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Articles 181 - 210 of 355
Full-Text Articles in Earth Sciences
Space Geodetic Observation Of The Deformation Cycle Across The Ballenas Transform, Gulf Of California, Christina Plattner, Rocco Malservisi, Falk Amelung, Timothy H. Dixon, Matthias Hackl, Alessandro Verdecchia, Peter Lonsdale, Francisco Suarez-Vidal, Javier Gonzalez-Garcia
Space Geodetic Observation Of The Deformation Cycle Across The Ballenas Transform, Gulf Of California, Christina Plattner, Rocco Malservisi, Falk Amelung, Timothy H. Dixon, Matthias Hackl, Alessandro Verdecchia, Peter Lonsdale, Francisco Suarez-Vidal, Javier Gonzalez-Garcia
School of Geosciences Faculty and Staff Publications
The Gulf of California, Mexico, accommodates ~90% of North America‐Pacific plate relative motion. While most of this motion occurs on marine transform faults and spreading centers, several fault segments in the central Gulf come close to peninsular Baja California. Here we present Global Positioning System and interferometric synthetic aperture radar data near the Ballenas transform fault, separating the peninsula from Angel de la Guarda Island. We observe interseismic motion between June 2004 and May 2009 and displacements associated with the 3 August 2009 Mw 6.9 earthquake. From the interseismic data we estimate a locking depth of 9–12.5 km and a …
How Many Explosive Eruptions Are Missing From The Geologic Record? Analysis Of The Quaternary Record Of Large Magnitude Explosive Eruptions In Japan, Koji Kiyosugi, Charles B. Connor, Robert S. J. Sparks, Helen S. Crosweller, Sarah K. Brown, Lee Siebert, Ting Wang, Shinji Takarada
How Many Explosive Eruptions Are Missing From The Geologic Record? Analysis Of The Quaternary Record Of Large Magnitude Explosive Eruptions In Japan, Koji Kiyosugi, Charles B. Connor, Robert S. J. Sparks, Helen S. Crosweller, Sarah K. Brown, Lee Siebert, Ting Wang, Shinji Takarada
School of Geosciences Faculty and Staff Publications
Large magnitude explosive eruptions in Japan were compiled for the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database. Here we use this dataset to investigate the under-recording of Japanese explosive eruptions. We identify under-recording of Volcanic Explosivity Index (VEI) 4–5 eruptions on two timescales. Model fitting and Akaike’s information criterion (AIC and AICc) model selection suggest that these trends can be represented with the double exponential decay model, reflecting geologic processes. The time series of the recording rate of larger eruptions (VEI 6 and 7) show a slowly decreasing trend in comparison to smaller eruptions. These time series can be represented …
Constraints On Soluble Aerosol Iron Flux To The Southern Ocean At The Last Glacial Maximum, Tim M. Conway, E. W. Wolff, R. Röthlisberger, R. Mulvaney, H. E. Elderfield
Constraints On Soluble Aerosol Iron Flux To The Southern Ocean At The Last Glacial Maximum, Tim M. Conway, E. W. Wolff, R. Röthlisberger, R. Mulvaney, H. E. Elderfield
School of Geosciences Faculty and Staff Publications
Relief of iron (Fe) limitation in the Southern Ocean during ice ages, with potentially increased carbon storage in the ocean, has been invoked as one driver of glacial–interglacial atmospheric CO2 cycles. Ice and marine sediment records demonstrate that atmospheric dust supply to the oceans increased by up to an order of magnitude during glacial intervals. However, poor constraints on soluble atmospheric Fe fluxes to the oceans limit assessment of the role of Fe in glacial–interglacial change. Here, using novel techniques, we present estimates of water- and seawater-soluble Fe solubility in Last Glacial Maximum (LGM) atmospheric dust from the European …
Construction And Destruction Of Mont Pelée Volcano: Volumes And Rates Constrained From A Geomorphological Model Of Evolution, Aurélie Germa, Pierre Lahitte, Xavier Quidelleur
Construction And Destruction Of Mont Pelée Volcano: Volumes And Rates Constrained From A Geomorphological Model Of Evolution, Aurélie Germa, Pierre Lahitte, Xavier Quidelleur
School of Geosciences Faculty and Staff Publications
This study presents long‐term volumes and construction rates for the Mont Conil‐Mont Pelée volcano and rate estimates at which volcanic activity creates relief. An algorithm, ShapeVolc, is used to numerically model topographic surfaces. Volcano morphology is analyzed using current digital elevation model in combination with mapped geology to produce 10 paleotopographies at the end of four constructional stages and three destructional events. Volumes of each constructional stage were estimated at about 35.2 km3, 26.2 km3, 8.3 km3, and 2.5 km3 for a total cumulative erupted volume of 72.2 km3. We estimate …
Multiscale Postseismic Behavior On A Megathrust: The 2012 Nicoya Earthquake, Costa Rica, Rocco Malservisi, Susan Y. Schwartz, Nicholas Voss, Marino Protti, Victor Gonzalez, Timothy H. Dixon, Yan Jiang, Andrew V. Newman, Jacob Richardson, Jacob I. Walter, Denis Voyenko
Multiscale Postseismic Behavior On A Megathrust: The 2012 Nicoya Earthquake, Costa Rica, Rocco Malservisi, Susan Y. Schwartz, Nicholas Voss, Marino Protti, Victor Gonzalez, Timothy H. Dixon, Yan Jiang, Andrew V. Newman, Jacob Richardson, Jacob I. Walter, Denis Voyenko
School of Geosciences Faculty and Staff Publications
The Nicoya Peninsula in northwest Costa Rica overlies a section of the subduction megathrust along the Middle America Trench. On 5 September 2012, a moment magnitude 7.6 megathrust earthquake occurred beneath a dense network of continuous GPS and seismic stations. Many of the GPS stations recorded the event at high rate, 1 Hz or better. We analyze the temporal and spatial evolution of surface deformation after the earthquake. Our results show that the main rupture was followed by significant afterslip within the first 3 h following the main event. The behavior of the surface displacement can be represented by relaxation …
Geographically Isolated Wetlands: Rethinking A Misnomer, David M. Mushet, Aram J. K. Calhoun, Laurie C. Alexander, Matthew J. Cohen, Edward S. Dekeyser, Laurie Fowler, Charles R. Lane, Mark C. Rains, Susan C. Walls
Geographically Isolated Wetlands: Rethinking A Misnomer, David M. Mushet, Aram J. K. Calhoun, Laurie C. Alexander, Matthew J. Cohen, Edward S. Dekeyser, Laurie Fowler, Charles R. Lane, Mark C. Rains, Susan C. Walls
School of Geosciences Faculty and Staff Publications
We explore the category “geographically isolated wetlands” (GIWs; i.e., wetlands completely surrounded by uplands at the local scale) as used in the wetland sciences. As currently used, the GIW category (1) hampers scientific efforts by obscuring important hydrological and ecological differences among multiple wetland functional types, (2) aggregates wetlands in a manner not reflective of regulatory and management information needs, (3) implies wetlands so described are in some way “isolated,” an often incorrect implication, (4) is inconsistent with more broadly used and accepted concepts of “geographic isolation,” and (5) has injected unnecessary confusion into scientific investigations and discussions. Instead, we …
Peninsular Florida Stream Systems: Guidance For Their Classification And Restoration, John H. Kiefer, Joann Mossa, Kristen B. Nowak, William R. Wise, Kenneth M. Portier, Thomas Crisman
Peninsular Florida Stream Systems: Guidance For Their Classification And Restoration, John H. Kiefer, Joann Mossa, Kristen B. Nowak, William R. Wise, Kenneth M. Portier, Thomas Crisman
School of Geosciences Faculty and Staff Publications
This project was performed to improve understanding of key physical and ecological attributes of natural streams in peninsular Florida in order to derive a practical process-based classification system; and also to provide design aids to assist with stream restoration in rural settings. Fifty-six of the best remaining stream systems in the peninsula were selected for monitoring of more than 120 quantitative variables known to associate with key stream system processes. The sites covered a wide range of physical gradients including soil drainage condition, drainage area, and valley slope, and were observed at watershed, valley, channel and patch scales. Hierarchical cluster …
2014 Oxford Volcano Seismology Discussion Workshop Report, Mel Rodgers, David Pyle, Tamsin Mather, Diana Roman, Mark Thomas
2014 Oxford Volcano Seismology Discussion Workshop Report, Mel Rodgers, David Pyle, Tamsin Mather, Diana Roman, Mark Thomas
School of Geosciences Faculty and Staff Publications
No abstract provided.
Multi-Year Observations Of Breiðamerkurjökull, A Marine-Terminating Glacier In Southeastern Iceland, Using Terrestrial Radar Interferometry, Denis Voytenko, Timothy H. Dixon, Ian M. Howat, Noel Gourmelen, Chad Lembke, Charles L. Werner, Santiago De La Peña, Björn Oddsson
Multi-Year Observations Of Breiðamerkurjökull, A Marine-Terminating Glacier In Southeastern Iceland, Using Terrestrial Radar Interferometry, Denis Voytenko, Timothy H. Dixon, Ian M. Howat, Noel Gourmelen, Chad Lembke, Charles L. Werner, Santiago De La Peña, Björn Oddsson
School of Geosciences Faculty and Staff Publications
Terrestrial radar interferometry (TRI) is a new technique for studying ice motion and volume change of glaciers. TRI is especially useful for temporally and spatially dense measurements of highly dynamic glacial termini. We conducted a TRI survey of Breiðamerkurjökull, a marine-terminating glacier in Iceland, imaging its terminus near the end of the melt season in 2011, 2012 and 2013. The ice velocities were as high as 5 m d−1, with the fastest velocities near the calving front. Retreat of the glacier over the 3 year observation period was accompanied by strong embayment formation. Iceberg tracking with the radar shows high …
Did Shell-Crushing Crabs Trigger An Escalatory Arms Race In The Aftermath Of A Late Neogene Regional Mass Extinction Event? An Experimental Test, Lisa B. Whitenack, Gregory S. Herbert
Did Shell-Crushing Crabs Trigger An Escalatory Arms Race In The Aftermath Of A Late Neogene Regional Mass Extinction Event? An Experimental Test, Lisa B. Whitenack, Gregory S. Herbert
School of Geosciences Faculty and Staff Publications
A regional mass extinction event in the late Neogene western Atlantic is widely thought to have generated evolutionary opportunities for survivors, including enemy-related adaptation (escalation). The Strombus alatus species complex is one potential example of this phenomenon. Strombid gastropods are abundant in the Plio-Pleistocene fossil record and Recent in subtropical Florida, and the percentage of these shells bearing a row of short spines on the last whorl increased from nearly zero to almost 100% over this time. As shell ornamentation is one of the most frequently cited defenses against both peeling and crushing predators, we exposed live spined and spineless …
Mapping Robinia Pseudoacacia Forest Health Conditions By Using Combined Spectral, Spatial, And Textural Information Extracted From Ikonos Imagery And Random Forest Classifier, Hong Wang, Yu Zhao, Ruiliang Pu
Mapping Robinia Pseudoacacia Forest Health Conditions By Using Combined Spectral, Spatial, And Textural Information Extracted From Ikonos Imagery And Random Forest Classifier, Hong Wang, Yu Zhao, Ruiliang Pu
School of Geosciences Faculty and Staff Publications
The textural and spatial information extracted from very high resolution (VHR) remote sensing imagery provides complementary information for applications in which the spectral information is not sufficient for identification of spectrally similar landscape features. In this study grey-level co-occurrence matrix (GLCM) textures and a local statistical analysis Getis statistic (Gi), computed from IKONOS multispectral (MS) imagery acquired from the Yellow River Delta in China, along with a random forest (RF) classifier, were used to discriminate Robina pseudoacacia tree health levels. Specifically, eight GLCM texture features (mean, variance, homogeneity, dissimilarity, contrast, entropy, angular second moment, and correlation) were first calculated from …
Earthquake And Tsunami Forecasts: Relation Of Slow Slip Events To Subsequent Earthquake Rupture, Timothy H. Dixon, Yan Jiang, Rocco Malservisi, Robert Mccaffrey, Nicholas Voss, Marino Protti, Victor Gonzalez
Earthquake And Tsunami Forecasts: Relation Of Slow Slip Events To Subsequent Earthquake Rupture, Timothy H. Dixon, Yan Jiang, Rocco Malservisi, Robert Mccaffrey, Nicholas Voss, Marino Protti, Victor Gonzalez
School of Geosciences Faculty and Staff Publications
The 5 September 2012 Mw 7.6 earthquake on the Costa Rica subduction plate boundary followed a 62-y interseismic period. High-precision GPS recorded numerous slow slip events (SSEs) in the decade leading up to the earthquake, both up-dip and down-dip of seismic rupture. Deeper SSEs were larger than shallower ones and, if characteristic of the interseismic period, release most locking down-dip of the earthquake, limiting down-dip rupture and earthquake magnitude. Shallower SSEs were smaller, accounting for some but not all interseismic locking. One SSE occurred several months before the earthquake, but changes in Mohr–Coulomb failure stress were probably too small to …
Redox Chemistry In The Phosphorus Biogeochemical Cycle, Matthew A. Pasek, Jacqueline M. Sampson, Zachary Atlas
Redox Chemistry In The Phosphorus Biogeochemical Cycle, Matthew A. Pasek, Jacqueline M. Sampson, Zachary Atlas
School of Geosciences Faculty and Staff Publications
The element phosphorus (P) controls growth in many ecosystems as the limiting nutrient, where it is broadly considered to reside as pentavalent P in phosphate minerals and organic esters. Exceptions to pentavalent P include phosphine—PH3—a trace atmospheric gas, and phosphite and hypophosphite, P anions that have been detected recently in lightning strikes, eutrophic lakes, geothermal springs, and termite hindguts. Reduced oxidation state P compounds include the phosphonates, characterized by C−P bonds, which bear up to 25% of total organic dissolved phosphorus. Reduced P compounds have been considered to be rare; however, the microbial ability to use reduced P …
The Biogeochemical Cycling Of Zinc And Zinc Isotopes In The North Atlantic Ocean, Tim M. Conway, Seth G. John
The Biogeochemical Cycling Of Zinc And Zinc Isotopes In The North Atlantic Ocean, Tim M. Conway, Seth G. John
School of Geosciences Faculty and Staff Publications
Zinc (Zn) is a marine micronutrient, with an overall oceanic distribution mirroring the major macronutrients, especially silicate. Seawater Zn isotope ratios (δ66Zn) are a relatively new oceanographic parameter which may offer insights into the biogeochemical cycling of Zn. To date, the handful of published studies of seawater δ66Zn show the global deep ocean to be both remarkably homogeneous (approximately +0.5‰) and isotopically heavier than the marine sources of Zn (+0.1 to +0.3‰). Here we present the first high‐resolution oceanic section of δ66Zn, from the U.S. GEOTRACES GA03 North Atlantic Transect, from Lisbon to …
A Seasonally Modulated Earthquake Swarm Near Maupin, Oregon, Jochen Braunmiller, John L. Nabelek, Anne M. Trehu
A Seasonally Modulated Earthquake Swarm Near Maupin, Oregon, Jochen Braunmiller, John L. Nabelek, Anne M. Trehu
School of Geosciences Faculty and Staff Publications
From December 2006 to November 2011, the Pacific Northwest Seismic Network (PNSN) reported 467 earthquakes in a swarm 60 km east of Mt Hood near the town of Maupin, Oregon. The swarm included 20 MD ≥ 3.0 events, which account for over 80 per cent of the cumulative seismic moment release of the sequence. Relocation of 45 MD≥ 2.5 earthquakes and moment tensor analysis of nine 3.3 ≤ Mw ≤ 3.9 earthquakes reveals right-lateral strike-slip motion on a north-northwest trending, 70° west dipping, 1 km2 active fault patch at about 17 km depth. The swarm started …
Organizing A Study Abroad Trip—A Faculty Perspective, Jennifer Collins
Organizing A Study Abroad Trip—A Faculty Perspective, Jennifer Collins
School of Geosciences Faculty and Staff Publications
No abstract provided.
Digital Dissection – Using Contrast‐Enhanced Computed Tomography Scanning To Elucidate Hard‐ And Soft‐Tissue Anatomy In The Common Buzzard Buteo Buteo, Stephan Lautenschlager, Jen A. Bright, Emily J. Rayfield
Digital Dissection – Using Contrast‐Enhanced Computed Tomography Scanning To Elucidate Hard‐ And Soft‐Tissue Anatomy In The Common Buzzard Buteo Buteo, Stephan Lautenschlager, Jen A. Bright, Emily J. Rayfield
School of Geosciences Faculty and Staff Publications
Gross dissection has a long history as a tool for the study of human or animal soft‐ and hard‐tissue anatomy. However, apart from being a time‐consuming and invasive method, dissection is often unsuitable for very small specimens and often cannot capture spatial relationships of the individual soft‐tissue structures. The handful of comprehensive studies on avian anatomy using traditional dissection techniques focus nearly exclusively on domestic birds, whereas raptorial birds, and in particular their cranial soft tissues, are essentially absent from the literature. Here, we digitally dissect, identify, and document the soft‐tissue anatomy of the Common Buzzard (Buteo buteo) …
Monitoring Powdery Mildew Of Winter Wheat By Using Moderate Resolution Multi-Temporal Satellite Imagery, Jingcheng Zhang, Ruiliang Pu, Lin Yuan, Jihua Wang, Wenjiang Huang, Guijun Yang
Monitoring Powdery Mildew Of Winter Wheat By Using Moderate Resolution Multi-Temporal Satellite Imagery, Jingcheng Zhang, Ruiliang Pu, Lin Yuan, Jihua Wang, Wenjiang Huang, Guijun Yang
School of Geosciences Faculty and Staff Publications
Powdery mildew is one of the most serious diseases that have a significant impact on the production of winter wheat. As an effective alternative to traditional sampling methods, remote sensing can be a useful tool in disease detection. This study attempted to use multi-temporal moderate resolution satellite-based data of surface reflectances in blue (B), green (G), red (R) and near infrared (NIR) bands from HJ-CCD (CCD sensor on Huanjing satellite) to monitor disease at a regional scale. In a suburban area in Beijing, China, an extensive field campaign for disease intensity survey was conducted at key growth stages of winter …
Vhub: A Knowledge Management System To Facilitate Online Collaborative Volcano Modeling And Research, José L. Palma, Leah Courtland, Sylvain J. Charbonnier, Riccardo Tortini, Greg A. Valentine
Vhub: A Knowledge Management System To Facilitate Online Collaborative Volcano Modeling And Research, José L. Palma, Leah Courtland, Sylvain J. Charbonnier, Riccardo Tortini, Greg A. Valentine
School of Geosciences Faculty and Staff Publications
Knowledge of volcanic systems and the hazards they produce is rapidly advancing as internet resources become more readily accessible, new and more sensitive field techniques are developed, and ever greater amounts of data are collected. Such rapid advances drive the need for an online collaborative knowledge management system that enables the sharing of volcanological information, and modeling and analysis tools. Vhub (http://vhub.org) is a community cyberinfrastructure platform designed for collaboration in volcanology research, education, outreach, and discovery that complements existing volcano databases and other cyberinfrastructure projects. Vhub is unique in its functionality as a nucleus for the creation …
Integrating People And Place: A Density-Based Measure For Assessing Accessibility To Opportunities, Mark Horner, Joni A. Downs
Integrating People And Place: A Density-Based Measure For Assessing Accessibility To Opportunities, Mark Horner, Joni A. Downs
School of Geosciences Faculty and Staff Publications
Mobile object analysis is a well-studied area of transportation and geographic information science (GIScience). Mobile objects may include people, animals, or vehicles. Time geography remains a key theoretical framework for understanding mobile objects' movement possibilities. Recent efforts have sought to develop probabilistic methods of time geography by exploring questions of data uncertainty, spatial representation, and other limitations of classical approaches. Along these lines, work has blended time geography and kernel density estimation in order to delineate the probable locations of mobile objects in both continuous and discrete network space. This suite of techniques is known as time geographic density estimation …
Searching For Cold-Adapted Microorganisms In The Underground Glacier Of Scarisoara Ice Cave, Romania, Alexandra Maria Hillebrand-Voiculescu, Corina Itcus, Ioan Ardelean, Denisa Pascu, Aurel Persoiu, Andreea Rusu, Traian Brad, Elena Popa, Bogdan P. Onac, Christina Purcarea
Searching For Cold-Adapted Microorganisms In The Underground Glacier Of Scarisoara Ice Cave, Romania, Alexandra Maria Hillebrand-Voiculescu, Corina Itcus, Ioan Ardelean, Denisa Pascu, Aurel Persoiu, Andreea Rusu, Traian Brad, Elena Popa, Bogdan P. Onac, Christina Purcarea
School of Geosciences Faculty and Staff Publications
Scarisoara Ice Cave (Romania) hosts one of world’s largest and oldest underground glacier. While no studies were carried out on the existence of microorganisms in this cave’s ice block, our interest is to investigate the presence of microorganisms and their chronological distribution in the cave’s subterranean ice in relationship with past climatic changes. Samples were collected from ice layers of different age (from present to ~900 cal. yrs. BP), and the diversity of embedded microbial communities was assessed by classical cultivation and molecular techniques. The microorganisms from icesediments were cultivated at 4 °C and 15 °C, in the presence and …
City Of Tampa Urban Forest Management, Monitoring And Policy, Shawn M. Landry, Robert J. Northrop, Michael G. Andreu, Kathy Beck
City Of Tampa Urban Forest Management, Monitoring And Policy, Shawn M. Landry, Robert J. Northrop, Michael G. Andreu, Kathy Beck
School of Geosciences Faculty and Staff Publications
No abstract provided.
A Method For Estimating Ice Mass Loss From Relative Insar Observations: Application To The Vatnajökull Ice Cap, Iceland, Wenliang Zhao, Falk Amelung, Timothy H. Dixon, Shimon Wdowinski, Rocco Malservisi
A Method For Estimating Ice Mass Loss From Relative Insar Observations: Application To The Vatnajökull Ice Cap, Iceland, Wenliang Zhao, Falk Amelung, Timothy H. Dixon, Shimon Wdowinski, Rocco Malservisi
School of Geosciences Faculty and Staff Publications
We present a new method for estimating ice mass loss from glaciers and ice sheets using Interferometric Synthetic Aperture Radar (InSAR) time‐series data. We use a linear inversion method based on observations of nearby bedrock uplift and a solution for surface loading of an elastic half‐space. The method assumes that mass loss is focused on lower elevation terminal regions of the glacier or ice sheet, and that there is an exponential decrease in thinning rate toward the higher elevation interior. We apply the method to uplift rates between 1995 and 2009 near Vatnajökull, Iceland. The data reveal up to 13 …
City Of Tampa Urban Forest Management Plan, Robert J. Northrop, Kathy Beck, Rob Irving, Shawn M. Landry, Michael G. Andreu
City Of Tampa Urban Forest Management Plan, Robert J. Northrop, Kathy Beck, Rob Irving, Shawn M. Landry, Michael G. Andreu
School of Geosciences Faculty and Staff Publications
No abstract provided.
The 5 September 2012 Nicoya, Costa Rica Mw 7.6 Earthquake Rupture Process From Joint Inversion Of High‐Rate Gps, Strong‐Motion, And Teleseismic P Wave Data And Its Relationship To Adjacent Plate Boundary Interface Properties, Han Yue, Thorne Lay, Susan Y. Schwartz, Luis Rivera, Marino Protti, Timothy H. Dixon, Susan Owen, Andrew V. Newman
The 5 September 2012 Nicoya, Costa Rica Mw 7.6 Earthquake Rupture Process From Joint Inversion Of High‐Rate Gps, Strong‐Motion, And Teleseismic P Wave Data And Its Relationship To Adjacent Plate Boundary Interface Properties, Han Yue, Thorne Lay, Susan Y. Schwartz, Luis Rivera, Marino Protti, Timothy H. Dixon, Susan Owen, Andrew V. Newman
School of Geosciences Faculty and Staff Publications
On 5 September 2012, a large thrust earthquake (Mw 7.6) ruptured a densely instrumented seismic gap on the shallow‐dipping plate boundary beneath the Nicoya Peninsula, Costa Rica. Ground motion recordings directly above the rupture zone provide a unique opportunity to study the detailed source process of a large shallow megathrust earthquake using very nearby land observations. Hypocenter relocation using local seismic network data indicates that the event initiated with small emergent seismic waves from a hypocenter ~10 km offshore, 13 km deep on the megathrust. A joint finite‐fault inversion using high‐rate GPS, strong‐motion ground velocity recordings, GPS static offsets, …
Insights Into Distributed Plate Rates Across The Walker Lane From Gps Geodesy, Zachery M. Lifton, Andrew V. Newman, Kurt L. Frankel, Christopher W. Johnson, Timothy H. Dixon
Insights Into Distributed Plate Rates Across The Walker Lane From Gps Geodesy, Zachery M. Lifton, Andrew V. Newman, Kurt L. Frankel, Christopher W. Johnson, Timothy H. Dixon
School of Geosciences Faculty and Staff Publications
Contemporary geodetic slip rates are observed to be approximately two times greater than late Pleistocene geologic slip rates across the southern Walker Lane. Using a dense GPS network, we compare the present‐day crustal velocities to observed geologic slip rates in the region. We find that the Walker Lane is characterized by a smooth transition from westward extension in the Basin and Range to northwestward motion of the Sierra Nevada block. The GPS velocity field indicates that (1) plate parallel (N37°W) velocities define a velocity differential of 10.6 ± 0.5 mm/yr between the western Basin and Range and the Sierra Nevada …
City Of Tampa 2011 Urban Forest Analysis: The Structure, Composition, Function And Economic Benefits Of Trees And The Urban Forest, Shawn M. Landry, Robert J. Northrop, Madison Andreu, Carolyn Cheatham Rhodes
City Of Tampa 2011 Urban Forest Analysis: The Structure, Composition, Function And Economic Benefits Of Trees And The Urban Forest, Shawn M. Landry, Robert J. Northrop, Madison Andreu, Carolyn Cheatham Rhodes
School of Geosciences Faculty and Staff Publications
No abstract provided.
Initial Morphologic Evolution Of Perdido Key Berm Nourishment, Florida, Ping Wang, Katherine E. Brutsche, Tanya M. Beck, Julie D. Rosati, Linda S. Lillycrop
Initial Morphologic Evolution Of Perdido Key Berm Nourishment, Florida, Ping Wang, Katherine E. Brutsche, Tanya M. Beck, Julie D. Rosati, Linda S. Lillycrop
School of Geosciences Faculty and Staff Publications
This Coastal and Hydraulics Engineering Technical Note (CHETN) documents the initial morphologic evolution of the Perdido Key, FL, swash-zone berm based on beach-nearshore profile, sediment samples, and nearshore wave data collected during the first six months after berm construction. The US Army Corps of Engineers (USACE), Mobile District, dredged the navigation channel at Pensacola Pass, FL, from November 2011 to January 2012 and placed the 520,000 cubic yards (yd3) of dredged sand as a swash-zone berm nearshore of Perdido Key, FL. Beach quality sands are a valuable resource within the coastal zone in maintaining regional sediment balance. Compared to a …
Performance Monitoring Of A Nearshore Berm At Ft. Myers Beach, Florida: Final Report, Ping Wang, Katherine E. Brutsche, James W. Lagrone, Tanya M. Beck, Julie D. Rosati, Linda S. Lillycrop
Performance Monitoring Of A Nearshore Berm At Ft. Myers Beach, Florida: Final Report, Ping Wang, Katherine E. Brutsche, James W. Lagrone, Tanya M. Beck, Julie D. Rosati, Linda S. Lillycrop
School of Geosciences Faculty and Staff Publications
This report documents the placement and monitoring of an active nearshore berm at Ft. Myers Beach, Florida. From May to July 2009, mixed sand and finer sediment dredged from a nearby inlet were placed in the active littoral zone in the form of a bar-shaped nearshore berm. Six sets of beach-nearshore profile surveys and two periods of sediment sampling along profiles were collected. The Ft. Myers Beach nearshore berm migrated onshore roughly 300 ft during the first 2 years. The elevation of the berm crest increased up to 2 ft. Nearly half of the onshore migration occurred during the first …
Distinct Iron Isotopic Signatures And Supply From Marine Sediment Dissolution, William B. Homoky, Seth G. John, Tim M. Conway, Rachel A. Mills
Distinct Iron Isotopic Signatures And Supply From Marine Sediment Dissolution, William B. Homoky, Seth G. John, Tim M. Conway, Rachel A. Mills
School of Geosciences Faculty and Staff Publications
Oceanic iron inputs must be traced and quantified to learn how they affect primary productivity and climate. Chemical reduction of iron in continental margin sediments provides a substantial dissolved flux to the oceans, which is isotopically lighter than the crust, and so may be distinguished in seawater from other sources, such as wind-blown dust. However, heavy iron isotopes measured in seawater have recently led to the proposition of another source of dissolved iron from ‘non-reductive’ dissolution of continental margins. Here we present the first pore water iron isotope data from a passive-tectonic and semi-arid ocean margin (South Africa), which reveals …