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2003

Oceanography and Atmospheric Sciences and Meteorology

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Articles 1 - 30 of 241

Full-Text Articles in Physical Sciences and Mathematics

Collaborative Research: Origins Of Cods On Georges Bank: Contributions Of Early Developmental Stages For The Scotian Shelf, David W. Townsend, Irv Kornfield, Linda Kling Dec 2003

Collaborative Research: Origins Of Cods On Georges Bank: Contributions Of Early Developmental Stages For The Scotian Shelf, David W. Townsend, Irv Kornfield, Linda Kling

University of Maine Office of Research Administration: Grant Reports

Recent work in the Georges Bank-Gulf of Maine area has documented significant, and apparently episodic, fluxes of Scotian Shelf Water (SSW) from the Nova Scotian continental shelf to Georges Bank. SSW is a relatively cold and fresh water mass with a significant component from the St. Lawrence River, and is commonly identifiable with temperature-salinity analyses of hydrographic data and in satellite images of sea surface temperature. One such flux episode was observed last March (1997) in satellite imagery and from shipboard hydrographic sampling on Georges Bank. Qualitative at-sea analyses of ichthyoplankton sampled on the March cruise revealed a remarkably tight …


Breaking Of Thunderstorm-Generated Gravity Waves As A Source Of Short-Period Ducted Waves At Mesopause Altitudes, Jonathan B. Snively, Victor P. Pasko Dec 2003

Breaking Of Thunderstorm-Generated Gravity Waves As A Source Of Short-Period Ducted Waves At Mesopause Altitudes, Jonathan B. Snively, Victor P. Pasko

Publications

Numerical simulation results indicate that the breaking of atmospheric gravity waves generated by tropospheric convection can excite short-period secondary waves, which are trapped in the lower thermospheric duct and which closely resemble quasi-monochromatic structures commonly observed in airglow imaging experiments.


Swine Waste Demonstration And Training Project, C. V. Maxwell, K. Vandevender, K. P. Coffey, P. A. Moore, I. Chaubey, D. R. Smith Dec 2003

Swine Waste Demonstration And Training Project, C. V. Maxwell, K. Vandevender, K. P. Coffey, P. A. Moore, I. Chaubey, D. R. Smith

Technical Reports

No abstract provided.


A Modeling Experiment On The Grounding Of An Ice Shelf In The Central Arctic Ocean During Mis 6, Martin Jakobsson, M Siegert, Mark Paton Dec 2003

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 …


The Extratropical Transition Of Tropical Cyclones: Forecast Challenges, Current Understanding, And Future Directions, Sarah C. Jones, Patrick A. Harr, Jim Abraham, Lance F. Bosart, Peter J. Bowyer, Jenni L. Evans, Deborah E. Hanley, Barry N. Hanstrum, Robert E. Hart, Francois Lalaurette, Mark R. Sinclair, Roger K. Smith, Chris Thorncroft Dec 2003

The Extratropical Transition Of Tropical Cyclones: Forecast Challenges, Current Understanding, And Future Directions, Sarah C. Jones, Patrick A. Harr, Jim Abraham, Lance F. Bosart, Peter J. Bowyer, Jenni L. Evans, Deborah E. Hanley, Barry N. Hanstrum, Robert E. Hart, Francois Lalaurette, Mark R. Sinclair, Roger K. Smith, Chris Thorncroft

Applied Aviation Sciences - Prescott

A significant number of tropical cyclones move into the midlatitudes and transform into extratropical cyclones. This process is generally referred to as extratropical transition (ET). During ET a cyclone frequently produces intense rainfall and strong winds and has increased forward motion, so that such systems pose a serious threat to land and maritime activities. Changes in the structure of a system as it evolves from a tropical to an extratropical cyclone during ET necessitate changes in forecast strategies. In this paper a brief climatology of ET is given and the challenges associated with forecasting extratropical transition are described in terms …


Reviewed Work(S): Electronic Tagging And Tracking In Marine Fisheries., David W. Kerstetter Dec 2003

Reviewed Work(S): Electronic Tagging And Tracking In Marine Fisheries., David W. Kerstetter

Marine & Environmental Sciences Faculty Articles

No abstract provided.


Case 3270: Isometrinae Clark, 1917 (Ecinodermata, Crinoidea): Proposed Emendation Of Spelling To Isometrainae To Remove Homonymy With Isometrinae Kraepelin, 1891 (Arachnida, Scorpiones), Victor Fet, Charles G. Messing Dec 2003

Case 3270: Isometrinae Clark, 1917 (Ecinodermata, Crinoidea): Proposed Emendation Of Spelling To Isometrainae To Remove Homonymy With Isometrinae Kraepelin, 1891 (Arachnida, Scorpiones), Victor Fet, Charles G. Messing

Marine & Environmental Sciences Faculty Articles

The purpose of this application, under Articles 55 and 29 of the Code, is to remove the homonymy between the crinoid subfamily name ISOMETRINAE Clark, 1917 (type genus Isometra Clark, 1908; family ANTEDONIDAE) and the scorpion subfamily name ISOMETRINAE Kraepelin, 1891 (type genus Isometrus Ehrenberg in Hemprich & Ehrenberg, 1828; family BUTHIDAE). It is proposed that the entire generic name of Isometra should be adopted as the stem, so that the correct spelling of the crinoid subfamily will become ISOMETRAINAE Clark, 1917.


Analysis Of The Spatial Dynamics Of The American Lobster (Homarus Americanus) Fishery Along The Coast Of Maine, Kevin M. Scheirer Dec 2003

Analysis Of The Spatial Dynamics Of The American Lobster (Homarus Americanus) Fishery Along The Coast Of Maine, Kevin M. Scheirer

Electronic Theses and Dissertations

The American lobster (Homarus americanus) supports the most valuable commercial fishery in the northeastern United States, thus the fishery is critical to Maine's economy. No systematic study has been done to collect information about, identify, and quantify the spatial dynamics of the Maine lobster fishery. This project helps to provide a better understanding of Maine's lobster fishery dynamics, and it will aid f'iture efforts to improve the stock assessment of Maine's lobster fishery. The analysis consists of three distinct parts: (1) comparison of data collected by two separate fishery dependent sampling programs; (2) spatial analysis of electronic logbook data; and …


Specific Dynamic Action, Growth And Development In Larval Atlantic Cod, Gadus Morhua, Jessica A. Geubtner Dec 2003

Specific Dynamic Action, Growth And Development In Larval Atlantic Cod, Gadus Morhua, Jessica A. Geubtner

Electronic Theses and Dissertations

The larval stage of marine fish is a period of rapid growth and development. Atlantic cod (Gadus morhua) are approximately 4-5 rnm in length upon hatch and feed endogenously from their yolk sac for the first week. After this time, larval cod must successfully capture live prey to survive and to fuel high growth rates of greater than 10%d". Previous studies have found that during exogenous feeding and at growth rates greater than 8%d1 larvae experience what appears to be cost free growth, where mass specific metabolic rate does not decrease with increasing mass. Due to size and condition constraints …


Pond-Breeding Amphibian Species Distributions In A Beaver-Modified Landscape, Acadia National Park, Mount Desert Island, Maine, Jesse Cunningham Dec 2003

Pond-Breeding Amphibian Species Distributions In A Beaver-Modified Landscape, Acadia National Park, Mount Desert Island, Maine, Jesse Cunningham

Electronic Theses and Dissertations

In order to maintain pond-breeding amphibian species richness, it is important to understand how both natural and anthropogenic disturbances affect species assemblages and individual species distributions both at the scale of individual ponds and at a larger landscape scale. The goal of this project was to investigate what characteristics of ponds and the surrounding wetland landscape were most effective in predicting pond-breeding species richness and the individual occurrence of wood frog (Rana sylvatica), bullfrog (Rana catesbeiana) and pickerel frog (Rana palustris) breeding sites in a beaver-modified landscape and how this landscape has changed over …


The Role Of Larval Thermal Tolerance In The Distribution Of Blue Mussel Species Within The Gulf Of Maine, Susan J. Limbeck Dec 2003

The Role Of Larval Thermal Tolerance In The Distribution Of Blue Mussel Species Within The Gulf Of Maine, Susan J. Limbeck

Electronic Theses and Dissertations

Two species of blue mussel, Myrilus edulis and Myrilus trossulus, are sympatric throughout much of the Canadian Maritime Provinces and into the Gulf of Maine. While the distribution of M edulis extends south to the Mid-Atlantic, that of M. trossulus ends abruptly in the Gulf of Maine. I have hypothesized that these differences in adult distribution are the result of species-specific variation in larval thermal tolerances. Previously, it has been shown that when reared at 20 OC, from 36 hour post-fertilization through settlement, M. trossulus had significantly higher mortality rates than M. edulis. This study examined whether species-specific differences in …


An Investigation Of The Cumulative Impacts Of Shrimp Trawling On Mud Bottom Fishing Grounds In The Gulf Of Maine: Effects On Habitat And Macrofaunal Community Structure, Anne W. Simpson Dec 2003

An Investigation Of The Cumulative Impacts Of Shrimp Trawling On Mud Bottom Fishing Grounds In The Gulf Of Maine: Effects On Habitat And Macrofaunal Community Structure, Anne W. Simpson

Electronic Theses and Dissertations

Despite the widespread occurrence of trawl fisheries on mud-bottoms, there is limited knowledge concerning the effects of trawling induced disturbance on these habitats and their resident macrofaunal communities. I investigated the cumulative impacts of seasonal commercial shrimp trawling on infaunal habitat and macrofaunal community structure on two mud-bottom fishing grounds in the Gulf of Maine from June 2000 - December 2001. One fishing ground located near the Outer Pumpkin Ledges (Pumpkin) experienced trawling activity during the 2000-2001 fishing season. In contrast, the other fishing ground near Monhegan Island was not trawled during the same period because shrimp abundances were low. …


A Comparison Of The Ecological Integrity Of Headwater Streams Draining Harvested And Un-Harvested Watersheds In The Western Mountains Of Maine, U.S.A., Darlene Siegel Dec 2003

A Comparison Of The Ecological Integrity Of Headwater Streams Draining Harvested And Un-Harvested Watersheds In The Western Mountains Of Maine, U.S.A., Darlene Siegel

Electronic Theses and Dissertations

Physical, chemical, and biological characteristics of four headwater streams draining forested watersheds were compared to determine the effectiveness of Riparian Management Zones (RMZs) in protecting aquatic ecological integrity from the effects of forest harvesting. Two of the watersheds were harvested with a 30% sheltenvood cut and a 75 foot buffer was left adjacent to the streams. The other two watersheds were un-harvested and were used as reference conditions for comparison with the harvested watersheds. General environmental conditions in these four headwater streams during the study period were characterized as follows. Each stream was located within a mixed- wood forest dominated …


Age, Growth And The Annual Cycles Of Lipogenesis And Reproduction Of Acanthurus Bahianus In Southeastern Florida, Stacy M. Wolfe Dec 2003

Age, Growth And The Annual Cycles Of Lipogenesis And Reproduction Of Acanthurus Bahianus In Southeastern Florida, Stacy M. Wolfe

HCNSO Student Theses and Dissertations

The ocean surgeon, Acanthurus bahianus, is a coral reef fish inhabiting the tropical and subtropical waters of the western Atlantic, including southeastern Florida. This study was a 23-month analysis of the reproductive cycle correlated with the annual build up and depletion of fat reserves in the fish. In addition, an age and growth analysis of this species was conducted. A total of 507 fish were analyzed for length, weight, gonad weight and fat body weight. 478 were aged by microscopic examination of the transverse section of the sagittae otolith. The von Bertalannfy growth equation was used to determine length at …


Ams Radiocarbon Chronology Of Glacier Fluctuations In The South Shetland Islands During The Last Glacial/Interglacial Hemicycle:Implications For Global Climate Change, Brenda L. Hall Nov 2003

Ams Radiocarbon Chronology Of Glacier Fluctuations In The South Shetland Islands During The Last Glacial/Interglacial Hemicycle:Implications For Global Climate Change, Brenda L. Hall

University of Maine Office of Research Administration: Grant Reports

This award supports a two year program to produce a new reconstruction of ice extent, elevation and thickness at the Last Glacial Maximum (LGM) for the South Shetland Islands in the Antarctic Peninsula. One field season on Livingston Island will involve mapping the areal extent and geomorphology of glacial drift and determining the elevation and distribution of trimlines. In addition, ice flow direction will be determined by mapping and measuring the elevation of erosional features and the position of erratic boulders. One of the main goals of this work will be to demonstrate whether or not organic material suitable for …


Chemical And Physical Properties Of Bulk Aerosols Within Four Sectors Observed During Trace-P, C. Jordan, B E. Anderson, R. Talbot, Jack E. Dibb, H Fuelberg, Charlie Hudgins, C M. Kiley, R. S. Russo, Eric Scheuer, Garry Seid, K L. Thornhill, E L. Winstead Nov 2003

Chemical And Physical Properties Of Bulk Aerosols Within Four Sectors Observed During Trace-P, C. Jordan, B E. Anderson, R. Talbot, Jack E. Dibb, H Fuelberg, Charlie Hudgins, C M. Kiley, R. S. Russo, Eric Scheuer, Garry Seid, K L. Thornhill, E L. Winstead

Earth Sciences

Chemical and physical aerosol data collected on the DC-8 during TRACE-P were grouped into four sectors based on back trajectories. The four sectors represent long-range transport from the west (WSW), regional circulation over the western Pacific and Southeast Asia (SE Asia), polluted transport from northern Asia with substantial sea salt at low altitudes (NNW) and a substantial amount of dust (Channel). WSW has generally low mixing ratios at both middle and high altitudes, with the bulk of the aerosol mass due to non-sea-salt water-soluble inorganic species. Low altitude SE Asia also has low mean mixing ratios in general, with the …


Uptake Of Nitrate And Sulfate On Dust Aerosols During Trace-P, C. Jordan, Jack E. Dibb, B E. Anderson, H Fuelberg Nov 2003

Uptake Of Nitrate And Sulfate On Dust Aerosols During Trace-P, C. Jordan, Jack E. Dibb, B E. Anderson, H Fuelberg

Earth Sciences

Aerosol data collected near Asia on the DC-8 aircraft platform during TRACE-P has been examined for evidence of uptake of NO3 and SO4= on dust surfaces. Data is compared between a sector where dust was predominant and a sector where dust was less of an influence. Coincident with dust were higher mixing ratios of anthropogenic pollutants. HNO3, SO2, and CO were higher in the dust sector than the nondust sector by factors of 2.7, 6.2, and 1.5, respectively. The colocation of dust and pollution sources allowed for the uptake of NO3 …


Aerosol Chemical Composition In Asian Continental Outflow During The Trace-P Campaign: Comparison With Pem-West B, Jack E. Dibb, R. Talbot, Eric Scheuer, Garry Seid, Melody A. Avery, H B. Singh Nov 2003

Aerosol Chemical Composition In Asian Continental Outflow During The Trace-P Campaign: Comparison With Pem-West B, Jack E. Dibb, R. Talbot, Eric Scheuer, Garry Seid, Melody A. Avery, H B. Singh

Earth Sciences

Aerosol associated soluble ions and the radionuclide tracers 7Be and 210Pb were quantified in 414 filter samples collected in spring 2001 from the DC-8 during the Transport and Chemical Evolution over the Pacific (TRACE-P) campaign. Binning the data into near Asia (flights from Hong Kong and Japan) and remote Pacific (all other flights) revealed large enhancements of NO3, SO4=, C2O4=, NH4+, K+, Mg2+, and Ca2+ near Asia. The boundary layer and lower troposphere were most strongly influenced by continental …


Intercontinental Transport Of Pollution Manifested In The Variability And Seasonal Trend Of Springtime O3 At Northern Middle And High Latitudes, Yuhang Wang, Changsub Shim, Nicola J. Blake, D R. Blake, Yunsoo Choi, Brian Ridley, Jack E. Dibb, Anthony Wimmers, Jennie Moody, F Flocke, Andrew Weinheimer, R. Talbot, Elliot Atlas Nov 2003

Intercontinental Transport Of Pollution Manifested In The Variability And Seasonal Trend Of Springtime O3 At Northern Middle And High Latitudes, Yuhang Wang, Changsub Shim, Nicola J. Blake, D R. Blake, Yunsoo Choi, Brian Ridley, Jack E. Dibb, Anthony Wimmers, Jennie Moody, F Flocke, Andrew Weinheimer, R. Talbot, Elliot Atlas

Earth Sciences

Observations (0–8 km) from the Tropospheric Ozone Production about the Spring Equinox (TOPSE) experiment are analyzed to examine air masses contributing to the observed variability of springtime O3 and its seasonal increase at 40°–85°N over North America. Factor analysis using the positive matrix factorization and principal component analysis methods is applied to the data set with 14 chemical tracers (O3, NOy, PAN, CO, CH4, C2H2, C3H8, CH3Cl, CH3Br, C2Cl4, CFC-11, HCFC-141B, Halon-1211, and 7Be) and one …


Remote Sensing Of Sediment Characteristics By Optimized Echo-Envelope Matching, Daniel D. Sternlicht, Christian De Moustier Nov 2003

Remote Sensing Of Sediment Characteristics By Optimized Echo-Envelope Matching, Daniel D. Sternlicht, Christian De Moustier

Center for Coastal and Ocean Mapping

A sediment geoacoustic parameter estimation technique is described which compares bottom returns, measured by a calibrated monostatic sonar oriented within 15° of vertical and having a 10°–21° beamwidth, with an echo envelope model based on high-frequency (10–100 kHz) incoherent backscattertheory and sediment properties such as: mean grain size, strength, and exponent of the power law characterizing the interface roughness energy density spectrum, and volume scattering coefficient. An average echo envelope matching procedure iterates on the reflection coefficient to match the peak echo amplitude and separate coarse from fine-grain sediments, followed by a global optimization using a combination of simulated annealing …


Hypsometry, Volume And Physiography Of The Arctic Ocean And Their Paleoceanographic Implications, Martin Jakobsson, Ron Macnab, Arthur Grantz, Yngue Kristoffersen Nov 2003

Hypsometry, Volume And Physiography Of The Arctic Ocean And Their Paleoceanographic Implications, Martin Jakobsson, Ron Macnab, Arthur Grantz, Yngue Kristoffersen

Center for Coastal and Ocean Mapping

Recent analyses of the International Bathymetric Chart of the Arctic Ocean (IBCAO) grid model include: Hypsometry (the distribution of surface area at various depths); ocean volume distribution; and physiographic provinces [Jakobsson 2002; Jakobsson et al., in press]. The present paper summarizes the main results from these recent studies and expands on the paleoceanographic implications for the Arctic Ocean, which in this work is defined as the broad continental shelves of the Barents, Kara, Laptev, East Siberian and Chukchi Seas, the White Sea and the narrow continental shelves of the Beaufort Sea, the Arctic continental margins off the Canadian Arctic Archipelago …


Strong Mid-Depth Currents And A Deep Cyclonic Gyre In The Gulf Of Mexico, Wilton Sturges, Eric Chassignet, Tal Ezer Nov 2003

Strong Mid-Depth Currents And A Deep Cyclonic Gyre In The Gulf Of Mexico, Wilton Sturges, Eric Chassignet, Tal Ezer

CCPO Publications

The main purpose of this work was to explore the possibility that the deep flow (~2000m) around the edges of the Gulf circulates in a cyclonic, or counter-clockwise direction. The existence of such flow was proposed on theoretical grounds but had not been previously documented. Our results are quite clear that such flow is reliably observed.


Water Quality Monitoring Of Moore's Creek Above Lincoln Lake, M. A. Nelson, L. W. Cash, G. K. Trost Nov 2003

Water Quality Monitoring Of Moore's Creek Above Lincoln Lake, M. A. Nelson, L. W. Cash, G. K. Trost

Technical Reports

No abstract provided.


Water Quality Sampling, Analysis And Annual Load Determinations For Tss, Nitrogen And Phosphorus At The Wyman Road Bridge On The White River, Marc Nelson, Wade Cash Nov 2003

Water Quality Sampling, Analysis And Annual Load Determinations For Tss, Nitrogen And Phosphorus At The Wyman Road Bridge On The White River, Marc Nelson, Wade Cash

Technical Reports

A water quality sampling station was installed at the Wyman Road Bridge just below the confluence of the three main forks of the Upper White River in January 2000. This station is coordinated with the USGS gaging station at the same location. This station was instrumented to collect samples at sufficient intervals across the hydrograph to accurately estimate the flux of total suspended solids, nitrogen and phosphorus into the upper end of Beaver Lake from the Upper White River.


2002 Pollutant Loads Kings River Near Berryville, Arkansas, Marc Nelson, Wade Cash Nov 2003

2002 Pollutant Loads Kings River Near Berryville, Arkansas, Marc Nelson, Wade Cash

Technical Reports

An automatic sampler and a USGS gauging station were established in 1998 and water quality sampling was begun in 1999 on the Kings River near Berryville, Arkansas. Continuous stage and discharge measurements and frequent water quality sampling have been used to determine pollutant concentrations and loads in the river. This report presents the results from the sampling and analysis for January 1, 2002 to December 31, 2002.


Water Quality Sampling, Analysis And Annual Load Determinations For Tss, Nitrogen And Phosphorus At The Washington County Road 195 Bridge On The West Fork Of The White River, Marc Nelson, Wade Cash Nov 2003

Water Quality Sampling, Analysis And Annual Load Determinations For Tss, Nitrogen And Phosphorus At The Washington County Road 195 Bridge On The West Fork Of The White River, Marc Nelson, Wade Cash

Technical Reports

A water quality sampling station was installed at the Washington County Road 195 Bridge on the West Fork of the White River just above the confluence of the three main forks of the Upper White River in December 2001. The Quality Assurance Project Plan (QAPP) was approved by EPA Region Six on March 2002 and sampling was begun at that time. This station is coordinated with a USGS gauging station at the same location. This station was instrumented to collect samples at sufficient intervals across the hydrograph to accurately estimate the flux of total suspended solids, nitrogen and phosphorus into …


Water Quality Sampling, Analysis And Annual Load Determinations For Tss, Nitrogen And Phosphorus At The Washington County Road 76 Bridge On Ballard Creek, Marc A. Nelson, Ron Redman, L. Wade Cash, G. Keith Trost Nov 2003

Water Quality Sampling, Analysis And Annual Load Determinations For Tss, Nitrogen And Phosphorus At The Washington County Road 76 Bridge On Ballard Creek, Marc A. Nelson, Ron Redman, L. Wade Cash, G. Keith Trost

Technical Reports

The Illinois River Basin has experienced water quality impairment from non-point source pollution for many years. This fact was well documented in the State of Arkansas' Water Quality Assessment report, the Soil Conservation Service River Basin Study, and several University of Arkansas, Fayetteville studies. Thirty-seven sub-watersheds have been identified by the SCS in the Arkansas portion of the Illinois River basin. In the Arkansas portion of the Basin, the Illinois River, Evansville Creek, Baron Fork, Cincinnati Creek, Muddy Fork, Moores Creek, Clear Creek, Osage Creek and Flint Creek were all classified as not supporting their designated use as primary contact …


Precipitation Monitoring At Yucca Mountain From 10/01/2000 Through 06/30/2003, Amanda Brandt, Klaus J. Stetzenbach, Amy J. Smiecinski Nov 2003

Precipitation Monitoring At Yucca Mountain From 10/01/2000 Through 06/30/2003, Amanda Brandt, Klaus J. Stetzenbach, Amy J. Smiecinski

Publications (YM)

This report presents precipitation data collected using tipping bucket rain gauges in the vicinity of Yucca Mountain from October 1, 2000 to June 30, 2003. Operation of the tipping bucket precipitation monitoring network was assumed by the Harry Reid Center for Environmental Studies at University of Nevada, Las Vegas in March 2001. Previously, it had been operated by the U.S. Geological Survey. The precipitation monitoring network consists of 17 tipping bucket gauges at various locations in the vicinity of Yucca Mountain. During the 2001 water year, rainfall averaged 6.16 inches. The following 2002 water year was much drier averaging 1.11 …


Time Dependent Seafloor Acoustic Backscatter (10-100khz), Daniel D. Sternlicht, Christian De Moustier Nov 2003

Time Dependent Seafloor Acoustic Backscatter (10-100khz), Daniel D. Sternlicht, Christian De Moustier

Center for Coastal and Ocean Mapping

A time-dependent model of the acoustic intensity backscattered by the seafloor is described and compared with data from a calibrated, vertically oriented, echo-sounder operating at 33 and 93 kHz. The model incorporates the characteristics of the echo-sounder and transmitted pulse, and the water column spreading and absorption losses. Scattering from the water–sediment interface is predicted using Helmholtz–Kirchhoff theory, parametrized by the mean grain size, the coherent reflection coefficient, and the strength and exponent of a power-law roughness spectrum. The composite roughness approach of Jackson et al. [J. Acoust. Soc. Am. 79, 1410–1422 (1986)], modified for the finite duration of …


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 Oct 2003

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 …