Geology Commons^™

Predicting The Geodetic Signature Of Mw 8 Slow Slip Events, Brendan J. Meade, John P. Loveless

Geosciences: Faculty Publications

Elastic dislocation models of geodetic measurements

above subduction zones have led to the identification of

MW 6.0– 7.2 slow slip events (SSEs) that release elastic

strain over periods of days to months, but great (MW 8)

SSEs have remained unidentified. We extrapolate

observations of SSE duration and slip magnitude to show

that slip velocity decreases with event magnitude and

predict that the slip velocity of MW 8 SSEs is 50 mm/yr.

The slip velocity for great SSEs may never exceed the

plate convergence rate and thus never produce a reversal

in trench perpendicular motion. Instead, geodetically

constrained estimates of apparent …

Surface Cracks Record Long-Term Seismic Segmentation Of The Andean Margin, John P. Loveless, Richard W. Allmendinger, Matthew E. Pritchard, Jordan L. Garroway, Gabriel González

Geosciences: Faculty Publications

Understanding the long-term patterns of great earthquake rupture along a subduction zone provides a framework for assessing modern seismic hazard. However, evidence that can be used to infer the size and location of past earthquakes is typically erased by erosion after a few thousand years. Meter-scale cracks that cut the surface of coastal areas in northern Chile and southern Peru preserve a record of earthquakes spanning several hundred thousand years owing to the hyperarid climate of the region. These cracks have been observed to form during and/or shortly after strong subduction earthquakes, are preserved for long time periods throughout the …

Eogenetic Karst Of The Carbonate Islands Of The Northern Marianas [Abstract], Kevin W. Stafford, John W. Jenson, John E. Mylroie

Faculty Presentations

No abstract provided.

Ascending Water Of The Delaware Basin, Southeastern New Mexico, And Far West Texas [Abstract], Kevin W. Stafford, Raymond Nance

Faculty Presentations

No abstract provided.

Creating Lakes From Open Pit Mines: Processes And Considerations, Emphasis On Northern Environments, Christopher H. Gammons, Les N. Harris, James M. Castro, Peter A. Cott, Bruce W. Hanna

Geological Engineering

Creating Lakes from Open Pit Mines: Processes and Considerations, Emphasis on Northern Environments. This document summarizes the literature of mining pit lakes (through 2007), with a particular focus on issues that are likely to be of special relevance to the creation and management of pit lakes in northern climates. Pit lakes are simply waterbodies formed by filling the open pit left upon the completion of mining operations with water. Like natural lakes, mining pit lakes display a huge diversity in each of these subject areas. However, pit lakes are young and therefore are typically in a non-equilibrium state with respect …

An Inventory And Condition Survey Of The Lower Murchison River Area, Western Australia, P Hennig

Technical Bulletins

The inventory and condition survey of the lower Murchison River area, undertaken by the Department of Agriculture and Food, Western Australia (DAFWA) between 2002 and 2003, describes and maps the natural resources of the region’s pastoral leasehold land. This survey report provides a baseline record of the existence and condition of the natural area’s resources, to assist with the planning and implementation of land management practices. The report identified and described the condition of soils, landforms, vegetation, habitat, ecosystems, and declared plants and animals. It also assessed the impact of pastoralism and made land management recommendations. This survey report presents …

The Biscayne Aquifer Of Southeastern Florida, Kevin J. Cunningham, Lee J. Florea

Earth, Environmental, and Atmospheric Sciences Faculty Publications

No abstract provided.

The Cumberland Plateau Of Eastern Kentucky, Larry C. Simpson, Lee J. Florea

Earth, Environmental, and Atmospheric Sciences Faculty Publications

No abstract provided.

The Southeastern Coastal Plain: An Overview, Lee J. Florea, H. L. Vacher

Earth, Environmental, and Atmospheric Sciences Faculty Publications

No abstract provided.

Caves And Karst Of West-Central Florida, Lee J. Florea, David A. Budd, Robert B. Brinkman

Earth, Environmental, and Atmospheric Sciences Faculty Publications

No abstract provided.

The Pecos River Hypogene Speleogenetic Province: A Basin-Scale Karst Paradigm For Eastern New Mexico And West Texas, Usa, Kevin W. Stafford, Alexander Klimchouk, Lewis Land, Marcus O. Gary

Faculty Publications

Since the mid-Tertiary, lateral migration and entrenchment of the Pecos River Valley in eastern New Mexico and west Texas, USA, has significantly influenced regional groundwater flow paths, providing a focus for ascending flow in multi-storey artesian systems and a powerful potentiometric driving force for hypogene speleogenesis. Individual occurrences of hypogene karst phenomena associated with the central Pecos River Valley are widespread throughout the greater Delaware Basin region, including development in a wide range of Permian carbonate and evaporate fades. Hypogene occurrences are well-documented as far north as Santa Rosa, New Mexico and as far south as Lake Amistad, Texas. Throughout …

Structured Decision Making As A Conceptual Framework To Identify Thresholds For Conservation And Management, Julien Martin, Michael C. Runge, James D. Nichols, Bruce C. Lubow, William L. Kendall

United States Geological Survey: Staff Publications

Thresholds and their relevance to conservation have become a major topic of discussion in the ecological literature. Unfortunately, in many cases the lack of a clear conceptual framework for thinking about thresholds may have led to confusion in attempts to apply the concept of thresholds to conservation decisions. Here, we advocate a framework for thinking about thresholds in terms of a structured decision making process. The purpose of this framework is to promote a logical and transparent process for making informed decisions for conservation.

Specification of such a framework leads naturally to consideration of definitions and roles of different kinds …

Does The Mg/Ca In Foraminifera Tests Provide A Reliable Temperature Proxy?, Sarah Clark, Figen Mekik

Student Summer Scholars Manuscripts

The Mg/Ca in foraminifera shells is commonly used as a proxy to estimate ocean temperatures in Earth’s past. However, studies have shown that both dissolution and salinity influence the Mg/Ca in shells of tropical foraminifera, which can cause paleotemperature estimates to be inaccurate. We measured Mg/Ca in shells of Globigernoides ruber and Globigerinoides sacculifer from core tops in the eastern equatorial Pacific. We compared our results with global core top data, which paleotemperature equations have been calibrated and published. We find that Mg/Ca values range greatly at the same surface ocean temperature. We also find that salinity and dissolution do …

Structured Decision Making As A Conceptual Framework To Identify Thresholds For Conservation And Management, Julien Martin, Michael C. Runge, James D. Nichols, Bruce C. Lubow, William L. Kendall2

United States Geological Survey: Staff Publications

Threshold and their relevance to conservation have become a major topic of discussion in the ecological literature. Unfortunately, in many cases the lack of a clear conceptual framework for thinking about thresholds in terms of a structured decision making process. The purpose of this framework is to promote a logical and transparent process for making informed decisions for conservation.

Specification of such a framework leads naturally to consideration of definitions and roles of different kinds of thresholds in the process. We distinguish among three categories of thresholds. Ecological thresholds are values of system state variables at which small changes bring …

Riparian And Associated Habitat Characteristics Related To Nutrient Concentrations And Biological Responses Of Small Streams In Selected Agricultural Areas, United States, 2003–04, Ronald B. Zelt, Mark D. Munn

United States Geological Survey: Publications

Physical factors, including both in-stream and riparian habitat characteristics that limit biomass or otherwise regulate aquatic biological condition, have been identified by previous studies. However, linking the ecological significance of nutrient enrichment to habitat or landscape factors that could allow for improved management of streams has proved to be a challenge in many regions, including agricultural landscapes, where many ecological stressors are strong and the variability among watersheds typically is large. Riparian and associated habitat characteristics were sampled once during 2003–04 for an intensive ecological and nutrients study of small perennial streams in five contrasting agricultural landscapes across the United …

Behavior And Reproductive Success Of Rock Sandpipers Breeding On The Yukon-Kuskokwim River Delta, Alaska, Matthew Johnson, Jesse R. Conklin, Branden L. Johnson, Brian J. Mccaffery, Susan M. Haig, Jeffrey R. Walters

United States Geological Survey: Staff Publications

We studied Rock Sandpiper (Calidris ptilocnemis) breeding behavior and monitored reproductive success from 1998 to 2005 on the Yukon-Kuskokwim River Delta, Alaska, USA. We banded 24 adults and monitored 45 nests. Annual return rate of adults ranged between 67 and 100%. Six pairs of Rock Sandpipers bred at our study site for ≥ 2 years, and among these we did not observe mate change (i.e., when both members of a pair returned and each mated with a new individual). Nests were typically initiated by mid-May and 53% of females laid second clutches if first clutches were lost through …

The Neoglacial Landscape And Human History Of Glacier Bay, Glacier Bay National Park And Preserve, Southeast Alaska, Usa, Cathy Connor, Greg Streveler, Austin Post, Daniel Monteith, Wanye Howell

United States Geological Survey: Staff Publications

The Neoglacial landscape of the Huna Tlingit homeland in Glacier Bay is recreated through new interpretations of the lower Bay’s fjordal geomorphology, late Quaternary geology and its ethnographic landscape. Geological interpretation is enhanced by 38 radiocarbon dates compiled from published and unpublished sources, as well as 15 newly dated samples. Neoglacial changes in ice positions, outwash and lake extents are reconstructed for c. 5500–200 cal. yr ago, and portrayed as a set of three landscapes at 1600–1000, 500–300 and 300–200 cal. yr ago. This history reveals episodic ice advance towards the Bay mouth, transforming it from a fjordal seascape into …

Radiocarbon Date List Xi: Radiocarbon Dates From Marine Sediment Cores Of The Iceland, Greenland, And Northeast Canadian Arctic Shelves And Nares Strait, U. Quillmann, J.T. Andrews, A.E. Jennings, J. Bendle, H. Jonsdottir, G.B. Kristjansdottir, J. Lloyd, S. Olafsdottir, Sarah M. Principato

Environmental Studies Faculty Publications

Radiocarbon Date List XI contains an annotated listing of 178 AMS radiocarbon dates on samples from marine (169 samples) and lake (9 samples) sediment cores. Marine sediment cores, from which the samples for dating were taken, were collected on the Greenland Shelf, Baffin Bay, and the Eastern Canadian Arctic shelf. About 80% of the marine samples for dating were collected on the SW to N Icelandic shelf. The lake sediment cores were collected in northwestern Iceland. For dating of the marine samples, we submitted molluscs (117 samples), benthic and planktic foraminifera (45 samples), plant macrofauna (3 samples), and one serpulid …

Review Of Hard Road West: History And Geology Along The Gold Rush Trail By Keith Heyer Meldahl, Harmon D. Maher Jr.

Geography and Geology Faculty Publications

The dust jacket of Hard Road West promises familiar pleasures to John McPhee lovers, and so I picked the book up with great anticipation. McPhee’s works have greatly heightened the interest of writers and readers in the genre of creative nonfiction, and while for me, Keith Meldahl’s work does not quite reach McPhee’s stratospheric heights, for the right audience it is definitely a very good read.

Using Gis To Quantify Patterns Of Glacial Erosion On Northwest Iceland: Implications For Independent Ice Sheets, Sarah M. Principato, Jeremiah S. Johnson

Environmental Studies Faculty Publications

Glacial erosion patterns on northwest Iccliind are quantified using a Geographic Information System (GIS) in order to interpret subglacial characteristics of part of northwest Iceland affected by ice sheet glaciation. Ice scour lake density is used as a proxy for glacial erosion. Erosion classes are interpreted from variations in the density of lake basins. Lake density was calculated using two dilTerent methods: the first is sensitive to the total number of lakes in a specific area, and the second is sensitive to total lake area in a specific area. Both of these methods result in a value for lake density, …

A Computational Study Of Tsunami Runup As A Function Of Coastline Morphology, Kevin Ewell

Undergraduate Honors Theses

Tsunamis are surface waves with wavelengths on the order of tens to hundreds of kilometers. Modeling the propagation of a tsunami as it approaches shore requires detailed knowledge of bathymmetry in order to correctly capture the evolution of the wave as it slows down. Most published studies of terminal tsunami behavior (such as wave height and runup) are done for specific sites, often comparing model "postdictions" to recorded events. The goal of the present study is to understand in a general way how coastline indentations (such as bays and inlets) affect tsunami runup and wave height. The COMCOT tsunami propagation …

Processes Controlling Magma Chamber Evolution Beneath Mt. Rainier, Washington, Sean Ross Scott

Undergraduate Honors Theses

Mt. Rainier is an active composite volcano located in the Cascade volcanic arc, ~90km southeast of Seattle, Washington. Based on a compilation of data representing basaltic andesites through dacites, thermodynamic simulations have been run to constrain the mechanisms of formation of the typical liquid line of descent. Using a variety of parental magmas and iterating through parameters such as water content, pressure, and oxygen fugacity, the best fit models suggest magmas are stored at shallow levels and have initial water contents of~ 1-2.0 wt. % and oxygen fugacity of ~QFM+ 1 to +2. One lava flow, classified as a spessartite, …

Cave Minerals Of San Salvador Island, Bahamas, Bogdan P. Onac, Jonathan Sumrall, John E. Mylroie, Joe B. Kearns

Environmental Sustainability Books

This volume describes the results of a 2009 fieldwork season focusing on the cave minerals found in karst environments throughout San Salvador Island in the Bahamian archipelago. The caves visited represent a sampling of pit and flank margin caves. Each cave description includes a map.

Magma In A Beaker: Analog Experiments With Water And Various Salts Or Sugar For Teaching Igneous Petrology, John B. Brady

Geosciences: Faculty Publications

Solutions of water and a salt or sugar make excellent experimental analog magmas for teaching concepts of igneous petrology because of the comparatively low temperatures involved, the simplicity of the apparatus needed, and the responsiveness of familiar chemical systems. Boiling of these aqueous solutions on a hot plate can be used to increase the concentration of a dissolved salt or sugar to levels that may be predicted by steam-saturation curves. Sufficiently concentrated solutions will crystallize, partially or completely, upon cooling to room temperature. Binary temperature–composition phase diagrams for H₂O and KCl, NaCl, MgCl₂, CaCl₂, …

Crustal Modification By Tectonic Events And Upper Mantle Anisotropy Beneath The Midcontinent Rift And New Madrid Seismic Zone: Insights From Receiver Function Studies And Teleseismic Shear Wave Splitting, Moikwathai Moidaki

Doctoral Dissertations

"The earth's crust and upper mantle have been continually modified by tectonic processes such as rifting, earthquake activity. In this dissertation, shear wave splitting and receiver function techniques were employed to study the extent of crustal and upper mantle modifications beneath the New Madrid Seismic Zone (NMSZ) and the Midcontinent Rift (MCR). Shear wave splitting analysis in the MCR reveals the presence of fossilised anisotropy along the rift axis...In the NMSZ, anticipated rift-parallel fast directions associated with vertical magmatic dikes or along-rift flow, rift-orthogonal fast directions from small-scale convection, or reduction in splitting times as a result of vertical asthenospheric …

The Cretaceous-Paleogene Transition In The Northern Mississippi Embayment, S.E. Missouri: Palynology, Micropaleontology, And Evidence Of A Mega-Tsunami Deposit, Tambra L. Eifert

Doctoral Dissertations

"Upper Cretaceous to lower Paleogene sedimentary rocks in Southeastern Missouri record the northwest extension of the Mississippi Embayment, yet very little information exists about them due to lack of exposures. Access to borehole and trench material and well logs provided an opportunity to study the sedimentology, palynology and micropaleontology of the three formations spanning the Cretaceous-Paleogene (K-Pg) boundary interval: Owl Creek (Cretaceous) and Clayton and Porters Creek (Paleocene). Lithologic features, palynomorphs (mainly spores, pollen, dinoflagellate cysts), dispersed organic matter, and foraminifera were used to interpret biostratigraphy, paleovegetation, paleoclimatic and depositional conditions, thereby creating a framework upon which further questions involving …

Influences Of Channel Dredging On Flow And Sedimentation Patterns At Microtidal Inlets, West-Central Florida, Usa, Tanya M. Beck, Ping Wang

Geology Faculty Publications

Four inlets (Johns Pass and Blind Pass; and New Pass and Big Sarasota Pass) in two multi-inlet systems along the West-central Florida coast were studied. Johns Pass, New Pass, and Blind Pass are dredged every 4-9 years, whereas Big Sarasota Pass has never been dredged. The goal of this study was to investigate the morphodynamics of the four inlets and the influences of channel dredging on the flow patterns over the ebb tidal delta and sediment bypassing. Time-series aerial photographs and bathymetric maps starting from the 1920s were analyzed to assess the pathways of sand bypassing and morphodynamics at the …

The Mississippian Section At Paddys Bluff, Crittenden County, Kentucky, Ron Counts, F. Brett Denny, James C. Hower, Zakaria Lasemi, Rodney D. Norby, Paul E. Potter, Scott Waninger, David A. Williams

Map and Chart--KGS

Paddys Bluff (Figs. 1-3) is located on the south side of the Illinois Basin on the Cumberland River, 1.7 miles downstream from Dycusburg in Crittenden County, Ky., in Carter coordinate section 23-I-16 and ecoregion 71f of the Western Highland Rim of Kentucky (Woods and others, 2002). This bluff is on a right-descending bend 18 liver miles above its junction with the Ohio River at Smithland, Livingston County. The bluff (Figs. 4A, B) is locally famous as the location for a scene from the classic 1962 film, "How the West Was Won,' a winner of three Academy Awards, starling James Stewart, …

Four Rivers Basin: Cumberland, Tennessee, Ohio, Mississippi, Daniel I. Carey

Map and Chart--KGS

The Four Rivers Basin includes over 4 ,700 square miles in all or parts of 17 counties. The basin contains more than 10,700 miles of streams.

More than 720 miles of streams assessed in the basin by the Kentucky Division of Water do not support designated uses for warm-water aquatic habitat, fish consumption, primary contact recreation, or secondary contact recreation. Not all streams have been assessed. The percentage of assessed streams not supporting uses was: warm-water aquatic habitat (58 percent); fish consumption (14 percent); primary contact recreation (76 percent); secondary contact recreation (30 percent). Nearly 125 miles of streams have …

Upper Cumberland River Basin In Kentucky, Daniel I. Carey

Map and Chart--KGS

The Upper Cumberland River Basin covers over 7,300 square miles, 5,180 in Kentucky and 2,130 in Tennessee. All or parts of 20 Kentucky counties lie in the basin. The basin contains nearly 15,100 miles of streams, 10,430 in Kentucky and 4,640 in Tennessee. From the headwaters of Looney Creek in Harlan County, 4,100 feet above sea level, and the Poor Fork in Letcher County, runoff flows down the Upper Cumberland River west to an elevation of 460 feet at the Kentucky-Tennessee line. The river and its tributaries are a blessing and a bane: They provide for recreation, drinking water, and …