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2017

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Full-Text Articles in Geophysics and Seismology

Mitigating Non-Linearity In Full Waveform Inversion Using Scaled-Sobolev Norms, Mohammad Akbar Hosain Zuberi Dec 2017

The Sedimentary Imprint Of Pleistocene Glacio-Eustasy: Implications For Global Correlations Of Seismic Sequences, Cecilia M. Mchugh, Craig S. Fulthorpe, Koichi Hoyanagi, Peter Blum, Gregory S. Mountain, Kenneth G. Miller Dec 2017

The Sedimentary Imprint Of Pleistocene Glacio-Eustasy: Implications For Global Correlations Of Seismic Sequences, Cecilia M. Mchugh, Craig S. Fulthorpe, Koichi Hoyanagi, Peter Blum, Gregory S. Mountain, Kenneth G. Miller

Publications and Research

We evaluate lithofacies, chronology, and seismic sequences from the Canterbury Basin, New Zealand passive continental slope (Integrated Ocean Drilling Program [IODP] Expedition 317 Site U1352 and environs) and compare this with slope sequences from the New Jersey passive margin. Our goal is to understand continental slope sedimentation in response to glacio-eustasy and test the concepts of sequence stratigraphy. High-resolution geochemical elemental and lithostratigraphic analyses were calibrated to a chronology constructed from benthic foramininferal oxygen isotopes for the past ~1.8 m.y. We identify lithofacies successions by their unique geochemical and lithologic signature and correlate them with marine isotope stages (MIS) at …


Application Of Tilt Angle Method To The Bouguer Gravity Data Of Western Anatolia, Fikret Doğru, Oya Pamukçu, İlkin Özsöz Dec 2017

Application Of Tilt Angle Method To The Bouguer Gravity Data Of Western Anatolia, Fikret Doğru, Oya Pamukçu, İlkin Özsöz

Bulletin of the Mineral Research and Exploration

In this study, tilt angle method was applied to Western Anatolia gravity data in order to estimate edges of the geological structures. Tilt angle was obtained in two different ways by using gravity and its vertical derivative. In potential field methods, tilt angle technique is expressed as the ratio of vertical derivative to horizontal derivatives of anomaly. In the tilt angle map, 0° contours defines structure edges, half of the distance between ±45° defines depth of upper structure. In the field work of the study, gravity data, which was measured in Western Anatolia, was used to obtain regional anomaly maps …


Investigating The Mechanism Of Deep-Focus Earthquakes Via In-Situ Acoustic Emission Experiments On Fe2sio4 At High Temperature And Pressure, Timothy Officer Dec 2017

Investigating The Mechanism Of Deep-Focus Earthquakes Via In-Situ Acoustic Emission Experiments On Fe2sio4 At High Temperature And Pressure, Timothy Officer

Electronic Thesis and Dissertation Repository

In subduction zones, earthquakes are thought to be associated with faulting that arises from phase transformations. In order to test the viability of this mechanism experimentally, it was necessary to make microseismic measurements while the mineral under investigation was subjected to the pressure and temperature (P,T) conditions corresponding to their environment at depth. A system has been developed capable of making in situ acoustic emission (AE) measurements on samples under P,T conditions representative of the upper mantle and transition zone. Experiments were performed in a 3000-ton multi-anvil press using an 18/11 octahedral cell with 6 piezoelectric transducers mounted on the …


Characterizing Coseismic Ionospheric Disturbance For Surface-Rupturing Earthquakes, Rebekah Faith Lee Dec 2017

Characterizing Coseismic Ionospheric Disturbance For Surface-Rupturing Earthquakes, Rebekah Faith Lee

Boise State University Theses and Dissertations

Coseismic ionospheric disturbances (CID) are commonly identified using global navigation space system (GNSS) satellites. Little research, however, has focused on using total electron content (TEC) observations to characterize acoustic sources on Earth's surface. For this thesis, I investigate the applicability of an analytical method to invert the TEC for the acoustic wave. The inversion is based on the modeling of a transfer function. Deconvolving the TEC by the transfer function gives the acoustic wave. Inverting for the acoustic wave in this way would remove phase differences in the TEC created by atmospheric-ionospheric coupling. I test the assumption in the model …


Seismic Refraction And Electrical Resistivity Tests For Fracture Induced Anisotropy In A Mountain Watershed, Aida Mendieta Dec 2017

Seismic Refraction And Electrical Resistivity Tests For Fracture Induced Anisotropy In A Mountain Watershed, Aida Mendieta

Boise State University Theses and Dissertations

The critical zone (CZ) is the earth’s layer where water, air, rock, and life meet. It is the zone with which humans interact most. The National Research council (2001) defines the CZ as a “heterogeneous, near surface environment in which complex interactions involving rock, soil, water, air, and living organisms regulate the natural habitat and determine the availability of life sustaining resources”. The CZ may extend roughly from the top of the vegetation canopy to the deepest part of the rock column where meteoric water circulates – this is often in the 10 – 30 m range. The upper 1-2 …


Application Of Hydrogeophysical Imaging In The Reynolds Creek Critical Zone Observatory, Travis Nielson Dec 2017

Application Of Hydrogeophysical Imaging In The Reynolds Creek Critical Zone Observatory, Travis Nielson

Boise State University Theses and Dissertations

The critical zone is defined as the upper most portion of the crust extending from the top of unweathered bedrock to the top of the vegetation canopy. It is the zone in which inorganic rock is transformed into biologically useful soils and saprolites in a process termed weathering. Because the critical zone is the connection between the subsurface and surface it plays a role in a wide variety of biological, hydrologic, and climatic processes. Understanding the critical zone though is inherently difficult because its scale and heterogeneity often means direct sampling methods, e.g. soil pits and cores, under represent the …


Seeing Prehistory Through New Lenses: Using Geophysical And Statistical Analysis To Identify Fresh Perspectives Of A 15th Century Mandan Occupation, Amber Marie Mitchum Dec 2017

Seeing Prehistory Through New Lenses: Using Geophysical And Statistical Analysis To Identify Fresh Perspectives Of A 15th Century Mandan Occupation, Amber Marie Mitchum

Graduate Theses and Dissertations

Great Plains prehistoric research has evolved over the course of a century, with many sites like Huff Village (32MO11) in North Dakota recently coming back to the forefront of discussion through new technological applications. Through a majority of its studies and excavations, Huff Village appeared to endure as the final stage in the Middle Missouri tradition. Long thought to reflect only systematically placed long-rectangular structure types of its Middle Missouri predecessors, recent magnetic gradiometry and topographic mapping data revealed circular structure types that deviated from long-held traditions, highlighting new associations with Coalescent groups. A compact system for food capacity was …


Combined Assimilation Of Satellite Precipitation And Soil Moisture: A Case Study Using Trmm And Smos Data, Liao-Fan Lin, Ardeshir M. Ebtehaj, Alejandro N. Flores, Satish Bastola, Rafael L. Bras Dec 2017

Combined Assimilation Of Satellite Precipitation And Soil Moisture: A Case Study Using Trmm And Smos Data, Liao-Fan Lin, Ardeshir M. Ebtehaj, Alejandro N. Flores, Satish Bastola, Rafael L. Bras

Geosciences Faculty Publications and Presentations

This paper presents a framework that enables simultaneous assimilation of satellite precipitation and soil moisture observations into the coupled Weather Research and Forecasting (WRF) and Noah land surface model through variational approaches. The authors tested the framework by assimilating precipitation data from the Tropical Rainfall Measuring Mission (TRMM) and soil moisture data from the Soil Moisture Ocean Salinity (SMOS) satellite. The results show that assimilation of both TRMM and SMOS data can effectively improve the forecast skills of precipitation, top 10-cm soil moisture, and 2-m temperature and specific humidity. Within a 2-day time window, impacts of precipitation data assimilation on …


3d Seismic Interpretation Of A Plio-Pleistocene Mass Transport Deposit In The Deepwater Taranaki Basin Of New Zealand, Francisco Jose Rusconi Dec 2017

3d Seismic Interpretation Of A Plio-Pleistocene Mass Transport Deposit In The Deepwater Taranaki Basin Of New Zealand, Francisco Jose Rusconi

Graduate Theses and Dissertations

A series of Plio-Pleistocene mass transport deposits (MTD) have been identified in the deepwater Taranaki Basin, in New Zealand, using the Romney 3D seismic survey, which covers an area of approximately 2000 km2. One of these MTDs has been chosen for description and interpretation based on high confidence mapping of its boundary surfaces. The deposit exhibits an array of interesting features similar to those documented by researchers elsewhere plus a unique basal feature unlike those previously observed. The basal shear surface exhibits erosional features such as grooves, “monkey fingers”, and glide tracks. Internally, the MTD is typically characterized by low …


Geophysical Delineation Of Megaporosity And Fluid Migration Pathways For Geohazard Characterization Within The Delaware Basin, Culberson County, Texas, Jonathan David Woodard Dec 2017

Geophysical Delineation Of Megaporosity And Fluid Migration Pathways For Geohazard Characterization Within The Delaware Basin, Culberson County, Texas, Jonathan David Woodard

Electronic Theses and Dissertations

ABSTRACT

Differential dissolution of gypsum karst within the Delaware Basin poses a significant threat to infrastructure that society depends on. The study area is located in Culberson County, Texas and traverses a distance of approximately 54 kilometers along RM 652 within the Gypsum Plain which is situated on the northern margin of the Chihuahua Desert and includes outcrops of Castile and Rustler strata that host karst geohazards. Regions of karst geohazard potential have been physically surveyed proximal to the study area in evaporites throughout the Castile Formation outcrop; minimal hazards, in comparison to the Castile Formation, have been documented in …


A Geophysical Investigation Of Stratigraphy And Structure On St. Catherines Island, Georgia, Anne M. Delua Nov 2017

A Geophysical Investigation Of Stratigraphy And Structure On St. Catherines Island, Georgia, Anne M. Delua

Honors College Theses

Geophysical tools were used to investigate potential structural and stratigraphic pathways of the salt water intrusion that is affecting the surficial aquifer on St. Catherines Island, Georgia. Ground penetrating radar (GPR) is a geophysical tool that uses electromagnetic waves to view the subsurface. GPR is used for a variety of applications stratigraphically, biologically, and anthropogenically. GPR electromagnetic waves react to changes in density and composition and type and percentage of pore fluids in sediment and rock. GPR waves also react to interfaces including fractures and faults. GPR waves exhibit attenuation and decreased return signal in materials such as clay. Fresh …


Time Series Analysis Of Surface Deformation Associated With Fluid Injection And Induced Seismicity In Timpson, Texas Using Dinsar Methods, Simon Thorpe Nov 2017

Time Series Analysis Of Surface Deformation Associated With Fluid Injection And Induced Seismicity In Timpson, Texas Using Dinsar Methods, Simon Thorpe

Electronic Thesis and Dissertation Repository

In recent years, a rise in unconventional oil and gas production in North America has been linked to an increase in seismicity rate in these regions (Ellsworth, 2013). As fluid is pumped into deep formations, the state of stress within the subsurface changes, potentially reactivating pre-existing faults and/or causing subsidence or uplift of the surface. Therefore, hydraulic fracturing and/or fluid disposal injection can significantly increase the seismic hazard to communities and structures surrounding the injection sites (Barnhart et al., 2014). On 17th May 2012 an Mw4.8 earthquake occurred near Timpson, TX and has been linked with wastewater injection operations in …


Geophysical Study Of Complex Meteorite Impact Structures, William Zylberman Nov 2017

Geophysical Study Of Complex Meteorite Impact Structures, William Zylberman

Electronic Thesis and Dissertation Repository

Hypervelocity impact craters are the most abundant morphologic features on rocky planetary bodies of the Solar System, except on Earth where they have mostly been erased by plate tectonics, erosion, or are buried under sediments. The internal structure of complex impact craters can only be studied on Earth by using ground-truth geophysical and geological studies. Such approaches - combined with modeling - can reveal how impact cratering, target geological composition, erosion and other post-impact processes can lead to the observed geophysical anomalies, which could also be detected by remote geophysical data on other planetary surfaces. In this work, a multidisciplinary …


Imaging Wetland Hydrogeophysics: Applications Of Critical Zone Hydrogeophysics To Better Understand Hydrogeologic Conditions In Coastal And Inland Wetlands And Waters, Christine Marie Downs Nov 2017

Imaging Wetland Hydrogeophysics: Applications Of Critical Zone Hydrogeophysics To Better Understand Hydrogeologic Conditions In Coastal And Inland Wetlands And Waters, Christine Marie Downs

USF Tampa Graduate Theses and Dissertations

This dissertation consists of three projects utilizing electric and electromagnetic (EM) methods to better understand critical-zone hydrogeologic conditions in select Florida wetlands and waters.

First, a time-lapse electrical resistivity (ER) survey was conducted in section of mangrove forest on a barrier island in southeast Florida to image changes in pore-water salinity in the root zone. ER data show the most variability in the root zone over a 24-hour period, and, generally, the ground is more resistive during the day than overnight.

Second, a suite of three-dimensional forward models, based on varying lateral boundaries and conductivities typical of a coastal wetland, …


How Dredge Pits Evolve Over Time: A Look At Their Geomorphologic Evolution And Infilling Processes, Patrick Robichaux Nov 2017

How Dredge Pits Evolve Over Time: A Look At Their Geomorphologic Evolution And Infilling Processes, Patrick Robichaux

LSU Master's Theses

As coastal environments become more susceptible to land loss through accelerating sea level rise and subsidence, new restoration methods harnessing borrowed sediment are more valuable than ever. Mud-capped dredge pits (MCDPs) are a relatively new source of restoration-quality sediment that has only recently been utilized for beach and barrier island restorations in Louisiana. Because MCDPs have been in use for less than two decades in only a handful sites, little is understood about their evolution over decadal timescales. To improve our understanding of MCDPs after they are dredged, we have conducted a suite of geophysical surveys including bathymetry, sidescan sonar, …


Exploring The Historical Earthquakes Preceding The Giant 1960 Chile Earthquake In A Time-Dependent Seismogenic Zone, Marco Cisternas, Matias Carvajal, Robert Wesson, Lisa L. Ely, Nicolás Gorigoitia Nov 2017

Exploring The Historical Earthquakes Preceding The Giant 1960 Chile Earthquake In A Time-Dependent Seismogenic Zone, Marco Cisternas, Matias Carvajal, Robert Wesson, Lisa L. Ely, Nicolás Gorigoitia

All Faculty Scholarship for the College of the Sciences

New documentary findings and available paleoseismological evidence provide both new insights into the historical seismic sequence that ended with the giant 1960 south‐central Chile earthquake and relevant information about the region’s seismogenic zone. According to the few available written records, this region was previously struck by earthquakes of varying size in 1575, 1737, and 1837. We expanded the existing compilations of the effects of the two latter using unpublished first‐hand accounts found in archives in Chile, Peru, Spain, and New England. We further investigated their sources by comparing the newly unearthed historical data and available paleoseismological evidence with the effects …


Acoustic And Seismic Fields Of Hydraulic Jumps At Varying Froude Numbers, Timothy J. Ronan, Jonathan M. Lees, T. Dylan Mikesell, Jacob F. Anderson, Jeffrey B. Johnson Oct 2017

Acoustic And Seismic Fields Of Hydraulic Jumps At Varying Froude Numbers, Timothy J. Ronan, Jonathan M. Lees, T. Dylan Mikesell, Jacob F. Anderson, Jeffrey B. Johnson

Geosciences Faculty Publications and Presentations

Mechanisms that produce seismic and acoustic wavefields near rivers are poorly understood because of a lack of observations relating temporally dependent river conditions to the near-river seismoacoustic fields. This controlled study at the Harry W. Morrison Dam (HWMD) on the Boise River, Idaho, explores how temporal variation in fluvial systems affects surrounding acoustic and seismic fields. Adjusting the configuration of the HWMD changed the river bathymetry and therefore the form of the standing wave below the dam. The HWMD was adjusted to generate four distinct wave regimes that were parameterized through their dimensionless Froude numbers (Fr) and …


How Useful Is Gsv As An Environmental Observation Tool? An Analysis Of The Evidence So Far., Katherine Nesse, Leah Airt Oct 2017

How Useful Is Gsv As An Environmental Observation Tool? An Analysis Of The Evidence So Far., Katherine Nesse, Leah Airt

SPU Works

Researchers in many disciplines have turned to Google Street View to replace pedestrian- or carbased in-person observation of streetscapes. It is most prevalent within the research literature on the relationship between neighborhood environments and public health but has been used as diverse as disaster recovery, ecology and wildlife habitat, and urban design. Evaluations of the tool have found that the results of GSV-based observation are similar to the results from in-person observation although the similarity depends on the type of characteristic being observed. Larger, permanent and discrete features showed more consistency between the two methods and smaller, transient and judgmental …


New Gps Time Series Analysis And A Simplified Model To Compute An Accurate Seasonal Amplitude Of Tropospheric Delay, Hadis Samadi Alinia Oct 2017

New Gps Time Series Analysis And A Simplified Model To Compute An Accurate Seasonal Amplitude Of Tropospheric Delay, Hadis Samadi Alinia

Electronic Thesis and Dissertation Repository

Horizontal and vertical deformation of the Earth’s crust is due to a variety of different geophysical processes that take place on various spatiotemporal scales. The quality of the observations from spaced-based geodesy instruments such as Global Positioning System (GPS) and differential interferometric synthetic aperture radar (DInSAR) data for monitoring these deformations are dependent on numerous error sources. Therefore, accurately identifying and eliminating the dominant sources of the error, such as troposphere error in GPS signals, is fundamental to obtain high quality, sub-centimeter accuracy levels in positioning results.

In this work, I present the results of double-differenced processing of five years …


Using Isotopes To Constrain Water Flux And Age Estimates In Snow-Influenced Catchments Using The Starr (Spatially Distributed Tracer-Aided Rainfall–Runoff) Model, Pertti Ala-Aho, Doerthe Tetzlaff, James P. Mcnamara, Hjalmar Laudon, Chris Soulsby Oct 2017

Using Isotopes To Constrain Water Flux And Age Estimates In Snow-Influenced Catchments Using The Starr (Spatially Distributed Tracer-Aided Rainfall–Runoff) Model, Pertti Ala-Aho, Doerthe Tetzlaff, James P. Mcnamara, Hjalmar Laudon, Chris Soulsby

Geosciences Faculty Publications and Presentations

Tracer-aided hydrological models are increasingly used to reveal fundamentals of runoff generation processes and water travel times in catchments. Modelling studies integrating stable water isotopes as tracers are mostly based in temperate and warm climates, leaving catchments with strong snow influences underrepresented in the literature. Such catchments are challenging, as the isotopic tracer signals in water entering the catchments as snowmelt are typically distorted from incoming precipitation due to fractionation processes in seasonal snowpack.

We used the Spatially distributed Tracer-Aided Rainfall– Runoff (STARR) model to simulate fluxes, storage, and mixing of water and tracers, as well as estimating water ages …


A Comparison Of Ground Motion Characteristics From Induced Seismic Events In Alberta With Those In Oklahoma, Krista M. Kaski Oct 2017

A Comparison Of Ground Motion Characteristics From Induced Seismic Events In Alberta With Those In Oklahoma, Krista M. Kaski

Electronic Thesis and Dissertation Repository

Ground motions from potentially-induced seismic events in Alberta of magnitude (M) > 3, recorded within 100 km, are empirically characterized in terms of their response spectral shapes and amplitudes. Ground motions are compared statistically to those from induced events in Oklahoma, as well as to three benchmark ground motion prediction equations (GMPEs), derived from natural events. Discrepancies between Alberta and Oklahoma events appear to be magnitude-dependent, and distance-independent. For events greater than M~4, the ground motions appear equivalent in the two regions. High-frequency motions from M< 3.5 events in Alberta are weaker than those of natural events, even those at shallow focal depths. For larger magnitudes, the residuals between the Alberta motions and benchmark GMPEs (Yenier and Atkinson, 2015; Atkinson, 2015; Abrahamson et al., 2014) suggest that observations are in reasonable accord with the models. These results provide a further understanding of ground motions from induced events in Alberta.


Bell Creek Project – Enhanced Oil Recovery Resulting In Associated Co2 Storage, University Of North Dakota. Energy And Environmental Research Center Oct 2017

Bell Creek Project – Enhanced Oil Recovery Resulting In Associated Co2 Storage, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about the Plains CO2 Reduction (PCOR) Partnership research into associated CO2 storage incidental to a commercial enhanced oil recovery (EOR) operation. The project also seeks to develop cost-effective monitoring, verification, and accounting (MVA) techniques to monitor EOR and associated CO2 storage.


Assessing A Multi-Platform Data Fusion Technique In Capturing Spatiotemporal Dynamics Of Heterogeneous Dryland Ecosystems In Topographically Complex Terrain, Peter J. Olsoy, Jessica Mitchell, Nancy F. Glenn, Alejandro N. Flores Oct 2017

Assessing A Multi-Platform Data Fusion Technique In Capturing Spatiotemporal Dynamics Of Heterogeneous Dryland Ecosystems In Topographically Complex Terrain, Peter J. Olsoy, Jessica Mitchell, Nancy F. Glenn, Alejandro N. Flores

Geosciences Faculty Publications and Presentations

Water-limited ecosystems encompass approximately 40% of terrestrial land mass and play a critical role in modulating Earth’s climate and provisioning ecosystem services to humanity. Spaceborne remote sensing is a critical tool for characterizing ecohydrologic patterns and advancing the understanding of the interactions between atmospheric forcings and ecohydrologic responses. Fine to medium scale spatial and temporal resolutions are needed to capture the spatial heterogeneity and the temporally intermittent response of these ecosystems to environmental forcings. Techniques combining complementary remote sensing datasets have been developed, but the heterogeneous nature of these regions present significant challenges. Here we investigate the capacity of one …


Assessment Of Earthquake Site Amplification And Application Of Passive Seismic Methods For Improved Site Classification In The Greater Vancouver Region, British Columbia, Frederick Andrew Jackson Sep 2017

Assessment Of Earthquake Site Amplification And Application Of Passive Seismic Methods For Improved Site Classification In The Greater Vancouver Region, British Columbia, Frederick Andrew Jackson

Electronic Thesis and Dissertation Repository

There is renewed interest to improve seismic microzonation mapping in Greater Vancouver, British Columbia (BC). We investigate local geology as the cause of observed variable ground shaking from the 2015 M 4.7 Vancouver Island earthquake. We observe high amplification at 4-6 Hz on thick sediment and the northern edge of the Fraser River delta, and disparities with current regional seismic microzonation mapping. Site amplification and shear-wave velocity (VS) are assessed from the first borehole earthquake recordings in BC. We also perform ambient vibration analyses at 13 new locations in southwest BC to highlight suitability of passive seismic methods …


Petrophysical Investigations Of The Marathon Cu-Pge Deposit, Marathon, On, Hiruni Gunawardana Sep 2017

Petrophysical Investigations Of The Marathon Cu-Pge Deposit, Marathon, On, Hiruni Gunawardana

Electronic Thesis and Dissertation Repository

Drill core samples obtained from four mineralized zones of the Marathon Cu-PGE deposit in the Coldwell igneous complex have been investigated for their petrophysical characteristics. Remanent magnetization was used as a possible tool to reorient core samples but a drilling induced overprint magnetization dominated the record. Anisotropy of magnetic susceptibility was measured to provide a proxy for the petrofabric of samples obtained from oriented drill cores; a well-defined planar fabric was found to strike 177 and dip 25°W, with down-dip lineation, in excellent agreement with inferred magmatic flow direction based on 3D modeling of mineralized footwall troughs. Magnetite rich lithologies …


The First Earthquake Site Assessments In Alberta, Canada, Joseph J. Farrugia Sep 2017

The First Earthquake Site Assessments In Alberta, Canada, Joseph J. Farrugia

Electronic Thesis and Dissertation Repository

A thorough characterization of the site conditions at Alberta seismic stations is a vital component in assessing seismic hazard in the province. This thesis provides the first earthquake site characterizations in Alberta, including shear-wave velocity (VS) depth profiles, estimates of the average shear-wave velocity in the upper 30 m (VS30) and peak frequency (fpeak), and their validation for prediction of earthquake site amplification. National Building Code of Canada site classes are limited to C and D based on VS30 estimates, with D being the predominant site class. Three …


Lcs-1: A High-Resolution Global Model Of The Lithospheric Magnetic Field Derived From Champ And Swarm Satellite Observations, Nils Olsen, Dhananjay Ravat, Christopher C. Finlay, Livia K. Kother Sep 2017

Lcs-1: A High-Resolution Global Model Of The Lithospheric Magnetic Field Derived From Champ And Swarm Satellite Observations, Nils Olsen, Dhananjay Ravat, Christopher C. Finlay, Livia K. Kother

Earth and Environmental Sciences Faculty Publications

We derive a new model, named LCS-1, of Earth’s lithospheric field based on four years (2006 September–2010 September) of magnetic observations taken by the CHAMP satellite at altitudes lower than 350 km, as well as almost three years (2014 April–2016 December) of measurements taken by the two lower Swarm satellites Alpha and Charlie. The model is determined entirely from magnetic ‘gradient’ data (approximated by finite differences): the north–south gradient is approximated by first differences of 15 s along-track data (for CHAMP and each of the two Swarm satellites), while the east–west gradient is approximated by the difference between observations taken …


Thermal Radiation Anomalies Associated With Major Earthquakes, Dimitar Ouzounov, Sergey Pulinets, Menas Kafatos, Patrick Taylor Sep 2017

Thermal Radiation Anomalies Associated With Major Earthquakes, Dimitar Ouzounov, Sergey Pulinets, Menas Kafatos, Patrick Taylor

Mathematics, Physics, and Computer Science Faculty Articles and Research

Recent developments of remote sensing methods for Earth satellite data analysis contribute to our understanding of earthquake related thermal anomalies. It was realized that the thermal heat fluxes over areas of earthquake preparation is a result of air ionization by radon (and other gases) and consequent water vapor condensation on newly formed ions. Latent heat (LH) is released as a result of this process and leads to the formation of local thermal radiation anomalies (TRA) known as OLR (outgoing Longwave radiation, Ouzounov et al, 2007). We compare the LH energy, obtained by integrating surface latent heat flux (SLHF) over the …


Lidar Aboveground Vegetation Biomass Estimates In Shrublands: Prediction, Uncertainties And Application To Coarser Scales, Aihua Li, Shital Dhakal, Nancy F. Glenn, Lucas P. Spaete Sep 2017

Lidar Aboveground Vegetation Biomass Estimates In Shrublands: Prediction, Uncertainties And Application To Coarser Scales, Aihua Li, Shital Dhakal, Nancy F. Glenn, Lucas P. Spaete

Geosciences Faculty Publications and Presentations

Our study objectives were to model the aboveground biomass in a xeric shrub-steppe landscape with airborne light detection and ranging (Lidar) and explore the uncertainty associated with the models we created. We incorporated vegetation vertical structure information obtained from Lidar with ground-measured biomass data, allowing us to scale shrub biomass from small field sites (1 m subplots and 1 ha plots) to a larger landscape. A series of airborne Lidar-derived vegetation metrics were trained and linked with the field-measured biomass in Random Forests (RF) regression models. A Stepwise Multiple Regression (SMR) model was also explored as a comparison. Our results …