Sample records for astrophyllite bay complex
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Incident wave run-up into narrow sloping bays and estuaries
NASA Astrophysics Data System (ADS)
Sinan Özeren, M.; Postacioglu, Nazmi; Canlı, Umut
2015-04-01
The problem is investigated using Carrier Greenspan hodograph transformations.We perform a quasi-one-dimensional solution well into the bay, far enough of the mouth of the bay. The linearized boundary conditions at the mouth of the bay lead to an integral equation for 2-D geometry. A semi analytical optimization method has been developed to solve this integral equation. When the wavelength of the incident wave is much larger than the width of the bay, the conformalmapping of the bay and the semi infinite sea onto upper complex plane provides a solution of the integral equation in closed form. Particular emphasis is placed on the case where the frequency of the incident waves matches the real-part of the natural frequency of the oscillation of the bay. These natural frequencies are complex because of the radiation conditions imposed at the mouth of the bay. It is found that the complex part of these natural frequencies decreases with decreasing width of the bay. Thus the trapping of the waves in narrower bays leads to a strong resonance phenomenon when the frequency of the incident wave is equal to the real part of the natural frequency.
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-04-10
...) 792-5828. Mail: U.S. Fish and Wildlife Service, San Francisco Bay NWR Complex, 1 Marshlands Road... the San Francisco Bay National Wildlife Refuge Complex, 1 Marshlands Road, Fremont, CA 94555 (510) 792... and environmental education. We announce our decision and the availability of the FONSI for the final...
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Structure, age and origin of the bay-mouth shoal deposits, Chesapeake Bay, Virginia
Colman, Steven M.; Berquist, C.R.; Hobbs, C. H.
1988-01-01
The mouth of Chesapeake Bay contains a distinctive shoal complex and related deposits that result from the complex interaction of three different processes: (1) progradation of a barrier spit at the southern end of the Delmarva Peninsula, (2) strong, reversing tidal currents that transport and rework sediment brought to the bay mouth from the north, and (3) landward (bayward) net non-tidal circulation and sediment transport. Together, these processes play a major role in changing the configuration of the estuary and filling it with sediment. The deposits at the mouth of the bay hold keys both to the evolution of the bay during the Holocene transgression and to the history of previous generations of the bay. The deposit associated with the shoals at the mouth of the bay, the bay-mouth sand, is a distinct stratigraphic unit composed mostly of uniform, gray, fine sand. The position and internal structure of the unit shows that it is related to near-present sea level, and thus is less than a few thousand years old. The processes affecting the upper surface of the deposit and the patterns of erosion and deposition at this surface are complex, but the geometry and structure of the deposit indicate that it is a coherent unit that is prograding bayward and tending to fill the estuary. The source of the bay-mouth sand is primarily outside the bay in the nearshore zone of the Delmarva Peninsula and on the inner continental shelf. The internal structure of the deposit, its surface morphology, its heavy-mineral composition, bottom-current studies, comparative bathymetry, and sediment budgets all suggest that sand is brought to the bay mouth by southerly longshore drift along the Delmarva Peninsula and then swept into the bay. In addition to building the southward- and bayward-prograding bay-mouth sand, these processes result in sand deposition tens of kilometers into the bay. ?? 1988.
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1. GENERAL VIEW OF COMPLEX, SHOWING FACTORY BUILDING IN LEFT ...
1. GENERAL VIEW OF COMPLEX, SHOWING FACTORY BUILDING IN LEFT FOREGROUND, GRINDING PLATFORM AT REAR OF FACTORY, AND STABLE AREA AND OVERSEER'S HOUSE TO RIGHT - Caneel Bay Plantation, General Views, Cruz Bay, St. John, VI
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ERIC Educational Resources Information Center
Helrich, Jane
Project MER (Marine Ecology Research) is aimed at improving environmental education in the San Francisco Bay Area schools. This document is the second of a series of guides designed to help students and teachers gather data concerning the San Francisco Bay-Delta-Estuary Complex and to organize these data to make a contribution to the literature of…
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Kampf, Anthony R.; Rossman, George R.; Steele, Ian M.
2010-03-30
Devitoite, [Ba{sub 6}(PO{sub 4}){sub 2}(CO{sub 3})] [Fe{sup 2+}{sub 7}Fe{sup 3+}{sub 2}(Si{sub 4}O{sup 12}){sub 2}O{sub 2}(OH){sub 4}], is a new mineral species from the Esquire No.8 claim along Big Creek in eastern Fresno County, California, U.S.A. It is also found at the nearby Esquire No.7 claim and at Trumbull Peak in Mariposa County. The mineral is named for Alfred (Fred) DeVito (1937-2004). Devitoite crystallized very late in a sequence of minerals resulting from fluids interacting with a quartz-sanbornite vein along its margin with the country rock. The mineral occurs in subparallel intergrowths of very thin brown blades, flattened on {l_brace}001{r_brace} andmore » elongate and striated parallel to [100]. The mineral has a cream to pale brown streak, a silky luster, a Mohs hardness of approximately 4, and two cleavages: {l_brace}001{r_brace} perfect and {l_brace}010{r_brace} good.« less
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San Francisco Bay, California as seen from STS-59
1994-04-14
STS059-213-009 (9-20 April 1994) --- San Francisco Bay. Orient with the sea up. The delta of the combined Sacramento and San Joaquin Rivers occupies the foreground, San Francisco Bay the middle distance, and the Pacific Ocean the rest. Variations in water color caused both by sediment load and by wind streaking strike the eye. Man-made features dominate this scene. The Lafayette/Concord complex is left of the bay head, Vallejo is to the right, the Berkeley/Oakland complex rims the shoreline of the main bay, and San Francisco fills the peninsula beyond. Salt-evaporation ponds contain differently-colored algae depending on salinity. The low altitude (less than 120 nautical miles) and unusually-clear air combine to provide unusually-strong green colors in this Spring scene. Hasselblad camera.
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San Francisco Bay, California as seen from STS-59
NASA Technical Reports Server (NTRS)
1994-01-01
San Francisco Bay as seen from STS-59. View is oriented with the sea up. The delta of the combined Sacramento and San Joaquin Rivers occupies the foreground with San Francisco Bay in the middle distance, then the Pacific Ocean. Variations in water color caused both by sediment load and by wind streaking strike the eye. Man-made features dominate this scene. The Lafayette/Concord complex is left of the bay head, Vallejo is to the right, the Berkeley/Oakland complex rims the shoreline of the main bay, and San Francisco fills the peninsula beyond. Salt-evaporation ponds contain differently-colored algae depending on salinity. The low altitude (less than 120 nautical miles) and unusually-clear air combine to provide unusually-strong green colors in this Spring scene.
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MASS BALANCE MODELLING OF PCBS IN THE FOX RIVER/GREEN BAY COMPLEX
The USEPA Office of Research and Development developed and applies a multimedia, mass balance modeling approach to the Fox River/Green Bay complex to aid managers with remedial decision-making. The suite of models were applied to PCBs due to the long history of contamination and ...
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ECOSYSTEM MODELING IN COBSCOOK BAY, MAINE:A SUMMARY, PERSPECTIVE, AND LOOK FORWARD
In the mid-1990s, an interdisciplinary, multi-institutional team of scientists was assembled to address basic issues concerning biological productivity and the unique co-occurrence of many unusual ecological features in Cobscook Bay, Maine. Cobscook Bay is a geologically complex,...
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NASA Astrophysics Data System (ADS)
Skrabal, Stephen A.; Donat, John R.; Burdige, David J.
2000-06-01
The distributions and seasonal variability of total dissolved Cu (TDCu) and Cu-complexing ligands in sediment pore waters have been investigated at two contrasting sites in the Chesapeake Bay. Two ligand classes, which differ on the basis of the conditional stability constants ( K'cond) of their Cu complexes, were detected at all depths at both sites. At the sulfidic, muddy, mid-Bay Sta. M, concentrations and values of log K'cond ranged from 390-12,500 nM and ≥7.2->8.9, respectively, for the stronger ligand class ( L1 S) and 75-6,420 nM and 6.2-7.9 for the weaker ligand class ( L2 S). At the bioturbated, sandy Sta. S in the lower Bay, respective concentrations and values of log K'cond ranged from 135-807 nM and ≥7.6-≥10.2 for L1 S and 40-1,410 nM and 6.6-9.2 for L2 S. For comparison, one pore water profile from a slope station off of the Chesapeake Bay also showed the presence of two ligand classes, with respective concentrations and values of log K'cond of 140-270 nM and 8->11 for L1 S and 30-180 nM and 7-10 for L2 S. These ligands are in large excess relative to ambient TDCu concentrations (<0.1-24.3 nM), thereby maintaining very low inorganic Cu concentrations (typically <0.1 to <100 pM) and a high degree of organic complexation (87.2->99.9%) of Cu in Bay and slope sediment pore waters. Thus, virtually all TDCu fluxing from these sediments is complexed during sediment-water exchange. A relatively small fraction of the TDCu is exchanged as inorganic species, which are widely regarded as the most bioavailable form of Cu. Higher ligand concentrations at Sta. M suggest that sulfide or organic ligands containing reduced S contribute to the pool of complexing ligands; however, the exact nature and sources of the ligands in Bay pore waters are not known. The progressive increase in conditional stability constants of the CuL 2 S complexes from the mid-Bay to the slope sediments may reflect differences in biological or chemical processes at each site, as well as differences in the type of Cu-complexing organic matter. Total ligand concentrations ( L1 S + L2 S) are 15 to >100 times higher in the upper intervals of the pore waters relative to ligand concentrations in the bottom waters of the Chesapeake Bay (30-60 nM), consistent with previous observations of fluxes of these ligands from the sediments to overlying waters. These results suggest that sediments are potentially significant sources of Cu-complexing ligands to the overlying waters of the Chesapeake Bay, and perhaps, other shallow water estuarine and coastal environments. Copper-complexing ligands released from sediment pore waters may play an important role in influencing Cu speciation in overlying waters.
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Modeling Diel Oxygen Dynamics and Ecosystem Metabolism in Weeks Bay, Alabama.
Weeks Bay is a shallow eutrophic estuary that exhibits frequent summertime diel-cycling hypoxia and periods of dissolved oxygen (DO) oversaturation during the day. Diel DO dynamics in shallow estuaries like Weeks Bay are complex, and may be influenced by wind forcing, vertical an...
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Ortiz, D I; Wozniak, A; Tolson, M W; Turner, P E
2005-01-01
Carolina bays, a type of geomorphic feature, may be important in the ecology of mosquito vectors in South Carolina. Their hydrology varies from wetland habitats with marked flooding/drying regimes to permanently flooded spring-fed lakes. Moreover, they possess characteristics that contribute to the support of a particularly abundant and diverse invertebrate fauna. Although it has been estimated that 2,700+ bays exist in South Carolina, approximately 97% have been altered; < or = 200 bays remain intact, and only 36 are protected by state-funded conservation projects. We conducted a study in two distinct Carolina bay habitats, Savage Bay Heritage Preserve (SBHP) and Woods Bay State Park (WBSP), from June 1997 to July 1998 to determine mosquito temporal distribution, species composition, and the occurrence of arbovirus activity. The largest mosquito collection was obtained at WBSP (n = 31,172) representing 25 species followed by SBHP (n = 3,940) with 24 species. Anopheles crucians complex were the most common species encountered in both bays. Two virus isolates were obtained from SBHP in 1997: Keystone (KEY) virus from Ochlerotatus atlanticus-tormentor and Cache Valley (CV) virus from Oc. canadensis canadensis. Twenty-nine (29) arbovirus-positive pools were obtained from WBSP: 28 in 1997 and one in 1998. KEY virus was isolated from three pools of Oc. atlanticus-tormentor and Tensaw (TEN) virus was isolated from two pools of An. crucians complex; 10 isolates could not be identified with the sera available. Additionally, 14 pools of An. crucians complex tested positive for Eastern equine encephalitis (EEE) virus antigen. These represent the first record of KEY and CV viruses in South Carolina. Our data indicate the presence of high mosquito density and diversity in both Carolina bay habitats, which may be influenced, in part, by seasonal changes in their hydroperiods. The study of mosquito and arbovirus ecology in Carolina Bay habitats could provide more information on the transmission dynamics of arboviruses and its impact on human and animal arboviral disease occurrence in South Carolina.
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Decision Making/The Chesapeake Bay. An Interdisciplinary Environmental Education Curriculum Unit.
ERIC Educational Resources Information Center
Maryland Univ., College Park. Science Teaching Center.
This multidisciplinary, self-contained curriculum unit focuses on the management of the Chesapeake Bay, a threatened and complex environmental system. Major unit goals include identifying and analyzing conflicting interests, issues, and public policies concerning the Bay, and determining their effects on people and the environment. The unit…
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Shark Bay, Australia as seen from STS-67 Endeavour
NASA Technical Reports Server (NTRS)
1995-01-01
An oblique view of the Shark Bay complex from the east. Hamelin Pool at the center of the photo and Shark Bay proper are separated from Freycinet Estuary and Denham Sound by the Peron Peninsula. These, in turn, are separated from the Indian Ocean by Edel Land Peninsula and Dirk Hartog Island. This arid western coast of western Australia is very sparsely populated, but a few roads can be seen. A complex set of lime-sediment shoals and tidal passes forms the Disappointment Reach shallows. Some red, land-derived mud does make its way into the inter tidal zone along the coast north of the reach. The clouds of light-colored water in Shark Bay and Denham Sound may either be lime sediment, perhaps percipitated from sea water (whitings), or a plankton bloom.
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View of garage interior from northern bay looking south. ...
View of garage interior from northern bay looking south. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA
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Christopher D. Barton; Danielle M. Andrews; Randall K. Kolka
2008-01-01
Carolina bays are shallow depression wetlands found in the southeastern United States that have been severely altered by human activity. The need to restore these complex and diverse systems is well established, but our limited understanding of wetland hydrologic processes in these systems hinders our ability to assess the effectiveness of bay restoration efforts....
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Numerical Simulation of Regional Circulation in the Monterey Bay Region
NASA Technical Reports Server (NTRS)
Tseng, Y. H.; Dietrich, D. E.; Ferziger, J. H.
2003-01-01
The objective of this study is to produce a high-resolution numerical model of Mon- terey Bay area in which the dynamics are determined by the complex geometry of the coastline, steep bathymetry, and the in uence of the water masses that constitute the CCS. Our goal is to simulate the regional-scale ocean response with realistic dynamics (annual cycle), forcing, and domain. In particular, we focus on non-hydrostatic e ects (by comparing the results of hydrostatic and non-hydrostatic models) and the role of complex geometry, i.e. the bay and submarine canyon, on the nearshore circulation. To the best of our knowledge, the current study is the rst to simulate the regional circulation in the vicinity of Monterey Bay using a non-hydrostatic model. Section 2 introduces the high resolution Monterey Bay area regional model (MBARM). Section 3 provides the results and veri cation with mooring and satellite data. Section 4 compares the results of hydrostatic and non-hydrostatic models.
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Facility Layout Problems Using Bays: A Survey
NASA Astrophysics Data System (ADS)
Davoudpour, Hamid; Jaafari, Amir Ardestani; Farahani, Leila Najafabadi
2010-06-01
Layout design is one of the most important activities done by industrial Engineers. Most of these problems have NP hard Complexity. In a basic layout design, each cell is represented by a rectilinear, but not necessarily convex polygon. The set of fully packed adjacent polygons is known as a block layout (Asef-Vaziri and Laporte 2007). Block layout is divided by slicing tree and bay layout. In bay layout, departments are located in vertical columns or horizontal rows, bays. Bay layout is used in real worlds especially in concepts such as semiconductor and aisles. There are several reviews in facility layout; however none of them focus on bay layout. The literature analysis given here is not limited to specific considerations about bay layout design. We present a state of art review for bay layout considering some issues such as the used objectives, the techniques of solving and the integration methods in bay.
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View of front of garage bays 57, facing northeast. ...
View of front of garage bays 5-7, facing northeast. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA
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View of front of garage, bays 37, facing south ...
View of front of garage, bays 3-7, facing south - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA
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View of front of garage, bays 14, facing northeast ...
View of front of garage, bays 1-4, facing northeast - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA
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View of front and side of garage, bay 7, facing ...
View of front and side of garage, bay 7, facing east. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA
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Dissolved sulfides in the oxic water column of San Francisco Bay, California
Kuwabara, J.S.; Luther, G.W.
1993-01-01
Trace contaminants enter major estuaries such as San Francisco Bay from a variety of point and nonpoint sources and may then be repartitioned between solid and aqueous phases or altered in chemical speciation. Chemical speciation affects the bioavailability of metals as well as organic ligands to planktonic and benthic organisms, and the partitioning of these solutes between phases. Our previous, work in south San Francisco Bay indicated that sulfide complexation with metals may be of particular importance because of the thermodynamic stability of these complexes. Although the water column of the bay is consistently well-oxygenated and typically unstratified with respect to dissolved oxygen, the kinetics of sulfide oxidation could exert at least transient controls on metal speciation. Our initial data on dissolved sulfides in the main channel of both the northern and southern components of the bay consistently indicate submicromolar concenrations (from <1 nM to 162 nM), as one would expect in an oxidizing environment. However, chemical speciation calculations over the range of observed sulfide concentrations indicate that these trace concentrations in the bay water column can markedly affect chemical speciation of ecologically significant trace metals such as cadmium, copper, and zinc.
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View of back of garage, windows of bays 13, facing ...
View of back of garage, windows of bays 1-3, facing southwest. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA
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View of front and side of garage, bays 67, facing ...
View of front and side of garage, bays 6-7, facing northeast. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA
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7. INTERIOR VIEW, SHOWING PROPELLER TEST STAND AND BOMB BAYS. ...
7. INTERIOR VIEW, SHOWING PROPELLER TEST STAND AND BOMB BAYS. - Wright-Patterson Air Force Base, Area B, Building No. 20A, Propeller Test Complex, Seventh Street, from E to G Streets, Dayton, Montgomery County, OH
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5. INTERIOR VIEW, SHOWING PROPELLER TEST STAND AND BOMB BAYS. ...
5. INTERIOR VIEW, SHOWING PROPELLER TEST STAND AND BOMB BAYS. - Wright-Patterson Air Force Base, Area B, Building No. 20A, Propeller Test Complex, Seventh Street, from E to G Streets, Dayton, Montgomery County, OH
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EAST ELEVATION OF HIGH BAY ADDITION OF FUEL STORAGE BUILDING ...
EAST ELEVATION OF HIGH BAY ADDITION OF FUEL STORAGE BUILDING (CPP-603). INL DRAWING NUMBER 200-0603-00-706-051286. - Idaho National Engineering Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex, Scoville, Butte County, ID
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AmeriFlux US-Srr Suisun marsh - Rush Ranch
Bergamaschi, Brian [USGS; Windham-Myers, Lisamarie [USGS
2018-01-01
This is the AmeriFlux version of the carbon flux data for the site US-Srr Suisun marsh - Rush Ranch. Site Description - This site is a 4.57 km2 brackish tidal marsh located in the San Francisco Bay National Estuarine Research Reserve (SFBNERR, http://www.nerrs.noaa.gov/reserves/san-francisco-bay.html) in Suisun Bay, CA, USA. Suisun Bay is the most extensive contiguous brackish marsh complex in California. This site is classified as a high marsh, which according to the National Wetland Inventory, is representative of over 58% of estuarine wetlands.
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5. View bay door and single man door on north ...
5. View bay door and single man door on north elevation of power plant, looking south - Naval Air Station Fallon, Power Plant, 800 Complex, off Carson Road near intersection of Pasture & Berney Roads, Fallon, Churchill County, NV
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DOE Office of Scientific and Technical Information (OSTI.GOV)
None
AvalonBay Communities, which is a large multifamily developer, was developing a three-building complex in Elmsford, New York. The buildings were planned to be certified to the ENERGY STAR® Homes Version 3 program. This plan led to AvalonBay partnering with the Advanced Residential Integrated Solutions (ARIES) collaborative, which is a U.S. Department of Energy Building America team. ARIES worked with AvalonBay to redesign the project to comply with Zero Energy Ready Home (ZERH) criteria.
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NASA Astrophysics Data System (ADS)
Barros Grace, Virgínia; Mas-Pla, Josep; Oliveira Novais, Therezinha; Sacchi, Elisa; Zuppi, Gian Maria
2008-03-01
The hydrologic complex of Babitonga Bay (Brazil) forms a vast environmental complex where agriculture, shellfish farming, and industries coexist with a unique natural area of Atlantic rain forest and mangrove systems. The origin of different continental hydrological components, the environmental transition between saline and freshwaters, and the influence of the seasonality on Babitonga Bay waters are evaluated using isotopes and chemistry. End-member mixing analysis is used to explore hydrological processes in the bay. We show that a mixing of waters from different origins takes place in the bay modifying its chemical characteristics. Furthermore, biogeochemical processes related to well-developed mangrove systems are responsible for an efficient bromide uptake, which limit its use as a tracer as commonly used in non-biologically active environments. Seasonal behaviours are also distinguished from our datasets. The rainy season (April) provides a homogenization of the hydrological processes that is not seen after the dry season (October), when larger spatial differences appear and when the effects of biological processes on the bay hydrochemistry are more dynamic, or can be better recognized. Moreover, Cl/Br and stable isotopes of water molecule allow a neat definition of the hydrological and biogeochemical processes that control chemical composition in coastal and transition areas.
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Distribution of macroalgae and seaweed in the Azov Sea, Kerch Strait, and Taman Bay
NASA Astrophysics Data System (ADS)
Stepanian, O. V.
2009-06-01
The analysis of the macroalgae distribution along the salinity gradient in the Azov Sea, the Kerch strait, and Taman Bay during the summer allowed finding two macroalgae complexes. The first complex (brackish) is formed by algae belonging to the Enteromorpha, Cladophora, Rhizoclonium, and Chaetomorpha genera in the Taganrog Gulf. The second complex (marine) with dominating algae belonging to the Enteromorpha, Chaetomorpha, Ceramium, and Polysiphonia inhabits the littoral part of the Azov Sea itself, the Kerch Strait, and Taman Bay. The saprobe analysis of the flora showed that the majority of macroalgae species inhabiting the Azov Sea are represented by meso- and polysaprobes and a small number of oligosaprobe species inhabit the Kerch Strait. The biggest species diversity of macroalgae was noted in the southwestern part of the sea; the value of Shannon’s index was 0.65 in the Taganrog Gulf, 1.04 in the Azov Sea, 1.38 in Taman Bay. The leading role in the littoral communities of Taganrog Gulf belongs to aquatic flowering plants with Potamogeton perfoliatus being dominant; as the salinity increases, the share of such species as P. pectinatus, Zostera marina, Z. noltii, Ruppia maritime, and Zannichellia major starts to increase.
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Rare Mineralogy in Alkaline Ultramafic Rocks, Western Kentucky Fluorspar District
NASA Astrophysics Data System (ADS)
Anderson, W.
2017-12-01
The alkaline ultramafic intrusive dike complex in the Western Kentucky Fluorspar District contains unusual mineralogy that was derived from mantle magma sources. Lamprophyre and peridotite petrologic types occur in the district where altered fractionated peridotites are enriched in Rare Earth Elements (REE) and some lamprophyre facies are depleted in incompatible elements. Unusual minerals in dikes, determined by petrography and X-ray diffraction, include schorlomite and andradite titanium garnets, astrophyllite, spodumene, niobium rutile, wüstite, fluoro-tetraferriphlogopite, villiaumite, molybdenite, and fluocerite, a REE-bearing fluoride fluorescent mineral. Mixing of MVT sphalerite ore fluids accompanies a mid-stage igneous alteration and intrusion event consistent with paragenetic studies. The presence of lithium in the spodumene and fluoro-tetraferriphlogopite suggests a lithium phase in the mineral fluids, and the presence of enriched REE in dikes and fluorite mineralization suggest a metasomatic event. Several of these rare minerals have never been described in the fluorspar district, and their occurrence suggests deep mantle metasomatism. Several REE-bearing fluoride minerals occur in the dikes and in other worldwide occurrences, they are usually associated with nepheline syenite and carbonatite differentiates. There is an early and late stage fluoride mineralization, which accompanied dike intrusion and was also analyzed for REE content. One fluorite group is enriched in LREE and another in MREE, which suggests a bimodal or periodic fluorite emplacement. Whole-rock elemental analysis was chondrite normalized and indicates that some of the dikes are slightly enriched in light REE and show a classic fractionation enrichment. Variations in major-element content; high titanium, niobium, and zirconium values; and high La/Yb, Zr/Y, Zr/Hf, and Nb/Ta ratios suggest metasomatized lithospheric-asthenospheric mantle-sourced intrusions. The high La/Yb ratios in some dikes in the titanium garnet facies suggest a magma melt trend toward the carbonation phase of a fractionated peridotite parent magma.
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The Influence of Baker Bay and Sand Island on Circulations in the Mouth of the Columbia River
2014-06-01
the presence of Baker Bay, a shallow sub -embayment, adds further complexity. Drifter velocities were greatest during maximum ebb flows and were...Drifters occasionally entered Baker Bay via Baker Inlet during flood flows , especially in conjunction with strong southwesterly winds. During ebb flows ...occurred in the vicinity of the pile dikes, including reversed (upriver) flow between the pile dikes during maximum ebb . Understanding unique flow
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Lessons from monitoring water quality in San Francisco Bay
Cloern, J.E.; Schraga, T.S.; Lopez, C.B.; Labiosa, R.
2003-01-01
Bay Area residents feel a sense of responsibility to protect San Francisco Bay and keep it healthy. Some even dream about the recovery of fish stocks so they can sustain commercial fishing once again inside the Bay. How is our Bay doing? Is it highly polluted or pretty clean? How does its health compare with other estuaries in the United States? Are things getting better or worse? Does costly wastewater treatment have benefits? What are the biggest threats to the Bay and how can we reduce or eliminate those threats? How will the Bay change in the future? These questions can only be answered with investments in study and monitoring, and they are the driving force behind the Regional Monitoring Program (RMP). We describe here some selected results from water quality surveillance conducted by the U.S. Geological Survey (USGS) as one component of the RMP. We present results as lessons about how the Bay works as a complex dynamic system, and we show how these lessons are relevant to the broad RMP objectives supporting Bay protection and management.
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Optimal pollution mitigation in Monterey Bay based on coastal radar data and nonlinear dynamics.
Coulliette, Chad; Lekien, Francois; Paduan, Jeffrey D; Haller, George; Marsden, Jerrold E
2007-09-15
High-frequency (HF) radar technology produces detailed velocity maps near the surface of estuaries and bays. The use of velocity data in environmental prediction, nonetheless, remains unexplored. In this paper, we uncover a striking flow structure in coastal radar observations of Monterey Bay, along the California coastline. This complex structure governs the spread of organic contaminants, such as agricultural runoff which is a typical source of pollution in the bay. We show that a HF radar-based pollution release scheme using this flow structure reduces the impact of pollution on the coastal environment in the bay. We predict the motion of the Lagrangian flow structures from finite-time Lyapunov exponents of the coastal HF velocity data. From this prediction, we obtain optimal release times, at which pollution leaves the bay most efficiently.
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Conomos, T.J.; McCulloch, D.S.; Peterson, D.H.; Carlson, P.R.
1972-01-01
The San Francisco Bay system is a complex estuary in which there is an interplay between natural chemical and physical processes, and changes resulting from the works of man. The bay is used for recreation, water-borne commerce, fishing, domestic and industrial waste disposal, and esthetic pleasure. Because some of these uses are competitive, it is desirable to adequately predict the impact of man's activities on this natural system. The reliability of such predictions will be strengthened by long-term observations directed toward understanding the natural processes occurring in the bay. This study is a compilation of one aspect of the U.S. Geological Survey's continuing investigations of the San Francisco Bay system.
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Brew, D.A.; Himmelberg, G.R.; Loney, R.A.; Ford, A.B.
1992-01-01
The Cordilleran orogen in south-eastern Alaska includes 14 distinct metamorphic belts that make up three major metamorphic complexes, from east to west: the Coast plutonic-metamorphic complex; the Glacier Bay-Chichagof plutonic-metamorphic complex; and the Chugach plutonic-metamorphic complex. Each of these complexes is related to a major subduction event. The metamorphic history of the Coast complex is lengthy and is related to the Late Cretaceous collision of the Alexander and Wrangellia terranes and the Gravina overlap assemblage to the west against the Stikine terrane to the east. The metamorphic history of the Glacier Bay-Chichagof complex is relatively simple and is related to the roots of a Late Jurassic to late Early Cretaceous island arc. The metamorphic history of the Chugach is complicated and developed during and after the Late Cretaceous collision of the Chugach terrane with the Wrangellia and Alexander terranes. -from Authors
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ERIC Educational Resources Information Center
Sikora, Bob
Project MER (Marine Ecology Research) is aimed at improving environmental education in the San Francisco Bay Area schools. As part of meeting this goal, it is hoped that students and teachers can see the results of their efforts being put to practical use. This guide is the sixth of a series produced to help students and teachers gather data…
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50. DETAIL OF TYPICAL PANELS IN ANALOG RECORD BAY. LEFT ...
50. DETAIL OF TYPICAL PANELS IN ANALOG RECORD BAY. LEFT PANEL CONTAINS OSCILLOGRAPH AND CONTROLS. RIGHT PANEL CONTAINS CATHODE RAY TUBE AND INK-TYPE CHART RECORDER. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA
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VIEW OF HB1 (VAB HIGH BAY) WITH MOBILE LAUNCHER PLATFORM ...
VIEW OF HB-1 (VAB HIGH BAY) WITH MOBILE LAUNCHER PLATFORM (VEHICLE ACCESS PLATFORMS ARE VISIBLE IN THE CENTER), FACING WEST - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL
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2012-09-13
CAPE CANAVERAL, Fla. – In Bay 2 of the Orbiter Processing Facility at NASA's Kennedy Space Center in Florida, the space shuttle Atlantis' payload bay is being configured for display at the Kennedy Space Center Visitor Complex. Plans call for the orbiter to be transferred to the Visitor Complex in November. The work is part of Transition and Retirement of the remaining space shuttles, Atlantis and Endeavour. Atlantis is being prepared for public display at Kennedy's Visitor Complex. Over the course of its 26-year career, Atlantis spent 293 days in space during 33 missions. For more information, visit http://www.nasa.gov/transition Photo credit: NASA/Jim Grossmann
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NASA Astrophysics Data System (ADS)
Schaefer, R. K.; Nix, M.; Ihde, A. G.; Paxton, L. J.; Weiss, M.; Simpkins, S.; Fountain, G. H.; APl GAIA Team
2011-12-01
In this paper we describe the application of a proven methodology for modeling the complex social and economic interactions of a system under stress to the regional issues that are tied to global climate disruption. Under the auspices of the GAIA project (http://gaia.jhuapl.edu), we have investigated simulating the complex interplay between climate, politics, society, industry, and the environment in the Chesapeake Bay Watershed and associated geographic areas of Maryland, Virginia, and Pennsylvania. This Chesapeake Bay simulation draws on interrelated geophysical and climate models to support decision-making analysis about the Bay. In addition to physical models, however, human activity is also incorporated via input and output calculations. For example, policy implications are modeled in relation to business activities surrounding fishing, farming, industry and manufacturing, land development, and tourism. This approach fosters collaboration among subject matter experts to advance a more complete understanding of the regional impacts of climate change. Simulated interactive competition, in which teams of experts are assigned conflicting objectives in a controlled environment, allow for subject exploration which avoids trivial solutions that neglect the possible responses of affected parties. Results include improved planning, the anticipation of areas of conflict or high risk, and the increased likelihood of developing mutually acceptable solutions.
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Underwater Gravity Survey of Northern Monterey Bay.
stations were occupied just above the swash zone. A complete Bouguer anomaly map was drawn and tied in with the previous land surveys and with one...covering the southern half of the bay. The isolines of the complete Bouguer anomaly indicate the relative vertical position of the basement complex Santa
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EAST/WEST TRUCK BAY AREA OF TRANSFER BASIN CORRIDOR OF FUEL ...
EAST/WEST TRUCK BAY AREA OF TRANSFER BASIN CORRIDOR OF FUEL STORAGE BUILDING (CPP-603). PHOTO TAKEN LOOKING NORTHWEST. INL PHOTO NUMBER HD-54-19-1. Mike Crane, Photographer, 8/2005 - Idaho National Engineering Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex, Scoville, Butte County, ID
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Modeling Diel Oxygen Dynamics and Ecosystem Metabolism in a Shallow, Eutrophic Estuary
Weeks Bay is a shallow eutrophic estuary that exhibits frequent summertime diel-cycling hypoxia and periods of dissolved oxygen (DO) oversaturation during the day. Diel DO dynamics in shallow estuaries like Weeks Bay are complex, and may be influenced by wind forcing, vertical an...
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2001-06-20
CAPE CANAVERAL, Fla. – An aerial view of Launch Complex 39 shows the south and west sides of the Vehicle Assembly Building. The curved roadway heading to the VAB leads to high bay 2, the Safe Haven facility constructed in 2000. Beyond it is the Orbiter Processing Facility, bays 1 and 2. The OPF bay 3 is farther still, closer to the VAB. Farther in the background are the waters of the Banana Creek in the Merritt Island National Wildlife Refuge. Photo credit: NASA
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Hoeke, R.; Storlazzi, C.; Ridd, P.
2011-01-01
This paper examines the relationship between offshore wave climate and nearshore waves and currents at Hanalei Bay, Hawaii, an exposed bay fringed with coral reefs. Analysis of both offshore in situ data and numerical hindcasts identify the predominance of two wave conditions: a mode associated with local trade winds and an episodic pattern associated with distant source long-period swells. Analysis of 10 months of in situ data within the bay show that current velocities are up to an order of magnitude greater during long-period swell episodes than during trade wind conditions; overall circulation patterns are also fundamentally different. The current velocities are highly correlated with incident wave heights during the swell episodes, while they are not during the modal trade wind conditions. A phase-averaged wave model was implemented with the dual purpose of evaluating application to bathymetrically complex fringing reefs and to examine the propagation of waves into the nearshore in an effort to better explain the large difference in observed circulation during the two offshore wave conditions. The prediction quality of this model was poorer for the episodic condition than for the lower-energy mode, however, it illustrated how longer-period swells are preferentially refracted into the bay and make available far more nearshore wave energy to drive currents compared to waves during modal conditions. The highly episodic circulation, the nature of which is dependent on complex refraction patterns of episodic, long-period swell has implications for flushing and sediment dynamics for incised fringing reef-lined bays that characterize many high islands at low latitudes around the world.
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Rosenbauer, Robert J.; Foxgrover, Amy C.; Hein, James R.; Swarzenski, Peter W.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.
2013-01-01
A diverse suite of geochemical tracers, including 87Sr/86Sr and 143Nd/144Nd isotope ratios, the rare earth elements (REEs), and select trace elements were used to determine sand-sized sediment provenance and transport pathways within the San Francisco Bay coastal system. This study complements a large interdisciplinary effort (Barnard et al., 2012) that seeks to better understand recent geomorphic change in a highly urbanized and dynamic estuarine-coastal setting. Sand-sized sediment provenance in this geologically complex system is important to estuarine resource managers and was assessed by examining the geographic distribution of this suite of geochemical tracers from the primary sources (fluvial and rock) throughout the bay, adjacent coast, and beaches. Due to their intrinsic geochemical nature, 143Nd/144Nd isotopic ratios provide the most resolved picture of where sediment in this system is likely sourced and how it moves through this estuarine system into the Pacific Ocean. For example, Nd isotopes confirm that the predominant source of sand-sized sediment to Suisun Bay, San Pablo Bay, and Central Bay is the Sierra Nevada Batholith via the Sacramento River, with lesser contributions from the Napa and San Joaquin Rivers. Isotopic ratios also reveal hot-spots of local sediment accumulation, such as the basalt and chert deposits around the Golden Gate Bridge and the high magnetite deposits of Ocean Beach. Sand-sized sediment that exits San Francisco Bay accumulates on the ebb-tidal delta and is in part conveyed southward by long-shore currents. Broadly, the geochemical tracers reveal a complex story of multiple sediment sources, dynamic intra-bay sediment mixing and reworking, and eventual dilution and transport by energetic marine processes. Combined geochemical results provide information on sediment movement into and through San Francisco Bay and further our understanding of how sustained anthropogenic activities which limit sediment inputs to the system (e.g., dike and dam construction) as well as those which directly remove sediments from within the Bay, such as aggregate mining and dredging, can have long-lasting effects
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Padilla Bay: The Estuary Guide. Level 2.
ERIC Educational Resources Information Center
Friesem, Judy; Lynn, Valerie, Ed.
Estuaries are marine systems that serve as nurseries for animals, links in the migratory pathways, and habitat for a complex community of organisms. This curriculum guide intended for use at the middle school level is designed for use with the on-site program developed by the Padilla Bay National Esturine Research Reserve (Washington). The guide…
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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...
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ERIC Educational Resources Information Center
Satake, Eiki; Amato, Philip P.
2008-01-01
This paper presents an alternative version of formulas of conditional probabilities and Bayes' rule that demonstrate how the truth table of elementary mathematical logic applies to the derivations of the conditional probabilities of various complex, compound statements. This new approach is used to calculate the prior and posterior probabilities…
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Bever, Aaron J.; MacWilliams, Michael L.; Herbold, Bruce; Brown, Larry R.; Feyrer, Frederick V.
2016-01-01
Long-term fish sampling data from the San Francisco Estuary were combined with detailed three dimensional hydrodynamic modeling to investigate the relationship between historical fish catch and hydrodynamic complexity. Delta Smelt catch data at 45 stations from the Fall Midwater Trawl (FMWT) survey in the vicinity of Suisun Bay were used to develop a quantitative catch-based station index. This index was used to rank stations based on historical Delta Smelt catch. The correlations between historical Delta Smelt catch and 35 quantitative metrics of environmental complexity were evaluated at each station. Eight metrics of environmental conditions were derived from FMWT data and 27 metrics were derived from model predictions at each FMWT station. To relate the station index to conceptual models of Delta Smelt habitat, the metrics were used to predict the station ranking based on the quantified environmental conditions. Salinity, current speed, and turbidity metrics were used to predict the relative ranking of each station for Delta Smelt catch. Including a measure of the current speed at each station improved predictions of the historical ranking for Delta Smelt catch relative to similar predictions made using only salinity and turbidity. Current speed was also found to be a better predictor of historical Delta Smelt catch than water depth. The quantitative approach developed using the FMWT data was validated using the Delta Smelt catch data from the San Francisco Bay Study. Complexity metrics in Suisun Bay were-evaluated during 2010 and 2011. This analysis indicated that a key to historical Delta Smelt catch is the overlap of low salinity, low maximum velocity, and low Secchi depth regions. This overlap occurred in Suisun Bay during 2011, and may have contributed to higher Delta Smelt abundance in 2011 than in 2010 when the favorable ranges of the metrics did not overlap in Suisun Bay.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Cross, David; Waite, Ian
1988-06-01
The Lower Flathead System Fisheries Study assessed the effects of Kerr Dam operation on the fisheries of the lower Flathead ecosystem. South Bay, the southern most lobe of Flathead Lake, is the most extensive area of shallow water, and therefore, most effected by changes in lake levels. This study began in January of 1984 and was completed in early 1987. Vegetative and structural cover are relatively limited in South Bay, a condition which could contribute to lower recruitment for some fish species. Our data show that the study area contained 0.04% structural and 5.4% vegetative cover in June at fullmore » pool. Both figures are less than 1.0% at minimum pool. Structural complexity mediates the ecological interactions between littoral zone fish and their prey, and can affect local productivity and growth in fish. Structural complexity may also be important to overwinter survival of young perch in Flathead Lake. Winter conditions, including ice cover and fall drawdown, seasonally eliminate the vegetative portion of most rooted macrophytes in South Bay. This results in substantial loss of what little structural cover exists, depriving the perch population of habitat which has been occupied all summer. The loss of cover from draw-down concentrates and probably exposes perch to greater predation, including cannibalism, than would occur if structural complexity were greater. 33 refs., 10 figs., 5 tabs.« less
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2001-06-20
KENNEDY SPACE CENTER, Fla. -- An aerial view of Launch Complex 39 shows the south and west sides of the Vehicle Assembly Building. The curved roadway heading to the VAB leads to the high bay 2, the Safe Haven facility constructed in 2000. The white building in the foreground is the Processing Control Center. Beyond it is the Orbiter Processing Facility, bays 1 and 2. The OPF bay 3 is farther still, closer to the VAB. Farther in the background are the waters of Banana Creek in the Merritt Island National Wildlife Refuge
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Sunendra, Joshi R.; Kukkadapu, Ravi K.; Burdige, David J.
2015-05-19
The Chesapeake Bay, the largest and most productive estuary in the US, suffers from varying degrees of water quality issues fueled by both point and non–point source nutrient sources. Restoration of the bay is complicated by the multitude of nutrient sources, their variable inputs and hydrological conditions, and complex interacting factors including climate forcing. These complexities not only restrict formulation of effective restoration plans but also open up debates on accountability issues with nutrient loading. A detailed understanding of sediment phosphorus (P) dynamics enables one to identify the exchange of dissolved constituents across the sediment- water interface and aid tomore » better constrain mechanisms and processes controlling the coupling between the sediments and the overlying waters. Here we used phosphate oxygen isotope ratios (δ18Op) in concert with sediment chemistry, XRD, and Mössbauer spectroscopy on the sediment retrieved from an organic rich, sulfidic site in the meso-haline portion of the mid-bay to identify sources and pathway of sedimentary P cycling and to infer potential feedback effect on bottom water hypoxia and surface water eutrophication. Isotope data indicate that the regeneration of inorganic P from organic matter degradation (remineralization) is the predominant, if not sole, pathway for authigenic P precipitation in the mid-bay sediments. We interpret that the excess inorganic P generated by remineralization should have overwhelmed any bottom-water and/or pore-water P derived from other sources or biogeochemical processes and exceeded saturation with respect to authigenic P precipitation. It is the first research that identifies the predominance of remineralization pathway against remobilization (coupled Fe-P cycling) pathway in the Chesapeake Bay. Therefore, these results are expected to have significant implications for the current understanding of P cycling and benthic-pelagic coupling in the bay, particularly on the source and pathway of P that sustains hypoxia and supports phytoplankton growth in the surface water.« less
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Bahía de Banderas, Mexico: Morphology, Magnetic Anomalies and Shallow Structure
NASA Astrophysics Data System (ADS)
Mortera Gutiérrez, Carlos A.; Bandy, William L.; Ponce Núñez, Francisco; Pérez Calderón, Daniel A.
2016-10-01
The Bahía de Banderas lies within a tectonically complex area at the northern end of the Middle America Trench. The structure, morphology, subsurface geology and tectonic history of the bay are essential for unraveling the complex tectonic processes occurring in this area. With this focus, marine geophysical data (multi-beam bathymetry, high resolution seismic reflection and total field magnetic data) were collected within the bay and adjacent areas during four campaigns aboard the B.O. EL PUMA conducted in 2006 and 2009. These data image the detailed morphology of, and sedimentation patterns within, the Banderas Canyon (a prominent submarine canyon situated on the south side of the bay) as well as the shallow subsurface structure of the northern part of the bay and the submarine Marietas Ridge, which bounds the bay to the west. We find that the Marietas Ridge is presently a transtensional feature; the course of the Banderas Canyon is controlled by extensive turbidite fan sedimentation in its eastern extremity and by structural lineaments to the west; the canyon floor is filled by sediments and exhibits almost no evidence for recent tectonic movements; the southern canyon wall is quite steep and a few sediments are deposited as submarine fans at the base of the southern wall; and extensive turbidite fans form the lower part of the northern canyon wall, producing a gently sloping lower northern wall. We find no evidence for a regional east-west striking lineament between the bay and the Middle America Trench, which casts doubts on the previous assertion that the Banderas Canyon is unequivocally related to the presence of a regional half-graben. Finally, a N71°E oriented normal fault offsets the seafloor reflector by 15 m within the central part of the bay, suggesting that the bay is currently being subjected to NNW-SSE extension.
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Marine magnetic survey and onshore gravity and magnetic survey, San Pablo Bay, northern California
Ponce, David A.; Denton, Kevin M.; Watt, Janet T.
2016-09-12
IntroductionFrom November 2011 to August 2015, the U.S. Geological Survey (USGS) collected more than 1,000 line-kilometers (length of lines surveyed in kilometers) of marine magnetic data on San Pablo Bay, 98 onshore gravity stations, and over 27 line-kilometers of ground magnetic data in northern California. Combined magnetic and gravity investigations were undertaken to study subsurface geologic structures as an aid in understanding the geologic framework and earthquake hazard potential in the San Francisco Bay Area. Furthermore, marine magnetic data illuminate local subsurface geologic features in the shallow crust beneath San Pablo Bay where geologic exposure is absent.Magnetic and gravity methods, which reflect contrasting physical properties of the subsurface, are ideal for studying San Pablo Bay. Exposed rock units surrounding San Pablo Bay consist mainly of Jurassic Coast Range ophiolite, Great Valley sequence, Franciscan Complex rocks, Miocene sedimentary rocks, and unconsolidated alluvium (Graymer and others, 2006). The contrasting magnetic and density properties of these rocks enable us to map their subsurface extent.
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Sediment calibration strategies of Phase 5 Chesapeake Bay watershed model
Wu, J.; Shenk, G.W.; Raffensperger, Jeff P.; Moyer, D.; Linker, L.C.; ,
2005-01-01
Sediment is a primary constituent of concern for Chesapeake Bay due to its effect on water clarity. Accurate representation of sediment processes and behavior in Chesapeake Bay watershed model is critical for developing sound load reduction strategies. Sediment calibration remains one of the most difficult components of watershed-scale assessment. This is especially true for Chesapeake Bay watershed model given the size of the watershed being modeled and complexity involved in land and stream simulation processes. To obtain the best calibration, the Chesapeake Bay program has developed four different strategies for sediment calibration of Phase 5 watershed model, including 1) comparing observed and simulated sediment rating curves for different parts of the hydrograph; 2) analyzing change of bed depth over time; 3) relating deposition/scour to total annual sediment loads; and 4) calculating "goodness-of-fit' statistics. These strategies allow a more accurate sediment calibration, and also provide some insightful information on sediment processes and behavior in Chesapeake Bay watershed.
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Donatelli, Carmine; Ganju, Neil Kamal; Fagherazzi, Sergio; Leonardi, Nicoletta
2018-01-01
surroundings and are therefore frequently referred to as ecological engineers. The effect of seagrasses on coastal bay resilience and sediment transport dynamics is understudied. Here we use six historical maps of seagrass distribution in Barnegat Bay, USA, to investigate the role of these vegetated surfaces on the sediment storage capacity of shallow bays. Analyses are carried out by means of the Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) numerical modeling framework. Results show that a decline in the extent of seagrass meadows reduces the sediment mass potentially stored within bay systems. The presence of seagrass reduces shear stress values across the entire bay, including unvegetated areas, and promotes sediment deposition on tidal flats. On the other hand, the presence of seagrasses decreases suspended sediment concentrations, which in turn reduces the delivery of sediment to marsh platforms. Results highlight the relevance of seagrasses for the long-term survival of coastal ecosystems, and the complex dynamics regulating the interaction between subtidal and intertidal landscapes.
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Paulson, A.J.
2005-01-01
The concentrations of 22 elements also were measured in the suspended matter of Raritan and Lower New York Bays and brackish water sources. The elemental composition of the suspended matter in surface and bottom waters was correlated with Fe concentrations, which ranged between 50 and 900 μmol g− 1. Statistical differences among the geographical regions were detected in the relationships of Ti, Ni, Co, As, and U with Fe, with particulate As being an especially strong geochemical indicator of Raritan River particles. The geochemical signatures of Lower New York Bay particles were similar to those of Upper New York Bay. The geochemical signatures of Raritan River particles were distinctly different than those of the Upper New York Bay, but the influence of Raritan River particles appeared to be limited to only inner Raritan Bay. This study illustrates the utility of trace elements for characterization of physical processes in complex estuaries.
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NASA Technical Reports Server (NTRS)
Hargis, W. J., Jr.
1981-01-01
The social and economic importance of estuaries are discussed. Major focus is on the Chesapeake Bay and its interaction with the adjacent waters of the Virginia Sea. Associated multiple use development and management problems as well as their internal physical, geological, chemical, and biological complexities are described.
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Evaluation of potential ecological impacts associated with a POTW located on Hempstead Bay, New York
DOE Office of Scientific and Technical Information (OSTI.GOV)
Harman, C.R.; Brockerhoff, F.G.; D`Alleinne, C.P.
1995-12-31
The Hempstead Bay estuary is a broad, shallow complex that is separated from the Atlantic Ocean by a series of barrier islands (Jones and Long Beaches). Hempstead Bay is divided into West Bay, Middle Bay, and East Bay components by a series of marsh islands. The West Bay portion is influenced by tidal exchange through the East Rockaway Inlet. The West Bay in particular, and the Hempstead Bay in general, receive an extensive load of potential contaminants from numerous sources including point and non-point residential and industrial source discharges, storm water runoff, possible migration of leachate from landfills adjacent tomore » the Bay, and the effluent from several wastewater treatment facilities. The objective of this ongoing project is to evaluate whether the operations of a particular wastewater treatment facility located adjacent to the West Bay portion of Hempstead Bay is impacting aquatic resources in the vicinity of the plant. Additionally, there is a concern that potential COIs may be migrating into the West Bay from treatment plant sludge that was used in the construction of a local golf course. The ecological evaluation will consist of a semi-quantitative ecological risk assessment, supported by two rounds of sediment and surface water samples collected from the aquatic environment surrounding the plant and associated areas of interest. Surface water and sediment samples will be analyzed for a variety of parameters including TCL volatile organic compounds, TCL semivolatile organic compounds, TCL pesticides/PCBs and Target Analyte List (TAL) inorganic constituents. The results of that sampling and the preliminary evaluation of the resulting data are presented in this paper.« less
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Ackerman, Joshua T.; Herzog, Mark P.; Hartman, Christopher A.; Watts, Trevor C.; Barr, Jarred R.
2014-01-01
The conversion of 50–90 percent of 15,100 acres of former salt evaporation ponds to tidal marsh habitat in the south San Francisco Bay, California, is planned as part of the South Bay Salt Pond Restoration Project. This large-scale habitat restoration may change the bioavailability of methylmercury. The South Bay already is known to have high methylmercury concentrations, with methylmercury concentrations in several waterbirds species more than known toxicity thresholds where avian reproduction is impaired. In this 2013 study, we continued monitoring bird egg mercury concentrations in response to the restoration of the Pond A8/A7/A5 Complex to a potential tidal marsh in the future. The restoration of the Pond A8/A7/A5 Complex began in autumn 2010, and the Pond A8 Notch was opened 5 feet (one of eight gates) to muted tidal action on June 1, 2011, and then closed in the winter. In autumn 2010, internal levees between Ponds A8, A7, and A5 were breached and water depths were substantially increased by flooding the Pond A8/A7/A5 Complex in February 2011. In June 2012, 15 feet (three of eight gates) of the Pond A8 Notch was opened, and then closed in December 2012. In June 2013, 15 feet of the Pond A8 Notch again was opened, and the Pond A8/A7/A5 Complex was a relatively deep and large pond with muted tidal action in the summer. This report synthesizes waterbird data from the 2013 breeding season, and combines it with our prior study’s data from 2010 and 2011.
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Learning and inference using complex generative models in a spatial localization task.
Bejjanki, Vikranth R; Knill, David C; Aslin, Richard N
2016-01-01
A large body of research has established that, under relatively simple task conditions, human observers integrate uncertain sensory information with learned prior knowledge in an approximately Bayes-optimal manner. However, in many natural tasks, observers must perform this sensory-plus-prior integration when the underlying generative model of the environment consists of multiple causes. Here we ask if the Bayes-optimal integration seen with simple tasks also applies to such natural tasks when the generative model is more complex, or whether observers rely instead on a less efficient set of heuristics that approximate ideal performance. Participants localized a "hidden" target whose position on a touch screen was sampled from a location-contingent bimodal generative model with different variances around each mode. Over repeated exposure to this task, participants learned the a priori locations of the target (i.e., the bimodal generative model), and integrated this learned knowledge with uncertain sensory information on a trial-by-trial basis in a manner consistent with the predictions of Bayes-optimal behavior. In particular, participants rapidly learned the locations of the two modes of the generative model, but the relative variances of the modes were learned much more slowly. Taken together, our results suggest that human performance in a more complex localization task, which requires the integration of sensory information with learned knowledge of a bimodal generative model, is consistent with the predictions of Bayes-optimal behavior, but involves a much longer time-course than in simpler tasks.
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Monitoring of oceanographic properties of Glacier Bay, Alaska 2004
Madison, Erica N.; Etherington, Lisa L.
2005-01-01
Glacier Bay is a recently (300 years ago) deglaciated fjord estuarine system that has multiple sills, very deep basins, tidewater glaciers, and many streams. Glacier Bay experiences a large amount of runoff, high sedimentation, and large tidal variations. High freshwater discharge due to snow and ice melt and the presence of the tidewater glaciers makes the bay extremely cold. There are many small- and large-scale mixing and upwelling zones at sills, glacial faces, and streams. The complex topography and strong currents lead to highly variable salinity, temperature, sediment, primary productivity, light penetration, stratification levels, and current patterns within a small area. The oceanographic patterns within Glacier Bay drive a large portion of the spatial and temporal variability of the ecosystem. It has been widely recognized by scientists and resource managers in Glacier Bay that a program to monitor oceanographic patterns is essential for understanding the marine ecosystem and to differentiate between anthropogenic disturbance and natural variation. This year’s sampling marks the 12th continuous year of monitoring the oceanographic conditions at 23 stations along the primary axes within Glacier Bay, AK, making this a very unique and valuable data set in terms of its spatial and temporal coverage.
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Macrobenthos of Yenisei Bay and the adjacent Kara Sea shelf
NASA Astrophysics Data System (ADS)
Galkin, S. V.; Vedenin, A. A.
2015-07-01
Trawl samples were collected in the northern region of Yenisei Bay and adjacent parts of the Kara Sea shelf. A total of eight stations were taken. We found more than 200 species of benthic organisms. A consecutive replacement of benthic communities is observed when going to the north from the Ob and Yenisei estuaries to the open parts of the sea. We could distinguish four different species complexes in the investigated area: a brackish-water complex where Saduria entomon is dominant; an intermediate complex where S. sibirica, S. sabini and Portlandia aestuariorum are dominant; a transitional complex with P. arctica as a dominant species and with a small amount of Ophiocten sericeum; a marine complex where O. sericeum is dominant. When salinity increased, some brackish-water species were replaced by related euryhaline species. One such example was the replacement of brackish-water Saduria entomon isopods by two euryhaline species: S. sibirica and S. sabini. The consecutive replacement of benthic communities showed a break near Sverdrup Island. In this area the marine complex was replaced by a transitional complex with P. arctica.
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Baron, Anna P; von Schubert, Conrad; Cubizolles, Fabien; Siemeister, Gerhard; Hitchcock, Marion; Mengel, Anne; Schröder, Jens; Fernández-Montalván, Amaury; von Nussbaum, Franz; Mumberg, Dominik; Nigg, Erich A
2016-01-01
The kinase Bub1 functions in the spindle assembly checkpoint (SAC) and in chromosome congression, but the role of its catalytic activity remains controversial. Here, we use two novel Bub1 inhibitors, BAY-320 and BAY-524, to demonstrate potent Bub1 kinase inhibition both in vitro and in intact cells. Then, we compared the cellular phenotypes of Bub1 kinase inhibition in HeLa and RPE1 cells with those of protein depletion, indicative of catalytic or scaffolding functions, respectively. Bub1 inhibition affected chromosome association of Shugoshin and the chromosomal passenger complex (CPC), without abolishing global Aurora B function. Consequently, inhibition of Bub1 kinase impaired chromosome arm resolution but exerted only minor effects on mitotic progression or SAC function. Importantly, BAY-320 and BAY-524 treatment sensitized cells to low doses of Paclitaxel, impairing both chromosome segregation and cell proliferation. These findings are relevant to our understanding of Bub1 kinase function and the prospects of targeting Bub1 for therapeutic applications. DOI: http://dx.doi.org/10.7554/eLife.12187.001 PMID:26885717
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NASA Astrophysics Data System (ADS)
Donatelli, Carmine; Ganju, Neil Kamal; Fagherazzi, Sergio; Leonardi, Nicoletta
2018-05-01
Seagrasses are marine flowering plants that strongly impact their physical and biological surroundings and are therefore frequently referred to as ecological engineers. The effect of seagrasses on coastal bay resilience and sediment transport dynamics is understudied. Here we use six historical maps of seagrass distribution in Barnegat Bay, USA, to investigate the role of these vegetated surfaces on the sediment storage capacity of shallow bays. Analyses are carried out by means of the Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) numerical modeling framework. Results show that a decline in the extent of seagrass meadows reduces the sediment mass potentially stored within bay systems. The presence of seagrass reduces shear stress values across the entire bay, including unvegetated areas, and promotes sediment deposition on tidal flats. On the other hand, the presence of seagrasses decreases suspended sediment concentrations, which in turn reduces the delivery of sediment to marsh platforms. Results highlight the relevance of seagrasses for the long-term survival of coastal ecosystems, and the complex dynamics regulating the interaction between subtidal and intertidal landscapes.
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2012-09-20
CAPE CANAVERAL, Fla. – Inside Orbiter Processing Facility-2 at NASA’s Kennedy Space Center in Florida, workers watch as the left payload bay door begins to close on space shuttle Atlantis. Both payload bay doors will be closed for the final time. The orbiter is undergoing final preparations for its transfer to the Kennedy Space Center Visitor complex targeted for November. The work is part of Transition and Retirement of the remaining shuttle. Atlantis is being prepared for public display at the visitor complex. Over the course of its 26-year career, Atlantis spent 293 days in space during 33 missions. For more information, visit http://www.nasa.gov/transition. Photo credit: NASA/Jim Grossmann
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2012-09-20
CAPE CANAVERAL, Fla. – Inside Orbiter Processing Facility-2 at NASA’s Kennedy Space Center in Florida, space shuttle Atlantis’ left payload bay door has been closed. Both payload bay doors will be closed for the final time. The orbiter is undergoing final preparations for its transfer to the Kennedy Space Center Visitor complex targeted for November. The work is part of Transition and Retirement of the remaining shuttle. Atlantis is being prepared for public display at the visitor complex. Over the course of its 26-year career, Atlantis spent 293 days in space during 33 missions. For more information, visit http://www.nasa.gov/transition. Photo credit: NASA/Jim Grossmann
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Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS, HIGH BAY AREA. ...
Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS, HIGH BAY AREA. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. TRANSFER AISLE NORTH DOOR,ARCHITECTURAL NORTH ELEVATION AND MISC. DETAILS. Sheet 78 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL
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Frère, L; Paul-Pont, I; Rinnert, E; Petton, S; Jaffré, J; Bihannic, I; Soudant, P; Lambert, C; Huvet, A
2017-06-01
The concentration and spatial distribution of microplastics in the Bay of Brest (Brittany, France) was investigated in two surveys. Surface water and sediment were sampled at nine locations in areas characterized by contrasting anthropic pressures, riverine influences or water mixing. Microplastics were categorized by their polymer type and size class. Microplastic contamination in surface water and sediment was dominated by polyethylene fragments (PE, 53-67%) followed by polypropylene (PP, 16-30%) and polystyrene (PS, 16-17%) microparticles. The presence of buoyant microplastics (PE, PP and PS) in sediment suggests the existence of physical and/or biological processes leading to vertical transfer of lightweight microplastics in the bay. In sediment (upper 5 cm), the percentage of particles identified by Raman micro-spectroscopy was lower (41%) than in surface water (79%) and may explain the apparent low concentration observed in this matrix (0.97 ± 2.08 MP kg -1 dry sediment). Mean microplastic concentration was 0.24 ± 0.35 MP m -3 in surface water. We suggest that the observed spatial MP distribution is related to proximity to urbanized areas and to hydrodynamics in the bay. A particle dispersal model was used to study the influence of hydrodynamics on surface microplastic distribution. The outputs of the model showed the presence of a transitional convergence zone in the centre of the bay during flood tide, where floating debris coming from the northern and southern parts of the bay tends to accumulate before being expelled from the bay. Further modelling work and observations integrating (i) the complex vertical motion of microplastics, and (ii) their point sources is required to better understand the fate of microplastics in such a complex coastal ecosystem. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Kearney, Kelly A; Butler, Mark; Glazer, Robert; Kelble, Christopher R; Serafy, Joseph E; Stabenau, Erik
2015-04-01
The Florida Bay ecosystem supports a number of economically important ecosystem services, including several recreational fisheries, which may be affected by changing salinity and temperature due to climate change. In this paper, we use a combination of physical models and habitat suitability index models to quantify the effects of potential climate change scenarios on a variety of juvenile fish and lobster species in Florida Bay. The climate scenarios include alterations in sea level, evaporation and precipitation rates, coastal runoff, and water temperature. We find that the changes in habitat suitability vary in both magnitude and direction across the scenarios and species, but are on average small. Only one of the seven species we investigate (Lagodon rhomboides, i.e., pinfish) sees a sizable decrease in optimal habitat under any of the scenarios. This suggests that the estuarine fauna of Florida Bay may not be as vulnerable to climate change as other components of the ecosystem, such as those in the marine/terrestrial ecotone. However, these models are relatively simplistic, looking only at single species effects of physical drivers without considering the many interspecific interactions that may play a key role in the adjustment of the ecosystem as a whole. More complex models that capture the mechanistic links between physics and biology, as well as the complex dynamics of the estuarine food web, may be necessary to further understand the potential effects of climate change on the Florida Bay ecosystem.
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NASA Astrophysics Data System (ADS)
Kearney, Kelly A.; Butler, Mark; Glazer, Robert; Kelble, Christopher R.; Serafy, Joseph E.; Stabenau, Erik
2015-04-01
The Florida Bay ecosystem supports a number of economically important ecosystem services, including several recreational fisheries, which may be affected by changing salinity and temperature due to climate change. In this paper, we use a combination of physical models and habitat suitability index models to quantify the effects of potential climate change scenarios on a variety of juvenile fish and lobster species in Florida Bay. The climate scenarios include alterations in sea level, evaporation and precipitation rates, coastal runoff, and water temperature. We find that the changes in habitat suitability vary in both magnitude and direction across the scenarios and species, but are on average small. Only one of the seven species we investigate ( Lagodon rhomboides, i.e., pinfish) sees a sizable decrease in optimal habitat under any of the scenarios. This suggests that the estuarine fauna of Florida Bay may not be as vulnerable to climate change as other components of the ecosystem, such as those in the marine/terrestrial ecotone. However, these models are relatively simplistic, looking only at single species effects of physical drivers without considering the many interspecific interactions that may play a key role in the adjustment of the ecosystem as a whole. More complex models that capture the mechanistic links between physics and biology, as well as the complex dynamics of the estuarine food web, may be necessary to further understand the potential effects of climate change on the Florida Bay ecosystem.
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Cronin, Thomas M.; Willard, Debra A.; Phillips, Scott
2000-01-01
Chesapeake Bay, the Nation’s largest and most productive estuary (fig. 1), faces complex environmental issues related to nutrients and oxygen, turbidity and sedimentation, toxic dinoflagellates, sea-level rise, and coastal erosion. The Chesapeake Bay Program (CBP) is a partnership among the Chesapeake Bay Commission, the Federal Government, the District of Columbia, and the States of Maryland, Virginia, and Pennsylvania. The CBP is working to preserve, restore, and protect the bay’s living resources, vital habitats, and water quality, to protect human health, and to promote sound land-use policies in the watershed. The CBP began to set restoration goals for the ecosystem in the mid-1980’s and is now refining current goals and setting new ones as part of a new bay agreement— Chesapeake 2000. As the CBP sets restoration goals for the next 10–20 years, it will be critical to understand the long-term changes of the bay ecosystem due to climate variability and the influence of past and future human activities.For the past 4 years, the U.S. Geological Survey (USGS) has been engaged in research designed to provide objective scientific answers to questions about long-term changes in the bay ecosystem: What paleoecological and geochemical methods are best for documenting trends in the bay ecosystem?How does climate variability, including drought, affect the bay?What are historical trends in dissolved oxygen?What is the relationship between sedimentation and water clarity, and what is the effect of turbidity on living resources?How have past land-use changes affected bay habitats and living resources?
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Geologic map of the San Francisco Bay region
Graymer, R.W.; Moring, B.C.; Saucedo, G.J.; Wentworth, C.M.; Brabb, E.E.; Knudsen, K. L.
2006-01-01
The rocks and fossils of the San Francisco Bay region reveal that the geology there is the product of millions of years at the active western margin of North America. The result of this history is a complex mosaic of geologic materials and structures that form the landscape. A geologic map is one of the basic tools to understand the geology, geologic hazards, and geologic history of a region.With heightened public awareness about earthquake hazards leading up to the 100th anniversary of the 1906 San Francisco earthquake, the U.S. Geological Survey (USGS) is releasing new maps of the San Francisco Bay Area designed to give residents and others a new look at the geologic history and hazards of the region. The “Geologic Map of the San Francisco Bay region” shows the distribution of geologic materials and structures, demonstrates how geologists study the age and origin of the rocks and deposits that we live on, and reveals the complicated geologic history that has led to the landscape that shapes the Bay Area.
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Seagrass morphometrics at species level in Moreton Bay, Australia from 2012 to 2013.
Samper-Villarreal, Jimena; Roelfsema, Chris; Kovacs, Eva M; Adi, Novi S; Lyons, Mitchell; Mumby, Peter J; Lovelock, Catherine E; Saunders, Megan I; Phinn, Stuart R
2017-05-09
Seagrass above, below and total biomass, density and leaf area, length and width were quantified at a species level for 122 sites over three sampling periods in Moreton Bay, Australia. Core samples were collected in two regions: (1) a high water quality region with varying species assemblages and canopy complexity (98 sites); and (2) along a turbidity gradient in the bay (24 sites within four locations). Core samples were collected using a 15 cm diameter×20 cm long corer. Seagrass dry biomass per component was quantified per species present in each sample. A total of 220 biomass and density data records are included, 130 from the high water quality region and 90 from the turbidity gradient. These data provide a detailed assessment of biomass, density and leaf metrics per species sampled from Moreton Bay over 2012-2013. In future, these can be used as a baseline to assess seasonal and spatial variation within the bay, within the region and among regions.
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Seagrass morphometrics at species level in Moreton Bay, Australia from 2012 to 2013
Samper-Villarreal, Jimena; Roelfsema, Chris; Kovacs, Eva M.; Adi, Novi S.; Lyons, Mitchell; Mumby, Peter J.; Lovelock, Catherine E.; Saunders, Megan I.; Phinn, Stuart R.
2017-01-01
Seagrass above, below and total biomass, density and leaf area, length and width were quantified at a species level for 122 sites over three sampling periods in Moreton Bay, Australia. Core samples were collected in two regions: (1) a high water quality region with varying species assemblages and canopy complexity (98 sites); and (2) along a turbidity gradient in the bay (24 sites within four locations). Core samples were collected using a 15 cm diameter×20 cm long corer. Seagrass dry biomass per component was quantified per species present in each sample. A total of 220 biomass and density data records are included, 130 from the high water quality region and 90 from the turbidity gradient. These data provide a detailed assessment of biomass, density and leaf metrics per species sampled from Moreton Bay over 2012–2013. In future, these can be used as a baseline to assess seasonal and spatial variation within the bay, within the region and among regions. PMID:28485717
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Hampton roads regional Water-Quality Monitoring Program
Porter, Aaron J.; Jastram, John D.
2016-12-02
IntroductionHow much nitrogen, phosphorus, and suspended solids are contributed by the highly urbanized areas of the Hampton Roads region in Virginia to Chesapeake Bay? The answer to this complex question has major implications for policy decisions, resource allocations, and efforts aimed at restoring clean waters to Chesapeake Bay and its tributaries. To quantify the amount of nitrogen, phosphorus, and suspended solids delivered to the bay from this region, the U.S. Geological Survey has partnered with the Hampton Roads Sanitation District (HRSD), in cooperation with the Hampton Roads Planning District Commission (HRPDC), to conduct a water-quality monitoring program throughout the Hampton Roads region.
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Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS, HIGH BAY AREA. ...
Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS, HIGH BAY AREA. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. TRANSFER AISLE NORTH DOOR, ARCHITECTURAL AND STRUCTURAL ELEVATIONS, SECTIONS AND DETAILS. Sheet 79 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL
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NASA Astrophysics Data System (ADS)
Lamour, B. G.; Harris, R. T.; Roberts, A. G.
2010-06-01
Power system reliability problems are very difficult to solve because the power systems are complex and geographically widely distributed and influenced by numerous unexpected events. It is therefore imperative to employ the most efficient optimization methods in solving the problems relating to reliability of the power system. This paper presents a reliability analysis and study of the power interruptions resulting from severe power outages in the Nelson Mandela Bay Municipality (NMBM), South Africa and includes an overview of the important factors influencing reliability, and methods to improve the reliability. The Blue Horizon Bay 22 kV overhead line, supplying a 6.6 kV residential sector has been selected. It has been established that 70% of the outages, recorded at the source, originate on this feeder.
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Model and algorithm for container ship stowage planning based on bin-packing problem
NASA Astrophysics Data System (ADS)
Zhang, Wei-Ying; Lin, Yan; Ji, Zhuo-Shang
2005-09-01
In a general case, container ship serves many different ports on each voyage. A stowage planning for container ship made at one port must take account of the influence on subsequent ports. So the complexity of stowage planning problem increases due to its multi-ports nature. This problem is NP-hard problem. In order to reduce the computational complexity, the problem is decomposed into two sub-problems in this paper. First, container ship stowage problem (CSSP) is regarded as “packing problem”, ship-bays on the board of vessel are regarded as bins, the number of slots at each bay are taken as capacities of bins, and containers with different characteristics (homogeneous containers group) are treated as items packed. At this stage, there are two objective functions, one is to minimize the number of bays packed by containers and the other is to minimize the number of overstows. Secondly, containers assigned to each bays at first stage are allocate to special slot, the objective functions are to minimize the metacentric height, heel and overstows. The taboo search heuristics algorithm are used to solve the subproblem. The main focus of this paper is on the first subproblem. A case certifies the feasibility of the model and algorithm.
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Structure, stratigraphy, and eruption dynamics of a young tuff ring: Hanauma Bay, O'ahu, Hawai'i
NASA Astrophysics Data System (ADS)
Rottas, K. M.; Houghton, B. F.
2012-09-01
The Hanauma Bay-Koko Head complex is one of several young volcanic landforms along the Koko fissure, in southeastern O'ahu. The Hanauma Bay region of the complex comprises two nested tuff rings, inner and outer Hanauma Bay, and multiple smaller vents. The internal structure of the inner tuff ring, well exposed due to subsequent breaching by the ocean and wave erosion, indicates that it formed during a minimum of five distinct phases of deposition that produced five mappable units. Significant inward collapses generated major unconformities that separate the units exposed in the inner wall. The planes of failure are cut by narrow steep-walled, locally overhung channels and gullies, suggesting that the collapse events were each followed by short time breaks during which the deposits were eroded by rainfall runoff. Within each pyroclastic unit, there are many local slump scars and unconformities, suggesting that minor instability of the inner wall was a near-constant feature. From bedding sags and surge bed forms, it is apparent that the vent shifted at least twice during tuff ring growth. Ballistic blocks in the youngest unit indicate that the eruption overlapped in time with a separate eruption to the north, most likely to be that of the Kahauloa tuff ring 880 m away.
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Admiralty Bay Benthos Diversity—A census of a complex polar ecosystem
NASA Astrophysics Data System (ADS)
Siciński, Jacek; Jażdżewski, Krzysztof; Broyer, Claude De; Presler, Piotr; Ligowski, Ryszard; Nonato, Edmundo F.; Corbisier, Thais N.; Petti, Monica A. V.; Brito, Tania A. S.; Lavrado, Helena P.; BŁażewicz-Paszkowycz, Magdalena; Pabis, Krzysztof; Jażdżewska, Anna; Campos, Lucia S.
2011-03-01
A thorough census of Admiralty Bay benthic biodiversity was completed through the synthesis of data, acquired from more than 30 years of observations. Most of the available records arise from successive Polish and Brazilian Antarctic expeditions organized since 1977 and 1982, respectively, but also include new data from joint collecting efforts during the International Polar Year (2007-2009). Geological and hydrological characteristics of Admiralty Bay and a comprehensive species checklist with detailed data on the distribution and nature of the benthic communities are provided. Approximately 1300 species of benthic organisms (excluding bacteria, fungi and parasites) were recorded from the bay's entire depth range (0-500 m). Generalized classifications and the descriptions of soft-bottom and hard-bottom invertebrate communities are presented. A time-series analysis showed seasonal and interannual changes in the shallow benthic communities, likely to be related to ice formation and ice melt within the bay. As one of the best studied regions in the maritime Antarctic Admiralty Bay represents a legacy site, where continued, systematically integrated data sampling can evaluate the effects of climate change on marine life. Both high species richness and high assemblage diversity of the Admiralty Bay shelf benthic community have been documented against the background of habitat heterogeneity.
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Results of complex annual parasitological monitoring in the coastal area of Kola Bay
NASA Astrophysics Data System (ADS)
Kuklin, V. V.; Kuklina, M. M.; Kisova, N. E.; Maslich, M. A.
2009-12-01
The results of annual parasitological monitoring in the coastal area near the Abram-mys (Kola Bay, Barents Sea) are presented. The studies were performed in 2006-2007 and included complex examination of the intermediate hosts (mollusks and crustaceans) and definitive hosts (marine fish and birds) of the helminths. The biodiversity of the parasite fauna, seasonal dynamics, and functioning patterns of the parasite systems were investigated. The basic regularities in parasite circulation were assessed in relation to their life cycle strategies and the ecological features of the intermediate and definitive hosts. The factors affecting the success of parasite circulation in the coastal ecosystems were revealed through analysis of parasite biodiversity and abundance dynamics.
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Prediction of outcome in multiorgan resections for cancer using a bayes-network.
Udelnow, Andrej; Leinung, Steffen; Grochola, Lukasz Filipp; Henne-Bruns, Doris; Wfcrl, Peter
2013-01-01
The long-term success of multivisceral resections for cancer is difficult to forecast due to the complexity of factors influencing the prognosis. The aim of our study was to assess the predictivity of a Bayes network for the postoperative outcome and survival. We included each oncologic patient undergoing resection of 4 or more organs from 2002 till 2005 at the Ulm university hospital. Preoperative data were assessed as well as the tumour classification, the resected organs, intra- and postoperative complications and overall survival. Using the Genie 2.0 software we developed a Bayes network. Multivisceral tumour resections were performed in 22 patients. The receiver operating curve areas of the variables "survival >12 months" and "hospitalisation >28 days" as predicted by the Bayes network were 0.81 and 0.77 and differed significantly from 0.5 (p: 0.019 and 0.028, respectively). The positive predictive values of the Bayes network for these variables were 1 and 0.8 and the negative ones 0.71 and 0.88, respectively. Bayes networks are useful for the prognosis estimation of individual patients and can help to decide whether to perform a multivisceral resection for cancer.
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Edquist, Jessica; Rudin-Brown, Christina M; Lenné, Michael G
2012-03-01
On-street parking is associated with elevated crash risk. It is not known how drivers' mental workload and behaviour in the presence of on-street parking contributes to, or fails to reduce, this increased crash risk. On-street parking tends to co-exist with visually complex streetscapes that may affect workload and crash risk in their own right. The present paper reports results from a driving simulator study examining the effects of on-street parking and road environment visual complexity on driver behaviour and surrogate measures of crash risk. Twenty-nine participants drove a simulated urban commercial and arterial route. Compared to sections with no parking bays or empty parking bays, in the presence of occupied parking bays drivers lowered their speed and shifted their lateral position towards roadway centre to compensate for the higher mental workload they reported experiencing. However, this compensation was not sufficient to reduce drivers' reaction time on a safety-relevant peripheral detection task or to an unexpected pedestrian hazard. Compared to the urban road environments, the less visually complex arterial road environment was associated with speeds that were closer to the posted limit, lower speed variability and lower workload ratings. These results support theoretical positions that proffer workload as a mediating variable of speed choice. However, drivers in this study did not modify their speed sufficiently to maintain safe hazard response times in complex environments with on-street parking. This inadequate speed compensation is likely to affect real world crash risk. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Bay Breeze Influence on Surface Ozone at Edgewood, MD During July 2011
NASA Technical Reports Server (NTRS)
Stauffer, Ryan M.; Thompson, Anne M.; Martins, Douglas K.; Clark, Richard D.; Goldberg, Daniel L.; Loughner, Christopher P.; Delgado, Ruben; Dickerson, Russell R.; Stehr, Jeffrey W.; Tzortziou, Maria A.
2012-01-01
Surface ozone (O3) was analyzed to investigate the role of the bay breeze on air quality at two locations in Edgewood, Maryland (lat: 39.4deg, lon: -76.3deg) for the month of July 2011. Measurements were taken as part of the first year of NASA's "Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality" (DISCOVER-AQ) Earth Venture campaign and as part of NASA's Geostationary for Coastal and Air Pollution Events Chesapeake Bay Oceanographic campaign with DISCOVER-AQ (Geo-CAPE CBODAQ). Geo-CAPE CBODAQ complements DISCOVER-AQ by providing ship-based observations over the Chesapeake Bay. A major goal of DISCOVER-AQ is determining the relative roles of sources, photochemistry and local meteorology during air quality events in the Mid-Atlantic region of the U.S. Surface characteristics, transport and vertical structures of O3 during bay breezes were identified using in-situ surface, balloon and aircraft data, along with remote sensing equipment. Localized late day peaks in O3 were observed during bay breeze days, maximizing an average of 3 h later compared to days without bay breezes. Of the 10 days of July 2011 that violated the U.S. Environmental Protection Agency (EPA) 8 h O3 standard of 75 parts per billion by volume (ppbv) at Edgewood, eight exhibited evidence of a bay breeze circulation. The results indicate that while bay breezes and the processes associated with them are not necessary to cause exceedances in this area, bay breezes exacerbate poor air quality that sustains into the late evening hours at Edgewood. The vertical and horizontal distributions of O3 from the coastal Edgewood area to the bay also show large gradients that are often determined by boundary layer stability. Thus, developing air quality models that can sufficiently resolve these dynamics and associated chemistry, along with more consistent monitoring of O3 and meteorology on and along the complex coastline of Chesapeake Bay must be a high priority.
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Crustal structure of the coastal and marine San Francisco Bay region, California
Parsons, Tom
2002-01-01
In summary, these studies were carried out in an environment where background information on faults in the San Francisco Bay region was sought. Much of the structural information presented here comes from experiments of a style unlikely to be conducted by the USGS in the near future. Together, the chapters in this volume provide a structural framework for a major part of a complex strike-slip fault system.
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ERIC Educational Resources Information Center
Shettler, James
Project MER (Marine Ecology Research) is aimed at improving environmental education in the San Francisco Bay Area schools. As part of meeting this goal, it is hoped that students and teachers can see the results of their efforts being put to practical use. This guide is the third of a series produced to help students and teachers gather data…
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NASA Astrophysics Data System (ADS)
Afife, M.; Salem, M.; Aziz, M. Abdel
2017-07-01
Zeit Bay Field is one of the most important oil-bearing fields in the Gulf of Suez, Egypt, producing oil from the fractured basement rocks. Due to the complex structural setting of the area and the classical exploration concept that was based mainly on 2D seismic survey data, the area suffered from limited hydrocarbon interest for several years. During this time, most of the drilled wells hit structural highs and resulted in several dry holes. The present study is based on the interpretation of more recently acquired 3D seismic survey data as, matched with the available well logs, used to understand the complex structural setting of the Zeit Bay Field and provide insight into the entrapment style of the implied hydrocarbons. Several selected seismic cross sections were constructed, to extract subsurface geologic information, using available seismic profiles and wells. In addition, structure contour maps (isochronous maps, converted to depth maps) were constructed for the peaks of the basement, Nubian Sandstone, Kareem and Belayim Formations. Folds (anticlines and synclines) and faults (dip-slip) are identified on these maps, both individually and in groups, giving rise to step-like belts, as well as graben and horst blocks.
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Physical oceanographic investigation of Massachusetts and Cape Cod Bays
Geyer, W. Rockwell; Gardner, George B.; Brown, Wendell S.; Irish, James D.; Butman, Bradford; Loder, T.C.; Signell, Richard P.
1992-01-01
This physical oceanographic study of the Massachusetts Bays (fig. 1) was designed to provide for the first time a bay-wide description of the circulation and mixing processes on a seasonal basis. Most of the measurements were conducted between April 1990 and June 1991 and consisted of moored observations to study the current flow patterns (fig. 2), hydrographic surveys to document the changes in water properties (fig. 3), high-resolution surveys of velocity and water properties to provide information on the spatial variability of the flow, drifter deployments to measure the currents, and acquisition of satellite images to provide a bay-wide picture of the surface temperature and its spatial variability. A longterm objective of the Massachusetts Bays program is to develop an understanding of the transport of water, dissolved substances and particles throughout the bays. Because horizontal and vertical transport is important to biological, chemical, and geological processes in Massachusetts and Cape Cod Bays, this physical oceanographic study will have broad application and will improve the ability to manage and monitor the water and sediment quality of the Bays. Key results are:There is a marked seasonal variation in stratification in the bays, from well mixed conditions during the winter to strong stratification in the summertime. The stratification acts as a partial barrier to exchange between the surface waters and the deeper waters and causes the motion of the surface waters to be decoupled from the more sluggish flow of the deep waters. During much of the year, there is weak but persistent counterclockwise flow around the bays, made up of southwesterly flow past Cape Ann, southward flow along the western shore, and outflow north of Race Point. The data suggest that this residual flow pattern reverses in fall. Fluctuations caused by wind and density variations are typically larger than the long-term mean. With the exception of western Massachusetts Bay, flushing of the Bays is largely the result of the mean throughflow. Residence time estimates of the surface waters range from 20-45 days. The deeper water has a longer residence time, but its value is difficult to estimate. There is evidence that the deep waters in Stellwagen Basin are not renewed between the onset of stratification and the fall cooling period.Current measurements made near the new outfall site in western Massachusetts Bay suggest that water and material discharged there are not swept away in a consistent direction by a well-defined steady current but are mixed and transported by a variety of processes, including the action of tides, winds, and river inflow. One-day particle excursions are typically less than 10 km. The outfall is apparently located in a region to the west of the basin-wide residual flow pattern.Observations in western Massachusetts Bay, near the location of the future Boston sewage outfall, show that the surficial sediments are episodically resuspended from the seafloor during storms. The observations suggest onshore transport of suspended material during tranquil periods and episodic offshore and southerly alongshore transport of resuspended sediments during storms. The spatial complexity of the flow in the Massachusetts Bays is typical of nearshore areas that have irregular coastal shorelines and topography and currents that are forced locally by wind and river runoff as well as by the flow in adjacent regions. Numerical models are providing a mechanism to interpret the complex spatial flow patterns that cannot be completely resolved by field observations and to investigate key physical processes that control the physics of water and particle transport.
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Kusky, Timothy M.; Bradley, Dwight C.; Haeussler, Peter J.; Karl, Susan M.
1997-01-01
Controls on accretion of flysch and melange terranes at convergent margins are poorly understood. Southern Alaska's Chugach terrane forms the outboard accretionary margin of the Wrangellia composite terrane, and consists of two major lithotectonic units, including Triassic-Cretaceous melange of the McHugh Complex and Late Cretaceous flysch of the Valdez Group. The contact between the McHugh Complex and the Valdez Group on the Kenai Peninsula is a tectonic boundary between chaotically deformed melange of argillite, chert, greenstone, and graywacke of the McHugh Complex and a less chaotically deformed melange of argillite and graywacke of the Valdez Group. We assign the latter to a new, informal unit of formational rank, the Iceworm melange, and interpret it as a contractional fault zone (Chugach Bay thrust) along which the Valdez Group was emplaced beneath the McHugh Complex. The McHugh Complex had already been deformed and metamorphosed to prehnite-pumpellyite facies prior to formation of the Iceworm melange. The Chugach Bay thrust formed between 75 and 55 Ma, as shown by Campanian-Maastrichtian depositional ages of the Valdez Group, and fault-related fabrics in the Iceworm melange that are cut by Paleocene dikes. Motion along the Chugach Bay thrust thus followed Middle to Late Cretaceous collision (circa 90-100 Ma) of the Wrangellia composite terrane with North America. Collision related uplift and erosion of mountains in British Columbia formed a submarine fan on the Farallon plate, and we suggest that attempted subduction of this fan dramatically changed the subduction/accretion style within the Chugach accretionary wedge. We propose a model in which subduction of thinly sedimented plates concentrates shear strains in a narrow zone, generating melanges like the McHugh in accretionary complexes. Subduction of thickly sedimented plates allows wider distribution of shear strains to accommodate plate convergence, generating a more coherent accretionary style including the fold-thrust structures that dominate the outcrop pattern in the Valdez belt. Rapid underplating and frontal accretion of the Valdez Group caused a critical taper adjustment of the accretionary wedge, including exhumation of the metamorphosed McHugh Complex, and its emplacement over the Valdez Group. The Iceworm melange formed in a zone of focused fluid flow at the boundary between the McHugh Complex and Valdez Group during this critical taper adjustment of the wedge to these changing boundary conditions.
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NASA Astrophysics Data System (ADS)
Kusky, Timothy M.; Bradley, Dwight C.; Haeussler, Peter J.; Karl, Sue
1997-12-01
Controls on accretion of flysch and mélange terranes at convergent margins are poorly understood. Southern Alaska's Chugach terrane forms the outboard accretionary margin of the Wrangellia composite terrane, and consists of two major lithotectonic units, including Triassic-Cretaceous mélange of the McHugh Complex and Late Cretaceous flysch of the Valdez Group. The contact between the McHugh Complex and the Valdez Group on the Kenai Peninsula is a tectonic boundary between chaotically deformed melange of argillite, chert, greenstone, and graywacke of the McHugh Complex and a less chaotically deformed mélange of argillite and graywacke of the Valdez Group. We assign the latter to a new, informal unit of formational rank, the Iceworm mélange, and interpret it as a contractional fault zone (Chugach Bay thrust) along which the Valdez Group was emplaced beneath the McHugh Complex. The McHugh Complex had already been deformed and metamorphosed to prehnite-pumpellyite facies prior to formation of the Iceworm mélange. The Chugach Bay thrust formed between 75 and 55 Ma, as shown by Campanian-Maastrichtian depositional ages of the Valdez Group, and fault-related fabrics in the Iceworm mélange that are cut by Paleocene dikes. Motion along the Chugach Bay thrust thus followed Middle to Late Cretaceous collision (circa 90-100 Ma) of the Wrangellia composite terrane with North America. Collision related uplift and erosion of mountains in British Columbia formed a submarine fan on the Farallon plate, and we suggest that attempted subduction of this fan dramatically changed the subduction/accretion style within the Chugach accretionary wedge. We propose a model in which subduction of thinly sedimented plates concentrates shear strains in a narrow zone, generating mélanges like the McHugh in accretionary complexes. Subduction of thickly sedimented plates allows wider distribution of shear strains to accommodate plate convergence, generating a more coherent accretionary style including the fold-thrust structures that dominate the outcrop pattern in the Valdez belt. Rapid underplating and frontal accretion of the Valdez Group caused a critical taper adjustment of the accretionary wedge, including exhumation of the metamorphosed McHugh Complex, and its emplacement over the Valdez Group. The Iceworm mélange formed in a zone of focused fluid flow at the boundary between the McHugh Complex and Valdez Group during this critical taper adjustment of the wedge to these changing boundary conditions.
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Assawamakin, Anunchai; Prueksaaroon, Supakit; Kulawonganunchai, Supasak; Shaw, Philip James; Varavithya, Vara; Ruangrajitpakorn, Taneth; Tongsima, Sissades
2013-01-01
Identification of suitable biomarkers for accurate prediction of phenotypic outcomes is a goal for personalized medicine. However, current machine learning approaches are either too complex or perform poorly. Here, a novel two-step machine-learning framework is presented to address this need. First, a Naïve Bayes estimator is used to rank features from which the top-ranked will most likely contain the most informative features for prediction of the underlying biological classes. The top-ranked features are then used in a Hidden Naïve Bayes classifier to construct a classification prediction model from these filtered attributes. In order to obtain the minimum set of the most informative biomarkers, the bottom-ranked features are successively removed from the Naïve Bayes-filtered feature list one at a time, and the classification accuracy of the Hidden Naïve Bayes classifier is checked for each pruned feature set. The performance of the proposed two-step Bayes classification framework was tested on different types of -omics datasets including gene expression microarray, single nucleotide polymorphism microarray (SNParray), and surface-enhanced laser desorption/ionization time-of-flight (SELDI-TOF) proteomic data. The proposed two-step Bayes classification framework was equal to and, in some cases, outperformed other classification methods in terms of prediction accuracy, minimum number of classification markers, and computational time.
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NASA Astrophysics Data System (ADS)
Miller, Stephanie A.; Shank, G. Christopher
2013-01-01
We investigated chromophoric dissolved organic matter (CDOM) dynamics in response to the severe drought conditions of 2009 in the Aransas-Copano (AC) Bay complex and adjacent nearshore Gulf of Mexico (GoM) along the southern Texas (USA) coast. Surface water absorption coefficients (a305 in m-1) were measured daily at the University of Texas at Austin Marine Science Institute (UTMSI) pier located at the interface between the AC complex and the GoM. From June to August 2009, a305 averaged 0.81 ± 0.31 m-1 compared to 1.20 ± 0.70 m-1 during summer of 2008 (June-August) and 1.84 ± 0.34 m-1 during summer 2007 (non-drought year). Despite negligible freshwater input to the AC system for most of 2009, mean a305 values for AC Bay sites were similar in 2008 and 2009, ranging from 3.24 ± 0.60 m-1 in the lower estuary to 6.22 ± 0.55 m-1 in the upper estuary during summer 2009, and 3.15 ± 0.38 m-1 to 6.81 ± 0.73 m-1 during summer 2008 (no data for 2007). CDOM photobleaching experiments were performed using a SunTest XLS + solar simulator with an irradiation spectrum that closely matches solar UV at subtropical latitudes. AC Bay samples exhibited a305 photobleaching half-lives of 33-48 h, while GoM samples exhibited a305 photobleaching half-lives of 36-89 h. We estimate that summertime photobleaching may reduce CDOM levels by >50% in the AC bay complex before discharge into the GoM and by up to 25% more throughout the nearshore waters along the western GoM shelf.
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Photocopy of drawing. LAUNCH COMPLEX 39. NASA John F. Kennedy ...
Photocopy of drawing. LAUNCH COMPLEX 39. NASA John F. Kennedy Space Center, Florida. File Number 203-100, Urbahn-Roberts-Seelye-Moran, October 1963. VERTICAL ASSEMBLY BUILDING, LOW BAY, SECTIONS J-J, K-K, & L-L. Sheet 33-32 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL
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Multiscale Reduced Order Modeling of Complex Multi-Bay Structures
2013-07-01
overall sound pressure level (OASPL) was 144dB and a series of 200 “snapshots” were obtained from the stationary part of the MSC /Nastran SOL 400... MSC /Nastran SOL 400, the power spectral densities computed, and their mean used for validation of the 85-mode ROM. The ROM results were obtained using...middle point of bay 5 as a function of frequency, MSC /Nastran SOL 400 and NX/Nastran SOL601. ...................... 68 4.44. Transverse displacement
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ERIC Educational Resources Information Center
Alameda County School Dept., Hayward, CA.
Project MER (Marine Ecology Research) is aimed at improving environmental education in the San Francisco Bay Area schools. As part of meeting this goal, it is hoped that students and teachers can see the results of their efforts being put to practical use. This guide is the fourth of a series which was produced to help students and teachers gather…
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ERIC Educational Resources Information Center
Kimsey, J. B.; Fisk, Leonard O.
1960-01-01
This key to freshwater and anadromous fishes of California is included as the fifth of a series of guides being produced by Project MER (Marine Ecology Research). This project is part of the effort to improve environmental education in the San Francisco Bay Area schools by gathering and organizing data on the ecological character of the San…
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Mobile Bay river plume mixing in the inner shelf
NASA Astrophysics Data System (ADS)
Parra, S. M.; Book, J. W.; Warner, S. J.; Moum, J.
2017-12-01
The microtidal region (0.5 m spring tides) of the inner shelf outside Mobile Bay presented a complex circulation pattern driven by the pulsed river discharge and winds. Currents, salinity, temperature, and turbulence profiles were measured for up to three weeks in April 2016 at six moorings outside Mobile Bay. Currents varied between locations and with depth. During neap and spring tides the currents were reliably >0.4 and <0.4 m/s, respectively. The outflow from Mobile Bay generated a complex density circulation, where two to three layers were normally present. Multiple density layers included a thicker brackish middle layer (5-10 m thickness), and a salty bottom layer (5-10 m thickness), with a thin ( 1-3 m) freshwater surface layer found intermittently. The multilayer currents were strongest at neap tides (>0.5 m/s) and toward deeper waters, concurrent with the strongest stratification. The possible flow drivers considered include tides, winds, inertial oscillations, waves, and stratification. Turbulent kinetic energy production and dissipation were calculated with multiple methods using data from bottom-mounted, upward-looking acoustic Doppler current profilers sampling at 1 Hz, and using data from line-moored chi-pod turbulent temperature microstructure instruments sampling at 100 Hz. This work explores different forcing mechanisms involved in modulating the circulation and turbulence in a multi-layered pulsed-river inner shelf region in the Gulf of Mexico.
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O'Neill, Andrea; Erikson, Li; Barnard, Patrick
2017-01-01
While global climate models (GCMs) provide useful projections of near-surface wind vectors into the 21st century, resolution is not sufficient enough for use in regional wave modeling. Statistically downscaled GCM projections from Multivariate Adaptive Constructed Analogues provide daily averaged near-surface winds at an appropriate spatial resolution for wave modeling within the orographically complex region of San Francisco Bay, but greater resolution in time is needed to capture the peak of storm events. Short-duration high wind speeds, on the order of hours, are usually excluded in statistically downscaled climate models and are of key importance in wave and subsequent coastal flood modeling. Here we present a temporal downscaling approach, similar to constructed analogues, for near-surface winds suitable for use in local wave models and evaluate changes in wind and wave conditions for the 21st century. Reconstructed hindcast winds (1975–2004) recreate important extreme wind values within San Francisco Bay. A computationally efficient method for simulating wave heights over long time periods was used to screen for extreme events. Wave hindcasts show resultant maximum wave heights of 2.2 m possible within the Bay. Changes in extreme over-water wind speeds suggest contrasting trends within the different regions of San Francisco Bay, but 21th century projections show little change in the overall magnitude of extreme winds and locally generated waves.
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Höhna, Sebastian; Landis, Michael J.
2016-01-01
Programs for Bayesian inference of phylogeny currently implement a unique and fixed suite of models. Consequently, users of these software packages are simultaneously forced to use a number of programs for a given study, while also lacking the freedom to explore models that have not been implemented by the developers of those programs. We developed a new open-source software package, RevBayes, to address these problems. RevBayes is entirely based on probabilistic graphical models, a powerful generic framework for specifying and analyzing statistical models. Phylogenetic-graphical models can be specified interactively in RevBayes, piece by piece, using a new succinct and intuitive language called Rev. Rev is similar to the R language and the BUGS model-specification language, and should be easy to learn for most users. The strength of RevBayes is the simplicity with which one can design, specify, and implement new and complex models. Fortunately, this tremendous flexibility does not come at the cost of slower computation; as we demonstrate, RevBayes outperforms competing software for several standard analyses. Compared with other programs, RevBayes has fewer black-box elements. Users need to explicitly specify each part of the model and analysis. Although this explicitness may initially be unfamiliar, we are convinced that this transparency will improve understanding of phylogenetic models in our field. Moreover, it will motivate the search for improvements to existing methods by brazenly exposing the model choices that we make to critical scrutiny. RevBayes is freely available at http://www.RevBayes.com. [Bayesian inference; Graphical models; MCMC; statistical phylogenetics.] PMID:27235697
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Numerical modeling of salt marsh morphological change induced by Hurricane Sandy
Hu, Kelin; Chen, Qin; Wang, Hongqing; Hartig, Ellen K.; Orton, Philip M.
2018-01-01
The salt marshes of Jamaica Bay serve as a recreational outlet for New York City residents, mitigate wave impacts during coastal storms, and provide habitat for critical wildlife species. Hurricanes have been recognized as one of the critical drivers of coastal wetland morphology due to their effects on hydrodynamics and sediment transport, deposition, and erosion processes. In this study, the Delft3D modeling suite was utilized to examine the effects of Hurricane Sandy (2012) on salt marsh morphology in Jamaica Bay. Observed marsh elevation change and accretion from rod Surface Elevation Tables and feldspar Marker Horizons (SET-MH) and hydrodynamic measurements during Hurricane Sandy were used to calibrate and validate the wind-waves-surge-sediment transport-morphology coupled model. The model results agreed well with in situ field measurements. The validated model was then used to detect salt marsh morphological change due to Sandy across Jamaica Bay. Model results indicate that the island-wide morphological changes in the bay's salt marshes due to Sandy were in the range of −30 mm (erosion) to +15 mm (deposition), and spatially complex and heterogeneous. The storm generated paired deposition and erosion patches at local scales. Salt marshes inside the west section of the bay showed erosion overall while marshes inside the east section showed deposition from Sandy. The net sediment amount that Sandy brought into the bay is only about 1% of the total amount of reworked sediment within the bay during the storm. Numerical experiments show that waves and vegetation played a critical role in sediment transport and associated wetland morphological change in Jamaica Bay. Furthermore, without the protection of vegetation, the marsh islands of Jamaica Bay would experience both more erosion and less accretion in coastal storms.
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Höhna, Sebastian; Landis, Michael J; Heath, Tracy A; Boussau, Bastien; Lartillot, Nicolas; Moore, Brian R; Huelsenbeck, John P; Ronquist, Fredrik
2016-07-01
Programs for Bayesian inference of phylogeny currently implement a unique and fixed suite of models. Consequently, users of these software packages are simultaneously forced to use a number of programs for a given study, while also lacking the freedom to explore models that have not been implemented by the developers of those programs. We developed a new open-source software package, RevBayes, to address these problems. RevBayes is entirely based on probabilistic graphical models, a powerful generic framework for specifying and analyzing statistical models. Phylogenetic-graphical models can be specified interactively in RevBayes, piece by piece, using a new succinct and intuitive language called Rev. Rev is similar to the R language and the BUGS model-specification language, and should be easy to learn for most users. The strength of RevBayes is the simplicity with which one can design, specify, and implement new and complex models. Fortunately, this tremendous flexibility does not come at the cost of slower computation; as we demonstrate, RevBayes outperforms competing software for several standard analyses. Compared with other programs, RevBayes has fewer black-box elements. Users need to explicitly specify each part of the model and analysis. Although this explicitness may initially be unfamiliar, we are convinced that this transparency will improve understanding of phylogenetic models in our field. Moreover, it will motivate the search for improvements to existing methods by brazenly exposing the model choices that we make to critical scrutiny. RevBayes is freely available at http://www.RevBayes.com [Bayesian inference; Graphical models; MCMC; statistical phylogenetics.]. © The Author(s) 2016. Published by Oxford University Press, on behalf of the Society of Systematic Biologists.
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Sediment transport in the San Francisco Bay Coastal System: An overview
Barnard, Patrick L.; Schoellhamer, David H.; Jaffe, Bruce E.; Lester J. McKee,
2013-01-01
The papers in this special issue feature state-of-the-art approaches to understanding the physical processes related to sediment transport and geomorphology of complex coastal-estuarine systems. Here we focus on the San Francisco Bay Coastal System, extending from the lower San Joaquin-Sacramento Delta, through the Bay, and along the adjacent outer Pacific Coast. San Francisco Bay is an urbanized estuary that is impacted by numerous anthropogenic activities common to many large estuaries, including a mining legacy, channel dredging, aggregate mining, reservoirs, freshwater diversion, watershed modifications, urban run-off, ship traffic, exotic species introductions, land reclamation, and wetland restoration. The Golden Gate strait is the sole inlet connecting the Bay to the Pacific Ocean, and serves as the conduit for a tidal flow of ~ 8 x 109 m3/day, in addition to the transport of mud, sand, biogenic material, nutrients, and pollutants. Despite this physical, biological and chemical connection, resource management and prior research have often treated the Delta, Bay and adjacent ocean as separate entities, compartmentalized by artificial geographic or political boundaries. The body of work herein presents a comprehensive analysis of system-wide behavior, extending a rich heritage of sediment transport research that dates back to the groundbreaking hydraulic mining-impact research of G.K. Gilbert in the early 20th century.
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Spectroscopic study of trivalent praseodymium in barium yttrium fluoride
NASA Astrophysics Data System (ADS)
Bowlby, Brian Edward
1998-09-01
This work investigates the spectroscopic properties of trivalent praseodymium (Pr3+) in barium yttrium fluoride (BaY2F8). Two doping concentrations were studied: BaY2F8:Pr3+ (.3%) and BaY2F8:Pr3+ (1%). Absorption spectra were taken at 77K and 300K and these were then used to calculate the Judd-Ofelt coefficients for both samples. These coefficients were then used to calculate the theoretical lifetimes and radiative branching ratios for all manifolds. Continuous luminescence spectra and lifetime measurements were also performed, and from these, experimentally determined values for the branching ratio and lifetimes were determined. These were then compared to their theoretical counterparts. It was found that while the theory gave values that were qualitatively correct, the quantitative correlation between theory and experiment shows the complexity of the physical reality and the difficulty of synthesizing an encompassing theoretical model. Absorption spectra and continuous luminescence spectra were also used to determine the energy levels of all manifolds in both samples. A total of 59 energy levels in 11 manifolds were identified in the BaY2F8:Pr3+ (1%) sample, while 51 levels in 11 manifolds were identified in the BaY2F8:Pr3+ (.3%) sample. Finally, the effects of temperature on the line width and line position for several radiative transitions was studied. It was found that while most transitions exhibited the expected broadening and shifting towards longer wavelengths at higher temperatures (a 'red shift'), the transition from the 3P0 level to the 3H4 ground state showed a shift towards shorter wavelengths at higher temperature (a 'blue shift'). Again this highlights the complexity of the ion- host interaction.
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Ruvindy, Rendy; White III, Richard Allen; Neilan, Brett Anthony; Burns, Brendan Paul
2016-01-01
Modern microbial mats are potential analogues of some of Earth's earliest ecosystems. Excellent examples can be found in Shark Bay, Australia, with mats of various morphologies. To further our understanding of the functional genetic potential of these complex microbial ecosystems, we conducted for the first time shotgun metagenomic analyses. We assembled metagenomic next-generation sequencing data to classify the taxonomic and metabolic potential across diverse morphologies of marine mats in Shark Bay. The microbial community across taxonomic classifications using protein-coding and small subunit rRNA genes directly extracted from the metagenomes suggests that three phyla Proteobacteria, Cyanobacteria and Bacteriodetes dominate all marine mats. However, the microbial community structure between Shark Bay and Highbourne Cay (Bahamas) marine systems appears to be distinct from each other. The metabolic potential (based on SEED subsystem classifications) of the Shark Bay and Highbourne Cay microbial communities were also distinct. Shark Bay metagenomes have a metabolic pathway profile consisting of both heterotrophic and photosynthetic pathways, whereas Highbourne Cay appears to be dominated almost exclusively by photosynthetic pathways. Alternative non-rubisco-based carbon metabolism including reductive TCA cycle and 3-hydroxypropionate/4-hydroxybutyrate pathways is highly represented in Shark Bay metagenomes while not represented in Highbourne Cay microbial mats or any other mat forming ecosystems investigated to date. Potentially novel aspects of nitrogen cycling were also observed, as well as putative heavy metal cycling (arsenic, mercury, copper and cadmium). Finally, archaea are highly represented in Shark Bay and may have critical roles in overall ecosystem function in these modern microbial mats. PMID:26023869
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Stoker, Y.E.; Levesque, V.A.; Fritz, E.M.
1996-01-01
Nutrient enrichment in Tampa Bay has caused a decline in water quality in the estuary. Efforts to reduce the nutrient loading to Tampa Bay have resulted in improvement in water quality from 1981 to 1991. However, Tampa Bay still is onsidered enriched with nutrients. Water quality in East Bay (located at the northeastern part of Hillsborough Bay, which is an embayment in Tampa Bay) is not improving at the same rate as the rest of the bay. East Bay is the center of shipping activity in Tampa Bay and the seventh largest port in the United States. One of the primary cargoes is phosphate ore and related products such as fertilizer. The potential for nutrient loading to East Bay from shipping activities is high and has not previously been measured. Nitrogen and phosphorus loads from East Bay to Hillsborough Bay were measured during selected time periods during June 1992 through May 1993; these data were used to estimate seasonal and annual loads. These loads were evaluated to determine whether the loss of fertilizer products from shipping activities resulted in increased nutrient loading to Hillsborough Bay. Discharge was measured, and water-quality samples were collected at the head of East Bay (exiting McKay Bay), and at the mouth of East Bay. Discharge and nitrogen and phosphorus concentrations for the period June 1992 through May 1993 were used to compute loads. Discharges from McKay Bay, Delaney Creek, and East Bay are highly variable because of the effect of tide. Flow patterns during discharge measurements generally were unidirectional in McKay Bay and Delaney Creek, but more complex, bidirectional patterns were observed at the mouth of East Bay. Tidally affected discharge data were digitally filtered with the Godin filter to remove the effects of tide so that residual, or net, discharge could be determined. Daily mean discharge from McKay Bay ranged from -1,900 to 2,420 cubic feet per second; from Delaney Creek, -3.8 to 162 cubic feet per second; and from East Bay, -437 to 3,780 cubic feet per second. Water quality in McKay Bay, Delaney Creek, and East Bay varies vertically, areally, and seasonally. Specific conductance and concentrations of phosphorus and ammonia nitrogen were greater near the bottom than near the surface at the head and mouth of East Bay. Concentrations of total nitrogen and ammonia plus organic nitrogen generally were greater at the head of East Bay than at the mouth, indicating that McKay Bay is the primary source of nitrogen to East Bay. Concentrations of total ammonia nitrogen, nitrite plus nitrate nitrogen, phosphorus, orthophosphorus, and suspended solids and values of turbidity and specific conductance generally were greater at the mouth of East Bay than at the head. The greatest concentrations of nitrogen and phosphorus were measured in Delaney Creek. In East Bay and McKay Bay, the greatest concentrations of nitrogen, phosphorus, and ammonia plus organic nitrogen occurred in summer, whereas turbidity, specific conductance, and concentrations of suspended solids were greater in winter. The greatest daily mean loads from McKay Bay and East Bay occurred in late June 1992 and April and May 1993 and coincided with periods of daily mean discharge greater than about 2,000 cubic feet per second. Although concentrations of nitrogen and phosphorus were greater in Delaney Creek than in McKay Bay and East Bay, loads were minimal because of minimal discharges from Delaney Creek. Monthly loads of total nitrogen ranged from about 20 tons to about 83 tons at McKay Bay; from about 1 ton to 4.2 tons at Delaney Creek; and from about 17 tons to 76 tons at the mouth of East Bay. Monthly loads of phosphorus ranged from about 11 tons to about 45 tons at McKay Bay; from about 0.62 ton to 2.6 tons at Delaney Creek; and from about 10 tons to about 45 tons at the mouth of East Bay. The results of this study indicate that nitrogen and phosphorus loads from the basin draining directly to East Bay (excluding loads from the McKa
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ERIC Educational Resources Information Center
Alameda County School Dept., Hayward, CA.
Project MER (Marine Ecology Research) is aimed at improving environmental education in the San Francisco Bay Area schools. As part of meeting this goal, it is hoped that students and teachers can see the results of their efforts being put to practical use. This guide is the first of a series produced to help the students and teachers gather data…
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The Muon System of the Daya Bay Reactor Antineutrino Experiment
An, F. P.; Hackenburg, R. W.; Brown, R. E.; ...
2014-10-05
The Daya Bay experiment consists of functionally identical antineutrino detectors immersed in pools of ultrapure water in three well-separated underground experimental halls near two nuclear reactor complexes. These pools serve both as shields against natural, low-energy radiation, and as water Cherenkov detectors that efficiently detect cosmic muons using arrays of photomultiplier tubes. Each pool is covered by a plane of resistive plate chambers as an additional means of detecting muons. Design, construction, operation, and performance of these muon detectors are described. (auth)
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1976-09-01
the New York Harbor area and especially the Jamaica Bay complex was used to determine the effects of 13 different hurricane surge barrier plans on...vary directly with the total cross-sectional area of the naviga- tion opening and tidal openings. d. barrier plans B, C-l, C-2, and C-3 would have... plan C-1 with a conservative dye source seaward of the barrier indicated that average dye concentrations will be increased slightly in most areas in
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Integrating science and resource management in Tampa Bay, Florida
Yates, Kimberly K.; Greening, Holly; Morrison, Gerold
2011-01-01
Tampa Bay is recognized internationally for its remarkable progress towards recovery since it was pronounced "dead" in the late 1970s. Due to significant efforts by local governments, industries and private citizens throughout the watershed, water clarity in Tampa Bay is now equal to what it was in 1950, when population in the watershed was less than one-quarter of what it is today. Seagrass extent has increased by more than 8,000 acres since the mid-1980s, and fish and wildlife populations are increasing. Central to this successful turn-around has been the Tampa Bay resource management community's long-term commitment to development and implementation of strong science-based management strategies. Research institutions and agencies, including Eckerd College, the Florida Wildlife Commission Fish and Wildlife Research Institute, Mote Marine Laboratory, National Oceanic and Atmospheric Administration, the Southwest Florida Water Management District, University of South Florida, U.S. Environmental Protection Agency, U.S. Geological Survey, local and State governments, and private companies contribute significantly to the scientific basis of our understanding of Tampa Bay's structure and ecological function. Resource management agencies, including the Tampa Bay Regional Planning Council's Agency on Bay Management, the Southwest Florida Water Management District's Surface Water Improvement and Management Program, and the Tampa Bay Estuary Program, depend upon this scientific basis to develop and implement regional adaptive management programs. The importance of integrating science with management has become fully recognized by scientists and managers throughout the region, State and Nation. Scientific studies conducted in Tampa Bay over the past 10–15 years are increasingly diverse and complex, and resource management programs reflect our increased knowledge of geology, hydrology and hydrodynamics, ecology and restoration techniques. However, a synthesis of this research and its integration into resource management has not been prepared for Tampa Bay since the mid-1980s. The need for an up-to-date synthesis of Tampa Bay science and management has resulted in the production of this document. The U.S. Geological Survey recently completed a 5-year Tampa Bay Integrated Science Study, and the Tampa Bay Estuary Program updated the Comprehensive Conservation and Management Plan for Tampa Bay in 2006. These efforts build upon results of the many research and management studies and programs summarized here.
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Bay breeze influence on surface ozone at Edgewood, MD during July 2011.
Stauffer, Ryan M; Thompson, Anne M; Martins, Douglas K; Clark, Richard D; Goldberg, Daniel L; Loughner, Christopher P; Delgado, Ruben; Dickerson, Russell R; Stehr, Jeffrey W; Tzortziou, Maria A
Surface ozone (O 3 ) was analyzed to investigate the role of the bay breeze on air quality at two locations in Edgewood, Maryland (lat: 39.4°, lon: -76.3°) for the month of July 2011. Measurements were taken as part of the first year of NASA's "Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality" (DISCOVER-AQ) Earth Venture campaign and as part of NASA's Geostationary for Coastal and Air Pollution Events Chesapeake Bay Oceanographic campaign with DISCOVER-AQ (Geo-CAPE CBODAQ). Geo-CAPE CBODAQ complements DISCOVER-AQ by providing ship-based observations over the Chesapeake Bay. A major goal of DISCOVER-AQ is determining the relative roles of sources, photochemistry and local meteorology during air quality events in the Mid-Atlantic region of the U.S. Surface characteristics, transport and vertical structures of O 3 during bay breezes were identified using in-situ surface, balloon and aircraft data, along with remote sensing equipment. Localized late day peaks in O 3 were observed during bay breeze days, maximizing an average of 3 h later compared to days without bay breezes. Of the 10 days of July 2011 that violated the U.S. Environmental Protection Agency (EPA) 8 h O 3 standard of 75 parts per billion by volume (ppbv) at Edgewood, eight exhibited evidence of a bay breeze circulation. The results indicate that while bay breezes and the processes associated with them are not necessary to cause exceedances in this area, bay breezes exacerbate poor air quality that sustains into the late evening hours at Edgewood. The vertical and horizontal distributions of O 3 from the coastal Edgewood area to the bay also show large gradients that are often determined by boundary layer stability. Thus, developing air quality models that can sufficiently resolve these dynamics and associated chemistry, along with more consistent monitoring of O 3 and meteorology on and along the complex coastline of Chesapeake Bay must be a high priority.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Ruvindy, Rendy; White III, Richard Allen; Neilan, Brett Anthony
Modern microbial mats are potential analogues of some of Earth’s earliest ecosystems. Excellent examples can be found in Shark Bay, Australia, with mats of various morphologies. To further our understanding of the functional genetic potential of these complex microbial ecosystems, we conducted for the first time shotgun metagenomic analyses. We assembled metagenomic nextgeneration sequencing data to classify the taxonomic and metabolic potential across diverse morphologies of marine mats in Shark Bay. The microbial community across taxonomic classifications using protein-coding and small subunit rRNA genes directly extracted from the metagenomes suggests that three phyla Proteobacteria, Cyanobacteria and Bacteriodetes dominate all marinemore » mats. However, the microbial community structure between Shark Bay and Highbourne Cay (Bahamas) marine systems appears to be distinct from each other. The metabolic potential (based on SEED subsystem classifications) of the Shark Bay and Highbourne Cay microbial communities were also distinct. Shark Bay metagenomes have a metabolic pathway profile consisting of both heterotrophic and photosynthetic pathways, whereas Highbourne Cay appears to be dominated almost exclusively by photosynthetic pathways. Alternative non-rubisco-based carbon metabolism including reductive TCA cycle and 3-hydroxypropionate/4-hydroxybutyrate pathways is highly represented in Shark Bay metagenomes while not represented in Highbourne Cay microbial mats or any other mat forming ecosystems investigated to date. Potentially novel aspects of nitrogen cycling were also observed, as well as putative heavy metal cycling (arsenic, mercury, copper and cadmium). Finally, archaea are highly represented in Shark Bay and may have critical roles in overall ecosystem function in these modern microbial mats.« less
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Remote sensing of water quality and contaminants in the California Bay-Delta
NASA Astrophysics Data System (ADS)
Fichot, C. G.; Downing, B. D.; Windham-Myers, L.; Marvin-DiPasquale, M. C.; Bergamaschi, B. A.; Thompson, D. R.; Gierach, M. M.
2014-12-01
The California Bay-Delta is a highly altered ecosystem largely reclaimed from wetlands for agriculture, and millions of acres of farmland and Californians rely on the Bay-Delta for their water supply. The Bay-Delta also harbors important habitats for many organisms, including commercial and endangered species. Recently, the Delta Stewardship Council developed a two component mission (coequal goals) to 1) provide a more reliable water supply for California while 2) protecting, restoring, and enhancing the Bay-Delta ecosystem. Dissolved organic carbon, turbidity, and contaminants such as methylmercury represent important water quality issues for water management and in the context of wetland restoration in the Bay-Delta, and can threaten the achievement of the coequal goals. Here, we use field measurements of optical properties, chemical analyses, and remotely sensed data acquired with the airborne Portable Remote Imaging SpectroMeter (PRISM ; http://prism.jpl.nasa.gov/index.html) to demonstrate these water quality parameters and the study of their dynamics in the Bay-Delta are amenable to remote sensing. PRISM provides high signal-to-noise, high spatial resolution (~2 m), hyperspectral measurements of remote-sensing reflectance in the 350-1050 nm range, and therefore has the adequate resolutions for water quality monitoring in inland, optically complex waters. Remote sensing of water quality will represent a valuable complement to existing in situ water quality monitoring programs in this region and will help with decision-making to achieve the co-equal goals.
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Local diurnal wind-driven variabiity and upwelling in a small coastal embayment
NASA Astrophysics Data System (ADS)
Walter, R. K.; Reid, E. C.; Davis, K. A.; Armenta, K. J.; Merhoff, K.; Nidzieko, N.
2017-12-01
The oceanic response to high-frequency local diurnal wind forcing is examined in a small coastal embayment located along an understudied stretch of the central California coast. We show that local diurnal wind forcing is the dominant control on nearshore temperature variability and circulation patterns. A complex empirical orthogonal function (CEOF) analysis of velocities in San Luis Obispo Bay reveals that the first-mode CEOF amplitude time series, which accounts for 47.9% of the variance, is significantly coherent with the local wind signal at the diurnal frequency and aligns with periods of weak and strong wind forcing. The diurnal evolution of the hydrographic structure and circulation in the bay is examined using both individual events and composite-day averages. During the late afternoon, the local wind strengthens and results in a sheared flow with near-surface warm waters directed out of the bay and a compensating flow of colder waters into the bay over the bottom portion of the water column. This cold water intrusion into the bay causes isotherms to shoal toward the surface and delivers subthermocline waters to shallow reaches of the bay, representing a mechanism for small-scale upwelling. When the local winds relax, the warm water mass advects back into the bay in the form of a buoyant plume front. Local diurnal winds are expected to play an important role in nearshore dynamics and local upwelling in other small coastal embayments with important implications for various biological and ecological processes.
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Local diurnal wind-driven variability and upwelling in a small coastal embayment
NASA Astrophysics Data System (ADS)
Walter, Ryan K.; Reid, Emma C.; Davis, Kristen A.; Armenta, Kevin J.; Merhoff, Kevin; Nidzieko, Nicholas J.
2017-02-01
The oceanic response to high-frequency local diurnal wind forcing is examined in a small coastal embayment located along an understudied stretch of the central California coast. We show that local diurnal wind forcing is the dominant control on nearshore temperature variability and circulation patterns. A complex empirical orthogonal function (CEOF) analysis of velocities in San Luis Obispo Bay reveals that the first-mode CEOF amplitude time series, which accounts for 47.9% of the variance, is significantly coherent with the local wind signal at the diurnal frequency and aligns with periods of weak and strong wind forcing. The diurnal evolution of the hydrographic structure and circulation in the bay is examined using both individual events and composite-day averages. During the late afternoon, the local wind strengthens and results in a sheared flow with near-surface warm waters directed out of the bay and a compensating flow of colder waters into the bay over the bottom portion of the water column. This cold water intrusion into the bay causes isotherms to shoal toward the surface and delivers subthermocline waters to shallow reaches of the bay, representing a mechanism for small-scale upwelling. When the local winds relax, the warm water mass advects back into the bay in the form of a buoyant plume front. Local diurnal winds are expected to play an important role in nearshore dynamics and local upwelling in other small coastal embayments with important implications for various biological and ecological processes.
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Hostettler, F.D.; Pereira, W.E.; Kvenvolden, K.A.; VanGeen, A.; Luoma, S.N.; Fuller, C.C.; Anima, R.
1999-01-01
San Francisco Bay is one of the world's largest urbanized estuarine systems. Its water and sediment receive organic input from a wide variety of sources; much of this organic material is anthropogenically derived. To document the spatial and historical record of the organic contaminant input, surficial sediment from 17 sites throughout San Francisco Bay and sediment cores from two locations Richardson Bay and San Pablo Bay were analyzed for biomarker constituents. Biomarkers, that is, 'molecular fossils', primarily hopanes, steranes, and n-alkanes, provide information on anthropogenic contamination, especially that related to petrogenic sources, as well as on recent input of biogenic material. The biomarker parameters from the surficial sediment and the upper horizons of the cores show a dominance of anthropogenic input, whereas the biomarker profiles at the lower horizons of the cores indicate primarily biogenic input. In the Richardson Bay core the gradual upcore transition from lower maturity background organics to a dominance of anthropogenic contamination occurred about 70-100 years ago and corresponds to the industrial development of the San Francisco Bay area. In San Pablo Bay, the transition was very abrupt, reflecting the complex depositional history of the area. This sharp transition, perhaps indicating a depositional hiatus or erosional period, dated at pre-1952, is clearly visible. Below, the hiatus the biomarker parameters are immature; above, they are mature and show an anthropogenic overlay. Higher concentrations of terrigenous n-alkanes in the upper horizons in this core are indicative of an increase in terrigenous organic matter input in San Pablo Bay, possibly a result of water diversion projects and changes in the fresh water flow into the Bay from the Delta. Alternatively, it could reflect a dilution of organic material in the lower core sections with hydraulic mining debris.
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Jaffe, B.E.; Smith, R.E.; Foxgrover, A.C.
2007-01-01
Analysis of a series of historical bathymetric surveys has revealed large changes in morphology and sedimentation from 1856 to 1983 in San Pablo Bay, California. In 1856, the morphology of the bay was complex, with a broad main channel, a major side channel connecting to the Petaluma River, and an ebb-tidal delta crossing shallow parts of the bay. In 1983, its morphology was simpler because all channels except the main channel had filled with sediment and erosion had planed the shallows creating a uniform gently sloping surface. The timing and patterns of geomorphic change and deposition and erosion of sediment were influenced by human activities that altered sediment delivery from rivers. From 1856 to 1887, high sediment delivery (14.1 ?? 106 m3/yr) to San Francisco Bay during the hydraulic gold-mining period in the Sierra Nevada resulted in net deposition of 259 ?? 14 ?? 106 m3 in San Pablo Bay. This rapid deposition filled channels and increased intertidal mudflat area by 60% (37.4 ?? 3.4 to 60.6 ?? 6.2 km2). From 1951 to 1983, 23 ?? 3 ?? 106 m3 of sediment was eroded from San Pablo Bay as sediment delivery from the Sacramento and San Joaquin Rivers decreased to 2.8 ?? 106 m3/yr because of damming of rivers, riverbank protection, and altered land use. Intertidal mudflat area in 1983 was 31.8 ?? 3.9 km2, similar to that in 1856. Intertidal mudflat distribution in 1983, however, was fairly uniform whereas most of the intertidal mudflats were in the western part of San Pablo Bay in 1856. Sediment delivery, through its affect on shallow parts of the bay, was determined to be a primary control on intertidal mudflat area. San Pablo Bay has been greatly affected by human activities and will likely continue to erode in the near term in response to a diminished sediment delivery from rivers. ?? 2007 Elsevier Ltd. All rights reserved.
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As ecological risk assessments (ERA) move beyond organism-based determinations towards probabilistic population-level assessments, model complexity must be evaluated against the goals of the assessment, the information available to parameterize components with minimal dependence ...
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Narale, Dhiraj Dhondiram; Anil, Arga Chandrashekar
2017-02-15
Dinoflagellate community structure from two semi-enclosed areas along the South Andaman region, India, was investigated to assess the anthropogenic impact on coastal water quality. At the densely inhabited Port Blair Bay, the dominance of mixotrophs in water and Protoperidinoids in sediments was attributed to anthropogenic nutrient enrichment and prey availability. A significant decrease in dinoflagellate abundance from inner to outer bay emphasize the variation in nutrient availability. The dominance of autotrophs and Gonyaulacoid cysts at the North Bay highlight low nutrient conditions with less anthropogenic pressure. The occurrence of oceanic Ornithocercus steinii and Diplopsalis sp. could evince the oceanic water intrusion into the North Bay. Nine potentially harmful and red-tide-forming species including Alexandrium tamarense complex, A. minutum were identified in this study. Although there are no harmful algal bloom (HABs) incidences in this region so far, increasing coastal pollution could support their candidature towards the future HABs initiation and development. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Kim, Tae-Wook; Kim, Dongseon; Baek, Seung Ho; Kim, Young Ok
2015-01-15
The successful management of sustainable coastal environments that are beneficial to both humans and marine ecosystems requires knowledge about factors that are harmful to such environments. Here, we investigated seawater nutrient and carbon parameters between 2010 and 2012 in Kwangyang Bay, Korea, a coastal environment that has been exposed to intensive anthropogenic activities. The data were analyzed using cluster and factor analysis. We found that the biogeochemical cycles of nutrients and carbon were determined by river discharge into the bay and biological activity. However, the impacts of these factors varied both spatially and seasonally. During the past 10 years, nutrient loads from the river and industrial complexes to the bay have decreased. The impacts of this decrease are visible in the phosphate concentration, which has fallen to a third of its initial value. We also examined the potential role of atmospheric nitrogen deposition in nitrogen cycling in the study area. Copyright © 2014 Elsevier Ltd. All rights reserved.
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An Intrathermocline Eddy and a tropical cyclone in the Bay of Bengal
NASA Astrophysics Data System (ADS)
Gordon, Arnold L.; Shroyer, Emily; Murty, V. S. N.
2017-04-01
The Bay of Bengal, subjected to monsoonal forcing and tropical cyclones, displays a complex field of ocean eddies. On 5 December 2013 a sub-surface vortex or Intrathermocline Eddy (ITE) composed of water characteristic of the Andaman Sea was observed within the thermocline of the western Bay of Bengal. We propose that the ITE was the product of Tropical Cyclone Lehar interaction on 27 November 2013 with a westward propagating surface eddy from the eastern Bay of Bengal. While Lehar’s interaction with the ocean initially removes heat from the upper layers of the eddy, air-sea flux is limited as the deeper portions of the eddy was subducted into the stratified thermocline, inhibiting further interaction with the atmosphere. The ITE core from 30 to 150 m is thus isolated from local air-sea fluxes by strong stratification at the mixed layer base, and its periphery is stable to shear instability, suggestive of longevity and the ability to carry water far distances with minimal modification.
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An Intrathermocline Eddy and a tropical cyclone in the Bay of Bengal.
Gordon, Arnold L; Shroyer, Emily; Murty, V S N
2017-04-12
The Bay of Bengal, subjected to monsoonal forcing and tropical cyclones, displays a complex field of ocean eddies. On 5 December 2013 a sub-surface vortex or Intrathermocline Eddy (ITE) composed of water characteristic of the Andaman Sea was observed within the thermocline of the western Bay of Bengal. We propose that the ITE was the product of Tropical Cyclone Lehar interaction on 27 November 2013 with a westward propagating surface eddy from the eastern Bay of Bengal. While Lehar's interaction with the ocean initially removes heat from the upper layers of the eddy, air-sea flux is limited as the deeper portions of the eddy was subducted into the stratified thermocline, inhibiting further interaction with the atmosphere. The ITE core from 30 to 150 m is thus isolated from local air-sea fluxes by strong stratification at the mixed layer base, and its periphery is stable to shear instability, suggestive of longevity and the ability to carry water far distances with minimal modification.
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An Intrathermocline Eddy and a tropical cyclone in the Bay of Bengal
Gordon, Arnold L.; Shroyer, Emily; Murty, V. S. N.
2017-01-01
The Bay of Bengal, subjected to monsoonal forcing and tropical cyclones, displays a complex field of ocean eddies. On 5 December 2013 a sub-surface vortex or Intrathermocline Eddy (ITE) composed of water characteristic of the Andaman Sea was observed within the thermocline of the western Bay of Bengal. We propose that the ITE was the product of Tropical Cyclone Lehar interaction on 27 November 2013 with a westward propagating surface eddy from the eastern Bay of Bengal. While Lehar’s interaction with the ocean initially removes heat from the upper layers of the eddy, air-sea flux is limited as the deeper portions of the eddy was subducted into the stratified thermocline, inhibiting further interaction with the atmosphere. The ITE core from 30 to 150 m is thus isolated from local air-sea fluxes by strong stratification at the mixed layer base, and its periphery is stable to shear instability, suggestive of longevity and the ability to carry water far distances with minimal modification. PMID:28401909
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Near bottom velocity and suspended solids measurements in San Francisco Bay, California
Gartner, Jeffrey W.; Cheng, Ralph T.; Cacchione, David A.; Tate, George B.
1997-01-01
Ability to accurately measure long-term time-series of turbulent mean velocity distribution within the bottom boundary layer (BBL) in addition to suspended solids concentration (SSC) is critical to understanding complex processes controlling transport, resuspension, and deposition of suspended sediments in bays and estuaries. A suite of instruments, including broad band acoustic Doppler current profilers (BB-ADCPs), capable of making very high resolution measurement of velocity profiles in the BBL, was deployed in the shipping channel of South San Francisco Bay (South Bay), California in an investigation of sediment dynamics during March and April 1995. Results of field measurements provide information to calculate suspended solids flux (SSF) at the site. Calculations show striking patterns; residual SSF varies through the spring-neap tidal cycle. Significant differences from one spring tide to another are caused by differences in tidal current diurnal inequalities. Winds from significant storms establish residual circulation patterns that may affect magnitude of residual SSF more than increased tidal energy at spring tides.
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Classifying emotion in Twitter using Bayesian network
NASA Astrophysics Data System (ADS)
Surya Asriadie, Muhammad; Syahrul Mubarok, Mohamad; Adiwijaya
2018-03-01
Language is used to express not only facts, but also emotions. Emotions are noticeable from behavior up to the social media statuses written by a person. Analysis of emotions in a text is done in a variety of media such as Twitter. This paper studies classification of emotions on twitter using Bayesian network because of its ability to model uncertainty and relationships between features. The result is two models based on Bayesian network which are Full Bayesian Network (FBN) and Bayesian Network with Mood Indicator (BNM). FBN is a massive Bayesian network where each word is treated as a node. The study shows the method used to train FBN is not very effective to create the best model and performs worse compared to Naive Bayes. F1-score for FBN is 53.71%, while for Naive Bayes is 54.07%. BNM is proposed as an alternative method which is based on the improvement of Multinomial Naive Bayes and has much lower computational complexity compared to FBN. Even though it’s not better compared to FBN, the resulting model successfully improves the performance of Multinomial Naive Bayes. F1-Score for Multinomial Naive Bayes model is 51.49%, while for BNM is 52.14%.
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NASA Astrophysics Data System (ADS)
Bratton, John F.; Colman, Steven M.; Thieler, E. Robert; Seal, Robert R.
2002-12-01
Two major pulses of sea-level rise are thought to have taken place since the last glacial maximum — meltwater pulses (mwp) 1A (12 cal ka) and 1B (9.5 cal ka). Between mwp 1B and about 6 cal ka, many of the complex coastal ecosystems which ring the world's oceans began to form. Here we report data for rhenium, carbon isotopes, total organic carbon, and fossil oysters from Chesapeake Bay which span the transition from fresh to brackish water conditions in the bay in the mid-Holocene. These data constrain sea-level change and resulting environmental change in the bay. They indicate that the transition was rapid, and that it was produced by (1) a third pulse of rapid eustatic sea-level rise, or (2) a geometry of the prehistoric Chesapeake Bay basin which predisposed it to a nonlinear response to a steadily rising sea level. Similar nonlinear changes in vulnerable coastal environments are likely to take place in the future due to polar warming, regardless of the timing or rate of sea-level rise.
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Bratton, John F.; Colman, Steven M.; Thieler, E. Robert; Seal, Robert R.
2003-01-01
Two major pulses of sea-level rise are thought to have taken place since the last glacial maximum — meltwater pulses (mwp) 1A (12 cal ka) and 1B (9.5 cal ka). Between mwp 1B and about 6 cal ka, many of the complex coastal ecosystems which ring the world’s oceans began to form. Here we report data for rhenium, carbon isotopes, total organic carbon, and fossil oysters from Chesapeake Bay which span the transition from fresh to brackish water conditions in the bay in the mid-Holocene. These data constrain sea-level change and resulting environmental change in the bay. They indicate that the transition was rapid, and that it was produced by (1) a third pulse of rapid eustatic sea-level rise, or (2) a geometry of the prehistoric Chesapeake Bay basin which predisposed it to a nonlinear response to a steadily rising sea level. Similar nonlinear changes in vulnerable coastal environments are likely to take place in the future due to polar warming, regardless of the timing or rate of sea-level rise.
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An experimental validation of genomic selection in octoploid strawberry
Gezan, Salvador A; Osorio, Luis F; Verma, Sujeet; Whitaker, Vance M
2017-01-01
The primary goal of genomic selection is to increase genetic gains for complex traits by predicting performance of individuals for which phenotypic data are not available. The objective of this study was to experimentally evaluate the potential of genomic selection in strawberry breeding and to define a strategy for its implementation. Four clonally replicated field trials, two in each of 2 years comprised of a total of 1628 individuals, were established in 2013–2014 and 2014–2015. Five complex yield and fruit quality traits with moderate to low heritability were assessed in each trial. High-density genotyping was performed with the Affymetrix Axiom IStraw90 single-nucleotide polymorphism array, and 17 479 polymorphic markers were chosen for analysis. Several methods were compared, including Genomic BLUP, Bayes B, Bayes C, Bayesian LASSO Regression, Bayesian Ridge Regression and Reproducing Kernel Hilbert Spaces. Cross-validation within training populations resulted in higher values than for true validations across trials. For true validations, Bayes B gave the highest predictive abilities on average and also the highest selection efficiencies, particularly for yield traits that were the lowest heritability traits. Selection efficiencies using Bayes B for parent selection ranged from 74% for average fruit weight to 34% for early marketable yield. A breeding strategy is proposed in which advanced selection trials are utilized as training populations and in which genomic selection can reduce the breeding cycle from 3 to 2 years for a subset of untested parents based on their predicted genomic breeding values. PMID:28090334
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Urbina, Angel; Mahadevan, Sankaran; Paez, Thomas L.
2012-03-01
Here, performance assessment of complex systems is ideally accomplished through system-level testing, but because they are expensive, such tests are seldom performed. On the other hand, for economic reasons, data from tests on individual components that are parts of complex systems are more readily available. The lack of system-level data leads to a need to build computational models of systems and use them for performance prediction in lieu of experiments. Because their complexity, models are sometimes built in a hierarchical manner, starting with simple components, progressing to collections of components, and finally, to the full system. Quantification of uncertainty inmore » the predicted response of a system model is required in order to establish confidence in the representation of actual system behavior. This paper proposes a framework for the complex, but very practical problem of quantification of uncertainty in system-level model predictions. It is based on Bayes networks and uses the available data at multiple levels of complexity (i.e., components, subsystem, etc.). Because epistemic sources of uncertainty were shown to be secondary, in this application, aleatoric only uncertainty is included in the present uncertainty quantification. An example showing application of the techniques to uncertainty quantification of measures of response of a real, complex aerospace system is included.« less
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Silva, Rita R.; Chrobot, Nina; Newman, Eryn; Schwarz, Norbert; Topolinski, Sascha
2017-01-01
Can the mere name of a seller determine his trustworthiness in the eye of the consumer? In 10 studies (total N = 608) we explored username complexity and trustworthiness of eBay seller profiles. Name complexity was manipulated through variations in username pronounceability and length. These dimensions had strong, independent effects on trustworthiness, with sellers with easy-to-pronounce or short usernames being rated as more trustworthy than sellers with difficult-to-pronounce or long usernames, respectively. Both effects were repeatedly found even when objective information about seller reputation was available. We hypothesized the effect of name complexity on trustworthiness to be based on the experience of high vs. low processing fluency, with little awareness of the underlying process. Supporting this, participants could not correct for the impact of username complexity when explicitly asked to do so. Three alternative explanations based on attributions of the variations in name complexity to seller origin (ingroup vs. outgroup), username generation method (seller personal choice vs. computer algorithm) and age of the eBay profiles (10 years vs. 1 year) were tested and ruled out. Finally, we show that manipulating the ease of reading product descriptions instead of the sellers’ names also impacts the trust ascribed to the sellers. PMID:29312062
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Estimation of Freshwater Flow to Joe Bay, South Florida.
NASA Astrophysics Data System (ADS)
Zucker, M. A.; Hittle, C. D.
2002-05-01
During the last century, drainage canals were constructed as part of the Central and Southern Flood Control (C&SF) project. Flood control was achieved but degradation to the Everglades ecosystem was evident. Problems related to Florida Bay include sea grass die off, algae blooms, and extreme salinity conditions. Modifications to the C&SF project are proposed as part of the Comprehensive Everglades Restoration Plan (CERP). One objective of CERP is to improve the timing and distribution of freshwater flow within the Everglades ecosystem and to Florida Bay. Several CERP projects propose changes to the existing canal network that borders Everglades National Park (ENP) in southern Miami-Dade County. An examination of flows to Joe Bay, a small embayment on the northeastern shores of Florida Bay, has provided baseline information on current spatial and temporal water deliveries prior to CERP modifications. Understanding the existing complex water delivery system and the effects the system has on Everglades hydrology will provide a necessary benchmark against which to measure restoration success. The study was initiated by the U.S. Geological Survey (USGS) in May 1999 to estimate creek flows to Joe Bay and determine the relative amounts derived from Taylor Slough and overflow from the C-111 Canal. It is important to understand the source of freshwater to Joe Bay before it enters Florida Bay. Taylor Slough transports freshwater to northeastern Florida Bay from the northwest while overflow from the C-111 Canal provides freshwater to northeastern Florida Bay from the northeast. Joe Bay, receives part of the freshwater from each of these sources via sheet flow and small estuarine creeks, and subsequently discharges southward to northeastern Florida Bay via Trout Creek. Trout Creek contributes approximately 50 percent of the total freshwater flow to northeastern Florida Bay (Hittle 2001). Eight non-gaged creeks entering Joe Bay were selected for acoustic Doppler current profiler (ADCP) measurements. The ADCP discharge measurements were then correlated with computed real-time discharge measurements from nearby USGS flow stations. Regression analysis was used to estimate flow at the Joe Bay creeks from June 1999 to April 2000. The R2 values for the estimated flow at eight Joe Bay creeks ranged between 0.51 and 0.93. From June 1999 to April 2000, flow volumes to eastern and western Joe Bay equaled 6.8 x 107m3 and 5.6 x 107 m3 respectively; flow into eastern Joe Bay was 21 percent greater than flow into western Joe Bay. Maximum freshwater discharge to Florida Bay occurred following Tropical Storm Harvey and Hurricane Irene, which occurred on September 21 1999, and October 15, 1999, respectively. Flow into western Joe Bay (3.5 x 107 m3) during the storms was 26 percent greater than flow into eastern Joe Bay (2.7 x 107 m3). However, dry season flow (January to April 2000) into eastern Joe Bay (2.6 x 107 m3) which was supplied primarily by the C-111 Canal, was much greater than flow into western Joe Bay (2.5 x 106 m3). Thus, the total flow into eastern Joe Bay exceeded total flow into western Joe Bay, even though western Joe Bay received more freshwater during storm events. During the storms, the S-197 structure was opened to allow the C-111 Canal to discharge outside of Florida Bay. This reduced the overflow from the C-111 Canal to both Joe and northeastern Florida Bays. Hittle, C.D., Patino, E, and Zucker, M. 2000, Freshwater Flow From Estuarine Creeks into Northeastern Florida Bay. U.S. Geological Survey Water-Resources Investigation 01-4164,p.32.
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Kish, George R.; Harrison, Arnell S.; Alderson, Mark
2008-01-01
The U.S. Geological Survey, in cooperation with the Sarasota Bay Estuary Program conducted a retrospective review of characteristics of the Sarasota Bay watershed in west-central Florida. This report describes watershed characteristics, surface- and ground-water processes, and the environmental setting of the Sarasota Bay watershed. Population growth during the last 50 years is transforming the Sarasota Bay watershed from rural and agriculture to urban and suburban. The transition has resulted in land-use changes that influence surface- and ground-water processes in the watershed. Increased impervious cover decreases recharge to ground water and increases overland runoff and the pollutants carried in the runoff. Soil compaction resulting from agriculture, construction, and recreation activities also decreases recharge to ground water. Conventional approaches to stormwater runoff have involved conveyances and large storage areas. Low-impact development approaches, designed to provide recharge near the precipitation point-of-contact, are being used increasingly in the watershed. Simple pollutant loading models applied to the Sarasota Bay watershed have focused on large-scale processes and pollutant loads determined from empirical values and mean event concentrations. Complex watershed models and more intensive data-collection programs can provide the level of information needed to quantify (1) the effects of lot-scale land practices on runoff, storage, and ground-water recharge, (2) dry and wet season flux of nutrients through atmospheric deposition, (3) changes in partitioning of water and contaminants as urbanization alters predevelopment rainfall-runoff relations, and (4) linkages between watershed models and lot-scale models to evaluate the effect of small-scale changes over the entire Sarasota Bay watershed. As urbanization in the Sarasota Bay watershed continues, focused research on water-resources issues can provide information needed by water-resources managers to ensure the future health of the watershed.
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NASA Astrophysics Data System (ADS)
Molnia, B. F.; Karpilo, R. D.; Pranger, H. S.
2004-12-01
Historical photographs, many dating from the late-19th century are being used to document landscape and glacier change in the Glacier Bay area. More than 350 pre-1980 photographs that show the Glacier Bay landscape and glacier termini positions have been acquired by the authors. Beginning in 2003, approximately 150 of the sites from which historical photographs had been made were revisited. At each site, elevation and latitude and longitude were recorded using WAAS-enabled GPS. Compass bearings to photographic targets were also determined. Finally, using the historical photographs as a composition guide, new photographs were exposed using digital imaging and film cameras. In the laboratory, 21st century images and photographs were compared with corresponding historical photographs to determine, and to better understand rates, timing, and mechanics of Glacier Bay landscape evolution, as well as to clarify the response of specific glaciers to changing climate and environment. The comparisons clearly document rapid vegetative succession throughout the bay; continued retreat of larger glaciers in the East Arm of the bay; a complex pattern of readvance and retreat of the larger glaciers in the West Arm of the bay, coupled with short-term fluctuations of its smaller glaciers; transitions from tidewater termini to stagnant, debris-covered termini; fiord sedimentation and erosion; development of outwash and talus features; and many other dramatic changes. As might be expected, 100-year-plus photo comparisons show significant changes throughout the Glacier Bay landscape, especially at the southern ends of East and West Arms. Surprisingly, recent changes, occurring since the late-1970s were equally dramatic, especially documenting the rapid thinning and retreat of glaciers in upper Muir Inlet.
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NASA Astrophysics Data System (ADS)
WU, Z. Y.; Saito, Y.; Milliman, J. D.; Zhao, D.; Zhou, J.
2015-12-01
Estuaries have been the site of intensive human activities. During the past century, decreased fluvial water and sediment discharge, increasing land reclamation, changing climate, and rising sea level have had an ever-increasing impact on river deltas, particularly those deltas bordering Southeast Asia. Using six stages of navigational and bathymetric chart data from 1906 to 2013 and 2 years (2012,2013) single-beam bathymetric data, together with more than 50 years of fluvial discharge data, we document the impact of human activities on the Pearl River Delta and its estuary at Lingding Bay. Between 1906 and 2010, land reclamation decreased the bay's water area by ~300 km2 (>17%), mostly at the expense of the shrinking intertidal and shallow subtidal mudflats. Before 1980, the estuary was mainly governed by natural processes with slight net deposition, whereas after 1980 dredging in the estuary and large port engineering projects changed the estuarine topography by shallowing the shoals and deepening the troughs. From 1955 to 2010, the water volume of Lingding Bay decreased by 536 × 106 m3 for a net decrease of 9.7 × 106 m3 a year, which indicates that approximately 9.7 Mt/yr of sediment was deposited in Lingding Bay during that period. In 2012 and 2013, large-scale human activities within Lingding Bay included continued dredging plus a surge of sand excavation that changed local water depths by ±5 m/yr, far exceeding the range of natural topographic evolution in the estuary. The impacts of various human activities have significantly changed submarine topography in Lingding Bay of the complex Pearl River Estuary. With continuing economic expansion in the Pearl River Delta, Lingding Bay should continue to shrink in both area and water volume.
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Poag, C. Wylie; Plescia, J.B.; Molzer, P.C.
2002-01-01
Three ancient impact craters (Chesapeake Bay - 35.7 Ma; Toms Canyon - 35.7 Ma; Montagnais - 51 Ma) and one multiring impact basin (Chicxulub - 65 Ma) are currently known to be buried beneath modern continental shelves. All occur on the passive Atlantic margin of North America in regions extensively explored by seismic reflection surveys in the search for oil and gas reserves. We limit our discussion herein to the three youngest structures. These craters were created by submarine impacts, which produced many structural and morphological features similar in construction, composition, and variability to those documented in well-preserved subaerial and planetary impact craters. The subcircular Chesapeake Bay (diameter 85 km) and ovate Montagnais (diameter 45-50 km) structures display outer-rim scarps, annular troughs, peak rings, inner basins, and central peaks similar to those incorporated in the widely cited conceptual model of complex impact craters. These craters differ in several respects from the model, however. For example, the Montagnais crater lacks a raised lip on the outer rim, the Chesapeake Bay crater displays only small remnants of a raised lip, and both craters contain an unusually thick body of impact breccia. The subtriangular Toms Canyon crater (diameter 20-22 km), on the other hand, contains none of the internal features of a complex crater, nor is it typical of a simple crater. It displays a prominent raised lip on the outer rim, but the lip is present only on the western side of the crater. In addition, each of these craters contains some distinct features, which are not present in one or both of the others. For example, the central peak at Montagnais rises well above the elevation of the outer rim, whereas at Chesapeake Bay, the outer rim is higher than the central peak. The floor of the Toms Canyon crater is marked by parallel deep troughs and linear ridges formed of sedimentary rocks, whereas at Chesapeake Bay, the crater floor contains concentric faults and compression ridges formed in rocks of the crystalline basement. The Chesapeake Bay crater is distinguished further by its cluster of at least 23 adjacent secondary craters. The North American tektite strewn field, a widespread deposit of distal ejecta, is thought to be derived from the Chesapeake Bay impact, perhaps with a small contribution from the Toms Canyon impact. No ejecta field is known to be associated with the Montagnais impact. No immediate major extinction event is directly linked to any of these three impacts. There is evidence, however, that the Chesapeake Bay and Toms Canyon impacts helped initiate a long-term pulse of warm global climate, whose eventual dissipation coincided with an early Oligocene mass extinction event, 2 Ma after the impacts.
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NASA Astrophysics Data System (ADS)
Calmet, Isabelle; Mestayer, Patrice G.; van Eijk, Alexander M. J.; Herlédant, Olivier
2018-04-01
We complete the analysis of the data obtained during the experimental campaign around the semi circular bay of Quiberon, France, during two weeks in June 2006 (see Part 1). A reanalysis of numerical simulations performed with the Advanced Regional Prediction System model is presented. Three nested computational domains with increasing horizontal resolution down to 100 m, and a vertical resolution of 10 m at the lowest level, are used to reproduce the local-scale variations of the breeze close to the water surface of the bay. The Weather Research and Forecasting mesoscale model is used to assimilate the meteorological data. Comparisons of the simulations with the experimental data obtained at three sites reveal a good agreement of the flow over the bay and around the Quiberon peninsula during the daytime periods of sea-breeze development and weakening. In conditions of offshore synoptic flow, the simulations demonstrate that the semi-circular shape of the bay induces a corresponding circular shape in the offshore zones of stagnant flow preceding the sea-breeze onset, which move further offshore thereafter. The higher-resolution simulations are successful in reproducing the small-scale impacts of the peninsula and local coasts (breeze deviations, wakes, flow divergences), and in demonstrating the complexity of the breeze fields close to the surface over the bay. Our reanalysis also provides guidance for numerical simulation strategies for analyzing the structure and evolution of the near-surface breeze over a semi-circular bay, and for forecasting important flow details for use in upcoming sailing competitions.
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Electrical Resistivity Imaging of Saltwater and Freshwater Along the Coast of Monterey Bay
NASA Astrophysics Data System (ADS)
Knight, R. J.; Pidlisecky, A.; Moran, T.; Goebel, M.
2014-12-01
A coastal region represents a dynamic interface where the processes of saltwater intrusion and freshwater flow create complex spatial and temporal changes in water chemistry. These changes in water chemistry affect both human use of coastal groundwater aquifers and the functioning of coastal ecosystems. Mapping out the subsurface distribution of saltwater and freshwater is a critical step in predicting, and managing, changes in water chemistry in coastal regions. Our research is focused on California's Monterey Bay region where agriculturally-intensive land meets the sensitive marine environment of the Monterey Bay National Marine Sanctuary. Along the coast of Monterey Bay extensive groundwater extraction (groundwater provides more than 80% of the area's water supply) has led to saltwater intrusion into aquifers at various locations. To date, the mapping of saltwater intrusion has relied on measurements of changing water chemistry in monitoring wells. But it is challenging with wells to capture the spatially complex hydrostratigraphy resulting from changing depositional environments and numerous faulting events. We suggest that geophysical methods be used to map and monitor the distribution of saltwater and freshwater by acquiring non-invasive, high-resolution continuous images of the subsurface. In a pilot study conducted over the past four years, we used electrical resistivity imaging to successfully identify regions of saltwater and freshwater 150 m below sea level along a 7 km stretch of the southern Monterey Bay coast. We employed large-offset electrical resistance tomography using a 96-electrode system with an overall array length of 860 m. The results showed excellent agreement with measurements in nearby monitoring wells. The large-scale image provided by the geophysical measurements revealed the hydrostratigraphic controls on the spatial distribution of the saltwater/freshwater interface. In October 2014 we will expand this study, using large-offset electrical resistance tomography to image to a depth of 300 m along a 40 km stretch of the Monterey Bay coast. The acquisition of this continuous dataset will provide an improved understanding of the biophysical and human factors controlling the processes of saltwater intrusion and freshwater flow in this coastal region.
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Perry, Matthew C.; Wells-Berlin, Alicia M.; Kidwell, David M.; Osenton, Peter C.
2007-01-01
Population and trophic relationships among diving ducks in Chesapeake Bay are diverse and complex as they include five species of bay ducks (Aythya spp.), nine species of seaducks (Tribe Mergini), and the Ruddy Duck (Oxyura jamaicensis). Here we considered the relationships between population changes and diet over the past half century to assess the importance of prey changes to wintering waterfowl in the Bay. Food habits of 643 diving ducks collected from Chesapeake Bay during 1999-2006 were determined by analyses of their gullet (esophagus and proventriculus) and gizzard contents and compared to historical data (1885-1979) of 1,541 diving ducks. Aerial waterfowl surveys, in general, suggest that six species of seaducks were more commonly located in the meso- to polyhaline areas of the Bay, whereas five species of bay ducks and Ruddy Ducks were in the oligo- to mesohaline areas. Seaducks fed on a molluscan diet of Hooked Mussel (Ischadium recurvum), Amethyst Gemclam (Gemma gemma), and Dwarf Surfclarn (Mulinia lateralis). Bay ducks and Ruddy Ducks fed more on Baltic Macoma (Macoma balthica), the adventive Atlantic Rangia (Rangia cuneata), and submerged aquatic vegetation (SAV). Mergansers were found over the widest salinity range in the Bay, probably because of their piscivorous diet. Each diving duck species appears to fill a unique foraging niche, although there is much overlap of selected prey. When current food habits are compared to historic data, only the Canvasback (Aythya valisineria) has had major diet changes, although SAV now accounts for less food volume for all diving duck species, except the Redhead (Aythya americana). Understanding the trophic-habitat relationships of diving ducks in coastal wintering areas will give managers a better understanding of the ecological effects of future environmental changes. Intensive restoration efforts on SAV and oyster beds should greatly benefit diving duck populations.
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Earth Observations taken by the Expedition 25 crew
2010-10-05
ISS025-E-006121 (5 Oct. 2010) --- Doha City, Doha Bay, State of Qatar and the Persian Gulf are featured in this image photographed by an Expedition 25 crew member on the International Space Station. The old and new zones of Doha, the capital city of the Persian Gulf state of Qatar, are visible in this photograph. The old city comprises the ancient bazaar, or Souq, near the dhow harbor (a dhow is a traditional Arab sailing vessel) which is still used today. Subsequent developments have taken place progressively further from the ancient center, with successive ring roads concentrically arranged around it. Modern port facilities can be seen immediately to the east of the Souq. The diplomatic quarter is reached via the Corniche promenade north of the old city. Yet further away an extensive marina complex known as West Bay Lagoon, with boating access to the Persian Gulf, stands out. Qatar’s new artificial island, known as the Pearl-Qatar, is under construction with 32 kilometers of new coastline, just offshore of West Bay Lagoon. This vast development is intended mainly as a residential zone with themes based on Arabic, Mediterranean and European cultures. The Pearl-Qatar complex is named for the fact that the new island is being built on one of Qatar’s major historical pearl diving sites. A string of small islands built along the outer margin of the complex is intended to recall the pearl-diving culture of the nation’s past.
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NASA Astrophysics Data System (ADS)
Watt, J. T.; Hardebeck, J.; Johnson, S. Y.; Kluesner, J.
2016-12-01
Characterizing active structures within structurally complex fault intersections is essential for unraveling the deformational history and for assessing the importance of fault intersections in regional earthquake hazard assessments. We employ an integrative, multi-scale geophysical approach to describe the 3D geometry and active tectonics of the offshore Los Osos fault (LOF) in Estero Bay, California. The shallow structure of the LOF, as imaged with multibeam and high-resolution seismic-reflection data, reveals a complex west-diverging zone of active faulting that bends into and joins the Hosgri fault. The down-dip geometry of the LOF as revealed by gravity, magnetic, and industry multi-channel seismic data, is vertical to steeply-dipping and varies along strike. As the LOF extends offshore, it is characterized by SW-side-up motion on a series of W-NW trending, steeply SW-dipping reverse faults. The LOF bends to the north ( 23°) as it approaches the Hosgri fault and dips steeply to the NE along a magnetic basement block. Inversion of earthquake focal mechanisms within Estero Bay yields maximum compressive stress axes that are near-horizontal and trend approximately N15E. This trend is consistent with dextral strike-slip faulting along NW-SE trending structures such as the Hosgri fault and northern LOF, and oblique dip-slip motion along the W-NW trending section of the LOF. Notably, NW-SE trending structures illuminated by seismicity in Estero Bay coincide with, but also appear to cross-cut, LOF structures imaged in the near-surface. We suggest this apparent disconnect reflects ongoing fault reorganization at a dynamic and inherently unstable fault intersection, in which the seismicity reflects active deformation at depth that is not clearly expressed in the near-surface geology. Direct connectivity between the Hosgri and Los Osos faults suggests a combined earthquake rupture is possible; however, the geometrical complexity along the offshore LOF may limit the extent of rupture.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Winston, G.O.
Examination of core samples and cuttings from seven wells in northern Cuba has shown that the southern margin of the Florida-Bahama platform is composed largely of dolomitized carbonate mound and talus material. Dolomitization is possibly due to reflux of the highly saline waters from the South Florida evaporite basin to the north. At least four separate episodes of mound construction are present, accompanied by seaward talus material. South of the dolomitized carbonate complex, three wells penetrated a deeper water continental slope facies consisting principally of light-colored limestone with uncommon beds of shale and radiolarian limestone. Zones of shallower facies appearmore » to be intercalated. Farther to the south beyond the scope of this study, volcanics and serpentine are reported in the literature. The northernmost wells on the island are cut by one or more high-angle thrust faults. Intense crumpling and faulting are present in the deeper water facies between the continental margin complex and the oceanic volcanic-serpentine province. The intense crumpling was probably caused as the deep-water sediments were scraped off by the subduction of an oceanic plate from the south beneath the continental crust of the Florida-Bahama platform. Certain beds in the northern Cuba carbonate complex can be correlated with the standard section in Florida, as exhibited in the Cay Sal well to the north. Three anhydrite beds in the Cayo Coco well appear to correlate with thick anhydrites in the Punto Gorda, Pumpkin Bay, and Bone Island formations. In the Collazo well to the south, a limestone-anhydrite section appears to correlate with the Pumpkin Bay. Three limestone intervals in the Blanquizal well seem to correlate with portions of the Rattlesnake Hammock, Pumpkin Bay, and Bone Island formations in the Cay Sal well.« less
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Goddard DEVELOP Students: Using NASA Remote Sensing Technology to Study the Chesapeake Bay Watershed
NASA Technical Reports Server (NTRS)
Moore, Rachel
2011-01-01
The DEVELOP National Program is an Earth Science research internship, operating under NASA s Applied Sciences Program. Each spring, summer, and fall, DEVELOP interns form teams to investigate Earth Science related issues. Since the Fall of 2003, Goddard Space Flight Center (GSFC) has been home to one of 10 national DEVELOP teams. In past terms, students completed a variety of projects related to the Applied Sciences Applications of National Priority, such as Public Health, Natural Disasters, Water Resources, and Ecological Forecasting. These projects have focused on areas all over the world, including the United States, Africa, and Asia. Recently, Goddard DEVELOP students have turned their attention to a local environment, the Chesapeake Bay Watershed. The Chesapeake Bay Watershed is a complex and diverse ecosystem, spanning approximately 64,000 square miles. The watershed encompasses parts of six states: Delaware, Maryland, New York, Pennsylvania, Virginia, and West Virginia, as well as the District of Columbia. The Bay itself is the biggest estuary in the United States, with over 100,000 tributaries feeding into it. The ratio of fresh water to salt water varies throughout the Bay, allowing for a variety of habitats. The Bay s wetlands, marshes, forests, reefs, and rivers support more than 3,600 plant and animal species, including birds, mammals, reptiles, amphibians, fish, and crabs. The Bay is also commercially significant. It is ranked third in the nation in fishery catch, and supplies approximately 500 million pounds of seafood annually. In addition to its abundant flora and fauna, the Chesapeake Bay watershed is home to approximately 16.6 million people, who live and work throughout the watershed, and who use its diverse resources for recreational purposes. Over the past several decades, the population throughout the watershed has increased rapidly, resulting in land use changes, and ultimately decreasing the health of the Chesapeake Bay Watershed. Over the course of 2009-2010, student teams carried out two independent research projects focused on the Chesapeake Bay Watershed. The first investigated the threat of invasive species to forests in Maryland. The second investigated the detection of winter cover crops throughout the watershed from satellite data.
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Factors contributing to variability in larval ingress of Atlantic menhaden, Brevoortia tyrannus
NASA Astrophysics Data System (ADS)
Lozano, C.; Houde, E. D.
2013-02-01
Annual recruitment levels of age-0 juvenile Atlantic menhaden to Chesapeake Bay, which historically supported >65% of coastwide recruitment, have been consistently low since the 1980s. Diminished larval supply to the Bay is one hypothesized explanation. In a three-year ichthyoplankton survey at the Chesapeake Bay mouth, abundance of ingressing larvae varied nine-fold among years. Larvae were most abundant in 2007-2008 and less abundant in 2005-2006 and 2006-2007. High month-to-month variability in larval concentrations was attributable primarily to seasonality of occurrences. There was no defined spatial pattern in distribution of larvae across the 18-km-wide Bay mouth, but larvae at the south side were longer and older on average than larvae at the middle and north side. Environmental variables measured at the times of larval collections were not correlated consistently with temporal and spatial variability in abundance of larvae at ingress, highlighting complexity and suggesting that abundance may be controlled by processes occurring offshore during the pre-ingress phase. Moreover, the substantial differences in inter-annual abundances of larvae at the Bay mouth were not concordant with subsequent abundances of age-0 juveniles in the three survey years, indicating that important processes affecting recruitment of Atlantic menhaden operate after ingress, during the larval to juvenile transition stage.
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A nowcast model for tides and tidal currents in San Francisco Bay, California
Cheng, Ralph T.; Smith, Richard E.
1998-01-01
National Oceanographic and Atmospheric Administration (NOAA) installed Physical Oceanographic Real-Time System (PORTS) in San Francisco Bay, California to provide observations of tides, tidal currents, and meteorological conditions. PORTS data are used for optimizing vessel operations, increasing margin of safety for navigation, and guiding hazardous material spill prevention and response. Because tides and tidal currents in San Francisco Bay are extremely complex, limited real-time observations are insufficient to provide spatial resolution for variations of tides and tidal currents. To fill the information gaps, a highresolution, robust, semi-implicit, finite-difference nowcast numerical model has been implemented for San Francisco Bay. The model grid and water depths are defined on coordinates based on Mercator projection so the model outputs can be directly superimposed on navigation charts. A data assimilation algorithm has been established to derive the boundary conditions for model simulations. The nowcast model is executed every hour continuously for tides and tidal currents starting from 24 hours before the present time (now) covering a total of 48 hours simulation. Forty-eight hours of nowcast model results are available to the public at all times through the World Wide Web (WWW). Users can view and download the nowcast model results for tides and tidal current distributions in San Francisco Bay for their specific applications and for further analysis.
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Ecology of southeastern shrub bogs (pocosins) and Carolina bays: a community profile
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sharitz, R.R.; Gibbons, J.W.
1982-11-01
Shrub bogs of the Southeast occur in areas of poorly developed internal drainage that typically but not always have highly developed organic or peat soils. Pocosins and Carolina bays are types or subclasses of shrub bogs on the coastal plains of the Carolinas and Georgia. They share roughly the same distribution patterns, soil types, floral and faunal species composition and other community attributes, but differ in geological formation. Carolina bays may contain pocosin as well as other communities, but are defined more by their unique elliptical shape and geomorphometry. The pocosin community is largely defined by its vegetation, a combinationmore » of a dense shrub understory and a sparser canopy. The community is part of a complex successional sequence of communities (sedge bogs, savannas, cedar bogs, and bay forests) that may be controlled by such factors as fire, hydroperiod, soil type, and peat depth. Pocosins and Carolina bays harbor a number of animal groups and may be locally important in their ecology. Although few species are endemic to these habitats, they may provide important refuges for a number of species. These communities are simultaneously among the least understood and most rapidly disappearing habitats of the Southeast. Forestry and agricultural clearage are current impacts.« less
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Drivers of Variability of Diel-Cycling and Episodic Hypoxia In ...
Eutrophication of coastal ecosystems is a longstanding environmental concern, exacerbated by population growth and associated nutrient pollution, and ultimately resulting in increased incidence of hypoxia. Shallow and highly productive estuaries and embayments are particularly susceptible to diel-cycling hypoxia, associated with day-night cycles of production and respiration, which can cause extreme excursions in dissolved oxygen (DO) concentrations from anoxia to super-saturation within a single day. Diel oxygen dynamics in these systems are complex, and may be influenced by wind forcing, vertical and horizontal mixing, variation in freshwater inflow, cloud cover, and temperature. To better understand the environmental drivers of periodic hypoxia, this study examined four northern Gulf of Mexico Estuaries (Weeks Bay, AL; Wolf Bay, AL; Fowl River, AL; and St. Louis Bay, MS). Dissolved oxygen varied strongly on a diel basis in all four systems, with periods of sustained low oxygen (>24 h) observed in both Weeks Bay and Wolf Bay. The duration and persistence of hypoxia further varied in response to changing salinity regimes and regional weather. These results underscore the dynamic nature of hypoxia in shallow estuarine systems, and highlight the importance of combining fixed site continuous monitoring data with spatial hydrographic surveys to accurately resolve DO dynamics. This abstract is submitted for presentation at the CERF conference held Nov 8-12 in Oregon
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Wolf, S.C.
1970-01-01
In Monterey Bay, the highest concentrations of medium and fine sands occur nearshore between ten and thirty fathoms. Silt and clay accumulate in greater depths. Contours of median diameter roughly parallel the isobaths. Fine-grained materials are supplied to the bay region from erosion of cliffs which partly surround Monterey Bay, from sediment laden river discharge, and from continual reworking of widespread Pleistocene and Recent sea floor sediments. These sediments in turn are picked up by coastal currents and distributed over the shelf regions by present day current regimes. Studies of bottom currents over the shelf regions and in Monterey Canyon have revealed patterns which vary with seasonal changes. Current patterns during August and September exhibit remarkable symmetry about the axis of Monterey Submarine Canyon. Central Shelf currents north and south of Monterey Canyon flowed northwest at an average rate of 0.2 knots and south at 0.3 knots respectively. On the North Shelf between January and March currents flowed east to southeast at 0.3-0.5 knots with mirror image patterns above the South Shelf during the same period. Irregular current flow in the canyon indicates a complex current structure with frequent shifts in counterclockwise and clockwise direction over very short periods of time. Bottom topography of the canyon complex often causes localization of canyon currents. One particular observation at a depth of 51 fathoms indicated up-canyon flow at a rate of 0.2 knots. Most of the observed currents are related to seasonal variations, upwelling, ocean swell patterns, and to changes in the California and Davidson currents. Changes in current regimes are reflected in the patterns of sediment distribution and transport. Sediment transport is chiefly parallel to the isobaths, particularly on the North and South Shelf regions. Complex dispersal patterns are observed near Monterey Canyon and Moss Landing Harbor jetties. Longshore currents move sediments southward except near Monterey Canyon which acts as a physiographic barrier and the extreme southern end of the bay where currents are non persistent. Some sediments are also transported offshore by rip currents and other agencies and deposited in deeper, quieter waters. Supply of sediments to the canyon head results in over-filling and steepening with subsequent mass movement of sediments seaward followed by deposition in channels and on the broad deep sea fan. ?? 1970.
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View of front of garage, detail of building number over ...
View of front of garage, detail of building number over bay 4. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA
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Triple Value Simulation Model Fact Sheet
The Triple Value Simulation (3VS) is a high-level model that accounts for the complex relationships among economic, social and environmental systems in order to explore scenarios and solutions to improve the health of the Bay.
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Birch, G F; Gunns, T J; Chapman, D; Harrison, D
2016-05-01
As coastal populations increase, considerable pressures are exerted on estuarine environments. Recently, there has been a trend towards the development and use of estuarine assessment schemes as a decision support tool in the management of these environments. These schemes offer a method by which complex environmental data is converted into a readily understandable and communicable format for informed decision making and effective distribution of limited management resources. Reliability and effectiveness of these schemes are often limited due to a complex assessment framework, poor data management and use of ineffective environmental indicators. The current scheme aims to improve reliability in the reporting of estuarine condition by including a concise assessment framework, employing high-value indicators and, in a unique approach, employing fuzzy logic in indicator evaluation. Using Sydney estuary as a case study, each of the 15 sub-catchment/sub-estuary systems were assessed using the current scheme. Results identified that poor sediment quality was a significant issue in Blackwattle/Rozelle Bay, Iron Cove and Hen and Chicken Bay while poor water quality was of particular concern in Duck River, Homebush Bay and the Parramatta River. Overall results of the assessment scheme were used to prioritise the management of each sub-catchment/sub-estuary assessed with Blackwattle/Rozelle Bay, Homebush Bay, Iron Cove and Duck River considered to be in need of a high priority management response. A report card format, using letter grades, was employed to convey the results of the assessment in a readily understood manner to estuarine managers and members of the public. Letter grades also provide benchmarking and performance monitoring ability, allowing estuarine managers to set improvement targets and assesses the effectiveness of management strategies. The current assessment scheme provides an effective, integrated and consistent assessment of estuarine health and provides an effective decision support tool to maximise the efficient distribution of limited management resources.
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Empirical Bayes scan statistics for detecting clusters of disease risk variants in genetic studies.
McCallum, Kenneth J; Ionita-Laza, Iuliana
2015-12-01
Recent developments of high-throughput genomic technologies offer an unprecedented detailed view of the genetic variation in various human populations, and promise to lead to significant progress in understanding the genetic basis of complex diseases. Despite this tremendous advance in data generation, it remains very challenging to analyze and interpret these data due to their sparse and high-dimensional nature. Here, we propose novel applications and new developments of empirical Bayes scan statistics to identify genomic regions significantly enriched with disease risk variants. We show that the proposed empirical Bayes methodology can be substantially more powerful than existing scan statistics methods especially so in the presence of many non-disease risk variants, and in situations when there is a mixture of risk and protective variants. Furthermore, the empirical Bayes approach has greater flexibility to accommodate covariates such as functional prediction scores and additional biomarkers. As proof-of-concept we apply the proposed methods to a whole-exome sequencing study for autism spectrum disorders and identify several promising candidate genes. © 2015, The International Biometric Society.
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Mauad, Cristiane R; Wagener, Angela de L R; Massone, Carlos G; Aniceto, Mayara da S; Lazzari, Letícia; Carreira, Renato S; Farias, Cássia de O
2015-02-15
Aliphatic (n-C12-n-C40, unresolved complex mixture, resolved peaks) and aromatic hydrocarbons (46 PAH) were investigated in suspended particulate matter (SPM) sampled over eleven months in six of the major rivers and two channels of the Guanabara Bay Basin. PAH flow rates of the most contaminated rivers, the contribution to the PAH sediment load of the receiving bay, and the main sources of hydrocarbons were determined. PAH (38) ranged from 28 ng L(-1) to 11,514 ng L(-1). Hydrocarbon typology and statistical evaluation demonstrated contribution of distinct sources in different regions and allowed quantification of these contributions. Total flow rate for the five major rivers amounts to 3 t year(-1) and responds for 30% of the total PAH annual input into the northern area of the Guanabara Bay. For the first time PAH mass deposited in the bay sediments has been estimated and shall serve as base for decision making and source abatement. Copyright © 2014 Elsevier B.V. All rights reserved.
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Poag, C. Wylie; Hutchinson, Deborah R.; Colman, Steve M.; Lee, Myung W.; Dressler, B.O.; Sharpton, V.L.
1999-01-01
This work refines previous interpretations of the structure and morphology of the Chesapeake Bay impact crater on the basis of more than 1,200 km of multichannel and single-channel seismic reflection profiles collected in the bay and on the adjacent continental shelf. The outer rim, formed in sedimentary rocks, is irregularly circular, with an average diameter of ~85 km. A 20–25-km-wide annular trough separates the outer rim from an ovate, crystalline peak ring of ~200 m of maximum relief. The inner basin is 35–40 km in diameter, and at least 1.26 km deep. A crystalline(?) central peak, approximately 1 km high, is faintly imaged on three profiles, and also is indicated by a small positive Bouguer gravity anomaly. These features classify the crater as a complex peak-ring/central peak crater. Chesapeake Bay Crater is most comparable to the Ries and Popigai Craters on Earth; to protobasins on Mars, Mercury, and the Moon; and to type D craters on Venus.
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NASA Astrophysics Data System (ADS)
Gao, Xuelu; Chen, Shaoyong
2008-10-01
Nine surface sediments collected from Daya Bay have been Soxhlet-extracted with 2:1 (v/v) dichloromethane-methanol. The non-aromatic hydrocarbon (NAH) fraction of solvent extractable organic matter (EOM) and some bulk geochemical parameters have been analyzed to determine petroleum pollution of the bay. The NAH content varies from 32 to 276 μg g -1 (average 104 μg g -1) dry sediment and accounts for 5.8-64.1% (average 41.6%) of the EOM. n-Alkanes with carbon number ranging from 15 to 35 are identified to be derived from both biogenic and petrogenic sources in varying proportions. The contribution of marine authigenic input to the sedimentary n-alkanes is lower than the allochthonous input based on the average n-C 31/ n-C 19 alkane ratio. 25.6-46.5% of the n-alkanes, with a mean of 35.6%, are contributed by vascular plant wax. Results of unresolved complex mixture, isoprenoid hydrocarbons, hopanes and steranes also suggest possible petroleum contamination. There is strong evidence of a common petroleum contamination source in the bay.
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Doan, Phuong T K; Watson, Sue B; Markovic, Stefan; Liang, Anqi; Guo, Jay; Mugalingam, Shan; Stokes, Jonathan; Morley, Andrew; Zhang, Weitao; Arhonditsis, George B; Dittrich, Maria
2018-04-24
Internal phosphorus (P) loading significantly contributes to hysteresis in ecosystem response to nutrient remediation, but the dynamics of sediment P transformations are often poorly characterized. Here, we applied a reaction-transport diagenetic model to investigate sediment P dynamics in the Bay of Quinte, a polymictic, spatially complex embayment of Lake Ontario, (Canada). We quantified spatial and temporal variability of sediment P binding forms and estimated P diffusive fluxes and sediment P retention in different parts of the bay. Our model supports the notion that diagenetic recycling of redox sensitive and organic bound P forms drive sediment P release. In the recent years, summer sediment P diffusive fluxes varied in the range of 3.2-3.6 mg P m -2 d -1 in the upper bay compared to 1.5 mg P m -2 d -1 in the middle-lower bay. Meanwhile sediment P retention ranged between 71% and 75% in the upper and middle-lower bay, respectively. The reconstruction of temporal trends of internal P loading in the past century, suggests that against the backdrop of reduced external P inputs, sediment P exerts growing control over the lake nutrient budget. Higher sediment P diffusive fluxes since mid-20th century with particular increase in the past 20 years in the shallower upper basins, emphasize limited sediment P retention potential and suggest prolonged ecosystem recovery, highlighting the importance of ongoing P control measures. Copyright © 2018 Elsevier B.V. All rights reserved.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Taiping; Yang, Zhaoqing; Khangaonkar, Tarang
2010-04-22
In this study, a hydrodynamic model based on the unstructured-grid finite volume coastal ocean model (FVCOM) was developed for Bellingham Bay, Washington. The model simulates water surface elevation, velocity, temperature, and salinity in a three-dimensional domain that covers the entire Bellingham Bay and adjacent water bodies, including Lummi Bay, Samish Bay, Padilla Bay, and Rosario Strait. The model was developed using Pacific Northwest National Laboratory’s high-resolution Puget Sound and Northwest Straits circulation and transport model. A sub-model grid for Bellingham Bay and adjacent coastal waters was extracted from the Puget Sound model and refined in Bellingham Bay using bathymetric lightmore » detection and ranging (LIDAR) and river channel cross-section data. The model uses tides, river inflows, and meteorological inputs to predict water surface elevations, currents, salinity, and temperature. A tidal open boundary condition was specified using standard National Oceanic and Atmospheric Administration (NOAA) predictions. Temperature and salinity open boundary conditions were specified based on observed data. Meteorological forcing (wind, solar radiation, and net surface heat flux) was obtained from NOAA real observations and National Center for Environmental Prediction North American Regional Analysis outputs. The model was run in parallel with 48 cores using a time step of 2.5 seconds. It took 18 hours of cpu time to complete 26 days of simulation. The model was calibrated with oceanographic field data for the period of 6/1/2009 to 6/26/2009. These data were collected specifically for the purpose of model development and calibration. They include time series of water-surface elevation, currents, temperature, and salinity as well as temperature and salinity profiles during instrument deployment and retrieval. Comparisons between model predictions and field observations show an overall reasonable agreement in both temporal and spatial scales. Comparisons of root mean square error values for surface elevation, velocity, temperature, and salinity time series are 0.11 m, 0.10 m/s, 1.28oC, and 1.91 ppt, respectively. The model was able to reproduce the salinity and temperature stratifications inside Bellingham Bay. Wetting and drying processes in tidal flats in Bellingham Bay, Samish Bay, and Padilla Bay were also successfully simulated. Both model results and observed data indicated that water surface elevations inside Bellingham Bay are highly correlated to tides. Circulation inside the bay is weak and complex and is affected by various forcing mechanisms, including tides, winds, freshwater inflows, and other local forcing factors. The Bellingham Bay model solution was successfully linked to the NOAA oil spill trajectory simulation model “General NOAA Operational Modeling Environment (GNOME).” Overall, the Bellingham Bay model has been calibrated reasonably well and can be used to provide detailed hydrodynamic information in the bay and adjacent water bodies. While there is room for further improvement with more available data, the calibrated hydrodynamic model provides useful hydrodynamic information in Bellingham Bay and can be used to support sediment transport and water quality modeling as well as assist in the design of nearshore restoration scenarios.« less
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NASA Astrophysics Data System (ADS)
Thompson, D. E.; Rajkumar, T.
2002-12-01
The San Francisco Bay Delta is a large hydrodynamic complex that incorporates the Sacramento and San Joaquin Estuaries, the Suisan Marsh, and the San Francisco Bay proper. Competition exists for the use of this extensive water system both from the fisheries industry, the agricultural industry, and from the marine and estuarine animal species within the Delta. As tidal fluctuations occur, more saline water pushes upstream allowing fish to migrate beyond the Suisan Marsh for breeding and habitat occupation. However, the agriculture industry does not want extensive salinity intrusion to impact water quality for human and plant consumption. The balance is regulated by pumping stations located along the estuaries and reservoirs whereby flushing of fresh water keeps the saline intrusion at bay. The pumping schedule is driven by data collected at various locations within the Bay Delta and by numerical models that predict the salinity intrusion as part of a larger model of the system. The Interagency Ecological Program (IEP) for the San Francisco Bay / Sacramento-San Joaquin Estuary collects, monitors, and archives the data, and the Department of Water Resources provides a numerical model simulation (DSM2) from which predictions are made that drive the pumping schedule. A problem with DSM2 is that the numerical simulation takes roughly 16 hours to complete a prediction. We have created a neural net, optimized with a genetic algorithm, that takes as input the archived data from multiple gauging stations and predicts stage, salinity, and flow at the Carquinez Straits (at the downstream end of the Suisan Marsh). This model seems to be robust in its predictions and operates much faster than the current numerical DSM2 model. Because the Bay-Delta is strongly tidally driven, we used both Principal Component Analysis and Fast Fourier Transforms to discover dominant features within the IEP data. We then filtered out the dominant tidal forcing to discover non-primary tidal effects, and used this to enhance the neural network by mapping input-output relationships in a more efficient manner. Furthermore, the neural network implicitly incorporates both the hydrodynamic and water quality models into a single predictive system. Although our model has not yet been enhanced to demonstrate improve pumping schedules, it has the possibility to support better decision-making procedures that may then be implemented by State agencies if desired. Our intention is now to use our calibrated Bay-Delta neural model in the smaller Elkhorn Slough complex near Monterey Bay where no such hydrodynamic model currently exists. At the Elkhorn Slough, we are fusing the neural net model of tidally-driven flow with in situ flow data and airborne and satellite remote sensing data. These further constrain the behavior of the model in predicting the longer-term health and future of this vital estuary. In particular, we are using visible data to explore the effects of the sediment plume that wastes into Monterey Bay, and infrared data and thermal emissivities to characterize the plant habitat along the margins of the Slough as salinity intrusion and sediment removal change the boundary of the estuary. The details of the Bay-Delta neural net model and its application to the Elkhorn Slough are presented in this paper.
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Stratification of Seismic Anisotropy Beneath Hudson Bay
NASA Astrophysics Data System (ADS)
Darbyshire, F. A.; Eaton, D. W.; Bastow, I. D.
2012-12-01
The Hudson Bay region has a complex tectonic history spanning ~4 Ga of Earth's evolution. During the ~1.8 Ga Trans-Hudson orogeny, the Archean Superior and Western Churchill cratons collided following the subduction of a Pacific-scale ocean. It is thought that a significant amount of juvenile material is preserved in the Trans-Hudson Orogen, in part due to the complex double-indentor geometry of the Superior-Churchill collision. In the region of interest, the orogen lies beneath a large but shallow Paleozoic intra-cratonic basin. Studies of the crust and upper mantle beneath this region have been enabled through the HuBLE (Hudson Bay Lithospheric Experiment) project, through the deployment of broadband seismographs around the Bay and across the islands to the north. A surface-wave tomography study has taken advantage of the data coverage, providing new information on phase velocity heterogeneity and anisotropy for wave periods of 25-200 seconds (equivalent to depths from the lower crust to ~300 km). On a large scale, our results show that the entire region is underlain by a seismically fast lithospheric lid corresponding to the continental keel. The lithospheric thickness ranges from ~180km in the northeast, beneath a zone of Paleozoic rifting, to ~280km beneath central Hudson Bay. Within the lithosphere, seismic velocities vary laterally, including high-velocity material wrapping around the Bay in the uppermost mantle. In the mid-lithosphere, two high-velocity cores are imaged, with a zone of lower velocity between them beneath the Bay. We interpret these high-velocity structures to represent the strongest central cores of the Superior and Churchill cratons, with more-juvenile material preserved between them. The near-vertical geometry of the lower-velocity zone suggests that it is only the effects of terminal collision of the cratonic cores, rather than any preceding subduction, that is preserved today. The lowermost lithosphere has a more uniform velocity, and may represent a pervasive zone of metasomatism or underplating. Anisotropy patterns across the region also vary with depth, suggesting ~3 layers of stratification of lithospheric fabric. At the shallowest depths, anisotropic fast directions wrap around the Bay in a similar fashion to the patterns of isotropic wavespeed. The upper lithospheric mantle below is characterized by relatively weak and incoherent anisotropy; however the mid-to-lower lithosphere shows stronger anisotropy, with a pattern of fast directions broadly consistent with the tectonics of the Superior-Churchill collision as inferred from potential-field data. This may suggest some degree of coherency of deformation between the crust, uppermost mantle and lower lithosphere. These models of seismic wavespeed variation beneath the Hudson Bay region reveal the preservation of a major collision zone during the assembly of the Laurentian continental mass, and also suggest that the Archean cratons can be subdivided into different lithospheric domains that reflect their tectonic history but do not necessarily correspond to surface geological boundaries.
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Ansmann, Ina C; Parra, Guido J; Lanyon, Janet M; Seddon, Jennifer M
2012-09-01
Highly mobile marine species in areas with no obvious geographic barriers are expected to show low levels of genetic differentiation. However, small-scale variation in habitat may lead to resource polymorphisms and drive local differentiation by adaptive divergence. Using nuclear microsatellite genotyping at 20 loci, and mitochondrial control region sequencing, we investigated fine-scale population structuring of inshore bottlenose dolphins (Tursiops aduncus) inhabiting a range of habitats in and around Moreton Bay, Australia. Bayesian structure analysis identified two genetic clusters within Moreton Bay, with evidence of admixture between them (F(ST) = 0.05, P = 0.001). There was only weak isolation by distance but one cluster of dolphins was more likely to be found in shallow southern areas and the other in the deeper waters of the central northern bay. In further analysis removing admixed individuals, southern dolphins appeared genetically restricted with lower levels of variation (AR = 3.252, π = 0.003) and high mean relatedness (r = 0.239) between individuals. In contrast, northern dolphins were more diverse (AR = 4.850, π = 0.009) and were mixing with a group of dolphins outside the bay (microsatellite-based STRUCTURE analysis), which appears to have historically been distinct from the bay dolphins (mtDNA Φ(ST) = 0.272, P < 0.001). This study demonstrates the ability of genetic techniques to expose fine-scale patterns of population structure and explore their origins and mechanisms. A complex variety of inter-related factors including local habitat variation, differential resource use, social behaviour and learning, and anthropogenic disturbances are likely to have played a role in driving fine-scale population structure among bottlenose dolphins in Moreton Bay. © 2012 Blackwell Publishing Ltd.
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Cyclin-dependent kinase 9 is a novel specific molecular target in adult T-cell leukemia/lymphoma.
Narita, Tomoko; Ishida, Takashi; Ito, Asahi; Masaki, Ayako; Kinoshita, Shiori; Suzuki, Susumu; Takino, Hisashi; Yoshida, Takashi; Ri, Masaki; Kusumoto, Shigeru; Komatsu, Hirokazu; Imada, Kazunori; Tanaka, Yuetsu; Takaori-Kondo, Akifumi; Inagaki, Hiroshi; Scholz, Arne; Lienau, Philip; Kuroda, Taruho; Ueda, Ryuzo; Iida, Shinsuke
2017-08-31
Cyclin-dependent kinase 9 (CDK9), a subunit of the positive transcription elongation factor b (P-TEFb) complex, regulates gene transcription elongation by phosphorylating the C-terminal domain (CTD) of RNA polymerase II (RNAPII). The deregulation of CDK9/P-TEFb has important implications for many cancer types. BAY 1143572 is a novel and highly selective CDK9/P-TEFb inhibitor currently being investigated in phase 1 studies. We evaluated the therapeutic potential of BAY 1143572 in adult T-cell leukemia/lymphoma (ATL). As a result of CDK9 inhibition and subsequent inhibition of phosphorylation at serine 2 of the RNAPII CTD, BAY 1143572 decreased c-Myc and Mcl-1 levels in ATL-derived or human T-cell lymphotropic virus type-1 (HTLV-1)-transformed lines and primary ATL cells tested, leading to their growth inhibition and apoptosis. Median inhibitory concentrations for BAY 1143572 in ATL-derived or HTLV-1-transformed lines (n = 8), primary ATL cells (n = 11), and CD4 + cells from healthy volunteers (n = 5) were 0.535, 0.30, and 0.36 μM, respectively. Next, NOG mice were used as recipients of tumor cells from an ATL patient. BAY 1143572-treated ATL-bearing mice (once daily 12.5 mg/kg oral application) demonstrated significantly decreased ATL cell infiltration of the liver and bone marrow, as well as decreased human soluble interleukin-2 receptor levels in serum (reflecting the ATL tumor burden), compared with untreated mice (n = 8 for both). BAY 1143572-treated ATL-bearing mice demonstrated significantly prolonged survival compared with untreated ATL-bearing mice (n = 7 for both). Collectively, this study indicates that BAY 1143572 showed strong potential as a novel treatment of ATL. © 2017 by The American Society of Hematology.
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Colman, Steven M.; Baucom, P.C.; Bratton, J.F.; Cronin, T. M.; McGeehin, J.P.; Willard, D.; Zimmerman, A.R.; Vogt, P.R.
2002-01-01
Rapidly accumulating Holocene sediments in estuaries commonly are difficult to sample and date. In Chesapeake Bay, we obtained sediment cores as much as 20 m in length and used numerous radiocarbon ages measured by accelarator mass spectrometry methods to provide the first detailed chronologies of Holocene sediment accumulation in the bay. Carbon in these sediments is a complex mixture of materials from a variety of sources. Analyses of different components of the sediments show that total organic carbon ages are largely unreliable, because much of the carbon (including coal) has been transported to the bay from upstream sources and is older than sediments in which it was deposited. Mollusk shells (clams, oysters) and foraminifera appear to give reliable results, although reworking and burrowing are potential problems. Analyses of museum specimens collected alive before atmospheric nuclear testing suggest that the standard reservoir correction for marine samples is appropriate for middle to lower Chesapeake Bay. The biogenic carbonate radiocarbon ages are compatible with 210 Pb and 137 Cs data and pollen stratigraphy from the same sites. Post-settlement changes in sediment transport and accumulation is an important environmental issue in many estuaries, including the Chesapeake. Our data show that large variations in sediment mass accumulation rates occur among sites. At shallow water sites, local factors seem to control changes in accumulation rates with time. Our two relatively deep-water sites in the axial channel of the bay have different long-term average accumulation rates, but the history of sediment accumulation at these sites appears to reflect overall conditions in the bay. Mass accumulation rates at the two deep-water sites rapidly increased by about fourfold coincident with widespread land clearance for agriculture in the Chesapeake watershed.
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Integrating Fluvial and Oceanic Drivers in Operational Flooding Forecasts for San Francisco Bay
NASA Astrophysics Data System (ADS)
Herdman, Liv; Erikson, Li; Barnard, Patrick; Kim, Jungho; Cifelli, Rob; Johnson, Lynn
2016-04-01
The nine counties that make up the San Francisco Bay area are home to 7.5 million people and these communties are susceptible to flooding along the bay shoreline and inland creeks that drain to the bay. A forecast model that integrates fluvial and oceanic drivers is necessary for predicting flooding in this complex urban environment. The U.S. Geological Survey ( USGS) and National Weather Service (NWS) are developing a state-of-the-art flooding forecast model for the San Francisco Bay area that will predict watershed and ocean-based flooding up to 72 hours in advance of an approaching storm. The model framework for flood forecasts is based on the USGS-developed Coastal Storm Modeling System (CoSMoS) that was applied to San Francisco Bay under the Our Coast Our Future project. For this application, we utilize Delft3D-FM, a hydrodynamic model based on a flexible mesh grid, to calculate water levels that account for tidal forcing, seasonal water level anomalies, surge and in-Bay generated wind waves from the wind and pressure fields of a NWS forecast model, and tributary discharges from the Research Distributed Hydrologic Model (RDHM), developed by the NWS Office of Hydrologic Development. The flooding extent is determined by overlaying the resulting water levels onto a recently completed 2-m digital elevation model of the study area which best resolves the extensive levee and tidal marsh systems in the region. Here we present initial pilot results of hindcast winter storms in January 2010 and December 2012, where the flooding is driven by oceanic and fluvial factors respectively. We also demonstrate the feasibility of predicting flooding on an operational time scale that incorporates both atmospheric and hydrologic forcings.
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Ley, Janet A.; McIvor, Carole C.; Peebles, Ernst B; Rolls, Holly; Cooper, Suzanne T.
2009-01-01
Fishing in Tampa Bay enhances the quality of life of the area's residents and visitors. However, people's desire to settle along the Bay's shorelines and tributaries has been detrimental to the very habitat believed to be crucial to prime target fishery species. Common snook (Centropomus undecimalis) and red drum (Sciaenops ocellatus) are part of the suite of estuarine fishes that 1) are economically or ecologically prominent, and 2) have complex life cycles involving movement between open coastal waters and estuarine nursery habitats, including nursery habitats that are located within upstream, low-salinity portions of the Bay?s tidal tributaries. We are using an emerging microchemical technique -- elemental fingerprinting of fish otoliths -- to determine the degree to which specific estuarine locations contribute to adult fished populations in Tampa Bay. In ongoing monitoring surveys, over 1,000 young-of-the-year common snook and red drum have already been collected from selected Tampa Bay tributaries. Using laser ablation-inductively coupled plasma - mass spectrometry (LA-ICP-MS), we are currently processing a subsample of these archived otoliths to identify location-specific fingerprints based on elemental microchemistry. We will then analyze older fish from the local fishery in order to match them to their probable nursery areas, as defined by young-of-the-year otoliths. We expect to find that some particularly favorable nursery locations contribute disproportionately to the fished population. In contrast, other nursery areas may be degraded, or act as 'sinks', thereby decreasing their contribution to the fish population. Habitat managers can direct strategic efforts to protect any nursery locations that are found to be of prime importance in contributing to adult stocks.
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Bayes factors for testing inequality constrained hypotheses: Issues with prior specification.
Mulder, Joris
2014-02-01
Several issues are discussed when testing inequality constrained hypotheses using a Bayesian approach. First, the complexity (or size) of the inequality constrained parameter spaces can be ignored. This is the case when using the posterior probability that the inequality constraints of a hypothesis hold, Bayes factors based on non-informative improper priors, and partial Bayes factors based on posterior priors. Second, the Bayes factor may not be invariant for linear one-to-one transformations of the data. This can be observed when using balanced priors which are centred on the boundary of the constrained parameter space with a diagonal covariance structure. Third, the information paradox can be observed. When testing inequality constrained hypotheses, the information paradox occurs when the Bayes factor of an inequality constrained hypothesis against its complement converges to a constant as the evidence for the first hypothesis accumulates while keeping the sample size fixed. This paradox occurs when using Zellner's g prior as a result of too much prior shrinkage. Therefore, two new methods are proposed that avoid these issues. First, partial Bayes factors are proposed based on transformed minimal training samples. These training samples result in posterior priors that are centred on the boundary of the constrained parameter space with the same covariance structure as in the sample. Second, a g prior approach is proposed by letting g go to infinity. This is possible because the Jeffreys-Lindley paradox is not an issue when testing inequality constrained hypotheses. A simulation study indicated that the Bayes factor based on this g prior approach converges fastest to the true inequality constrained hypothesis. © 2013 The British Psychological Society.
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Alaskan seismic gap only partially filled by 28 February 1979 earthquake
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lahr, J.C.; Stephens, C.D.; Hasegawa, H.S.
1980-03-21
The Saint Elias, Alaska, earthquake (magnitude 7.7) of 28 February 1979 is the first major earthquake since 1900 to occur along the complex Pacific-North American plate boundary between Yakutat Bay and Prince William Sound. This event involved complex rupture on a shallow, low-angle, north-dipping fault beneath the Chugach and Saint Elias Mountains. The plate boundary between Yakutat Bay and Prince William Sound had been identified as a seismic gap, an area devoid of major earthquakes during the last few decades, and was thought to be a likely site for a future major earthquake. Since the Saint Elias earthquake fills onlymore » the eastern quarter of the gap, the remainder of the gap to the west is a prime area for the study of precursory and coseismic phenomena associated with large earthquakes. 1 figure, 1 table.« less
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Organic carbon balance and net ecosystem metabolism in Chesapeake Bay
Kemp, W.M.; Smith, E.M.; Marvin-DiPasquale, M.; Boynton, W.R.
1997-01-01
The major fluxes of organic carbon associated with physical transport and biological metabolism were compiled, analyzed and compared for the mainstem portion of Chesapeake Bay (USA). In addition, 5 independent methods were used to calculate the annual mean net ecosystem metabolism (NEM = production - respiration) for the integrated Bay. These methods, which employed biogeochemical models, nutrient mass-balances anti summation of individual organic carbon fluxes, yielded remarkably similar estimates, with a mean NEM of +50 g C m-2 yr-1 (?? SE = 751, which is approximately 8% of the estimated annual average gross primary production. These calculations suggest a strong cross-sectional pattern in NEM throughout the Bay, wherein net heterotrophic metabolism prevails in the pelagic zones of the main channel, while net autotrophy occurs in the littoral zones which flank the deeper central area. For computational purposes, the estuary was separated into 3 regions along the land-sea gradient: (1) the oligohaline Upper Bay (11% of total area); (2) the mesohaline Mid Bay (36% of area); and (3) the polyhaline Lower Bay (53% of area). A distinct regional trend in NEM was observed along this salinity gradient, with net here(atrophy (NEM = 87 g C m-2 yr-1) in the Upper Bay, balanced metabolism in the Mid Bay and net autotrophy (NEM = +92 g C m-2 yr-1) in the Lower Bay. As a consequence of overall net autotrophy, the ratio of dissolved inorganic nitrogen (DIN) to total organic nitrogen (TON) changed from DIN:TON = 5.1 for riverine inputs to DIN:TON = 0.04 for water exported to the ocean. A striking feature of this organic C mass-balance was the relative dominance of biologically mediated metabolic fluxes compared to physical transport fluxes. The overall ratio of physical TOC inputs (1) to biotic primary production (P) was 0.08 for the whole estuary, but varied dramatically from 2.3 in the Upper Bay to 0.03 in the Mid and Lower Bay regions. Similarly, ecosystem respiration was some 6-fold higher than the sum of all physical carbon sinks. This general negative correspondence between I:P ratio and NEM, which occurred among Bay regions, was also evident in data available for organic C fluxes in other coastal ecosystems. An inverse relationship between NEM and P, postulated in a previous study, did not apply to Chesapeake Bay, and closer examination of available data revealed the importance of the loading ratio of DIN:TOC as a key control on coastal NEM. It is proposed here that the general global trend of coastal eutrophication will lead to increasing values of NEM in estuaries worldwide. The management implications of this trend are complex, involving both increased potential fisheries harvest and decreased demersal habitat.
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2004-03-26
CAPE CANAVERAL, Fla. -- This aerial photo shows the expanse of the Launch Complex 39 Area, bordered at the top by the Atlantic and a cloud-filled sky. At center right, towering above the surrounding sites, is the Vehicle Assembly Building. To the left is the Orbiter Processing Facility's Bay 3. In the foreground are OPF Bays 1 and 2. The two-lane crawlerway stretches from the VAB toward the coast, site of Launch Pad 39A, closest, and Launch Pad 39B, far left. Between the VAB and the ocean sprawl the Banana Creek and the Banana River. Photo credit: NASA
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2010-10-16
VANDENBERG AIR FORCE BASE, Calif. – The first, second and third stages of the Taurus XL rocket come together in the east high bay of Building 1555 at Vandenberg Air Force Base in California. In the west high bay, left, is the stage 0 motor. The rocket and NASA's Glory satellite are being prepared for a launch to low Earth orbit from Vandenberg's Space Launch Complex 576-E. Once Glory reaches orbit, it will collect data on the properties of aerosols and black carbon. It also will help scientists understand how the sun's irradiance affects Earth's climate. Photo credit: NASA/Randy Beaudoin, VAFB
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Bennett, Vanessa C. C.; Mulligan, Ryan P.; Hapke, Cheryl J.
2018-01-01
Hurricane Sandy was a large and intense storm with high winds that caused total water levels from combined tides and storm surge to reach 4.0 m in the Atlantic Ocean and 2.5 m in Great South Bay (GSB), a back-barrier bay between Fire Island and Long Island, New York. In this study the impact of the hurricane winds and waves are examined in order to understand the flow of ocean water into the back-barrier bay and water level variations within the bay. To accomplish this goal, a high resolution hurricane wind field is used to drive the coupled Delft3D-SWAN hydrodynamic and wave models over a series of grids with the finest resolution in GSB. The processes that control water levels in the back-barrier bay are investigated by comparing the results of four cases that include: (i) tides only; (ii) tides, winds and waves with no overwash over Fire Island allowed; (iii) tides, winds, waves and limited overwash at the east end of the island; (iv) tides, winds, waves and extensive overwash along the island. The results indicate that strong local wind-driven storm surge along the bay axis had the largest influence on the total water level fluctuations during the hurricane. However, the simulations allowing for overwash have higher correlation with water level observations in GSB and suggest that island overwash provided a significant contribution of ocean water to eastern GSB during the storm. The computations indicate that overwash of 7500–10,000 m3s−1 was approximately the same as the inflow from the ocean through the major existing inlet. Overall, the model results indicate the complex variability in total water levels driven by tides, ocean storm surge, surge from local winds, and overwash that had a significant impact on the circulation in Great South Bay during Hurricane Sandy.
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NASA Astrophysics Data System (ADS)
Bennett, Vanessa C. C.; Mulligan, Ryan P.; Hapke, Cheryl J.
2018-06-01
Hurricane Sandy was a large and intense storm with high winds that caused total water levels from combined tides and storm surge to reach 4.0 m in the Atlantic Ocean and 2.5 m in Great South Bay (GSB), a back-barrier bay between Fire Island and Long Island, New York. In this study the impact of the hurricane winds and waves are examined in order to understand the flow of ocean water into the back-barrier bay and water level variations within the bay. To accomplish this goal, a high resolution hurricane wind field is used to drive the coupled Delft3D-SWAN hydrodynamic and wave models over a series of grids with the finest resolution in GSB. The processes that control water levels in the back-barrier bay are investigated by comparing the results of four cases that include: (i) tides only; (ii) tides, winds and waves with no overwash over Fire Island allowed; (iii) tides, winds, waves and limited overwash at the east end of the island; (iv) tides, winds, waves and extensive overwash along the island. The results indicate that strong local wind-driven storm surge along the bay axis had the largest influence on the total water level fluctuations during the hurricane. However, the simulations allowing for overwash have higher correlation with water level observations in GSB and suggest that island overwash provided a significant contribution of ocean water to eastern GSB during the storm. The computations indicate that overwash of 7500-10,000 m3s-1 was approximately the same as the inflow from the ocean through the major existing inlet. Overall, the model results indicate the complex variability in total water levels driven by tides, ocean storm surge, surge from local winds, and overwash that had a significant impact on the circulation in Great South Bay during Hurricane Sandy.
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Bathymetry, substrate and circulation in Westcott Bay, San Juan Islands, Washington
Grossman, Eric E.; Stevens, Andrew W.; Curran, Chris; Smith, Collin; Schwartz, Andrew
2007-01-01
Nearshore bathymetry, substrate type, and circulation patterns in Westcott Bay, San Juan Islands, Washington, were mapped using two acoustic sonar systems, video and direct sampling of seafloor sediments. The goal of the project was to characterize nearshore habitat and conditions influencing eelgrass (Z. marina) where extensive loss has occurred since 1995. A principal hypothesis for the loss of eelgrass is a recent decrease in light availability for eelgrass growth due to increase in turbidity associated with either an increase in fine sedimentation or biological productivity within the bay. To explore sources for this fine sediment and turbidity, a dual-frequency Biosonics sonar operating at 200 and 430 kHz was used to map seafloor depth, morphology and vegetation along 69 linear kilometers of the bay. The higher frequency 430 kHz system also provided information on particulate concentrations in the water column. A boat-mounted 600 kHz RDI Acoustic Doppler Current Profiler (ADCP) was used to map current velocity and direction and water column backscatter intensity along another 29 km, with select measurements made to characterize variations in circulation with tides. An underwater video camera was deployed to ground-truth acoustic data. Seventy one sediment samples were collected to quantify sediment grain size distributions across Westcott Bay. Sediment samples were analyzed for grain size at the Western Coastal and Marine Geology Team sediment laboratory in Menlo Park, Calif. These data reveal that the seafloor near the entrance to Westcott Bay is rocky with a complex morphology and covered with dense and diverse benthic vegetation. Current velocities were also measured to be highest at the entrance and along a deep channel extending 1 km into the bay. The substrate is increasingly comprised of finer sediments with distance into Westcott Bay where current velocities are lower. This report describes the data collected and preliminary findings of USGS Cruise B-6-07-PS conducted between May 31, 2007 and June 5, 2007.
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Sedimentary framework of Penobscot Bay, Maine
Knebel, Harley J.; Scanlon, Kathryn M.
1985-01-01
Analyses of seismic-reflection profiles, along with previously collected sediment samples and geologic information from surrounding coastal areas, outline the characteristics, distribution, and history of the strata that accumulated within Penobscot Bay, Maine, during the complex period of glaciation, crustal movement, and sea-level change since late Wisconsinan time. Sediments that overlie the rugged, glacially eroded surface of Paleozoic bedrock range in thickness from near zero to more than 50 m and consist of four distinct units.Massive to partly stratified, coarse-grained drift forms thin (< 15 m) isolated patches along the walls and floors of bedrock troughs and constitutes a thick (up to 30 m), hummocky end moraine in the central part of the bay. The drift was deposited by the last ice sheet between 12,700 and 13,500 years ago during deglaciation and coastal submergence (due to crustal depression).Well-stratified, fine-grained glaciomarine deposits are concentrated in bedrock depressions beneath the main passages of the bay. During the period of ice retreat and marine submergence, these sediments settled to the sea floor, draped the irregular underlying surface of bedrock or drift, and accumulated without disturbance by physical or biologic processes.Heterogeneous fluvial deposits fill ancestral channels of the Penobscot River beneath the head of the bay. The channels were incised during a −40 m postglacial low stand of sea level (due to crustal rebound) and later were filled as base level was increased during Holocene time.Muddy marine sediments, which are homogeneous to weakly stratified and rich in organic matter, blanket older deposits within bathymetric depressions in the middle and lower reaches of the bay and cover a pronounced, gently dipping, erosional unconformity in the upper reach. These sediments were deposited during the Holocene transgression as sea level approached its present position and the bay became deeper.Late Wisconsinan and Holocene sedimentation in Penobscot Bay has smoothed the sea floor, but it has not completely obscured the ice-sculptured bedrock topography.
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Hydrogeologic setting and ground water flow beneath a section of Indian River Bay, Delaware
Krantz, David E.; Manheim, Frank T.; Bratton, John F.; Phelan, Daniel J.
2004-01-01
The small bays along the Atlantic coast of the Delmarva Peninsula (Delaware, Maryland, and Virginia) are a valuable natural resource, and an asset for commerce and recreation. These coastal bays also are vulnerable to eutrophication from the input of excess nutrients derived from agriculture and other human activities in the watersheds. Ground water discharge may be an appreciable source of fresh water and a transport pathway for nutrients entering the bays. This paper presents results from an investigation of the physical properties of the surficial aquifer and the processes associated with ground water flow beneath Indian River Bay, Delaware. A key aspect of the project was the deployment of a new technology, streaming horizontal resistivity, to map the subsurface distribution of fresh and saline ground water beneath the bay. The resistivity profiles showed complex patterns of ground water flow, modes of mixing, and submarine ground water discharge. Cores, gamma and electromagnetic-induction logs, and in situ ground water samples collected during a coring operation in Indian River Bay verified the interpretation of the resistivity profiles. The shore-parallel resistivity lines show subsurface zones of fresh ground water alternating with zones dominated by the flow of salt water from the estuary down into the aquifer. Advective flow produces plumes of fresh ground water 400 to 600 m wide and 20 m thick that may extend more than 1 km beneath the estuary. Zones of dispersive mixing between fresh and saline ground water develop on the upper, lower, and lateral boundaries of the the plume. the plumes generally underlie small incised valleys that can be traced landward to stream draining the upland. The incised valleys are filled with 1 to 2 m of silt and peat that act as a semiconfining layer to restrict the downward flow of salt water from the estuary. Active circulation of both the fresh and saline ground water masses beneath the bay is inferred from the geophysical results and supported by geochemical data.
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14th Annual Expeditionary Warfare Conference
2009-11-19
Untitled Document 2009expedition.html[5/12/2016 8:33:22 AM] 14th ANNUAL EXPEDITIONARY WARFARE CONFERENCE “Expeditionary Warfare in a Complex Joint...WWW.NDIA.ORG/MEETINGS/0700 “Expeditionary Warfare in a Complex Joint Operating Environment” BAY POINT MARRIOTT HOTEL, PANAMA CITY, FL...Focus: The purpose of the Quadrennial Defense Review (QDR) is to determine the nation’s defense strategy and establish a defense program for
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NASA Astrophysics Data System (ADS)
Saleh, R.
2017-12-01
For a challenge as complex and far-reaching as sea level rise and improving shoreline resiliency, strong partnerships between scientists, elected officials, decision-makers, and the general public are the only way that effective solutions can be developed. The San Francisco Bay, like many similar sheltered water coastal environments (for example, Galveston Bay, Tampa Bay, or Venetian Lagoon) offers a unique opportunity for multiple jurisdictions to collaborate to address sea level rise on a regional basis. For the San Francisco Bay, significant scientific progress has been made in building a real-time simulation model for riverine and Bay hydrodynamics. Other major scientific initiatives, such as morphology mapping, shoreline mapping, and a sediment budget are also underway. In 2014, leaders from the Bay Area science, engineering, planning, policy, elected, and regulatory communities representing jurisdictions around the Bay joined together to address sea level rise. The group includes people from local, regional, state, and federal agencies and organizations. Together, CHARG (Coastal Hazards Adaptation Resiliency Group) established a collective vision and approach to implementing regional solutions. Decision-makers within many Bay Area jurisdictions are motivated to show demonstrable progress toward addressing sea level rise. However, the cost to implement shoreline resiliency solutions will be very large, and must be founded on strong science.CHARG is now tackling several key technical challenges. One is to develop science-based guidelines for local jurisdictions to determine when a project is local, sub-regional, or regional. Concurrently, several organizations are planning or implementing pilot shoreline resiliency projects and other programs. Many creative regional solutions are possible in a sheltered water environment that simply would not be feasible along the open coast. By definition, these solutions cannot be undertaken by one entity alone. Large-scale regional solutions are only possible through the hard work and collaboration of many. This paper will offer insights into the process of collaboration, initiated by the scientific and engineering communities, to influence and help direct major decisions about shoreline resiliency.
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Mercury distribution and bioaccumulation in a temperate estuary: Masan Bay, Korea
NASA Astrophysics Data System (ADS)
Noh, S.; Kim, E.; Kundu, S. R.; Lee, B.; Han, S.
2012-12-01
Masan Bay is a semi-closed and temperate estuary located on the southeastern coast of Korea. Since it is surrounded by highly populated cities (Masan, Changwon, and Jinhae) and large industrial complexes (petrochemical, electrical, plastic, and metal industries), Masan Bay is contaminated with PCBs and PBDEs, as well as heavy metals. In the current study, we investigated the distribution and sources of Hg and methylmercury (MeHg) in surface water, sediment, and biota from Masan Bay, as well as the impact of sediment organic matter and acid-volatile sulfide on the MeHg fraction over the total Hg, as a proxy of MeHg production potential. Concentrations of Hg in the surface seawater and sediment ranged from 1.2 to 5.1 pM and 0.02 to 0.73 nmol g-1, respectively. The Hg input estimation showed that river water discharge is the prime input source of Hg into the bay. This agrees with the sediment Hg distribution, showing a gradual decrease from the inner bay sites toward the mouth of the bay. Concentrations of MeHg in surface seawater and sediment ranged from 0.02 to 0.41 pM and 0.19 to 1.88 pmol g-1, respectively. The MeHg flux estimation showed that the submarine groundwater discharge is the prime input source of MeHg. Sediment %MeHg was significantly higher in the outer bay sites, with a negative correlation with sediment organic matter content. A similar negative relationship was found for AVS and %MeHg. The solid-phase retention of inorganic Hg as a result of Hg binding by sediment organic matter seems to be a key-process to control Hg methylation potential in Masan Bay sediments. The estimated food web magnification factors Hg and MeHg in benthic organisms were 0.119 and 0.168, respectively, which were similar to those of various coastal marine environments. The food web magnification factors for pelagic organisms were higher than benthic organisms, suggesting that pelagic organisms might be at greater risk of Hg and MeHg accumulation.
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Structure, stratigraphy, and eruption chronology of the Hanauma Bay Tuff Ring, Oahu, Hawaii
NASA Astrophysics Data System (ADS)
Rottas, K. M.; Houghton, B. F.
2010-12-01
The Hanauma Bay-Koko Head Complex is one of several volcanic landforms along the Koko fissure, in southeastern Oahu, that formed during rejuvenated volcanism. The Hanauma Bay region of the complex is comprised of two nested tuff rings. The internal structure of the inner tuff ring is well exposed due to subsequent breaching and wave erosion and is described in detail here for the first time. The inner tuff ring is currently believed to have formed during a single eruption episode. However, field observations, detailed photography, structural mapping in both the vertical and horizontal planes, extensive measurements of bedding attitudes, and stratigraphic analysis suggest that there were a minimum of five distinct intervals of deposition, which also blanketed the deposits of the outer tuff ring with ejecta. These intervals of sedimentation were separated by significant collapses, generating major unconformities that cross the inner wall of the inner ring. The planes of failure are marked by smaller steep-walled channels and gullies, eroded by rainfall-induced runoff and suggesting the failures were each followed by short time breaks with erosion. Within each pyroclastic sequence there are also smaller slump scars and local unconformities. The inner tuff ring was predominately formed by pyroclastic surges, although the beds of Phase 3 are primarily fall deposits. From ballistic trajectories and bedding features, it is apparent that the eruption locus shifted a minimum of two times during tuff ring growth. Ballistic blocks in the final Phase 5 indicate that the Hanauma Bay eruption was contemporaneous with a separate eruption to the north, most likely that of the Kahauloa tuff ring 880 meters away.
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NASA Astrophysics Data System (ADS)
Le, Chengfeng; Hu, Chuanmin; English, David; Cannizzaro, Jennifer; Chen, Zhiqiang; Kovach, Charles; Anastasiou, Christopher J.; Zhao, Jun; Carder, Kendall L.
2013-01-01
Inherent and apparent optical properties (IOPs and AOPs) of Tampa Bay (Florida, USA) were measured during fourteen cruises between February 1998 and October 2010 to understand how these properties relate to one another and what controls light absorption and diffuse attenuation in this moderately sized (˜1000 km2), shallow estuary (average depth ˜4 m). The IOPs and AOPs included: 1) absorption coefficients of three optically significant constituents: phytoplankton pigments, detrital particles, and colored dissolved organic matter (CDOM); 2) particulate backscattering coefficients; 3) chlorophyll-a concentrations; 4) above-water remote sensing reflectance; 5) downwelling diffuse attenuation coefficients (Kd) at eight wavelengths and photosynthetically active radiation (PAR). Results showed substantial variability in all IOPs and AOPs in both space and time, with most IOPs spanning more than two orders of magnitude and showing strong co-variations. Of all four bay segments, Old Tampa Bay showed unique optical characteristics. During the wet season, the magnitude of blue-green-light absorption was dominated by CDOM, while during the dry season all three constituents contributed significantly. However, the variability in Kd (PAR, 490 nm, 555 nm) was driven mainly by the variability of detrital particles and phytoplankton as opposed to CDOM. This observation explained, at least to first order, why a nutrient reduction management strategy used by the Tampa Bay Estuary Program since the 1990s led to improved water clarity in most of Tampa Bay. The findings of this study provided the optical basis to fine tune existing or develop new algorithms to estimate the various optical water quality parameters from space.
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Hierarchical Naive Bayes for genetic association studies.
Malovini, Alberto; Barbarini, Nicola; Bellazzi, Riccardo; de Michelis, Francesca
2012-01-01
Genome Wide Association Studies represent powerful approaches that aim at disentangling the genetic and molecular mechanisms underlying complex traits. The usual "one-SNP-at-the-time" testing strategy cannot capture the multi-factorial nature of this kind of disorders. We propose a Hierarchical Naïve Bayes classification model for taking into account associations in SNPs data characterized by Linkage Disequilibrium. Validation shows that our model reaches classification performances superior to those obtained by the standard Naïve Bayes classifier for simulated and real datasets. In the Hierarchical Naïve Bayes implemented, the SNPs mapping to the same region of Linkage Disequilibrium are considered as "details" or "replicates" of the locus, each contributing to the overall effect of the region on the phenotype. A latent variable for each block, which models the "population" of correlated SNPs, can be then used to summarize the available information. The classification is thus performed relying on the latent variables conditional probability distributions and on the SNPs data available. The developed methodology has been tested on simulated datasets, each composed by 300 cases, 300 controls and a variable number of SNPs. Our approach has been also applied to two real datasets on the genetic bases of Type 1 Diabetes and Type 2 Diabetes generated by the Wellcome Trust Case Control Consortium. The approach proposed in this paper, called Hierarchical Naïve Bayes, allows dealing with classification of examples for which genetic information of structurally correlated SNPs are available. It improves the Naïve Bayes performances by properly handling the within-loci variability.
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Islands at bay: Rising seas, eroding islands, and waterbird habitat loss in Chesapeake Bay (USA)
Erwin, R.M.; Brinker, D.F.; Watts, B.D.; Costanzo, G.R.; Morton, D.D.
2011-01-01
Like many resources in the Chesapeake Bay region of the U. S., many waterbird nesting populations have suffered over the past three to four decades. In this study, historic information for the entire Bay and recent results from the Tangier Sound region were evaluated to illustrate patterns of island erosion and habitat loss for 19 breeding species of waterbirds. Aerial imagery and field data collected in the nesting season were the primary sources of data. From 1993/1994 to 2007/2008, a group of 15 islands in Tangier Sound, Virginia were reduced by 21% in area, as most of their small dunes and associated vegetation and forest cover were lost to increased washovers. Concurrently, nesting American black ducks (Anas rubripes) declined by 66%, wading birds (herons-egrets) by 51%, gulls by 72%, common terns (Sterna hirundo) by 96% and black skimmers (Rynchops niger) by about 70% in this complex. The declines noted at the larger Bay-wide scale suggest that this study area maybe symptomatic of a systemic limitation of nesting habitat for these species. The island losses noted in the Chesapeake have also been noted in other Atlantic U. S. coastal states. Stabilization and/or restoration of at least some of the rapidly eroding islands at key coastal areas are critical to help sustain waterbird communities. ?? 2010 US Government.
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Modeling Fecal Indicator Bacteria Like Salt in Newport Bay
NASA Astrophysics Data System (ADS)
Ciglar, A. M.; Rippy, M.; Grant, S. B.
2015-12-01
Newport Bay is a harbor and estuary located in Orange County, CA that provides many water sports and recreational activities for millions of southern California residents and tourists. The aim of this study is to quickly assess exceedances of FIB in the Newport Bay which pose a health risk to recreational users. The ability to quickly assess water quality is made possible with an advection-diffusion mass transport model that uses easily measurable parameters such as volumetric flow rate from tributaries. Current FIB assessment methods for Newport Bay take a minimum of 24 hours to evaluate health risk by either culturing for FIB or running a more complex fluid dynamics model. By this time the FIB may have already reached the ocean outlet thus no longer posing a risk in the bay or recreationists may have already come in close contact with contaminated waters. The advection-diffusion model can process and disseminate health risk information within a few hours of flow rate measurements, minimizing time between an FIB exceedance and public awareness about the event. Data used to calibrate and validate the model was collected from January 2006 through February 2007. Salinity data was used for calibration and FIB data was used for validation. Both steady-state and transient conditions were assessed to determine if dry weather patterns can be simplified to the steady-state condition.
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NASA Astrophysics Data System (ADS)
Grigg, R. W.
1995-11-01
The effects of natural and anthropogenic stress need to be separated before coral reef ecosystems can be effectively managed. In this paper, a 25 year case history of coral reefs in an urban embayment (Mamala Bay) off Honolulu, Hawaii is described and differences between natural and man-induced stress are distinguished. Mamala Bay is a 30 km long shallow coastal bay bordering the southern (leeward) shore of Oahu and the city of Honolulu in the Hawaiian Islands. During the last 25 years, this area has been hit by two magnitude 5 hurricane events (winds > 240 km/h) generating waves in excess of 7.5 m. Also during this period, two large sewer outfalls have discharged up to 90 million gallons per day (mgd) or (360 × 106 L/day) of point source pollution into the bay. Initially the discharge was raw sewage, but since 1977 it has received advanced primary treatment. Non-point source run-off from the Honolulu watershed also enters the bay on a daily basis. The results of the study show that discharge of raw sewage had a serious but highly localized impact on shallow (˜10 m) reef corals in the bay prior to 1977. After 1977, when treatment was upgraded to the advanced primary level and outfalls were extended to deep water (> 65 m), impacts to reef corals were no longer significant. No measurable effects of either point or non-point source pollution on coral calcification, growth, species composition, diversity or community structure related to pollution can now be detected. Conversely the effects of hurricane waves in 1982 and 1992 together caused major physical destruction to the reefs. In 1982, average coral cover of well-developed offshore reefs dropped from 60-75% to 5-15%. Only massive species in high relief areas survived. Today, recovery is occurring, and notwithstanding major future disturbance events, long-term biological processes should eventually return the coral ecosystems to a more mature successional stage. This case history illustrates the complex nature of the cumulative effects of natural and anthropogenic stress on coral reefs and the need for a long-term data base before the status of a coral reef can be properly interpreted.
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NASA Astrophysics Data System (ADS)
Fritz-Endres, T.; Dekens, P.; Fehrenbacher, J. S.; Spero, H. J.; Stine, A.
2017-12-01
Paleoceanographic research traditionally focuses on regions where sediment deposition is minimally affected by transport. However, sediment fans near tectonically active regions provide an opportunity to link oceanographic climate to terrestrial processes. Sediment cores recovered during IODP Expedition 354 in the Bay of Bengal include hemipelagic sections that record the history of tectonic uplift and the development of the Indian Monsoon through the last 10 Ma. Although these cores provide a unique opportunity to link marine and terrestrial climate, the complex depositional environment requires that the source of foraminifera is carefully considered before using these proxies to reconstruct oceanographic conditions. Foraminifera in Bengal Fan sediments may have been transported via turbidity currents from the northern Bay of Bengal, where the seasonal variability of SST and SSS is larger compared to the southern Bay of Bengal. We measured single Globigerinoides sacculifer Mg/Ca and δ18O from mudline samples of IODP Site U1454 (8.4°N, 85.5°E, 3721 m water depth) near the modern active channel and Site U1449 (8.4°N, 88.7°E, 3653 m water depth) far from channel activity. We compare these sites to single G. sacculifer from the core-top sample of Site 342KL (20.6°N, 90.1°E, 1256 m water depth) located on the continental shelf. Each foraminifera lives 2-4 weeks and the distribution of 60 to 80 data points reflects the seasonal range of SST and SSS at the location where the foraminifera calcified. Measurements in foraminifera from Site U1449 (away from active channel) are statistically different from the site in the northern Bay of Bengal and more consistent with local conditions. Conversely, foraminifera from the site near the active channel reflect a combined signal of local conditions recorded from the site far from channel activity and those recorded from the continental shelf. This suggests a portion of foraminifera from the active channel site have been transported from the northern Bay of Bengal. Our data show that foraminifera can be used to reconstruct SST and δ18O in this complex depositional environment, but caution must be taken when the down-core lithology indicates turbidites and possible sediment transport
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2011-01-01
Background Molecular marker information is a common source to draw inferences about the relationship between genetic and phenotypic variation. Genetic effects are often modelled as additively acting marker allele effects. The true mode of biological action can, of course, be different from this plain assumption. One possibility to better understand the genetic architecture of complex traits is to include intra-locus (dominance) and inter-locus (epistasis) interaction of alleles as well as the additive genetic effects when fitting a model to a trait. Several Bayesian MCMC approaches exist for the genome-wide estimation of genetic effects with high accuracy of genetic value prediction. Including pairwise interaction for thousands of loci would probably go beyond the scope of such a sampling algorithm because then millions of effects are to be estimated simultaneously leading to months of computation time. Alternative solving strategies are required when epistasis is studied. Methods We extended a fast Bayesian method (fBayesB), which was previously proposed for a purely additive model, to include non-additive effects. The fBayesB approach was used to estimate genetic effects on the basis of simulated datasets. Different scenarios were simulated to study the loss of accuracy of prediction, if epistatic effects were not simulated but modelled and vice versa. Results If 23 QTL were simulated to cause additive and dominance effects, both fBayesB and a conventional MCMC sampler BayesB yielded similar results in terms of accuracy of genetic value prediction and bias of variance component estimation based on a model including additive and dominance effects. Applying fBayesB to data with epistasis, accuracy could be improved by 5% when all pairwise interactions were modelled as well. The accuracy decreased more than 20% if genetic variation was spread over 230 QTL. In this scenario, accuracy based on modelling only additive and dominance effects was generally superior to that of the complex model including epistatic effects. Conclusions This simulation study showed that the fBayesB approach is convenient for genetic value prediction. Jointly estimating additive and non-additive effects (especially dominance) has reasonable impact on the accuracy of prediction and the proportion of genetic variation assigned to the additive genetic source. PMID:21867519
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Virioplankton dynamics are related to eutrophication levels in a tropical urbanized bay
Cabral, Anderson S.; Lessa, Mariana M.; Junger, Pedro C.; Thompson, Fabiano L.; Paranhos, Rodolfo
2017-01-01
Virioplankton are an important and abundant biological component of marine and freshwater ecosystems. Often overlooked, aquatic viruses play an important role in biogeochemical cycles on a global scale, infecting both autotrophic and heterotrophic microbes. Viral diversity, abundance, and viral interactions at different trophic levels in aqueous environments are not well understood. Tropical ecosystems are less frequently studied than temperate ecosystems, but could provide new insights into how physical and chemical variability can shape or force microbial community changes. In this study, we found high viral abundance values in Guanabara Bay relative to other estuaries around the world. Viral abundance was positively correlated with bacterioplankton abundance and chlorophyll a concentrations. Moreover, prokaryotic and viral abundance were positively correlated with eutrophication, especially in surface waters. These results provide novel baseline data on the quantitative distribution of aquatic viruses in tropical estuaries. They also provide new information on a complex and dynamic relationship in which environmental factors influence the abundance of bacterial hosts and consequently their viruses. Guanabara Bay is characterized by spatial and seasonal variations, and the eutrophication process is the most important factor explaining the structuring of virioplankton abundance and distribution in this tropical urbanized bay. PMID:28362842
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Doubly Bayesian Analysis of Confidence in Perceptual Decision-Making.
Aitchison, Laurence; Bang, Dan; Bahrami, Bahador; Latham, Peter E
2015-10-01
Humans stand out from other animals in that they are able to explicitly report on the reliability of their internal operations. This ability, which is known as metacognition, is typically studied by asking people to report their confidence in the correctness of some decision. However, the computations underlying confidence reports remain unclear. In this paper, we present a fully Bayesian method for directly comparing models of confidence. Using a visual two-interval forced-choice task, we tested whether confidence reports reflect heuristic computations (e.g. the magnitude of sensory data) or Bayes optimal ones (i.e. how likely a decision is to be correct given the sensory data). In a standard design in which subjects were first asked to make a decision, and only then gave their confidence, subjects were mostly Bayes optimal. In contrast, in a less-commonly used design in which subjects indicated their confidence and decision simultaneously, they were roughly equally likely to use the Bayes optimal strategy or to use a heuristic but suboptimal strategy. Our results suggest that, while people's confidence reports can reflect Bayes optimal computations, even a small unusual twist or additional element of complexity can prevent optimality.
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Bowhead whale springtime song off West Greenland.
Stafford, Kathleen M; Moore, Sue E; Laidre, Kristin L; Heide-Jørgensen, M P
2008-11-01
Three songs were recorded from bowhead whales (Balaena mysticetus) in Disko Bay, West Greenland, during 59 h of recordings via sonobuoys deployed on seven days between 5 and 14 April 2007. Song elements were defined by units following the protocol of previous description of bowhead whale song. The two most prominent songs were loud, complex, and repeated in long bouts on multiple recording days while the third song was much simpler and recorded on only one day. Bowhead whale simple calls and faint song elements were also recorded using digital audio tape recorders and a dipping hydrophone deployed from the sea ice approximately 100-150 km southwest of Disko Bay on three separate days suggesting that song is also produced in the central portion of Baffin Bay in winter. Songs recorded in Disko Bay are from an area where approximately 85% of the whales have been determined to be adult females. Although it is not known which sex was singing, we speculate that, as in humpback whales (Megaptera novaeangliae), male bowhead whales may sing to mediate sexual competition or mate selection behaviors. This is the first detailed description of springtime songs for bowhead whales in the eastern Arctic.
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NASA Astrophysics Data System (ADS)
Kim, Tae-Wook; Kim, Dongseon; Baek, Seung Ho; Kim, Young Ok
2015-04-01
We investigated seawater nutrient and carbon parameters in Kwangyang Bay, South Korea, which has been exposed to significant human influences, in each core month of four seasons for between 2010 and 2012. The survey data were analyzed using multivariate statistics analysis (cluster and factor analysis). As a result, we found that the Seomjin River (the fifth largest river in South Korea) and biological activity, including phytoplankton photosynthesis and bacterial decomposition, were the main factors determining the overall water quality of the bay. However, the impacts of these factors varied both spatially and seasonally, because the factors were linked with the geographical environments and seasonal variations in freshwater discharge. In particular, the Seomjin River was primarily responsible for nitrate, silicate, total alkalinity, and dissolved inorganic carbon, and exhibited a significant impact in the summer. During the past 10 years, nutrient loads from the river and industrial complexes to the bay have decreased. The impacts of this decrease are visible in the phosphate concentration, which has fallen to a third of its initial value. We also examined the potential role of atmospheric nitrogen deposition in nitrogen cycling in the study area.
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Deshpande, Ashok D; Dockum, Bruce W
2013-12-15
Spatial trends of polybrominated diphenyl ether (PBDE) congeners were examined by using high resolution gas chromatography-low resolution electron impact mass spectrometry (GC-EIMS) in 414 samples of young-of-the-year (YOY) bluefish (Pomatomus saltatrix) collected from a total of 29 nursery habitats along the US Atlantic coastline from Massachusetts to Florida. Of the 26 target PBDE congeners, BDE-47 (4 Br), BDE-100 (5 Br), BDE-49 (4 Br), BDE-99 (5 Br), and BDE-154 (6 Br) were the five most frequently detected congeners in the order of decreasing importance. The sum of the concentrations of five major PBDE congeners, referred to as ΣPBDEs, varied between estuaries and also among samples from a given estuary. ΣPBDEs were lowest in YOY bluefish from Vineyard Sound, Nantucket Sound, Great Bay, Delaware Bay, Lynnhaven Bay, Cape Lookout, and Crescent Beach, with maximum ΣPBDE concentrations below 10 ng/g wet weight. ΣPBDEs in three bluefish samples from Stamford Harbor were detected at relatively high to unusually high concentrations of 69.1, 205, and 561 ng/g wet weight. ΣPBDE values for other Stamford Harbor bluefish were generally low. Highest PBDE concentrations were detected in the vicinity of industrial and urban locations within the New York-New Jersey metropolitan complex. Among them, bluefish from Newark Bay were generally the most contaminated with an average ΣPBDE value of 56.6 ± 30.8 ng/g wet weight. ΣPBDEs in bluefish from Newark Bay were numerically greater than ΣPBDEs in bluefish from all locations, however these differences were not statistically significant. Modest to good correlations between ΣPBDEs and lipids were observed for YOY bluefish from Buzzards Bay, Upper New Bedford Harbor, Lower New Bedford Harbor, Outer New Bedford Harbor, Providence Harbor, Housatonic River, Norwalk Harbor, Little Neck Bay, Newark Bay, Sandy Hook Bay, Great Bay, Delaware Bay, Patuxent River and Crescent Beach. Poor correlations between ΣPBDE and lipids were observed for bluefish from other estuaries. ΣPBDEs were not always correlated with fish length or weight. ΣPBDEs in YOY bluefish along the US Atlantic coastline modestly paralleled ΣPBDEs in mussels and oysters, from not exact but geographically loosely similar locations, reported in the NOAA Mussel Watch Program. A number of researchers who used the high resolution mass spectrometry reported additional PBDE congeners. Although PBDE congeners we report do appear to be the prominent congeners in these studies, it is likely that the comparisons will be skewed in certain instances.
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Usability and Accessibility of eBay by Screen Reader
NASA Astrophysics Data System (ADS)
Buzzi, Maria Claudia; Buzzi, Marina; Leporini, Barbara; Akhter, Fahim
The evolution of Information and Communication Technology and the rapid growth of the Internet have fuelled a great diffusion of eCommerce websites. Usually these sites have complex layouts crowded with active elements, and thus are difficult to navigate via screen reader. Interactive environments should be properly designed and delivered to everyone, including the blind, who usually use screen readers to interact with their computers. In this paper we investigate the interaction of blind users with eBay, a popular eCommerce website, and discuss how using the W3C Accessible Rich Internet Applications (WAI-ARIA) suite could improve the user experience when navigating via screen reader.
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2010-10-16
VANDENBERG AIR FORCE BASE, Calif. – The stage 0 motor, left, and the interstage associated with Stage 1 of the Taurus XL rocket are ready for more processing in the west high bay of Building 1555 at Vandenberg Air Force Base in California. In the east high bay, right, are the first, second and third stages. The rocket and NASA's Glory satellite are being prepared for a launch to low Earth orbit from Vandenberg's Space Launch Complex 576-E. Once Glory reaches orbit, it will collect data on the properties of aerosols and black carbon. It also will help scientists understand how the sun's irradiance affects Earth's climate. Photo credit: NASA/Randy Beaudoin, VAFB
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-09-17
... guarantee that we will be able to do so. Dated: August 29, 2012. J. Paul Loether, Chief, National Register... Brown County Christ Episcopal Church Complex, 425 Cherry St., Green Bay, 12000852 A request for removal...
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SEASONAL AND LONGITUDINAL HOMOGENEITY OF SUSPENDED PARTICLES IN SAN FRANCISCO BAY, CA
Coastal environments are particularly complex due to variations in geology and upstream watersheds, and are subject to dynamic spatial and temporal changes. Their diverse characteristics result in wide variations in response to environmental stressors such as nutrient over-enrich...
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NASA Astrophysics Data System (ADS)
Bailey, R.
2012-12-01
The San Francisco Bay Area is underlain in numerous locales by rocks of the Franciscan Formation, a significant number of which contain amphibole minerals which may occur in a fibrous or asbestiform habit. Such rocks include altered mafic volcanic rocks, serpentine complexes and high pressure metamorphic rocks (e.g. green schist, blue schist, amphibolite, eclogite, etc.). Although it is commonly known that actinolite/tremolite may occur within these rock bodies, it is also true that all of the other "regulated" amphiboles (riebeckite (crocidolite), amosite (grunerite) and anthophyllite, have been identified as well. In addition, a considerable number of other "non-regulated" amphiboles with a fibrous or asbestiform habit have been identified including: glaucophane, winchite, richterite, "Libby amphibole", hornblende, barroisite, cummingtonite and others. Extensive solid solution exists between many of these amphiboles which can make definitive identification difficult. Also, the possibility of complex pressure-temperature paths for these rocks means a single amphibole fiber/crystal can exhibit zonation of, and/or intergrowths between, multiple amphibole phases. It is important that regulators and laboratories are aware of the potential presence of these amphibole minerals, and possibly others, in rock and soil found in the San Francisco Bay Area and that they are not automatically discarded from asbestos fiber counts when they are observed. Criteria for identifying the amphiboles discussed above will be presented.
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NASA Astrophysics Data System (ADS)
Cifelli, R.; Chen, H.; Chandrasekar, V.
2017-12-01
A recent study by the State of California's Department of Water Resources has emphasized that the San Francisco Bay Area is at risk of catastrophic flooding. Therefore, accurate quantitative precipitation estimation (QPE) and forecast (QPF) are critical for protecting life and property in this region. Compared to rain gauge and meteorological satellite, ground based radar has shown great advantages for high-resolution precipitation observations in both space and time domain. In addition, the polarization diversity shows great potential to characterize precipitation microphysics through identification of different hydrometeor types and their size and shape information. Currently, all the radars comprising the U.S. National Weather Service (NWS) Weather Surveillance Radar-1988 Doppler (WSR-88D) network are operating in dual-polarization mode. Enhancement of QPE is one of the main considerations of the dual-polarization upgrade. The San Francisco Bay Area is covered by two S-band WSR-88D radars, namely, KMUX and KDAX. However, in complex terrain like the Bay Area, it is still challenging to obtain an optimal rainfall algorithm for a given set of dual-polarization measurements. In addition, the accuracy of rain rate estimates is contingent on additional factors such as bright band contamination, vertical profile of reflectivity (VPR) correction, and partial beam blockages. This presentation aims to improve radar QPE for the Bay area using advanced dual-polarization rainfall methodologies. The benefit brought by the dual-polarization upgrade of operational radar network is assessed. In addition, a pilot study of gap fill X-band radar performance is conducted in support of regional QPE system development. This paper also presents a detailed comparison between the dual-polarization radar-derived rainfall products with various operational products including the NSSL's Multi-Radar/Multi-Sensor (MRMS) system. Quantitative evaluation of various rainfall products is achieved using rainfall measurements from a validation gauge network, which shows that new dual-polarization methods can produce better QPE, and the X-band radar has excellent potential to augment WSR-88D for rainfall monitoring in this region.
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Hafnium-Based Contrast Agents for X-ray Computed Tomography.
Berger, Markus; Bauser, Marcus; Frenzel, Thomas; Hilger, Christoph Stephan; Jost, Gregor; Lauria, Silvia; Morgenstern, Bernd; Neis, Christian; Pietsch, Hubertus; Sülzle, Detlev; Hegetschweiler, Kaspar
2017-05-15
Heavy-metal-based contrast agents (CAs) offer enhanced X-ray absorption for X-ray computed tomography (CT) compared to the currently used iodinated CAs. We report the discovery of new lanthanide and hafnium azainositol complexes and their optimization with respect to high water solubility and stability. Our efforts culminated in the synthesis of BAY-576, an uncharged hafnium complex with 3:2 stoichiometry and broken complex symmetry. The superior properties of this asymmetrically substituted hafnium CA were demonstrated by a CT angiography study in rabbits that revealed excellent signal contrast enhancement.
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Bradley, Dwight C.; Kusky, Timothy M.; Karl, Susan M.; Haeussler, Peter J.
1997-01-01
Turnagain Arm, just east of Anchorage, provides a readily accessible, world-class cross section through a Mesozoic accretionary wedge. Nearly continuous exposures along the Seward Highway, the Alaska Railroad, and the shoreline of Turnagain Arm display the two main constituent units of the Chugach terrane: the McHugh Complex and Valdez Group. In this paper we describe seven bedrock geology stops along Turnagain Arm, and two others in the Chugach Mountains just to the north (Stops 1-7 and 9), which will be visited as part of the May, 1997 field trip of the Alaska Geological Society. Outcrops along Turnagain Arm have already been described in two excellent guidebook articles (Clark, 1981; Winkler and others 1984), both of which remain as useful and valid today as when first published. Since the early 1980's, studies along Turnagain Arm have addressed radiolarian ages of chert and conodont ages of limestone in the McHugh Complex (Nelson and others, 1986, 1987); geochemistry of basalt in the McHugh Complex (Nelson and Blome, 1991); post-accretion brittle faulting (Bradley and Kusky, 1990; Kusky and others, 1997); and the age and tectonic setting of gold mineralization (Haeussler and others, 1995). Highlights of these newer findings will described both in the text below, and in the stop descriptions.Superb exposures along the southeastern shore of Kachemak Bay show several other features of the McHugh Complex that are either absent or less convincing along Turnagain Arm. While none of these outcrops can be reached via the main road network, they are still reasonably accessible - all are within an hour by motorboat from Homer, seas permitting. Here, we describe seven outcrops along the shore of Kachemak Bay that we studied between 1989 and 1993 during geologic mapping of the Seldovia 1:250,000- scale quadrangle. These outcrops (Stops 61-67) will not be part of the 1997 itinerary, but are included here tor the benefit of those who may wish to visit them later.
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Ultrabasic breccias in layered intrusions - The Rhum complex
NASA Technical Reports Server (NTRS)
Donaldson, C. H.
1975-01-01
Two breccias in the southwest part of the ultrabasic Rhum complex are considered. Aspects of field relations are discussed along with questions regarding the petrography of the matrix. Attention is given to textures and chemical mineralogy, the mechanism of brecciation, matrix magmas, and the possible implications of the findings. It is concluded that the Harris Bay and Ard Mheall ultrabasic breccias formed by brecciation due to the intrusion of feldspathic peridotite magmas.
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Ackerman, Joshua T.; Eagles-Smith, Collin A.
2009-01-01
The present study evaluated Se bioaccumulation in four waterbird species (n = 206 birds) that breed within San Francisco Bay, California, USA: American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), Forster's terns (Sterna forsteri), and Caspian terns (Hydroprogne caspia). Selenium concentrations were variable and influenced by several factors, including species, region, reproductive stage, age, and sex. Adult Se concentrations (μg/g dry wt) in livers ranged from 3.07 to 48.70 in avocets (geometric mean ± standard error, 7.92 ± 0.64), 2.28 to 41.10 in stilts (5.29 ± 0.38), 3.73 to 14.50 in Forster's terns (7.13 ± 0.38), and 4.77 to 14.40 in Caspian terns (6.73 ± 0.78). Avocets had higher Se concentrations in the North Bay compared to the South Bay, whereas stilt Se concentrations were similar between these regions and Forster's terns had lower Se concentrations in the North Bay compared to the South Bay. Female avocets had higher Se concentrations than male avocets, but this was not the case for stilts and Forster's terns. Of the factors assessed, reproductive stage had the most consistent effect among species. Prebreeding birds tended to have higher liver Se concentrations than breeding birds, but this trend was statistically significant only for Forster's terns. Forster's tern chicks had lower Se concentrations than Forster's tern adults, whereas avocet and stilt adults and chicks were similar. Additionally, body condition was negatively related to liver Se concentrations in Forster's tern adults but not in avocet, stilt, or Caspian tern adults and chicks. These variable results illustrate the complexity of Se bioaccumulation and highlight the need to sample multiple species and examine several factors to assess the impact of Se on wildlife.
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River-Lake Mixing, Eutrophication, and Hypoxia in Green Bay, Lake Michigan
NASA Astrophysics Data System (ADS)
Klump, J. V.; LaBuhn, S.
2014-12-01
Despite being a freshwater system, Green Bay in Lake Michigan, has many estuarine-like characteristics, including water mass exchange and the mixing between riverine inflow and the open lake. The bay has experienced excessive nutrient loading for decades resulting in hyper-eutrophic conditions and extensive algal blooms. Combined with a restricted, estuarine like circulation, this has resulted in the reoccurrence of late summer "dead zones" and wide spread bottom water oxygen concentrations below water quality standards. The onset of hypoxia is clearly related to thermal stratification which, in Green Bay, arises both from direct atmospheric forcing, i.e. low winds, high air temperatures, and increased solar radiation, and from indirect atmospheric forcing that drives circulation patterns resulting in the southerly incursion of cooler Lake Michigan bottom waters onto highly reducing organic rich sediment deposits. This circulation pattern can re-stratify a well-mixed water column within hours, and can set up stable stratified water column conditions that persist for days to weeks during which time sediment oxygen demand rates are sufficient to completely deplete hypolimnetic oxygen. Modeling hypoxia, therefore, is somewhat more complex than in a system which is driven largely or solely by seasonal thermal fluctuations. Understanding both the general circulation and the onset and duration of stratification in the bay are essential to determining the potential for hypoxic conditions to improve or worsen, particularly in the face of climate change projections of warmer conditions, less ice cover, and an earlier summer. Using D and O-18 isotopes in water, Rn-222, and dissolved methane as tracers we examine the relationship between river/lake mixing, transport rates and oxygen depletion in an attempt to verify the spatial and temporal scales of hypoxia in the bay, and estimate the potential impact of future climate change projections.
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NASA Astrophysics Data System (ADS)
Tolar, B. B.; Reji, L.; Smith, J. M.; Chavez, F.; Francis, C.
2016-12-01
Thaumarchaeaota are among the most abundant microorganisms on the planet, and are significant players in the global nitrogen cycle. All cultivated members of the phylum are capable of performing the first and rate-limiting step of nitrification - the aerobic oxidation of ammonia to nitrite. In marine environments, ammonia-oxidizing archaea (AOA) have been found to greatly outnumber their bacterial counterparts. However, much about their ecology remains largely unknown. Monterey Bay, a non-estuarine embayment on the central California coast, is an ideal site for studying the dynamics of natural thaumarchaeal assemblages, given the highly dynamic nature of the Bay waters with seasonal upwelling episodes and the associated steep gradients in environmental variables. In the present study, we examined thaumarchaeal population dynamics in the upper Monterey Bay water column (0-500 m) using multiple molecular markers. Following high-resolution spatiotemporal sampling (i.e., up to 10 depths sampled monthly over a period of 2 years) at two stations in the Bay, we quantified thaumarchaeal functional genes - the ammonia monooxygenase (amoA) gene and its `shallow' and `deep' marine ecotypes, and variants of the marine nitrite reductase (nirK) gene. The abundances of both genes were regressed against environmental variables to gain insights into factors shaping their spatiotemporal dynamics in the Bay. Gene abundances at both stations varied with depth and season, with winter months generally having several orders of magnitude greater abundances. Statistical analyses point to differential controls on the gene abundances, with depth and temperature potentially being the major environmental determinants of thaumarchaeal population size. Our results also highlight the importance of employing multiple marker genes to gain a more highly resolved picture of thaumarchaeal population dynamics in complex environmental systems such as the coastal ocean.
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Cross, V.A.; Bratton, J.F.; Michael, H.A.; Kroeger, K.D.; Green, Adrian; Bergeron, Emile M.
2014-01-01
A geophysical survey to delineate the fresh-saline groundwater interface and associated sub-bottom sedimentary structures beneath Indian River Bay, Delaware, was carried out in April 2010. This included surveying at higher spatial resolution in the vicinity of a study site at Holts Landing, where intensive onshore and offshore studies were subsequently completed. The total length of continuous resistivity profiling (CRP) survey lines was 145 kilometers (km), with 36 km of chirp seismic lines surveyed around the perimeter of the bay. Medium-resolution CRP surveying was performed using a 50-meter streamer in a baywide grid. Results of the surveying and data inversion showed the presence of many buried paleochannels beneath Indian River Bay that generally extended perpendicular from the shoreline in areas of modern tributaries, tidal creeks, and marshes. An especially wide and deep paleochannel system was imaged in the southeastern part of the bay near White Creek. Many paleochannels also had high-resistivity anomalies corresponding to low-salinity groundwater plumes associated with them, likely due to the presence of fine-grained estuarine mud and peats in the channel fills that act as submarine confining units. Where present, these units allow plumes of low-salinity groundwater that was recharged onshore to move beyond the shoreline, creating a complex fresh-saline groundwater interface in the subsurface. The properties of this interface are important considerations in construction of accurate coastal groundwater flow models. These models are required to help predict how nutrient-rich groundwater, recharged in agricultural watersheds such as this one, makes its way into coastal bays and impacts surface-water quality and estuarine ecosystems.
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NASA Astrophysics Data System (ADS)
Higuera-Ruiz, R.; Elorza, J.
2009-04-01
Living Crassostrea gigas oysters of different ages and sizes were collected in three estuaries of Cantabria (Bay of Biscay, Spain): San Vicente de la Barquera Estuary, Santander Bay, and Marismas de Santoña Estuary. The main objective was to determine different shell responses to variable environmental parameters. A shell morphological study, based on three biometric indices, indicates that oysters of Santander Bay have two significant shell anomalies: abnormal thickening of the right valve and loss of vital cavity volume. These shell abnormalities are related with the presence in these waters of the chemical tributyltin. In the other two estuaries, the oysters show no detectable anomalies. Four shell microstructures have been distinguished: Regular Simple Prismatic, Regular Foliated, cone-Complex Cross Foliated, and Chalk. In Santander Bay oysters, the Chalk forms a "root-type" framework, whereas in the other two estuaries it forms a more compact microstructure. It is proposed that exposure to tributyltin has produced this modification. High-spatial-resolution geochemical transects have been carried out on the Regular Foliated microstructure in the umbo region in order to evaluate the distribution of Mg, Sr, and Na. The elements analysed exhibit clear cyclic variations in San Vicente de la Barquera Estuary and Marismas de Santoña Estuary oysters, related with seasonal periods, and characterised by broad maxima during months in which the waters are warmer and have higher salinity. These patterns are buffered in Santander Bay oysters. Our results demonstrate that biometric, microstructural, and high-resolution trace element studies in oyster shells can provide information about contaminants and seasonal variations in the estuarine environment.
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NASA Astrophysics Data System (ADS)
Darbyshire, F. A.; Afonso, J. C.; Porritt, R. W.
2015-12-01
The Paleozoic Hudson Bay intracratonic basin conceals a Paleoproterozoic Himalayan-scale continental collision, the Trans-Hudson Orogen (THO), which marks an important milestone in the assembly of the Canadian Shield. The geometry of the THO is complex due to the double-indentor geometry of the collision between the Archean Superior and Western Churchill cratons. Seismic observations at regional scale show a thick, seismically fast lithospheric keel beneath the entire region; an intriguing feature of recent models is a 'curtain' of slightly lower wavespeeds trending NE-SW beneath the Bay, which may represent the remnants of more juvenile material trapped between the two Archean continental cores. The seismic models alone, however, cannot constrain the nature of this anomaly. We investigate the thermal and compositional structure of the Hudson Bay lithosphere using a multi-observable probabilistic inversion technique. This joint inversion uses Rayleigh wave phase velocity data from teleseismic earthquakes and ambient noise, geoid anomalies, surface elevation and heat flow to construct a pseudo-3D model of the crust and upper mantle. Initially a wide range of possible mantle compositions is permitted, and tests are carried out to ascertain whether the lithosphere is stratified with depth. Across the entire Hudson Bay region, low temperatures and a high degree of chemical depletion characterise the mantle lithosphere. Temperature anomalies within the lithosphere are modest, as may be expected from a tectonically-stable region. The base of the thermal lithosphere lies at depths of >250 km, reaching to ~300 km depth in the centre of the Bay. Lithospheric stratification, with a more-depleted upper layer, is best able to explain the geophysical data sets and surface observables. Some regions, where intermediate-period phase velocities are high, require stronger mid-lithospheric depletion. In addition, a narrow region of less-depleted material extends NE-SW across the Bay, likely associated with the trace of the THO collision and the entrapment of juvenile material between the highly-depleted Archean cores.
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A Creek to Bay Biological Assessment in Oakland, California
NASA Astrophysics Data System (ADS)
Ahumada, E.; Ramirez, N.; Lopez, A.; Avila, M.; Ramirez, J.; Arroyo, D.; Bracho, H.; Casanova, A.; Pierson, E.
2011-12-01
In 2007, the Surface Water Ambient Monitoring Program (SWAMP) assessed the impact of trash on water quality in the Peralta Creek which is located in the Fruitvale district of Oakland, CA. This 2011 follow-up study will take further steps in evaluating the physical and biological impacts of pollution and human development on Peralta Creek and in the San Leandro Bay, where the Creek empties into the larger San Francisco Bay estuary. This study will utilize two forms of biological assessment in order to determine the level of water quality and ecosystem health of Peralta Creek and San Leandro Bay in Oakland, California. A Rapid Bioassesment Protocal (RBP) will be used as the method of biological assessment for Peralta Creek. RBP uses a biotic index of benthic macroinvertebrates to provide a measure of a water body's health. Larval trematodes found in two mud snails (Ilynassa obsoleta and Cerithidea californica) will be used to evaluate the health of the San Leandro Bay. Due to the complex life cycle of trematodes, the measure of trematode diversity and richness in host species serves as an indicator of estuarine health (Huspeni 2005). We have completed the assessment of one section of Peralta Creek, located at 2465 34th Avenue, Oakland, CA 94601. Abundance results indicate a moderately healthy creek because there were high levels of pollution tolerant benthic macroinvertebrates. The tolerant group of benthic macroinvertebrates includes such organisms as flatworms, leeches, and scuds. This is possibly due to this section of the creek being pumped up to the surface from culverts impacting the macroinvertebrate's life cycle. Another contributing factor to creek health is the amount of organic debris found in the creek, which inhibits the flow and oxygenation of the water, allowing for more pollution tolerant aquatic insects to persist. Further investigation is being conducted to fully assess the Peralta Creek watershed; from the preliminary results one can surmise that runoff from the watershed that leads into the bay may reflect a moderately healthy San Leandro Bay.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Scott, D.E.; Chazel, A.C.; Pechmann, J.H.K.
1993-06-01
The Defense Waste Processing Facility (DWPF) was built on the Savannah River Site (SRS) during the mid-1980`s. The Savannah River Ecology Laboratory (SREL) has completed 14 years of ecological studies related to the construction of the DWPF complex. Prior to construction, the 600-acre site (S-Area) contained a Carolina bay and the headwaters of a stream. Research conducted by the SREL has focused primarily on four questions related to these wetlands: (1) Prior to construction, what fauna and flora were present at the DWPF site and at similar, yet undisturbed, alternative sites? (2) By comparing the Carolina bay at the DWPFmore » site (Sun Bay) with an undisturbed control Carolina bay (Rainbow Bay), what effect is construction having on the organisms that inhabited the DWPF site? (3) By comparing control streams with streams on the periphery of the DWPF site, what effect is construction having on the peripheral streams? (4) How effective have efforts been to lessen the impacts of construction, both with respect to erosion control measures and the construction of ``refuge ponds`` as alternative breeding sites for amphibians that formerly bred at Sun Bay? Through the long-term census-taking of biota at the DWPF site and Rainbow Bay, SREL has begun to evaluate the impact of construction on the biota and the effectiveness of mitigation efforts. Similarly, the effects of erosion from the DWPF site on the water quality of S-Area peripheral streams are being assessed. This research provides supporting data relevant to the National Environmental Policy Act (NEPA) of 1969, the Endangered Species Act of 1973, Executive Orders 11988 (Floodplain Management) and 11990 (Protection of Wetlands), and United States Department of Energy (DOE) Guidelines for Compliance with Floodplain/Wetland Environmental Review Requirements (10 CFR 1022).« less
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Coupling Fluvial and Oceanic Drivers in Flooding Forecasts for San Francisco Bay
NASA Astrophysics Data System (ADS)
Herdman, L.; Kim, J.; Cifelli, R.; Barnard, P.; Erikson, L. H.; Johnson, L. E.; Chandrasekar, V.
2016-12-01
San Francisco Bay is a highly urbanized estuary and the surrounding communities are susceptible to flooding along the bay shoreline and inland rivers and creeks that drain to the Bay. A forecast model that integrates fluvial and oceanic drivers is necessary for predicting flooding in this complex urban environment. This study introduces the state-of-the-art coupling of the USGS Coastal Storm Modeling System (CoSMoS) with the NWS Research Distributed Hydrologic Model (RDHM) for San Francisco Bay. For this application, we utilize Delft3D-FM, a hydrodynamic model based on a flexible mesh grid, to calculate water levels that account for tidal forcing, seasonal water level anomalies, surge and in-Bay generated wind waves from the wind and pressure fields of a NWS forecast model. The tributary discharges from RDHM are dynamic, meteorologically driven allowing for operational use of CoSMoS which has previously relied on statistical estimates of river discharge. The flooding extent is determined by overlaying the resulting maximum water levels onto a recently updated 2-m digital elevation model of the study area which best resolves the extensive levee and tidal marsh systems in the region. The results we present here are focused on the interaction of the Bay and the Napa River watershed. This study demonstrates the interoperability of the CoSMoS and RDHM prediction models. We also use this pilot region to examine storm flooding impacts in a series of storm scenarios that simulate 5-100yr return period events in terms of either coastal or fluvial events. These scenarios demonstrate the wide range of possible flooding outcomes considering rainfall recurrence intervals, soil moisture conditions, storm surge, wind speed, and tides (spring and neap). With a simulated set of over 25 storm scenarios we show how the extent, level, and duration of flooding is dependent on these atmospheric and hydrologic parameters and we also determine a range of likely flood events.
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Hazardous Waste Cleanup: HOVENSA, LLC in Christiansted, U.S. Virgin Islands
The HOVENSA facility (the facility) is located at Limetree Bay, St. Croix, U.S. Virgin Islands. It is a petroleum refinery covering 1,500 acres in what is known as South Industrial Complex, on the south central coast of St. Croix.
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Li, Wei; Joshi, Sunendra R; Hou, Guangjin; Burdige, David J; Sparks, Donald L; Jaisi, Deb P
2015-01-06
Nutrient contamination has been one of the lingering issues in the Chesapeake Bay because the bay restoration is complicated by temporally and seasonally variable nutrient sources and complex interaction between imported and regenerated nutrients. Differential reactivity of sedimentary phosphorus (P) pools in response to imposed biogeochemical conditions can record past sediment history and therefore a detailed sediment P speciation may provide information on P cycling particularly the stability of a P pool and the formation of one pool at the expense of another. This study examined sediment P speciation from three sites in the Chesapeake Bay: (i) a North site in the upstream bay, (ii) a middle site in the central bay dominated by seasonally hypoxic bottom water, and (iii) a South site at the bay-ocean boundary using a combination of sequential P extraction (SEDEX) and spectroscopic techniques, including (31)P NMR, P X-ray absorption near edge structure spectroscopy (XANES), and Fe extended X-ray absorption fine structure (EXAFS). Results from sequential P extraction reveal that sediment P is composed predominantly of ferric Fe-bound P and authigenic P, which was further confirmed by solid-state (31)P NMR, XANES, and EXAFS analyses. Additionally, solution (31)P NMR results show that the sediments from the middle site contain high amounts of organic P such as monoesters and diesters, compared to the other two sites, but that these compounds rapidly decrease with sediment depth indicating remineralized P could have precipitated as authigenic P. Fe EXAFS enabled to identify the changes in Fe mineral composition and P sinks in response to imposed redox condition in the middle site sediments. The presence of lepidocrocite, vermiculite, and Fe smectite in the middle site sediments indicates that some ferric Fe minerals can still be present along with pyrite and vivianite, and that ferric Fe-bound P pool can be a major P sink in anoxic sediments. These results provide improved insights into sediment P dynamics, particularly the rapid remineralization of organic P and the stability of Fe minerals and the ferric Fe-bound P pool in anoxic sediments in the Chesapeake Bay.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Helbig, Linda; Department of Radiation Oncology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden; Koi, Lydia
2014-01-01
Purpose: To study the effects of BAY-84-7296, a novel orally bioavailable inhibitor of mitochondrial complex I and hypoxia-inducible factor 1 (HIF-1) activity, on hypoxia, microenvironment, and radiation response of tumors. Methods and Materials: UT-SCC-5 and UT-SCC-14 human squamous cell carcinomas were transplanted subcutaneously in nude mice. When tumors reached 4 mm in diameter BAY-84-7296 (Bayer Pharma AG) or carrier was daily administered to the animals. At 7 mm tumors were either excised for Western blot and immunohistologic investigations or were irradiated with single doses. After irradiation animals were randomized to receive BAY-84-7296 maintenance or carrier. Local tumor control was evaluatedmore » 150 days after irradiation, and the dose to control 50% of tumors (TCD{sub 50}) was calculated. Results: BAY-84-7296 decreased nuclear HIF-1α expression. Daily administration of inhibitor for approximately 2 weeks resulted in a marked decrease of pimonidazole hypoxic fraction in UT-SCC-5 (0.5% vs 21%, P<.0001) and in UT-SCC-14 (0.3% vs 19%, P<.0001). This decrease was accompanied by a significant increase in fraction of perfused vessels in UT-SCC-14 but not in UT-SCC-5. Bromodeoxyuridine and Ki67 labeling indices were significantly reduced only in UT-SCC-5. No significant changes were observed in vascular area or necrosis. BAY-84-7296 before single-dose irradiation significantly decreased TCD{sub 50}, with an enhancement ratio of 1.37 (95% confidence interval [CI] 1.13-1.72) in UT-SCC-5 and of 1.55 (95% CI 1.26-1.94) in UT-SCC-14. BAY-84-7296 maintenance after irradiation did not further decrease TCD{sub 50}. Conclusions: BAY-84-7296 resulted in a marked decrease in tumor hypoxia and substantially reduced radioresistance of tumor cells with the capacity to cause a local recurrence after irradiation. The data suggest that reduction of cellular hypoxia tolerance by BAY-84-7296 may represent the primary biological mechanism underlying the observed enhancement of radiation response. Whether this mechanism contributes to the improved outcome of fractionated chemoradiation therapy warrants further investigation.« less
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Handley, Lawrence R.; Spear, Kathryn A.; Gibeaut, Jim; Thatcher, Cindy A.
2014-01-01
The Texas coast (Figure 1) consists of complex and diverse ecosystems with a varying precipitation gradient. The northernmost portion of the coast, extending from Sabine Lake to Galveston Bay, is composed of salt, brackish, intermediate, and fresh marshes, with humid flatwoods inland (Moulton and others, 1997). Coastal prairies are found across the entire coast. From Galveston Bay to Corpus Christi Bay, rivers feed into large bays and estuarine ecosystems. Barrier islands and peninsulas exist along the coast from Galveston Bay to the Mexican border. The southernmost portion of the coast is composed of wind-tidal flats and the hypersaline Laguna Madre. The Laguna Madre lacks rivers and has little rainfall and restricted inlet access to the Gulf. Semiarid rangeland and irrigated agricultural land can be found inland.Approximately 6 million people live in Texas’ coastal counties (U.S. Census Bureau, 2010; Texas GLO, 2013). Seventy percent of the state’s industry and commerce occurs within 160.9 km (100 miles) of the coast (Moulton and others, 1997). Texas ports support 1.4 million jobs and generate $6.5 billion in tax revenues (Texas GLO, 2013). Chemical and petroleum production and marine commerce thrive on the Texas coast. Agriculture, grazing, commercial and recreational fishing, and recreation and tourism are strong industries along the coast and in adjacent areas; oil and gas production, agriculture, and tourism are the state’s three largest industries.
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Hydrocode Simulations of the Chesapeake Bay Impact
NASA Technical Reports Server (NTRS)
Collins, G. S.; Melosh, H. J.
2004-01-01
The Chesapeake Bay Impact Crater (CBIC) formed about 35 million years ago (late Eocene), in a shallow marine environment (400-600 m water depth). The crater is complex and developed in a multi-layer, rheologically-variable target that comprised 400-1000 meters of soft, water-saturated sediments overlying crystalline basement. Seismic reflection data illustrates that the Chesapeake Bay crater morphology - often described as an "inverted sombrero" - is similar to other marine-target impact craters. It consists of a approx. 1 - 1.5-km deep, highly disturbed central crater, surrounded by a shallower, less deformed basin. The inner crater has a diameter of approx. 40 km; the edge of the outer basin extends to 85-km diameter. The morphological divide between the inner and outer crater is termed the inner ring or peak ring. Little is known about the nature of the inner ring. Seismic reflection data show that the underlying basement is modestly uplifted; however, it is unclear whether the pristine surface expression of the inner ring was elevated above the floor of the outer crater.
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Dissolved trace elements in a nitrogen-polluted river near to the Liaodong Bay in Northeast China.
Bu, Hongmei; Song, Xianfang; Guo, Fen
2017-01-15
Dissolved trace element concentrations (Ba, Fe, Mn, Si, Sr, and Zn) were investigated in the Haicheng River near to the Liaodong Bay in Northeast China during 2010. Dissolved Ba, Fe, Mn, and Sr showed significant spatial variation, whereas dissolved Fe, Mn, and Zn displayed seasonal variations. Conditions such as water temperature, pH, and dissolved oxygen were found to have an important impact on redox reactions involving dissolved Ba, Fe, and Zn. Dissolved Fe and Mn concentrations were regulated by adsorption or desorption of Fe/Mn oxyhydroxides and the effects of organic carbon complexation on dissolved Ba and Sr were found to be significant. The sources of dissolved trace elements were found to be mainly from domestic sewage, industrial waste, agricultural surface runoff, and natural origin, with estimated seasonal and annual river fluxes established as important inputs of dissolved trace elements from the Haicheng River into the Liaodong Bay or Bohai Sea. Copyright © 2016 Elsevier Ltd. All rights reserved.
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NASA Astrophysics Data System (ADS)
Hams, J. E.; Uttal, L.; Hunter-Thomson, K.; Nachbar, S.
2010-12-01
This presentation highlights the implementation of the NOAA VOICES OF THE BAY education curriculum at a two-year college. The VOICES OF THE BAY curriculum provides students with an understanding of the marine ecology, economy, and culture of fisheries through three interdisciplinary modules that use hands-on activities while meeting a wide range of science, math, social science, and communications standards. In the BALANCE IN THE BAY module, students use critical-thinking skills and apply principles of ecosystem-based management to analyze data, debate and discuss their findings, and make decisions that recognize the complex dynamics associated with maintaining a balance in fisheries. Through role-playing, teamwork, and a little fate, the FROM OCEAN TO TABLE module provides students with an opportunity to get an insider’s view of what it takes to be an active stakeholder in a commercial fishery. In the CAPTURING THE VOICES OF THE BAY module, students research, plan, and conduct personal interviews with citizens of the local fishing community and explore the multiple dimensions of fisheries and how they inter-connect through the lives of those who live and work in the region. The VOICES OF THE BAY modules were introduced into the curriculum at Los Angeles Valley College during the Fall 2009 semester and are currently being used in the introductory Oceanography lecture, introductory Oceanography laboratory, and Environmental Science laboratory courses. Examples of curriculum materials being used (power point presentations, module worksheets and simulated fishing activities) will be presented. In addition, samples of completed student worksheets for the three interdisciplinary modules are provided. Students commented that their overall awareness and knowledge of the issues involved in sustainable fishing and managing fishery resources increased following completion of the VOICES OF THE BAY education curriculum. Students enrolled in the laboratory sections commented that the lab was more enjoyable than the typical lab exercises and the hands-on nature of the activity made the concept of sustainable fishing more real to them. The Office of National Marine Sanctuaries and the Monterey Bay National Marine Sanctuary sponsor professional development workshops to selected faculty to introduce the VOICES OF THE BAY fisheries education curriculum and assist with implementation in the classroom. Classroom materials are also available on the website http://sanctuaries.noaa.gov/education/voicesofthebay.html or by contacting voicesofthebay@noaa.gov.
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145. VIEW OF LIQUID NITROGEN/HELIUM HEAT EXCHANGER IN FUEL CONTROL ...
145. VIEW OF LIQUID NITROGEN/HELIUM HEAT EXCHANGER IN FUEL CONTROL ROOM (215), LSB (BLDG. 751), FROM FUEL APRON WITH BAY DOOR OPEN - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA
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136. VIEW OF LIQUID NITROGEN/HELIUM HEAT EXCHANGER IN LIQUID NITROGEN ...
136. VIEW OF LIQUID NITROGEN/HELIUM HEAT EXCHANGER IN LIQUID NITROGEN CONTROL ROOM (115), LSB (BLDG. 770), FROM FUEL APRON WITH BAY DOOR OPEN - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA
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Summary of oceanographic and water-quality measurements in Barnegat Bay, New Jersey, 2014–15
Suttles, Steven E.; Ganju, Neil K.; Montgomery, Ellyn T.; Dickhudt, Patrick J.; Borden, Jonathan; Brosnahan, Sandra M.; Martini, Marinna A.
2016-09-26
Scientists and technical support staff from the U.S. Geological Survey measured suspended-sediment concentrations, currents, pressure, and water temperature in two tidal creeks, Reedy Creek and Dinner Creek, in Barnegat Bay, New Jersey, from August 11, 2014, to July 10, 2015 as part of the Estuarine Physical Response to Storms project (GS2–2D). The oceanographic and water-quality data quantify suspended-sediment transport in Reedy Creek and Dinner Creek, which are part of a tidal marsh wetland complex in the Edwin B. Forsythe National Wildlife Refuge. All deployed instruments were removed between January 7, 2015, and April 14, 2015, to avoid damage by ice.
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Geologic Map of the Poverty Bay 7.5' quadrangle, King and Pierce counties, Washington
Booth, Derek B.; Waldron, H.H.; Troost, K.G.
2004-01-01
The Poverty Bay quadrangle lies near the center of the region?s intensively developing urban core. Less than 20 km north lies the city of Seattle; downtown Tacoma lies just southwest of the quadrangle. The map area expresses much of the tremendous range of Quaternary environments and deposits found throughout the central Puget Lowland. Much of the ground surface is mantled by a rolling surface of glacial till deposited during the last occupation of the Puget Lowland by a great continental ice sheet about 14,000 years ago. A complex sequence of older unconsolidated sediments extends far below sea level across most of the quadrangle, with no bedrock exposures at all.
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AutoBayes Program Synthesis System System Internals
NASA Technical Reports Server (NTRS)
Schumann, Johann Martin
2011-01-01
This lecture combines the theoretical background of schema based program synthesis with the hands-on study of a powerful, open-source program synthesis system (Auto-Bayes). Schema-based program synthesis is a popular approach toward program synthesis. The lecture will provide an introduction into this topic and discuss how this technology can be used to generate customized algorithms. The synthesis of advanced numerical algorithms requires the availability of a powerful symbolic (algebra) system. Its task is to symbolically solve equations, simplify expressions, or to symbolically calculate derivatives (among others) such that the synthesized algorithms become as efficient as possible. We will discuss the use and importance of the symbolic system for synthesis. Any synthesis system is a large and complex piece of code. In this lecture, we will study Autobayes in detail. AutoBayes has been developed at NASA Ames and has been made open source. It takes a compact statistical specification and generates a customized data analysis algorithm (in C/C++) from it. AutoBayes is written in SWI Prolog and many concepts from rewriting, logic, functional, and symbolic programming. We will discuss the system architecture, the schema libary and the extensive support infra-structure. Practical hands-on experiments and exercises will enable the student to get insight into a realistic program synthesis system and provides knowledge to use, modify, and extend Autobayes.
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Does the cost function matter in Bayes decision rule?
Schlü ter, Ralf; Nussbaum-Thom, Markus; Ney, Hermann
2012-02-01
In many tasks in pattern recognition, such as automatic speech recognition (ASR), optical character recognition (OCR), part-of-speech (POS) tagging, and other string recognition tasks, we are faced with a well-known inconsistency: The Bayes decision rule is usually used to minimize string (symbol sequence) error, whereas, in practice, we want to minimize symbol (word, character, tag, etc.) error. When comparing different recognition systems, we do indeed use symbol error rate as an evaluation measure. The topic of this work is to analyze the relation between string (i.e., 0-1) and symbol error (i.e., metric, integer valued) cost functions in the Bayes decision rule, for which fundamental analytic results are derived. Simple conditions are derived for which the Bayes decision rule with integer-valued metric cost function and with 0-1 cost gives the same decisions or leads to classes with limited cost. The corresponding conditions can be tested with complexity linear in the number of classes. The results obtained do not make any assumption w.r.t. the structure of the underlying distributions or the classification problem. Nevertheless, the general analytic results are analyzed via simulations of string recognition problems with Levenshtein (edit) distance cost function. The results support earlier findings that considerable improvements are to be expected when initial error rates are high.
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NASA Astrophysics Data System (ADS)
Chu, Jiangtao; Yang, Yue
2018-06-01
Bayesian networks (BN) have many advantages over other methods in ecological modelling and have become an increasingly popular modelling tool. However, BN are flawed in regard to building models based on inadequate existing knowledge. To overcome this limitation, we propose a new method that links BN with structural equation modelling (SEM). In this method, SEM is used to improve the model structure for BN. This method was used to simulate coastal phytoplankton dynamics in Bohai Bay. We demonstrate that this hybrid approach minimizes the need for expert elicitation, generates more reasonable structures for BN models and increases the BN model's accuracy and reliability. These results suggest that the inclusion of SEM for testing and verifying the theoretical structure during the initial construction stage improves the effectiveness of BN models, especially for complex eco-environment systems. The results also demonstrate that in Bohai Bay, while phytoplankton biomass has the greatest influence on phytoplankton dynamics, the impact of nutrients on phytoplankton dynamics is larger than the influence of the physical environment in summer. Furthermore, despite the Redfield ratio indicating that phosphorus should be the primary nutrient limiting factor, our results indicate that silicate plays the most important role in regulating phytoplankton dynamics in Bohai Bay.
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Seafloor geology of the Monterey Bay area continental shelf
Eittreim, S.L.; Anima, R.J.; Stevenson, A.J.
2002-01-01
Acoustic swath-mapping of the greater Monterey Bay area continental shelf from Point An??o Nuevo to Point Sur reveals complex patterns of rock outcrops on the shelf, and coarse-sand bodies that occur in distinct depressions on the inner and mid-shelves. Most of the rock outcrops are erosional cuestas of dipping Tertiary rocks that make up the bedrock of the surrounding lands. A mid-shelf mud belt of Holocene sediment buries the Tertiary rocks in a continuous, 6-km-wide zone on the northern Monterey Bay shelf. Rock exposures occur on the inner shelf, near tectonically uplifting highlands, and on the outer shelf, beyond the reach of the mud depositing on the mid-shelf since the Holocene sea-level rise. The sediment-starved shelf off the Monterey Peninsula and south to Point Sur has a very thin cover of Holocene sediment, and bedrock outcrops occur across the whole shelf, with Salinian granite outcrops surrounding the Monterey Peninsula. Coarse-sand deposits occur both bounded within low-relief rippled scour depressions, and in broad sheets in areas like the Sur Platform where fine sediment sources are limited. The greatest concentrations of coarse-sand deposits occur on the southern Monterey Bay shelf and the Sur shelf. ?? 2002 Elsevier Science B.V. All rights reserved.
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Tidal and tidally averaged circulation characteristics of Suisun Bay, California
Smith, Lawrence H.; Cheng, Ralph T.
1987-01-01
Availability of extensive field data permitted realistic calibration and validation of a hydrodynamic model of tidal circulation and salt transport for Suisun Bay, California. Suisun Bay is a partially mixed embayment of northern San Francisco Bay located just seaward of the Sacramento-San Joaquin Delta. The model employs a variant of an alternating direction implicit finite-difference method to solve the hydrodynamic equations and an Eulerian-Lagrangian method to solve the salt transport equation. An upwind formulation of the advective acceleration terms of the momentum equations was employed to avoid oscillations in the tidally averaged velocity field produced by central spatial differencing of these terms. Simulation results of tidal circulation and salt transport demonstrate that tides and the complex bathymetry determine the patterns of tidal velocities and that net changes in the salinity distribution over a few tidal cycles are small despite large changes during each tidal cycle. Computations of tidally averaged circulation suggest that baroclinic and wind effects are important influences on tidally averaged circulation during low freshwater-inflow conditions. Exclusion of baroclinic effects would lead to overestimation of freshwater inflow by several hundred m3/s for a fixed set of model boundary conditions. Likewise, exclusion of wind would cause an underestimation of flux rates between shoals and channels by 70–100%.
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Liao, J. G.; Mcmurry, Timothy; Berg, Arthur
2014-01-01
Empirical Bayes methods have been extensively used for microarray data analysis by modeling the large number of unknown parameters as random effects. Empirical Bayes allows borrowing information across genes and can automatically adjust for multiple testing and selection bias. However, the standard empirical Bayes model can perform poorly if the assumed working prior deviates from the true prior. This paper proposes a new rank-conditioned inference in which the shrinkage and confidence intervals are based on the distribution of the error conditioned on rank of the data. Our approach is in contrast to a Bayesian posterior, which conditions on the data themselves. The new method is almost as efficient as standard Bayesian methods when the working prior is close to the true prior, and it is much more robust when the working prior is not close. In addition, it allows a more accurate (but also more complex) non-parametric estimate of the prior to be easily incorporated, resulting in improved inference. The new method’s prior robustness is demonstrated via simulation experiments. Application to a breast cancer gene expression microarray dataset is presented. Our R package rank.Shrinkage provides a ready-to-use implementation of the proposed methodology. PMID:23934072
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Migration and stopover strategies of individual Dunlin along the Pacific coast of North America
Warnock, N.; Takekawa, John Y.; Bishop, M.A.
2004-01-01
We radio-marked 18 Dunlin, Calidris alpina (L., 1758), at San Francisco Bay, California, and 11 Dunlin at Grays Harbor, Washington, and relocated 90% of them along the 4200 km long coastline from north of San Francisco Bay to the Yukon-Kuskokwim Delta, Alaska. The Copper River Delta, Alaska, was the single most important stopover site, with 79% of the marked birds detected there. Our second most important site was the Willapa Bay and Grays Harbor complex of wetlands in Washington. The mean length of stay past banding sites ranged from 1.0 to 3.8 days. Controlling for date of departure, birds banded at San Francisco Bay had higher rates of travel to the Copper River Delta than those banded at Grays Harbor. The later a bird left a capture site, the faster it traveled to the Copper River Delta. Length of stay at the Copper River Delta was inversely related to arrival date. We did not find any effect of sex on travel rate or length of stay. Combining the results of this study with our previous work on Western Sandpipers, Calidris mauri (Cabanis, 1875), reveals variation of migration strategies used within and among shorebird species along the eastern Pacific Flyway. ?? 2004 NRC.
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A GIS-BASED WETLAND ASESSMENT MODEL FOR PREDICTING AVIAN HABITAT SUITABILITY UNDER UNCERTAINTY
The Farmington Bay region of the Great Salt Lake is fringed with an array of wetland complexes providing critical avian habitat. Land use and hydrological changes resulting from projected urban population increases and combined with the low topographical relief of the lake basin...
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Environmental Assessment of Stone Road Widening at Mission Lake Moody Air Force Base, Georgia
2012-01-01
complex is composed of several broad Carolina bays (1 to 4 miles across) and shallow lakes, interconnected by cypress-black gum swamp (Moody AFB 2008... regeneration (i.e., pine plantations). Where periodic fires have been suppressed, hardwoods such as water oak (Quercus nigra) and sweetgum
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ERIC Educational Resources Information Center
Handelsman, Mitchell M.
2017-01-01
In this article, I describe a recent scandal involving collusion between officials at the American Psychological Association (APA) and the U.S. Department of Defense, which appears to have enabled the torture of detainees at the Guantanamo Bay detention facility. The scandal is a relevant, complex, and engaging case that teachers can use in a…
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Exploring the Complexity of Teacher Professional Identity
ERIC Educational Resources Information Center
Hsieh, Betina Yuan-Cheng
2010-01-01
This dissertation is based on a case study of 8 beginning English teachers who participated in a collaborative inquiry group at an urban, comprehensive, high school in the San Francisco Bay Area. Qualitative data (including audio-transcribed meeting data, individual interview data, and classroom observations) were collected over two school years,…
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MODELING OF THE MISSISSIPPI SOUND AND ADJOINING RIVERS, BAYS, AND SHELF WATERS
The Gulf of Mexico and its coastal watersheds are a complex ecosystem that is receiving negative impacts from human activities both in the Gulf and its watersheds. The Gulf of Mexico Program (GMP), as a multi-agency effort, is working with the Gulf States, citizens, and private ...
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NASA Astrophysics Data System (ADS)
Megías Trujillo, Bárbara; Caballero de Frutos, Isabel; López Comi, Laura; Tejedor Alvarez, Begoña.; Izquierdo González, Alfredo; Gonzales Mejías, Carlos Jose; Alvarez Esteban, Óscar; Mañanes Salinas, Rafael; Comerma, Eric
2010-05-01
Algeciras Bay constitutes a physical environment of special characteristics, due to its bathymetric configuration and geographical location, at the eastern boundary of the Strait of Gibraltar. Hence, the Bay is subject to the complex hydrodynamics of the Strait of Gibraltar, characterized by a mesotidal, semidiurnal regime and the high density-stratification of the water column due to the presence of the upper Atlantic and the lower Mediterranean (more salty and cold) water layers. In addition, this environment is affected by powerful Easterly and Westerly winds episodes. The intense maritime traffic of oil tankers sailing across the Strait and inside the Bay, together with the presence of an oil refinery at its northern coast, imply high risks of oil spilling inside these waters, and unfortunately it has constituted a matter of usual occurrence through the last decades. The above paragraph clearly manifests the necessity of a detailed knowledge on the Bay's hydrodynamics, and the related system of currents, for a correct management and contingency planning in case of oil spilling in this environment. In order to evaluate the range of affectation of oil spills in the Bay's waters and coasts, the OILMAP oil spill model was used, the currents fields being provided by the three-dimensional, nonlinear, finite-differences, sigma-coordinates, UCA 3D hydrodynamic model. Numerical simulations were carried out for a grid domain extended from the western Strait boundary to the Alboran Sea, having a horizontal spatial resolution of 500 m and 50 sigma-levels in the vertical dimension. The system was forced by the tidal constituents M2 (main semidiurnal) and Z0 (constant or zero-frequency), considering three different typical wind conditions: Easterlies, Westerlies and calm (no wind). The most remarkable results from the numerical 3D simulations of Algeciras Bay's hydrodynamics were: a) the occurrence of opposite tidal currents between the upper Atlantic and lower Mediterranean water layers (i.e., there is a phase-lag of about 180° among them); b) the presence of high-frequency perturbations due to the penetration of internal waves; and c) high variability in the vertical profiles of both tidal and residual (mean) currents. All these phenomena contribute to obtain differences between the water-surface currents and their depth-averaged values (as they are provided by most of 2D hydrodynamic models). Resultant currents from the 3D numerical simulations were implemented into the OILMAP model to evaluate the response of a control oil spill inside Algeciras Bay, considering different scenarios. Results were analyzed focusing in the differences between the more realistic surface currents fields given by the UCA 3D model and the depth averaged fields provided by faster 2D schemes, as well as the influence of implementations of wind effects having different complexities. The relative adequacy between the more accurate (but more expensive in computational time) and the faster (but more unrealistic) modeling strategies, especially in cases of emergency and very short decision times, was discussed.
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Logsdon, Benjamin A.; Carty, Cara L.; Reiner, Alexander P.; Dai, James Y.; Kooperberg, Charles
2012-01-01
Motivation: For many complex traits, including height, the majority of variants identified by genome-wide association studies (GWAS) have small effects, leaving a significant proportion of the heritable variation unexplained. Although many penalized multiple regression methodologies have been proposed to increase the power to detect associations for complex genetic architectures, they generally lack mechanisms for false-positive control and diagnostics for model over-fitting. Our methodology is the first penalized multiple regression approach that explicitly controls Type I error rates and provide model over-fitting diagnostics through a novel normally distributed statistic defined for every marker within the GWAS, based on results from a variational Bayes spike regression algorithm. Results: We compare the performance of our method to the lasso and single marker analysis on simulated data and demonstrate that our approach has superior performance in terms of power and Type I error control. In addition, using the Women's Health Initiative (WHI) SNP Health Association Resource (SHARe) GWAS of African-Americans, we show that our method has power to detect additional novel associations with body height. These findings replicate by reaching a stringent cutoff of marginal association in a larger cohort. Availability: An R-package, including an implementation of our variational Bayes spike regression (vBsr) algorithm, is available at http://kooperberg.fhcrc.org/soft.html. Contact: blogsdon@fhcrc.org Supplementary information: Supplementary data are available at Bioinformatics online. PMID:22563072
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Miles, A.K.; Ricca, M.A.
2010-01-01
Decommissioned agricultural salt ponds within south San Francisco Bay, California, are in the process of being converted to habitat for the benefit of wildlife as well as water management needs and recreation. Little is known of baseline levels of contaminants in these ponds, particularly mercury (Hg), which has a well established legacy in the Bay. In this study we described spatial and short-term temporal variations in sediment Hg species concentrations within and among the Alviso and Eden Landing salt ponds in the southern region of San Francisco Bay. We determined total Hg (Hgt) and methylmercury (MeHg) in the top 5 cm of sediment of most ponds in order to establish baseline conditions prior to restoration, sediment Hgt concentrations in a subset of these ponds after commencement of restoration, and variation in MeHg concentrations relative to sediment Hgt, pH, and total Fe concentrations and water depth and salinity in the subset of Alviso ponds. Inter-pond differences were greatest within the Alviso pond complex, where sediment Hgt concentrations averaged (arithmetic mean) 0.74 ??g/g pre and 1.03 ??g/g post-restoration activity compared to 0.11 ??g/g pre and post at Eden Landing ponds. Sediment Hgt levels at Alviso were fairly stable temporally and spatially, whereas MeHg levels were variable relative to restoration activities across time and space. Mean (arithmetic) sediment MeHg concentrations increased (2.58 to 3.03 ng/g) in Alviso and decreased (2.20 to 1.03 ng/g) in Eden Landing restoration ponds during the study. Differences in MeHg levels were related to water depth and pH, but these relationships were not consistent between years or among ponds and were viewed with caution. Factors affecting MeHg levels in these ponds (and in general) are highly complex and require in-depth study to understand.
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Havens, K E; Hauxwell, J; Tyler, A C; Thomas, S; McGlathery, K J; Cebrian, J; Valiela, I; Steinman, A D; Hwang, S J
2001-01-01
The relative biomass of autotrophs (vascular plants, macroalgae, microphytobenthos, phytoplankton) in shallow aquatic ecosystems is thought to be controlled by nutrient inputs and underwater irradiance. Widely accepted conceptual models indicate that this is the case both in marine and freshwater systems. In this paper we examine four case studies and test whether these models generally apply. We also identify other complex interactions among the autotrophs that may influence ecosystem response to cultural eutrophication. The marine case studies focus on macroalgae and its interactions with sediments and vascular plants. The freshwater case studies focus on interactions between phytoplankton, epiphyton, and benthic microalgae. In Waquoit Bay, MA (estuary), controlled experiments documented that blooms of macroalgae were responsible for the loss of eelgrass beds at nutrient-enriched locations. Macroalgae covered eelgrass and reduced irradiance to the extent that the plants could not maintain net growth. In Hog Island Bay, VA (estuary), a dense lawn of macroalgae covered the bottom sediments. There was reduced sediment-water nitrogen exchange when the algae were actively growing and high nitrogen release during algal senescence. In Lakes Brobo (West Africa) and Okeechobee (FL), there were dramatic seasonal changes in the biomass and phosphorus content of planktonic versus attached algae, and these changes were coupled with changes in water level and abiotic turbidity. Deeper water and/or greater turbidity favored dominance by phytoplankton. In Lake Brobo there also was evidence that phytoplankton growth was stimulated following a die-off of vascular plants. The case studies from Waquoit Bay and Lake Okeechobee support conceptual models of succession from vascular plants to benthic algae to phytoplankton along gradients of increasing nutrients and decreasing under-water irradiance. The case studies from Hog Island Bay and Lake Brobo illustrate additional effects (modified sediment-water nutrient fluxes, allelopathy or nutrient release during plant senescence) that could play a role in ecosystem response to nutrient stress.
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A two-dimensional hydrodynamic model of a tidal estuary
Walters, Roy A.; Cheng, Ralph T.
1979-01-01
A finite element model is described which is used in the computation of tidal currents in an estuary. This numerical model is patterned after an existing algorithm and has been carefully tested in rectangular and curve-sided channels with constant and variable depth. One of the common uncertainties in this class of two-dimensional hydrodynamic models is the treatment of the lateral boundary conditions. Special attention is paid specifically to addressing this problem. To maintain continuity within the domain of interest, ‘smooth’ curve-sided elements must be used at all shoreline boundaries. The present model uses triangular, isoparametric elements with quadratic basis functions for the two velocity components and a linear basis function for water surface elevation. An implicit time integration is used and the model is unconditionally stable. The resultant governing equations are nonlinear owing to the advective and the bottom friction terms and are solved iteratively at each time step by the Newton-Raphson method. Model test runs have been made in the southern portion of San Francisco Bay, California (South Bay) as well as in the Bay west of Carquinez Strait. Owing to the complex bathymetry, the hydrodynamic characteristics of the Bay system are dictated by the generally shallow basins which contain deep, relict river channels. Great care must be exercised to ensure that the conservation equations remain locally as well as globally accurate. Simulations have been made over several representative tidal cycles using this finite element model, and the results compare favourably with existing data. In particular, the standing wave in South Bay and the progressive wave in the northern reach are well represented.
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Lin, Chih-Hsien Michelle; Lyubchich, Vyacheslav; Glibert, Patricia M
2018-03-01
The harmful dinoflagellate, Karlodnium veneficum, has been implicated in fish-kill and other toxic, harmful algal bloom (HAB) events in waters worldwide. Blooms of K. veneficum are known to be related to coastal nutrient enrichment but the relationship is complex because this HAB taxon relies not only on dissolved nutrients but also particulate prey, both of which have also changed over time. Here, applying cross-correlations of climate-related physical factors, nutrients and prey, with abundance of K. veneficum over a 10-year (2002-2011) period, a synthesis of the interactive effects of multiple factors on this species was developed for Chesapeake Bay, where blooms of the HAB have been increasing. Significant upward trends in the time series of K. veneficum were observed in the mesohaline stations of the Bay, but not in oligohaline tributary stations. For the mesohaline regions, riverine sources of nutrients with seasonal lags, together with particulate prey with zero lag, explained 15%-46% of the variation in the K. veneficum time series. For the oligohaline regions, nutrients and particulate prey generally showed significant decreasing trends with time, likely a reflection of nutrient reduction efforts. A conceptual model of mid-Bay blooms is presented, in which K. veneficum, derived from the oceanic end member of the Bay, may experience enhanced growth if it encounters prey originating from the tributaries with different patterns of nutrient loading and which are enriched in nitrogen. For all correlation models developed herein, prey abundance was a primary factor in predicting K. veneficum abundance. Copyright © 2018 Elsevier B.V. All rights reserved.
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Zhang, J; Feng, J-Y; Ni, Y-L; Wen, Y-J; Niu, Y; Tamba, C L; Yue, C; Song, Q; Zhang, Y-M
2017-06-01
Multilocus genome-wide association studies (GWAS) have become the state-of-the-art procedure to identify quantitative trait nucleotides (QTNs) associated with complex traits. However, implementation of multilocus model in GWAS is still difficult. In this study, we integrated least angle regression with empirical Bayes to perform multilocus GWAS under polygenic background control. We used an algorithm of model transformation that whitened the covariance matrix of the polygenic matrix K and environmental noise. Markers on one chromosome were included simultaneously in a multilocus model and least angle regression was used to select the most potentially associated single-nucleotide polymorphisms (SNPs), whereas the markers on the other chromosomes were used to calculate kinship matrix as polygenic background control. The selected SNPs in multilocus model were further detected for their association with the trait by empirical Bayes and likelihood ratio test. We herein refer to this method as the pLARmEB (polygenic-background-control-based least angle regression plus empirical Bayes). Results from simulation studies showed that pLARmEB was more powerful in QTN detection and more accurate in QTN effect estimation, had less false positive rate and required less computing time than Bayesian hierarchical generalized linear model, efficient mixed model association (EMMA) and least angle regression plus empirical Bayes. pLARmEB, multilocus random-SNP-effect mixed linear model and fast multilocus random-SNP-effect EMMA methods had almost equal power of QTN detection in simulation experiments. However, only pLARmEB identified 48 previously reported genes for 7 flowering time-related traits in Arabidopsis thaliana.
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ETR COMPLEX. CAMERA FACING SOUTH. FROM BOTTOM OF VIEW TO ...
ETR COMPLEX. CAMERA FACING SOUTH. FROM BOTTOM OF VIEW TO TOP: MTR, MTR SERVICE BUILDING, ETR CRITICAL FACILITY, ETR CONTROL BUILDING (ATTACHED TO ETR), ETR BUILDING (HIGH-BAY), COMPRESSOR BUILDING (ATTACHED AT LEFT OF ETR), HEAT EXCHANGER BUILDING (JUST BEYOND COMPRESSOR BUILDING), COOLING TOWER PUMP HOUSE, COOLING TOWER. OTHER BUILDINGS ARE CONTRACTORS' CONSTRUCTION BUILDINGS. INL NEGATIVE NO. 56-4105. Unknown Photographer, ca. 1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID
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CALFED--An experiment in science and decisionmaking
Taylor, Kimberly A.; Jacobs, Katharine L.; Luoma, Samuel N.
2003-01-01
The CALFED Bay-Delta Program faces a challenging assignment: to develop a collaborative state-federal management plan for the complex river system and involve multiple stakeholders (primarily municipal, agricultural, and environmental entities) whose interests frequently are in direct conflict. Although many resource-management issues involve multiple stakeholders and conflict is integral to their discussion, the CALFED experience is unique because of its shared state and federal roles, the magnitude and significance of stakeholder participation, and the complexity of the scientific issues involved.
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NASA Technical Reports Server (NTRS)
Thompson, David E.; Rajkumar, T.; Clancy, Daniel (Technical Monitor)
2002-01-01
The San Francisco Bay Delta is a large hydrodynamic complex that incorporates the Sacramento and San Joaquin Estuaries, the Burman Marsh, and the San Francisco Bay proper. Competition exists for the use of this extensive water system both from the fisheries industry, the agricultural industry, and from the marine and estuarine animal species within the Delta. As tidal fluctuations occur, more saline water pushes upstream allowing fish to migrate beyond the Burman Marsh for breeding and habitat occupation. However, the agriculture industry does not want extensive salinity intrusion to impact water quality for human and plant consumption. The balance is regulated by pumping stations located alone the estuaries and reservoirs whereby flushing of fresh water keeps the saline intrusion at bay. The pumping schedule is driven by data collected at various locations within the Bay Delta and by numerical models that predict the salinity intrusion as part of a larger model of the system. The Interagency Ecological Program (IEP) for the San Francisco Bay/Sacramento-San Joaquin Estuary collects, monitors, and archives the data, and the Department of Water Resources provides a numerical model simulation (DSM2) from which predictions are made that drive the pumping schedule. A problem with this procedure is that the numerical simulation takes roughly 16 hours to complete a C: prediction. We have created a neural net, optimized with a genetic algorithm, that takes as input the archived data from multiple stations and predicts stage, salinity, and flow at the Carquinez Straits (at the downstream end of the Burman Marsh). This model seems to be robust in its predictions and operates much faster than the current numerical DSM2 model. Because the system is strongly tidal driven, we used both Principal Component Analysis and Fast Fourier Transforms to discover dominant features within the IEP data. We then filtered out the dominant tidal forcing to discover non-primary tidal effects, and used this to enhance the neural network by mapping input-output relationships in a more efficient manner. Furthermore, the neural network implicitly incorporates both the hydrodynamic and water quality models into a single predictive system. Although our model has not yet been enhanced to demonstrate improve pumping schedules, it has the possibility to support better decision-making procedures that may then be implemented by State agencies if desired. Our intention is now to use this model in the smaller Elkhorn Slough complex near Monterey Bay where no such hydrodynamic model currently exists. At the Elkhorn Slough, we are fusing the neural net model of tidally-driven flow with in situ flow data and airborne and satellite remote sensation data. These further constrain the behavior of the model in predicting the longer-term health and future of this vital estuary.
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New Jersey Tide Telemetry System
Hoppe, Heidi L.
2007-01-01
Each summer the population of the barrier-island communities of New Jersey increases by tens of thousands. When a coastal storm threatens these communities, the limited number of bridges and causeways that connect the islands with the mainland become overcrowded, making evacuations from the barrier islands to the mainland difficult. Timely evacuation depends on well-defined emergency evacuation plans used in conjunction with accurate flood forecasting and up to the minute (real-time) tide-level information. The 'Great Nor'easter' storm that struck the coastal areas of New Jersey on December 11, 1992, caused about $270 million in insured damages to public and private property (Dorr and others, 1995). Most of the damage was due to tidal flooding and storm surge, which were especially severe along the back bay areas. Comprehensive and reliable tide-level and meteorological data for the back bays was needed to make accurate flood forecasts. Collection of tidal data for the ocean and large bays was adequately covered by the National Oceanic and Atmospheric Administration's National Ocean Service (NOAA's NOS), but in New Jersey little to no data are available for the back-bay areas. The back bays behave quite differently than the ocean as a result of the complex interaction between the winds and the geometry of the inlets and bays. A slow moving Nor'easter can keep tide levels in back bays several feet higher than the ocean tide by not allowing tides to recede, resulting in flooding of bridges and causeways that link the barrier islands to the mainland. The U.S. Geological Survey (USGS), in cooperation with the New Jersey Department of Transportation (NJDOT), designed and installed the New Jersey Tide Telemetry System (NJTTS) with assistance from NOAA's NOS in 1997. This system is part of a statewide network of tide gages, weather stations, and stream gages that collect data in real time. The NJTTS supplies comprehensive, reliable real-time tide-level and meteorological data for flood-prone areas along the New Jersey shore and back bays. These data are transmitted to computer base stations located at offices of the National Weather Service, New Jersey State Police (NJSP), NJDOT, county emergency management agencies, other critical decision-making centers, and the World Wide Web (WWW). This fact sheet describes the NJTTS and identifies its benefits.
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Orth, Robert J.; Williams, Michael R.; Marion, Scott R.; Wilcox, David J.; Carruthers, Tim J.B.; Moore, Kenneth A.; Kemp, W.M.; Dennison, William C.; Rybicki, Nancy B.; Peter Bergstrom,; Batiuk, Richard A.
2010-01-01
Chesapeake Bay supports a diverse assemblage of marine and freshwater species of submersed aquatic vegetation (SAV) whose broad distributions are generally constrained by salinity. An annual aerial SAV monitoring program and a bi-monthly to monthly water quality monitoring program have been conducted throughout Chesapeake Bay since 1984. We performed an analysis of SAV abundance and up to 22 environmental variables potentially influencing SAV growth and abundance (1984-2006). Historically, SAV abundance has changed dramatically in Chesapeake Bay, and since 1984, when SAV abundance was at historic low levels, SAV has exhibited complex changes including long-term (decadal) increases and decreases, as well as some large, single-year changes. Chesapeake Bay SAV was grouped into three broad-scale community-types based on salinity regime, each with their own distinct group of species, and detailed analyses were conducted on these three community-types as well as on seven distinct case-study areas spanning the three salinity regimes. Different trends in SAVabundance were evident in the different salinity regimes. SAV abundance has (a) continually increased in the low-salinity region; (b) increased initially in the medium-salinity region, followed by fluctuating abundances; and (c) increased initially in the high-salinity region, followed by a subsequent decline. In all areas, consistent negative correlations between measures of SAV abundance and nitrogen loads or concentrations suggest that meadows are responsive to changes in inputs of nitrogen. For smaller case-study areas, different trends in SAV abundance were also noted including correlations to water clarity in high-salinity case-study areas, but nitrogen was highly correlated in all areas. Current maximum SAV coverage for almost all areas remain below restoration targets, indicating that SAV abundance and associated ecosystem services are currently limited by continued poor water quality, and specifically high nutrient concentrations, within Chesapeake Bay. The nutrient reductions noted in some tributaries, which were highly correlated to increases in SAV abundance, suggest management activities have already contributed to SAV increases in some areas, but the strong negative correlation throughout the Chesapeake Bay between nitrogen and SAV abundance also suggests that further nutrient reductions will be necessary for SAV to attain or exceed restoration targets throughout the bay.
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Bay in Flux: Marine Climate Impacts, Art and Tablet App Design
NASA Astrophysics Data System (ADS)
Kintisch, E. S.
2012-12-01
Bay in Flux is a year-long experimental effort to design and develop interactive tablet computer apps exploring the marine impacts of climate change. The goal is to convey, visualize and enliven scientific ideas around this topic, while engaging a broad audience through the design of interactive content. Pioneering new models of scientist-artist collaborations are a central part of the effort as well. The project begins with an innovative studio class at the Rhode Island School of Design (RISD) called Bay in Flux, taught in the Fall 2012 semester. Its three instructor team includes two artist-designers and one science reporter, with active collaborations from affiliated marine scientists. The subject matter focus is the Narragansett Bay, which has shown physical, chemical and ecological impacts of climate change, along with the ongoing efforts of researchers to explain and characterize it. In exploring this rich story, we intend to innovate pioneering means of handling narrative material on interactive e-books, enable data collection by citizen scientists or devise game-like simulations to enable audiences to explore and understand complex natural systems. The lessons we seek to learn in this project include: how to effectively encourage collaborations between scientists and designers around digital design; how to pioneer new and compelling ways to tell science-based nonfiction stories on tablets; and how art and design students with no scientific training can engage with complex scientific content effectively. The project will also challenge us to think about the tablet computer not only as a data output device -- in which the user reads, watches, or interacts with provided content -- but also as a dynamic and ideal tool for mobile data input, enabling citizen science projects and novel connections between working researchers and the public. The intended audience could include high school students or older audiences who currently eschew science journalism. HTML5 is the likely language of choice, with the iPad being the initial intended platform. Following the fall class, a spring 2013 effort will involve developing a prototype app. Partners in the Bay in Flux project are the Knight Science Journalism program at MIT, RISD and the National Science Foundation's Rhode Island Experimental Program to Stimulate Competitive Research. Ultimately, the goal is to foster new ways for artists and designers to collaborate with scientists in the environmental field while reaching broad audiences.
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Mapping of wildlife habitat in Farmington Bay, Utah
NASA Technical Reports Server (NTRS)
Jaynes, R. A.; Willie, R. D. (Principal Investigator)
1982-01-01
Mapping was accomplished through the interpretation of high-altitude color infrared photography. The feasibility of utilizing LANDSAT digital data to augment the analysis was explored; complex patterns of wildlife habitat and confusion of spectral classes resulted in the decision to make limited use of LANDSAT data in the analysis. The final product is a map which delineates wildlife habitat at a scale of 1:24,000. The map is registered to and printed on a screened U.S.G.S. quadrangle base map. Screened delineations of shoreline contours, mapped from a previous study, are also shown on the map. Intensive field checking of the map was accomplished for the Farmington Bay Waterfowl Management Area in August 1981; other areas on the map received only spot field checking.
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Mineral compositions of plutonic rocks from the Lewis Hills massif, Bay of Islands ophiolite
NASA Technical Reports Server (NTRS)
Smith, Susan E.; Elthon, Don
1988-01-01
Mineral compositions of residual and cumulate rocks from the Lewis Hills massif of the Bay of Islands ophiolite complex are reported and interpreted in the context of magnetic processes involved in the geochemical evolution of spatially associated diabase dikes. The mineral compositions reflect greater degrees of partial melting than most abyssal peridotites do and appear to represent the most depleted end of abyssal peridotite compositions. Subsolidus equilibration between Cr-Al spinal and olivine generally has occurred at temperatures of 700 to 900 C. The spinel variations agree with the overall fractionation of basaltic magmas producing spinels with progressively lower Cr numbers. The compositions of clinopyroxenes suggest that the fractionation of two different magma series produced the various cumulate rocks.
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MMS Spacecraft Uncrated & Moved
2014-10-29
Two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, the lower stack, mini-stack number 1, begin the trip from the Building 2 south encapsulation bay to the Building 1 high bay at the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. The MMS upper stack, mini-stack number 2, is scheduled to arrive in about two weeks. MMS is a Solar Terrestrial Probes mission comprising four identically instrumented spacecraft that will use Earth’s magnetosphere as a laboratory to study the microphysics of three fundamental plasma processes: magnetic reconnection, energetic particle acceleration and turbulence. Launch aboard a United Launch Alliance Atlas V rocket from Space Launch Complex 41 on Cape Canaveral Air Force Station is targeted for March 12, 2015.
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MMS Spacecraft Uncrated & Moved
2014-10-29
Preparations are underway to tow two of the observatories, the lower stack, mini-stack number 1, for NASA's Magnetospheric Multiscale Observatory, or MMS, from the Building 2 south encapsulation bay to the Building 1 high bay at the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. The MMS upper stack, mini-stack number 2, is scheduled to arrive in about two weeks. MMS is a Solar Terrestrial Probes mission comprising four identically instrumented spacecraft that will use Earth’s magnetosphere as a laboratory to study the microphysics of three fundamental plasma processes: magnetic reconnection, energetic particle acceleration and turbulence. Launch aboard a United Launch Alliance Atlas V rocket from Space Launch Complex 41 on Cape Canaveral Air Force Station is targeted for March 12, 2015.
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MMS Spacecraft Uncrated & Moved
2014-10-29
Workers surround two of the observatories, the lower stack, mini-stack number 1, for NASA's Magnetospheric Multiscale Observatory, or MMS, on their trip from the Building 2 south encapsulation bay to the Building 1 high bay at the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. The MMS upper stack, mini-stack number 2, is scheduled to arrive in about two weeks. MMS is a Solar Terrestrial Probes mission comprising four identically instrumented spacecraft that will use Earth’s magnetosphere as a laboratory to study the microphysics of three fundamental plasma processes: magnetic reconnection, energetic particle acceleration and turbulence. Launch aboard a United Launch Alliance Atlas V rocket from Space Launch Complex 41 on Cape Canaveral Air Force Station is targeted for March 12, 2015.
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NASA Astrophysics Data System (ADS)
Gavrilova, G. S.; Sukhin, I. Yu.
2011-06-01
In Kievka Bay of the Sea of Japan, the population of the Japanese sea cucumber Apostichopus japonicus inhabits the areas of coarse sediments and complex bottom topography. These distributional patterns are closely related to the species' ecology, i.e., to the demand for protection against the wave turbulence. The aggregationing coverage of the sea cucumber population is about 80 hectares, where ˜200 thousand animals were accounted for in the last years. The aggregation's area varies during the year, which is closely related to the species' biological peculiarities, such as their behavioral patterns and the redistribution of their food resources. A significant increase of the juvenile population occurred after the farm-reared sea cucumber spat were released in 2003.
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Previous work had indicated that the Virginian Province Index did not perform well in a smaller estuarine complex. While it was hoped that the existing Chesapeake Bay Benthic Index of Biotic Integrity, with its greater number of metrics and habitat separation would be more adapt...
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USDA-ARS?s Scientific Manuscript database
The effects of two novel adjuvants, QCDC (Quil A/cholesterol/DDA/Carbopol) and QCDCRT (QCDC/Bay R1005/cytosine-phosphate-guanosine oligodeoxynucleotides, CpG) emulsified with profilin, a conserved Eimeria recombinant protein, against avian coccidiosis were determined in broiler chickens. Chickens we...
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USDA-ARS?s Scientific Manuscript database
This study investigated the ability of two novel adjuvant formulations, QCDC (Quil A/cholesterol/DDA/Carbopol) and QCDCR (QCDC/Bay R1005), in combination with a recombinant profilin vaccine, to modulate host protective immunity and to alter gene expression during experimental avian coccidiosis. Vac...
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Environmental assessment of complex mixtures typically requires integration of chemical and biological measurements. This study demonstrates the use of a combination of instrumental chemical analyses, effects-based monitoring, and bio-effects prediction approaches to help identi...
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2016-09-25
marine soundscape , is the quietest time of the day (Heenehan 2016; Navy 2016) and therefore they may not be vocalizing frequently. Based on...Heenehan, H. L. (2016). Soundscape Ecology of Hawaiian Spinner Dolphin Resting Bays (Doctoral dissertation, Duke University). Hotchkin, C. F., Shoemaker
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Integrated geostatistics for modeling fluid contacts and shales in Prudhoe Bay
DOE Office of Scientific and Technical Information (OSTI.GOV)
Perez, G.; Chopra, A.K.; Severson, C.D.
1997-12-01
Geostatistics techniques are being used increasingly to model reservoir heterogeneity at a wide range of scales. A variety of techniques is now available with differing underlying assumptions, complexity, and applications. This paper introduces a novel method of geostatistics to model dynamic gas-oil contacts and shales in the Prudhoe Bay reservoir. The method integrates reservoir description and surveillance data within the same geostatistical framework. Surveillance logs and shale data are transformed to indicator variables. These variables are used to evaluate vertical and horizontal spatial correlation and cross-correlation of gas and shale at different times and to develop variogram models. Conditional simulationmore » techniques are used to generate multiple three-dimensional (3D) descriptions of gas and shales that provide a measure of uncertainty. These techniques capture the complex 3D distribution of gas-oil contacts through time. The authors compare results of the geostatistical method with conventional techniques as well as with infill wells drilled after the study. Predicted gas-oil contacts and shale distributions are in close agreement with gas-oil contacts observed at infill wells.« less
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Views of the Sea Floor in Northern Monterey Bay, California
Storlazzi, Curt D.; Golden, Nadine E.; Finlayson, David P.
2008-01-01
A sonar survey that produced unprecedented high-resolution images of the sea floor in northern Monterey Bay was conducted in 2005 and 2006. The survey, performed over 14 days by the U.S. Geological Survey (USGS), consisted of 172 tracklines and over 300 million soundings and covered an area of 12.2 km2 (4.7 mi2). The goals of this survey were to collect high-resolution bathymetry (depth to the sea floor) and acoustic backscatter data (amount of sound energy bounced back from the sea floor, which provides information on sea-floor hardness and texture) from the inner continental shelf. These data will provide a baseline for future change analyses, geologic mapping, sediment- and contaminant-transport studies, benthic-habitat delineation, and numerical modeling efforts. The survey shows that the inner shelf in this area is extremely varied in nature, encompassing flat sandy areas, faults, boulder fields, and complex bedrock ridges that support rich marine ecosystems. Furthermore, many of these complex bedrock ridges form the ?reefs? that result in a number of California?s classic surf breaks.
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Cleary, D F R; Polónia, A R M; Renema, W; Hoeksema, B W; Rachello-Dolmen, P G; Moolenbeek, R G; Budiyanto, A; Yahmantoro; Tuti, Y; Giyanto; Draisma, S G A; Prud'homme van Reine, W F; Hariyanto, R; Gittenberger, A; Rikoh, M S; de Voogd, N J
2016-09-30
Substrate cover, water quality parameters and assemblages of corals, fishes, sponges, echinoderms, ascidians, molluscs, benthic foraminifera and macroalgae were sampled across a pronounced environmental gradient in the Jakarta Bay-Thousand Islands reef complex. Inshore sites mainly consisted of sand, rubble and turf algae with elevated temperature, dissolved oxygen, pH and chlorophyll concentrations and depauperate assemblages of all taxa. Live coral cover was very low inshore and mainly consisted of sparse massive coral heads and a few encrusting species. Faunal assemblages were more speciose and compositionally distinct mid- and offshore compared to inshore. There were, however, small-scale differences among taxa. Certain midshore sites, for example, housed assemblages resembling those typical of the inshore environment but this differed depending on the taxon. Substrate, water quality and spatial variables together explained from 31% (molluscs) to 72% (foraminifera) of the variation in composition. In general, satellite-derived parameters outperformed locally measured parameters. Copyright © 2016 Elsevier Ltd. All rights reserved.
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BFDCA: A Comprehensive Tool of Using Bayes Factor for Differential Co-Expression Analysis.
Wang, Duolin; Wang, Juexin; Jiang, Yuexu; Liang, Yanchun; Xu, Dong
2017-02-03
Comparing the gene-expression profiles between biological conditions is useful for understanding gene regulation underlying complex phenotypes. Along this line, analysis of differential co-expression (DC) has gained attention in the recent years, where genes under one condition have different co-expression patterns compared with another. We developed an R package Bayes Factor approach for Differential Co-expression Analysis (BFDCA) for DC analysis. BFDCA is unique in integrating various aspects of DC patterns (including Shift, Cross, and Re-wiring) into one uniform Bayes factor. We tested BFDCA using simulation data and experimental data. Simulation results indicate that BFDCA outperforms existing methods in accuracy and robustness of detecting DC pairs and DC modules. Results of using experimental data suggest that BFDCA can cluster disease-related genes into functional DC subunits and estimate the regulatory impact of disease-related genes well. BFDCA also achieves high accuracy in predicting case-control phenotypes by using significant DC gene pairs as markers. BFDCA is publicly available at http://dx.doi.org/10.17632/jdz4vtvnm3.1. Copyright © 2016 Elsevier Ltd. All rights reserved.
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NASA Astrophysics Data System (ADS)
Oms, Pierre-Emmanuel; Bailly du Bois, Pascal; Dumas, Franck; Lazure, Pascal; Morillon, Mehdi; Solier, Luc; Voiseux, Claire; Le Corre, Cédric; Maire, Donovan
2017-04-01
New measurements of a radioactive tracer (tritium) on the whole continental shelf of the Bay of Biscay during several oceanographic campaigns between 2008 and 2016 allow comparison with results of the plume dispersion from the regional circulation model, MARS3D (Lazure and Dumas, 2008). Seaward dispersion of freshwater in the Bay of Biscay is highly variable in time and depends on many processes like tide, wind, freshwater runoff or water mass stratification. Until now salinity was a useful tracer to describe dispersion of freshwater, but the complexity to account for these different sources require an additional conservative tracer. Tritium (3H) is a radionuclide tracer released as HTO in the Bay of Biscay by nuclear power plant through two French rivers, Loire and Gironde. Tritium inflow from Loire and Gironde are well known thanks to plants operator data and an effort of daily measurements. Indeed an automated and daily integrated sampling system is deployed in the Loire River and the Gironde Estuary. These plumes are clearly detectable over the continental shelf despite very low tritium concentrations (0.05 - 0.5 Bq/L, 0.5 - 5 TU). In order to determine such low tritium concentrations in the Bay of Biscay, we use a mass spectrometer to measure the 3He (gas) produced by radioactive disintegration of tritium after 3He ingrowth (1 - 6 months). The aim of this work is to describes and quantify the dispersion processes occurring in the continental shelf according to seasons. Thanks to assessments of the model dispersion compared to in-situ measurements, quantification of the residential time of freshwater in the continental shelf as well as quantification of their transfer from continental shelf to abyssal plain is possible. The 3H/S ratio will allow an estimation of respective inputs from Loire and Gironde in the bay.
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Wind-induced circulation in a large tropical lagoon: Chetumal Bay
NASA Astrophysics Data System (ADS)
Palacios, E.; Carrillo, L.
2013-05-01
Chetumal Bay is a large tropical lagoon located at the Mesoamerican Reef System. Windinduced circulation in this basin was investigated by using direct measurements of current, sea level, and 2d barotropic numerical model. Acoustic Doppler Profiler (ADP) transects covering the north of Chetumal Bay during two campaigns September 2006 and March 2007 were used. The 2d barotropic numerical model was ROMs based and wind forced. Wind information was obtained from a meteorological station located at ECOSUR Chetumal. Sea level data was collected from a pressure sensor deployed in the lagoon. A seasonal pattern of circulation was observed. From observations, during September 2006, a northward flow was shown in most part of the bay and a southward flow in the eastern coast was observed with velocities ranged from 6 cm s-1 to 36 cm s-1. In March 2007, the current pattern was more complex; divergences and converges were identified. The dominant circulation was northward in eastern portion, and southward in the central and western zone. The average current speed was 6 cm s-1 with maximum values of 26 -34 cm s-1. During September 2006 predominant wind was easternsoutheastern and during March 2007, northerly wind events were recorded. Sea level amplitude responded quickly to changes in the magnitude and direction of the wind. Results of sea level and circulation from the 2d barotropic numerical model agreed with observations at first approximation.
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Dai, Tianjiao; Zhang, Yan; Tang, Yushi; Bai, Yaohui; Tao, Yile; Huang, Bei; Wen, Donghui
2016-10-01
Coastal areas are land-sea transitional zones with complex natural and anthropogenic disturbances. Microorganisms in coastal sediments adapt to such disturbances both individually and as a community. The microbial community structure changes spatially and temporally under environmental stress. In this study, we investigated the microbial community structure in the sediments of Hangzhou Bay, a seriously polluted bay in China. In order to identify the roles and contribution of all microbial taxa, we set thresholds as 0.1% for rare taxa and 1% for abundant taxa, and classified all operational taxonomic units into six exclusive categories based on their abundance. The results showed that the key taxa in differentiating the communities are abundant taxa (AT), conditionally abundant taxa (CAT), and conditionally rare or abundant taxa (CRAT). A large population in conditionally rare taxa (CRT) made this category collectively significant in differentiating the communities. Both bacteria and archaea demonstrated a distance decay pattern of community similarity in the bay, and this pattern was strengthened by rare taxa, CRT and CRAT, but weakened by AT and CAT. This implied that the low abundance taxa were more deterministically distributed, while the high abundance taxa were more ubiquitously distributed. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Kuhl, D.E.; Sargent, F.J.; Leary, T.J.
1997-06-01
Seagrasses form the foundation of complex, fragile communities that include marine and estuarine animals, especially larval and juvenile fish, providing critical shelter and sustenance. Seagrasses also have a role in providing habitat for waterfowl, marine turtles and manimals. In addition, seagrasses improve water quality by stabilizing mobile sediments and converting some pollutants into plant biomass. The issue of propeller scarring or propeller dredging in seagrass beds has received much attention since 1990. The scarring of seagrass results from personal watercraft. Heightened interest has instigated numerous monitoring and mapping projects on propeller scarring and regrowth characteristics within seagrasses. The study areasmore » selected for this paper are located within Tampa Bay, Florida. Specifically, they are Shell Island and Miquel Bay. Spatial monitoring for the extent of seagrass scarring in the Tampa Bay region was conducted in two ways, a regional (general) approach and a site specific (detailed) approach. Regional monitoring assessed the status of seagrass in Tampa Bay and identified {open_quote}hot spots{close_quote}. After identifying {open_quote}hot spots{close_quote}, boat surveys were used to confirm or deny the initial assessment. This poster involves the design of a propeller scarring monitoring program using several methods: Hi8 video, digital cameras, film cameras, and differential GPS combined with Arcview. A pilot program to evaluate the adequacy of these monitoring devices and the recommendation of specific actions in areas of severe propeller scarring will be presented.« less
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Marlow, M. S.; Hart, P.E.; Carlson, P.R.; Childs, J. R.; Mann, D. M.; Anima, R.J.; Kayen, R.E.
1996-01-01
We collected high-resolution seismic reflection profiles in the southern part of San Francisco Bay in 1992 and 1993 to investigate possible Holocene faulting along postulated transbay bedrock fault zones. The initial analog records show apparent offsets of reflection packages along sharp vertical boundaries. These records were originally interpreted as showing a complex series of faults along closely spaced, sharp vertical boundaries in the upper 10 m (0.013 s two-way travel time) of Holocene bay mud. A subsequent survey in 1994 was run with a different seismic reflection system, which utilized a higher power source. This second system generated records with deeper penetration (max. 20 m, 0.026 s two-way travel time) and demonstrated that the reflections originally interpreted as fault offsets by faulting were actually laterally continuous reflection horizons. The pitfall in the original interpretations was caused by lateral variations in the amplitude brightness of reflection events, coupled with a long (greater than 15 ms) source signature of the low-power system. These effects combined to show apparent offsets of reflection packages along sharp vertical boundaries. These boundaries, as shown by the second system, in fact occur where the reflection amplitude diminishes abruptly on laterally continuous reflection events. This striking lateral variation in reflection amplitude is attributable to the localized presence of biogenic(?) gas.
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NASA Astrophysics Data System (ADS)
Hatzianestis, Ioannis
2015-04-01
Hydrocarbons are abundant components of the organic material in coastal zones. Their sources are mainly anthropogenic, but several natural ones have also been recognized. Among hydrocarbons, the polycyclic aromatic ones (PAHs) have received special attention since they considered as hazardous environmental chemicals and are included in priority pollutant lists. The purpose of this study was to investigate the distribution, sources and transport pathways of hydrocarbons in marine areas in Greece directly influenced from the operation of major industrial units in the coastal zone by using a molecular marker approach, characteristic compositional patterns and related indices and also to evaluate their potential toxicity. Thirty two surface sediment samples were collected from three marine areas: a) Antikyra bay in Korinthiakos gulf, affected from the operation of an alumina and production plant b) Larymna bay in Noth Evoikos, affected from the operation of a nickel production plant and c) Aliveri bay in South Evoikos Gulf, affected from a cement production plant. In all the studied areas aquaculture and fishing activities have been also developed in the coastal zone. High aliphatic hydrocarbon (AHC) concentrations (~500 μg/g), indicating significant petroleum related inputs, were measured only in Antikyra bay. In all the other samples, AHC values were below 100 μg/g. N-alkanes were the most prominent resolved components (R) with an elevated odd to even carbon number preference, revealing the high importance of terrestrial inputs in the study areas. The unresolved complex mixture (UCM) was the major component of the aliphatic fraction (UCM/R > 4), indicating a chronic oil pollution. A series of hopanes were also identified, with patterns characteristic of oil-derived hydrocarbons, further confirming the presence of pollutant inputs from fossil fuel products. Extremely high PAH concentrations (> 100,000 ng/g) were found in the close vicinity of the alumina production plant in Antikyra bay. High levels of PAHs up to 22,000 ng/g were also found in Aliveri bay, whereas lower values up to 7500 ng/g, but still indicating significant pollution, were measured close to the nickel production plant in Larymna bay. The examination of PAH molecular indices revealed that in Antikyra and Larymna bays more than 80% of the PAHs have pyrolytic origin coming from various combustion sources. On the contrary, in Aliveri bay about 60% of the PAHs are related to petrogenic/petroleum inputs. With respect to ecotoxicological effects, mean quotient Effect-Range Median (m-ERM) values, higher than 1.5, were calculated in Antikyra bay, indicating a high probability (76%) of toxicity. In Aliveri and Larymna bays the m-ERM values were between 0.11 and 0.5 bay suggesting a lower probability (21%) of toxicity. Overall, the results of our study reveal that high quantities of PAHs produced from land point sources such as the industrial units can enter into small coastal marine areas supporting activities such as aquaculture and fishing. Thus, desirable and permitted uses must be well defined and regulatory frameworks must be established.
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Mejia, F.; Saiki, M.K.; Takekawa, John Y.
2008-01-01
This study was conducted to characterize fishery resources inhabiting salt-evaporation ponds and sloughs in South San Francisco Bay, and to identify key environmental variables that influence distribution of fishes. The ponds, which were originally constructed and operated for commercial production of salt, have undergone preliminary modifications (installation of culverts, gates, and other water-control structures) in preparation for full restoration to mostly tidal wetlands over the next 2 decades. We sampled fish from two salt-pond complexes (Alviso complex and Eden Landing complex), each consisting of several pond systems and their associated sloughs. Cluster analysis of species of fish indicated that at least two species assemblages were present, one characteristic of ponds and the other characteristic of sloughs and slough-like ponds. The slough-like ponds exhibited water-quality conditions (especially salinity) that resembled conditions found in the sloughs. Pond fishes were represented by 12 species, whereas slough fishes were represented by 22 species. Except for bay pipefish (Syngnathus leptorhynchus), which was unique to ponds, all species present in ponds also were in sloughs and slough-like ponds. These results indicated that species of fish in ponds originated from the sloughs. According to canonical-discriminant analysis, four environmental variables were useful for discriminating between the two species assemblages. Most discriminatory power was contributed by the index of habitat connectivity, a measure of minimum distance that a fish must travel to reach a particular pond from the nearest slough. Apparently, as fish from sloughs enter and move through interconnected salt ponds, environmental stress factors increase in severity until only the more tolerant species remain. The most likely source of stress is salinity, because this variable was second in importance to the index of habitat connectivity in discriminating between the two species assemblages. Water temperature and concentration of dissolved oxygen also seemingly influenced spatial distribution of fishes, although they were less important than salinity.
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Simulation of ground-water discharge to Biscayne Bay, southeastern Florida
Langevin, Christian David
2001-01-01
As part of the Place-Based Studies Program, the U.S. Geological Survey initiated a project in 1996, in cooperation with the U.S. Army Corps of Engineers, to quantify the rates and patterns of submarine ground-water discharge to Biscayne Bay. Project objectives were achieved through field investigations at three sites (Coconut Grove, Deering Estate, and Mowry Canal) along the coastline of Biscayne Bay and through the development and calibration of variable-density, ground-water flow models. Two-dimensional, vertical cross-sectional models were developed for steady-state conditions for the Coconut Grove and Deering Estate transects to quantify local-scale ground-water discharge patterns to Biscayne Bay. A larger regional-scale model was developed in three dimensions to simulate submarine ground-water discharge to the entire bay. The SEAWAT code, which is a combined version of MODFLOW and MT3D, was used to simulate the complex variable-density flow patterns. Field data suggest that ground-water discharge to Biscayne Bay relative to the shoreline is restricted to within 300 meters at Coconut Grove, 600 to 1,000 meters at Deering Estate, and 100 meters at Mowry Canal. The vertical cross-sectional models, which were calibrated to the field data using the assumption of steady state, tend to focus ground-water discharge to within 50 to 200 meters of the shoreline. With homogeneous distributions for aquifer parameters and a constant-concentration boundary for Biscayne Bay, the numerical models could not reproduce the lower ground-water salinities observed beneath the bay, which suggests that further research may be necessary to improve the accuracy of the numerical simulations. Results from the cross-sectional models, which were able to simulate the approximate position of the saltwater interface, suggest that longitudinal dispersivity ranges between 1 and 10 meters, and transverse dispersivity ranges from 0.1 to 1 meter for the Biscayne aquifer. The three-dimensional, regional-scale model was calibrated to ground-water heads, canal baseflow, and the general position of the saltwater interface for nearly a 10-year period from 1989 to 1998. The mean absolute error between observed and simulated head values is 0.15 meter. The mean absolute error between observed and simulated baseflow is 3 x 105 cubic meters per day. The position of the simulated saltwater interface generally matches the position observed in the field, except for areas north of the Miami Canal where the simulated saltwater interface is located about 5 kilometers inland of the observed saltwater interface. Results from the regional-scale model suggest that the average rate of fresh ground-water discharge to Biscayne Bay for the 10-year period (1989-98) is about 2 x 105 cubic meters per day for 100 kilometers of coastline. This simulated discharge rate is about 6 percent of the measured surface-water discharge to Biscayne Bay for the same period. The model also suggests that nearly 100 percent of the fresh ground-water discharge is to the northern half of Biscayne Bay, north of the Cutler Drain Canal. South of the Cutler Drain Canal, coastal lowlands prevent the water table from rising high enough to drive measurable quantities of ground water to Biscayne Bay. Annual variations in sea-level elevation, which can be as large as 0.3 meter, have a substantial effect on rates of ground-water discharge. During 1989-98, simulated rates of ground-water discharge to Biscayne Bay generally are highest when sea level is relatively low.
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2018-05-02
The 2017 class of astronaut candidates are at United Launch Alliance's Space Launch Complex 41 at Cape Canaveral Air Force Station (CCAFS) in Florida for a familiarization tour. They also toured facilities at Kennedy Space Center, including the Neil Armstrong Operations and Checkout Building high bay; the Launch Control Center, Launch Complex 39B, the Vehicle Assembly Building, Boeing's Commercial Crew and Cargo Facility, and SpaceX's Launch Complex 39A. The candidates will spend about two years getting to know the space station systems and learning how to spacewalk, speak Russian, control the International Space Station's robotic arm and fly T-38s, before they're eligible to be assigned to a mission.
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Holbrook, W.S.; Brocher, T.M.; ten Brink, Uri S.; Hole, J.A.
1996-01-01
Wide-angle seismic data collected during the Bay Area Seismic Imaging Experiment provide new glimpses of the deep structure of the San Francisco Bay Area Block and across the offshore continental margin. San Francisco Bay is underlain by a veneer (<300 m) of sediments, beneath which P wave velocities increase rapidly from 5.2 km/s to 6.0 km/s at 7 km depth, consistent with rocks of the Franciscan subduction assemblage. The base of the Franciscan at-15-18 km depth is marked by a strong wide-angle reflector, beneath which lies an 8- to 10-km-thick lower crust with an average velocity of 6.75??0.15 km/s. The lower crust of the Bay Area Block may be oceanic in origin, but its structure and reflectivity indicate that it has been modified by shearing and/or magmatic intrusion. Wide-angle reflections define two layers within the lower crust, with velocities of 6.4-6.6 km/s and 6.9-7.3 km/s. Prominent subhorizontal reflectivity observed at near-vertical incidence resides principally in the lowermost layer, the top of which corresponds to the "6-s reflector" of Brocher et al. [1994]. Rheological modeling suggests that the lower crust beneath the 6-s reflector is the weakest part of the lithosphere; the horizontal shear zone suggested by Furlong et al. [1989] to link the San Andreas and Hayward/Calaveras fault systems may actually be a broad zone of shear deformation occupying the lowermost crust. A transect across the continental margin from the paleotrench to the Hayward fault shows a deep crustal structure that is more complex than previously realized. Strong lateral variability in seismic velocity and wide-angle reflectivity suggests that crustal composition changes across major transcurrent fault systems. Pacific oceanic crust extends 40-50 km landward of the paleotrench but, contrary to prior models, probably does not continue beneath the Salinian Block, a Cretaceous arc complex that lies west of the San Andreas fault in the Bay Area. The thickness (10 km) and high lower-crustal velocity of Pacific oceanic crust suggest that it was underplated by magmatism associated with the nearby Pioneer seamount. The Salinian Block consists of a 15-km-thick layer of velocity 6.0-6.2 km/s overlying a 5-km-thick, high-velocity (7.0 km/s) lower crust that may be oceanic crust, Cretaceous arc-derived lower crust, or a magmatically underplated layer. The strong structural variability across the margin attests to the activity of strike-slip faulting prior to and during development of the transcurrent Pacific/North American plate boundary around 29 Ma. Copyright 1996 by the American Geophysical Union.
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A self-modifying cellular automaton model of historical urbanization in the San Francisco Bay area
Clarke, K.C.; Hoppen, S.; Gaydos, L.
1997-01-01
In this paper we describe a cellular automaton (CA) simulation model developed to predict urban growth as part of a project for estimating the regional and broader impact of urbanization on the San Francisco Bay area's climate. The rules of the model are more complex than those of a typical CA and involve the use of multiple data sources, including topography, road networks, and existing settlement distributions, and their modification over time. In addition, the control parameters of the model are allowed to self-modify: that is, the CA adapts itself to the circumstances it generates, in particular, during periods of rapid growth or stagnation. In addition, the model was written to allow the accumulation of probabilistic estimates based on Monte Carlo methods. Calibration of the model has been accomplished by the use of historical maps to compare model predictions of urbanization, based solely upon the distribution in year 1900, with observed data for years 1940, 1954, 1962, 1974, and 1990. The complexity of this model has made calibration a particularly demanding step. Lessons learned about the methods, measures, and strategies developed to calibrate the model may be of use in other environmental modeling contexts. With the calibration complete, the model is being used to generate a set of future scenarios for the San Francisco Bay area along with their probabilities based on the Monte Carlo version of the model. Animated dynamic mapping of the simulations will be used to allow visualization of the impact of future urban growth.
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NASA Astrophysics Data System (ADS)
Draisma, Stefano G. A.; Prud'homme van Reine, Willem F.; Herandarudewi, Sekar M. C.; Hoeksema, Bert W.
2018-01-01
The Jakarta Bay - Thousand Islands reef complex extends to more than 80 km in northwest direction from the major conurbation Jakarta (Indonesia) along a pronounced inshore to offshore environmental gradient. The present study aims to determine to what extent environmental factors can explain the composition of macroalgal communities on the reefs off Jakarta. Therefore, the presence-absence of 67 macroalgal taxa was recorded for 27 sampling sites along the inshore-offshore disturbance gradient and analysed with substrate variables and water quality variables. The macroalgal richness pattern matches the pattern of other reef taxa. The 27 sites could be assigned to one of four geographical zones with 85% certainty based on their macroalgal taxon assemblages. These four zones (i.e., Jakarta Bay and, respectively, South, Central, and North Thousand Islands) had significantly different macroalgal assemblages, except for the North and South zones. Along the nearshore gradient there was a greater shift in taxon composition than within the central Thousand Islands. The patterns of ten habitat and water quality variables resembled the macroalgal diversity patterns by 56%. All ten variables together explained 69% of the variation in macroalgal composition. Shelf depth, % sand cover, gelbstoff/detrital material, chlorophyll a concentration, seawater surface temperature, and % dead coral cover were the best predictors of seaweed flora composition. Furthermore, 44 macroalgal species represented new records for the area. The present study provides important baseline data of macroalgae in the area for comparison in future biodiversity assessments in the area and elsewhere in the region.
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Earth observations Cape Town, South Africa taken during the STS-97 mission
2000-12-10
STS097-711-069 (30 Nov. - 11 Dec. 2000) This view featuring Cape Town and the Western Cape Province in the Republic of South Africa was provided by one of the STS-97 astronauts using a 70mm handheld camera aboard the Earth-orbiting Space Shuttle Endeavour. The capital and largest city of Western Cape Province, Cape Town (1995 population in the urban and suburban area shows in excess of 1.9 million), is visible between False Bay (large, U-shaped bay) and a smaller bay along the Atlantic coast of the peninsula. Within the urban built-up area some of the infrastructure of Cape Town, including the city center and the harbor and waterfront facilities, can be identified near the small bay (middle left edge of the image). Table Mountain elevation of 3563 feet (1086 meters above sea level) separates the city center (north of the mountain) from the southern suburbs of Cape Town. The Cape of Good Hope, long famous as the gateway from the Atlantic Ocean to the Indian Ocean, is located at the southern tip of the claw-shaped peninsula. False Bay is a popular recreational region for the local residents of the greater Cape Town region, as well as a tourist attraction for people who live beyond the borders of South Africa. The lighter-colored terrain, mainly north of Cape Town, shows a landscape of large, cultivated field patterns. These coastal plains are separated from the interior by a chain of folded mountain ranges that include the Cedarberg (dark, linear, north/south aligned feature in the upper right corner) and the more complex, folded Herrivierberge Mountains (dark structure, right middle) that are located northeast of Cape Town.
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NASA Astrophysics Data System (ADS)
Oakey, Gordon N.; Chalmers, James A.
2012-10-01
A simplified plate kinematic model for the Paleogene motion of Greenland relative to North America has been developed to provide a new framework for modeling the oceanic spreading system in Baffin Bay and the intraplate tectonic development of the Davis Strait and Nares Strait regions of the Arctic. A single Euler rotation pole was calculated for the C13N to C24N Eocene motion of the Greenland Plate relative to North America using spreading centers and fracture zones interpreted from satellite derived gravity data in Baffin Bay combined with fracture zones in Labrador Sea from published sources. A single stage pole is proposed for the C25N to C27N portion of the Paleocene and a short-lived stage pole was found necessary to accommodate the C24N to C25N interval. This kinematic model has been used to reinterpret published shipborne magnetic profiles in central Baffin Bay to reveal a Paleocene spreading center and limits of both Eocene and Paleocene oceanic crust. Aeromagnetic data over northeastern Baffin Bay have been used to identify a new fracture zone in northern Baffin Bay. Plate reconstructions are presented incorporating constraints on plate boundaries from onshore and offshore geological and geophysical mapping. Within the Davis Strait, Paleocene oceanic crust was emplaced in an elongated rift that was subsequently inverted by approximately 300 km of Eocene transpression along the Ungava Fault Zone. In the Nares Strait Region, a "microplate" scenario is presented to explain the simultaneous formation of the Lancaster Sound Rift Basin and complex deformation within the Eurekan Orogenic Belt.
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NASA Astrophysics Data System (ADS)
Qi, Wei; Liu, Junguo; Yang, Hong; Sweetapple, Chris
2018-03-01
Global precipitation products are very important datasets in flow simulations, especially in poorly gauged regions. Uncertainties resulting from precipitation products, hydrological models and their combinations vary with time and data magnitude, and undermine their application to flow simulations. However, previous studies have not quantified these uncertainties individually and explicitly. This study developed an ensemble-based dynamic Bayesian averaging approach (e-Bay) for deterministic discharge simulations using multiple global precipitation products and hydrological models. In this approach, the joint probability of precipitation products and hydrological models being correct is quantified based on uncertainties in maximum and mean estimation, posterior probability is quantified as functions of the magnitude and timing of discharges, and the law of total probability is implemented to calculate expected discharges. Six global fine-resolution precipitation products and two hydrological models of different complexities are included in an illustrative application. e-Bay can effectively quantify uncertainties and therefore generate better deterministic discharges than traditional approaches (weighted average methods with equal and varying weights and maximum likelihood approach). The mean Nash-Sutcliffe Efficiency values of e-Bay are up to 0.97 and 0.85 in training and validation periods respectively, which are at least 0.06 and 0.13 higher than traditional approaches. In addition, with increased training data, assessment criteria values of e-Bay show smaller fluctuations than traditional approaches and its performance becomes outstanding. The proposed e-Bay approach bridges the gap between global precipitation products and their pragmatic applications to discharge simulations, and is beneficial to water resources management in ungauged or poorly gauged regions across the world.
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Using a Content Management System for Integrated Water Quantity, Quality and Instream Flows Modeling
NASA Astrophysics Data System (ADS)
Burgholzer, R.; Brogan, C. O.; Scott, D.; Keys, T.
2017-12-01
With increased population and water demand, in-stream flows can become depleted by consumptive uses and dilution of permitted discharges may be compromised. Reduced flows downstream of water withdrawals may increase the violation rate of bacterial concentrations from direct deposition by livestock and wildlife. Water storage reservoirs are constructed and operated to insure more stable supplies for consumptive demands and dilution flows, however their use comes at the cost of increased evaporative losses, potential for thermal pollution, interrupted fish migration, and reduced flooding events that are critical to maintain habitat and water quality. Due to this complex interrelationship between water quantity, quality and instream habitat comprehensive multi-disciplinary models must be developed to insure long-term sustainability of water resources and to avoid conflicts between drinking water, food and energy production, and aquatic biota. The Commonwealth of Virginia funded the expansion of the Chesapeake Bay Program Phase 5 model to cover the entire state, and has been using this model to evaluate water supply permit and planning since 2009. This integrated modeling system combines a content management system (Drupal and PHP) for model input data and leverages the modularity of HSPF with the custom segmentation and parameterization routines programmed by modelers working with the Chesapeake Bay Program. The model has been applied to over 30 Virginia Water Permits, instream flows and aquatic habitat models and a Virginias 30 year water supply demand projections. Future versions will leverage the Bay Model auto-calibration routines for adding small-scale water supply and TMDL models, utilize climate change scenarios, and integrate Virginia's reservoir management modules into the Chesapeake Bay watershed model, feeding projected demand and operational changes back up to EPA models to improve the realism of future Bay-wide simulations.
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Linkages between Alaskan sockeye salmon abundance, growth at sea, and climate, 1955-2002
Ruggerone, G.T.; Nielsen, J.L.; Bumgarner, J.
2007-01-01
We tested the hypothesis that increased growth of salmon during early marine life contributed to greater survival and abundance of salmon following the 1976/1977 climate regime shift and that this, in turn, led to density-dependent reductions in growth during late marine stages. Annual measurements of Bristol Bay (Bering Sea) and Chignik (Gulf of Alaska) sockeye salmon scale growth from 1955 to 2002 were used as indices of body growth. During the first and second years at sea, growth of both stocks tended to be higher after the 1976-1977 climate shift, whereas growth during the third year and homeward migration was often below average. Multiple regression models indicated that return per spawner of Bristol Bay sockeye salmon and adult abundance of western and central Alaska sockeye salmon were positively correlated with growth during the first 2 years at sea and negatively correlated with growth during later life stages. After accounting for competition between Bristol Bay sockeye and Asian pink salmon, age-specific adult length of Bristol Bay salmon increased after the 1976-1977 regime shift, then decreased after the 1989 climate shift. Late marine growth and age-specific adult length of Bristol Bay salmon was exceptionally low after 1989, possibly reducing their reproductive potential. These findings support the hypothesis that greater marine growth during the first 2 years at sea contributed to greater salmon survival and abundance, which in turn led to density-dependent growth during later life stages when size-related mortality was likely lower. Our findings provide new evidence supporting the importance of bottom-up control in marine ecosystems and highlight the complex dynamics of species interactions that continually change as salmon grow and mature in the ocean. ?? 2007 Elsevier Ltd. All rights reserved.
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Richardson, Leslie; Huber, Chris; Koontz, Lynne
2012-01-01
The National Wildlife Refuge System Improvement Act of 1997 requires all units of the National Wildlife Refuge System to be managed under a Comprehensive Conservation Plan. The Comprehensive Conservation Plan must describe the desired future conditions of a Refuge and provide long-range guidance and management direction to achieve refuge purposes. The Don Edwards San Francisco Bay National Wildlife Refuge, located at the south end of California's San Francisco Bay and one of seven refuges in the San Francisco Bay National Wildlife Refuge Complex, is in the process of developing a range of management goals, objectives, and strategies for the Comprehensive Conservation Plan. The Comprehensive Conservation Plan must contain an analysis of expected effects associated with current and proposed Refuge management strategies. For Refuge Comprehensive Conservation Plan planning, a regional economic analysis provides a means of estimating how current management (No Action Alternative) and proposed management activities (alternatives) affect the local economy. This type of analysis provides two critical pieces of information: (1) it illustrates the Don Edwards San Francisco Bay National Wildlife Refuge's contribution to the local community, and (2) it can help in determining whether economic effects are or are not a real concern in choosing among management alternatives. This report first presents a description of the local community and economy near the Don Edwards San Francisco Bay National Wildlife Refuge. Next, the methods used to conduct a regional economic impact analysis are described. An analysis of the final Comprehensive Conservation Plan management strategies that could affect stakeholders, residents, and the local economy is then presented. The management activities of economic concern in this analysis are: * Spending in the local community by Refuge visitors; * Refuge personnel salary spending; and * Refuge purchases of goods and services within the local community.
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NASA Astrophysics Data System (ADS)
Wang, Longhua; Ou, Linjian; Huang, Kaixuan; Chai, Chao; Wang, Zhaohui; Wang, Xiaomin; Jiang, Tao
2017-09-01
The spatial and temporal variability of the phytoplankton community structure in Daya Bay, South China Sea, were identified by using HPLC-CHEMTAX analytical techniques. The highest chlorophyll a (Chl a) concentrations were observed during summer (with an average value of 0.84 μg/L) and lowest ones during winter (with an average value of 0.33 μg/L). CHEMTAX processing revealed the seasonal succession of phytoplankton species in Daya Bay. During winter, diatoms were the dominant phytoplankton species and contributed 41.5% to total Chl a. Based on Chl a concentration, the average ratio of dinoflagellates to total phytoplankton biomass substantially increased with increasing temperature and nitrogen to phosphorus (N/P) ratio, reaching 52.2% in spring. Nutrient limitation shifted from phosphorus to nitrogen during summer. Moreover, this period was associated with the predominance of diatoms, which accounted for 71.1% of Chl a. Prasinophytes and cryptophytes were the other two dominant groups and particularly dominated during winter. Cyanobacteria became an important group during summer and autumn. Canonical correspondence analysis suggested that chrysophytes, dinoflagellates, and cryptophytes were strongly associated with high nitrate concentration, ammonium, dissolved inorganic nitrogen (DIN), and N/P ratio, and were negatively associated with temperature and phosphate. Diatoms and cyanobacteria were strongly associated with temperature, phosphate, and salinity, and are negatively influenced by nitrate, ammonium, DIN, and N/P ratio. Microscopic observations and pigment HPLC information were in good agreement for diatoms and dinoflagellates in the bay. This study demonstrated the usefulness of pigment analysis in investigating the distribution of phytoplankton groups in a complex physical environment, such as Daya Bay.
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Strain-induced shear instability in Liverpool Bay
NASA Astrophysics Data System (ADS)
Wihsgott, Juliane; Palmer, Matthew R.
2013-04-01
Liverpool Bay is a shallow subsection of the eastern Irish Sea with large tides (10 m), which drive strong tidal currents (1 ms-1). The Bay is heavily influenced by large freshwater inputs from several Welsh and English rivers that maintain a strong and persistent horizontal density gradient. This gradient interacts with the sheared tidal currents to strain freshwater over denser pelagic water on a semi-diurnal frequency. This Strain-Induced-Periodic-Stratification (SIPS) has important implications on vertical and horizontal mixing. The subtle interaction between stratification and turbulence in this complex environment is shown to be of critical importance to freshwater transport, and subsequently the fate of associated biogeochemical and pollutant pathways. Recent work identified an asymmetry of current ellipses due to SIPS that increases shear instability in the halocline with the potential to enhance diapycnal mixing. Here, we use data from a short, high intensity process study which reveals this mid-water mechanism maintains prolonged periods of sub-critical gradient Richardson number (Ri ≤ ¼) that suggests shear instability is likely. A time series of measurements from a microstructure profiler identifies the associated increase in turbulence is short lived and 'patchy' but sufficient to promote diapycnal mixing. The significance of this mixing process is further investigated by comparing our findings with long-term observations from the Liverpool Bay Coastal Observatory. We identify that the conditions for shear instability during SIPS are regularly met and suggest that this process contributes to the current underestimates of near coastal mixing observed in regional models. To assist our understanding of the observed processes and to test the current capability of turbulence 'closure schemes' we employ a one-dimensional numerical model to investigate the physical mechanisms driving diapycnal mixing in Liverpool Bay.
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Distribution and growth dynamics of ephemeral macroalgae in shallow bays on the Swedish west coast
NASA Astrophysics Data System (ADS)
Pihl, Leif; Magnusson, Gunilla; Isaksson, Ingela; Wallentinus, Inger
1996-02-01
Distribution and growth dynamics of ephemeral macroalgae were investigated in some shallow (0-1 m) bays on the Swedish west coast during the period 1992 to 1994. Variation in cover and biomass was assessed in nine bays, and in one of them the seasonal dynamics of these algae was followed intensively over three years. Frequent measurements were taken of algal biomass, degree of cover, in situ growth, variable fluorescence and C/N-ratios. Irradiance and water nutrient concentrations were measured concurrently with the growth measurements. Ephemeral macroalgae were dominated by Cladophora and Enteromorpha species and occurred in all sampled bays, except one, covering 10 to 100% of the bottom sediment. Generally, a rapid biomass increase was recorded from mid-May, which peaked after six weeks at 400-600 g dwt·m -2. Later in the season, strong variations in biomass, cover and species composition were observed, suggesting that these opportunistic algae form a highly dynamic community. Initial growth rates estimated from biomass samples were similar to those recorded from in situ cage experiments, and also agreed with growth rates calculated from a model. For all species studied growth rate was within the range 10 to 30 g dwt·m -2·d -1, irrespective of method used. Low algal C/N-ratios (mean = 12.7) in 1993 (cold and rainy summer) indicated that growth was not limited by nutrients, but rather by light. In 1994 (warm and sunny summer), mean C/N-ratios were 20, reflecting the opposite situation. The appearance of these opportunistic algae in shallow bays which historically had been without macroalgal communities has changed the characteristics of these areas by altering habitat complexity. This could have important consequences for trophic interactions involving many species, thereby altering community structure and function.
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Ecosystem history of southern and central Biscayne Bay; summary report on sediment core analyses
Wingard, G.L.; Cronin, T. M.; Dwyer, G.S.; Ishman, S.E.; Willard, D.A.; Holmes, C.W.; Bernhardt, C.E.; Williams, C.P.; Marot, M.E.; Murray, J.B.; Stamm, R.G.; Murray, J.H.; Budet, C.
2003-01-01
During the last century, the environs of Biscayne Bay have been greatly affected by anthropogenic alteration through urbanization of the Miami/Dade County area. The sources, timing, delivery, and quality of freshwater flow into the Bay have been changed by construction of a complex canal system that controls movement of water throughout south Florida. Changes in shoreline and sub-aquatic vegetation and marine organisms have been observed and changes in water delivery are believed to be the cause. Current restoration goals are attempting to restore natural flow of fresh water into Biscayne and Florida Bays and to restore the natural fauna and flora, but first we need to determine pre-alteration baseline conditions in order to establish targets and performance measures for restoration. This research is part of an ongoing study designed to address the needs of the Biscayne Bay Coastal Wetlands Project (BBCW) of the Comprehensive Everglades Restoration Plan (CERP). By establishing the natural patterns of temporal change in salinity, water quality, vegetation, and benthic fauna in Biscayne Bay and the nearby wetlands over the last 100- 500 years the USGS, in collaboration with our partners, will provide the data necessary to set realistic targets to achieve the BBCW Project goals. Six cores from three sites in Biscayne Bay were collected in April 2002 for multidisciplinary multi-proxy analyses. This report details the results of these analyses and compares the 2002 cores to cores collected in 1997. The following are our significant findings to date: ?\tThe salinity of central Biscayne Bay has become increasingly marine and increasingly stable over the last 100 years. o\tAt No Name Bank, prior to approximately 1915, the inter-decadal and decadal salinity fluctuations appear to have been greater than after 1915 when salinities stabilized at that site. o\tContinental shelf/open marine influence on the sites has increased during the 20th century. o\tThere is no indication of inter-decadal salinity extremes or periods of hypersalinity. o\tFreshwater and mesohaline salinities have had a minor influence on No Name bank throughout the time of deposition. At Featherbed Bank, the influence is reduced to mesohaline salinities. ?\tCard Bank has experienced relatively large swings in salinity over multi-decadal and centennial timescales, compared to central Biscayne Bay, but marine influence at the site has increased over the last century. ?\tIndications of regional scale patterns have been found, especially in the shell chemistry data and the pollen assemblages. These regional patterns indicate that the changes are not site specific and may not be limited to Biscayne Bay. ?\tSub-aquatic vegetation has undergone bay-wide patterns of change over the last 200-500 years, which includes expansion prior to 1900 and declines during the last century in central Biscayne Bay. o\tThalassia appears to have increased at all three core sites sometime between 1550 and 1750 AD. o\tA decline in Thalassia appears to have occurred after 1950 at No Name Bank and slightly earlier in the 20th century at Featherbed Bank. o\tCard Bank does not appear to have experienced any declines in vegetation on an inter-decadal scale during the 20th century. ?\tMolluscan faunal abundance and diversity have undergone significant changes in central Biscayne Bay. ?\tIndicators of increased organic-rich sediments at No Name occur between 1869 to 1888 and between the 1930's to 1975. These changes may correlate to human activities (settlement, population growth). These findings represent a first step towards the project's goal to reconstruct the history of Biscayne Bay and they provide us with a working model to be tested at other sites. It is clear from our findings that Biscayne Bay has been a dynamic environment over the last 500 years, with natural changes occurring in salinity and benthic habitats. However, several significant changes have occurred in the 20th ce
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The Bridge Project: Connecting Home, School, and Community for Mexican Immigrant Children
ERIC Educational Resources Information Center
McElvain, Cheryl Marie
2015-01-01
This study examines the academic and psychosocial effects of the Bridge Project after-school program on 25 prekindergarten through 6th-grade English language learner Mexican immigrant children and their families living in an affordable housing complex in the San Francisco Bay Area. The results of the study show that the program increased the…
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Characterizing underwater habitat and other features is difficult and costly, especially in large river systems. The St. Louis River is the largest US tributary to Lake Superior and the lower portion consists of a 48.5 km2 complex of wetlands, tributaries, and bays. We surveyed 8...
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Interaction between a wildfire and the sea-breeze front
Deborah E. Hanley; Philip Cunningham; Scott Goodrick
2013-01-01
Florida experiences sea breezes, lake breezes, and bay breezes almost every day during the year, and there are frequently complex interactions between many of these breezes. Given the often-rapid changes in temperature, humidity, and wind speed that accompany these breezes, most wildfires and prescribed fires in Florida are affected in some way by their interaction...
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Characterizing underwater habitat and other features is difficult and costly, especially in large river systems. The St. Louis River is the largest US tributary to Lake Superior and the lower portion consists of a 48.5 km2 complex of wetlands, tributaries, and bays. We surveyed 8...
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Deep drilling into the Chesapeake Bay impact structure
Gohn, G.S.; Koeberl, C.; Miller, K.G.; Reimold, W.U.; Browning, J.V.; Cockell, C.S.; Horton, J. Wright; Kenkmann, T.; Kulpecz, A.A.; Powars, D.S.; Sanford, W.E.; Voytek, M.A.
2008-01-01
Samples from a 1.76-kilometer-deep corehole drilled near the center of the late Eocene Chesapeake Bay impact structure (Virginia, USA) reveal its geologic, hydrologic, and biologic history. We conducted stratigraphic and petrologic analyses of the cores to elucidate the timing and results of impact-melt creation and distribution, transient-cavity collapse, and ocean-water resurge. Comparison of post-impact sedimentary sequences inside and outside the structure indicates that compaction of the crater fill influenced long-term sedimentation patterns in the mid-Atlantic region. Salty connate water of the target remains in the crater fill today, where it poses a potential threat to the regional groundwater resource. Observed depth variations in microbial abundance indicate a complex history of impact-related thermal sterilization and habitat modification, and subsequent post-impact repopulation.
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2004-03-26
CAPE CANAVERAL, Fla. -- This aerial photo shows the expanse of the Launch Complex 39 Area, bordered on the east by the Atlantic Ocean and cloud-filled sky. At center right, towering above the surrounding sites, is the Vehicle Assembly Building. To the left, or north, is the Orbiter Processing Facility’s Bay 3. On the western side are OPF Bays 1 and 2. In the lower right corner is the Operations Support Building. The two-lane crawlerway stretches from the VAB toward the coast, site of Launch Pad 39A, closest, and Launch Pad 39B, far left. Between the VAB and the ocean sprawl the Banana Creek and the Banana River. The turn basin, at right, allows delivery of external tanks that are offloaded close to and transported to the VAB. Photo credit: NASA
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2012-04-27
CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, cable trays wind their way along the grating in high bay 3 in the Vehicle Assembly Building, or VAB, during part of a centerwide refurbishment initiative under the Ground Systems Development and Operations GSDO Program. The cable replacement project is under way in high bays 1 and 3 on the east side of the building, facing Launch Complex 39’s pads A and B. Approximately 150 miles of existing Apollo/shuttle era cabling is being removed to make room for installation of state-of-the-art command, communication and control systems that will be needed by future users to perform vehicle testing and verification prior to rollout to the launch pad. For more information, visit http://go.nasa.gov/groundsystems. Photo credit: NASA/Jim Grossmann
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2012-04-27
CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, old racks are being excessed in high bay 3 in the Vehicle Assembly Building, or VAB, as part of a centerwide refurbishment initiative under the Ground Systems Development and Operations GSDO Program The cable replacement project is under way in high bays 1 and 3 on the east side of the building, facing Launch Complex 39’s pads A and B. Approximately 150 miles of existing Apollo/shuttle era cabling is being removed to make room for installation of state-of-the-art command, communication and control systems that will be needed by future users to perform vehicle testing and verification prior to rollout to the launch pad. For more information, visit http://go.nasa.gov/groundsystems. Photo credit: NASA/Jim Grossmann
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2012-04-27
CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, old cabling is being pulled from high bay 3 in the Vehicle Assembly Building, or VAB, as part of a centerwide refurbishment initiative under the Ground Systems Development and Operations GSDO Program. The cable replacement project is under way in high bays 1 and 3 on the east side of the building, facing Launch Complex 39’s pads A and B. Approximately 150 miles of existing Apollo/shuttle era cabling is being removed to make room for installation of state-of-the-art command, communication and control systems that will be needed by future users to perform vehicle testing and verification prior to rollout to the launch pad. For more information, visit http://go.nasa.gov/groundsystems. Photo credit: NASA/Jim Grossmann
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2012-04-27
CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, cable trays run along the walls in high bay 3 in the Vehicle Assembly Building, or VAB, as part of a centerwide refurbishment initiative under the Ground Systems Development and Operations GSDO Program. The cable replacement project is under way in high bays 1 and 3 on the east side of the building, facing Launch Complex 39’s pads A and B. Approximately 150 miles of existing Apollo/shuttle era cabling is being removed to make room for installation of state-of-the-art command, communication and control systems that will be needed by future users to perform vehicle testing and verification prior to rollout to the launch pad. For more information, visit http://go.nasa.gov/groundsystems. Photo credit: NASA/Jim Grossmann
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Seitkalieva, Alexandra V; Menzorova, Natalie I; Rasskazov, Valerу A
2016-01-01
New phosphatase and DNase inhibition tests for assessing the total pollution of a natural marine ecosystem were applied. The seawater samples with different pollution degrees were collected in the Troitsa Bay of the Peter the Great Bay (the Sea of Japan). The sensitivity of the alkaline phosphatase test to integrated pollution was in accordance with the sensitivity of the standard sea urchin sperm cell toxicity test. The increased seawater pollution level was shown to result in an up to fourfold increase in specific activities of acid and alkaline phosphatases from the mussel Crenomytilus grayanus. It was demonstrated that a complex methodological approach can be used to assess marine water areas, as well as to assess the biological conditions of invertebrates adapting to different environmental and anthropogenic effects.
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Hydrocarbons in recent sediment of the Monterey Bay National Marine Sanctuary
Kvenvolden, K.A.; Hostettler, F.D.; Rosenbauer, R.W.; Lorenson, T.D.; Castle, W.T.; Sugarman, S.
2002-01-01
A complex mixture of hydrocarbons is present in the recent sediment of the Monterey Bay National Marine Sanctuary. Eighteen samples from the continental shelf between San Francisco and Monterey contain aliphatic and aromatic hydrocarbons showing biological contributions from both marine and terrigenous sources, with the terrigenous indicators more pronounced near Monterey. Of particular interest, however, is a low-level background of petroleum-related compounds, including 28,30-bisnorhopane and 18??+??(H)-oleanane, which are characteristic of many crude oils from the Monterey Formation of California. Thus, the sediments are overprinted by a regional chemical signature which may be derived from eroded Monterey Formation rocks and from onshore and offshore seeps releasing petroleum from Monterey Formation source rocks. ?? 2002 Elsevier Science B.V. All rights reserved.
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Deep drilling into the Chesapeake Bay impact structure.
Gohn, G S; Koeberl, C; Miller, K G; Reimold, W U; Browning, J V; Cockell, C S; Horton, J W; Kenkmann, T; Kulpecz, A A; Powars, D S; Sanford, W E; Voytek, M A
2008-06-27
Samples from a 1.76-kilometer-deep corehole drilled near the center of the late Eocene Chesapeake Bay impact structure (Virginia, USA) reveal its geologic, hydrologic, and biologic history. We conducted stratigraphic and petrologic analyses of the cores to elucidate the timing and results of impact-melt creation and distribution, transient-cavity collapse, and ocean-water resurge. Comparison of post-impact sedimentary sequences inside and outside the structure indicates that compaction of the crater fill influenced long-term sedimentation patterns in the mid-Atlantic region. Salty connate water of the target remains in the crater fill today, where it poses a potential threat to the regional groundwater resource. Observed depth variations in microbial abundance indicate a complex history of impact-related thermal sterilization and habitat modification, and subsequent post-impact repopulation.
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Earth Observations taken by the Expedition 10 crew
2004-11-12
ISS010-E-06681 (12 November 2004) --- Shark Bay, Australia is featured in this image photographed by an Expedition 10 crewmember on the International Space Station (ISS). This image shows large solar salt works developed in Useless Loop and Useless Inlet, Shark Bay, Western Australia. The salt (sodium chloride) is produced when ponds are repeatedly flooded with seawater, which is progressively concentrated by evaporation. This particular salt farm opened in 1967 and expanded operations in the 1990s. Today, this salt farm comprises over 50 ponds, the newest pond in the outermost pond in Useless Inlet, which provides the first evaporation cycle to increase the salinity of the water prior to entering the next pond. Complex chemical and biological adjustments occur in the system each time the configuration of ponds is changed.
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Re-examining Distal Facies of the Grand Bay Ignimbrite at Fond St. Jean, Dominica
NASA Astrophysics Data System (ADS)
Ebner, N.; Frey, H. M.; Wirth, K. R.; Waters, L. E.; Manon, M. R. F.
2017-12-01
The Grand Bay ignimbrite in southern Dominica is a relatively young (43 ± 13 ka by U-Th of zircon), voluminous (0-.5-1 km3 on-land) and laterally extensive pyroclastic flow deposit spanning over 20 km2 that has been associated with the Micotrin volcanic center or Plat Pays complex. The Grand Bay ignimbrite typically occurs as a massive valley fill facies, approximately 9-14 meters thick, exposed on the southern coastal road, rich in white-light gray, relatively crystal rich (25-31%) andesitic (62-63.5 wt% SiO2, 16.7 wt% Al2O3, 6.5 wt % Fe2O3) pumice, whose mineral assemblage is dominated by plagioclase (22-25%), orthopyroxene (3-4%), and clinopyroxene (1-1.5%), in an unconsolidated gray ashy matrix. In the literature, distal facies of the Grand Bay ignimbrite have been proposed at Fond St. Jean (FSJ), but this supposition has recently been called into question. The 9 m thick stratified Fond St. Jean ignimbrite, (38,890 k.a. ± 600 B.P. by14C), is weathered yellow orange and overlies a 4 m thick lithified beach deposit on a sharp contact. Andesitic pumice clasts (60.5-64.5 wt% SiO2, 18 wt% Al2O3, 5.5 wt % Fe2O3) from the base of the FSJ ignimbrite contain similar mineral assemblages to Grand Bay clasts, however, FSJ pumices are relatively less crystal-rich (16-19%), contain significantly less plagioclase (13-16%), opx (1.0-1.5%), cpx (0.1 - 0.6%), and, most strikingly, up to 1% hornblende, which was not present in any Grand Bay samples. The lowermost three meters of the FSJ ignimbrite sequence is composed of meter thick sections of clast (5-7 cm pumice and ≤1 cm lithics) supported beds (70 cm), grading upwards into 30 cm of ash laminations and small pumice clasts (1-3 cm). Following a 40 cm bed of massive ash containing 1-3 cm clasts of pumice, the initial sequence repeats itself for 5 meters, with 30-40 cm lithic blocks in the uppermost unit. In addition to the stark stratigraphic and petrographic differences from the Grand Bay Beach exposure, Fe-Ti oxide geothermometry reveals eruption temperature of 820 + 7°C at Grand Bay Beach (ΔNNO - 0.16) and 864 ± 33 °C (ΔNNO - 0.25) at Fond St. Jean. Plagioclase composition ranges from An51-88 at Grand Bay and An57-75 at Fond St. Jean respectively. Furthermore, plagioclase hygrometry shows a range of 7.8 to 7.3 wt% H2O at Grand Bay, with slightly drier conditions of 7.3 to 7.1 wt% H2O at Fond St. Jean.
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NASA Astrophysics Data System (ADS)
Wingard, G. L.; Cronin, T. M.; Dwyer, G. S.; Holmes, C. W.; Ishman, S. E.
2003-12-01
The south Florida ecosystem has undergone profound changes during the last century as a result of urbanization, agricultural development, and the construction of a massive water control system - the Central and Southern Florida (C&SF) Project. Created in 1948, the C&SF Project was designed for flood protection and to provide water for people and agricultural development. The extensive network of canals, levees, and water-control structures cover over 18,000 square miles and have completely altered the natural sheet flow of water across the land. Water was, and is, the principal driving force of this unique subtropical ecosystem, a significant portion of which is public land, including Everglades National Park, Biscayne National Park, Big Cypress National Preserve, the Florida Keys National Marine Sanctuary, Dry Tortugas National Park, and six National Wildlife Refuge Complexes. The Comprehensive Everglades Restoration Plan (CERP) has been designed in an effort to restore more natural water delivery to the ecosystem. This plan will cost over 8 billion dollars and take more than 30 years to complete. To successfully implement the CERP, land managers and restoration planners need answers to questions such as what are our restoration targets? What conditions are we restoring the system to? What portion of the changes seen in the 20th century can be attributed to land-use changes and what portion to natural change? What are the impacts on living resources? Paleoecologic and biochemical research is providing the answers to these questions. Analyses of cores from Florida Bay and Biscayne Bay have highlighted the following important findings. (1) Although land-use changes have played a role in determining salinity for Florida Bay as a whole, salinity is more strongly correlated to rainfall than any other single factor. (2) Anthropogenic activity influences the magnitude of salinity variations seen in recent times in Florida Bay, and they probably act on a local basis to influence salinity patterns near areas of canal outflow. (3) Declines in species diversity and increases in dominance of salinity-tolerant species have occurred since the 1980s in several benthic invertebrate groups in different regions of Florida Bay. (4) Increases in abundance and/or density of sub-aquatic vegetation appear to have occurred in the last 50 years, compared to the first half of the 20th century. 5) In central Biscayne Bay salinities have become increasingly marine and increasingly stable over the last century. (6) Southern Biscayne Bay has experienced relatively large swings in salinity over multi-decadal and centennial timescales, but marine influence at the site has increased over the last century. (7) Sub-aquatic vegetation in Biscayne Bay has undergone bay-wide patterns of change over the last 200-500 years but a decline in Thalassia appears to have occurred in central Biscayne Bay around the middle of the 20th century. These findings are providing land management agencies with the information they need to plan and prioritize restoration effectively.
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-05-28
...-AA08 Special Local Regulation; Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay... Lighthouse Dock, Fire Island, NY due to the annual Maggie Fischer Memorial Great South Bay Cross Bay Swim..., Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, NY, in the Federal Register (74...
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Presser, Theresa S.; Luoma, Samuel N.
2006-01-01
Selenium discharges to the San Francisco Bay-Delta Estuary (Bay-Delta) could change significantly if federal and state agencies (1) approve an extension of the San Luis Drain to convey agricultural drainage from the western San Joaquin Valley to the North Bay (Suisun Bay, Carquinez Strait, and San Pablo Bay); (2) allow changes in flow patterns of the lower San Joaquin River and Bay-Delta while using an existing portion of the San Luis Drain to convey agricultural drainage to a tributary of the San Joaquin River; or (3) revise selenium criteria for the protection of aquatic life or issue criteria for the protection of wildlife. Understanding the biotransfer of selenium is essential to evaluating effects of selenium on Bay-Delta ecosystems. Confusion about selenium threats to fish and wildlife stem from (1) monitoring programs that do not address specific protocols necessary for an element that bioaccumulates; and (2) failure to consider the full complexity of the processes that result in selenium toxicity. Past studies show that predators are more at risk from selenium contamination than their prey, making it difficult to use traditional methods to predict risk from environmental concentrations alone. This report presents an approach to conceptualize and model the fate and effects of selenium under various load scenarios from the San Joaquin Valley. For each potential load, progressive forecasts show resulting (1) water-column concentration; (2) speciation; (3) transformation to particulate form; (4) particulate concentration; (5) bioaccumulation by invertebrates; (6) trophic transfer to predators; and (7) effects on those predators. Enough is known to establish a first-order understanding of relevant conditions, biological response, and ecological risks should selenium be discharged directly into the North Bay through a conveyance such as a proposed extension of the San Luis Drain. The approach presented here, the Bay-Delta selenium model, determines the mass, fate, and effects of selenium released to the Bay-Delta through use of (1) historical land-use, drainage, alluvial-fill, and runoff databases; (2) existing knowledge concerning biogeochemical reactions and physiological parameters of selenium (e.g., speciation, partitioning between dissolved and particulate forms, and bivalve assimilation efficiency); and (3) site-specific data mainly from 1986 to 1996 for clams and bottom-feeding fish and birds. Selenium load scenarios consider effluents from North Bay oil refineries and discharges of agricultural drainage from the San Joaquin Valley to enable calculation of (a) a composite freshwater endmember selenium concentration at the head of the estuary; and (b) a selenium concentration at a selected seawater location (Carquinez Strait) as a foundation for modeling. Analysis of selenium effects also takes into account the mode of conveyance for agricultural drainage (i.e., the San Luis Drain or San Joaquin River); and flows of the Sacramento River and San Joaquin River on a seasonal or monthly basis. Load scenarios for San Joaquin Valley mirror predictions made since 1955 of a worsening salt (and by inference, selenium) build-up exacerbated by an arid climate and massive irrigation. The reservoir of selenium in the San Joaquin Valley is sufficient to provide loading at an annual rate of approximately 42,500 pounds of selenium to a Bay-Delta disposal point for 63 to 304 years at the lower range of projections presented here, even if influx of selenium from the California Coast Ranges could be curtailed. Disposal of wastewaters on an annual basis outside of the San Joaquin Valley may slow the degradation of valley resources, but drainage alone cannot alleviate the salt and selenium build-up in the San Joaquin Valley, at least within a century. Load scenarios also show the different proportions of selenium loading to the Bay-Delta. Oil refinery loads from 1986 to 1992 ranged from 8.5 to 20 pounds of selenium per day;
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NASA Astrophysics Data System (ADS)
Rates, Christopher A.; Mulvey, Bridget K.; Feldon, David F.
2016-08-01
Components of complex systems apply across multiple subject areas, and teaching these components may help students build unifying conceptual links. Students, however, often have difficulty learning these components, and limited research exists to understand what types of interventions may best help improve understanding. We investigated 32 high school students' understandings of complex systems components and whether an agent-based simulation could improve their understandings. Pretest and posttest essays were coded for changes in six components to determine whether students showed more expert thinking about the complex system of the Chesapeake Bay watershed. Results showed significant improvement for the components Emergence ( r = .26, p = .03), Order ( r = .37, p = .002), and Tradeoffs ( r = .44, p = .001). Implications include that the experiential nature of the simulation has the potential to support conceptual change for some complex systems components, presenting a promising option for complex systems instruction.
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Scientific Guidance for Rehabilitation of the Chesapeake Bay Ecosystem under the Changing Climate.
NASA Astrophysics Data System (ADS)
Boesch, D. F.; Johnson, Z. P.; Li, M.
2017-12-01
While the Chesapeake Bay is an estuary and not a marginal sea on the scale of the Baltic Sea or the Gulf of Mexico, it has a complex set of environmental issues and multiple political jurisdictions such that it can serve as a test bed for science-informed management in larger marine systems. In particular, the Chesapeake Bay possesses a relatively advanced effort to ameliorate eutrophication, reduce toxic stresses, rehabilitate critical habitats, and sustainably utilized resources. Furthermore, both scientists and managers are addressing these challenges while now beginning to incorporate the effects of changes in temperature, precipitation and runoff, sea level, ocean boundary conditions, and pH. Increases in temperature and sea level are already apparent and future conditions can be estimated from global model projections, although sea level and ocean exchanges are also affected by variations in Gulf Stream flows and mesoscale climate. Changes in the volume, seasonality and variability in freshwater delivery from the multiple rivers discharging to the bay are harder to project with confidence, but may have pervasive consequences for circulation, reducing nutrient loads to ameliorate eutrophication, biogeochemical processes, and biotic distributions and dynamics. Science is now challenged to inform multiple adaptation strategies, including minimizing the vulnerability of humans and infrastructure, sustaining important tidal wetlands, managing sediment resources, sustaining living resources, redefining achievable ecosystem rehabilitation goals, and achieving shifting goals for nutrient load reductions. At the same time, science will also have to identify effective means to meet these challenges while also reducing greenhouse gas emissions.
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Bay Ridge Gardens - Mixed-Humid Affordable Multifamily Housing Deep Energy Retrofit
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lyons, J.; Moore, M.; Thompson, M.
2013-08-01
Under this project, Newport Partners (as part of the BA-PIRC research team) evaluated the installation, measured performance, and cost-effectiveness of efficiency upgrade measures for a tenant-in-place DER at the Bay Ridge multifamily (MF) development in Annapolis, Maryland. The design and construction phase of the Bay Ridge project was completed in August 2012. This report summarizes system commissioning, short-term test results, utility bill data analysis, and analysis of real-time data collected over a one-year period after the retrofit was complete. The Bay Ridge project is comprised of a 'base scope' retrofit which was estimated to achieve a 30%+ savings (relative tomore » pre-retrofit) on 186 apartments, and a 'DER scope' which was estimated to achieve 50% savings (relative to pre-retrofit) on a 12-unit building. The base scope was applied to the entire apartment complex, except for one 12-unit building which underwent the DER scope. A wide range of efficiency measures was applied to pursue this savings target for the DER building, including improvements/replacements of mechanical equipment and distribution systems, appliances, lighting and lighting controls, the building envelope, hot water conservation measures, and resident education. The results of this research build upon the current body of knowledge of multifamily retrofits. Towards this end, the research team has collected and generated data on the selection of measures, their estimated performance, their measured performance, and risk factors and their impact on potential measures.« less
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An assessment of butyltins and metals in sediment cores from the St. Thomas East End Reserves, USVI.
Hartwell, S Ian; Apeti, Dennis A; Mason, Andrew L; Pait, Anthony S
2016-11-01
Tributyltin (TBT) concentrations near a marina complex in Benner Bay on St. Thomas, US Virgin Islands, were elevated relative to other areas in a larger study of the southeastern shore of the island. At the request of the USVI Coastal Zone Management Program, sediment cores and surface sediment samples were collected to better define the extent and history of TBT deposition in the vicinity of Benner Bay. The sediment cores were sectioned into 2-cm intervals and dated with 210 Pb and 137 Cs. The core sections and the surface samples were analyzed for butyltins and 16 elements. Deposition rates varied from 0.07-5.0 mm/year, and were highest in the marina complex. Core ages ranged from 54 to 200 years. The bottoms of the cores contained shell hash, but the top layers all consisted of much finer material. Surface concentrations of TBT exceeded 2000 ng Sn/g (dry weight) at two locations. At a depth of 8 cm TBT exceeded 8800 ng Sn/g in the marina complex sediment. Based on the ratio of tributyltin to total butyltins, it appears that the marina sediments are the source of contamination of the surrounding area. There is evidence that vessels from neighboring islands may also be a source of fresh TBT. Copper concentrations increase over time up to the present. Gradients of virtually all metals and metalloids extended away from the marina complex. NOAA sediment quality guidelines were exceeded for As, Pb, Cu, Zn, and Hg.
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Biodegradation of crude oil in Arctic subsurface water from the Disko Bay (Greenland) is limited.
Scheibye, Katrine; Christensen, Jan H; Johnsen, Anders R
2017-04-01
Biological degradation is the main process for oil degradation in a subsurface oil plume. There is, however, little information on the biodegradation potential of Arctic, marine subsurface environments. We therefore investigated oil biodegradation in microcosms at 2 °C containing Arctic subsurface seawater from the Disko Bay (Greenland) and crude oil at three concentrations of 2.5-10 mg/L. Within 71 days, the total petroleum hydrocarbon concentration decreased only by 18 ± 18% for an initial concentration of 5 mg/L. The saturated alkanes nC13-nC30 and the isoprenoids iC18-iC21 were biodegraded at all concentrations indicating a substantial potential for biodegradation of these compound classes. Polycyclic aromatic compounds (PACs) disappeared from the oil phase, but dissolution was the main process of removal. Analysis of diagnostic ratios indicated almost no PAC biodegradation except for the C1-naphthalenes. To conclude, the marine subsurface microorganisms from the Disko Bay had the potential for biodegradation of n-alkanes and isoprenoids while the metabolically complex and toxic PACs and their alkylated homologs remained almost unchanged. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Recording ground motions where people live
NASA Astrophysics Data System (ADS)
Cranswick, E.; Gardner, B.; Hammond, S.; Banfill, R.
The 1989 Loma Prieta, Calif., earthquake caused spectacular damage to structures up to 100 km away in the San Francisco Bay sedimentary basin, including the Cypress Street viaduct overpass, the Bay Bridge, and buildings in the San Francisco Marina district. Although the few mainshock ground motions recorded in the northern San Francisco Bay area were “significantly larger … than would be expected from the pre-existing data set,” none were recorded at the sites of these damaged structures [Hanks and Krawinkler, 1991].Loma Prieta aftershocks produced order-of-magnitude variations of ground motions related to sedimentary basin response over distances of 1-2 km and less [Cranswick et al., 1990]. In densely populated neighborhoods, these distances can encompass the residences of thousands of people, but it is very unlikely that these neighborhoods are monitored by even one seismograph. In the last decade, the complexity of computer models used to simulate high-frequency ground motions has increased by several orders of magnitude [e.g., Frankel and Vidale, 1992], but the number of seismograph stations—hence, the spatial density of the sampling of ground motion data—has remained relatively unchanged. Seismologists must therefore infer the nature of the ground motions in the great unknown regions between observation points.
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Bio-Optical and Remote Sensing Observations in Chesapeake Bay. Chapter 7
NASA Technical Reports Server (NTRS)
Harding, Lawrence W., Jr.; Magnuson, Andrea
2003-01-01
The high temporal and spatial resolution of satellite ocean color observations will prove invaluable for monitoring the health of coastal ecosystems where physical and biological variability demands sampling scales beyond that possible by ship. However, ocean color remote sensing of Case 2 waters is a challenging undertaking due to the optical complexity of the water. The focus of this SIMBIOS support has been to provide in situ optical measurements from Chesapeake Bay (CB) and adjacent mid-Atlantic bight (MAB) waters for use in algorithm development and validation efforts to improve the satellite retrieval of chlorophyll (chl a) in Case 2 waters. CB provides a valuable site for validation of data from ocean color sensors for a number of reasons. First, the physical dimensions of the Bay (> 6,500 km2) make retrievals from satellites with a spatial resolution of approx. 1 km (i.e., SeaWiFS) or less (i.e., MODIS) reasonable for most of the ecosystem. Second, CB is highly influenced by freshwater flow from major rivers, making it a classic Case 2 water body with significant concentrations of chlorophyll, particulates and chromophoric dissolved organic matter (CDOM) that highly impact the shape of reflectance spectra.
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2004-03-26
CAPE CANAVERAL, Fla. -- The 525-foot high Vehicle Assembly Building dominates the Launch Complex 39 Area. On the right is the Launch Control Center. To the left are the Orbiter Processing Facility Bays 1, 2 and 3. At lower left is the Operation Support Building at lower right is the construction area for Operations Support Building 2. Behind the VAB meanders the Banana Creek. Photo credit: NASA
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Rapid assessment of wildfire damage using Forest Inventory data: A case in Georgia
Richard A. Harper; John W. Coulsten; Jeffery A. Turner
2009-01-01
The rapid assessment of damage caused by natural disasters is essential for planning the appropriate amount of disaster relief funds and public communication. Annual Forest Inventory and Analysis (FIA) data provided initial estimates of damage to timberland in a timely manner to State leaders during the 2007 Georgia Bay Complex Wildfire in southeast Georgia. FIA plots...
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The 1993 Shuttle Small Payloads Symposium
NASA Technical Reports Server (NTRS)
Thomas, Lawrence R. (Editor); Mosier, Frances L. (Editor)
1993-01-01
The 1993 Shuttle Small Payloads Symposium is a combined symposia of the Get Away Special (GAS), Hitchhiker, and Complex Autonomous Payloads (CAP) programs, and is proposed to continue as an annual conference. The focus of this conference is to educate potential Space Shuttle Payload Bay users as to the types of carrier systems provided and for current users to share experiment concepts.
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Nishino, Jo; Kochi, Yuta; Shigemizu, Daichi; Kato, Mamoru; Ikari, Katsunori; Ochi, Hidenori; Noma, Hisashi; Matsui, Kota; Morizono, Takashi; Boroevich, Keith A.; Tsunoda, Tatsuhiko; Matsui, Shigeyuki
2018-01-01
Genome-wide association studies (GWAS) suggest that the genetic architecture of complex diseases consists of unexpectedly numerous variants with small effect sizes. However, the polygenic architectures of many diseases have not been well characterized due to lack of simple and fast methods for unbiased estimation of the underlying proportion of disease-associated variants and their effect-size distribution. Applying empirical Bayes estimation of semi-parametric hierarchical mixture models to GWAS summary statistics, we confirmed that schizophrenia was extremely polygenic [~40% of independent genome-wide SNPs are risk variants, most within odds ratio (OR = 1.03)], whereas rheumatoid arthritis was less polygenic (~4 to 8% risk variants, significant portion reaching OR = 1.05 to 1.1). For rheumatoid arthritis, stratified estimations revealed that expression quantitative loci in blood explained large genetic variance, and low- and high-frequency derived alleles were prone to be risk and protective, respectively, suggesting a predominance of deleterious-risk and advantageous-protective mutations. Despite genetic correlation, effect-size distributions for schizophrenia and bipolar disorder differed across allele frequency. These analyses distinguished disease polygenic architectures and provided clues for etiological differences in complex diseases. PMID:29740473
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Ideal AFROC and FROC observers.
Khurd, Parmeshwar; Liu, Bin; Gindi, Gene
2010-02-01
Detection of multiple lesions in images is a medically important task and free-response receiver operating characteristic (FROC) analyses and its variants, such as alternative FROC (AFROC) analyses, are commonly used to quantify performance in such tasks. However, ideal observers that optimize FROC or AFROC performance metrics have not yet been formulated in the general case. If available, such ideal observers may turn out to be valuable for imaging system optimization and in the design of computer aided diagnosis techniques for lesion detection in medical images. In this paper, we derive ideal AFROC and FROC observers. They are ideal in that they maximize, amongst all decision strategies, the area, or any partial area, under the associated AFROC or FROC curve. Calculation of observer performance for these ideal observers is computationally quite complex. We can reduce this complexity by considering forms of these observers that use false positive reports derived from signal-absent images only. We also consider a Bayes risk analysis for the multiple-signal detection task with an appropriate definition of costs. A general decision strategy that minimizes Bayes risk is derived. With particular cost constraints, this general decision strategy reduces to the decision strategy associated with the ideal AFROC or FROC observer.
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Integrative genetic risk prediction using non-parametric empirical Bayes classification.
Zhao, Sihai Dave
2017-06-01
Genetic risk prediction is an important component of individualized medicine, but prediction accuracies remain low for many complex diseases. A fundamental limitation is the sample sizes of the studies on which the prediction algorithms are trained. One way to increase the effective sample size is to integrate information from previously existing studies. However, it can be difficult to find existing data that examine the target disease of interest, especially if that disease is rare or poorly studied. Furthermore, individual-level genotype data from these auxiliary studies are typically difficult to obtain. This article proposes a new approach to integrative genetic risk prediction of complex diseases with binary phenotypes. It accommodates possible heterogeneity in the genetic etiologies of the target and auxiliary diseases using a tuning parameter-free non-parametric empirical Bayes procedure, and can be trained using only auxiliary summary statistics. Simulation studies show that the proposed method can provide superior predictive accuracy relative to non-integrative as well as integrative classifiers. The method is applied to a recent study of pediatric autoimmune diseases, where it substantially reduces prediction error for certain target/auxiliary disease combinations. The proposed method is implemented in the R package ssa. © 2016, The International Biometric Society.
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Izzaty Horsali, Nurul Amira; Mat Zauki, Nurul Ashikin; Otero, Viviana; Nadzri, Muhammad Izuan; Ibrahim, Sulong; Husain, Mohd-Lokman; Dahdouh-Guebas, Farid
2018-01-01
Brunei Bay, which receives freshwater discharge from four major rivers, namely Limbang, Sundar, Weston and Menumbok, hosts a luxuriant mangrove cover in East Malaysia. However, this relatively undisturbed mangrove forest has been less scientifically explored, especially in terms of vegetation structure, ecosystem services and functioning, and land-use/cover changes. In the present study, mangrove areal extent together with species composition and distribution at the four notified estuaries was evaluated through remote sensing (Advanced Land Observation Satellite—ALOS) and ground-truth (Point-Centred Quarter Method—PCQM) observations. As of 2010, the total mangrove cover was found to be ca. 35,183.74 ha, of which Weston and Menumbok occupied more than two-folds (58%), followed by Sundar (27%) and Limbang (15%). The medium resolution ALOS data were efficient for mapping dominant mangrove species such as Nypa fruticans, Rhizophora apiculata, Sonneratia caseolaris, S. alba and Xylocarpus granatum in the vicinity (accuracy: 80%). The PCQM estimates found a higher basal area at Limbang and Menumbok—suggestive of more mature vegetation, compared to Sundar and Weston. Mangrove stand structural complexity (derived from the complexity index) was also high in the order of Limbang > Menumbok > Sundar > Weston and supporting the perspective of less/undisturbed vegetation at two former locations. Both remote sensing and ground-truth observations have complementarily represented the distribution of Sonneratia spp. as pioneer vegetation at shallow river mouths, N. fruticans in the areas of strong freshwater discharge, R. apiculata in the areas of strong neritic incursion and X. granatum at interior/elevated grounds. The results from this study would be able to serve as strong baseline data for future mangrove investigations at Brunei Bay, including for monitoring and management purposes locally at present. PMID:29479500
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Transport processes near coastal ocean outfalls
Noble, M.A.; Sherwood, C.R.; Lee, Hooi-Ling; Xu, Jie; Dartnell, P.; Robertson, G.; Martini, M.
2001-01-01
The central Southern California Bight is an urbanized coastal ocean where complex topography and largescale atmospheric and oceanographic forcing has led to numerous sediment-distribution patterns. Two large embayments, Santa Monica and San Pedro Bays, are connected by the short, very narrow shelf off the Palos Verdes peninsula. Ocean-sewage outfalls are located in the middle of Santa Monica Bay, on the Palos Verdes shelf and at the southeastern edge of San Pedro Bay. In 1992, the US Geological Survey, together with allied agencies, began a series of programs to determine the dominant processes that transport sediment and associated pollutants near the three ocean outfalls. As part of these programs, arrays of instrumented moorings that monitor currents, waves, water clarity, water density and collect resuspended materials were deployed on the continental shelf and slope information was also collected on the sediment and contaminant distributions in the region. The data and models developed for the Palos Verdes shelf suggest that the large reservoir of DDT/DDE in the coastal ocean sediments will continue to be exhumed and transported along the shelf for a long time. On the Santa Monica shelf, very large internal waves, or bores, are generated at the shelf break. The near-bottom currents associated with these waves sweep sediments and the associated contaminants from the shelf onto the continental slope. A new program underway on the San Pedro shelf will determine if water and contaminants from a nearby ocean outfall are transported to the local beaches by coastal ocean processes. The large variety of processes found that transport sediments and contaminants in this small region of the continental margin suggest that in regions with complex topography, local processes change markedly over small spatial scales. One cannot necessarily infer that the dominant transport processes will be similar even in adjacent regions.
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Nevers, M.B.; Shively, D.A.; Kleinheinz, G.T.; McDermott, C.M.; Schuster, W.; Chomeau, V.; Whitman, R.L.
2009-01-01
To determine more accurately the real-time concentration of fecal indicator bacteria (FIB) in beach water, predictive modeling has been applied in several locations around the Great Lakes to individual or small groups of similar beaches. Using 24 beaches in Door County, Wisconsin, we attempted to expand predictive models to multiple beaches of complex geography. We examined the importance of geographic location and independent variables and the consequential limitations for potential beach or beach group models. An analysis of Escherichia coli populations over 4 yr revealed a geographic gradient to the beaches, with mean E. coli concentrations decreasing with increasing distance from the city of Sturgeon Bay. Beaches grouped strongly by water type (lake, bay, Sturgeon Bay) and proximity to one another, followed by presence of a storm or creek outfall or amount of shoreline enclosure. Predictive models developed for beach groups commonly included wave height and cumulative 48-h rainfall but generally explained little E. coli variation (adj. R2 = 0.19-0.36). Generally low concentrations of E. coli at the beaches influenced the effectiveness of model results presumably because of low signal-to-noise ratios and the rarity of elevated concentrations. Our results highlight the importance of the sensitivity of regressors and the need for careful methods evaluation. Despite the attractiveness of predictive models as an alternative beach monitoring approach, it is likely that FIB fluctuations at some beaches defy simple prediction approaches. Regional, multi-beach, and individual beach predictive models should be explored alongside other techniques for improving monitoring reliability at Great Lakes beaches. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.
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Ribic, C.A.; Chapman, E.; Fraser, William R.; Lawson, G.L.; Wiebe, P.H.
2008-01-01
A key hypothesis guiding the US Southern Ocean Global Ocean Ecosystems Dynamics (US SO GLOBEC) program is that deep across-shelf troughs facilitate the transport of warm and nutrient-rich waters onto the continental shelf of the Western Antarctic Peninsula, resulting in enhanced winter production and prey availability to top predators. We tested aspects of this hypothesis during austral winter by assessing the distribution of the resident pack-ice top predators in relation to these deep across-shelf troughs and by investigating associations between top predators and their prey. Surveys were conducted July-August 2001 and August-September 2002 in Marguerite Bay, Antarctica, with a focus on the main across-shelf trough in the bay, Marguerite Trough. The common pack-ice seabird species were snow petrel (Pagodroma nivea, 1.2 individuals km-2), Antarctic petrel (Thalassoica antarctica, 0.3 individuals km-2), and Ade??lie penguin (Pygoscelis adeliae, 0.5 individuals km-2). The most common pack-ice pinniped was crabeater seal (Lobodon carcinophagus). During both winters, snow and Antarctic petrels were associated with low sea-ice concentrations independent of Marguerite Trough, while Ade??lie penguins occurred in association with this trough. Krill concentrations, both shallow and deep, also were associated with Ade??lie penguin and snow petrel distributions. During both winters, crabeater seal occurrence was associated with deep krill concentrations and with regions of lower chlorophyll concentration. The area of lower chlorophyll concentrations occurred in an area with complex bathymetry close to land and heavy ice concentrations. Complex or unusual bathymetry via its influence on physical and biological processes appears to be one of the keys to understanding how top predators survive during the winter in this Antarctic region. ?? 2007 Elsevier Ltd. All rights reserved.
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33 CFR 100.124 - Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York.
Code of Federal Regulations, 2011 CFR
2011-07-01
... South Bay Cross Bay Swim, Great South Bay, New York. 100.124 Section 100.124 Navigation and Navigable... NAVIGABLE WATERS § 100.124 Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York. (a) Regulated area. All navigable waters of Great South Bay, NY within a 100 yard radius of each...
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Carbonate system biogeochemistry in a subterranean estuary - Waquoit Bay, USA
NASA Astrophysics Data System (ADS)
Liu, Qian; Charette, Matthew A.; Breier, Crystaline F.; Henderson, Paul B.; McCorkle, Daniel C.; Martin, William; Dai, Minhan
2017-04-01
Quantifying carbon fluxes associated with submarine groundwater discharge (SGD) remains challenging due to the complex biogeochemistry of the carbonate system in the subterranean estuary (STE). Here we conducted time series measurements of total alkalinity (TAlk) and dissolved inorganic carbon (DIC) in a well-studied coastal aquifer (Waquoit Bay, Massachusetts, USA). Groundwater samples were collected monthly from May 2009 to June 2010 across the freshwater-saltwater mixing zone of the Waquoit Bay (WB) STE. The concentrations of both TAlk and DIC in zero-salinity groundwater were variable, but were lower than those in the bay water (S ∼ 28). DIC underwent slightly non-conservative mixing between low and intermediate salinities while there was an apparent additional DIC source at high salinity (>20) in all seasons. TAlk concentrations exhibited even stronger variations, with evidence of both production and consumption in high salinity zones, and consistent TAlk consumption at intermediate salinity in summer and fall (June-December, 2009). The increases in DIC and TAlk at high salinity were attributed to aerobic respiration and denitrification in WB sediments during bay water recharge of the STE. We infer that the loss of TAlk at intermediate salinity reflects H+ production as reduced compounds (e.g. Fe2+) are oxidized within the STE. In terms of impacts on surface water inorganic carbon budgets, the SGD-derived DIC flux was mainly controlled by seasonal changes in SGD while a combination of TAlk concentration variability and SGD drove the TAlk flux. SGD-derived DIC, aqueous CO2, and H+ fluxes to the bay were ∼40-50% higher in summer vs. in winter, a result of enhanced marine groundwater flux and significant TAlk removal (proton addition) during periods of high seawater intrusion. Furthermore, the SGD-derived DIC flux was consistently greater than TAlk flux regardless of season, indicating that SGD serves to reduce the CO2 buffering capacity of surface water. Our results highlight the importance of seasonality and subsurface biogeochemical processes on the subterranean estuary carbonate system and the resulting impact on SGD-derived TAlk, DIC, aqueous CO2, and H+ fluxes to the coastal ocean.
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Impacts of Storm Surge Mitigation Strategies on Aboveground Storage Tank Chemical Spill Transport
NASA Astrophysics Data System (ADS)
Do, C.; Bass, B. J.; Bernier, C.; Samii, A.; Dawson, C.; Bedient, P. B.
2017-12-01
The Houston Ship Channel (HSC), located in the hurricane-prone Houston-Galveston region of the upper Texas Coast, is one of the busiest waterways in the United States and is home to one of the largest petrochemical complexes in the world. Due to the proximity of the HSC to Galveston Bay and the Gulf of Mexico, chemical spills resulting from storm surge damage to aboveground storage tanks (ASTs) pose serious threats to the environment, residential communities, and national/international markets whose activities in the HSC generate billions of dollars annually. In an effort to develop a comprehensive storm surge mitigation strategy for Galveston Bay and its constituents, Rice University's Severe Storm Prediction, Education, and Evacuation from Disasters Center proposed two structural storm surge mitigation concepts, the Mid Bay Structure (MBS) and the Lower Bay Structure (LBS) as components of the Houston-Galveston Area Protection System (H-GAPS) project. The MBS consists of levees along the HSC and a navigational gate across the channel, and the LBS consists of a navigation gate and environmental gates across Bolivar Road. The impacts of these two barrier systems on the fate of AST chemical spills in the HSC have previously been unknown. This study applies the coupled 2D SWAN+ADCIRC model to simulate hurricane storm surge circulation within the Gulf of Mexico and Galveston Bay due to a synthetic storm which results in approximately 250-year surge levels in Galveston Bay. The SWAN+ADCIRC model is run using high-resolution computational meshes that incorporate the MBS and LBS scenarios, separately. The resulting wind and water velocities are then fed into a Lagrangian particle transport model to simulate the spill trajectories of the ASTs most likely to fail during the 250-year proxy storm. Results from this study illustrate how each storm surge mitigation strategy impacts the transport of chemical spills (modeled as Lagrangian particles) during storm surge as compared to the base case with only currently existing mitigation features in place. This study is part of a larger effort to evaluate the costs and benefits of several storm surge mitigation configurations proposed by the H-GAPS project.
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Overview of the Mars Science Laboratory mission: Bradbury Landing to Yellowknife Bay and beyond
NASA Astrophysics Data System (ADS)
Vasavada, A. R.; Grotzinger, J. P.; Arvidson, R. E.; Calef, F. J.; Crisp, J. A.; Gupta, S.; Hurowitz, J.; Mangold, N.; Maurice, S.; Schmidt, M. E.; Wiens, R. C.; Williams, R. M. E.; Yingst, R. A.
2014-06-01
The Mars Science Laboratory mission reached Bradbury Landing in August 2012. In its first 500 sols, the rover Curiosity was commissioned and began its investigation of the habitability of past and present environments within Gale Crater. Curiosity traversed eastward toward Glenelg, investigating a boulder with a highly alkaline basaltic composition, encountering numerous exposures of outcropping pebble conglomerate, and sampling aeolian sediment at Rocknest and lacustrine mudstones at Yellowknife Bay. On sol 324, the mission turned its focus southwest, beginning a year-long journey to the lower reaches of Mt. Sharp, with brief stops at the Darwin and Cooperstown waypoints. The unprecedented complexity of the rover and payload systems posed challenges to science operations, as did a number of anomalies. Operational processes were revised to include additional opportunities for advance planning by the science and engineering teams.
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Aerial photo shows Launch Complex 39 Area
NASA Technical Reports Server (NTRS)
2000-01-01
This aerial photo captures many of the facilities involved in Space Shuttle launches. At center is the Vehicle Assembly Building (VAB), with the Launch Control Center at its right. The curved road on the left in the photo is the newly restored crawlerway leading into the VAB high bay 2, where a mobile launcher platform/crawler-transporter sits. The road restoration and high bay 2 are part of KSC's Safe Haven project, enabling the storage of orbiters during severe weather. The crawlerway also extends from the east side out to the two launch pads, one visible close to the road on the left and one to the left of the VAB. In the distance is the Atlantic Ocean. To the right of the crawlerway is the turn basin, into which ships tow the barge for offloading new external tanks from Louisiana.
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2012-04-27
CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, cable is being pulled from the cable trays lining the walls of high bay 3 in the Vehicle Assembly Building, or VAB, as part of a centerwide refurbishment initiative under the Ground Systems Development and Operations GSDO Program. The cable replacement project is under way in high bays 1 and 3 on the east side of the building, facing Launch Complex 39’s pads A and B. Approximately 150 miles of existing Apollo/shuttle era cabling is being removed to make room for installation of state-of-the-art command, communication and control systems that will be needed by future users to perform vehicle testing and verification prior to rollout to the launch pad. For more information, visit http://go.nasa.gov/groundsystems. Photo credit: NASA/Jim Grossmann
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2012-04-27
CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, workers pull cables between the 26th and 29th floors of high bay 3 in the 525-foot-tall Vehicle Assembly Building, or VAB, during part of a centerwide refurbishment initiative under the Ground Systems Development and Operations GSDO Program. The cable replacement project is under way in high bays 1 and 3 on the east side of the building, facing Launch Complex 39’s pads A and B. Approximately 150 miles of existing Apollo/shuttle era cabling is being removed to make room for installation of state-of-the-art command, communication and control systems that will be needed by future users to perform vehicle testing and verification prior to rollout to the launch pad. For more information, visit http://go.nasa.gov/groundsystems. Photo credit: NASA/Jim Grossmann
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2012-04-27
CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, refurbishment of high bay 3 is under way in the Vehicle Assembly Building, or VAB, as part of a centerwide refurbishment initiative under the Ground Systems Development and Operations GSDO Program. It is 525 feet from the bay’s ceiling to the floor. The cable replacement project is under way in high bays 1 and 3 on the east side of the building, facing Launch Complex 39’s pads A and B. Approximately 150 miles of existing Apollo/shuttle era cabling is being removed to make room for installation of state-of-the-art command, communication and control systems that will be needed by future users to perform vehicle testing and verification prior to rollout to the launch pad. For more information, visit http://go.nasa.gov/groundsystems. Photo credit: NASA/Jim Grossmann
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2012-04-27
CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, workers remove cables between the 26th and 29th floors of high bay 3 in the 525-foot-tall Vehicle Assembly Building, or VAB, during part of a centerwide refurbishment initiative under the Ground Systems Development and Operations GSDO Program. The cable replacement project is under way in high bays 1 and 3 on the east side of the building, facing Launch Complex 39’s pads A and B. Approximately 150 miles of existing Apollo/shuttle era cabling is being removed to make room for installation of state-of-the-art command, communication and control systems that will be needed by future users to perform vehicle testing and verification prior to rollout to the launch pad. For more information, visit http://go.nasa.gov/groundsystems. Photo credit: NASA/Jim Grossmann
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2014-10-29
CAPE CANAVERAL, Fla. – Preparations are underway to tow two of the observatories, the lower stack, mini-stack number 1, for NASA's Magnetospheric Multiscale Observatory, or MMS, from the Building 2 south encapsulation bay to the Building 1 high bay at the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. The MMS upper stack, mini-stack number 2, is scheduled to arrive in about two weeks. MMS is a Solar Terrestrial Probes mission comprising four identically instrumented spacecraft that will use Earth’s magnetosphere as a laboratory to study the microphysics of three fundamental plasma processes: magnetic reconnection, energetic particle acceleration and turbulence. Launch aboard a United Launch Alliance Atlas V rocket from Space Launch Complex 41 on Cape Canaveral Air Force Station is targeted for March 12, 2015. To learn more about MMS, visit http://mms.gsfc.nasa.gov. Photo credit: NASA/Dan Casper
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A NAIVE BAYES SOURCE CLASSIFIER FOR X-RAY SOURCES
DOE Office of Scientific and Technical Information (OSTI.GOV)
Broos, Patrick S.; Getman, Konstantin V.; Townsley, Leisa K.
2011-05-01
The Chandra Carina Complex Project (CCCP) provides a sensitive X-ray survey of a nearby starburst region over >1 deg{sup 2} in extent. Thousands of faint X-ray sources are found, many concentrated into rich young stellar clusters. However, significant contamination from unrelated Galactic and extragalactic sources is present in the X-ray catalog. We describe the use of a naive Bayes classifier to assign membership probabilities to individual sources, based on source location, X-ray properties, and visual/infrared properties. For the particular membership decision rule adopted, 75% of CCCP sources are classified as members, 11% are classified as contaminants, and 14% remain unclassified.more » The resulting sample of stars likely to be Carina members is used in several other studies, which appear in this special issue devoted to the CCCP.« less
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Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false In the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Buzzards Bay approach. 167.103 Section 167.103 Navigation and Navigable... the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Buzzards Bay approach. (a) A separation...
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Code of Federal Regulations, 2012 CFR
2012-07-01
... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false In the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Narragansett Bay approach. 167.102 Section 167.102 Navigation and....102 In the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Narragansett Bay approach. (a) A...
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Code of Federal Regulations, 2012 CFR
2012-07-01
... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false In the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Buzzards Bay approach. 167.103 Section 167.103 Navigation and Navigable... the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Buzzards Bay approach. (a) A separation...
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Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false In the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Buzzards Bay approach. 167.103 Section 167.103 Navigation and Navigable... the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Buzzards Bay approach. (a) A separation...
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Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false In the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Narragansett Bay approach. 167.102 Section 167.102 Navigation and....102 In the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Narragansett Bay approach. (a) A...
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Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false In the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Narragansett Bay approach. 167.102 Section 167.102 Navigation and....102 In the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Narragansett Bay approach. (a) A...
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Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false In the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Buzzards Bay approach. 167.103 Section 167.103 Navigation and Navigable... the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Buzzards Bay approach. (a) A separation...
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Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false In the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Narragansett Bay approach. 167.102 Section 167.102 Navigation and....102 In the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Narragansett Bay approach. (a) A...
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4. Overall view of complex. Foundry (MN99B) at center. Main ...
4. Overall view of complex. Foundry (MN-99-B) at center. Main section of roundhouse (MN-99-A) at left. Machine shop section of roundhouse in center behind foundry. East end of air brake shop section of roundhouse to right of machine shop. Top of sand tower (MN-99-E) just visible above main section of roundhouse at far left. Photograph taken from second floor of office (MN-99-D). View to south. - Duluth & Iron Range Rail Road Company Shops, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN
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2012-09-20
CAPE CANAVERAL, Fla. – Inside Orbiter Processing Facility-2 at NASA’s Kennedy Space Center in Florida, space shuttle Atlantis’ payload bay doors are closed for the final time. The orbiter is undergoing final preparations for its transfer to the Kennedy Space Center Visitor complex targeted for November. The work is part of Transition and Retirement of the remaining shuttle. Atlantis is being prepared for public display at the visitor complex. Over the course of its 26-year career, Atlantis spent 293 days in space during 33 missions. For more information, visit http://www.nasa.gov/transition. Photo credit: NASA/Jim Grossmann
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2012-09-20
CAPE CANAVERAL, Fla. – Inside Orbiter Processing Facility-2 at NASA’s Kennedy Space Center in Florida, work will begin soon to close space shuttle Atlantis’ payload bay doors for the final time. The orbiter is undergoing final preparations for its transfer to the Kennedy Space Center Visitor complex targeted for November. The work is part of Transition and Retirement of the remaining shuttle. Atlantis is being prepared for public display at the visitor complex. Over the course of its 26-year career, Atlantis spent 293 days in space during 33 missions. For more information, visit http://www.nasa.gov/transition. Photo credit: NASA/Jim Grossmann
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33 CFR 100.124 - Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York. 100.124 Section 100.124 Navigation and Navigable... NAVIGABLE WATERS § 100.124 Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York...
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NASA Astrophysics Data System (ADS)
Oishi, Y.; Furumura, T.; Imamura, F.; Yamashita, K.; Sugawara, D.
2016-12-01
In this study, we investigate the response of bays to the tsunami of Nankai-trough earthquake based on tsunami simulations and demonstrate the possibility that sea-level oscillation of each bay, which is induced by an incident tsunami, interacts with those of other bays. Several major cities in Japan, including the capital, are located in the bays near the Nankai trough and it is assumed that these cities will be largely affected by the tsunamis caused by recurring large earthquakes at the trough. Therefore, it is very important for these populated cities to understand the mechanism and properties of the tsunami-induced oscillations that continue for a long time in bays to draw up evacuation plans. To investigate the response of bays for various tsunamis that may occur in the Nankai trough area, we distributed the tsunami sources that have the form of a 2-D Gaussian function around the Nankai trough. From simulations with these sources, it was found that strong oscillations of bay water occur when the source is located in the bay itself or when strong oscillations occur in other bays. For example, when the Tosa bay oscillates, the Tokyo bay that is 600 km away from the Tosa bay also oscillates. Among the bays around the Nankai trough, the Suruga bay, the deepest bay in Japan with a 2500-km depth, oscillates more strongly than other bays for most cases. To check the influence of the strong oscillations in the Suruga bay on other bays, we conducted tsunami simulations using a modified topography model in which the Suruga bay is artificially landfilled. As a consequence, the strength of oscillations in the adjacent bays are reduced by 20-30%, suggesting the large influence of the distinguished oscillation of the Suruga bay on these bays. We finally conducted tsunami simulations using the eleven Nankai-trough earthquake scenarios of the Central Disaster Prevention Council (CDPC) of Japan as tsunami sources, and the mutual relation regarding the strengths of oscillations among the bays around the Nankai trough was confirmed irrespective of the earthquake scenarios. The results of this study suggest that oscillations of the bays do not occur independently in each bay but simultaneously occur among the bays. More detailed characteristics of the response of the bays to the tsunamis in the Nankai-trough area will be discussed in the presentation.
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Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. ...
Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. HIGH BAY 3, EXTENSIBLE WORK PLATFORM E, ROOF PLAN, ARCHITECTURAL. Sheet 22 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL
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Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. ...
Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. HIGH BAY 3, EXTENSIBLE WORK PLATFORM D, 2ND FLOOR PLAN, ARCHITECTURAL. Sheet 38 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL
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Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. ...
Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. HIGH BAY 3, EXTENSIBLE WORK PLATFORM D, MAIN FLOOR PLAN, ARCHITECTURAL. Sheet 39 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL
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Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. ...
Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. HIGH BAY 3, EXTENSIBLE WORK PLATFORM E, MAIN FLOOR PLAN, ARCHITECTURAL. Sheet 23 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL
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Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. ...
Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. HIGH BAY 3, EXTENSIBLE WORK PLATFORM D, ROOF PLAN, ARCHITECTURAL. Sheet 36 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL
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Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. ...
Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. HIGH BAY 3, EXTENSIBLE WORK PLATFORM D, 3RD FLOOR PLAN, ARCHITECTURAL. Sheet 37 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL
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Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. ...
Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. HIGH BAY 3, EXTENSIBLE WORK PLATFORM B, MAIN FLOOR PLAN, ARCHITECTURAL. Sheet 30 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL
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Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. ...
Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. HIGH BAY 3, EXTENSIBLE WORK PLATFORM C, 2ND FLOOR PLAN, ARCHITECTURAL. Sheet 15 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL
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Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. ...
Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. HIGH BAY 3, EXTENSIBLE WORK PLATFORM C, ROOF PLAN, ARCHITECTURAL. Sheet 14 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL
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Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. ...
Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. HIGH BAY 3, EXTENSIBLE WORK PLATFORM B, ROOF PLAN, ARCHITECTURAL. Sheet 28 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL
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Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. ...
Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. HIGH BAY 3, EXTENSIBLE WORK PLATFORM C, MAIN FLOOR PLAN, ARCHITECTURAL. Sheet 16 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL
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Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. ...
Photocopy of drawing. VEHICLE ASSEMBLY BUILDING MODIFICATIONS. NASA John F. Kennedy Space Center, Florida. File Number 79K05424, Seelye Stevenson Value & Knecht, March 1975. HIGH BAY 3, EXTENSIBLE WORK PLATFORM B, 2ND FLOOR PLAN, ARCHITECTURAL. Sheet 29 of 207 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL
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Environmental Monitoring for Situation Assessment using Mobile and Fixed Sensors
NASA Technical Reports Server (NTRS)
Fikes, Richard
2004-01-01
This project was co-led by Dr. Sheila McIlraith and Prof. Richard Fikes. Substantial research results and published papers describing those results were produced in multiple technology areas, including the following: 1) Monitoring a Complex Physical System using a Hybrid Dynamic Bayes Net; 2) A Formal Theory of Testing for Dynamical Systems; 3) Diagnosing Hybrid Systems Using a Bayesian Model Selection Approach.
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Prospects for natural world heritage sites in the Northwest Pacific Region
Jim Thorsell
2007-01-01
Alaska, northern British Columbia (BC), and the western portion of the Yukon Territory have extensive areas of wildlands that are matched by protected area systems covering some 20 percent of the land area of the region. One of the most outstanding of these is the Kluane/Wrangell-St. Elias/Glacier Bay/Tatshenshini-Alsek Park complex that is shared by all three...
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2018-05-01
The 2017 class of astronaut candidates tour Boeing's Commercial Crew and Cargo Facility at NASA's Kennedy Space Center in Florida on May 1. They are at the center for a familiarization tour of facilities, including the Neil Armstrong Operations and Checkout Building high bay; the Launch Control Center, Launch Complex 39B, and the Vehicle Assembly Building. They also toured United Launch Alliance's Space Launch Complex 41 at Cape Canaveral Air Force Station, and SpaceX's Launch Complex 39A at Kennedy. The candidates will spend about two years getting to know the space station systems and learning how to spacewalk, speak Russian, control the International Space Station's robotic arm and fly T-38s, before they're eligible to be assigned to a mission.
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2018-05-01
The 2017 class of astronaut candidates arrive at Boeing's Commercial Crew and Cargo Facility at NASA's Kennedy Space Center in Florida on May 1. They are at the center for a familiarization tour of facilities, including the Neil Armstrong Operations and Checkout Building high bay; the Launch Control Center, Launch Complex 39B, and the Vehicle Assembly Building. They also toured United Launch Alliance's Space Launch Complex 41 at Cape Canaveral Air Force Station, and SpaceX's Launch Complex 39A at Kennedy. The candidates will spend about two years getting to know the space station systems and learning how to spacewalk, speak Russian, control the International Space Station's robotic arm and fly T-38s, before they're eligible to be assigned to a mission.
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ETR AND MTR COMPLEXES IN CONTEXT. CAMERA FACING NORTHERLY. FROM ...
ETR AND MTR COMPLEXES IN CONTEXT. CAMERA FACING NORTHERLY. FROM BOTTOM TO TOP: ETR COOLING TOWER, ELECTRICAL BUILDING AND LOW-BAY SECTION OF ETR BUILDING, HEAT EXCHANGER BUILDING (WITH U SHAPED YARD), COMPRESSOR BUILDING. MTR REACTOR SERVICES BUILDING IS ATTACHED TO SOUTH WALL OF MTR. WING A IS ATTACHED TO BALCONY FLOOR OF MTR. NEAR UPPER RIGHT CORNER OF VIEW IS MTR PROCESS WATER BUILDING. WING B IS AT FAR WEST END OF COMPLEX. NEAR MAIN GATE IS GAMMA FACILITY, WITH "COLD" BUILDINGS BEYOND: RAW WATER STORAGE TANKS, STEAM PLANT, MTR COOLING TOWER PUMP HOUSE AND COOLING TOWER. INL NEGATIVE NO. 56-4101. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID
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NASA Astrophysics Data System (ADS)
Irby, I.; Friedrichs, M. A. M.
2017-12-01
Human impacts on the Chesapeake Bay through increased nutrient run-off as a result of land-use change, urbanization, and industrialization, have resulted in a degradation of water quality over the last half-century. These direct impacts, compounded with human-induced climate changes such as warming, rising sea level, and changes in precipitation, have elevated the conversation surrounding the future of the Bay's water quality. As a result, in 2010, a Total Maximum Daily Load (TMDL) was established for the Chesapeake Bay that limited nutrient and sediment input in an effort to increase dissolved oxygen. This research utilizes a multiple model approach to evaluate confidence in the estuarine water quality modeling portion of the TMDL. One of the models is then used to assess the potential impact climate change may have on the success of currently mandated nutrient reduction levels in 2050. Results demonstrate that although the models examined differ structurally and in biogeochemical complexity, they project a similar attainment of regulatory water quality standards after nutrient reduction, while also establishing that meeting water quality standards is relatively independent of hydrologic conditions. By developing a Confidence Index, this research identifies the locations and causes of greatest uncertainty in modeled projections of water quality. Although there are specific locations and times where the models disagree, this research lends an increased degree of confidence in the appropriateness of the TMDL levels and in the general impact nutrient reductions will have on Chesapeake Bay water quality under current environmental conditions. However, when examining the potential impacts of climate change, this research shows that the combined impacts of increasing temperature, sea level, and river flow negatively affect dissolved oxygen throughout the Chesapeake Bay and impact progress towards meeting the water quality standards associated with the TMDL with increased temperature as the primary culprit. These results, having been continually shared with the regulatory TMDL modelers, will aid in the decision making for the 2017 TMDL Mid-Point Assessment.
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Liu, Jiannong; Li, Suying; Gilbertson, David T; Monda, Keri L; Bradbury, Brian D; Collins, Allan J
2014-10-01
Because transfusion avoidance has been the cornerstone of anemia treatment for patients with kidney disease, direct measurement of red blood cell transfusion use to assess dialysis facility anemia management performance is reasonable. We aimed to explore methods for estimating facility-level standardized transfusion ratios (STfRs) to assess provider anemia treatment practices. Retrospective cohort study. Point prevalent US hemodialysis patients on January 1, 2009, with Medicare as primary payer and dialysis duration of 90 days or longer were included (n = 223,901). All dialysis facilities with eligible patients were included (n = 5,345). Dialysis facility assignment. Receiving a red blood cell transfusion in the inpatient or outpatient setting. We evaluated 3 approaches for estimating STfR: ratio of observed to expected numbers of transfusions (STfR(obs)), a Bayesian approach (STfR(Bayes)), and a modified version of the Bayesian approach (STfR(modBayes)). The overall national transfusion rate in 2009 was 23.2 per 100 patient-years. Our model for predicting the expected number of transfusions performed well. For large facilities, all 3 STfRs worked well. However, for small facilities, while the STfR(modBayes) worked well, STfR(obs) values demonstrated instability and the STfR(Bayes) may produce more bias. Administration of transfusions to dialysis patients reflects medical practice both within and outside the dialysis unit. Some transfusions may be deemed unavoidable and transfusion practices are subject to considerable regional variation. Development of an STfR metric is feasible and reasonable for assessing anemia treatment at dialysis facilities. The STfR(obs) is simple to calculate and works well for larger dialysis facilities. The STfR(modBayes) is more analytically complex, but facilitates comparisons across all dialysis facilities, including small facilities. Copyright © 2014 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.
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NASA Astrophysics Data System (ADS)
Patra, Anindita; Bhaskaran, Prasad K.
2017-08-01
The head Bay region bordering the northern Bay of Bengal is a densely populated area with a complex geomorphologic setting, and highly vulnerable to extreme water levels along with other factors like sea level rise and impact of tropical cyclones. The influence of climate change on wind-wave regime from this region of Bay of Bengal is not known well and that requires special attention, and there is a need to perform its long-term assessment for societal benefits. This study provides a comprehensive analysis on the temporal variability in domain averaged wind speed, significant wave height (SWH) utilizing satellite altimeter data (1992-2012) and mean wave period using ECMWF reanalysis products ERA-Interim (1992-2012) and ERA-20C (1992-2010) over this region. The SWH derived from WAVEWATCH III (WW3) model along with the ERA-Interim reanalysis supplements the observed variability in satellite altimeter observations. Further, the study performs an extensive error estimation of SWH and mean wave period with ESSO-NIOT wave atlas that shows a high degree of under-estimation in the wave atlas mean wave period. Annual mean and wind speed maxima from altimeter show an increasing trend, and to a lesser extent in the SWH. Interestingly, the estimated trend is higher for maxima compared to the mean conditions. Analysis of decadal variability exhibits an increased frequency of higher waves in the present decade compared to the past. Linear trend analysis show significant upswing in spatially averaged ERA-20C mean wave period, whereas the noticed variations are marginal in the ERA-Interim data. A separate trend analysis for the wind-seas, swell wave heights and period from ERA-20C decipher the fact that distant swells governs the local wind-wave climatology over the head Bay region, and over time the swell activity have increased in this region.
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NASA Astrophysics Data System (ADS)
Zheng, L.; Weisberg, R. H.
2016-02-01
A 3D, numerical circulation model, with high resolution (20 m) at important mass conveyances (inlets and rivers etc.), is developed to estimate the bulk residence time and diagnose the salt balances and salt fluxes for Tampa Bay estuary. These analyses are justified via quantitative comparisons between the simulation and observations of sea level, velocity and salinity. The non-tidal circulation is the primary agent for the flushing of Tampa Bay. Tides alone have a minor effect. Exceptions pertain to within a tidal excursion from the bay mouth and regions with multiple inlets where different tide phases aid in flushing. The fully 3D salt flux divergences (SFD) and fluxes vary spatially throughout the estuary. On experimental duration (three month) average, the total advective SFD is balanced primarily by the vertical diffusive SFD, except near the bottom of the channel where the horizontal diffusive SFD is also important. Instantaneously, the local rate of salinity change is controlled primarily by the advective SFD, with a secondary contribution by the vertical diffusive SFD everywhere and the horizontal diffusive SFD near the channel bottom. After decomposing the advective salt fluxes and their divergences into mean quantity and tidal pumping, the horizontal and vertical advective SFDs by the mean quantities are large and counterbalance, with their sum being a small but significant residual. The horizontal and vertical advective SFDs by tidal pumping are relatively small (when compared with the mean quantities) and counterbalance; but, when summed, their residual is comparable in magnitude to that by the mean quantities. So whereas the salt fluxes by tidal pumping are secondary importance to the salt fluxes by the mean quantities, their total flux divergences are of comparable importance. The salt flux 3D components vary along the Tampa Bay axis, and these findings may be typical of coastal plain estuaries given their geometrical complexities.
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NASA Astrophysics Data System (ADS)
Orson, Richard A.; Howes, Brian L.
1992-11-01
Stochastic events relating to beach formation and inlet dynamics have been the major factors influencing the development of the Waquoit Bay tidal marshes. This results from the physical structure of the Waquoit Bay system where tidal exchange is limited to one or two small inlets and is in contrast to marsh development in nearby Barnstable Marsh where direct unrestricted exchange with Cape Cod Bay has smoothed the effects of stochastic events on vegetation development. We contend that vegetation development in salt marshes where connections to adjacent waters are restricted will be dominated by abiotic factors (e.g. storms, sedimentation rates, etc.) while those marshes directly linked to open bodies of water and where alterations to hydrodynamic factors are gradual, autecological processes (e.g. interspecific competition) will dominate long-term plant community development. The results from the five marsh systems within the Waquoit Bay complex suggest that once a vegetation change occurs the new community tended to persist for long periods of time (100's-1000's years). Stability of the 'new' community appeared to depend upon the stability of the physical structure of the system and/or time between perturbations necessary to allow the slower autecological processes to have a discernable effect. In order for the plant community to persist as long as observed, the vegetation must also be exerting an influence on the processes of development. Increased production of roots and rhizomes and growth characteristics (density of culms) are some of the factors which help to maintain long-term species dominance. It is clear from this investigation that the structure of the plant community at any one point in time is dependent upon numerous factors including historical developmental influences. To properly assess changes to the present plant community or determine recent rates of accretion, historic developmental trends must be considered. The factors that have influenced the development of marsh in the past will be important in understanding and formulating predictive models in the future.
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Mercury dynamics in a coastal aquifer: Maunalua Bay, O´ahu, Hawai´i
NASA Astrophysics Data System (ADS)
Ganguli, Priya M.; Swarzenski, Peter W.; Dulaiova, Henrieta; Glenn, Craig R.; Flegal, A. Russell
2014-03-01
We evaluated the influence of groundwater-seawater interaction on mercury dynamics in Maunalua Bay, a coral reef ecosystem located on the south shore of O´ahu, Hawai´i, by combining geochemical data with submarine groundwater discharge (SGD) rates. During a rising tide, unfiltered total mercury (U-HgT) concentrations in seawater increased from ˜6 to 20 pM at Black Point (west Bay) and from ˜2.5 to 8 pM at Niu (central Bay). We attribute this change to an increase in suspended particulate matter at high tide. Approximately 90% of mercury in groundwater at Niu was in the filtered (<0.45 μm) fraction, with a concentration of ˜4 pM. Groundwater discharge during a period of amplified SGD at Niu appeared to contribute to an increase in total mercury concentrations in filtered seawater (F-HgT; 1.2 to 2.4 pM) and in unfiltered seawater (U-HgT; 2.5 to 3.2 pM). The larger magnitude of change in F-HgT relative to U-HgT suggests mercury complexation and/or solubility dynamics in seawater were altered by the addition of groundwater. We used site specific 222Rn derived SGD flux estimates and groundwater F-HgT concentrations to calculate mercury loadings at Black Point (˜3 nmol m-2 d-1) and at Niu (˜1 nmol m-2 d-1). We calculated a weighted average Maunalua Bay groundwater mercury flux of 0.68 ± 0.67 mol yr-1 by combining the proportional flux of F-HgT from three distinct SGD zones, and place these results into a broader context by comparing and contrasting flux estimates from locations around the world. Results from existing SGD studies should be evaluated to develop future sampling strategies that address more targeted questions about mercury biogeochemical cycling at the groundwater-seawater interface.
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NASA Astrophysics Data System (ADS)
Skilling, I. P.; Bluth, J.; Simoneau, E.
2011-12-01
The Koko fissure craters are aligned and nested basanitic tuff cones and rings at the SE corner of O'ahu, Hawai'i. There are no published studies of their stratigraphy, emplacement mechanisms or depositional paleoenvironments. This study focuses on a tuff cone complex (Koko Crater) and a younger adjacent nested tuff ring (Hanauma Bay). A detailed stratigraphy with logged sections for both Koko Crater and the Hanauma Bay craters are presented and discussed. Koko Crater is dominated by wet fallout deposits on steep proximal slopes, commonly resedimented by hot (vesiculated) and cold (unvesiculated) debris flows, slumps and slides, but with an increasing percentage of wet (low temperature) low concentration PDC deposits preserved in the shallowly-dipping flanking apron deposits, and in the uppermost proximal deposits. At least two earlier cone or ring rims are preserved along its southern margin. The deposits of Hanauma Bay overlie the Koko deposits and are dominated by a mix of wet low concentration PDC, wet fallout and synchronous PDC, and fallout deposits in proximal settings, and by low concentration, probably drier, PDC deposits in more distal settings. The Hanauma Bay rings were emplaced before the Koko Crater tephra was consolidated, as steep-sided rills incised into Koko tephra are locally filled with tephra of mixed Koko and Hanauma sources. The onset of Hanauma Bay eruptions is marked by a horizon that is very rich in rounded coral sand clasts. Discontinuous horizons and lenses of coral block fallout are also very common in the Hanauma tephra. Coral sand is absent and coral blocks are much rarer in the Koko tephra. These observations, and probably also the dominance of wet fallout at Koko, imply that Koko was erupted in deeper water than the nearshore coral beach environment of the Hanauma rings. A faster rate of water recharge into the conduit in deeper open water is probably the most important factor in the generation of a cone rather than a ring at this locality.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
2013-10-01
Under this project, Newport Partners (as part of the BA-PIRC research team) evaluated the installation, measured performance, and cost-effectiveness of efficiency upgrade measures for a tenant-in-place DER at the Bay Ridge multifamily (MF) development in Annapolis, Maryland. The design and construction phase of the Bay Ridge project was completed in August 2012. This report summarizes system commissioning, short-term test results, utility bill data analysis, and analysis of real-time data collected over a one-year period after the retrofit was complete. The Bay Ridge project is comprised of a "base scope" retrofit which was estimated to achieve a 30%+ savings (relative tomore » pre-retrofit) on 186 apartments, and a "DER scope" which was estimated to achieve 50% savings (relative to pre-retrofit) on a 12-unit building. The base scope was applied to the entire apartment complex, except for one 12-unit building which underwent the DER scope. A wide range of efficiency measures was applied to pursue this savings target for the DER building, including improvements/replacements of mechanical equipment and distribution systems, appliances, lighting and lighting controls, the building envelope, hot water conservation measures, and resident education. The results of this research build upon the current body of knowledge of multifamily retrofits. Towards this end, the research team has collected and generated data on the selection of measures, their estimated performance, their measured performance, and risk factors and their impact on potential measures.« less
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NASA Astrophysics Data System (ADS)
MacVean, L. J.; Thompson, S. E.; Huttom, P. H.; Sivapalan, M.
2016-02-01
California's Sacramento-San Joaquin Delta sits at the intersection of vast agricultural and population centers, and supplies fresh water for the diverse and often competing needs of ecosystems, farmers, and millions of Californians. Managing and allocating this resource is a complex feat of economics, politics, and engineering, made increasingly contentious by the ongoing drought. The objective of this research is to augment the scientific foundation of management decisions by addressing the question of how flows into the Delta have evolved in response to human intervention since 1850. In particular, quantifying the dynamic components of water usage through vegetative uptake and evapotranspiration, groundwater recharge, flood conveyance, and water exports at incremental levels of development is a key ambition. This approach emphasizes the built environment, which is subject to the local regulatory framework, rather than climate change, which is generally considered immovable without united global effort. This work encompasses the creation of a hydrologic model representing the watersheds of the San Francisco Bay-Delta system, and quantifies the impacts of changes in land use and the gradual construction of levees, reservoirs, and diversion infrastructure. The model is run using the same climatological forcing at each level of development, thus elucidating the effects of local anthropogenic activity on the Delta and the inflows to the San Francisco Bay estuary. Our results provide a timeline of change, giving decision-makers a scientifically established baseline to aid in the sustainable management of the Bay-Delta system.
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NASA Astrophysics Data System (ADS)
Kitaba, I.; Nakagawa, T.; McClymont, E.; Dettman, D. L.; Yamada, K.; Takemura, K.; Hyodo, M.
2014-12-01
Many of the difficulties in the pollen fossil-based paleoclimate reconstruction in coastal regions derive from the complex sedimentary processes of the near-shore environment. In order to examine this problem, we carried out pollen analysis of surface sediments collected from 35 sites in Osaka Bay, Japan. Using the biomisation method, the surrounding vegetation was accurately reconstructed at all sites. Applying the modern analogue technique to the same data, however, led to reconstructed temperatures that were lower by ca. 5 deg. C and precipitation amounts higher by ca. 5000 mm than the current sea level climate of the region. The range of reconstructed values was larger than the reconstruction error associated with the method. The principal component analysis shows that the surface pollen variation in Osaka Bay reflects sedimentary processes. This significant error associated with the quantitative climatic reconstruction using pollen data is attributed to the fact that the pollen assemblage is not determined solely by climate but reflects non-climatic influences. The accuracy and precision of climatic reconstruction can be improved significantly by expanding counts of minor taxa. Given this result, we re-examined the reconstructed climate using Osaka Bay palynological record reported in Kitaba et al. (2013). This new method did not significantly alter the overall variation in the reconstructed climate, and thus we conclude that the reconstruction was generally reliable. However, some intervals were strongly affected by depositional environmental change. In these, a climate signal can be extracted by excluding the patterns that arise from coastal sedimentation.
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NASA Astrophysics Data System (ADS)
O'Donncha, Fearghal; Hartnett, Michael; Nash, Stephen; Ren, Lei; Ragnoli, Emanuele
2015-02-01
In this study, High Frequency Radar (HFR), observations in conjunction with numerical model simulations investigate surface flow dynamics in a tidally-active, wind-driven bay; Galway Bay situated on the West coast of Ireland. Comparisons against ADCP sensor data permit an independent assessment of HFR and model performance, respectively. Results show root-mean-square (rms) differences in the range 10 - 12cm/s while model rms equalled 12 - 14cm/s. Subsequent analysis focus on a detailed comparison of HFR and model output. Harmonic analysis decompose both sets of surface currents based on distinct flow process, enabling a correlation analysis between the resultant output and dominant forcing parameters. Comparisons of barotropic model simulations and HFR tidal signal demonstrate consistently high agreement, particularly of the dominant M2 tidal signal. Analysis of residual flows demonstrate considerably poorer agreement, with the model failing to replicate complex flows. A number of hypotheses explaining this discrepancy are discussed, namely: discrepancies between regional-scale, coastal-ocean models and globally-influenced bay-scale dynamics; model uncertainties arising from highly-variable wind-driven flows across alarge body of water forced by point measurements of wind vectors; and the high dependence of model simulations on empirical wind-stress coefficients. The research demonstrates that an advanced, widely-used hydro-environmental model does not accurately reproduce aspects of surface flow processes, particularly with regards wind forcing. Considering the significance of surface boundary conditions in both coastal and open ocean dynamics, the viability of using a systematic analysis of results to improve model predictions is discussed.
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NASA Astrophysics Data System (ADS)
Goebel, M.; Knight, R. J.; Pidlisecky, A.
2016-12-01
Coastal regions represent a complex dynamic interface where saltwater intrusion moves seawater landward and groundwater discharge moves freshwater seaward. These processes can have a dramatic impact on water quality, affecting both humans and coastal ecosystems. The ability to map the subsurface distribution of fresh and salt water is a critical step in predicting and managing water quality in coastal regions. This is commonly accomplished using wells, which are expensive and provide point information, which may fail to capture the spatial complexity in subsurface conditions. We present an alternate method for acquiring data, long-offset Electrical Resistivity Tomography (ERT), which is non-invasive, cost effective, and can address the problem of poor spatial sampling. This geophysical method can produce continuous profiles of subsurface electrical resistivity to a depth of 300 m, with spatial resolution on the order of tens of meters. Our research focuses on the Monterey Bay region, where sustained groundwater extraction over the past century has led to significant saltwater intrusion. ERT was acquired along 40 kilometers of the coast using the roll along method, allowing for continuous overlap in data acquisition. Electrodes were spaced every 22.2 m, with a total of 81 electrodes along the 1.8 km active cable length. The data show a complex distribution of fresh and salt water, influenced by geology, groundwater pumping, recharge, and land-use. While the inverted ERT resistivity profiles correspond well with existing data sets and geologic interpretations in the region, the spatial complexity revealed through the ERT data goes beyond what is known from traditional data sources alone. This leads us to conclude that this form of data can be extremely useful in informing and calibrating groundwater flow models, making targeted management decisions, and monitoring changes in subsurface salinities over time.
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Lionberger, Megan A.; Schoellhamer, David H.; Shellenbarger, Gregory; Orlando, James L.; Ganju, Neil K.
2007-01-01
This report documents the development and application of a box model to simulate water level, salinity, and temperature of the Alviso Salt Pond Complex in South San Francisco Bay. These ponds were purchased for restoration in 2003 and currently are managed by the U.S. Fish and Wildlife Service to maintain existing wildlife habitat and prevent a build up of salt during the development of a long-term restoration plan. The model was developed for the purpose of aiding pond managers during the current interim management period to achieve these goals. A previously developed box model of a salt pond, SPOOM, which calculates daily pond volume and salinity, was reconfigured to simulate multiple connected ponds and a temperature subroutine was added. The updated model simulates rainfall, evaporation, water flowing between the ponds and the adjacent tidal slough network, and water flowing from one pond to the next by gravity and pumps. Theoretical and measured relations between discharge and corresponding differences in water level are used to simulate most flows between ponds and between ponds and sloughs. The principle of conservation of mass is used to calculate daily pond volume and salinity. The model configuration includes management actions specified in the Interim Stewardship Plan for the ponds. The temperature subroutine calculates hourly net heat transfer to or from a pond resulting in a rise or drop in pond temperature and daily average, minimum, and maximum pond temperatures are recorded. Simulated temperature was compared with hourly measured data from pond 3 of the Napa?Sonoma Salt Pond Complex and monthly measured data from pond A14 of the Alviso Salt-Pond Complex. Comparison showed good agreement of measured and simulated pond temperature on the daily and monthly time scales.
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ALGE3D: A Three-Dimensional Transport Model
NASA Astrophysics Data System (ADS)
Maze, G. M.
2017-12-01
Of the top 10 most populated US cities from a 2015 US Census Bureau estimate, 7 of the cities are situated near the ocean, a bay, or on one of the Great Lakes. A contamination of the water ways in the United States could be devastating to the economy (through tourism and industries such as fishing), public health (from direct contact, or contaminated drinking water), and in some cases even infrastructure (water treatment plants). Current national response models employed by emergency response agencies have well developed models to simulate the effects of hazardous contaminants in riverine systems that are primarily driven by one-dimensional flows; however in more complex systems, such as tidal estuaries, bays, or lakes, a more complex model is needed. While many models exist, none are capable of quick deployment in emergency situations that could contain a variety of release situations including a mixture of both particulate and dissolved chemicals in a complex flow area. ALGE3D, developed at the Department of Energy's (DOE) Savannah River National Laboratory (SRNL), is a three-dimensional hydrodynamic code which solves the momentum, mass, and energy conservation equations to predict the movement and dissipation of thermal or dissolved chemical plumes discharged into cooling lakes, rivers, and estuaries. ALGE3D is capable of modeling very complex flows, including areas with tidal flows which include wetting and drying of land. Recent upgrades have increased the capabilities including the transport of particulate tracers, allowing for more complete modeling of the transport of pollutants. In addition the model is capable of coupling with a one-dimension riverine transport model or a two-dimension atmospheric deposition model in the event that a contamination event occurs upstream or upwind of the water body.
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Dong, Linsong; Wang, Zhiyong
2018-06-11
Genomic prediction is feasible for estimating genomic breeding values because of dense genome-wide markers and credible statistical methods, such as Genomic Best Linear Unbiased Prediction (GBLUP) and various Bayesian methods. Compared with GBLUP, Bayesian methods propose more flexible assumptions for the distributions of SNP effects. However, most Bayesian methods are performed based on Markov chain Monte Carlo (MCMC) algorithms, leading to computational efficiency challenges. Hence, some fast Bayesian approaches, such as fast BayesB (fBayesB), were proposed to speed up the calculation. This study proposed another fast Bayesian method termed fast BayesC (fBayesC). The prior distribution of fBayesC assumes that a SNP with probability γ has a non-zero effect which comes from a normal density with a common variance. The simulated data from QTLMAS XII workshop and actual data on large yellow croaker were used to compare the predictive results of fBayesB, fBayesC and (MCMC-based) BayesC. The results showed that when γ was set as a small value, such as 0.01 in the simulated data or 0.001 in the actual data, fBayesB and fBayesC yielded lower prediction accuracies (abilities) than BayesC. In the actual data, fBayesC could yield very similar predictive abilities as BayesC when γ ≥ 0.01. When γ = 0.01, fBayesB could also yield similar results as fBayesC and BayesC. However, fBayesB could not yield an explicit result when γ ≥ 0.1, but a similar situation was not observed for fBayesC. Moreover, the computational speed of fBayesC was significantly faster than that of BayesC, making fBayesC a promising method for genomic prediction.
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Aquatic sources and sinks for nitrous oxide
NASA Technical Reports Server (NTRS)
Elkins, J. W.; Wofsy, S. C.; Mcelroy, M. B.; Kaplan, W. A.; Kolb, C. E.
1978-01-01
Data are presented which suggest the complexity of the aquatic nitrogen cycle as it affects N2O. The data are from studies made in the central and south-east tropical regions of the Pacific Ocean and in Chesapeake Bay. The data indicate that oxidation of ammonium and amino nitrogen and nitrification form the principle source for marine N2O. It is estimated that the yearly global yield for oceanic N2O is less than about 10 to the 7th power tons. The consumption of atmospheric N2O by the open ocean has not been evidenced, although data from the south-east tropical Pacific and Chesapeake Bay show the consumption of dissolved N2O in low-oxygen conditions. Preliminary observations have also indicated the consumption of atmospheric N2O by aquatic systems such as freshwater pond and a tidal saltmarsh.
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2004-03-26
CAPE CANAVERAL, Fla. -- This aerial photo shows the expanse of the Launch Complex 39 Area, bordered on the east by the Atlantic Ocean and cloud-filled sky. At center right, towering above the surrounding sites, is the Vehicle Assembly Building. To the left, or north, is the Orbiter Processing Facility’s Bay 3. On the western side are OPF Bays 1 and 2. South, near the roadway, is the Operations Support Building. The two-lane crawlerway stretches from the VAB toward the coast, site of Launch Pad 39A, closest, and Launch Pad 39B, far left. Between the VAB and the ocean sprawl the Banana Creek and the Banana River. The turn basin, at right, allows delivery of external tanks that are offloaded close to and transported to the VAB. At the western end of the Turn Basin sits the press mound, home of the NASA KSC News Center. Photo credit: NASA
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Aerial photo shows Launch Complex 39 Area
NASA Technical Reports Server (NTRS)
2000-01-01
This aerial photo captures many of the facilities involved in Space Shuttle launches. At center is the Vehicle Assembly Building (VAB). The curved road on the near side is the newly restored crawlerway leading into the VAB high bay 2, where a mobile launcher platform/crawler-transporter currently sits. The road restoration and high bay 2 are part of KSC's Safe Haven project, enabling the storage of orbiters during severe weather. The road circles around the Orbiter Processing Facility 3 (OPF-3) at left center. OPF1 and OPF-2 are just below the curving road. The crawlerway also extends from the east side of the VAB out to the two launch pads, only one visible to the left of the VAB. In the distance is the Atlantic Ocean. To the right of the far crawlerway is the turn basin, into which ships tow the barge for offloading new external tanks from Louisiana.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Tymura, E.J.
1981-01-01
Solar Energy Heating Applications are On the Rise in and above the Northwestern City of Thunder Bay, on the northern shore of Lake Superior. Unique in their diversifications, the architectural commissions range from pure passive residential design thru hybrid systems; residential Greenhouse-Solarium active swimming pool and commercial hotel pool to inexpensive hybrid system for Canada's First Commercial Solar Lumber Drying Kiln; as well as combined earth sheltered with solar system design for a dormitory complex and shopping center. By May 1981, 7 buildings designed by Tymura Solardesigns in the Thunder Bay area will have been subjected to the Extreme Canadianmore » climate (10,500/sup 0/F degree days, yearly temperature maximums from -41/sup 0/F to 90/sup 0/F, and solar fractions vary from 50% to 75%, with economic payback periods ranging between 7 and 10 years.« less
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Coordinated Field Campaigns in Chesapeake Bay and Gulf of Mexico
NASA Technical Reports Server (NTRS)
Mannino, Antonio; Novak, Michael; Tzortziou, Maria A.
2015-01-01
NASA's GEOstationary Coastal and Air Pollution Events (GEO-CAPE) mission concept recommended by the U.S. National Research Council (2007) focuses on measurements of atmospheric trace gases and aerosols and aquatic coastal ecology and biogeochemistry from geostationary orbit (35,786 km altitude). Two GEO-CAPE-sponsored multi-investigator ship-based field campaigns were conducted to coincide with the NASA Earth Venture Suborbital project DISCOVER-AQ (Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality) field campaigns: (1) Chesapeake Bay in July 2011 and (2) northwestern Gulf of Mexico in September 2013. Goal: to evaluate whether GEO-CAPE coastal mission measurement and instrument requirements are optimized to address science objectives while minimizing ocean color satellite sensor complexity, size and cost - critical mission risk reduction activities. NASA continues to support science studies related to the analysis of data collected as part of these coordinated field campaigns and smaller efforts.
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New biosorbent in removing some metals from industrial wastewater in El Mex Bay, Egypt
NASA Astrophysics Data System (ADS)
Abdallah, Maha Ahmed Mohamed; Mahmoud, Mohamed E.; Osman, Maher M.; Ahmed, Somaia B.
2017-07-01
Biosorption is an extensive technology applied for the removal of heavy metal ions and other pollutants from aqueous solutions. In the present study, the biosorption of cadmium, lead, chromium and mercury ions from polluted surface seawater in El-Max Bay was determined using hybrid active carbon sorbents. These sorbents were treated chemically by acid, base and redox reaction followed by surface loading of baker's yeast biomass for increasing their biosorption capacity and the highest metal uptake values. The surface function and morphology of the hybrid immobilized sorbents were studied by Fourier Transform Infrared analysis and scanning electron microscope imaging. Metal removal values proved that the vital role of baker's yeast as a significant high removable due to functional groups at baker's yeast cell wall surface that have the ability to forming various coordination complexes with metal ions. A noticeable increase in the removal of all studied metals was observed and reached to 100 %.
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Mixed sediment beach processes: Kachemak Bay, Alaska
Ruggiero, P.; Adams, P.N.; Warrick, J.A.
2007-01-01
Mixed sediment beaches are morphologically distinct from and more complex than either sand or gravel only beaches. Three digital imaging techniques are employed to quantify surficial grain size and bedload sediment transport rates along the mixed sediment beaches of Kachemak Bay, Alaska. Applying digital imaging procedures originally developed for quickly and efficiently quantifying grain sizes of sand to coarse sediment classes gives promising results. Hundreds of grain size estimates lead to a quantitative characterization of the region's sediment at a significant reduction in cost and time as compared to traditional techniques. Both the sand and coarse fractions on this megatidal beach mobilize into self-organized bedforms that migrate alongshore with a seasonally reflecting the temporal pattern of the alongshore component of wave power. In contrast, the gravel bedforms also migrate in the cross-shore without significant seasonally suggesting that swash asymmetry is sufficient to mobilize the gravel even during low energy summer conditions. ?? 2007 ASCE.
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Interpretation FTIR spectrum of seawater and sediment in the Ambon Bay (TAD)
NASA Astrophysics Data System (ADS)
Patty, Diana Julaidy; Loupatty, Grace; Sopalauw, Fitria
2017-01-01
Research has done to interpretated FTIR spectrum of seawaters and sediment of the Ambon Bay (TAD). Analysis of samples of sediment and seawater using FTIR spectroscopy. The results showed the sand sediment samples identified Stretch bond OH group (3600-3500 cm-1), N-H Stretch (3400-3300 cm-1), C≡N (2250 cm-1), and NH bending (1640 to 1550 cm-1). And for seawater samples identified bonding group that is N-H Stretch (3400-3350 cm-1), N-H bending (1640 to 1550 cm-1) and C=O (1670-1640 cm-1). The existence of functional groups, carbonyl (C=O), alcohol (OH), carboxyl (COOH) can cause the complexation of metal cations. And the results showed analysis group N-O bond-containing compounds Nitro indicate heavy metal content of Lead (Pb) and group N-H bond-containing compound Amina indicate heavy metal content of Cadmium (Cd).
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Details: Elevation of Plate Typical Bay, SectionThrough Plate Typical Bay, ...
Details: Elevation of Plate Typical Bay, Section-Through Plate Typical Bay, Section-Through Plate Center Bay, Elevation of Plate Center Bay - Contoocook Covered Bridge, Spanning Contoocook River, Hopkinton, Merrimack County, NH
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NASA Astrophysics Data System (ADS)
Yang, Ye; Chui, Ting Fong May
2017-07-01
Many coastal areas worldwide have been reclaimed to meet the increasing land demand. Understanding the effects of land reclamation on the hydrodynamics and transport processes of a semi-enclosed bay is therefore of significance. From a case study of Deep Bay (DB) in China and referring to idealized bay models, the effects of two types of land reclamation, one that narrows the bay mouth and another that reduces the water area inside the bay, were examined in this study. Simulation results of idealized models show that the current velocity at the bay mouth and the incoming tidal energy flux are negatively correlated with the width of bay mouth, as the tidal prism remains almost constant when the bay mouth width reduces. The bay mouth width reduction would also increase the tidal energy dissipation inside of the bay due to friction increase. In DB, a 30% reduction in the mouth width increased the bay mouth current velocity by up to 5% and the total incoming energy flux by 18%. The narrowed bay mouth also substantially changed the bay's vertical structure of salinity, increasing the stratification strength by 1.7×10-4 s-2. For reductions in the water surface area in the head of the bay, results from idealized bay simulations show that the current velocity throughout the bay, the incoming tidal energy flux, and salinity at the inner bay all decrease with water area reduction. Reclaiming 14% of area in DB, the current velocity reduced by 9% at the bay mouth, but increased in the middle and inner parts. The incoming tidal energy flux also increased as the coastline became more streamlined after reclamation, and the salinity at inner bay decreased. Both reclamation types have substantially altered the water and salt transport processes and increased the water exchange ability of the bay with the adjacent sea.
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Ground-water conditions in the Green Bay area, Wisconsin, 1950-60
Knowles, Doyle B.
1964-01-01
The Green Bay area, which includes parts of Brown, Outagamie, and Shawano Counties, has an area of about 525 square miles in eastern Wisconsin at the south end of Green Bay. In 1960, it had a population estimated at 124,000; Green Bay, the largest city in the area, had a population of 62,888. The Green Bay area is underlain by a basement complex of crystalline rocks of Precambrian age. Sedimentary rocks of Cambrian, Ordovician, and Silurian ages overlie the crystalline rocks. These rocks are divided, in ascending order, as follows: The Dresbach Group, Franconia Sandstone, and Trempealeau Formation of Cambrian age; the Prairie du Chien Group, St. Peter Sandstone, Platteville Formation, and Maquoketa Shale of Ordovician age; and the Niagara Dolomite of Silurian age. The Maquoketa Shale and Niagara Dolomite are present only in the eastern part of the area. Unconsolidated deposits, largely of Pleistocene age and glacial origin, overlie the older rocks in most of the area. The rocks of the Dresbach Group, Franconia Sandstone, Trempealeau Formation, Prairie du Chien Group, and St. Peter Sandstone are connected hydraulically and can be considered to form one aquifer, called the sandstone aquifer. The sandstone aquifer is the principal source of ground-water supply in the Green Bay area and is one of the most productive water-bearing units in Wisconsin. All the public water supplies in the area, except the supply for the city of Green Bay, and many of the industrial water supplies are obtained from wells tapping the sandstone aquifer. Rates of discharge of individual wells range from about 200 to 1,000 gallous per minute. The city of Green Bay also obtained its water supply from wells tapping the sandstone aquifer until August 1957, when it began using Lake Michigan as a source of water supply. Several industries also use large quantities of surface water. The Niagara Dolomite, although largely undeveloped, is potentially an important aquifer, in the eastern part of the area. Small amounts of water are obtained from dolomite of the Platteville Formation and from sand and gravel deposits of Pleistocene age. Recharge to the sandstone aquifer in the Green Bay area is derived chiefly from precipitation that infiltrates at or near the outcrop area of the aquifer in northwestern Brown County, eastern Outagamie and Shawano Counties, and southern Oconto County. The amount of recharge is estimated to be at least 30 mgd (million gallons per day). Withdrawals of water from wells tapping the sandstone aquifer in the area began when the first well was drilled in 1886. The withdrawals gradually increased to an average of about 6 mgd in 1940, about 10 mgd in 1950, and about 13 mgd in January-July of 1957, after which time the city of Green Bay discontinued pumping from wells. From August 1957 through 1960, average annual withdrawals of water remained relatively constant at about 5 mgd. Water levels in wells tapping the sandstone aquifer persistently declined until August 1957 as a result of the gradually increasing withdrawals of water. In the area of concentrated ground-water withdrawals in downtown Green Bay, the piezometric surface, which had been about 100 feet above land surface in 1886, was about 340 feet below land surface in 1957. The cessation of pumping by the city of Green Bay in August 1957 resulted in a decrease in withdrawals of ground water from about 13.1 mgd in the first half of 1957 to about 5.3 mgd in the last half and a rapid recovery in water levels. ]n the area of concentrated withdrawals, the piezometric surface had recovered about 300 feet by September 1960. Rises in water levels were recorded throughout the Green Bay area, with the amount of the rise depending on the distance from the Green Bay city wells. In September 1960, water levels appeared to be affected more by local variations in the rates of pumping than by the recovery resulting from 1957 reduction in pumping. Much additional ground water could
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Soriano, Sylvain; Villa, Paola; Delagnes, Anne; Degano, Ilaria; Pollarolo, Luca; Lucejko, Jeannette J; Henshilwood, Christopher; Wadley, Lyn
2015-01-01
The classification of archaeological assemblages in the Middle Stone Age of South Africa in terms of diversity and temporal continuity has significant implications with respect to recent cultural evolutionary models which propose either gradual accumulation or discontinuous, episodic processes for the emergence and diffusion of cultural traits. We present the results of a systematic technological and typological analysis of the Still Bay assemblages from Sibudu and Blombos. A similar approach is used in the analysis of the Howiesons Poort (HP) assemblages from Sibudu seen in comparison with broadly contemporaneous assemblages from Rose Cottage and Klasies River Cave 1A. Using our own and published data from other sites we report on the diversity between stone artifact assemblages and discuss to what extent they can be grouped into homogeneous lithic sets. The gradual evolution of debitage techniques within the Howiesons Poort sequence with a progressive abandonment of the HP technological style argues against the saltational model for its disappearance while the technological differences between the Sibudu and Blombos Still Bay artifacts considerably weaken an interpretation of similarities between the assemblages and their grouping into the same cultural unit. Limited sampling of a fragmented record may explain why simple models of cultural evolution do not seem to apply to a complex reality.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Corvinus, D.A.
1982-01-01
The Okefenokee Swamp, over 400,000 acres, is a swamp-marsh complex dominated by Taxodium-swamp vegetaion on its west side and Nymphaea-marsh vegetation onits east side. The Albemarle-Pamlico Peninsular Swamps primarily support a pocosin-bay vegetation. The Taxodium-dominated peats of the Okefenokee are more similar botanically to the Albemarle-Pamlico bay peats than are the Okefenokee Nymphaea-dominated peats. Some petrographic characteristics are common to all three peat types. The majority of cell walls in the peat exhibit colors (yellow to orange to red) which they did not display in their living state. This is believed to be from impregnation by the various cell fillingsmore » present in the peats. Unoxidized fragmented (granular) material in all three peat types usually occurs in larger amounts than oxidized (darkened) material. In Taxodium-dominated and bay peats the fragmented matrix is also usually more prevalent than the preserved material (intact cell walls and cell fillings). On the other hand, preserved material is most common in Nymphaea-dominated peats. It is believed that the majority of fragmented material is derived from the surface litter and that swamp vegetation contributes more surface litter than does marsh vegetation.« less
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The Still Bay and Howiesons Poort at Sibudu and Blombos: Understanding Middle Stone Age Technologies
Soriano, Sylvain; Villa, Paola; Delagnes, Anne; Degano, Ilaria; Pollarolo, Luca; Lucejko, Jeannette J.; Henshilwood, Christopher; Wadley, Lyn
2015-01-01
The classification of archaeological assemblages in the Middle Stone Age of South Africa in terms of diversity and temporal continuity has significant implications with respect to recent cultural evolutionary models which propose either gradual accumulation or discontinuous, episodic processes for the emergence and diffusion of cultural traits. We present the results of a systematic technological and typological analysis of the Still Bay assemblages from Sibudu and Blombos. A similar approach is used in the analysis of the Howiesons Poort (HP) assemblages from Sibudu seen in comparison with broadly contemporaneous assemblages from Rose Cottage and Klasies River Cave 1A. Using our own and published data from other sites we report on the diversity between stone artifact assemblages and discuss to what extent they can be grouped into homogeneous lithic sets. The gradual evolution of debitage techniques within the Howiesons Poort sequence with a progressive abandonment of the HP technological style argues against the saltational model for its disappearance while the technological differences between the Sibudu and Blombos Still Bay artifacts considerably weaken an interpretation of similarities between the assemblages and their grouping into the same cultural unit. Limited sampling of a fragmented record may explain why simple models of cultural evolution do not seem to apply to a complex reality. PMID:26161665
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Colbeck, Gabriel J.; Duchesne, Pierre; Postma, Lianne D.; Lesage, Véronique; Hammill, Mike O.; Turgeon, Julie
2013-01-01
Social structure involving long-term associations with relatives should facilitate the learning of complex behaviours such as long-distance migration. In and around Hudson Bay (Canada), three stocks of beluga whales form a panmictic unit, but have different migratory behaviours associated with different summering areas. We analysed genetic variation at 13 microsatellite loci among 1524 belugas, to test hypotheses about social structure in belugas. We found significant proportions of mother–offspring pairs throughout the migratory cycle, but average relatedness extended beyond close kinship only during migration. Average relatedness was significantly above random expectations for pairs caught at the same site but on different days or months of a year, suggesting that belugas maintain associations with a network of relatives during migration. Pairs involving a female (female–female or male–female) were on average more related than pairs of males, and males seemed to disperse from their matrilineal group to associate with other mature males. Altogether, our results indicate that relatives other than strictly parents, and especially females, play a role in maintaining a social structure that could facilitate the learning of migration routes. Cultural conservatism may limit contributions from nearby summer stocks to endangered stocks such as the Eastern Hudson Bay beluga. PMID:23222451
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Evaluation and Validation of Case 2 Algorithms in Chesapeake Bay
NASA Technical Reports Server (NTRS)
Harding, Lawrence W., Jr.; Magnuson, Adrea
2004-01-01
The high temporal and spatial resolution of satellite ocean color observations will prove invaluable for monitoring the health of coastal ecosystems where physical and biological variability demands sampling scales beyond that possible by ship. However, ocean color remote sensing of Case 2 waters is a challenging undertaking due to the optical complexity of the water. The focus of this SIMBIOS support has been to provide in situ optical measurements form Chesapeake Bay (CB) and adjacent mid-Atlantic bight (MAB) waters for use in algorithm development and validation efforts to improve the satellite retrieval of chlorophyll (chl a) in Case 2 waters. CB provides a valuable site for validation of data from ocean color sensors for a number of reasons. First, the physical dimensions of the Bay (greater than 6,500 square kilometers) make retrievals from satellites with a spatial resolution of approximately 1 kilometer (i.e., SeaWiFS) or less (i.e., MODIS) reasonable for most of the ecosystem. Second, CB is highly influenced by freshwater flow from major rivers, making it a classic Case 2 water body with significant concentrations of chlorophyll, particulates and chromophoric dissolved organic matter (CDOM) that highly impact the shape of reflectance spectra. Finally, past and ongoing research efforts provided an expensive data set of optical observations that support the goal of this project.
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Bio-Optics of the Chesapeake Bay from Measurements and Radiative Transfer Calculations
NASA Technical Reports Server (NTRS)
Tzortziou, Maria; Herman, Jay R.; Gallegos, Charles L.; Neale, Patrick J.; Subramaniam, Ajit; Harding, Lawrence W., Jr.; Ahmad, Ziauddin
2005-01-01
We combined detailed bio-optical measurements and radiative transfer (RT) modeling to perform an optical closure experiment for optically complex and biologically productive Chesapeake Bay waters. We used this experiment to evaluate certain assumptions commonly used when modeling bio-optical processes, and to investigate the relative importance of several optical characteristics needed to accurately model and interpret remote sensing ocean-color observations in these Case 2 waters. Direct measurements were made of the magnitude, variability, and spectral characteristics of backscattering and absorption that are critical for accurate parameterizations in satellite bio-optical algorithms and underwater RT simulations. We found that the ratio of backscattering to total scattering in the mid-mesohaline Chesapeake Bay varied considerably depending on particulate loading, distance from land, and mixing processes, and had an average value of 0.0128 at 530 nm. Incorporating information on the magnitude, variability, and spectral characteristics of particulate backscattering into the RT model, rather than using a volume scattering function commonly assumed for turbid waters, was critical to obtaining agreement between RT calculations and measured radiometric quantities. In situ measurements of absorption coefficients need to be corrected for systematic overestimation due to scattering errors, and this correction commonly employs the assumption that absorption by particulate matter at near infrared wavelengths is zero.
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Colbeck, Gabriel J; Duchesne, Pierre; Postma, Lianne D; Lesage, Véronique; Hammill, Mike O; Turgeon, Julie
2013-02-07
Social structure involving long-term associations with relatives should facilitate the learning of complex behaviours such as long-distance migration. In and around Hudson Bay (Canada), three stocks of beluga whales form a panmictic unit, but have different migratory behaviours associated with different summering areas. We analysed genetic variation at 13 microsatellite loci among 1524 belugas, to test hypotheses about social structure in belugas. We found significant proportions of mother-offspring pairs throughout the migratory cycle, but average relatedness extended beyond close kinship only during migration. Average relatedness was significantly above random expectations for pairs caught at the same site but on different days or months of a year, suggesting that belugas maintain associations with a network of relatives during migration. Pairs involving a female (female-female or male-female) were on average more related than pairs of males, and males seemed to disperse from their matrilineal group to associate with other mature males. Altogether, our results indicate that relatives other than strictly parents, and especially females, play a role in maintaining a social structure that could facilitate the learning of migration routes. Cultural conservatism may limit contributions from nearby summer stocks to endangered stocks such as the Eastern Hudson Bay beluga.
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Smart, K.J.; Pavlis, T.L.; Sisson, V.B.; Roeske, S.M.; Snee, L.W.
1996-01-01
The Border Ranges fault system of southern Alaska, the fundamental break between the arc basement and the forearc accretionary complex, is the boundary between the Peninsular-Alexander-Wrangellia terrane and the Chugach terrane. The fault system separates crystalline rocks of the Alexander terrane from metamorphic rocks of the Chugach terrane in Glacier Bay National Park. Mylonitic rocks in the zone record abundant evidence for dextral strike-slip motion along north-northwest-striking subvertical surfaces. Geochronologic data together with regional correlations of Chugach terrane rocks involved in the deformation constrain this movement between latest Cretaceous and Early Eocene (???50 Ma). These findings are in agreement with studies to the northwest and southeast along the Border Ranges fault system which show dextral strike-slip motion occurring between 58 and 50 Ma. Correlations between Glacier Bay plutons and rocks of similar ages elsewhere along the Border Ranges fault system suggest that as much as 700 km of dextral motion may have been accommodated by this structure. These observations are consistent with oblique convergence of the Kula plate during early Cenozoic and forearc slivering above an ancient subduction zone following late Mesozoic accretion of the Peninsular-Alexander-Wrangellia terrane to North America.
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Wang, Hongqing; Chen, Qin; Hu, Kelin; Snedden, Gregg A.; Hartig, Ellen K.; Couvillion, Brady R.; Johnson, Cody L.; Orton, Philip M.
2017-03-29
The salt marshes of Jamaica Bay, managed by the New York City Department of Parks & Recreation and the Gateway National Recreation Area of the National Park Service, serve as a recreational outlet for New York City residents, mitigate flooding, and provide habitat for critical wildlife species. Hurricanes and extra-tropical storms have been recognized as one of the critical drivers of coastal wetland morphology due to their effects on hydrodynamics and sediment transport, deposition, and erosion processes. However, the magnitude and mechanisms of hurricane effects on sediment dynamics and associated coastal wetland morphology in the northeastern United States are poorly understood. In this study, the depth-averaged version of the Delft3D modeling suite, integrated with field measurements, was utilized to examine the effects of Hurricane Sandy and future potential hurricanes on salt marsh morphology in Jamaica Bay, New York City. Hurricane Sandy-induced wind, waves, storm surge, water circulation, sediment transport, deposition, and erosion were simulated by using the modeling system in which vegetation effects on flow resistance, surge reduction, wave attenuation, and sedimentation were also incorporated. Observed marsh elevation change and accretion from a rod surface elevation table and feldspar marker horizons and cesium-137- and lead-210-derived long-term accretion rates were used to calibrate and validate the wind-waves-surge-sediment transport-morphology coupled model.The model results (storm surge, waves, and marsh deposition and erosion) agreed well with field measurements. The validated modeling system was then used to detect salt marsh morphological change due to Hurricane Sandy across the entire Jamaica Bay over the short-term (for example, 4 days and 1 year) and long-term (for example, 5 and 10 years). Because Hurricanes Sandy (2012) and Irene (2011) were two large and destructive tropical cyclones which hit the northeast coast, the validated coupled model was run to predict the effects of Sandy-like and Irene-like hurricanes with different storm tracks and wind intensities on wetland morphology in Jamaica Bay. Model results indicate that, in Jamaica Bay salt marshes, the morphological changes (greater than 5 millimeters [mm] determined by the long-term marsh accretion rate) caused by Hurricane Sandy were complex and spatially heterogeneous. Most of the erosion (5–40 mm) and deposition (5–30 mm) were mainly characterized by fine sand for channels and bay bottoms and by mud for marsh areas. Hurricane Sandy-generated deposition and erosion were generated locally. The storm-induced net sediment input through Rockaway Inlet was only about 1 percent of the total amount of the sediment reworked by the hurricane. Salt marshes inside the western part of the bay showed erosion overall while marshes inside the eastern part showed deposition from Hurricane Sandy. Model results indicated that most of the marshes could recover from Hurricane Sandy-induced erosion after 1 year and demonstrated continued marsh accretion after the hurricane over the course of long simulation periods although the effect (accretion) was diminished. Local waves and currents generated by Hurricane Sandy appeared to play a critical role in sediment transport and associated wetland morphological change in Jamaica Bay. Hypothetical hurricanes, depending on their track and intensity, cause variable responses in spatial patterns of sediment deposition and erosion compared to simulations without the hurricane. In general, hurricanes passing west of the Jamaica Bay estuary appear to be more destructive to the salt marshes than those passing the east. Consequently, marshes inside the western part of the bay were likely to be more vulnerable to hurricanes than marshes inside the eastern part of the bay.
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77 FR 70891 - Safety Zone; Bay Bridge Construction, San Francisco Bay, San Francisco, CA
Federal Register 2010, 2011, 2012, 2013, 2014
2012-11-28
...-AA00 Safety Zone; Bay Bridge Construction, San Francisco Bay, San Francisco, CA AGENCY: Coast Guard... the navigable waters of the San Francisco Bay near Yerba Buena Island, CA in support of the Bay Bridge... construction of the Bay Bridge, the safety zone is necessary to provide for the safety of mariners transiting...
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Exterior view of ISS and Shuttle Atlantis
2011-07-14
ISS028-E-016368 (14 July 2011) --- This panoramic view, photographed from the International Space Station, looking past the docked space shuttle Atlantis' cargo bay and part of the station including a solar array panel toward Earth, was taken on July 14 as the joint complex passed over the southern hemisphere. Aurora Australis or the Southern Lights can be seen on Earth's horizon and a number of stars are visible also.
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1998-12-07
S88-E-5058 (12-08-98) --- Astronaut Jerry L. Ross takes a picture during a 7-hour, 21 minute spacewalk. Astronauts Ross and James H. Newman went on to mate 40 cables and connectors runing 76 feet from the Zarya control module to Unity, with the 35-ton complex towering over Endeavour's cargo bay. The photo was taken with an electronic still camera (ESC) at 00:35:05 GMT, Dec. 8.
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Noncoherent detection of periodic signals
NASA Technical Reports Server (NTRS)
Gagliardi, R. M.
1974-01-01
The optimal Bayes detector for a general periodic waveform having uniform delay and additive white Gaussian noise is examined. It is shown that the detector is much more complex than that for the well known cases of pure sine waves (i.e. classical noncoherent detection) and narrowband signals. An interpretation of the optimal processing is presented, and several implementations are discussed. The results have application to the noncoherent detection of optical square waves.
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On Algorithms for Generating Computationally Simple Piecewise Linear Classifiers
1989-05-01
suffers. - Waveform classification, e.g. speech recognition, seismic analysis (i.e. discrimination between earthquakes and nuclear explosions), target...assuming Gaussian distributions (B-G) d) Bayes classifier with probability densities estimated with the k-N-N method (B- kNN ) e) The -arest neighbour...range of classifiers are chosen including a fast, easy computable and often used classifier (B-G), reliable and complex classifiers (B- kNN and NNR
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Model weights and the foundations of multimodel inference
Link, W.A.; Barker, R.J.
2006-01-01
Statistical thinking in wildlife biology and ecology has been profoundly influenced by the introduction of AIC (Akaike?s information criterion) as a tool for model selection and as a basis for model averaging. In this paper, we advocate the Bayesian paradigm as a broader framework for multimodel inference, one in which model averaging and model selection are naturally linked, and in which the performance of AIC-based tools is naturally evaluated. Prior model weights implicitly associated with the use of AIC are seen to highly favor complex models: in some cases, all but the most highly parameterized models in the model set are virtually ignored a priori. We suggest the usefulness of the weighted BIC (Bayesian information criterion) as a computationally simple alternative to AIC, based on explicit selection of prior model probabilities rather than acceptance of default priors associated with AIC. We note, however, that both procedures are only approximate to the use of exact Bayes factors. We discuss and illustrate technical difficulties associated with Bayes factors, and suggest approaches to avoiding these difficulties in the context of model selection for a logistic regression. Our example highlights the predisposition of AIC weighting to favor complex models and suggests a need for caution in using the BIC for computing approximate posterior model weights.
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Conceptual Design of a Chesapeake Bay Environmental Observatory (CBEO)
NASA Astrophysics Data System (ADS)
Ball, W. P.; di Toro, D.; Gross, T. F.; Kemp, W. M.; Burns, R.; Piasecki, M.; Zaslavsky, I.; Cuker, B. E.; Murray, L.
2006-12-01
A new project is underway to develop and deploy a Chesapeake Bay Environmental Observatory (CBEO), which is intended to serve as a prototype of cyberinfrastructure (CI) for environmental observatory networks (EONs) that will demonstrate the transformative power of CI. The CBEO will be developed by a team of highly qualified computer scientists, ecologists, oceanographers and environmental engineers with a track record of working together on environmental observatory projects and complex cross-discipline research efforts. The project approach has been organized around the following four concurrent interacting elements, which follow the acronym "NETS": (1) The CBEO:N group will incorporate the test bed CI into the national EONs by constructing a GEON-based node for the CBEO. This will entail resolving complex cross-disciplinary issues of semantics, syntax and inter- operability as well as developing new shared CI tools for data assimilation and interpolation. (2) CBEO:E is the education element and will use the CBEO to translate observational science for public consumption. Direct participation of multicultural students and a K-12 teacher are planned. The test-bed and network components (described below and above) will provide the focus of five workshops for users, managers and science educators; (3) Prior to full integration via CBEO:N, CBEO:T will rapidly construct a locally accessible CBEO test-bed prototype that will integrate a subset of currently available large data sets characterized by multiple variables and widely disparate time and space scales ? grab and continuous sampling at fixed stations, undulating towed sensors, and satellite and aircraft remote sensing. A novel feature will be the inclusion of the fifteen year (1986-2000) simulated data from the Bay-wide fine spatial (1-10 km) and temporal (0.02-1 hr) scale hydrodynamic and water quality model. CBEO:T will serve initially as the development platform for data integration, interpolation, and visualization. (4) The driving force and context for the effort will be provided by the environmental science element, CBEO:S. CBEO:S will use CBEO:T and CBEO:N to address unresolved questions of anthropogenic and climatic factors controlling hypoxia in Chesapeake Bay, a problem shared with many other estuaries and whose consequences are severe and long lasting. The CBEO:S and CBEO:E teams will test the CBEO capabilities, suggest modifications, and provide timely user feedback. Overall, the project intends to demonstrate the power of blending CI and domain science to produce new and exciting scientific insights and engineering tools. The CI will produce a joining of disparate and incommensurable Chesapeake Bay data sets, while also providing shared CI developments to serve a multi- disciplinary research community through an observation node that is a member of all EONs currently under development.
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Adaptive selection and validation of models of complex systems in the presence of uncertainty
DOE Office of Scientific and Technical Information (OSTI.GOV)
Farrell-Maupin, Kathryn; Oden, J. T.
This study describes versions of OPAL, the Occam-Plausibility Algorithm in which the use of Bayesian model plausibilities is replaced with information theoretic methods, such as the Akaike Information Criterion and the Bayes Information Criterion. Applications to complex systems of coarse-grained molecular models approximating atomistic models of polyethylene materials are described. All of these model selection methods take into account uncertainties in the model, the observational data, the model parameters, and the predicted quantities of interest. A comparison of the models chosen by Bayesian model selection criteria and those chosen by the information-theoretic criteria is given.
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ETR COMPLEX. CAMERA FACING EAST. FROM LEFT TO RIGHT: ETRCRITICAL ...
ETR COMPLEX. CAMERA FACING EAST. FROM LEFT TO RIGHT: ETR-CRITICAL FACILITY BUILDING, ETR CONTROL BUILDING (ATTACHED TO HIGH-BAY ETR), ETR, ONE-STORY SECTION OF ETR BUILDING, ELECTRICAL BUILDING, COOLING TOWER PUMP HOUSE, COOLING TOWER. COMPRESSOR AND HEAT EXCHANGER BUILDING ARE PARTLY IN VIEW ABOVE ETR. DARK-COLORED DUCTS PROCEED FROM GROUND CONNECTION TO ETR WASTE GAS STACK. OTHER STACK IS MTR STACK WITH FAN HOUSE IN FRONT OF IT. RECTANGULAR STRUCTURE NEAR TOP OF VIEW IS SETTLING BASIN. INL NEGATIVE NO. 56-4102. Unknown Photographer, ca. 1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID
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ETR, TRA642. ETR COMPLEX NEARLY COMPLETE. CAMERA FACES NORTHWEST, PROBABLY ...
ETR, TRA-642. ETR COMPLEX NEARLY COMPLETE. CAMERA FACES NORTHWEST, PROBABLY FROM TOP DECK OF COOLING TOWER. SHADOW IS CAST BY COOLING TOWER UNITS OFF LEFT OF VIEW. HIGH-BAY REACTOR BUILDING IS SURROUNDED BY ITS ATTACHED SERVICES: ELECTRICAL (TRA-648), HEAT EXCHANGER (TRA-644 WITH U-SHAPED YARD), AND COMPRESSOR (TRA-643). THE CONTROL BUILDING (TRA-647) ON THE NORTH SIDE IS HIDDEN FROM VIEW. AT UPPER RIGHT IS MTR BUILDING, TRA-603. INL NEGATIVE NO. 56-3798. Jack L. Anderson, Photographer, 11/26/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID
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Adaptive selection and validation of models of complex systems in the presence of uncertainty
Farrell-Maupin, Kathryn; Oden, J. T.
2017-08-01
This study describes versions of OPAL, the Occam-Plausibility Algorithm in which the use of Bayesian model plausibilities is replaced with information theoretic methods, such as the Akaike Information Criterion and the Bayes Information Criterion. Applications to complex systems of coarse-grained molecular models approximating atomistic models of polyethylene materials are described. All of these model selection methods take into account uncertainties in the model, the observational data, the model parameters, and the predicted quantities of interest. A comparison of the models chosen by Bayesian model selection criteria and those chosen by the information-theoretic criteria is given.
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2012-09-20
CAPE CANAVERAL, Fla. – Inside Orbiter Processing Facility-2 at NASA’s Kennedy Space Center in Florida, a view of space shuttle Atlantis’ nose cone is shown as the payload bay doors are closed for the final time. The orbiter is undergoing final preparations for its transfer to the Kennedy Space Center Visitor complex targeted for November. The work is part of Transition and Retirement of the remaining shuttle. Atlantis is being prepared for public display at the visitor complex. Over the course of its 26-year career, Atlantis spent 293 days in space during 33 missions. For more information, visit http://www.nasa.gov/transition. Photo credit: NASA/Jim Grossmann
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2012-09-20
CAPE CANAVERAL, Fla. – Inside Orbiter Processing Facility-2 at NASA’s Kennedy Space Center in Florida, a view of space shuttle Atlantis’ nose cone is shown as the payload bay doors are closed for the final time. The orbiter is undergoing final preparations for its transfer to the Kennedy Space Center Visitor complex targeted for November. The work is part of Transition and Retirement of the remaining shuttle. Atlantis is being prepared for public display at the visitor complex. Over the course of its 26-year career, Atlantis spent 293 days in space during 33 missions. For more information, visit http://www.nasa.gov/transition. Photo credit: NASA/Jim Grossmann
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Multidisciplinary Investigations of Submarine Flow to Biscayne Bay, Florida
NASA Astrophysics Data System (ADS)
Halley, R. B.; Reich, C. D.; Swarzenski, P. W.; Langevin, C. D.
2005-05-01
Biscayne Bay and Biscayne National Park (BNP) are located next to the Miami-Dade urban complex and are adjacent to the Dade County South Dade Landfill Facility and the Miami-Dade Water and Sewer South District Plant. The base of the landfill is lined to separate it from the underlying Miami Limestone, the host rock for the surficial Biscayne Aquifer. The sewage-treatment facility injects treated sewage into the lower Florida Aquifer (750 m) that is overlain by an aquitard termed the Middle Confining Unit (450 m). The Biscayne Aquifer (up to 50 m thick) borders the western margin of BNP, and the Floridan Aquifer underlies the entire park. There is concern about leakage of contaminated aquifer water into BNP and its potential effects on water quality. Groundwater flux to Biscayne Bay is being studied using pressure measurements and geochemical analyses from submarine wells, electromagnetic seepage meters, streaming resistivity profiling, and local and regional model simulations. Both seepage meters and water analyses provide point information that can be placed into the regional context provided by flow models and geochemical and geophysical profiling, which, in turn, constrain the groundwater contribution. Water samples were collected approximately quarterly from August 2002 until March 2004 from submarine wells along a transect through Biscayne Bay and across the reef to the shelf edge. Samples were analyzed for conductivity (salinity), dissolved oxygen, temperature, redox potential, nutrients, metals, strontium isotopes, radon, sulfate, and wastewater compounds. Low-salinity water was identified from nearshore wells and indicates seepage from the Biscayne Aquifer and/or surface-water intrusion into the rocks along western Biscayne Bay. Analyses of water samples (n = 109) collected from wells across the Florida shelf show no consistent evidence of wastewater contaminants occurring in groundwater beneath BNP. No significant leakage from the Floridan Aquifer (characterized by low strontium-isotope ratios) was detected in the wells. The groundwater beneath the shelf can be characterized as reduced seawater, modified by microbial respiration to remove oxygen, and interacting with sediments and minerals in the host limestone. The data from submarine well samples are consistent with groundwater model results that indicate a narrow zone of discharge along the western margin of Biscayne Bay. This zone varies in width from 100 to 1000 m along the coast. A seepage meter placed in this zone during March 2004 recorded an average flow of 23 cm/day. Submarine discharge is estimated to be about 6% of the surface-water flow to Biscayne Bay, and almost all of this is in the northern half of the bay, where shoreline and water-table elevations are greatest. Saltwater intrusion extends farther inland in the southern portion of the bay, where water-table and coastal elevations are low. Shoreline-parallel radon-222 profiles also indicate more seepage in the north than south, but suggest low-salinity water extends between 1 and 2 km offshore. Resistivity profiling provided a fourth technique (along with wells, models, and radon) that documents low-salinity water along the coast, particularly toward the northern bay. Resistivity is the only methodology that indicates presence of brackish water 5 km offshore, an observation that requires verification. Interdisciplinary approaches that estimate submarine flow to this tropical estuary are helping reinforce observations made by complimentary methods, while clearly identifying other observations as worthy of further investigation and verification.
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Code of Federal Regulations, 2012 CFR
2012-07-01
..., Carquinez Strait, and Suisun Bay, CA. (a) Regulated area. The following area is established as a moving... Francisco Bay, San Pablo Bay, Carquinez Strait, and Suisun Bay, CA. 165.1182 Section 165.1182 Navigation and... vessels transit from a line drawn between San Francisco Main Ship Channel buoys 7 and 8 (LLNR 4190 & 4195...
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Code of Federal Regulations, 2011 CFR
2011-07-01
..., Carquinez Strait, and Suisun Bay, CA. (a) Regulated area. The following area is established as a moving... Francisco Bay, San Pablo Bay, Carquinez Strait, and Suisun Bay, CA. 165.1182 Section 165.1182 Navigation and... vessels transit from a line drawn between San Francisco Main Ship Channel buoys 7 and 8 (LLNR 4190 & 4195...
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Code of Federal Regulations, 2013 CFR
2013-07-01
..., Carquinez Strait, and Suisun Bay, CA. (a) Regulated area. The following area is established as a moving... Francisco Bay, San Pablo Bay, Carquinez Strait, and Suisun Bay, CA. 165.1182 Section 165.1182 Navigation and... vessels transit from a line drawn between San Francisco Main Ship Channel buoys 7 and 8 (LLNR 4190 & 4195...
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Code of Federal Regulations, 2010 CFR
2010-07-01
..., Carquinez Strait, and Suisun Bay, CA. (a) Regulated area. The following area is established as a moving... Francisco Bay, San Pablo Bay, Carquinez Strait, and Suisun Bay, CA. 165.1182 Section 165.1182 Navigation and... vessels transit from a line drawn between San Francisco Main Ship Channel buoys 7 and 8 (LLNR 4190 & 4195...
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Code of Federal Regulations, 2014 CFR
2014-07-01
..., Carquinez Strait, and Suisun Bay, CA. (a) Regulated area. The following area is established as a moving... Francisco Bay, San Pablo Bay, Carquinez Strait, and Suisun Bay, CA. 165.1182 Section 165.1182 Navigation and... vessels transit from a line drawn between San Francisco Main Ship Channel buoys 7 and 8 (LLNR 4190 & 4195...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-06-28
...-AA00 Safety Zone; Independence Day Fireworks Celebration for the City of Half Moon Bay, Half Moon Bay... temporary safety zone in the navigable waters of Half Moon Bay, off of Pillar Point Harbor beach, Half Moon Bay, CA in support of the Independence Day Fireworks Celebration for the City of Half Moon Bay...
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Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety and Security Zones; Tall Ships Challenge 2010; Great Lakes; Cleveland, OH; Bay City, MI; Duluth, MN; Green Bay, WI; Sturgeon Bay...; Cleveland, OH; Bay City, MI; Duluth, MN; Green Bay, WI; Sturgeon Bay, WI; Chicago, IL; Erie, PA. (a...
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Page, Norman J; Talkington, Raymond W.
1984-01-01
Samples of spinel lherzolite, harzburgite, dunite, and chromitite from the Bay of Islands, Lewis Hills, Table Mountain, Advocate, North Arm Mountain, White Hills Periodite Point Rousse, Great Bend and Betts Cove ophiolite complexes in Newfoundland were analyzed for the platinum-group elements (PGE) Pd, Pt, Rh, Ru and Ir. The ranges of concentration (in ppb) observed for all rocks are: less than 0. 5 to 77 (Pd), less than 1 to 120 (Pt), less than 0. 5 to 20 (Rh), less than 100 to 250 (Ru) and less than 20 to 83 (Ir). Chondrite-normalized PGE ratios suggest differences between rock types and between complexes. Samples of chromitite and dunite show relative enrichment in Ru and Ir and relative depletion in Pt and Pd.
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Ager, Thomas A.
2000-01-01
Pollen records from two sites on the north shore of Kachemak Bay, south-central Alaska, provide the first radiocarbon-dated histories of postglacial vegetation development for southern Cook Inlet. During the late Wisconsin glacial interval, glaciers covered most of Cook Inlet. Deglaciation of Kachemak Bay began prior to 13,000 yr B.P. Pollen evidence indicates that a pioneering herbaceous tundra began to develop by 12,800 yr B.P., but was soon replaced by a shrub tundra of dwarf birch (Betula), Ericales (Ericaceae and Empetrum) and willows (Salix).By 9,500 yr B.P., a shrub-dominated vegetation of alders (Alnus) and willows, with some deciduous trees (Populus spp.) quickly developed and persisted until late Holocene time. By about 4,000–3,800 yr B.P., spruce trees (Picea glauca and (or) P. mariana) from the interior boreal forests reached the northern Kachemak Bay area from upper Cook Inlet and began to displace the alder-dominated vegetation. A coastal forest of Sitka spruce (Picea sitchensis) began to colonize Kachemak Bay more recently, about 1,650 yr B.P. (minimum age), apparently from sources in Prince William Sound to the east. Where Sitka spruce came into proximity with boreal white spruce (Picea glauca), hybridization occurred, ultimately influencing the spruce forests over a large area of the Kenai Lowland. Some key findings of this study are: (1) the Kachemak Bay-area pollen records do not display persuasive evidence for a “Younger Dryas” cold, dry interval ca. 11,000–10,000 yr B.P. that has been reported from pollen records on Kodiak Island (Gulf of Alaska) and Pleasant Island (southeastern Alaska); (2) at least one species of alder may have survived in refugia in south-central Alaska during the last glacial interval; (3) coastal forests appear to be still migrating west along the coast of south-central Alaska, but their spread northward is being limited by drier, colder winter climates; (4) the mountainous topography of south-central Alaska, coupled with varying degrees of maritime climate influence, create complex patterns of climates and vegetation in the region, in both the past and present.
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2015-01-01
Coral reefs are now subject to global threats and influences from numerous anthropogenic sources. Foraminifera, a group of unicellular shelled organisms, are excellent indicators of water quality and reef health. Thus we studied a set of samples taken in 1992 to provide a foraminiferal baseline for future studies of environmental change. Our study provides the first island-wide analysis of shallow benthic foraminifera from around Moorea (Society Archipelago). We analyzed the composition, species richness, patterns of distribution and abundance of unstained foraminiferal assemblages from bays, fringing reefs, nearshore and back- and fore-reef environments. A total of 380 taxa of foraminifera were recorded, a number that almost doubles previous species counts. Spatial patterns of foraminiferal assemblages are characterized by numerical abundances of individual taxa, cluster groups and gradients of species richness, as documented by cluster, Fisher α, ternary plot and Principal Component Analyses (PCA). The inner bay inlets are dominated by stress-tolerant, mostly thin-shelled taxa of Bolivina, Bolivinella, Nonionoides, Elongobula, and Ammonia preferring low-oxygen and/or nutrient-rich habitats influenced by coastal factors such as fresh-water runoff and overhanging mangroves. The larger symbiont-bearing foraminifera (Borelis, Amphistegina, Heterostegina, Peneroplis) generally live in the oligotrophic, well-lit back- and fore-reef environments. Amphisteginids and peneroplids were among the few taxa found in the bay environments, probably due to their preferences for phytal substrates and tolerance to moderate levels of eutrophication. The fringing reef environments along the outer bay are characterized by Borelis schlumbergeri, Heterostegina depressa, Textularia spp. and various miliolids which represent a hotspot of diversity within the complex reef-lagoon system of Moorea. The high foraminiferal Fisher α and species richness diversity in outer bay fringing reefs is consistent with the disturbance-mosaic (microhabitat heterogeneity) hypothesis. Calculations of the FORAM Index (FI), a single metric index to assess reef vitality, indicate that all fore- and most back-reef environments support active carbonate accretion and provide habitat suitability for carbonate producers dependent on algal symbiosis. Lowest suitability values were recorded within the innermost bays, an area where natural and increasing anthropogenic influences continue to impact the reefs. The presence of habitat specific assemblages and numerical abundance values of individual taxa show that benthic foraminifera are excellent recorders of environmental perturbations and good indicators useful in modern and ancient ecological and environmental studies. PMID:26710320
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Collisional Tectonics in the St. Elias Orogen, Alaska Observed by GPS
NASA Astrophysics Data System (ADS)
Elliott, J.; Freymueller, J. T.; Larsen, C. F.
2008-12-01
The rugged topography of the St. Elias orogen of southern Alaska and the adjacent region of Canada is the result of the on-going collision of the Yakutat block with southern Alaska. Nearly 45 mm/yr of NW-SE directed convergence from the collision is currently accommodated within the St. Elias orogen. A key to understanding this complex collisional boundary is knowing the locations of the structures taking up the convergence. GPS provides a snapshot of the present-day strain field and helps to delineate active structures. As part of the St. Elias Erosion/Tectonics Project (STEEP), we re-surveyed 70 campaign GPS sites across the St. Elias orogen during the summer of 2008. Strain rates derived from our GPS data highlight several areas within the St. Elias orogen. The highest strain rates occur across Icy Bay and the western edge of the Malaspina Glacier. Rates there approach -1 microstrain/yr, a value higher than that observed in the Himalaya. Lower, but still significant, strain rates of about -0.2 microstrain/yr extend north from Icy Bay to the region surrounding Mt. St. Elias. The second major focus of compressive strain in the orogen is centered over the Yakataga fold-and-thrust belt. Strain rates there are in the range of -0.40 to -0.50 microstrain/yr. Little significant strain is seen across the Bagley icefield or to the north of that feature. These results suggest that most of the convergence across the St. Elias orogen is currently accommodated on structures located south of the Bagely icefield, specifically in the Icy Bay, upper Malaspina/Mt. St. Elias, and Yakataga fold-and-thrust belt regions. We use block modeling techniques to describe the tectonic elements of the St. Elias orogen and connect them with the tectonic regime in southeast Alaska. Our preliminary results indicate that a single thrust fault through Icy Bay cannot explain the data there; multiple NW and N directed thrust faults through Icy Bay, along the western edge of the Malaspina Glacier, and between Icy Bay and Mt. St. Elias are required. Over half of the relative convergence between the Yakutat block and southern Alaska may be accommodated by elastic strain accumulation on these faults.
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Deposition, erosion, and bathymetric change in South San Francisco Bay: 1858-1983
Foxgrover, Amy C.; Higgins, Shawn A.; Ingraca, Melissa K.; Jaffe, Bruce E.; Smith, Richard E.
2004-01-01
Since the California Gold Rush of 1849, sediment deposition, erosion, and the bathymetry of South San Francisco Bay have been altered by both natural processes and human activities. Historical hydrographic surveys can be used to assess how this system has evolved over the past 150 years. The National Ocean Service (NOS) (formerly the United States Coast and Geodetic Survey (USCGS), collected five hydrographic surveys of South San Francisco Bay from 1858 to 1983. Analysis of these surveys enables us to reconstruct the surface of the bay floor for each time period and quantify spatial and temporal changes in deposition, erosion, and bathymetry. The creation of accurate bathymetric models involves many steps. Sounding data was obtained from the original USCGS and NOS hydrographic sheets and were supplemented with hand drawn depth contours. Shorelines and marsh areas were obtained from topographic sheets. The digitized soundings and shorelines were entered into a Geographic Information System (GIS), and georeferenced to a common horizontal datum. Using surface modeling software, bathymetric grids with a horizontal resolution of 50 m were developed for each of the five hydrographic surveys. Prior to conducting analyses of sediment deposition and erosion, we converted all of the grids to a common vertical datum and made adjustments to correct for land subsidence that occurred from 1934 to 1967. Deposition and erosion that occurred during consecutive periods was then computed by differencing the corrected grids. From these maps of deposition and erosion, we calculated volumes and rates of net sediment change in the bay. South San Francisco Bay has lost approximately 90 x 106 m3 of sediment from 1858 to 1983; however within this timeframe there have been periods of both deposition and erosion. During the most recent period, from 1956 to 1983, sediment loss approached 3 x 106 m3/yr. One of the most striking changes that occurred from 1858 to 1983 was the conversion of more than 80% of the tidal marsh to salt ponds, agricultural, and urban areas. In addition, there has been a decline of approximately 40% in intertidal mud flat area. Restoration of these features will require a detailed understanding of the morphology and sediment sources of this complex system.
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Temporal shifts in reef lagoon sediment composition, Discovery Bay, Jamaica
NASA Astrophysics Data System (ADS)
Perry, Christopher T.; Taylor, Kevin G.; Machent, Philip G.
2006-03-01
Discovery Bay, north Jamaica, forms a large (1.5 km wide), deep (up to 56 m) embayment that acts as a sink for reef-derived and lagoonal carbonate sediments. Since the mid-1960s, the bay has also provided a sink for inputs of bauxite sediment that are spilled during loading at a boat terminal constructed within Discovery Bay. Bauxite has accumulated across much of the southern section of the bay with surficial sediments presently composed of up to 35 weight% non-carbonate. Cores recovered from sites on the western side of the bay provide a stratigraphic record of this history of bauxite contamination across water depths from 5 to 25 m. The bauxite-influenced upper sediment horizons are clearly visible in each core from the distinctive red-brown colouration of the sediment. These sediments are composed of approximately 10% non-carbonate (bauxite) and have Fe contents of around 2-3000 μg/g (up to 7000 μg/g). The thickness of this upper bauxite-contaminated sequence increases down transect (approximately 18 cm in the shallowest core, to around 47 cm in the deepest core), and in each core overlies a sequence of 'clean' lagoon carbonates. These typically are poorly sorted carbonate sands with variable amounts of coral rubble. Down-core data on CaCO 3 and Fe content provide a chemical record of decreasing sediment contamination with depth, with the lower 'clean' carbonates composed of only around 2% non-carbonate and <700 μg/g Fe. Down-core sediment-constituent data also indicate significant changes in sediment production at the shallowest sites. At depths of 5 and 10 m, sediment assemblages have shifted from diverse assemblages of coral, mollusc, Amphiroa and Halimeda in the clean lagoon sands, to assemblages dominated by Halimeda and Amphiroa within the surficial sediments. At the deeper sites, no major down-core shifts in sediment constituents occur. These sites thus record a rather complex history of changes in sediment composition and chemistry. Clear shifts in chemistry and stratigraphy occur in all the cores and reflect progressive bauxite contamination in the near-surface horizons. These inputs, however, do not appear to have directly affected carbonate production, since the major constituent changes appear to be a response to more regional declines in coral community and reef status.
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Fajemila, Olugbenga T; Langer, Martin R; Lipps, Jere H
2015-01-01
Coral reefs are now subject to global threats and influences from numerous anthropogenic sources. Foraminifera, a group of unicellular shelled organisms, are excellent indicators of water quality and reef health. Thus we studied a set of samples taken in 1992 to provide a foraminiferal baseline for future studies of environmental change. Our study provides the first island-wide analysis of shallow benthic foraminifera from around Moorea (Society Archipelago). We analyzed the composition, species richness, patterns of distribution and abundance of unstained foraminiferal assemblages from bays, fringing reefs, nearshore and back- and fore-reef environments. A total of 380 taxa of foraminifera were recorded, a number that almost doubles previous species counts. Spatial patterns of foraminiferal assemblages are characterized by numerical abundances of individual taxa, cluster groups and gradients of species richness, as documented by cluster, Fisher α, ternary plot and Principal Component Analyses (PCA). The inner bay inlets are dominated by stress-tolerant, mostly thin-shelled taxa of Bolivina, Bolivinella, Nonionoides, Elongobula, and Ammonia preferring low-oxygen and/or nutrient-rich habitats influenced by coastal factors such as fresh-water runoff and overhanging mangroves. The larger symbiont-bearing foraminifera (Borelis, Amphistegina, Heterostegina, Peneroplis) generally live in the oligotrophic, well-lit back- and fore-reef environments. Amphisteginids and peneroplids were among the few taxa found in the bay environments, probably due to their preferences for phytal substrates and tolerance to moderate levels of eutrophication. The fringing reef environments along the outer bay are characterized by Borelis schlumbergeri, Heterostegina depressa, Textularia spp. and various miliolids which represent a hotspot of diversity within the complex reef-lagoon system of Moorea. The high foraminiferal Fisher α and species richness diversity in outer bay fringing reefs is consistent with the disturbance-mosaic (microhabitat heterogeneity) hypothesis. Calculations of the FORAM Index (FI), a single metric index to assess reef vitality, indicate that all fore- and most back-reef environments support active carbonate accretion and provide habitat suitability for carbonate producers dependent on algal symbiosis. Lowest suitability values were recorded within the innermost bays, an area where natural and increasing anthropogenic influences continue to impact the reefs. The presence of habitat specific assemblages and numerical abundance values of individual taxa show that benthic foraminifera are excellent recorders of environmental perturbations and good indicators useful in modern and ancient ecological and environmental studies.
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NASA Astrophysics Data System (ADS)
Bodger, K. L.; Pettinga, J. R.; Barnes, P. M.
2006-12-01
More than 4000 km2 of high quality bathymetric and backscatter imaging of the Poverty Bay Indentation across the northern part of the Hikurangi subduction zone provide new insights into the relationship between seafloor morphology and active structures. The swath bathymetry extends from the edge of the continental shelf to the abyssal plain, at depths of between 100 to 3500 metres. The origin of the slope re-entrant is inferred to be related to multiple seamount impacts, and these collisions have initiated numerous large-scale gravitational collapse structures, multiple debris flow and avalanche deposits, which range in down-slope length from a few hundred metres to more than 40 km. The Poverty Bay Indentation has been simultaneously eroded by canyon systems that exhibit many of the features of incised river systems onshore. The swath images are complemented by the availability of excellent high-quality processed multi-channel seismic reflection data, single channel high-resolution 3.5 kHz seismic reflection data, as well as a limited number of core samples. Seismic reflection profiles and seafloor morphology are used to provide three morpho-structural sections. The comparison of these sections highlights the different effects of seamount subduction on the evolution of the margin and the re-entrant. The northern two sections are located to the north side of the re-entrant and reveal the role of seamount impact on the interrelationship between the structural evolution with respect to seafloor morphology. Here the development of an over-steepened margin with fault reactivation, inversion and over- printing leads to very complex structural styles of deformation and geometry in both seismic reflection profiles and seafloor morphology. There is evidence of an older, inactive thrust front buried beneath the upper and mid- slope basins. Beneath the mid-slope a subducted seamount is revealed by the presence of relief on the subduction interface and associated structural complexity in the over-riding wedge. The Poverty Bay canyon represents a structural transition zone coinciding with the re-entrant. The accretionary slope south of the re- entrant conforms more closely to the classic accretionary slope style of deformation. Backthrusts in this section propagate from a much shallower level than in the northern sections. Inversion is commonly observed in the mid slope and continental shelf basins, particularly to the south. Initial interpretations indicate that: i) seamount impact significantly influences the structural evolution, and submarine geomorphology of the inboard slope of the Hikurangi subduction zone, including the generation of large-scale gravitational collapse features; ii) the large gully systems located at the upper shelf slope boundary represent the most likely source areas for the multiple mega debris flows recognised from seafloor morphology and in seismic sections; iii) there exists a complex interaction between the evolving thrust-driven submarine ridges, ponded slope basins and the structural geometry and evolution of the near-surface fault zones (imbrication); iv) the submarine canyons may initiate complex patterns of fault zone segmentation and displacement transfer within the accretionary slope; and v) seamount subduction and subsequent instability of the margin may directly result in tsunami generation.
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Time scales of circulation and mixing processes of San Francisco Bay waters
Walters, R.A.; Cheng, R.T.; Conomos, T.J.
1985-01-01
Conceptual models for tidal period and low-frequency variations in sea level, currents, and mixing processes in the northern and southern reaches of San Francisco Bay describe the contrasting characteristics and dissimilar processes and rates in these embayments: The northern reach is a partially mixed estuary whereas the southern reach (South Bay) is a tidally oscillating lagoon with density-driven exchanges with the northern reach. The mixed semidiurnal tides are mixtures of progressive and standing waves. The relatively simple oscillations in South Bay are nearly standing waves, with energy propagating down the channels and dispersing into the broad shoal areas. The tides of the northern reach have the general properties of a progressive wave but are altered at the constriction of the embayments and gradually change in an upstream direction to a mixture of progressive and standing waves. The spring and neap variations of the tides are pronounced and cause fortnightly varying tidal currents that affect mixing and salinity stratification in the water column. Wind stress on the water surface, freshwater inflow, and tidal currents interacting with the complex bay configuration are the major local forcing mechanisms creating low-frequency variations in sea level and currents. These local forcing mechanisms drive the residual flows which, with tidal diffusion, control the water-replacement rates in the estuary. In the northern reach, the longitudinal density gradient drives an estuarine circulation in the channels, and the spatial variation in tidal amplitude creates a tidally-driven residual circulation. In contrast, South Bay exhibits a balance between wind-driven circulation and tidally-driven residual circulation for most of the year. During winter, however, there can be sufficient density variations to drive multilayer (2 to 3) flows in the channel of South Bay. Mixing models (that include both diffusive and dispersive processes) are based on time scales associated with salt variations at the boundaries and those associated with the local forcing mechanisms, while the spatial scales of variations are dependent upon the configuration of the embayments. In the northern reach, where the estuarine circulation is strong, the salt flux is carried by the mean advection of the mean salt field. Where large salinity gradients are present, the tidal correlation part of the salt flux is of the same order as the advective part. Our knowledge of mixing and exchange rates in South Bay is poor. As this embayment is nearly isohaline, the salt flux is dominated entirely by the mean advection of the mean salt field. During and after peaks in river discharge, water mixing becomes more dynamic, with a strong density-driven current creating a net exchange of both water mass and salt. These exchanges are stronger during neap tides. Residence times of the water masses vary seasonally and differ between reaches. In the northern reach, residence times are on the order of days for high winter river discharge and of months for summer periods. The residence times for South Bay are fairly long (on the order of several months) during summer, and typically shorter (less than a month) during winter when density-driven exchanges occur. ?? 1985 Dr W. Junk Publishers.
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33 CFR 110.78 - Sturgeon Bay, Sturgeon Bay, Wis.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Sturgeon Bay, Sturgeon Bay, Wis. 110.78 Section 110.78 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.78 Sturgeon Bay, Sturgeon Bay, Wis. (a) Area 1...
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33 CFR 110.78 - Sturgeon Bay, Sturgeon Bay, Wis.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Sturgeon Bay, Sturgeon Bay, Wis. 110.78 Section 110.78 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.78 Sturgeon Bay, Sturgeon Bay, Wis. (a) Area 1...
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33 CFR 110.78 - Sturgeon Bay, Sturgeon Bay, Wis.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Sturgeon Bay, Sturgeon Bay, Wis. 110.78 Section 110.78 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.78 Sturgeon Bay, Sturgeon Bay, Wis. (a) Area 1...
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33 CFR 110.78 - Sturgeon Bay, Sturgeon Bay, Wis.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Sturgeon Bay, Sturgeon Bay, Wis. 110.78 Section 110.78 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.78 Sturgeon Bay, Sturgeon Bay, Wis. (a) Area 1...
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75 FR 54771 - Safety Zone; Thunder on the Bay, Chesapeake Bay, Buckroe Beach Park, Hampton, VA
Federal Register 2010, 2011, 2012, 2013, 2014
2010-09-09
...-AA00 Safety Zone; Thunder on the Bay, Chesapeake Bay, Buckroe Beach Park, Hampton, VA AGENCY: Coast... safety zone on the navigable waters of Chesapeake Bay in Hampton, VA in support of the Thunder on the Bay.... 0 2. Add Sec. 165.T05-0755 to read as follows: Sec. 165.T05-0755 Safety Zone; Thunder on the Bay...
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Reconnaissance geologic map of the Kuskokwim Bay region, southwest Alaska
Wilson, Frederic H.; Hults, Chad P.; Mohadjer, Solmaz; Coonrad, Warren L.
2013-01-01
The rocks of the map area range from Proterozoic age metamorphic rocks of the Kanektok metamorphic complex (Kilbuck terrane) to Quaternary age mafic volcanic rocks of Nunivak Island. The map area encompasses much of the type area of the Togiak-Tikchik Complex. The geologic maps used to construct this compilation were, for the most part, reconnaissance studies done in the time period from the 1950s to 1990s. Pioneering work in the map area by J.M. Hoare and W.L. Coonrad forms the basis for much of this map, either directly or as the stepping off point for later studies compiled here. Physiographically, the map area ranges from glaciated mountains, as much as 1,500 m high, in the Ahklun Mountains to the coastal lowlands of northern Bristol Bay and the Kuskokwim River delta. The mountains and the finger lakes (drowned fiords) on the east have been strongly affected by Pleistocene and Holocene glaciation. Within the map area are a number of major faults. The Togiak-Tikchik Fault and its extension to the northeast, the Holitna Fault, are considered extensions of the Denali fault system of central Alaska. Other sub-parallel faults include the Golden Gate, Sawpit, Goodnews, and East Kulukak Faults. Northwest-trending strike-slip faults crosscut and offset northeast-trending fault systems. Rocks of the area are assigned to a number of distinctive lithologic packages. Most distinctive among these packages are the high-grade metamorphic rocks of the Kanektok metamorphic complex or Kilbuck terrane, composed of a high-grade metamorphic orthogneiss core surrounded by greenschist and amphibolite facies schist, gneiss, and rare marble and quartzite. These rocks have yielded radiometric ages strongly suggestive of a 2.05 Ga emplacement age. Poorly known Paleozoic rocks, including Ordovician to Devonian and Permian limestone, are found east of the Kanektok metamorphic complex. A Triassic(?) ophiolite complex is on the southeast side of Kuskokwim Bay; otherwise only minor Triassic rock units are known. The most widespread rocks of the area are Jurassic and Early Cretaceous(?) volcanic and volcaniclastic rocks. The Kuskokwim Group flysch is restricted largely to the northeast part of the map area. It consists primarily of shelf and minor nearshore facies rocks. Primarily exposed in the lowlands west of the Ahklun Mountains, extensive latest Tertiary and Quaternary alkalic basalt flows and lesser pyroclastic rocks form much of the bedrock of the remaining area. On Saint Matthew Island, Cretaceous volcanic and pyroclastic rocks occur that are not found elsewhere within the map area. The Kuskokwim Group and older rocks, including on Saint Matthew Island, but not the Kanektok metamorphic complex, are intruded by widely dispersed Late Cretaceous and (or) Early Tertiary granitic rocks. Much of the lowland area is mantled by unconsolidated deposits that include glacial, alluvial and fluvial, marine, estuarine, and eolian deposits. These formed during several episodes of Quaternary glaciation.
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Aggregate Settling Velocities in San Francisco Estuary Margins
NASA Astrophysics Data System (ADS)
Allen, R. M.; Stacey, M. T.; Variano, E. A.
2015-12-01
One way that humans impact aquatic ecosystems is by adding nutrients and contaminants, which can propagate up the food web and cause blooms and die-offs, respectively. Often, these chemicals are attached to fine sediments, and thus where sediments go, so do these anthropogenic influences. Vertical motion of sediments is important for sinking and burial, and also for indirect effects on horizontal transport. The dynamics of sinking sediment (often in aggregates) are complex, thus we need field data to test and validate existing models. San Francisco Bay is well studied and is often used as a test case for new measurement and model techniques (Barnard et al. 2013). Settling velocities for aggregates vary between 4*10-5 to 1.6*10-2 m/s along the estuary backbone (Manning and Schoellhamer 2013). Model results from South San Francisco Bay shoals suggest two populations of settling particles, one fast (ws of 9 to 5.8*10-4 m/s) and one slow (ws of < 1*10-7 to 1.4*10-5 m/s) (Brand et al. 2015). While the open waters of San Francisco Bay and other estuaries are well studied and modeled, sediment and contaminants often originate from the margin regions, and the margins remain poorly characterized. We conducted a 24 hour field experiment in a channel slough of South San Francisco Bay, and measured settling velocity, turbulence and flow, and suspended sediment concentration. At this margin location, we found average settling velocities of 4-5*10-5 m/s, and saw settling velocities decrease with decreasing suspended sediment concentration. These results are consistent with, though at the low end of, those seen along the estuary center, and they suggest that the two population model that has been successful along the shoals may also apply in the margins.
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Van Heteren, S.; FitzGerald, D.M.; Barber, D.C.; Kelley, J.T.; Belknap, D.F.
1996-01-01
Ground-penetrating-radar (GPR) profiles calibrated with core data allow accurate assessments of coastal barrier volumes. We applied this procedure successfully to the barrier system along Saco Bay, Maine (USA), as part of a sediment-budget study that focused on present-day sand volumes in various coastal, shoreface, and inner-shelf lith-osomes, and on sand fluxes that have affected the volume or distribution of sand in these sediment bodies through time. On GPR profiles, the components of the barrier lithosome are readily differentiated from other facies, except where the radar signal is attenuated by brackish or salty groundwater. Significant differences between dielectric properties of the barrier lithosome and other units commonly result in strong boundary reflectors. The mostly sandy barrier sediments allow deep penetration of GPR waves, in contrast to finer-grained strata and till-covered bedrock. Within the Saco Bay barrier system, 22 ??3 x 106 m3 of sediment are unevenly distributed. Two-thirds of the total barrier volume is contained within the northern and southern ends of the study area, in the Pine Point spit and the Ferry Beach/Goosefare complex, respectively. The central area around Old Orchard Beach is locally covered by only a thin veneer of barrier sand, averaging <3 m, that unconformably overlies shallow pre-Holocene facies. The prominence of barrier-spit facies and the distribution pattern of back-barrier sediments indicate that a high degree of segmentation, governed by antecedent topography, has affected the development of the Saco Bay barrier system. The present-day configuration of the barrier and back-barrier region along Saco Bay, however, conceals much of its early compartmentalized character.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Mielczarek, W.; Copper, P.
1986-08-01
About 300 bioherms are known in the Llandoverian Manitoulin Formation of eastern Manitoulin Island. In the South Bay area, the large Leask Piont bioherm and Charlton Bay patch-reef complex lack a distinct skeletal growth framework. Bioherms consist of mudstone and wackestone, with isolated lenses of bafflestone, boundstone, floatstone. Fossils are scarce, but crinozoans and bryozoans comprise about 90% of the bioclasts. Other fauna include stromatoporoids, corals, brachiopods, gastropods, trilobites, and probable algae (algae are difficult to identify and may have played a significant role). Faunal ratios remained relatively constant during mound growth. Soft substrates with sedimentation rates of a fewmore » millimeters per year are suggested by bedding type and morphologic dominance of lamellar and tabular corals and stromatoporoids. An increased sedimentation rate, resulting from shoaling, is indicated by more overturned, broadly conical corals in the upper parts of the mounds. Shoaling may be responsible for cessation of mound growth. Lithoclasts are more common in the upper parts of the mounds. They formed when semiconsolidated muds were disturbed and redeposited during storms. Megarippled interreef surface areas, largely devoid of coral growth, indicate mud instability at Charlton Bay. Lack of suitable stable substrates may have hampered coral development. Dolomitization was postdepositional. The diagenetic sequence occurred in three stages: 1)selective pyritization and silicification, formation of an early muddy dolomite replacing the mud fraction of the dolostone, lithification and formation of rare calcite cement and neomorphic syntaxial rims; 2)clear, coarse dolomite replacing pore-filling calcite cement, syntaxial rims, and unaltered macrofossils, stylolitization, grain-to-grain dissolution; and 3)a late dolomite found mainly as fine rhombs in stylolites, solution seams, and intraskeletal pore space.« less
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Fish community responses to submerged aquatic vegetation in Maumee Bay, Western Lake Erie
Miller, Jacob; Kocovsky, Patrick; Wiegmann, Daniel; Miner, Jeffery G.
2018-01-01
Submerged aquatic vegetation (SAV) in clearwater systems simultaneously provides habitat for invertebrate prey and acts as refugia for small fishes. Many fishes in Lake Erie rely on shallow, heavily vegetated bays as spawning grounds and the loss or absence of which is known to reduce recruitment in other systems. The Maumee River and Maumee Bay, which once had abundant macrophyte beds, have experienced a decline of SAV and an increase in suspended solids (turbidity) over the last century due to numerous causes. To compare fish communities in open‐water (turbid) and in SAV (clearer water) habitats in this region, which is designated by the U.S. Environmental Protection Agency as an Area of Concern, and to indicate community changes that could occur with expansion of SAV habitat, we sampled a 300‐ha sector of northern Maumee Bay that contained both habitats. Using towed neuston nets through patches of each habitat, we determined that areas of SAV contained more species and a different species complex (based on the Jaccard index and the wetland fish index), than did the open‐water habitat (averaging 8.6 versus 5 species per net trawl). The SAV habitat was dominated by centrarchids, namely Largemouth Bass Micropterus salmoides, Bluegill Lepomis macrochirus, and Black Crappie Pomoxis nigromaculatus. Open‐water habitat was dominated by Spottail Shiner Notropis hudsonius, Gizzard Shad Dorosoma cepedianum, and White Perch Morone americana, an invasive species. These results indicate that restoration efforts aimed at decreasing turbidity and increasing the distribution of SAV could cause substantive shifts in the fish community and address important metrics for assessing the beneficial use impairments in this Area of Concern.
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77 FR 14276 - Regulated Navigation Area; Little Bay Bridge Construction, Little Bay, Portsmouth, NH
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-09
...-AA11 Regulated Navigation Area; Little Bay Bridge Construction, Little Bay, Portsmouth, NH AGENCY... under and surrounding the Little Bay and General Sullivan Bridges in order to facilitate construction of the Little Bay Bridge between Newington, NH and Dover, NH. This temporary interim rule is necessary to...
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Complexity, information loss, and model building: from neuro- to cognitive dynamics
NASA Astrophysics Data System (ADS)
Arecchi, F. Tito
2007-06-01
A scientific problem described within a given code is mapped by a corresponding computational problem, We call complexity (algorithmic) the bit length of the shortest instruction which solves the problem. Deterministic chaos in general affects a dynamical systems making the corresponding problem experimentally and computationally heavy, since one must reset the initial conditions at a rate higher than that of information loss (Kolmogorov entropy). One can control chaos by adding to the system new degrees of freedom (information swapping: information lost by chaos is replaced by that arising from the new degrees of freedom). This implies a change of code, or a new augmented model. Within a single code, changing hypotheses is equivalent to fixing different sets of control parameters, each with a different a-priori probability, to be then confirmed and transformed to an a-posteriori probability via Bayes theorem. Sequential application of Bayes rule is nothing else than the Darwinian strategy in evolutionary biology. The sequence is a steepest ascent algorithm, which stops once maximum probability has been reached. At this point the hypothesis exploration stops. By changing code (and hence the set of relevant variables) one can start again to formulate new classes of hypotheses . We call semantic complexity the number of accessible scientific codes, or models, that describe a situation. It is however a fuzzy concept, in so far as this number changes due to interaction of the operator with the system under investigation. These considerations are illustrated with reference to a cognitive task, starting from synchronization of neuron arrays in a perceptual area and tracing the putative path toward a model building.
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NASA Technical Reports Server (NTRS)
Moreno-Madrinan, Max Jacobo; Fischer, Andrew
2012-01-01
Satellite observation of phytoplankton concentration or chlorophyll-a is an important characteristic, critically integral to monitoring coastal water quality. However, the optical properties of estuarine and coastal waters are highly variable and complex and pose a great challenge for accurate analysis. Constituents such as suspended solids and dissolved organic matter and the overlapping and uncorrelated absorptions in the blue region of the spectrum renders the blue-green ratio algorithms for estimating chlorophyll-a inaccurate. Measurement of sun-induced chlorophyll fluorescence, on the other hand, which utilizes the near infrared portion of the electromagnetic spectrum, may provide a better estimate of phytoplankton concentrations. While modelling and laboratory studies have illustrated both the utility and limitations of satellite baseline algorithms based on the sun induced chlorophyll fluorescence signal, few have examined the empirical validity of these algorithms using a comprehensive long term in situ data set. In an unprecedented analysis of a long term (2003-2011) in situ monitoring data from Tampa Bay, Florida (USA), we assess the validity of the FLH product from the Moderate Resolution Imaging Spectrometer (MODIS) against chlorophyll ]a and a suite of water quality parameters taken in a variety of conditions throughout a large optically complex estuarine system. A systematic analysis of sampling sites throughout the bay is undertaken to understand how the relationship between FLH and in situ chlorophyll-a responds to varying conditions within the estuary including water depth, distance from shore and structures and eight water quality parameters. From the 39 station for which data was derived, 22 stations showed significant correlations when the FLH product was matched with in situ chlorophyll-alpha data. The correlations (r2) for individual stations within Tampa Bay ranged between 0.67 (n=28, pless than 0.01) and-0.457 (n=12, p=.016), indicating that for some areas within the Bay, FLH can be a good predictor of chlorophyll-alpha concentration and hence a useful tool for the analysis of water quality. Overall, the results show a 106% increase in the validity of chlorophyll -a concentration estimates using FLH over the standard the blue-green OC3M algorithm. This analysis also illustrates that the correlations between FLH and in situ chlorophyll -a measurements increases with increasing water depth and distance of the monitoring sites from both the shore and structures. However, due to confounding factors related to the complexity of the estuarine system, a linear improvement in the FLH to chlorophyll ]a relationship was not clearly noted with increasing depth and distance from shore alone. Correlations of FLH with turbidity, nutrients (total nitrogen and total phosphorous) biological oxygen demand, salinity, sea surface temperature correlated positively with FLH concentrations, while dissolved oxygen and pH showed negative correlations. Principle component analyses are employed to further describe the relationships between the multivariate water quality parameters and the FLH product. The majority of sites with higher and very significant correlations (pless than 0.01) also showed high correlation values for nutrients, turbidity and biological oxygen demand. These sites were on average in greater than seven meters of water and over five kilometers from shore. A thorough understanding of the relationship between the MODIS FLH product and in situ water quality parameters will enhance our understanding of the accuracy MODIS fs global FLH algorithm and assist in optimizing its calibration for use in monitoring the quality of estuarine and coastal waters worldwide.
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Suleimani, E.; Nicolsky, D.J.; Haeussler, Peter J.; Hansen, R.
2011-01-01
We apply a recently developed and validated numerical model of tsunami propagation and runup to study the inundation of Resurrection Bay and the town of Seward by the 1964 Alaska tsunami. Seward was hit by both tectonic and landslide-generated tsunami waves during the Mw 9.2 1964 mega thrust earthquake. The earthquake triggered a series of submarine mass failures around the fjord, which resulted in land sliding of part of the coastline into the water, along with the loss of the port facilities. These submarine mass failures generated local waves in the bay within 5 min of the beginning of strong ground motion. Recent studies estimate the total volume of underwater slide material that moved in Resurrection Bay to be about 211 million m3 (Haeussler et al. in Submarine mass movements and their consequences, pp 269-278, 2007). The first tectonic tsunami wave arrived in Resurrection Bay about 30 min after the main shock and was about the same height as the local landslide-generated waves. Our previous numerical study, which focused only on the local land slide generated waves in Resurrection Bay, demonstrated that they were produced by a number of different slope failures, and estimated relative contributions of different submarine slide complexes into tsunami amplitudes (Suleimani et al. in Pure Appl Geophys 166:131-152, 2009). This work extends the previous study by calculating tsunami inundation in Resurrection Bay caused by the combined impact of landslide-generated waves and the tectonic tsunami, and comparing the composite inundation area with observations. To simulate landslide tsunami runup in Seward, we use a viscous slide model of Jiang and LeBlond (J Phys Oceanogr 24(3):559-572, 1994) coupled with nonlinear shallow water equations. The input data set includes a high resolution multibeam bathymetry and LIDAR topography grid of Resurrection Bay, and an initial thickness of slide material based on pre- and post-earthquake bathymetry difference maps. For simulation of tectonic tsunami runup, we derive the 1964 coseismic deformations from detailed slip distribution in the rupture area, and use them as an initial condition for propagation of the tectonic tsunami. The numerical model employs nonlinear shallow water equations formulated for depth-averaged water fluxes, and calculates a temporal position of the shoreline using a free-surface moving boundary algorithm. We find that the calculated tsunami runup in Seward caused first by local submarine landslide-generated waves, and later by a tectonic tsunami, is in good agreement with observations of the inundation zone. The analysis of inundation caused by two different tsunami sources improves our understanding of their relative contributions, and supports tsunami risk mitigation in south-central Alaska. The record of the 1964 earthquake, tsunami, and submarine landslides, combined with the high-resolution topography and bathymetry of Resurrection Bay make it an ideal location for studying tectonic tsunamis in coastal regions susceptible to underwater landslides. ?? 2010 Springer Basel AG.
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NASA Astrophysics Data System (ADS)
Shulga, Natalia; Lobys, Nikolay; Drozdova, Anastasia; Peresypkin, Valery
2014-05-01
The present study was carried out in Nha Trang Bay (Southern Vietnam, the South China Sea). The samples of water, suspended matter and bottom sediments were collected in summer 2010-2012 in section from the estuary of the Khai River to the marine part of the bay. The samples were analyzed in the stationary lab of IO RAS, Moscow, by TOC-V-CPH, GC/MS and pirolysis methods. We report here the novel data on sources, transformation and burial of OM coming from the Khai river waters. The investigation is focused on ontent and distribution of suspended matter (SM) in the estuary, dissolved organic carbon (DOC), particulated organic carbon (POC); molecular and group composition of hydrocarbons (n-alkanes, steranes, hopanes) and mercury content in water, SM and bottom sediments. It was found that concentration of POC and SM decrease in the Nha Trang Bay waters from estuary to the open part of the bay. However, major changes in the concentration of SM and POC belong to the zone of salinity gradient.DOC behavior is more stable throughout the study area. Organic-geochemical indicators estimation allowed recognition of genesis and transformation degree of organic matter in the study area. The estuary is characterized by mixed genesis of SM with a predominance of allochthonous organic matter whereas outlying parts of the Nha Trang bay are characterized by autochthonous OM. Composition of OM in sediments reflects regularities identified above, despite of the interannual and seasonal variability in the study area. The investigation reveals a predominance of terrestrial organic matter in the silt sediments of the estuary, transported by the Khai river. Distribution of OM in sediments of marine part of the bay is mosaic, with a predominance of planktonogenic, bacterial or terrestrial input at their complex combination. Local anthropogenic pollution as well as an impact of industrial city effluents are found in river- and seaport areas. According to obtained data sedimentation rate in Nha Trang bay area is 36-118 g/m^2/day in summer season. Sedimentary TOC (%) in samples varies in the range 0.50 - 1.95 in 2010, 0.22 - 1.84 in 2011 and 0.27 - 1.94 in 2012. This variations associated with differences in grain size distribution of sediments and intensity of anthropogenic influence. Mercury (Hg) concentration in the bottom sediments of aquatic systems varies from 2 to 108 ng/g of dry weight. Low concentration of the metal is typical for sediments, where OM is mainly represented by remains of aquatic organisms, while high concentration are common for river- and seaport areas with mainly terrestrial origin. Our study shows terrigenous organic matter is an important agent in the transfer of mercury from land to water ecosystems and Hg migrates in dissolved forms mainly. The reported study was supported by RFBR, research project No:14-05-31059-mol_a.
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NASA Astrophysics Data System (ADS)
Fischer, A.; Ryan, J. P.; Moreno-Madriñán, M. J.
2012-12-01
Recent advances in satellite and airborne remote sensing, such as improvements in sensor and algorithm calibrations and atmospheric correction procedures have provided for increased coverage of remote-sensing, ocean color products for coastal regions. In particular, for the Moderate Resolution Imaging Spectrometer (MODIS), calibration updates, improved aerosol retrievals, and new aerosol models have led to improved atmospheric correction algorithms for turbid waters and have improved the retrieval of ocean-color. This has opened the way for studying coastal ocean phenomena and processes at finer spatial scales. Human population growth and changes in coastal management practices have brought about significant changes in the concentrations of organic and inorganic, particulate and dissolved substances entering the coastal ocean. There is increasing concern that these inputs have led to declines in water quality and increases in local concentrations of phytoplankton, which could result in harmful algal blooms. In two case studies we present improved and validated MODIS coastal observations of fluorescence line height (FLH) to: (1) assess trends in water quality for Tampa Bay, Florida; and (2) illustrate seasonal and annual variability of algal bloom activity in Monterey Bay, California, as well as document estuarine/riverine plume induced red tide events. In a comprehensive analysis of long term (2003-2011) in situ monitoring data and imagery from Tampa Bay, we assess the validity of the MODIS FLH product against chlorophyll-a and a suite of water quality parameters taken in a variety of conditions throughout this large, optically complex estuarine system. A systematic analysis of sampling sites throughout the bay illustrates that the correlations between FLH and in situ chlorophyll-a are influenced by water quality parameters of total nitrogen, total phosphorous, turbidity and biological oxygen demand. Sites that correlated well with satellite imagery were in depths greater than seven meters and were located over five kilometers from shore. Satellite FLH estimates show improving water quality from 2003-2007 with a slight decline up through 2011. Dinoflagellate blooms in Monterey Bay, California have recently increased in frequency and intensity. Nine years of MODIS FLH observations are used to describe the annual and seasonal variability of bloom activity within the Bay. Three classes of MODIS algorithms were correlated against in situ chlorophyll measurements. The FLH algorithm provided the most robust estimate of bloom activity. Elevated concentrations of phytoplankton were evident during the months of August-November, a period during which increased occurrences of dinoflagellate blooms have been observed in situ. Seasonal patterns of FLH show the on- and offshore movement of areas of high phytoplankton biomass between oceanographic seasons. Higher concentrations of phytoplankton are also evident in the vicinity of the land-based nutrient sources and outflows, and cyclonic bay-wide circulation transports these nutrients to a northern Bay bloom incubation region. Both of these case studies illustrate the utility of improved MODIS FLH observations in supporting management decisions in coastal and estuarine waters.
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Earth observations taken during STS-41D mission.
2009-06-25
41D-41-062 (30 Aug-5 Sept 1984) --- An example of the surface details on the Earth seen by orbiting astronauts is provided by this Hasselblad 500 EL/M photograph made with a 250mm lens over Brisbane, Australia. Urban areas and the airport complex lie along the Brisbane River which empties into Moreton Bay. The photograph was shown during the STS-41D postflight press conference held on September 12, 1984.
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Code of Federal Regulations, 2011 CFR
2011-07-01
... Bridge and the San Francisco-Oakland Bay Bridge, San Francisco Bay, California. 165.1187 Section 165.1187... Limited Access Areas Eleventh Coast Guard District § 165.1187 Security Zones; Golden Gate Bridge and the San Francisco-Oakland Bay Bridge, San Francisco Bay, California. (a) Location. All waters extending...
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33 CFR 80.1114 - San Pedro Bay-Anaheim Bay, CA.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false San Pedro Bay-Anaheim Bay, CA. 80... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1114 San Pedro Bay—Anaheim Bay, CA. (a) A line drawn across the seaward extremities of the Anaheim Bay Entrance Jetties; thence to Long...
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33 CFR 80.1114 - San Pedro Bay-Anaheim Bay, CA.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false San Pedro Bay-Anaheim Bay, CA. 80... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1114 San Pedro Bay—Anaheim Bay, CA. (a) A line drawn across the seaward extremities of the Anaheim Bay Entrance Jetties; thence to Long...
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33 CFR 80.1114 - San Pedro Bay-Anaheim Bay, CA.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false San Pedro Bay-Anaheim Bay, CA. 80... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1114 San Pedro Bay—Anaheim Bay, CA. (a) A line drawn across the seaward extremities of the Anaheim Bay Entrance Jetties; thence to Long...
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33 CFR 80.1114 - San Pedro Bay-Anaheim Bay, CA.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false San Pedro Bay-Anaheim Bay, CA. 80... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1114 San Pedro Bay—Anaheim Bay, CA. (a) A line drawn across the seaward extremities of the Anaheim Bay Entrance Jetties; thence to Long...
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33 CFR 80.1114 - San Pedro Bay-Anaheim Bay, CA.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false San Pedro Bay-Anaheim Bay, CA. 80... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1114 San Pedro Bay—Anaheim Bay, CA. (a) A line drawn across the seaward extremities of the Anaheim Bay Entrance Jetties; thence to Long...
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75 FR 36292 - Safety Zone; Bay Swim III, Presque Isle Bay, Erie, PA
Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-25
... of Presque Isle Bay, Lake Erie, near Erie, Pennsylvania between 9 a.m. to 11 a.m. on June 26, 2010.... The safety zone will encompass specified waters of Presque Isle Bay, Erie, Pennsylvania starting at...-AA00 Safety Zone; Bay Swim III, Presque Isle Bay, Erie, PA AGENCY: Coast Guard, DHS. ACTION: Temporary...
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Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false In the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Precautionary areas. 167.101 Section 167.101 Navigation and Navigable... the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Precautionary areas. (a) A precautionary...
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Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false In the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Precautionary areas. 167.101 Section 167.101 Navigation and Navigable... the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Precautionary areas. (a) A precautionary...
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Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false In the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Precautionary areas. 167.101 Section 167.101 Navigation and Navigable... the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Precautionary areas. (a) A precautionary...
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Code of Federal Regulations, 2012 CFR
2012-07-01
... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false In the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Precautionary areas. 167.101 Section 167.101 Navigation and Navigable... the approaches to Narragansett Bay, RI, and Buzzards Bay, MA: Precautionary areas. (a) A precautionary...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-28
... 1625-AA00 Safety Zone; Alexandria Bay Chamber of Commerce, St. Lawrence River, Alexandria Bay, NY... temporary safety zone on the St. Lawrence River, Alexandria Bay, New York. This safety zone is intended to restrict vessels from a portion of the St. Lawrence River during the Alexandria Bay Chamber of Commerce...
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78 FR 30765 - Safety Zone; Bay Village Independence Day Fireworks, Lake Erie, Bay Village, OH
Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-23
...-AA00 Safety Zone; Bay Village Independence Day Fireworks, Lake Erie, Bay Village, OH AGENCY: Coast... zone on Lake Erie, Bay Village, OH. This safety zone is intended to restrict vessels from a portion of Lake Erie during the Bay Village Independence Day Fireworks display. This temporary safety zone is...
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77 FR 39420 - Safety Zone; Bay Village Independence Day Fireworks, Lake Erie, Bay Village, OH
Federal Register 2010, 2011, 2012, 2013, 2014
2012-07-03
...-AA00 Safety Zone; Bay Village Independence Day Fireworks, Lake Erie, Bay Village, OH AGENCY: Coast... zone on Lake Erie, Bay Village, OH. This safety zone is intended to restrict vessels from a portion of Lake Erie during the Bay Village Independence Day Fireworks display. This temporary safety zone is...
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33 CFR 100.911 - Bay City Airshow, Bay City, MI.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Bay City Airshow, Bay City, MI. 100.911 Section 100.911 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.911 Bay City Airshow, Bay City, MI. (a...
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33 CFR 100.911 - Bay City Airshow, Bay City, MI.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Bay City Airshow, Bay City, MI. 100.911 Section 100.911 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.911 Bay City Airshow, Bay City, MI. (a...
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33 CFR 100.911 - Bay City Airshow, Bay City, MI.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Bay City Airshow, Bay City, MI. 100.911 Section 100.911 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.911 Bay City Airshow, Bay City, MI. (a...
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33 CFR 100.919 - International Bay City River Roar, Bay City, MI.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false International Bay City River Roar, Bay City, MI. 100.919 Section 100.919 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Bay City River Roar, Bay City, MI. (a) Regulated Area. A regulated area is established to include all...
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33 CFR 100.919 - International Bay City River Roar, Bay City, MI.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false International Bay City River Roar, Bay City, MI. 100.919 Section 100.919 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Bay City River Roar, Bay City, MI. (a) Regulated Area. A regulated area is established to include all...
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33 CFR 100.911 - Bay City Airshow, Bay City, MI.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Bay City Airshow, Bay City, MI. 100.911 Section 100.911 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.911 Bay City Airshow, Bay City, MI. (a...
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33 CFR 100.911 - Bay City Airshow, Bay City, MI.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bay City Airshow, Bay City, MI. 100.911 Section 100.911 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.911 Bay City Airshow, Bay City, MI. (a...
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78 FR 38580 - Special Local Regulation; Tall Ships Celebration Bay City, Bay City, MI
Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-27
...-AA08 Special Local Regulation; Tall Ships Celebration Bay City, Bay City, MI AGENCY: Coast Guard, DHS... regulatory act for the celebration specific to Bay City, MI, the Coast Guard recently published a separate... various events throughout the Great Lakes this summer, to include the Tall Ships Celebration Bay City...
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Code of Federal Regulations, 2010 CFR
2010-07-01
... Bridge and the San Francisco-Oakland Bay Bridge, San Francisco Bay, California. 165.1187 Section 165.1187... Limited Access Areas Eleventh Coast Guard District § 165.1187 Security Zones; Golden Gate Bridge and the San Francisco-Oakland Bay Bridge, San Francisco Bay, California. (a) Location. All waters extending...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-23
...-AA00 Safety Zone: Bay Bridge Load Transfer Safety Zone, San Francisco Bay, San Francisco, CA AGENCY... the Bay Bridge Load Transfer Safety Zone from August 1, 2012 through October 31, 2012. This safety... Bay Bridge from the temporary suspension arrangement to the permanent suspension arrangement, the...
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NASA Astrophysics Data System (ADS)
Clemens, J. D.; Stevens, G.; Frei, D.; Joseph, C. S. A.
2017-12-01
The Saldanha eruption centre, on the West Coast of South Africa, consists of 542 Ma, intracaldera, S-type, rhyolite ignimbrites divided into the basal Saldanha Ignimbrite and the partly overlying Jacob's Bay Ignimbrite. Depleted-mantle Nd model ages suggest magma sources younger than the Early Mesoproterozoic, and located within the Neoproterozoic Malmesbury Group and Swartland complex metasedimentary and metavolcanic rocks that form the regional basement. The Sr isotope systematics suggest that the dominant source rocks were metavolcaniclastic rocks and metagreywackes, and that the magmas formed from separate batches extracted from the same heterogeneous source. No apparent magma mixing trends relate the Saldanha to the Jacob's Bay Ignimbrites, or either of these to the magmas that formed the Plankiesbaai or Tsaarsbank Ignimbrites in the neighbouring Postberg eruption centre. The magmas were extracted from their source rocks carrying small but significant proportions of peritectic and restitic accessory minerals. Variations in the content of this entrained crystal cargo were responsible for most of the chemical variations in the magmas. Although we cannot construct a cogent crystal fractionation model to relate these groups of magmas, at least some crystal fractionation occurred, as an overlay on the primary signal due to peritectic assemblage entrainment (PAE). Thus, the causes of the cryptic chemical variation among the ignimbrite magmas of the Saldanha centre are variable, but dominated by the compositions of the parent melts and PAE. The preservation of clear, source-inherited chemical signatures, in individual samples, calls into question the common interpretation of silicic calderas as having been formed in large magma reservoirs, with magma compositions shaped by magma mingling, mixing, and fractional crystallization. The Saldanha rocks suggest a more intimate connection between source and erupted magma, and perhaps indicate that silicic magmas are too viscous to be significantly modified by magma-chamber processes.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Valiela, I.; Foreman, K.; LaMontagne, M.
1992-12-01
Human activities on coastal watersheds provide the major sources of nutrients entering shallow coastal ecosystems. Nutrient loadings from watersheds alter structure and function of receiving aquatic ecosystems. To investigate this coupling of land to marine systems, a series of subwatersheds of Waquoit Bay differing in degree of urbanization and with widely different nutrient loading rates was studied. The subwatersheds differ in septic tanks numbers and forest acreage. Ground water is the major mechanism that transports nutrients to coastal waters. Some attenuation of nutrient concentrations within the aquifer or at the sediment-water interface, but significant increases in the nutrient content ofmore » groundwater arriving at the shore's edge are in urbanized areas. The groundwater flows through the sediment-water boundary, and sufficient groundwater-borne nutrients (nitrogen in particular) traverse the sediment-water boundary to cause significant changes in the aquatic ecosystem. These loading-dependent alterations include increased nutrients in water, greater primary production by phytoplankton, and increased macroalgal biomass and growth. The increased macroalgal biomass dominates the bay ecosystem through second- or third-order effects such as alterations of nutrient status of water columns and increasing frequency of anoxic events. The increases in seaweeds have decreased the areas covered by eelgrass habitats. The change in habitat type, plus the increased frequency of anoxic events, change the composition of the benthic fauna. The importance of bottom-up control in shallow coastal food webs is evident. The coupling of land to sea by groundwater-borne nutrient transport is mediated by a complex series of steps, making it unlikely to find a one-to-one relation between land use and conditions in the aquatic ecosystem. Appropriate models may provide a way to deal with the complexities of the coupling. 22 refs., 14 figs., 5 tabs.« less
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75 FR 11837 - Chesapeake Bay Watershed Initiative
Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-12
... DEPARTMENT OF AGRICULTURE Commodity Credit Corporation Chesapeake Bay Watershed Initiative AGENCY...: Notice of availability of program funds for the Chesapeake Bay Watershed Initiative. SUMMARY: The... through the Chesapeake Bay Watershed Initiative for agricultural producers in the Chesapeake Bay watershed...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-19
... Lands, as an Addition to the Bay Mills Indian Reservation for the Bay Mills Indian Community of Michigan... acres, more or less, to be added to the Bay Mills Indian Reservation for the Bay Mills Indian Community... the land described below. The land was proclaimed to be an addition to the Bay Mills Indian...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-09-05
... an Addition to the Bay Mills Indian Reservation for the Bay Mills Indian Community of Michigan AGENCY..., more or less, to be added to the Bay Mills Indian Reservation for the Bay Mills Indian Community of... the land described below. The land was proclaimed to be an addition to the Bay Mills Indian...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-13
... Acquisition, as an Addition to the Bay Mills Indian Reservation for the Bay Mills Indian Community of Michigan..., more or less, to be added to the Bay Mills Indian Reservation for the Bay Mills Indian Community of... the land described below. The land was proclaimed to be an addition to the Bay Mills Indian...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-02-18
..., as an Addition to the Bay Mills Indian Reservation for the Bay Mills Indian Community of Michigan..., more or less, to be added to the Bay Mills Indian Reservation for the Bay Mills Indian Community of... the land described below. The land was proclaimed to be an addition to the Bay Mills Indian...
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Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 1 2013-10-01 2013-10-01 false Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island Sound and easterly entrance to Long Island Sound, NY. 7.20 Section 7.20... Atlantic Coast § 7.20 Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island...
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Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 1 2011-10-01 2011-10-01 false Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island Sound and easterly entrance to Long Island Sound, NY. 7.20 Section 7.20... Atlantic Coast § 7.20 Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island...
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Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 1 2014-10-01 2014-10-01 false Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island Sound and easterly entrance to Long Island Sound, NY. 7.20 Section 7.20... Atlantic Coast § 7.20 Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island...
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Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 1 2012-10-01 2012-10-01 false Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island Sound and easterly entrance to Long Island Sound, NY. 7.20 Section 7.20... Atlantic Coast § 7.20 Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island...
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Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 1 2010-10-01 2010-10-01 false Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island Sound and easterly entrance to Long Island Sound, NY. 7.20 Section 7.20... Atlantic Coast § 7.20 Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island...
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33 CFR 162.125 - Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Sturgeon Bay and the Sturgeon Bay Ship Canal, Wisc. 162.125 Section 162.125 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.125 Sturgeon Bay and the Sturgeon Bay Ship...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-10-15
... Safety Zone, Oyster Festival 30th Anniversary Fireworks Display, Oyster Bay; Oyster Bay, NY AGENCY: Coast... zone on the navigable waters of Oyster Bay near Oyster Bay, NY for the Oyster Festival 30th Anniversary... Oyster Festival 30th Anniversary Fireworks Display is scheduled for October 19, 2013 and is one of...
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33 CFR 334.762 - Naval Support Activity Panama City; North Bay and West Bay; restricted areas.
Code of Federal Regulations, 2011 CFR
2011-07-01
... City; North Bay and West Bay; restricted areas. 334.762 Section 334.762 Navigation and Navigable Waters... REGULATIONS § 334.762 Naval Support Activity Panama City; North Bay and West Bay; restricted areas. (a) The..., Naval Support Activity, Panama City Florida, and such agencies as he/she may designate. [73 FR 52927...
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33 CFR 334.762 - Naval Support Activity Panama City; North Bay and West Bay; restricted areas.
Code of Federal Regulations, 2010 CFR
2010-07-01
... City; North Bay and West Bay; restricted areas. 334.762 Section 334.762 Navigation and Navigable Waters... REGULATIONS § 334.762 Naval Support Activity Panama City; North Bay and West Bay; restricted areas. (a) The..., Naval Support Activity, Panama City Florida, and such agencies as he/she may designate. [73 FR 52927...
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10. VIEW TO NORTHEAST FROM WITHIN SOUTHWEST BAY, LOOKING THROUGH ...
10. VIEW TO NORTHEAST FROM WITHIN SOUTHWEST BAY, LOOKING THROUGH CENTER BAY AND INTO NORTHEAST BAY. NOTE TRAVELING BRIDGE CRANE OVERHEAD AND SWINGING BOOM CRANES ATTACHED TO COLUMNS ON RIGHT AND LEFT. NOTE ALSO THE DIFFERENCE IN TRUSSES SUPPORTING CRANEWAY TRACKS FOR SIDE BAYS AND CENTER BAY. TRUSSES SUPPORTING CRANEWAY TRACKS IN SIDE BAYS (CENTER FOREGROUND AND FAR BACKGROUND) ARE HOWE TRUSSES WITH WOOD DIAGONALS AND STEEL VERTICALS. TRUSSES SUPPORTING CRANEWAY TRACKS IN CENTER BAY (MID BACKGROUND) ARE PRATT TRUSSES WITH WOOD VERTICALS AND DIAGONALS. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA
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Mbonde, Athanasio S.; Sitoki, Lewis; Kurmayer, Rainer
2017-01-01
This study was carried out in order to investigate the spatial variation of algal toxin (microcystin) concentrations along the shoreline of Lake Victoria. A total of 16 nearshore stations differing in connectivity to the main lake basin were categorized as either closed bays (ratio of bay area to bay opening < 1) or open bays (ratio ≥ 1) and sampled during November and December 2009. Water samples were analyzed for total phosphorus (TP), chlorophyll a, phytoplankton community composition and concentrations of microcystin (MC). Open and closed bays were significantly different for phytoplankton abundance and composition: Average phytoplankton biovolume was higher for closed bays (45 mm3 L-1 ± 11 SE) than open bays (5 ± 2 mm3 L-1). Cyanobacterial biovolume (mainly Microcystis spp., Anabaena spp. and Planktolyngbya spp.) also was significantly higher in closed bays (82 ± 9% of total biovolume) than in open bays (44 ± 5%). In contrast, diatom biovolume was lower in closed bays (7 ± 1%) than in open bays (36 ± 6%). MCs were found only among sites from closed bays and concentrations ranged from 0.4 to 13 μg L-1 MC-LR equiv. and coincided with high abundance of Microcystis spp. It is concluded that the level of water exchange from individual bays to the main basin is an important factor influencing eutrophication and microcystin production in nearshore habitats of Lake Victoria. PMID:28077928
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-13
..., as an Addition to the Bay Mills Indian Reservation for the Bay Mills Indian Community of Michigan..., more or less, to be added to the Bay Mills Indian Reservation for the Bay Mills Indian Community of... Mills Indian Reservation and part of the Bay Mills Indian Community of Michigan for the exclusive use of...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-13
... Acquisition, as an Addition to the Bay Mills Indian Reservation for the Bay Mills Indian Community of Michigan..., more or less, to be added to the Bay Mills Indian Reservation for the Bay Mills Indian Community of... the land described below. The land was proclaimed to be an addition to the Bay Mills Indian...
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75 FR 17329 - Safety Zone; Big Bay Fourth of July Fireworks, San Diego Bay, San Diego, CA
Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-06
...-AA00 Safety Zone; Big Bay Fourth of July Fireworks, San Diego Bay, San Diego, CA AGENCY: Coast Guard... safety zone on the navigable waters of the San Diego Bay in support of the Big Bay July Fourth Show to Benefit the San Diego Armed Services YMCA. This temporary safety zone is necessary to provide for the...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-31
...-AA09 Drawbridge Operation Regulation; Port of Coos Bay Railroad Bridge, Coos Bay, North Bend, OR AGENCY... regulation for the Coos Bay Railroad Bridge, Coos Bay, mile 9.0, at North Bend, Oregon to delete the... necessary to make the sound signals used at the bridge consistent with other bridges in the area and to...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-03-05
... Mobile Offshore Drilling Unit (MODU) KULLUK currently located in Kiliuda Bay, Kodiak Island, Alaska with... large ocean-going drill vessel, while it is under tow from Kiliuda Bay, Kodiak Island to Captains Bay...
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Giant sand waves at the mouth of San Francisco Bay
Barnard, P.L.; Hanes, D.M.; Rubin, D.M.; Kvitek, R.G.
2006-01-01
A field of giant sand waves, among the largest in the world, recently was mapped in high resolution for the first time during a multibeam survey in 2004 and 2005 through the strait of the Golden Gate at the mouth of San Francisco Bay in California (Figure la). This massive bed form field covers an area of approximately four square kilometers in water depths ranging from 30 to 106 meters, featuring more than 40 distinct sand waves with crests aligned approximately perpendicular to the dominant tidally generated cross-shore currents, with wavelengths and heights that measure up to 220 meters and 10 meters, respectively. Sand wave crests can be traced continuously for up to two kilometers across the mouth of this energetic tidal inlet, where depth-averaged tidal currents through the strait below the Golden Gate Bridge exceed 2.5 meters per second during peak ebb flows. Repeated surveys demonstrated that the sand waves are active and dynamic features that move in response to tidally generated currents. The complex temporal and spatial variations in wave and tidal current interactions in this region result in an astoundingly diverse array of bed form morphologies, scales, and orientations. Bed forms of approximately half the scale of those reported in this article previously were mapped inside San Francisco Bay during a multibeam survey in 1997 [Chin et al., 1997].
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Assessment of the Spatial Distribution of Metal(Oid)s in Soils Around an Abandoned Pb-Smelter Plant
NASA Astrophysics Data System (ADS)
dos Santos, Nielson Machado; do Nascimento, Clístenes Williams Araújo; Matschullat, Jörg; de Olinda, Ricardo Alves
2017-03-01
Todos os Santos (All Saints) Bay area, NE-Brazil, is known for one of the most important cases of urban lead (Pb) contamination in the world. The main objective of this work was to assess and interpret the spatial distribution of As, Cd, Hg, Pb, and Zn in "background" soils of this environmentally impacted bay area, using a combination of geostatistical and multivariate analytical methods to distinguish between natural and anthropogenic sources of those metal(oid)s in soils. We collected 114 topsoil samples (0.0-0.2 m depth) from 38 sites. The median values for trace metal concentrations in soils (mg kg-1) followed the order Pb (33.9) > Zn (8.8) > As (1.2) > Cd (0.2) > Hg (0.07), clearly reflecting a Pb-contamination issue. Principal component analysis linked Cd, Pb, and Zn to the same factor (F1), chiefly corroborating their anthropogenic origin; yet, both Pb and Zn are also influenced by natural lithogenic sources. Arsenic and Hg concentrations (F2) are likely related to the natural component alone; their parent material (igneous-metamorphic rocks) seemingly confirm this hypothesis. The heterogeneity of sources and the complexity of the spatial distribution of metals in large areas such as the Todos os Santos Bay warrant, the importance of multivariate and geostatistical analyses in the interpretation of environmental data.
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Interaction of lateral baroclinic forcing and turbulence in an estuary
Lacy, J.R.; Stacey, M.T.; Burau, J.R.; Monismith, Stephen G.
2003-01-01
Observations of density and velocity in a channel in northern San Francisco Bay show that the onset of vertical density stratification during flood tides is controlled by the balance between the cross-channel baroclinic pressure gradient and vertical mixing due to turbulence. Profiles of velocity, salinity, temperature, and suspended sediment concentration were measured in transects across Suisun Cutoff, in northern San Francisco Bay, on two days over the 12.5-hour tidal cycle. During flood tides an axial density front developed between fresher water flowing from the shallows of Grizzly Bay into the northern side of Suisun Cutoff and saltier water flowing up the channel. North of the front, transverse currents were driven by the lateral salinity gradient, with a top-to-bottom velocity difference greater than 30 cm/s. South of the front, the secondary circulation was weak, and along-channel velocities were greater than to the north. The gradient Richardson number shows that stratification was stable north of the front, while the water column was turbulently mixed south of the front. Time-series measurements of velocity and salinity demonstrate that the front develops during each tidal cycle. In estuaries, longitudinal dynamics predict less stratification during flood than ebb tides. These data show that stratification can develop during flood tides due to a lateral baroclinic pressure gradient in estuaries with complex bathymetry.
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An integrated approach for identifying priority contaminant in ...
Environmental assessment of complex mixtures typically requires integration of chemical and biological measurements. This study demonstrates the use of a combination of instrumental chemical analyses, effects-based monitoring, and bio-effects prediction approaches to help identify potential hazards and priority contaminants in two Great Lakes Areas of Concern (AOCs), the Lower Green Bay/Fox River located near Green Bay, WI, USA and the Milwaukee River Estuary, located near Milwaukee, WI, USA. Fathead minnows were caged at four sites within each AOC (eight sites total). Following 4 d of in situ exposure, tissues and biofluids were sampled and used for targeted biological effects analyses. Additionally, 4 d composite water samples were collected concurrently at each caged fish site and analyzed for 134 analytes as well as evaluated for total estrogenic and androgenic activity using cell-based bioassays. Of the analytes examined, 75 were detected in composite samples from at least one site. Based on multiple analyses, one site in the East River and another site near a paper mill discharge from lower Green Bay/Fox River AOC, were prioritized due to their estrogenic and androgenic acitvity, respectively. The water samples from other sites generally did not exhibit significant estrogenic or androgenic activity, nor was there evidence for endocrine disruption in the fish exposed at these sites as indicated the the lack of alterations in ex vivo steroid production, c
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Predicting potentially toxigenic Pseudo-nitzschia blooms in the Chesapeake Bay
Anderson, C.R.; Sapiano, M.R.P.; Prasad, M.B.K.; Long, W.; Tango, P.J.; Brown, C.W.; Murtugudde, R.
2010-01-01
Harmful algal blooms are now recognized as a significant threat to the Chesapeake Bay as they can severely compromise the economic viability of important recreational and commercial fisheries in the largest estuary of the United States. This study describes the development of empirical models for the potentially domoic acid-producing Pseudo-nitzschia species complex present in the Bay, developed from a 22-year time series of cell abundance and concurrent measurements of hydrographic and chemical properties. Using a logistic Generalized Linear Model (GLM) approach, model parameters and performance were compared over a range of Pseudo-nitzschia bloom thresholds relevant to toxin production by different species. Small-threshold blooms (???10cellsmL-1) are explained by time of year, location, and variability in surface values of phosphate, temperature, nitrate plus nitrite, and freshwater discharge. Medium- (100cellsmL-1) to large- threshold (1000cellsmL-1) blooms are further explained by salinity, silicic acid, dissolved organic carbon, and light attenuation (Secchi) depth. These predictors are similar to other models for Pseudo-nitzschia blooms on the west coast, suggesting commonalities across ecosystems. Hindcasts of bloom probabilities at a 19% bloom prediction point yield a Heidke Skill Score of -53%, a Probability of Detection ~75%, a False Alarm Ratio of ~52%, and a Probability of False Detection ~9%. The implication of possible future changes in Baywide nutrient stoichiometry on Pseudo-nitzschia blooms is discussed. ?? 2010 Elsevier B.V.
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Jung, Hun Bok; Charette, Matthew A.; Zheng, Yan
2009-01-01
A field, laboratory, and modeling study of As in groundwater discharging to Waquoit Bay, MA, shed light on coupled control of chemistry and hydrology on reactive transport of As in a coastal aquifer. Dissolved Fe(II) and As(III) in a reducing groundwater plume bracketed by an upper and a lower redox interface are oxidized as water flows towards the bay. This results in precipitation of Fe(III) oxides, along with oxidation and adsorption of As to sediment at the redox interfaces where concentrations of sedimentary HCl-leachable Fe (80~90% Fe(III)) are 734±232 mg kg-1, sedimentary phosphate extractable As (90~100% As(V)) are 316±111 μg kg-1, and are linearly correlated. Batch adsorption of As(III) onto orange, brown and gray sediments follows Langmuir isotherms, and can be fitted by a surface complexation model (SCM) assuming a diffuse layer for ferrihydrite. The sorption capacity and distribution coefficient for As increase with decreasing sediment Fe(II)/Fe. To allow accumulation of the amount of sediment As, similar hydrogeochemical conditions would have been operating for thousands of years at Waquoit Bay. The SCM simulated the observed dissolved As concentration better than a parametric approach based on Kd. Site specific isotherms should be established for Kd or SCM based models. PMID:19708362
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NASA Astrophysics Data System (ADS)
De Troch, Marleen; Gurdebeke, Shirley; Fiers, Frank; Vincx, Magda
2001-02-01
This study deals with the relation between tropical meiofauna and environmental variables by comparing the 'benthic' (i.e. in the bare sediment adjacent to seagrass plants) and the 'epiphytic' (i.e. in samples including seagrass plants) meiofauna associated with five seagrass species from the high intertidal to the high subtidal zone in Gazi Bay (Kenya). Ordination and variance analysis revealed three distinct 'benthic' and two 'epiphytic' meiofauna assemblages. These assemblages corresponded entirely with those identified for the seagrass species: a high intertidal pioneer association ( Halophila ovalis/ Halodule wrightii), an intertidal climax assemblage ( Thalassia hemprichii) and a high subtidal pioneer association ( Halophila stipulacea/ Syringodium isoetifolium). These data support the hypothesis that meiofaunal communities correspond to the characteristic zonation of the seagrass vegetation in Gazi Bay. In beds of the pioneer seagrass species, the close relationship between sediment characteristics and both 'benthic' and 'epiphytic' meiofauna communities suggests that these pioneer communities were mainly driven by physical factors. The 'benthic' communities adjacent to the climax seagrass species T. hemprichii were more structured by biogenic factors, e.g. % TOM, chlorophyll a and c, fucoxanthin, habitat complexity and growth form of the seagrass species. For its associated 'epiphytic' meiofauna the latter conclusion was even more striking. These data corroborate the importance of physical factors in disturbed environments (intertidal zone, near pioneer seagrasses) and of biotic factors in more stable conditions (subtidal zone, near climax seagrasses).
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Wong, Florence L.; Woodrow, Donald L.; McGann, Mary
2013-01-01
Heavy or high-specific gravity minerals make up a small but diagnostic component of sediment that is well suited for determining the provenance and distribution of sediment transported through estuarine and coastal systems worldwide. By this means, we see that surficial sand-sized sediment in the San Francisco Bay Coastal System comes primarily from the Sierra Nevada and associated terranes by way of the Sacramento and San Joaquin Rivers and is transported with little dilution through the San Francisco Bay and out the Golden Gate. Heavy minerals document a slight change from the strictly Sierran-Sacramento mineralogy at the confluence of the two rivers to a composition that includes minor amounts of chert and other Franciscan Complex components west of Carquinez Strait. Between Carquinez Strait and the San Francisco Bar, Sierran sediment is intermingled with Franciscan-modified Sierran sediment. The latter continues out the Gate and turns southward towards beaches of the San Francisco Peninsula. The Sierran sediment also fans out from the San Francisco Bar to merge with a Sierran province on the shelf in the Gulf of the Farallones. Beach-sand sized sediment from the Russian River is transported southward to Point Reyes where it spreads out to define a Franciscan sediment province on the shelf, but does not continue southward to contribute to the sediment in the Golden Gate area.
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A Coastal Bay Summer Breeze Study, Part 1: Results of the Quiberon 2006 Experimental Campaign
NASA Astrophysics Data System (ADS)
Mestayer, Patrice G.; Calmet, Isabelle; Herlédant, Olivier; Barré, Sophie; Piquet, Thibaud; Rosant, Jean-Michel
2018-04-01
The Quiberon 2006 experiment was launched to document the onset and development of land and sea breezes over a semi-circular coastal bay propitious to inshore sailing competitions. The measurements were taken during the 2 weeks of 16-28 June 2006. Micrometeorological variables were recorded at three shore sites around the bay using turbulence sensors on 10-30-m high masts, on four instrumented catamarans at selected sites within the bay, and at a fourth shore site with a Sodar. Synoptic data and local measurements are analyzed here from the point of view of both micrometeorologists and competition skippers, testing in particular the empirical rules of breeze veering and backing according to the wind direction with respect to the coastline orientation at the mesoscale (the quadrant theory). Our analysis focuses on the patterns of lower-altitude wind direction and speed around the bay and over the water basin, and the temporal variations during the periods of the breeze onset, establishment and thermal reinforcement. In offshore synoptic-flow conditions (quadrants 1 and 2), the clockwise rotation of the surface flow had a very large amplitude, reaching up to 360°. The breeze strength was negatively correlated to that of the synoptic wind speed. In conditions of onshore synoptic flow from the west (quadrant 3) at an angle to the mainland coast but perpendicular to the Quiberon peninsula, the rotation of the flow was backwards in the early morning and clockwise during the day with a moderate amplitude (40°-50°) around the synoptic wind direction. As the surface wind speed was much larger than the synoptic wind speed, such a case we have designated as a "synoptic breeze". The breeze onset was shown to fail several times under the influence of weak non-thermal events, e.g., the passage of an occluded front or clouds or an excess of convection. Finally, several local-scale influences of the complex coastal shape appeared in our measurements, e.g., wind fanning in the lee of the isthmus and airflow skirting around the peninsula forehand.