Geophysics and Seismology Commons^™

Seasonality Of Solute Flux And Water Source Chemistry In A Coastal Glacierized Watershed Undergoing Rapid Change: Wolverine Glacier Watershed, Alaska, Anna Bergstrom, Joshua C. Koch, Shad O'Neel, Emily Baker

Geosciences Faculty Publications and Presentations

As glaciers around the world rapidly lose mass, the tight coupling between glaciers and downstream ecosystems is resulting in widespread impacts on global hydrologic and biogeochemical cycling. However, a range of challenges make it difficult to conduct research in glacierized systems, and our knowledge of seasonally changing hydrologic processes and solute sources and signatures is limited. This in turn hampers our ability to make predictions on solute composition and flux. We conducted a broad water sampling campaign in order to understand the present-day partitioning of water sources and associated solutes in Alaska's Wolverine Glacier watershed. We established a relationship between …

Automated Detection Of Marine Glacier Calving Fronts Using The 2-D Wavelet Transform Modulus Maxima Segmentation Method, Julia Liu, Ellyn M. Enderlin, Hans-Peter Marshall, Andre Khalil

Geosciences Faculty Publications and Presentations

Changes in the calving front position of marine-terminating glaciers strongly influence the mass balance of glaciers, ice caps, and ice sheets. At present, quantification of frontal position change primarily relies on time-consuming and subjective manual mapping techniques, limiting our ability to understand changes to glacier calving fronts. Here we describe a newly developed automated method of mapping glacier calving fronts in satellite imagery using observations from a representative sample of Greenland’s peripheral marine-terminating glaciers. Our method is adapted from the 2-D wavelet transform modulus maxima (WTMM) segmentation method, which has been used previously for image segmentation in biomedical and other …

Spatiotemporal Variations In Liquid Water Content In A Seasonal Snowpack: Implications For Radar Remote Sensing, Randall Bonnell, Daniel Mcgrath, Keith Williams, Ryan Webb, Steven R. Fassnacht, Hans-Peter Marshall

Geosciences Faculty Publications and Presentations

Radar instruments have been widely used to measure snow water equivalent (SWE) and Interferometric Synthetic Aperture Radar is a promising approach for doing so from spaceborne platforms. Electromagnetic waves propagate through the snowpack at a velocity determined by its dielectric permittivity. Velocity estimates are a significant source of uncertainty in radar SWE retrievals, especially in wet snow. In dry snow, velocity can be calculated from relations between permittivity and snow density. However, wet snow velocity is a function of both snow density and liquid water content (LWC); the latter exhibits high spatiotemporal variability, there is no standard observation method, and …

In Situ Determination Of Dry And Wet Snow Permittivity: Improving Equations For Low Frequency Radar Applications, Ryan Webb, Adrian Marziliano, Daniel Mcgrath, Randall Bonnell, Tate G. Meehan, Carrie Vuyovich, Hans-Peter Marshall

Geosciences Faculty Publications and Presentations

Extensive efforts have been made to observe the accumulation and melting of seasonal snow. However, making accurate observations of snow water equivalent (SWE) at global scales is challenging. Active radar systems show promise, provided the dielectric properties of the snowpack are accurately constrained. The dielectric constant (k) determines the velocity of a radar wave through snow, which is a critical component of time-of-flight radar techniques such as ground penetrating radar and interferometric synthetic aperture radar (InSAR). However, equations used to estimate k have been validated only for specific conditions with limited in situ validation for seasonal snow applications. …

North Dakota Is A Great Place For Ccus, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about carbon capture, utilization, and storage (CCUS) and how North Dakota is optimal for CCUS. North Dakota has the right geological and regulatory environments for safe, permanent storage of CO₂.

Acoustic/Gravity Wave Phenomena In Wide-Field Imaging: From Data Analysis To A Modeling Framework For Observability In The Mlt Region And Beyond, Jaime Aguilar Guerrero

Doctoral Dissertations and Master's Theses

Acoustic waves, gravity waves, and larger-scale tidal and planetary waves are significant drivers of the atmosphere’s dynamics and of the local and global circulation that have direct and indirect impacts on our weather and climate. Their measurements and characterization are fundamental challenges in Aeronomy that require a wide range of instrumentation with distinct operational principles. Most measurements share the common features of integrating optical emissions or effects on radio waves through deep layers of the atmosphere. The geometry of these integrations create line-of-sight effects that must be understood, described, and accounted for to properly present the measured data in traditional …

Apportioning Deformation Among Depth Intervals In An Aquifer System Using Insar And Head Data, Ryan G. Smith, Hossein Hashemi, Jingyi Chen, Rosemary Knight

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Land surface subsidence due to excessive groundwater pumping is an increasing concern in California, USA. Interferometric Synthetic Aperture Radar (InSAR) is a remote sensing technique for measuring centimeter-to-millimeter surface deformation at 10-100 m spatial resolution. Here, a data-driven approach that attributes deformation to individual depth intervals within an aquifer system by integrating head data acquired from each of three screened intervals in a monitoring well with InSAR surface deformation measurements was developed. The study area was the Colusa Basin in northern Central Valley. To reconstruct the surface deformation history over the study area, 13 ALOS-PALSAR scenes acquired between 2006 and …

Three-Dimensional Intrusion Geometries In The Monogenetic San Rafael (Utah) Sub-Volcanic Field Revealed By Nonlinear Inversion Of Magnetic Anomaly Data, Troy A. Berkey

USF Tampa Graduate Theses and Dissertations

Distributed volcanic fields are common on Earth and nearby planetary bodies. Unlike their central-vent counterparts, these volcanic centers are comprised of many individual basaltic magmatic dikes, which are often only expressed at the surface in the form of vents, domes, and lava flows. In situ imaging of the shallow (<1 km) subsurface can reveal important details about the 3D geometry of fissure systems that feed distributed eruptive centers, with implications for the nature of these eruptions: their mass flow rates, explosivity, durations, and volcanotectonic interaction. Luckily, dikes, sills, conduits and related near-surface structures tend to carry high remnant magnetizations, creating magnetic anomalies at the surface where sufficient magnetic contrast exists with the host rocks they intrude. In the San Rafael Sub-volcanic field (SRSVF), basaltic dikes intrude fractured and horizontally bedded Jurassic sandstones, now eroded to a depth of about 800 m beneath the paleo-surface. Detailed mapping and profiles with a Cs-vapor magnetometer reveal far more complex anomalies than can be attributed to simple planar dikes, including: sills, buds, and domes. We image these geometries using MagCube-parallel, an open-source nonlinear inversion code we developed that models complex geometry with multiple (<= 1,000) vertical-sided prisms. I show one normally polarized fissure system to include along strike: An ~3-14 m thick, ~50 m wide dome-like feature or laccolith at depths of ~9-20 m, a roughly vertical conduit ~15 m thick, ~36-50 m wide, at ~1-16 m depth near the center of the mapped fissure-like system, and a ~8-48 m. wide dike at ~2-17 m depth that is <1-6 m thick, with reducing magnitude northward. While model depth and thickness vary with magnetization contrast, the main geometric relationships do not. Magnetic mapping of a nearby fissure reveals the same types of structures. The implication of these structures is that the small-volume fissure eruptions were likely pulsatory, with episodes of horizontal intrusion of sills, and sufficient time to develop gravitational instabilities.

Slow Slip Events And The Earthquake Cycle, Nicholas K. Voss

USF Tampa Graduate Theses and Dissertations

Slow Slip Events (SSEs) represent a new type of strain release along faults, which have onlybeen recognized as a global phenomena with the growth of precision space-borne geodetic techniques. These events represent an important part of the strain budget on faults, sometimes bounding the area of co-seismic release and perhaps limiting the amount of seismic energy release. SSEs have also been suggested to proceed large megathrust earthquakes including the great 2011 Tohoku and 2015 Iquique earthquakes. I document a series of SSE along the Nicoya Peninsula in Costa Rica. These events take place both before and after the 2012 M7.6 …

Tracking Secondary Lahar Flow Paths And Characterizing Pulses And Surges Using Infrasound Array Networks At Volcán De Fuego, Guatemala, Ashley R. Bosa, Jeffrey B. Johnson, Silvio De Angelis, John J. Lyons, Amilcar Roca, Jacob F. Anderson, Amando Pineda

Geosciences Faculty Publications and Presentations

Lahars are one of the greatest hazards at many volcanoes, including Volcán de Fuego (Guatemala). On 1 December 2018 at 8:00 pm local Guatemala time (~2:06:00 UTC), an hour-long lahar event was detected at Volcán de Fuego by two permanent seismo-acoustic stations along the Las Lajas drainage on the southeast side. To establish the timing, duration, and speed of the lahar, infrasound array records were examined to identify both the source direction(s) and the correlated energy fluctuations at the two stations. Co-located seismic and acoustic signals were also examined, which indicated at least five distinct energy pulses within the lahar …

Timescales Of Magma Transport In The Columbia River Flood Basalts, Determined By Paleomagnetic Data, Joseph Biasi, Leif Karlstrom

Other Staff Materials

Flood basalts represent major events in Earth History, in part because they are linked to large climate perturbations and mass extinctions. However, the durations of individual flood basalt eruptions, which directly impact potential environmental crises, are poorly constrained. Here we use a combination of paleomagnetic data and thermal modeling to create a magnetic geothermometer (MGT) that can constrain the active transport lifetime of magmatic conduits and intrusions. We apply the MGT technique to eight feeder dike segments of the Columbia River basalts (CRB), demonstrating that some dike segments were actively heating host rocks for less than one month, while other …

Synchronous Emplacement Of The Anorthosite Xenolith-Bearing Beaver River Diabase And One Of The Largest Lava Flows On Earth, Yiming Zhang, Nicholas L. Swanson-Hysell, Mark D. Schmitz, James D. Miller, Margaret S. Avery

Geosciences Faculty Publications and Presentations

New geochronologic and paleomagnetic data from the North American Midcontinent Rift (MCR) reveal the synchronous emplacement of the Beaver River diabase, the anorthosite xenoliths within it, and the Greenstone Flow—one of the largest lava flows on Earth. A U-Pb zircon date of 1091.83 ± 0.21 Ma (2σ) from one of the anorthosite xenoliths is consistent with the anorthosite cumulate forming as part of the MCR and provides a maximum age constraint for the Beaver River diabase. Paired with the minimum age constraint of a cross-cutting Silver Bay intrusion (1091.61 ± 0.14 Ma; 2σ), these data tightly …

The Hera Orebody: A Complex Distal (Au–Zn–Pb–Ag–Cu) Skarn In The Cobar Basin Of Central New South Wales, Australia, Corey Wall

Geosciences Faculty Publications and Presentations

The Hera Au–Pb–Zn–Ag deposit in the southeastern Cobar Basin of central New South Wales preserves calc-silicate veins and remnant sandstone/carbonate-hosted skarn within a reduced anchizonal Siluro-Devonian turbidite sequence. The skarn orebody distribution is controlled by a long-lived, basin margin fault system, that has intersected a sedimentary horizon dominated by siliciclastic turbidite, with lesser gritstone and thick sandstone intervals, and rare carbonate-bearing stratigraphy. Foliation (S1) envelopes the orebody and is crosscut by a series of late-stage east–west and north–south trending faults. Skarn at Hera displays mineralogical zonation along strike, from southern spessartine–grossular–biotite–actinolite-rich associations, to central diopside-rich–zoisite–actinolite/tremolite–grossular-bearing associations, through to the northern …

Tracking Induced Seismicity In The Fort Worth Basin, Texas And Northern Oklahoma Using Local And Large-N Style Arrays, Louis Quinones

Earth Sciences Theses and Dissertations

Since 2008, earthquake sequences within the Fort Worth Basin (FWB), north Texas, have been linked to wastewater disposal activities related to unconventional shale gas production. Here, I present my work analyzing and cataloging a complete record of the seismicity occurring within the basin over a period of more than a decade (2008-2020). Analysis of the catalog reveals that the earthquakes generally occur within the Precambrian basement along steeply dipping normal faults, and while overall seismicity rates have decreased since 2016, new faults have become active. I observe strong spatial and temporal correlations between the earthquake locations and wastewater disposal well …

Prevention And Preparedness Of The Messina-Reggio Calabria Strait: An Earthquake Forecasting And Didactic Project, Francesco Di Stefano, Gioacchino Giampaolo Giuliani, Dimitar Ouzounov, Daniele Cataldi, Cristiano Fidani, Angelo D'Errico, Giulia Fioravanti

Mathematics, Physics, and Computer Science Faculty Articles and Research

This contribution is addressed to an introductive university course on the correlation existing between radon emission and earthquakes processes held following a flipped-class approach where students receive didactic materials prior to face-to-face lessons. This research was initially started to investigate the real correlation between Radon emission from the Earth and the occurrence of strong earthquakes by using measurements of hourly Radon flow variation. During quiet seismogenic conditions, we observe an unvarying level of Radon emission in the air. Before a strong earthquake, substantial variations of Radon (²²²Rn) concentration have been observed in the air, probably because of the …

Shallow Rupture Propagation Of Pleistocene Earthquakes Along The Hurricane Fault, Ut, Revealed By Hematite (U-Th)/He Thermochronometry And Textures, Madison P. Taylor, Alexis K. Ault, Margaret L. Odlum, Dennis L. Newell

Geoscience Faculty Research

The material properties and distribution of faults above the seismogenic zone promote or inhibit earthquake rupture propagation. We document the depths and mechanics of fault slip along the seismically active Hurricane fault, UT, with scanning and transmission electron microscopy and hematite (U-Th)/He thermochronometry. Hematite occurs as mm-scale, striated patches on a >10 m2 thin, mirror-like silica fault surface. Hematite textures include bulbous aggregates and cataclasite, overlain by crystalline Fe-oxide nanorods and an amorphous silica layer at the slip interface. Textures reflect mechanical, fluid, and heat-assisted amorphization of hematite and silica-rich host rock that weaken the fault and promote rupture propagation. …

Trace Fossils, Algae, Invertebrate Remains And New U-Pb Detrital Zircon Geochronology From The Lower Cambrian Torneträsk Formation, Northern Sweden, Stephen Mcloughlin, Vivi Vajda, Timothy P. Topper, James L. Crowley, Fan Liu, Ove Johansson, Christian B. Skovsted

Geosciences Faculty Publications and Presentations

Nineteen ichnotaxa, together with algal and invertebrate remains, and various pseudo-traces and sedimentary structures are described from the Torneträsk Formation exposed near Lake Torneträsk, Lapland, Sweden, representing a marked increase in the diversity of biotic traces recorded from this unit. The “lower siltstone” interval of the Torneträsk Formation contains mostly simple pascichnia, fodinichnia and domichnia burrows and trails of low-energy shoreface to intertidal settings. The assemblage has very few forms characteristic of high-energy, soft-sediment, foreshore or upper shoreface environments (representative of the Skolithos ichnofacies).

Uranium-lead (U-Pb) LA-ICPMS analysis of zircon from a thin claystone layer within the “lower siltstone” interval …

A Mélange Of Subduction Ages: Constraints On The Timescale Of Shear Zone Development And Underplating At The Subduction Interface, Catalina Schist (Ca, Usa), K. M. Harvey, S. Walker, P. G. Starr, S. C. Penniston-Dorland, M. J. Kohn, E. F. Baxter

Geosciences Faculty Publications and Presentations

The presence of mélange at the subduction interface influences numerous geochemical and geophysical processes. However, the relationship between the timescales of mélange development, deformation, and resultant mass transport is poorly understood. Here, we use Sm-Nd garnet geochronology to elucidate the timing of peak metamorphism for five garnet amphibolite tectonic blocks from the amphibolite-facies mélange zone of the Catalina Schist (Santa Catalina Island, CA). Ages range from 108 to 116 Ma and do not appear to correlate with the peak metamorphic temperature recorded by each block (between 640 and 740°C). The lack of correlation between age and peak temperature favors the …

Coupled Inversion Of Hydraulic And Self-Potential Data From Transient Outflow Experiments To Estimate Soil Petrophysical Properties, Jing Xie, Yian Cui, Qifei Niu

Geosciences Faculty Publications and Presentations

Hydraulicproperties of soils could play an important role in affecting the partitioning of precipitation in the critical zone. In addition to traditional approaches, in the last two decades, many geophysical methods have been used to aid the hydrologic characterization and measurement of geological materials. In particular, the self-potential (SP) method shows great potential in these hydrogeophysical applications. The objective of this study is to evaluate whether the addition of SP data can improve the estimation of hydraulic properties of soils in an outflow experiment. A stochastic, coupled hydrogeophysical inversion was developed, in which the governing equations were solved using the …

(Re)Proposal Of Three Cambrian Subsystems And Their Geochronology, Ed Landing, Gerd Geyer, Mark D. Schmitz, Thomas Wotte, Artem Kouchinsky

Geosciences Faculty Publications and Presentations

The Cambrian is anomalous among geological systems as many reports divide it into three divisions of indeterminate rank. This use of “lower”, “middle”, and “upper” has been a convenient way to subdivide the Cambrian despite agreement it consists of four global series. Traditional divisions of the system into regional series (Lower, Middle, Upper) reflected local biotic developments not interprovincially correlatable with any precision. However, use of “lower”, “middle”, and “upper” is unsatisfactory. These adjectives lack standard definition, evoke the regional series, and are misused. Notably, there is an almost 50 year use of three Cambrian subsystems and a 1997 proposal …