a heterozoan (cool water) and photozoan (warm-water) association were identified on either side of a palaeogeographic high here informally termed “Tipinahokan Peninsula”. Cool water carbonates were located outboard, or to the west of this high, an area influenced by upwelling waters. Inboard of this high, a warm, protected sea developed, here …

Northern Thailand Geothermal Resources And Development: A Review And 2012 Update, Fongsaward Suvagondha Singharajwarapan, Spencer H. Wood, Natthaporn Prommakorn, Lara Owens

Geosciences Faculty Publications and Presentations

Northern Thailand has 16 hot spring systems with surface temperatures near or greater than 80°C with potential for binary plant power generation. Presently only Fang system generates power from wells flowing a total of 8.3 1/s of 116°C water to a 300 kW single module Ormat binary plant. Current production is 150-250 KW, which potentially can be increased by constructing new wells and increasing flow by pumping. Of the other 15 systems, 4 are in national parks and not considered for development. Several of the hot springs systems have silica geothermometry >130°C suggesting significant undeveloped resources exist in northern Thailand. …

Probing Local Wind And Temperature Structure Using Infrasound From Volcan Villarrica (Chile), Jeffrey B. Johnson, J. Anderson, O. Marcillo, S. Arrowsmith

Geosciences Faculty Publications and Presentations

We use the continuous and intense (∼10⁷ W) infrasound produced by Volcan Villarrica (Chile) to invert for the local dynamic wind and temperature structure of the atmosphere. Infrasound arrays deployed in March 2011 at the summit (2826 m) and on the NNW flank (∼8 km distant at 825 m) were used to track infrasound propagation times and signal power. We model an atmosphere with vertically varying temperature and horizontal winds and use propagation times (ranging from 23 to 24 s) to invert for horizontal slowness (2.75–2.94 s/km) and average effective sound speeds (328–346 m/s) for NNW propagating infrasound. The …

Hydrologic Data Assimilation With A Hillslope-Scale-Resolving Model And L Band Radar Observations: Synthetic Experiments With The Ensemble Kalman Filter, Alejandro N. Flores, Rafael L. Bras, Dara Entekhabi

Geosciences Faculty Publications and Presentations

Soil moisture information is critical for applications like landslide susceptibility analysis and military trafficability assessment. Existing technologies cannot observe soil moisture at spatial scales of hillslopes (e.g., 10⁰ to 10² m) and over large areas (e.g., 10² to 10⁵ km²) with sufficiently high temporal coverage (e.g., days). Physics-based hydrologic models can simulate soil moisture at the necessary spatial and temporal scales, albeit with error. We develop and test a data assimilation framework based on the ensemble Kalman filter for constraining uncertain simulated high-resolution soil moisture fields to anticipated remote sensing products, specifically NASA's Soil …

Hillslope Asymmetry Maps Reveal Widespread, Multi-Scale Organization, Michael J. Poulos, Jennifer L. Pierce, Alejandro N. Flores, Shawn G. Benner

Geosciences Faculty Publications and Presentations

Hillslope asymmetry is the condition in which oppositely-facing hillslopes within an area have differing average slope angles, and indicates aspect-related variability in hillslope evolution. As such, the presence, orientation and magnitude of asymmetry may be a useful diagnostic for understanding process dominance. We present a new method for quantifying and mapping the spatial distribution of hillslope asymmetry across large areas. Resulting maps for the American Cordillera of the Western Hemisphere and the western United States reveal that hillslope asymmetry is widespread, with distinct trends at continental to drainage scales. Spatial patterns of asymmetry correlate with latitude along the American Cordillera, …

Sequence Stratigraphy And Onlap History Of The Donets Basin, Ukraine: Insight Into Carboniferous Icehouse Dynamics, J. M. Eros, I. P. Montañez, D. A. Osleger, Vladimir Davydov, T. I. Nemyrovska, V. I. Poletaev, M. V. Zhykalyak

Geosciences Faculty Publications and Presentations

The degree to which Permo-Carboniferous cyclothemic successions archive evidence for long-term variations in ice volume during the Late Paleozoic Ice Age is insufficiently resolved. Here we develop the sequence stratigraphy and onlap-offlap history for a 33-my interval of the Carboniferous using the U-Pb calibrated succession of the Donets Basin, Ukraine, in order to assess the relationship between sea-level, high-latitude changes in glacial extent, and climate. Integrated subsurface and outcrop data permit meter-scale correlation of 242 biostratigraphically constrained limestones and coals, and in turn individual cyclothems, across ~250 km of the Donets Basin. Rapid uniform subsidence and basinwide continuity of marker …

Partitioning Of Rare Earth And High Field Strength Elements Between Titanite And Phonolitic Liquid, Paul H. Olin, John A. Wolff

Geosciences Faculty Publications and Presentations

We present the results of a LA–ICPMS study of titanites and associated glasses from the mixed-magma phonolitic Fasnia Member of the Diego Hernández Formation, Tenerife, Canary Islands. We employ a method of identifying equilibrium mineral–melt pairs from natural samples using REE contents and a linear form of the lattice strain model equation (Blundy and Wood, 1994), where the Young's modulus (E_M) for the 7-fold coordinated site is an output variable. For felsic magmas that contain crystals potentially derived from a variety of environments within the system, this approach is more rigorous than the use of solely textural criteria …

A Simplified Approach For Estimating Soil Carbon And Nitrogen Stocks In Semi-Arid Complex Terrain, Melvin L. Kunkel, Alejandro N. Flores, Toni J. Smith, James P. Mcnamara, Shawn G. Benner

Geosciences Faculty Publications and Presentations

We investigated soil carbon (C) and nitrogen (N) distribution and developed a model, using readily available geospatial data, to predict that distribution across a mountainous, semi-arid, watershed in southwestern Idaho (USA). Soil core samples were collected and analyzed from 133 locations at 6 depths (n=798), revealing that aspect dramatically influences the distribution of C and N, with north-facing slopes exhibiting up to 5 times more C and N than adjacent southfacing aspects. These differences are superimposed upon an elevation (precipitation) gradient, with soil C and N contents increasing by nearly a factor of 10 from the bottom (1100 m elevation) …

Taxonomy, Nomenclature, And Evolution Of The Early Schubertellid Fusulinids, Vladimir I. Davydov

Geosciences Faculty Publications and Presentations

The types of the species belonging to the fusulinid genera Schubertella and Eoschubertella were examined from publications and type collections. Eoschubertella in general possesses all the features of Schubertella and therefore is a junior synonym of the latter. However, the concept of Eoschubertella best describes the genus Schubertina with its type species Schubertina curculi. Schubertina is closely related to the newly established genus Grovesella the concept of which is emended in this paper. Besides Schubertella, Schubertina, and Grovesella, the genera Mesoschubertella, Biwaella are reviewed and three new species, Grovesella nevadensis, Biwaella zhikalyaki, and Biwaella poletaevi, are described. The phylogenetic relationships …

Late Holocene Relationships Among Fire, Climate, And Vegetation In Rangeland Ecosystems Of Southwestern Idaho, Nathan A. Nelson, Jennifer Pierce

Geosciences Faculty Publications and Presentations

Rangelands are characterized by more arid climates than forested regions; therefore, establishing fire histories using traditional methods (e.g. fire-scars from trees or charcoal in lake sediments) is problematic. This study uses radiocarbon dating of charcoal preserved in alluvial fans and stream deposits to reconstruct a record of fire and geomorphic response in rangelands of southwestern Idaho. Samples indicate three primary periods of fire-related activity: 4400 – 4000, 2000 – 1400, and 650-400 cal yr BP. Charcoal macrofossil identification and comparison with other regional climate and fire records indicate this area has likely switched between a "fuel-limited" system (fires limited by …

Stable Isotopes Of Fossil Teeth Corroborate Key General Circulation Model Predictions For The Last Glacial Maximum In North America, Matthew J. Kohn, Moriah Mckay

Geosciences Faculty Publications and Presentations

Oxygen isotope data provide a key test of general circulation models (GCMs) for the Last Glacial Maximum (LGM) in North America, which have otherwise proved difficult to validate. High δ18O pedogenic carbonates in central Wyoming have been interpreted to indicate increased summer precipitation sourced from the Gulf of Mexico. Here we show that tooth enamel δ18O of large mammals, which is strongly correlated with local water and precipitation δ18O, is lower during the LGM in Wyoming, not higher. Similar data from Texas, California, Florida and Arizona indicate higher δ18O values than in the Holocene, which is also predicted by GCMs. …

Carbon Isotope Compositions Of Terrestrial C3 Plants As Indicators Of (Paleo)Ecology And (Paleo)Climate, Matthew J. Kohn

Geosciences Faculty Publications and Presentations

A broad compilation of modern carbon isotope compositions in all C3 plant types shows a monotonic increase in δ¹³C with decreasing mean annual precipitation (MAP) that differs from previous models. Corrections for temperature, altitude, or latitude are smaller than previously estimated. As corrected for altitude, latitude, and the δ¹³C of atmospheric CO₂, these data permit refined interpretation of MAP, paleodiet, and paleoecology of ecosystems dominated by C3 plants, either prior to 7–8 million years ago (Ma), or more recently at mid- to high latitudes. Twenty-nine published paleontological studies suggest preservational or scientific bias toward …

Rare Earth And High Field Strength Element Partitioning Between Iron-Rich Clinopyroxenes And Felsic Liquids, Paul H. Olin, John A. Wolff

Geosciences Faculty Publications and Presentations

Rare earth elements are commonly assumed to substitute only for Ca in clinopyroxene because of the similarity of ionic radii for REE³⁺ and Ca²⁺ in 8-fold coordination. The assumption is valid for Mg-rich clinopyroxenes for which observed mineral/melt partition coefficients are readily predicted by the lattice strain model for substitution onto a single site (e.g. Wood and Blundy, 1997). We show that natural Fe-rich pyroxenes in both silica-undersaturated and -oversaturated magmatic systems deviate from this behavior. Salites (Mg# 48 to 59) in phonolites from Tenerife, ferrohedenbergites (Mg# 14.2 to 16.2) from the rhyolitic Bandelier Tuff, and ferroaugites (Mg# …

Arctic Landscapes In Transition: Responses To Thawing Permafrost, James P. Mcnamara

Geosciences Faculty Publications and Presentations

Observations indicate that over the past several decades, geomorphic processes in the Arctic have been changing or intensifying. Coastal erosion, which currently supplies most of the sediment and carbon to the Arctic Ocean [Rachold et al., 2000], may have doubled since 1955 [Mars and Houseknecht, 2007]. Further inland, expansion of channel networks [Toniolo et al., 2009] and increased river bank erosion [Costard et al., 2007] have been attributed to warming. Lakes, ponds, and wetlands appear to be more dynamic, growing in some areas, shrinking in others, and changing distribution across lowland regions …

Reproducibility Of Soil Moisture Ensembles When Representing Soil Parameter Uncertainty Using A Latin Hypercube-Based Approach With Correlation Control, Alejandro N. Flores, Dara Entekhabi, Rafael L. Bras

Geosciences Faculty Publications and Presentations

Representation of model input uncertainty is critical in ensemble‐based data assimilation. Monte Carlo sampling of model inputs produces uncertainty in the hydrologic state through the model dynamics. Small Monte Carlo ensemble sizes are desirable because of model complexity and dimensionality but potentially lead to sampling errors and correspondingly poor representation of probabilistic structure of the hydrologic state. We compare two techniques to sample soil hydraulic and thermal properties (SHTPs): (1) Latin Hypercube (LH) based sampling with correlation control and (2) random sampling from SHTP marginal distributions. A hydrology model is used to project SHTP uncertainty onto the soil moisture state …

High-Precision U-Pb Zircon Age Calibration Of The Global Carboniferous Time Scale And Milankovitch Band Cyclicity In The Donets Basin, Eastern Ukraine, Vladimir I. Davydov, James L. Crowley, Mark D. Schmitz, Vladislav I. Poletaev

Geosciences Faculty Publications and Presentations

High-precision ID-TIMS U-Pb zircon ages for 12 interstratified tuffs and tonsteins are used to radiometrically calibrate the detailed lithostratigraphic, cyclostratigraphic, and biostratigraphic framework of the Carboniferous Donets Basin of eastern Europe. Chemical abrasion of zircons, use of the internationally calibrated EARTHTIME mixed U-Pb isotope dilution tracer, and improved mass spectrometry guided by detailed error analysis have resulted in an age resolution of

Modeling Soil Depth From Topographic And Land Cover Attributes, Teklu K. Tesfa, David G. Tarboton, David G. Chandler, James P. Mcnamara

Geosciences Faculty Publications and Presentations

Soil depth is an important input parameter in hydrological and ecological modeling. Presently, the soil depth data available in national soil databases (STATSGO and SSURGO) from the Natural Resources Conservation Service are provided as averages within generalized land units (map units). Spatial uncertainty within these units limits their applicability for distributed modeling in complex terrain. This work reports statistical models for prediction of soil depth in a semiarid mountainous watershed that are based upon the relationship between soil depth and topographic and land cover attributes. Soil depth was surveyed by driving a rod into the ground until refusal at locations …

Estimating Debye Parameters From Gpr Reflection Data Using Spectral Ratios, John H. Bradford

Geosciences Faculty Publications and Presentations

In the GPR frequency range, electromagnetic wave attenuation is largely controlled by dielectric relaxation processes. A primary relaxation commonly occurs in the 10 – 100 MHz range for many earth materials in which the GPR signal propagates effectively. This relaxation leads to strong nonlinearity in the frequency dependent attenuation and occurs in a frequency range that is often used for groundwater investigations. This non-linearity complicates data analysis but also may provide additional material property information. I investigate inversion for Debye relaxation parameters directly from GPR reflection data, including increasing the bandwidth of the signal by summing the response from 25 …

Improved Confidence In (U-Th)/He Thermochronology Using The Laser Microprobe: An Example From A Pleistocene Leucogranite, Nanga Parbat, Pakistan, J. W. Boyce, K. V. Hodges, D. King, James L. Crowley, M. Jercinovic, N. Chatterjee, S. A. Bowring, M. Searle

Geosciences Faculty Publications and Presentations

The newly developed laser microprobe (U-Th)/He thermochronometer permits, for the first time, the ability to generate precise (U-Th)/He cooling ages for even very young (Ma) samples with a spatial resolution on the order of tens of micrometers. This makes it possible to test the reproducibility of independent (U-Th)/He age determinations within individual crystals, further increasing the reliability of the method. As an example, we apply it here to a Pleistocene granite from Nanga Parbat, Pakistan, where previous constraints on the thermal history are consistent with rapid exhumation and cooling. Twenty-one (U-Th)/He dates determined on two monazite crystals from a single …

Experimental Evidence Of Non-Linear Dissipation Using Acoustic Micro-Lapses, G. Quiroga-Goode, K. Van Wijk

Geosciences Faculty Publications and Presentations

Non-linear material behaviour is observed experimentally in a laboratory using a new method called Acoustic Micro-Lapses (AML). In this approach, the shooting of two waves is synchronised in a way that the second wave (TW) is to sense the fluctuations in material stiffness induced by the first (PW). The tests include four samples; twenty trials are performed for each sample by increasing time-delays between the waves. The recorded waves are decoupled and compared to determine spectral differences by computing a quantity proportional to the energy difference as function of the increasing time delay (). For a tight sandstone and aluminium …

Models Of Garnet Differential Geochronology, Matthew J. Kohn

Geosciences Faculty Publications and Presentations

Rayleigh distillation models are developed to describe theoretical growth zoning of Lu, Hf, Rb, Sr, Sm and Nd in typical garnet crystals from metapelites and metabasites. Effects of diffusion limited transport within the matrix and intracrystalline diffusion are also considered qualitatively. Theoretical zoning profiles show strong depletions of Lu in garnet rims compared to cores, but virtually invariant Hf, Rb, Sr, Sm, and Nd profiles, generally consistent with natural profiles for Lu and Hf and previously published models. Theoretical isochron diagrams for Lu-Hf exhibit distinctive arcuate distributions and high MSWD’s consistent both with Himalayan data, and with expectations that garnet …

Correction Of Electronic Record For Weighing Bucket Precipitation Gauge Measurements, Anurag Nayak, David G. Chandler, Danny Marks, James P. Mcnamara, Mark Seyfried

Geosciences Faculty Publications and Presentations

Electronic sensors generate valuable streams of forcing and validation data for hydrologic models but are often subject to noise which must be removed as part of model input and testing database development. We developed an automated precipitation correction program (APCP) for weighing bucket precipitation gauge records, which are subject to several types of mechanical and electronic noise and discontinuities, including gauge maintenance, missing data, wind vibration, and sensor drift. Corrected cumulative water year precipitation from APCP did not exhibit an error bias and matched measured water year total precipitation within 2.1% for 58 station years tested. Removal of low-amplitude periodic …

Assessing Inheritance Of Zircon And Monazite In Granitic Rocks From The Monashee Complex, Canadian Cordillera, James Crowley, R. L. Brown, F. Gervais, H. D. Gibson

Geosciences Faculty Publications and Presentations

Zircon and monazite from granitic sheets and dikes in the Monashee complex, Canadian Cordillera, were investigated to determine whether igneous crystallization occurred at 1.9 Ga or 50 Ma with 1.9 Ga inherited zircon and monazite. Four of the five samples are weakly deformed to undeformed, despite occurring in a gneiss dome at the structurally deepest exposed level of the orogen that elsewhere was strongly deformed and partly melted at 50 Ma. Based on U-(Th)-Pb dates from zircon and monazite, field relationships, and mineral composition and zoning, we conclude that the granitic rocks crystallized at 1.9 Ga and were metamorphosed at …

Floodplain Deposits, Channel Changes And Riverbank Stratigraphy Of The Mekong River Area At The 14th-Century City Of Chiang Saen, Northern Thailand., Spencer H. Wood, Alan D. Ziegler, Tharaporn Bundarnsin

Geosciences Faculty Publications and Presentations

Riverbank stratigraphy and paleochannel patterns of the Mekong River at Chiang Saen provide a geoarchaeological framework to explore for evidence of Neolithic, Bronze-age, AD 5th Century Yonok and AD 14-16th Century Lan Na Cultures. Typical bank stratigraphy charted on the Thailand side is imbricate cobble gravel overlain by 5-10 m of reddish-brown sandy silt. The silt section is composed chiefly of ½ to 2-m thick layers of massive silt without paleosols interpreted as near-channel floodplain and gently-inclined levee deposits laid down by episodic, infrequent, large floods. The surface soil is dark-brown clay loam (La Na time. Brick ruins of 14-16th …

Hyporheic Exchange And Water Chemistry Of Two Arctic Tundra Streams Of Contrasting Geomorphology, Morgan J. Greenwald, William B. Bowden, Michael N. Gooseff, Jay P. Zarnetske, James P. Mcnamara, John H. Bradford, Troy R. Brosten

Geosciences Faculty Publications and Presentations

The North Slope of Alaska’s Brooks Range is underlain by continuous permafrost, but an active layer of thawed sediments develops at the tundra surface and beneath streambeds during the summer, facilitating hyporheic exchange. Our goal was to understand how active layer extent and stream geomorphology influence hyporheic exchange and nutrient chemistry. We studied two arctic tundra streams of contrasting geomorphology: a high-gradient, alluvial stream with riffle-pool sequences and a low-gradient, peat-bottomed stream with large deep pools connected by deep runs. Hyporheic exchange occurred to ~50 cm beneath the alluvial streambed and to only ~15 cm beneath the peat streambed. The …

Comparison Of Instantaneous And Constant-Rate Stream Tracer Experiments Through Parametric Analysis Of Residence Time Distributions, Robert A. Payn, Michael N. Gooseff, David A. Benson, Olaf A. Cirpka, Jay P. Zarnetske, W. Breck Bowden, James P. Mcnamara, John H. Bradford

Geosciences Faculty Publications and Presentations

Artificial tracers are frequently employed to characterize solute residence times in stream systems and infer the nature of water retention. When the duration of tracer application is different between experiments, tracer breakthrough curves at downstream locations are difficult to compare directly. We explore methods for deriving stream solute residence time distributions (RTD) from tracer test data, allowing direct, non-parametric comparison of results from experiments of different durations. Paired short- and long-duration field experiments were performed using instantaneous and constant-rate tracer releases, respectively. The experiments were conducted in two study reaches that were morphologically distinct in channel structure and substrate size. …