Oceanography and Atmospheric Sciences and Meteorology Commons^™

Quaternary Sea-Level History Of The United States, Daniel R. Muhs, John F. Wehmiller, Kathleen R. Simmons, Linda L. York

United States Geological Survey: Staff Publications

In the past 30 years, there have been tremendous advances in our understanding of Quaternary sea-level history, due directly to developments in Quaternary dating methods, particularly uranium-series disequilibrium and amino acid racemization. Another reason for this progress is that coastline history can now be tied to the oxygen-isotope record of foraminifera in deep-sea cores. Furthermore, both records have been linked to climate change on the scale of glacial-interglacial cycles that are thought to be forced by changes in Earth-Sun geometry, or “orbital forcing” (Milankovitch, 1941).

An Investigation Of Dissolved Organic Matter In A Shallow Coastal Bay Subject To Aureococcus Anophagefferens Blooms, Jean-Paul Simjouw

OES Theses and Dissertations

Aureococcus anophagefferens, the pelagophyte responsible for brown tide blooms, was identified in Chincoteague Bay in 1997 and has “bloomed” there since at least 1998. Aureococcus anophagefferens is capable of using dissolved organic nitrogen (DON) and dissolved organic carbon (DOC) substrates to support growth, and this utilization is hypothesized to give the organism a competitive advantage relative to other phytoplankton when inorganic nutrient concentrations are low or depleted. Because previous studies suggest dissolved organic matter (DOM) is important in initiating and sustaining brown tide blooms, a field study of the variations in DOC concentration and DOM composition was performed at …

A Modeling Experiment On The Grounding Of An Ice Shelf In The Central Arctic Ocean During Mis 6, Martin Jakobsson, M Siegert, Mark Paton

Center for Coastal and Ocean Mapping

High-resolution chirp sonar subbottom profiles from the Lomonosov Ridge in the central Arctic Ocean, acquired from the Swedish icebreaker Oden in 1996, revealed large-scale erosion of the ridge crest down to depths of 1000 m below present sea level [Jakobsson, 1999]. Subsequent acoustic mapping during the SCICEX nuclear submarine expedition in 1999 showed glacial fluting at the deepest eroded areas and subparallel ice scours from 950 m water depth to the shallowest parts of the ridge crest [Polyak et al., 2001]. The directions of the mapped glaciogenic bed-forms and the redeposition of eroded material on the Amerasian side of the …

Ancient Maize From Chacoan Great Houses: Where Was It Grown?, Larry Benson, Linda Cordell, Kirk Vincent, Howard E. Taylor, John Stein, G. Lang Farmer, U.S. Geological Survey

United States Geological Survey: Staff Publications

In this article, we compare chemical (⁸⁷Sr/⁸⁶Sr and elemental) analyses of archaeological maize from dated contexts within Pueblo Bonito, Chaco Canyon, New Mexico, to potential agricultural sites on the periphery of the San Juan Basin. The oldest maize analyzed from Pueblo Bonito probably was grown in an area located 80 km to the west at the base of the Chuska Mountains. The youngest maize came from the San Juan or Animas river floodplains 90 km to the north. This article demonstrates that maize, a dietary staple of southwestern Native Americans, was transported over considerable distances in …

Day 3. Wednesday, August 13, 2003: Coalbed Methane Development, University Of Colorado Boulder. Natural Resources Law Center

Energy Field Tour 2003 (August 11-16)

10 pages (includes color illustrations and maps).

Agenda: Energy Field Tour 2003, University Of Colorado Boulder. Natural Resources Law Center

Energy Field Tour 2003 (August 11-16)

Congressional staff tour held August 11-16, 2003

Summary: Binder of assorted articles, maps, brochures and other materials prepared for participants of the tour

Contents:

MONDAY, AUGUST 11, 2003: BLUE SPRUCE PEAKER PLANT: University of Colorado Natural Resources Law Center : congressional staff tour of Blue Spruce Energy Center / Peggy Duxbury -- 'Power Struggle', National Journal, June 27, 2003 / Margaret Kritz -- 'Calpine's Blue Spruce Energy Center begins commercial operation', Calpine press release, April 17, 2003 -- NATIONAL RENEWABLE ENERGY LAB: NREL at a glance -- NREL technologies -- SHOSHONE HYDROELECTRIC PLANT: 'River District Board supports spring Shoshone call …

Day 1. Monday, August 11, 2003: Shoshone Hydroelectric Plant, Glenwood Canyon, Shoshone Hydroelectric Plant

Energy Field Tour 2003 (August 11-16)

3 pages.

Contains references.

Mid-Holocene Climates Of The Americas: A Dynamical Response To Changed Seasonality, S. P. Harrison, J. E. Kutzbach, Z. Liu, P. J. Bartlein, B. Otto-Bliesner, Daniel R. Muhs, I. C. Prentice, R. S. Thompson

United States Geological Survey: Staff Publications

Abstract Simulations of the climatic response to mid- Holocene (6 ka BP) orbital forcing with two coupled ocean–atmosphere models (FOAM and CSM) show enhancement of monsoonal precipitation in parts of the American Southwest, Central America and northernmost South America during Northern Hemisphere summer. The enhanced onshore flow that brings precipitation into Central America is caused by a northward displacement of the inter-tropical convergence zone, driven by cooling of the equatorial and warming of the northern subtropical and mid-latitude ocean. Ocean feedbacks also enhance precipitation over the American Southwest, although the increase in monsoon precipitation there is largely driven by increases …

Holocene Paleoflood Hydrology Of The Lower Deschutes River, Oregon, Kurt J. Hosman, Lisa L. Ely, Jim E. O'Connor

Student Published Works

Flood deposits at four sites along the lower Deschutes River, Oregon, were analyzed to determine magnitude and frequency of late Holocene flooding. Deposit stratigraphy was combined with hydraulic modeling at two sites to determine ranges of likely discharges for individual deposits. Combining these results with gaged flood data provides improved flood frequency estimates at the Axford site. The completeness and age spans of preserved flood chronologies differed among the four sites, but results were consistent for the largest floods of the last 5000 years. Single floods exceeded 2860-3800 mVs -4600 cal yr BP, 1060-1810 mVs -1300 cal yr BP, and …

New Evidence For Enhanced Ocean Primary Production Triggered By Tropical Cyclone, I. Lin, W. Timothy Liu, Chun-Chieh Wu, George T. F. Wong, Chuanmin Hu, Zhiqiang Chen, Wen-Der Liang, Yih Yang, Kon-Kee Liu

OES Faculty Publications

[1] New evidence based on recent satellite data is presented to provide a rare opportunity in quantifying the long-speculated contribution of tropical cyclones to enhance ocean primary production. In July 2000, moderate cyclone Kai-Tak passed over the South China Sea (SCS). During its short 3-day stay, Kai-Tak triggered an average 30-fold increase in surface chlorophyll-a concentration. The estimated carbon fixation resulting from this event alone is 0.8 Mt, or 2-4% of SCS's annual new production. Given an average of 14 cyclones passing over the SCS annually, we suggest the long-neglected contribution of tropical cyclones to SCS's annual new production may …

Methods And Models For Estimating Advective Pore Water Exchange In Tidal Flats, Timothy J. Shaw

Faculty Publications

No abstract provided.

Late-Holocene Climate And Ecosystem History From Chesapeake Bay Sediment Cores, Usa, Debra A. Willard, Thomas M. Cronin, Stacey Verardo

United States Geological Survey: Staff Publications

Palaeoclimate records from late-Holocene sediments in Chesapeake Bay, the largest estuary in the USA, provide evidence that both decadal to centennial climate variability and European colonization had severe impacts on the watershed and estuary. Using pollen and dinoflagellate cysts as proxies for mid-Atlantic regional precipitation, estuarine salinity and dissolved oxygen (DO) during the last 2300 years, we identified four dry intervals, centred on ad 50 (P1/D1), ad 1000 (P2/D2), ad 1400 (P3) and ad 1600 (P4). Two centennial-scale events, P1/D1 and P2/D2, altered forest composition and led to increased salinity and DO levels in the estuary. Intervals P3 and P4 …

Calibration Of Remotely Sensed, Coarse Resolution Ndvi To Co2 Fluxes In A Sagebrush–Steppe Ecosystem, Bruce K. Wylie, Douglas A. Johnson, Emilio Laca, Nicanor Z. Saliendra, Tagir G. Gilmanov, Bradley C. Reed, Larry L. Tieszen, Bruce B. Worstell

United States Geological Survey: Staff Publications

The net ecosystem exchange (NEE) of carbon flux can be partitioned into gross primary productivity (GPP) and respiration (R). The contribution of remote sensing and modeling holds the potential to predict these components and map them spatially and temporally. This has obvious utility to quantify carbon sink and source relationships and to identify improved land management strategies for optimizing carbon sequestration. The objective of our study was to evaluate prediction of 14-day average daytime CO₂ fluxes ( F_day) and nighttime CO₂ fluxes (R_n) using remote sensing and other data. F_{day …}

An Approach For Mapping Large-Area Impervious Surfaces: Synergistic Use Of Landsat-7 Etm+ And High Spatial Resolution Imagery, Limin Yang, Chengquan Huang, Bruce K. Wylie, Michael J. Coan

United States Geological Survey: Staff Publications

A wide range of urban ecosystem studies, including urban climate, land use planning, and resource management, require current and accurate geospatial data of urban impervious surfaces. We developed an approach to quantify urban impervious surfaces as a continuous variable by using multisensor datasets. Subpixel percent impervious surfaces at 30-m resolution were mapped using a regression tree model. The utility, practicality, and affordability of the proposed method for large-area imperviousness mapping were tested over three spatial scales (Sioux Falls, South Dakota, Richmond, Virginia, and the Chesapeake Bay areas of the United States). Average error of predicted versus actual percent impervious surface …

Influence Of The Pacific Decadal Oscillation On The Climate Of The Sierra Nevada, California And Nevada, Larry Benson, Braddock Linsley, Joe Smoot, Scott Mensing, Steve Lund, Scott Stine, Andre Sarna-Wojcicki

United States Geological Survey: Staff Publications

Mono Lake sediments have recorded five major oscillations in the hydrologic balance between A.D. 1700 and 1941. These oscillations can be correlated with tree-ring-based oscillations in Sierra Nevada snowpack. Comparison of a tree-ring-based reconstruction of the Pacific Decadal Oscillation (PDO) index (D’Arrigo et al., 2001) with a coral-based reconstruction of Subtropical South Pacific sea-surface temperature (Linsley et al., 2000) indicates a high degree of correlation between the two records during the past 300 yr. This suggests that the PDO has been a pan-Pacific phenomena for at least the past few hundred years. Major oscillations in the hydrologic balance of the …

Age Of The Mono Lake Excursion And Associated Tephra, Larry Benson, Joseph Liddicoat, Joseph Smoot, Andrei Sarna-Wojcicki, Robert M. Negrini, Steve Lund

United States Geological Survey: Staff Publications

The Mono Lake excursion (MLE) is an important time marker that has been found in lake and marine sediments across much of the Northern Hemisphere. Dating of this event at its type locality, the Mono Basin of California, has yielded controversial results with the most recent effort concluding that the MLE may actually be the Laschamp excursion (Earth Planet. Sci. Lett. 197 (2002) 151). We show that a volcanic tephra (Ash #15) that occurs near the midpoint of the MLE has a date (not corrected for reservoir effect) of 28,620 ± 300 ¹⁴C yr BP (~32,400 GISP2 yr BP) …

Rare-Earth Elements And Nd And Pb Isotopes As Source Indicators For Labrador Sea Clay-Size Sediments During Heinrich Event 2, Larry V. Benson, Don Barber, John T. Andrews, Howard E. Taylor, Paul Lamothe

United States Geological Survey: Staff Publications

Elemental abundances and Nd and Pb isotope ratios were determined on samples from the carbonate-free, clay-size fractions of sediments from intervals above, within, and below Heinrich event 2 (H-2) in core HU87-9 from the Northwest Labrador Sea slope. In HU87-9, rare-earth element (REE) distributions and elemental concentrations within the H-2 event are distinct from those outside this event. ɛ_Nd(0) and ²⁰⁶Pb/²⁰⁴Pb data also indicate different values for sediments deposited within and outside the H-2 event. Comparisons of REE patterns from the H-2 interval with those from bedrock units in Baffin Island, northern Quebec, and Labrador …

Response Of North American Great Basin Lakes To Dansgaard–Oeschger Oscillations, Larry Benson, Steve Lund, Robert M. Negrini, Braddock Linsley, Mladen Zic

United States Geological Survey: Staff Publications

We correlate oscillations in the hydrologic and/or cryologic balances of four Great Basin surface-water systems with Dansgaard– Oeschger (D–O) events 2–12. This correlation is relatively strong at the location of the magnetic signature used to link the lake records, but becomes less well constrained with distance/time from the signature. Comparison of proxy glacial and hydrologic records from Owens and Pyramid lakes indicates that Sierran glacial advances occurred during times of relative dryness. If our hypothesized correlation between the lake-based records and the GISP2 δ¹⁸O record is correct, it suggests that North Atlantic D–O stades …

Aeolian Cliff-Top Deposits And Buried Soils In The White River Badlands, South Dakota, Usa, J. Elmo Rawling Iii, Glen G. Fredlund, Shannon Mahan

United States Geological Survey: Staff Publications

Aeolian deposits in the North American Great Plains are important sources of Holocene palaeoenvironmental records. Although there are extensive studies on loess and dune records in the region, little is known about records in aeolian cliff-top deposits. These are common on table (mesa) edges in the White River Badlands. These sediments typically have loam and sandy-loam textures with dominantly very fine sand, 0.5–1% organic carbon and 0.5–5% CaCO₃. Some of these aeolian deposits are atypically coarse and contain granules and fine pebbles. Buried soils within these deposits are weakly developed with A-C and A-AC-C profiles. Beneath these are …

New Record Of The Rare Emballonurid Bat Centronycteris Centralis Thomas, 1912 In Costa Rica, With Notes On Feeding Habits, Neal Woodman

United States Geological Survey: Staff Publications

The shaggy sac-winged bat, Centronycteris centralis (Chiroptera: Emballonuridae), occurs mainly in lowland forests from Veracruz, Mexico, to Peru, although it has been reported from elevations as high at 1450 m in Panama (Simmons and Handley 1998; Hice and Solari 2002). Most captures of the species are of single individuals, and throughout its distribution, this bat is rare and poorly-known (Emmons 1997; Reid 1997; Simmons and Handley 1998). Centronycteris centralis generally has been assumed to be an aerial insectivore, capturing flying insects on the wing (Starrett and Casebeer 1968; Wilson 1973; Timm et al. 1989; LaVal and Rodrı´guez 2002). However, direct …

Quaternary Loess-Paleosol Sequences As Examples Of Climate-Driven Sedimentary Extremes, Daniel R. Muhs, E. Arthur Bettis Iii

United States Geological Survey: Staff Publications

Loess is a widespread, wind-transported, silt-dominated deposit that contains geologic archives of atmospheric circulation and paleoclimate on continents. Loess may cover as much as 10% of the Earth’s land surface. It is composed mainly of quartz, feldspars, and clay minerals, with varying amounts of carbonate minerals. The geochemistry of loess differs from region to region, depending on source materials, but all loess is very high in SiO2 with lesser amounts of other major elements. Trends in loess downwind from source areas include systematic decreases in thickness and amounts of sand and coarse silt, and increases in amounts of fine silt …

Seafloor Characterization From Spatial Variation Of Multibeam Backscatter Vs."Best Estimated" Grazing Angle, Tianhang Hou, Larry A. Mayer, Christian De Moustier, Barbara J. Kraft

Center for Coastal and Ocean Mapping

Backscatter vs. grazing angle, which can be extracted from multibeam backscatter data, depends on characteristics of the multibeam system and the angular responses of backscatter that are characteristic of different seafloor properties, such as sediment hardness and roughness. Changes in backscatter vs. grazing angle that are contributed by the multibeam system normally remain fixed over both space and time. Therefore, they can readily be determined and removed from backscatter data. The component of backscatter vs. grazing angle due to the properties of sediments varies from location to location, as the sediment changes. The sediment component of variability can be inferred …

A 700-Year Record Of Atmospheric Circulation Developed From The Law Dome Ice Core, East Antarctica, Joseph M. Souney Jr, Paul A. Mayewski, Ian D. Goodwin, David Meeker, Vin Morgan, Mark Aj Curran, Tas D. Van Ommen, Anne S. Palmer

All Materials

A 700-year, high-resolution, multivariate ice core record from Dome Summit South (DSS) (66°46′S, 112°48′E; 1370 m), Law Dome, is used to investigate sea level pressure (SLP) variability in the region of East Antarctica. Empirical orthogonal function (EOF) analysis reveals that the first EOF (LDEOF1) of the combined glaciochemical, oxygen isotope ratio, and accumulation rate record from DSS represents most of the variability in sea salt seen in the record. LDEOF1 is positively correlated (at least 95% confidence level) to instrumental June mean SLP across most of East Antarctica. Over the last 700 years, LDEOF1 levels at Law Dome were the …

Field Guide To The Geology Of The Harlan County Lake Area, Harlan County, Nebraska, With A History Of Events Leading To Construction Of Harlan County Dam, Robert F. Diffendal Jr., Duane R. Mohlman, R. George Corner, F. Edwin Harvey, K. J. Warren, Scott Summerside, Roger K. Pabian, Duane A. Eversoll

School of Natural Resources: Faculty Publications

The year 2002 will mark the fiftieth anniversary of completion of the Harlan County Dam and Multi-Purpose Reservoir. This seems a good time to write about the history of and reasons for building the dam, the effects of the dam and reservoir on the Republican River valley, and the geologic features seen along the shores of the lake and areas nearby. As many junior authors helped produced this educational circular, they are listed in the table of contents. All other sections were written by the senior author.

Includes July 2016 update: Addendum of photographs showing fault traces on drought-exposed lake …

Beginning A New Era Of Drought Monitoring Across North America, Jay Lawrimore, Richard R. Heim Jr., Mark D. Svoboda, Val Swail, Phil J. Englehart

National Drought Mitigation Center: Faculty Publications

Drought experts from the United States, Canada, and Mexico met at the National Climatic Data Center in Asheville, North Carolina, for a three-day workshop in late April 2002 to discuss the United States Drought Monitor program and to develop a plan for initiating a new program of drought monitoring for North America. Since its inception in 1999, the U.S. Drought Monitor (DM) has been extremely successful in assessing and communicating the state of drought in the United States on a weekly basis. This success, and the recognition that an ongoing comprehensive and integrated drought assessment was needed throughout all three …

Organic Geochemical Analysis Of Late-Glacial And Early-Holocene Ecosystem Changes: A Case Study From Northern New England Lakes, Michael A. Kruge, Andrea Lini

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The lacustrine sedimentary archive of organic remains provides important evidence for the reconstruction of the environmental histories of lakes and their watersheds, recording the response of the Earth's biota to changes on scales varying from the local to the global. The last Glacial-Interglacial transition presents an opportunity to investigate how, and at what rates, watershed and lake ecosystems were established on once glaciated, carbon and nutrient-poor landscapes. The small lakes of northern Vermont (USA) provide an appropriate setting in which to investigate such changes.

As part of a multidisciplinary study of three Vermont lake sediment cores, samples ranging in age …

The Drought Monitor, Mark D. Svoboda, Doug Lecomte, Mike Hayes, Richard Heim, Karin Gleason, Jim Angel, Brad Rippey, Rich Tinker, Mike Palecki, David Stooksbury, David Miskus, Scott Stephens

National Drought Mitigation Center: Faculty Publications

There is a need for improved drought monitoring and assessment methods in the United States. Drought is the most costly natural disaster [Federal Emergency Management Agancy (FEMA 1995; Wilhite 2000)], but it is often neglected by developers of assessment and forecast products. Drought is more nebulous than other disasters and does not lend itself to traditional assessments or forecast methods. Its relatively slow onset and the complexity of its impacts are reasons for the new assessment methodology. Improvements in drought monitoring and forecasting techniques will allow for better preparation, lead to better management practices, and reduce the vulnerability of society …

Soil Leachate Responses During 10 Years Of Induced Whole-Watershed Acidification, Pamela J. Edwards, James N. Kochenderfer, Dean W. Coble, Mary Beth Adams

Faculty Publications

Soil solution was collected from zero-tension lysimeters for 10 yr on two small central Appalachian watersheds in West Virginia, U.S.A. Ammonium sulfate fertilizer was applied to one catchment 3 times per year during each year. The other watershed was used as a reference to account for ambient baseline conditions. Ca and Mg concentrations collected below the A- and B-horizons of the treated watershed increased and then decreased over time as a result of the treatment. By contrast, Ca and Mg concentrations in the C-horizon continued to increase throughout the study period.

Rates Of Sedimentation In The Central Arctic Ocean, Jan Backman, Martin Jakobsson, Reidar Lovlie, Leonid Polyak

Center for Coastal and Ocean Mapping

The Arctic Ocean is presently undergoing geoscientific investigations of the type that occurred during the late 1940's through 1960's in the Atlantic, Indian and Pacific oceans. Seismic reflection and refraction data are scarce in the Arctic Ocean and large areas are virtually unsampled with respect to piston or gravity coring. The vast majority of available cores are less than10 m in length and largely lack biostratigraphically useful calcareous and siliceous microfossils. No drill cores exist from the ridges or deep basins in the central Arctic Ocean. Considering the limited geophysical and geological data available, it is not surprising that current …

Land Use Change And Modification Of Near-Surface Thermal Records In The Northern Great Plains, Rezaul Mahmood, Ken Hubbard, Christy Carlson

High Plains Regional Climate Center: Staff Publications

The North American Great Plains have experienced a rapid overturning of natural grasslands to agricultural land use over the last century. Moreover, in some areas more than 80% of the land use has changed from dry land to irrigated agriculture during the second half of the twentieth century. It is speculated that these changes have modified near-surface atmospheric condition and our modeling study seems to support this. To identify changes in land surface- atmospheric modifications we have applied a soil moistureenergy balance model at three locations in Nebraska: Mead, York, and McCook. The model was applied for three land uses …