Geophysics and Seismology Commons^™

T414, Pingxin Xia, Longtan Shao, Wen Deng

Stress-State Dependency of the Deformation Ratio of Quasi-Elastic Granular Soils under Cyclic Loading -- Raw Data

‘T’ series spreadsheets are the raw data of all tests. (The data in this series are overall stress and strain information).

Supporting information

Strain Field_Y, Pingxin Xia, Longtan Shao, Wen Deng

Stress-State Dependency of the Deformation Ratio of Quasi-Elastic Granular Soils under Cyclic Loading -- Raw Data

‘Strain field_y’ spreadsheet is the axial strain information of all the nodes. Data format is the same as ‘Strain field_x’

Supporting information

Pf7, Pingxin Xia, Longtan Shao, Wen Deng

Stress-State Dependency of the Deformation Ratio of Quasi-Elastic Granular Soils under Cyclic Loading -- Raw Data

‘PS’ and ‘PF’ spreadsheets are the data of the prediction and calibration tests. (The data in this series are overall stress and strain information).

Supporting information

Ps Series, Pingxin Xia, Longtan Shao, Wen Deng

Stress-State Dependency of the Deformation Ratio of Quasi-Elastic Granular Soils under Cyclic Loading -- Raw Data

‘PS’ and ‘PF’ spreadsheets are the data of the prediction and calibration tests. (The data in this series are overall stress and strain information).

Supporting information

T111, Pingxin Xia, Longtan Shao, Wen Deng

Stress-State Dependency of the Deformation Ratio of Quasi-Elastic Granular Soils under Cyclic Loading -- Raw Data

‘T’ series spreadsheets are the raw data of all tests. (The data in this series are overall stress and strain information).

Supporting information

T124, Pingxin Xia, Longtan Shao, Wen Deng

Stress-State Dependency of the Deformation Ratio of Quasi-Elastic Granular Soils under Cyclic Loading -- Raw Data

‘T’ series spreadsheets are the raw data of all tests. (The data in this series are overall stress and strain information).

Supporting information

T214, Pingxin Xia, Longtan Shao, Wen Deng

Stress-State Dependency of the Deformation Ratio of Quasi-Elastic Granular Soils under Cyclic Loading -- Raw Data

‘T’ series spreadsheets are the raw data of all tests. (The data in this series are overall stress and strain information).

Supporting information

High-Precision U-Pb Age Constraints On The Permian Floral Turnovers, Paleoclimate Change, And Tectonics Of The North China Block, Qiong Wu, Jahandar Ramezani, Hua Zhang, Jun Wang, Wan Yang, For Full List Of Authors, See Publisher's Website.

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The Permian marine-terrestrial system of the North China block provides an exceptional window into the evolution of northern temperate ecosystems during the critical transition from icehouse to greenhouse following the late Paleozoic ice age (LPIA). Despite many studies on its rich hydrocarbon reserves and climate-sensitive fossil flora, uncertain temporal constraints and correlations have hampered a thorough understanding of the records of geologic, biologic, and climatic change from the North China block. We present a new chronostratigraphy based on high-precision U-Pb chemical abrasion-isotope dilution-thermal ionization mass spectrometry (CA-ID-TIMS) geochronology of tuffs from a near-complete latest Carboniferous-Permian succession in North China. The …

Diatoms In Hyporheic Sediments Trace Organic Matter Retention And Processing In The Mcmurdo Dry Valleys, Antarctica, Anna J. Bergstrom

Geosciences Faculty Publications and Presentations

In low‐nutrient streams in cold and arid ecosystems, the spiraling of autochthonous particulate organic matter (POM) may provide important nutrient subsidies downstream. Because of its lability and the spatial heterogeneity of processing in hyporheic sediments, the downstream transport and fate of autochthonous POM can be difficult to trace. In Antarctic McMurdo Dry Valley (MDV) streams, any POM retained in the hyporheic zone is expected to be derived from surface microbial mats that contain diatoms with long‐lasting silica frustules. We tested whether diatom frustules can be used to trace the retention of autochthonous POM in the hyporheic zone and whether certain …

Resonant Frequency Derived From The Rayleigh‐Wave Dispersion Image: The High‐Impedance Boundary Problem, Lee M. Liberty, James St. Clair, T. Dylan Mikesell, William D. Schermerhorn

Geosciences Faculty Publications and Presentations

We present a simple and automated approach to estimate primary site‐response resonance, layer thickness, and shear‐wave velocity directly from a dispersion image for a layer over half‐space problem. We demonstrate this for high‐impedance boundary conditions that lie in the upper tens of meters. Our approach eliminates the need for time‐consuming dispersion curve picking and 1D shear‐wave velocity inversion for large data volumes that can capture velocity structure in profile. We highlight important relationships between dispersion characteristics and resonance parameters through synthetic modeling and field data acquired over Atlantic Coastal Plain sediments. In this environment, shallow soil conditions are critical to …

Microstructural Characteristics Of Deformed Quartz Under Non-Steady-State Conditions, Hamidreza Soleymani

Dissertations, Theses, and Capstone Projects

Because of the long timescale of many geological processes (millions of years), it has been traditionally assumed that the existing forces acting on the rocks at deep crustal levels are in equilibrium (i.e., steady-state). An alternative assumption, however, suggests that rocks in the lower crust and upper mantle are continuously evolving and exchanging energy at various time scales. Under the latter assumption (i.e., non-steady-state), certain geologic systems may never attain equilibrium regardless of the length and the time scale of operating geologic events. These two “endpoint” assumptions suggest there is a wide range of geologically reasonable conditions under which rocks …

Stick-Slip Tremor Beneath An Alpine Glacier, J. Umlauft, F. Lindner, P. Roux, T. D. Mikesell, M. M. Haney, M. Korn, F. T. Walter

Geosciences Faculty Publications and Presentations

Sliding of glacial ice over its base is typically described by a frictionless or slowly deforming bed. This view is challenged by recent seismic observations of stick-slip motion at the icebed interface. We revisit a high-frequency (20–35 Hz) harmonic tremor recorded on Gornergletscher, Switzerland. In contrast to previous interpretation in terms of glaciohydraulic tremor, we present evidence for superimposed stick-slip episodes as tremor sources: we locate the tremor source with matched field processing polarity optimization, which allows for azimuthal polarity patterns associated with nonisotropic moment tensors and yields a tremor source clustering near the glacier bed. Our analysis confirms an …

Spatial Patterns And Drivers Of Nonperennial Flow Regimes In The Contiguous United States, Kendra Kaiser

Geosciences Faculty Publications and Presentations

Over half of global rivers and streams lack perennial flow, and understanding the distribution and drivers of their flow regimes is critical for understanding their hydrologic, biogeochemical, and ecological functions. We analyzed nonperennial flow regimes using 540 U.S. Geological Survey watersheds across the contiguous United States from 1979 to 2018. Multivariate analyses revealed regional differences in no-flow fraction, date of first no flow, and duration of the dry-down period, with further divergence between natural and human-altered watersheds. Aridity was a primary driver of no-flow metrics at the continental scale, while unique combinations of climatic, physiographic and anthropogenic drivers emerged at …

Towards Advancing The Earthquake Forecasting By Machine Learning Of Satellite Data, Pan Xiong, Lei Tong, Kun Zhang, Xuhui Shen, Roberto Battiston, Dimitar Ouzounov, Roberto Iuppa, Danny Crookes, Cheng Long, Huyui Zhou

Mathematics, Physics, and Computer Science Faculty Articles and Research

Earthquakes have become one of the leading causes of death from natural hazards in the last fifty years. Continuous efforts have been made to understand the physical characteristics of earthquakes and the interaction between the physical hazards and the environments so that appropriate warnings may be generated before earthquakes strike. However, earthquake forecasting is not trivial at all. Reliable forecastings should include the analysis and the signals indicating the coming of a significant quake. Unfortunately, these signals are rarely evident before earthquakes occur, and therefore it is challenging to detect such precursors in seismic analysis. Among the available technologies for …

Seismicity And Pn Velocity Structure Of Central West Antarctica, Erica M. Lucas, Andrew A. Nyblade, Andrew J. Lloyd, Richard C. Aster, Douglas A. Wiens, John Paul O'Donnell, Graham W. Stuart, Terry J. Wilson, Ian W. D. Dalziel, J. Paul Winberry, Audrey D. Huerta

Geological Sciences Faculty Scholarship

We have located 117 previously undetected seismic events mainly occurring between 2015 and 2017 that originated from glacial, tectonic, and volcanic processes in central West Antarctica using data recorded on Polar Earth Observing Network (POLENET/ANET) and UK Antarctic Network (UKANET) seismic stations. The seismic events, with local magnitudes (M_L) ranging from 1.1 to 3.5, are predominantly clustered in four geographic regions; the Ellsworth Mountains, Thwaites Glacier, Pine Island Glacier, and Mount Takahe. Eighteen of the events are in the Ellsworth Mountains and can be attributed to a mixture of glacial and tectonic processes. The largest event noted …

Unsteady-State Contact Angle Hysteresis During Droplet Oscillation In Capillary Pores: Theoretical Model And Vof Simulation -- Data, Chao Zeng, Wen Deng, Lichun Wang

Unsteady-State Contact Angle Hysteresis during Droplet Oscillation in Capillary Pores: Theoretical Model and VOF Simulation -- Data

Spreadsheet - Data of Figures 2 through 11.

Supporting information

The Impact Of Initial Snow Conditions On The Numerical Weather Simulation Of A Northern Rockies Atmospheric River, William Rudisill, Alejandro Flores, James Mcnamara

Geosciences Faculty Publications and Presentations

Snow’s thermal and radiative properties strongly impact the land surface energy balance and thus the atmosphere above it. Land surface snow information is poorly known in mountainous regions. Few studies have examined the impact of initial land surface snow conditions in high-resolution, convection-permitting numerical weather prediction models during the midlatitude cool season. The extent to which land surface snow influences atmospheric energy transport and subsequent surface meteorological states is tested using a high-resolution (1 km) configuration of the Weather Research and Forecasting (WRF) Model, for both calm conditions and weather characteristic of a warm late March atmospheric river. A set …

Stable Isotopes Of Water Reveal Differences In Plant – Soil Water Relationships Across Northern Environments, Matthew J. Kohn, James P. Mcnamara

Geosciences Faculty Publications and Presentations

We compared stable isotopes of water in plant stem (xylem) water and soil collected over a complete growing season from five well‐known long‐term study sites in northern/cold regions. These spanned a decreasing temperature gradient from Bruntland Burn (Scotland), Dorset (Canadian Shield), Dry Creek (USA), Krycklan (Sweden), to Wolf Creek (northern Canada). Xylem water was isotopically depleted compared to soil waters, most notably for deuterium. The degree to which potential soil water sources could explain the isotopic composition of xylem water was assessed quantitatively using overlapping polygons to enclose respective data sets when plotted in dual isotope space. At most sites …

Characterizing The Geomagnetic Field At High Southern Latitudes: Evidence From The Antarctic Peninsula, Joseph Biasi, Joseph Kirschvink, Roger Fu

Other Staff Materials

Due to a dearth of data from high-latitude paleomagnetic sites, it is not currently clear if the geocentric axial dipole (GAD) hypothesis accurately describes the long-term behavior of the geomagnetic field at high latitudes. Here we present new paleomagnetic and paleointensity data from the James Ross Island (JRI) volcanic group, located on the Antarctic Peninsula. This data set addresses a notable lack of data from the 60°–70°S latitude bin and includes 251 samples from 31 sites, spanning 0.99–6.8 Ma in age. We also include positive fold, conglomerate, and baked contact tests. Paleointensity data from three methods (Thellier- Thellier, pseudo-Thellier, and …

Designing Computer Applications To Model Geophysical Data For Siting Wells In Developing Countries, Aj Vrieland, Victor T. Norman

Summer Research

In some parts of the world, clean water is hard to find, and wells can be one of the best options available. However, creating a well is a big investment, so finding the best place to site the well is important. Commercial well siting software is prohibitively expensive for many development organizations, costing tens of thousands of dollars. Our open-source software duplicates some functionality of commercial software, but with none of the expense. This summer our project focused on software implementing two geophysical models, resistivity and seismic refraction.