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Sample records for rubble mound breakwaters

  1. Effects of vertical wall and tetrapod weights on wave overtopping in rubble mound breakwaters under irregular wave conditions

    NASA Astrophysics Data System (ADS)

    Park, Sang Kil; Dodaran, Asgar Ahadpour; Han, Chong Soo; Shahmirzadi, Mohammad Ebrahim Meshkati

    2014-12-01

    Rubble mound breakwaters protect the coastal line against severe erosion caused by wave action. This study examined the performance of different sizes and properties (i.e. height of vertical wall and tetrapod size) of rubble mound breakwaters on reducing the overtopping discharge. The physical model used in this study was derived based on an actual rubble mound in Busan Yacht Harbor. This research attempts to fill the gap in practical knowledge on the combined effect of the armor roughness and vertical wall on wave overtopping in rubble mound breakwaters. The main governing parameters used in this study were the vertical wall height, variation of the tetrapod weights, initial water level elevation, and the volume of overtopping under constant wave properties. The experimental results showed that the roughness factor differed according to the tetrapod size. Furthermore, the overtopping discharge with no vertical wall was similar to that with relatively short vertical walls ( 1 γv = 1). Therefore, the experimental results highlight the importance of the height of the vertical wall in reducing overtopping discharge. Moreover, a large tetrapod size may allow coastal engineers to choose a shorter vertical wall to save cost, while obtaining better performance.

  2. Ecological effects of rubble-mound breakwater construction and channel dredging at West Harbor, Ohio (western Lake Erie)

    USGS Publications Warehouse

    Manny, Bruce A.; Schloesser, Donald W.; Brown, Charles L.; French, John R. P., III

    1985-01-01

    The investigation reported herein indicated that breakwater construction and associated channel dredging activities by the US Army Corps of Engineers in western Lake Erie at the entrance to West Harbor (Ohio) had no detectable adverse impacts on the distributions or abundances of macrozoobenthos and fishes. Rather, increases were noted in the number of fish eggs and larvae and in the density and biomass of periphyton and macrozoobenthos on and near the breakwaters. The area also served as a nursery ground for 20 species of fishes both during and after construction and dredging activities. Colonization of the breakwaters by periphyton, primarily a green alga (Cladophora glomerata), diatoms (Gomphonema parvulum), and a bluegreen alga (Oscillatoria tenuis), and by macrozoobenthos, primarily worms (Oligochaeta), amphipods (Gammarus spp.), and midge larvae (Chironomidae), was rapid and extensive, indicating that the breakwaters provided new, favorable habitat for primary and secondary producer organisms. Marked adverse changes in water quality, especially reduced dissolved oxygen concentrations (25 mg/l), occurred around the entrance to West Harbor in 1983 following cessation of construction and dredging activities. These water quality changes, however, could not be ascribed with certainty to construction and dredging activities at West Harbor. Construction of additional breakwaters in the study area at that time by the State of Ohio served to confound determination of the responsible causal factors.

  3. Paleoenvironmental reconstruction of a downslope accretion history: From coralgal-coralline sponge rubble to mud mound deposits (Eocene, Ainsa Basin, Spain)

    NASA Astrophysics Data System (ADS)

    Rodríguez-Martínez, Marta; Reitner, Joachim

    2015-12-01

    In the Lutetian intraslope Ainsa sub-basin, small, sub-spherical, carbonate mud mounds occur associated with hemipelagic marls and mixed gravity flow deposits. The studied mud mounds consist of a mixture of allochthonous, parautochthonous and autochthonous components that show evidences of reworking, bioerosion, and accretion by different fossil assemblages at different growth stages. The crusts of microbial-lithistid sponges played an important role stabilizing the rubble of coralgal-coralline sponges and formed low-relief small benthic patches in a dominant marly soft slope environment. These accidental hard substrates turned into suitable initiation/nucleation sites for automicrite production (dense and peloidal automicrites) on which the small mud mounds dominated by opportunistic epi- and infaunal heterozoan assemblages grew. A detailed microfacies mapping and paleoenvironmental analysis reveals a multi-episodic downslope accretion history starred by demosponges (coralline and lithistid sponges), agariciid corals, calcareous red algae, putative microbial benthic communities and diverse sclerobionts from the upper slope to the middle slope. The analyzed mud mound microfacies are compared with similar fossil assemblages and growth fabrics described in many fossil mud mounds, and with recent deep-water fore reefs and cave environments.

  4. Rubble around Jupiter

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    NASA's Jet Propulsion Laboratory has announced that Amalthea, a 270-km-long, potato-shaped inner moon of Jupiter, "apparently is a loosely packed pile of rubble," with empty space where the rubble does not fit well together.This is among the new findings about the moon announced by JPL astronomer John Anderson and his colleagues on 9 December at the AGU Fall Meeting in San Francisco.

  5. Rubble around Jupiter

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    NASA's Jet Propulsion Laboratory has announced that Amalthea, a 270-km-long, potato-shaped inner moon of Jupiter, “apparently is a loosely packed pile of rubble,” with empty space where the rubble does not fit well together.This is among the new findings about the moon announced by JPL astronomer John Anderson and his colleagues on 9 December at the AGU Fall Meeting in San Francisco.

  6. Band of Rubble

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This artist's animation illustrates a massive asteroid belt in orbit around a star the same age and size as our Sun. Evidence for this possible belt was discovered by NASA's Spitzer Space Telescope when it spotted warm dust around the star, presumably from asteroids smashing together.

    The view starts from outside the belt, where planets like the one shown here might possibly reside, then moves into to the dusty belt itself. A collision between two asteroids is depicted near the end of the movie. Collisions like this replenish the dust in the asteroid belt, making it detectable to Spitzer.

    The alien belt circles a faint, nearby star called HD 69830 located 41 light-years away in the constellation Puppis. Compared to our own solar system's asteroid belt, this one is larger and closer to its star - it is 25 times as massive, and lies just inside an orbit equivalent to that of Venus. Our asteroid belt circles between the orbits of Mars and Jupiter.

    Because Jupiter acts as an outer wall to our asteroid belt, shepherding its debris into a series of bands, it is possible that an unseen planet is likewise marshalling this belt's rubble. Previous observations using the radial velocity technique did not locate any large gas giant planets, indicating that any planets present in this system would have to be the size of Saturn or smaller.

    Asteroids are chunks of rock from 'failed' planets, which never managed to coalesce into full-sized planets. Asteroid belts can be thought of as construction sites that accompany the building of rocky planets.

  7. 1. View looking northwest, showing Saybrook west breakwater and Lynde ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. View looking northwest, showing Saybrook west breakwater and Lynde Point Lighthouse in the right background - Saybrook Breakwater Light, South tip of west end of Saybrook Breakwater, Old Saybrook, Middlesex County, CT

  8. Late Mississippian lime mud mounds, Pitkin Formation, northern Arkansas

    SciTech Connect

    Manger, W.L.; Ar, V.P.; Webb, G.E.

    1984-04-01

    Carbonates deposited under shallow, open shelf conditions during the Late Mississippian in northern Arkansas exhibit numerous discrete to coalescing lime mud mounds up to 20 m (65 ft) high and tens of meters in diameter. The mounds are composed of a carbonate mud core, typically with fenestrate texture, entrapped by a loosely organized framework dominated by cystoporate bryozoans and rugose corals in the lower part, and by blue-green algae and cryptostomous bryozoans in the upper part. Disarticulated crinozoan detritus is common throughout the core, suggesting that these organisms also contributed to entrapment of lime mud. During deposition, the mud core was indurated enough to support and preserve vertical burrows. Also, rubble of core mudstone is found on the flanks of some mounds, suggesting some erosion. Intermound lithology is a shoaling-upward sequence dominated by oolitic and bioclastic grainstones and packstones. Shale is also present in minor amounts. The Pitkin mounds, interbedded with these intermound sequences, developed contemporaneously with them. Depositional relief was probably less than 3 m (10 ft). The mounds expanded laterally during periods of quieter water; their growth was impeded during times of higher energy. Contacts of the mound and intermound lithologic characteristics are sharp, truncating surfaces. Mound deposition ended with the onset of high energy conditions throughout the region.

  9. Are some meteoroids rubble piles?

    NASA Astrophysics Data System (ADS)

    Borovička, Jiri

    2015-08-01

    It is generally accepted that some asteroids are rubble piles, i.e. strengthless aggregates of boulders of various sizes held together only by mutual gravity. This is particularly true for asteroids in the size range from ~ 200 m to 10 km, whose rotations are in almost all cases slower that the surface disruption barrier, at which the centrifugal force would exceed the gravitational force. On the other hand, smaller asteroids often rotate rapidly.Recently, Sánchez and Scheeres (2014, Meteorit. Planet. Sci. 49, 788) proposed that rubble piles may have some cohesive strength provided by van der Waals forces between small grains. They estimate the strength to be about 25 Pa. Such a low strength would be sufficient to hold some rapidly rotating small asteroids together against centrifugal force, even if they were rubble piles. In particular, Sánchez and Scheeres (2014) argued that asteroid 2008 TC3 was a rubble pile. That asteroid entered the Earth’s atmosphere and produced meteorites Almahata Sitta.Asteroids and meteoroids entering the atmosphere are subject to dynamic pressure p = ρv2, where ρ is atmospheric density and v is velocity. It can be expected that they break-up when the dynamic pressure exceeds their strength. Fragmentation of meteoroids is indeed common. For asteroidal bodies it usually occurs at pressures 0.1 - 10 MPa (Popova et al. 2011, Meteorit. Planet. Sci. 46, 1525). For example, the main break-up of 2008 TC3 occurred at 0.9 MPa. These pressures are lower than the strength of solid meteoric rocks but dramatically exceed the expected strength for rubble piles. They best correspond to fractured stones. Nevertheless, the first break-up of rubble piles can be expected at heights above 100 km, earlier than the intensive evaporation starts and the fireball begins to be visible. Is it possible that some meteoroids were broken-up already at the beginning of observation? I will discuss this question generally and also for several specific cases of

  10. Are some meteoroids rubble piles?

    NASA Astrophysics Data System (ADS)

    Borovička, Jiří

    2016-01-01

    The possibility that some meteoroids in the size range 1 - 20 meters are rubble piles i.e. assembles of boulders of various sizes held together only by small van der Waals forces, is investigated. Such meteoroids are expected to start disrupting into individual pieces during the atmospheric entry at very low dynamic pressures of ~ 25 Pa, even before the onset of ablation. The heterogeneous bodies as Almahata Sitta (asteroid 2008 TC3) and Benešov are primary candidates for rubble piles. Nevertheless, by analyzing the deceleration, wake, and light curve of the Benešov bolide, we found that the meteoroid disruption started only at a height of 70 km under dynamic pressure of 50 kPa. No evidence for a very early fragmentation was found also for the Chelyabinsk event.

  11. Thermal Conductivity of Rubble Piles

    NASA Astrophysics Data System (ADS)

    Luan, Jing; Goldreich, Peter

    2015-11-01

    Rubble piles are a common feature of solar system bodies. They are composed of monolithic elements of ice or rock bound by gravity. Voids occupy a significant fraction of the volume of a rubble pile. They can exist up to pressure P≈ {ε }Yμ , where {ε }Y is the monolithic material's yield strain and μ its rigidity. At low P, contacts between neighboring elements are confined to a small fraction of their surface areas. As a result, the effective thermal conductivity of a rubble pile, {k}{con}≈ k{(P/({ε }Yμ ))}1/2, can be orders of magnitude smaller than the thermal conductivity of its monolithic elements, k. In a fluid-free environment, only radiation can transfer energy across voids. It contributes an additional component, {k}{rad}=16{\\ell }σ {T}3/3, to the total effective conductivity, {k}{eff}={k}{con}+{k}{rad}. Here ℓ, the inverse of the opacity per unit volume, is of the order of the size of the elements, and voids. An important distinction between {k}{con} and {k}{rad} is that the former is independent of the size of the elements, whereas the latter is proportional to it. Our expression for {k}{eff} provides a good fit to the depth dependence of thermal conductivity in the top 140 cm of the lunar regolith. It also offers a good starting point for detailed modeling of thermal inertias for asteroids and satellites. Measurement of the response of surface temperature to variable insolation is a valuable diagnostic of a regolith. There is an opportunity for careful experiments under controlled laboratory conditions to test models of thermal conductivity such as the one we outline.

  12. Eros is a Rubble Pile

    NASA Astrophysics Data System (ADS)

    Asphaug, Erik

    2008-09-01

    Asteroid 433 Eros is regarded as "fractured monolith" or "shatter pile". But models of fragmentation and disruption (e.g. Benz and Asphaug 1999) predict that any large rocky asteroid should be transformed into a jumble of dust, gravel, talus and boulders, simply because it is much easier to comminute an asteroid than to catastrophically disrupt it. Sometimes the relatively high density of Eros is taken as evidence for a fractured monolithic structure, although the inferred bulk porosity of Eros ( 20-30%) is what one expects for a rubble pile, and is about the porosity of sand and talus. The focus here is that a rubble pile structure is contraindicated by the pronounced network of linear fault-like structures (Buczkowski et al. 2008), some of which radiate from recent large impacts such as Psyche, and which form rectangular boundaries around some of the medium-sized craters. This needs an explanation. Here it is proposed, and quantitatively addressed, that the majority of these faults occur just in the upper tens of meters, where cohesion exceeds gravitational stress even for loose piles of lunar-like regolith. Assuming Eros regolith has the cohesion ( 1 kPa) measured for lunar regolith, then faulting is expected to a depth of 10 m, directly analogous to how faults occur in the upper layers of beach sand. The fact that Eros has few steep slopes anywhere, except for the angles of repose within its craters, at a baseline of 100 m (Zuber et al. 2002), is satisfied by the hypothesis that Eros is a rubble pile rather than a shattered monolith. The low fault stress implied by the above, supports the findings of dense networks of linear structures, ubiquitous features which are otherwise difficult to explain as fractures in a rocky target which has not been disrupted or jumbled against its very low gravity.

  13. 15. Photo copy of drawing, June 2, 1985, SAYBROOK BREAKWATER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Photo copy of drawing, June 2, 1985, SAYBROOK BREAKWATER LIGHT, SAYBROOK, CONNECTICUT, MODERNIZATION 1985: REMOVALS. U.S. Coast Guard Civil Engineering Unit, Warwick, RI - Saybrook Breakwater Light, South tip of west end of Saybrook Breakwater, Old Saybrook, Middlesex County, CT

  14. Baseline Risk Assessment for the F-Area Burning/Rubble Pits and Rubble Pit

    SciTech Connect

    Palmer, E.

    1996-03-01

    This document provides an overview of the Savannah River Site (SRS) and a description of the F-Area Burning/Rubble Pits (BRPs) and Rubble Pit (RP) unit. It also describes the objectives and scope of the baseline risk assessment (BRA).

  15. Stair-stepped Mound

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-429, 22 July 2003

    This April 2003 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a stair-stepped mound of sedimentary rock (right of center) on the floor of a large impact crater in western Arabia Terra near 11.0oN, 4.4oW. Sedimentary rock outcrops are common in the craters of this region. The repeated thickness and uniformity of the layers that make up this mound suggest that their depositional environment was one in which cyclic or episodic events occurred over some period of time. The sediments might have been deposited in a lake, or they may have settled directly out of the atmosphere. Most of the layered material was later eroded away, leaving this circular mound and the other nearby mesas and knobs. The image is illuminated by sunlight from the lower left.

  16. Mound Supports Galileo

    SciTech Connect

    Monsanto Research Corporation

    1986-01-01

    This video describes the invention of Radioisotope Thermoelectric Generators (RTGs) at Mound Laboratory, and radioisotope heat source production from 1 watt-thermal to 2400 watts-thermal. RTGs have been used in many space vehicles, but the RTG built for the Galileo mission to orbit Jupiter is the largest. This RTG unit will produce 4400 watts-thermal and convert to 300 watts-electric. The plutonium-238 heat source assembly and test at Mound is described. The RTGs are tested under simulated mission conditions. The RTG leakage radiation is carefully measured for background compensation for on-board radiation monitoring instruments.

  17. The Strength of Rubble Pile Asteroids

    NASA Astrophysics Data System (ADS)

    Scheeres, D. J.; Sanchez, P.

    2012-12-01

    The rubble pile hypothesis for small asteroids in the Near Earth and Main Belt populations have been driven by several factors, including the observed high porosity of those bodies whose mass have been measured, the evident limitation on spin rate of asteroids larger than ~500 meters, and direct observation of the surface morphology of these bodies. Given these observations, it has been presumed that small asteroids should evolve as if they were cohesionless collections of grains. Detailed geophysical analysis of these bodies by Holsapple (Icarus 2010) show that cohesionless bodies will evolve under the addition of angular momentum by the YORP effect into more distended and, paradoxically, more slowly rotating bodies. Additional analysis in Holsapple (Icarus 2007) has shown that cohesional strength within a rubble pile could strengthen a collection of grains to the point where they could sustain rapid rotation. In our current talk we use the above as a starting point and incorporate new observations of the asteroid morphology driven by recent analysis of asteroid Itokawa by the Hayabusa science team and research on the mechanics of grains in the space environment (Scheeres et al. 2010). Analysis of images of Itokawa determined a measured size distribution of 1/d^3 for larger grains on asteroid Itokawa (Michikami et al., Earth Planets Space, 60, 13-20, 2008). Analysis of the sample shows the presence of micron sized dust on that asteroid's surface (Tsuchiyama et al., Science 333, 1125, 2011). Combining these observations provides a global indication of grain distribution within rubble piles. Even assuming a less steep distribution of 1/d^2 for dust grains smaller than 1 mm in size, the interior of Itokawa should still be dominated by the finest dust grains, with the mean grain size equal to ~ twice the smallest grain in the distribution. One implication of this result is that fines are present on the surface of the rubble pile Itokawa and thus should be distributed

  18. Mound publications for 1991

    SciTech Connect

    Nowka, Stephen L.

    1992-05-01

    This document is a compilation of all Mound formal technical publications and oral presentations for calendar year 1991. It is intended to serve as an aid to personnel in obtaining or referring to specific publications by giving the proper complete reference for each information item published during the year. Some items, such as proceedings publications, may have issue dates or periods of coverage prior to 1991; however, they were formally published during 1991.

  19. Biodiversity of Spongosorites coralliophaga (Stephens, 1915) on coral rubble at two contrasting cold-water coral reef settings

    NASA Astrophysics Data System (ADS)

    Kazanidis, Georgios; Henry, Lea-Anne; Roberts, J. Murray; Witte, Ursula F. M.

    2016-03-01

    Cold-water coral reefs (CWRs) in the northeast Atlantic harbor diverse sponge communities. Knowledge of deep-sea sponge ecology is limited and this leaves us with a fragmented understanding of the ecological roles that sponges play in CWR ecosystems. We present the first study of faunal biodiversity associated with the massive demosponge Spongosorites coralliophaga (Stephens, 1915) that typically colonizes coral debris fields of CWRs. Our study focused on the sessile fauna inhabiting sponges mixed with coral rubble at two contrasting settings in the northeast Atlantic: the shallow inshore (120-190 m water depth) Mingulay Reef Complex (MRC) and the deep offshore (500-1200 m) Logachev Mound (LM) coral province. MRC is dominated by the scleractinian Lophelia pertusa, while LM is dominated by L. pertusa and Madrepora oculata. Nine sponge-coral rubble associations were collected from MRC and four from LM. Measurements of abundance, species richness, diversity, evenness, dry biomass, and composition of sessile fauna on sponge and coral rubble microhabitats were undertaken. Differences in community composition between the two regions were mainly a response to changes in fauna with depth. Fauna composition was also different between sponge and coral rubble within each region. Infauna constituted a minor component of the sponge-associated fauna in MRC but had a higher contribution in LM. Sponge and coral rubble sessile fauna in both regions was mainly composed of cnidarians and molluscs, similarly to some previous studies. Sponges' outer surfaces at MRC were colonized by a species-rich community with high abundance and biomass suggesting that S. coralliophaga at MRC acts as a settlement surface for various organisms but such a role is not the case at LM. This difference in the role of S. coralliophaga as a biological structure is probably related to differences in fauna composition with depth, bottom current speed, and the quantity/quality of food supplied to the benthos.

  20. Lithifying Microbes Associated to Coral Rubbles

    NASA Astrophysics Data System (ADS)

    Beltran, Y.

    2015-12-01

    Microbial communities taking part in calcium carbonate lithification processes are particularly relevant to coral reef formation in as much as this lithification allows the stabilization of secondary reef structure. This second framework promotes long-term permanence of the reef, favoring the establishment of macro-reef builders, including corals. The reef-bacterial crusts formed by microbial communities are composed of magnesium calcite. Although prokaryotes are not proper calcifiers, carbonate precipitation can be induced by their metabolic activity and EPS production. Coral reefs are rapidly declining due to several variables associated to environmental change. Specifically in the Caribbean, stony coral Acropora palmata have suffered damage due to diseases, bleaching and storms. Some reports show that in highly disturbed areas wide ridges of reef rubbles are formed by biological and physical lithification. In this study we explore microbial diversity associated to lithified rubbles left after the great decline of reef-building A. palmata.

  1. Mound facility physical characterization

    SciTech Connect

    Tonne, W.R.; Alexander, B.M.; Cage, M.R.; Hase, E.H.; Schmidt, M.J.; Schneider, J.E.; Slusher, W.; Todd, J.E.

    1993-12-01

    The purpose of this report is to provide a baseline physical characterization of Mound`s facilities as of September 1993. The baseline characterizations are to be used in the development of long-term future use strategy development for the Mound site. This document describes the current missions and alternative future use scenarios for each building. Current mission descriptions cover facility capabilities, physical resources required to support operations, current safety envelope and current status of facilities. Future use scenarios identify potential alternative future uses, facility modifications required for likely use, facility modifications of other uses, changes to safety envelope for the likely use, cleanup criteria for each future use scenario, and disposition of surplus equipment. This Introductory Chapter includes an Executive Summary that contains narrative on the Functional Unit Material Condition, Current Facility Status, Listing of Buildings, Space Plans, Summary of Maintenance Program and Repair Backlog, Environmental Restoration, and Decontamination and Decommissioning Programs. Under Section B, Site Description, is a brief listing of the Site PS Development, as well as Current Utility Sources. Section C contains Site Assumptions. A Maintenance Program Overview, as well as Current Deficiencies, is contained within the Maintenance Program Chapter.

  2. Polyhedron Modeling of Rubble-Pile Asteroids

    NASA Technical Reports Server (NTRS)

    Korycansky, D. G.; Asphaug, E.

    2005-01-01

    We report on progress in modeling of asteroids as collections of rigid polyhedra ("rubble piles"). Such models are (idealized) candidates for asteroid structures: aggregates of irregular rocky subunits that are held together by self-gravity and friction. We have taken several steps toward greater realism and physical interest in construction of the models (although the gravitational fields are being treated in a simplified manner). -

  3. Geoprospection of Mound A, Etowah Mounds State Park, Georgia

    NASA Astrophysics Data System (ADS)

    Reppert, P. M.; Schneider, K. A.; Garrison, E. G.

    2005-05-01

    Mound A, located at Etowah Mounds State Park, Georgia, was the subject of a multi-sensor geoprospection study in 2001-02. Mound A, a late prehistoric mound, built by the Mississippian Culture, ca. 1250 - 1400 AD,is, due to its size, ~ 1 ha in area at the base and 20 m in height, a formidable subject for the use of shallow geoprospection techniques. Techniques used were ground radar (GPR), conductivity (EM) and electrical (resistivity) methods. Common Mid-Point (CMP) radar data produced detail on the mound interior from surface to base. Electrical pesudo-sections produced excellent detail of the mound's interior. The EM data appears relevant for only the upper half of the mound, perhaps to a depth of 10 m, and suggests significant heterogeneity in the sediment fill used in the mound's construction. Our results speak directly to the efficacy of shallow geophyscial techniques in exploring large archeological mounds and tells. Another important aspect of this study is the use of a geoprospection approach as a non-invasice methodology for characterizing culturally sensitive archaeological sites.

  4. Sulphate release from building rubble of WWII

    NASA Astrophysics Data System (ADS)

    Mekiffer, Beate; Wessolek, Gerd; Vogeler, Iris; Brettholle, Mareike

    2010-05-01

    Sulphate concentration in the upper aquifer of Berlin, Germany is increasing continuously since 40 years. In downtown Berlin they particular exceed the precaution values of drinking water ordinance. We assume that the main source of sulphate in the groundwater is technogenic material, which is part of building rubble from WW II bombing. Nearly 115 Mio t of this material have been deposited in Berlin. Our aim is, ­ to identify rubble components which contain S and to quantify the S-pool of this material ­ to identify factors, influencing the release of SO4 and ­ to predict sulphate release from building rubble of WW II We analyzed total and water soluble S of various components and the fine earth fraction of the soils containing the rubble. We investigated the influence of physical and chemical parameters on the release of SO4 using unsaturated column experiments (With an automatic percolation system). Thereby, the particle size, the flow rate and the pH of the solution has been varied. Among the components, slag shows the highest total S-contents of up to 0,7% . Lignite Coal-ashes from Lusatia, Germany are also rich in SO4. The total S of brick varies between 0,01% and 0,3%. Mortar shows S-Values between 0,08 and 0,12%. In 75% of all samples show total S of less than 0,14%. There was no significant correlation between total S-amount and water-soluble SO4, which is caused by different chemical compounds in the samples. In the percolation experiments technogenic components with grain size <2mm cause a higher density, resulting in a lower percolation velocity. The concentration of ions in the according leachate is higher than in the leachate of coarse fraction (2 - 20mm). Gypsum-rich material (10%) released constant SO4 -concentration over the whole experiment. Slag-rich material released high initial SO4-concentrations which then fastly decreased. We concluded, that the kind of technogenic component and its grain size strongly influences the release of SO4 to the

  5. Solitary wave propagation influenced by submerged breakwater

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Zuo, Qi-hua; Wang, Deng-ting; Shukrieva, Shirin

    2013-10-01

    The form of Boussinesq equation derived by Nwogu (1993) using velocity at an arbitrary distance and surface elevation as variables is used to simulate wave surface elevation changes. In the numerical experiment, water depth was divided into five layers with six layer interfaces to simulate velocity at each layer interface. Besides, a physical experiment was carried out to validate numerical model and study solitary wave propagation. "Water column collapsing" method (WCCM) was used to generate solitary wave. A series of wave gauges around an impervious breakwater were set-up in the flume to measure the solitary wave shoaling, run-up, and breaking processes. The results show that the measured data and simulated data are in good agreement. Moreover, simulated and measured surface elevations were analyzed by the wavelet transform method. It shows that different wave frequencies stratified in the wavelet amplitude spectrum. Finally, horizontal and vertical velocities of each layer interface were analyzed in the process of solitary wave propagation through submerged breakwater.

  6. The Mud-Laden Mound.

    ERIC Educational Resources Information Center

    Sams, Larry M.

    1990-01-01

    A family's trip to Winterville Indian Mounds State Park in Mississippi is described, focusing on the frustrations of a gifted six-year old who fell in the muck of the Great Temple Mound, and on the joys of seeing spectacular displays of ancient earthworks. (JDD)

  7. 7. DETAIL CENTRAL PIER (SKEWBACK) WITH BREAKWATER, UPSTREAM (EAST) SIDE. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. DETAIL CENTRAL PIER (SKEWBACK) WITH BREAKWATER, UPSTREAM (EAST) SIDE. NOTE FRACTURES ALONG BARREL ARCH EXTRADOS. - Roaring Creek Bridge, State Road 2005 spanning Roaring Creek in Locust Township, Slabtown, Columbia County, PA

  8. On the tsunami wave-submerged breakwater interaction

    SciTech Connect

    Filianoti, P.; Piscopo, R.

    2008-07-08

    The tsunami wave loads on a submerged rigid breakwater are inertial. It is the result arising from the simple calculation method here proposed, and it is confirmed by the comparison with results obtained by other researchers. The method is based on the estimate of the speed drop of the tsunami wave passing over the breakwater. The calculation is rigorous for a sinusoidal wave interacting with a rigid submerged obstacle, in the framework of the linear wave theory. This new approach gives a useful and simple tool for estimating tsunami loads on submerged breakwaters.An unexpected novelty come out from a worked example: assuming the same wave height, storm waves are more dangerous than tsunami waves, for the safety against sliding of submerged breakwaters.

  9. Integrated research on the Pen Duick cold-water coral mounds: the MiCROSYSTEMS approach

    NASA Astrophysics Data System (ADS)

    van Rooij, David; de Mol, Lies; Blamart, Dominique; Mienis, Furu; Wehrmann, Laura M.; Barbieri, Roberto; Maignien, Lois; Templer, Stefanie P.; de Haas, Henk; Henriet, Jean-Pierre

    2010-05-01

    The ESF EuroDIVERSITY MiCROSYSTEMS project aimed to turn the cold-water coral (CWC) mounds on the Pen Duick Escarpment (PDE) in the Gulf of Cadiz into a natural laboratory, exploring this highly complex biotope and to characterize its biodiversity. A common point of discussion with all other CWC mound provinces, surpassing its broad range of regional and morphological variability, concerns the driving forces regarding the initiation of these complex deep-water systems. Both oceanographic and geological processes have been proposed to play a significant role in the mound nucleation, growth and decline. During IODP Expedition 307, the importance of biogeochemical processes was already elucidated. Here, we present the preliminary results of the MD169 campaign as an integrated case study of three PDE CWC mounds: Alpha, Beta and Gamma mounds. Although cold-water corals are a common feature on the adjacent cliffs, mud volcanoes and seafloor, no actual living reef has been observed during the many ROV surveys. This multidisciplinary study aims to present a comprehensive and holistic view on the local dynamic geological and oceanographic environment. Coring data suggests (past or present) methane seepage near the Pen Duick Escarpment. Several sources and pathways are proposed, among which a stratigraphic migration through uplifted Miocene series underneath PDE. Its dominant morphology has influenced the local hydrodynamics within the course of the Pliocene, as documented by the emplacement of a sediment drift. Predominantly during post-Middle Pleistocene glacial episodes, favourable conditions were present for mound growth. An additional advantage for CWC mound nucleation near the top of PDE is offered through seepage-related carbonate crusts which might offer elevated colonization positions. Present-day seabed observations also suggested a possible important role of open coral rubble frameworks in the mound building process. These graveyards not only act as sediment trap

  10. The sediment composition and predictive mapping of facies on the Propeller Mound—A cold-water coral mound (Porcupine Seabight, NE Atlantic)

    NASA Astrophysics Data System (ADS)

    Heindel, Katrin; Titschack, Jürgen; Dorschel, Boris; Huvenne, Veerle A. I.; Freiwald, André

    2010-10-01

    Here we provide a detailed qualitative and quantitative insight on recent sediment composition and facies distribution of a cold-water coral (CWC) mound using the example of the Propeller Mound on the Irish continental margin (Hovland Mound Province, Porcupine Seabight). Five facies types on Propeller Mound are defined: (1) living coral framework, (2) coral rubble, (3) dropstone, (4) hardground, representing the on-mound facies, and (5) hemipelagic sediment facies, which describes the off-mound area. This facies definition is based on already published video-data recorded by Remotely Operated Vehicle (ROV), photo-data of gravity cores, box cores, and dredges from sediment surfaces as well as on the composition of the sediment fraction coarser than 125 μm, which has been analyzed on five selected box cores. Sediment compositions of the living coral framework and coral rubble facies are rather similar. Both sediment types are mainly produced by corals (34 and 35 wt%, respectively), planktonic foraminifers (22 and 29 wt%, respectively), benthic foraminifers (both 7 wt%), and molluscs (21 and 10 wt%, respectively), whereas the living coral framework characteristically features additional brachiopods (6 wt%). Hardgrounds are well-lithified coral rudstones rich in coral fragments (>30 surf%), foraminifers, echinoderms, and bivalves. The dropstone facies and the hemipelagic sediment typically carry high amounts of lithoclasts (36 and 53 wt%, respectively) and planktonic foraminifers (35 and 32 wt%, respectively); however, their faunal diversity is low compared with the coral-dominated facies (12 and <2 wt% coral fragments, 7 and 6 wt% benthic foraminifers, and 4 and 0 wt% balanids). Using the maximum likelihood algorithm within ArcGIS 9.2, spatial prediction maps of the previously described mound facies are calculated over Propeller Mound and are based on mound morphology parameters, ground-truthed with the sedimentary and faunal information from box cores, photographs

  11. Load transmission through ice rubble on the Gulf Molikpaq

    SciTech Connect

    Timco, G.W. )

    1993-11-01

    A test program has been performed in an ice modeling basin to measure the load apportioning through ice rubble around Gulf's Molikpaq, a steel caisson offshore structure. A model of the Molikpaq and its supporting submarine berm was built at a 1:75 scale. The Molikpaq and berm were instrumented independently, so the load apportioning could be determined. Thirty-six ice-loading events, including rubble formation from level ice as well as impacts through the rubble by extreme ice features, were analyzed. The results of the tests show that the ice rubble can deform and transmit load to the structure at force levels well below those predicted by a rigid-body analysis of the rubble.

  12. Gale Crater Mound

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    The eroded, layered deposit in Gale Crater is a mound of material rising 3 km above the crater floor. It has been sculpted by wind and possibly water to produce the dramatic landforms seen today. The origin of the sedimentary material that composes the mound remains a contested issue: was it produced from sedimentation in an ancient crater lake or by airfall onto dry land?

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

    Image information: VIS instrument. Latitude -5.1, Longitude 137.5 East (222.5 West). 19 meter/pixel resolution.

  13. Beach morphologies induced by breakwaters with different orientations

    NASA Astrophysics Data System (ADS)

    Jackson, Nancy L.; Harley, Mitchell D.; Armaroli, Clara; Nordstrom, Karl F.

    2015-06-01

    A desired outcome in the construction of a detached emerged breakwater is the formation of an accretionary salient in its lee to augment the beach, improve beach amenity and provide an additional buffer from storm waves. The extent to which this salient forms and its morphology are strongly controlled by the breakwater geometry with respect to the original shoreline, sediment availability, and local wave climate. The purpose of this paper is to identify how breakwater geometry and orientation of gaps between individual breakwaters alter the direction of waves entering the gaps and change the asymmetry of the salients. Four distinct breakwater sites along the Emilia-Romagna coastline in Northern Italy were chosen for a detailed field and desktop study comprising three-dimensional topographic and bathymetric surveys, sediment sampling, LiDAR flights and historical shoreline mapping. The orientations of the shorelines at these four sites range over 43°, resulting in different exposures to the dominant waves. The oblique orientations of the gaps between individual breakwater segments at three of the four sites effectively create a "gap window" between breakwaters favoring the exposure of short-period waves from the north and diminishing the effect of longer waves from the dominant east. Salients can be symmetrical despite an acute angle of approach of the dominant deep water waves where refraction is enhanced by offshore topography and breakwaters are parallel to the shore. Waves approaching normal to the gap window undergo less diffraction due to their shorter length relative to the gap window width and undergo less attenuation by breaking and bottom friction if they are locally generated and have short periods. Greater breaking-wave energy on the gap-facing slope of the salient can create shoreline and morphological asymmetry. The implication is that breakwater orientations can be designed or altered to selectively dampen or facilitate wave energy to enhance

  14. Threat from Rubble-Pile Asteroids

    NASA Astrophysics Data System (ADS)

    Schultz, P. H.

    2015-12-01

    While chondrites are the most common meteoroids to enter our atmosphere, they represent a small fraction of recovered falls. Most stony meteorites disrupt during entry, consumed by ablation or lost by weathering; in contrast, small iron meteorites (<10 m) disrupt and disperse to create strewnfields due to interacting atmospheric bow shocks [e.g., Passey and Melosh, 1980]. The Carancas impact crater in 2007, however, challenged our understanding [Tancredi et al., 2008]: (a) first eyewitness of a crater formed by a stony meteorite; (b) undetected thermal entry at altitude; (c) no accessory meteorite falls; (d) "explosion" (not low-speed compression) crater; (e) infrasound/seismic data indicating a high-speed entry/collision; and (f) petrologic evidence for shock deformation/melting in breccias indicative of speeds >4 km/s. Although a monolithic chondrite (~ 10 m across) might allow surviving entry, most objects of this size contain multiple flaws, ensuring atmospheric disruption. Hence, an alternative "needle model" was proposed wherein a small rubble-pile object gradually re-shaped itself during entry [Schultz, 2008], a process that minimizes drag, thermal signatures of entry, and catastrophic disruption. First proposed to account for smaller than expected craters on Venus [Schultz, 1992], such a process resembles subsequent Shoemaker-Levy entry models [Boslough and Crawford, 1997] that predicted much deeper entry than standard models. Laboratory experiments at the NASA Ames Vertical Gun Range simulated this process by breaking-up hypervelocity projectiles into a cloud of debris and tracking its path at near-full atmospheric pressure. The resulting cloud of fragments exhibited less deceleration than a solid sphere at the same speed. Moreover, shadowgraphs revealed constituent fragments "surfing" the pressure jump within the mach cone/column. Previous models proposed that crater-forming impacts must be >50-100 m in diameter in order to survive entry [Bland and

  15. Small asteroids - rubble piles or boulders?

    NASA Astrophysics Data System (ADS)

    Harris, Alan W.

    2013-10-01

    The asteroid rotation spin barrier at ~2.2 h period among asteroids 10 km > D > 200 m doesn’t prove all such asteroids are rubble piles, and the faster rotations among smaller asteroids doesn’t require monolithic strength, either. Only a very modest strength, perhaps no more than van der Waals force, might suffice to hold regolith together on a small super-fast rotator (Sanchez & Scheeres, 2013, arXif:1306.1622v1). The problem is that for a constant or only slowly varying strength with respect to diameter, the spin barrier becomes proportional to 1/D below the size where material strength is dominant, or perhaps a bit steeper if strength increases with decreasing D. What we observe in the distribution of asteroid spins versus diameter is that below D ~ 200 m, the spin barrier goes up at least ~D-3.5, if not abruptly. Models with constant or slowly varying strength fail to fit this observation, and the abrupt transition cannot be an observational selection effect: the void in the phase space of rotations would be among the easiest rotations to observe, e.g. the one conspicuous exception, 2001 OE84 (D ~ 0.7 km, P = 0.5 h) was easily and unambiguously measured (Pravec, et al. 2002, Proc. ACM 2002, ESA SP-500, 743-745). This abrupt transition is most easily explained as a real transition in material properties of asteroids in the size range ~200 m diameter, from “rubble pile” to “boulder”, although neither term may be fully descriptive of the actual structure. Two other lines of evidence suggest that this transition in properties is real: the dip in the size-frequency distribution of NEAs is maximum at ~150 m, suggesting that a transition to stronger material structure occurs about there, and we observe, e.g., Tunguska and the recent Chelyabinsk bolide, that bodies in the tens of meters size range entering the atmosphere behave more like solid rocks than rock piles (Boslough & Crawford 2008, Int. J. Imp. Eng. 35, 1441-1448). I encourage those doing computer

  16. Seismic features of Winnipegosis mounds in Saskatchewan

    SciTech Connect

    Gendzwill, D.J.

    1988-07-01

    The Winnipegosis Formation of southern Saskatchewan is characterized by reefs or reeflike mounds in its upper member. Several characteristic features of the mounds permit their identification from seismic-reflection data. These features include reflections from the flanks of the mound, a change in the reflection continuity in the middle and base of the mound, a velocity pullup under the mound, and subsidence of strata over the mound. Dissolution of the salt which surrounds the mounds sometimes occurs, resulting in a drape structure. Some or all of these features may be present at the correct seismic stratigraphic level for Winnipegosis mounds, depending on the local conditions. Subsidence of strata over the mounds indicates compaction and porosity loss from the original mound or possibly the degree of dolomitization or pressure dissolution. Salt-removal features over or adjacent to the mounds indicate fluid movements. Approximate ages can be estimated from stratigraphic thinning and thickening relationships above such features. Complications in identifying Winnipegosis mounds may arise from thin-bed effects if the mounds are not very thick compared to a seismic wavelength. Confusion may also arise from anhydrite, which may encase the mounds or which may form a thick horizontal layer at the tops of the mounds, causing an interfering signal.

  17. Earth melter with rubble walls and method of use

    DOEpatents

    Chapman, Chris C.

    1998-01-01

    The present invention is an improvement to the earth melter described and claimed in U.S. Pat. No. 5,443,618. The improvement is the use of rubble for retaining walls. More specifically, the retaining walls rest on ground level and extend above ground level piling rubble around a melt zone. A portion of the melter may be below grade wherein sidewalls are formed by the relatively undisturbed native soil or rock, and the rubble may be used as a backfill liner for the below grade sidewalls.

  18. Study of vertical breakwater reliability based on copulas

    NASA Astrophysics Data System (ADS)

    Dong, Sheng; Li, Jingjing; Li, Xue; Wei, Yong

    2016-04-01

    The reliability of a vertical breakwater is calculated using direct integration methods based on joint density functions. The horizontal and uplifting wave forces on the vertical breakwater can be well fitted by the lognormal and the Gumbel distributions, respectively. The joint distribution of the horizontal and uplifting wave forces is analyzed using different probabilistic distributions, including the bivariate logistic Gumbel distribution, the bivariate lognormal distribution, and three bivariate Archimedean copulas functions constructed with different marginal distributions simultaneously. We use the fully nested copulas to construct multivariate distributions taking into account related variables. Different goodness fitting tests are carried out to determine the best bivariate copula model for wave forces on a vertical breakwater. We show that a bivariate model constructed by Frank copula gives the best reliability analysis, using marginal distributions of Gumbel and lognormal to account for uplifting pressure and horizontal wave force on a vertical breakwater, respectively. The results show that failure probability of the vertical breakwater calculated by multivariate density function is comparable to those by the Joint Committee on Structural Safety methods. As copulas are suitable for constructing a bivariate or multivariate joint distribution, they have great potential in reliability analysis for other coastal structures.

  19. 54. POWDER MAGAZINE, VENTILATION PASSAGE ALONG REAR. NOTE STONE RUBBLE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    54. POWDER MAGAZINE, VENTILATION PASSAGE ALONG REAR. NOTE STONE RUBBLE CONSTRUCTION TO LEFT (SOUTHWEST); ENTRANCE TO A MAGAZINE TO THE RIGHT. VIEW IS NORTHWEST TO SOUTHEAST. - Fort Monroe, Fortress, Hampton, Hampton, VA

  20. 10. DETAIL OF RUBBLE MASONRY ABUTMENT ON THE SOUTH BANK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. DETAIL OF RUBBLE MASONRY ABUTMENT ON THE SOUTH BANK AND DISINTEGRATING CONCRETE FACING; VIEW FROM WEST. - Mitchell's Mill Bridge, Spanning Winter's Run on Carrs Mill Road, west of Bel Air, Bel Air, Harford County, MD

  1. 2. DETAIL OF RUBBLE ABUTMENT AT WEST END OF WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. DETAIL OF RUBBLE ABUTMENT AT WEST END OF WEST MULTNOMAH FALLS VIADUCT. - Historic Columbia River Highway, West Multnomah Falls Viaduct, West of Multnomah Falls on Historic Columbia River Highway, Troutdale, Multnomah County, OR

  2. FEATURE A. CONCRETE ANTIAIRCRAFT GUN POSITION, SHOWING CORAL RUBBLE BERM, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE A. CONCRETE ANTI-AIRCRAFT GUN POSITION, SHOWING CORAL RUBBLE BERM, VIEW FACING SOUTHEAST. - Naval Air Station Barbers Point, Battery-Anti-Aircraft Gun Position, South of Point Cruz Road & west of Coral Sea Road, Ewa, Honolulu County, HI

  3. 77. Plan of Proposed Concrete of Rubble Masonry Dam at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    77. Plan of Proposed Concrete of Rubble Masonry Dam at Frog Tanks on the Agua Fria River, Arizona. September 1903. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  4. Bizarre Crater Mound

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 5 June 2003

    The height of the interior mound of sediment inside this crater exceeds the crater rim heights by 900 meters (3,000 ft). This is a confounding problem. How does all this material get inside this crater and actually rise higher than its holding chamber? What is this material? Where did it come from? Why is it still here? It is exactly these kinds of enigmas that makes Mars so very interesting.

    Image information: VIS instrument. Latitude 12.2, Longitude 26.3 East (333.7 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  5. Structural stability of rubble-pile asteroids

    NASA Astrophysics Data System (ADS)

    Sharma, Ishan

    2013-03-01

    Granular aggregates, like fluids, do not admit all manners of shapes and rotation rates. It is hoped that an analysis of a suspected granular asteroid’s equilibrium shape and its structural stability will help confirm its rubble-pile nature, and, perhaps, even constrain the asteroid’s material parameters. Equilibrium shapes have been analyzed in the past by several investigators (Holsapple, K.A. [2001]. Icarus 154, 432-448; Harris, A.W., Fahnestock, E.G., Pravec, P. [2009]. Icarus 199, 310-318; Sharma, I., Jenkins, J.T., Burns, J.A. [2009]. Icarus 200, 304-322). Here, we extend the classical Lagrange-Dirichlet stability theorem to the case of self-gravitating granular aggregates. This stability test is then applied to probe the stability of several near-Earth asteroids, and explore the influence of material parameters such as internal friction angle and plastic bulk modulus. Finally, we consider their structural stability to close planetary encounters. We find that it is possible for asteroids to be stable to small perturbations, but unstable to strong and/or extended perturbations as experienced during close flybys. Conversely, assuming stability in certain situations, it is possible to estimate material properties of some asteroids like, for example, 1943 Anteros.

  6. The Porcupine Bank Canyon coral mounds: oceanographic and topographic steering of deep-water carbonate mound development and associated phosphatic deposition

    NASA Astrophysics Data System (ADS)

    Mazzini, A.; Akhmetzhanov, A.; Monteys, X.; Ivanov, M.

    2012-06-01

    The head of a canyon system extending along the western Porcupine Bank (west of Ireland) and which accommodates a large field of giant carbonate mounds was investigated during two cruises (INSS 2000 and TTR-13). Multibeam and sidescan sonar data (600-1,150 m water depth) suggest that the pre-existing seabed topography acts as a significant factor controlling mound distribution and shape. The mounds are concentrated along the edges of the canyon or are associated with a complex fault system traced around the canyon head, comprising escarpments up to 60 m high and several km long. The sampling for geochemical and petrographic analysis of numerous types of authigenic deposits was guided by sidescan sonar and video recordings. Calcite-cemented biogenic rubble was observed at the top and on the flanks of the carbonate mounds, being associated with both living and dead corals ( Lophelia pertusa, Madrepora oculata and occasional Desmophyllum cristagalli). This can plausibly be explained by dissolution of coral debris facilitated by strong currents along the mound tops and flanks. In turn, the dissolved carbon is recycled and precipitated as interstitial micrite. Calcite, dolomite and phosphatic hardgrounds were identified in samples from the escarpment framing the eastern part of the survey area. The laterally extensive phosphatic hardgrounds represent a novel discovery in the region, supplying hard substrata for the establishment of new coral colonies. Based on existing knowledge of regional oceanographic conditions, complemented with new CTD measurements, it is suggested that water column stratification, enhanced bottom currents, and upwelling facilitate the deposition of organic matter, followed by phosphatisation leading to the formation of phosphate-glauconite deposits. The occurrence of strong bottom currents was confirmed by means of video observations combined with acoustic and sampling data, providing circumstantial evidence of fine- to medium-grained sand

  7. Mound calorimetry for explosive surveillance

    SciTech Connect

    Shockey, G.C.; Rodenburg, W.W.

    1985-01-01

    Heat of reaction determinations of pyrotechnics and explosives is made at MRC-Mound by bomb calorimetry. Energy releases from ten calories to 94 kilocalories have been measured accurately using four different calorimeter systems. Each system is described and some heat of reaction results are given. 3 figs., 4 tabs.

  8. Modelling of Performance of Caisson Type Breakwaters under Extreme Waves

    NASA Astrophysics Data System (ADS)

    Güney Doǧan, Gözde; Özyurt Tarakcıoǧlu, Gülizar; Baykal, Cüneyt

    2016-04-01

    Many coastal structures are designed without considering loads of tsunami-like waves or long waves although they are constructed in areas prone to encounter these waves. Performance of caisson type breakwaters under extreme swells is tested in Middle East Technical University (METU) Coastal and Ocean Engineering Laboratory. This paper presents the comparison of pressure measurements taken along the surface of caisson type breakwaters and obtained from numerical modelling of them using IH2VOF as well as damage behavior of the breakwater under the same extreme swells tested in a wave flume at METU. Experiments are conducted in the 1.5 m wide wave flume, which is divided into two parallel sections (0.74 m wide each). A piston type of wave maker is used to generate the long wave conditions located at one end of the wave basin. Water depth is determined as 0.4m and kept constant during the experiments. A caisson type breakwater is constructed to one side of the divided flume. The model scale, based on the Froude similitude law, is chosen as 1:50. 7 different wave conditions are applied in the tests as the wave period ranging from 14.6 s to 34.7 s, wave heights from 3.5 m to 7.5 m and steepness from 0.002 to 0.015 in prototype scale. The design wave parameters for the breakwater were 5m wave height and 9.5s wave period in prototype. To determine the damage of the breakwater which were designed according to this wave but tested under swell waves, video and photo analysis as well as breakwater profile measurements before and after each test are performed. Further investigations are carried out about the acting wave forces on the concrete blocks of the caisson structures via pressure measurements on the surfaces of these structures where the structures are fixed to the channel bottom minimizing. Finally, these pressure measurements will be compared with the results obtained from the numerical study using IH2VOF which is one of the RANS models that can be applied to simulate

  9. Numerical experiments with rubble piles: equilibrium shapes and spins

    NASA Astrophysics Data System (ADS)

    Richardson, Derek C.; Elankumaran, Pradeep; Sanderson, Robyn E.

    2005-02-01

    We present numerical experiments investigating the shape and spin limits of self-gravitating "perfect" rubble piles that consist of identical, smooth, rigid, spherical particles with configurable normal coefficient of restitution and no sliding friction. Such constructs are currently employed in a variety of investigations, ranging from the formation of asteroid satellites to the dynamical properties of Saturn's densest rings. We find that, owing to cannonball stacking behavior, rubble piles can maintain non-spherical shapes without bulk spin, unlike a fluid, and can spin faster than a perfect fluid before shedding mass, consistent with the theory for the more general continuum rubble pile model (Holsapple, 2004, Icarus 172, 272-303). Rubble piles that reassemble following a catastrophic disruption reconfigure themselves to lie within stability limits predicted by the continuum theory. We also find that coarse configurations consisting of a small number of particles are more resistant to tidal disruption than fine configurations with many particles. Overall this study shows that idealized rubble piles behave qualitatively in a manner similar to certain granular materials, at least in the limit where global shape readjustments and/or mass shedding begins. The limits obtained here may provide constraints on the possible internal structure of some small Solar System bodies that have extreme shapes or are under high stress. Amalthea is presented as a case study.

  10. MOISTURE CONTENT AND POROSITY OF CONCRETE RUBBLE STUDY.

    SciTech Connect

    Phifer, M

    2005-10-07

    Tritium contaminated concrete rubble from the 232-F Tritium Facility was disposed in the Slit 1 Trenches 1 and 2 in 1997. A Special Analysis (SA) has been performed to evaluate any impact this disposal may have on the groundwater. The SA assumed that the disposed concrete rubble was fully saturated at the time of disposal, however if the concrete was less than fully saturated, migration of tritium out of the concrete would be slower than under fully saturated conditions. Therefore if the concrete at disposal was less than fully saturated, the PA assumption of full saturation would be a conservative assumption. In order to evaluate whether the PA assumption resulted in a conservative analysis from the standpoint of the concrete saturation, concrete rubble samples were collected from various facilities being demolished at the Savannah River Site (SRS) and evaluated for in-field moisture content, absorbable moisture, and water exchangeable porosity. The purpose of this task was to collect concrete rubble samples from various demolished SRS facilities for the purpose of determining in-field moisture content, absorbable moisture, and water exchangeable porosity. Since moisture content testing for concrete rubble is not typical, existing ASTM Standards were reviewed for method and procedure development.

  11. Paleoenvironmental setting of Paleozoic mud mounds

    SciTech Connect

    Wanless, H.R. . Dept. Geological Sciences); Tedesco, L.P. )

    1992-01-01

    Paleozoic carbonate mud mounds formed above storm wave base, which in many settings was in moderate to extremely shallow water. This is concluded by a comparative analysis of sedimentary structures, fabrics and small scale sequences occurring in Mississippian and Pennsylvanian mounds and in modern mud mounds and Halimeda bioherms. Most small mounds studied contain a shallowing sequence that represents shallowing into the zone of daily agitation. The bulk of each mound sequence is detrital deposition of layered mudstones to wackestones in the mound core and packstones to grainstones on the flanks and shoal cap. If macroskeletal fauna and flora are present, an autochthonous skeletal packstone may occur in the upper portion of the shallowing sequence beneath the detrital grainstone cap. Burrow excavations and grainy tubular tempestite infillings partially to completely modify the primary depositional fabric of all of these facies. Larger mounds studied are a composite of several to numerous smaller mound depositional sequences. High vertical relief of some larger mounds may be more the result of continued accommodation space provided by subsidence/downfaulting than be deposition in extremely deep water. Although the biotic components of carbonate mounds vary greatly through the Paleozoic, the contained sedimentary structures, fabrics and fundamental depositional sequences remain very similar. This suggests a general similarity in the mechanism and depositional setting of mound formation.

  12. Astronomical Aspects of Krakow's Monumental Mounds

    NASA Astrophysics Data System (ADS)

    Kozakiewicz, Joanna

    2015-05-01

    Krakus' mound and Wanda's mound are the largest prehistoric mounds in the region. According to the legend, they were raised by prehistoric Slavs as the burial sites of Krakow's founder - Krakus (or Krak), and his daughter - Wanda. Archaeological excavations have only been conducted on the mound of Krakus. They revealed that the mound was erected not earlier than the 1st century AD and not later than the 10th century AD. Furthermore, the studies conducted in the 1970s by professor Kotlarczyk showed that the azimuth connecting these mounds points to the sunrise on 1 May. As this day marks an important festival in the Celtic calendar - Beltaine - the two mounds could be related to the Celtic culture. This study presents the findings of the latest research.

  13. Sea Ice Friction: The Effect of Ice Rubble

    NASA Astrophysics Data System (ADS)

    Scourfield, S.; Sammonds, P. R.; Lishman, B.; Riska, K.; Marchenko, A. V.

    2015-12-01

    Ice deformation processes in the Arctic often generate ice rubble, and situations arise where ice fragments of varying size separate sea ice floes. While the shear forces between sea ice floes in direct contact with each other are controlled by ice-ice friction, what is not known is how the slip of the floes is affected by the presence of rubble between the sliding surfaces. We present the result of field experiments undertaken on fjord ice in Svea, Svalbard, which investigated the velocity and hold time dependence of sea ice friction involving ice gouge. Average air temperature for the duration of time in which experiments were run was -12.4°C, and the thickness of the level fjord ice was 70 cm. A double-direct-shear experiment was done on floating sea ice in the field, with the addition of rubble ice between the sliding surfaces. This was achieved by moving a floating ice block through a channel of open water whilst subjected to normal loading, which was transferred through regions of ice rubble on both sides of the mobile block. The ice rubble regions were 30 cm deep and 50 cm wide. The displacement of the block and the force needed to move the block were measured. The rate dependence of friction was investigated for speeds of 10-3 to 10-2 ms-1. To investigate the state dependence of friction, slide-hold-slide (SHS) tests were conducted for hold times ranging from 1 second to 18 hours. When comparing the results from these experiments with a model for ice friction presented by Schulson and Fortt (2013), similar behaviour is seen at low hold times, where the peak coefficient of friction has a linear relationship with the logarithm of hold time. This is not the case for long hold times, however, and we attribute this to thermal consolidation of the ice rubble region.

  14. Ecology and distribution of the benthic community on the monterey breakwater, monterey, california

    SciTech Connect

    Busch, S.J.

    1981-03-01

    The Monterey breakwater was studied to determine an ecological baseline. The plants and animals occupying meter square quadrats along a cross sectional transect covering the breakwater and the adjacent mud bottom out to depths of 13 meters was surveyed qualitatively and quantitatively. It is found that the differences between the populations of the inner and outer parts of the breakwater are minor and those differences are in the relative abundance of only a few species.

  15. Stellar Rubble May be Planetary Building Blocks

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Click on the image for animation Birth of 'Phoenix' Planets?

    This artist's concept depicts a type of dead star called a pulsar and the surrounding disk of rubble discovered by NASA's Spitzer Space Telescope. The pulsar, called 4U 0142+61, was once a massive star until about 100,000 years ago when it blew up in a supernova explosion and scattered dusty debris into space. Some of that debris was captured into what astronomers refer to as a 'fallback disk,' now circling the remaining stellar core, or pulsar. The disk resembles protoplanetary disks around young stars, out of which planets are thought to be born.

    Supernovas are a source of iron, nitrogen and other 'heavy metals' in the universe. They spray these elements out into space, where they eventually come together in clouds that give rise to new stars and planets. The Spitzer finding demonstrates that supernovas might also contribute heavy metals to their own planets, a possibility that was first suggested when astronomers discovered planets circling a pulsar called PSR B1257+12 in 1992.

    Birth of 'Phoenix' Planets? About the Movie This artist's animation depicts the explosive death of a massive star, followed by the creation of a disk made up of the star's ashes. NASA's Spitzer Space Telescope was able to see the warm glow of such a dusty disk using its heat-seeking infrared vision. Astronomers believe planets might form in this dead star's disk, like the mythical Phoenix rising up out of the ashes.

    The movie begins by showing a dying massive star called a red giant. This bloated star is about 15 times more massive than our sun, and approximately 40 times bigger in diameter. When the star runs out of nuclear fuel, it collapses and ultimately blows apart in what is called a supernova. A lone planet around the star is shown being incinerated by the fiery blast. Astronomers do not know if stars of this heft host planets, but if they do, the

  16. Full wave solution for hydrodynamic behaviors of pile breakwater

    NASA Astrophysics Data System (ADS)

    Zhu, Da-tong

    2013-06-01

    Rayleigh expansion is used to study the water-wave interaction with a row of pile breakwater in finite water depth. Evanescent waves, the wave energy dissipated on the fluid resistance and the thickness of the breakwater are totally included in the model. The formulae of wave reflection and transmission coefficients are obtained. The accuracy of the present model is verified by a comparison with existing results. It is found that the predicted wave reflection and transmission coefficients for the zero order are all highly consistent with the experimental data (Hagiwara, 1984; Isaacson et al., 1998) and plane wave solutions (Zhu, 2011). The losses of the wave energy for the fluid passing through slits play an important role, which removes the phenomena of enhanced wave transmission.

  17. Martian Sedimentary Basins and Central Mound Formation

    NASA Astrophysics Data System (ADS)

    Bennett, K. A.; Bell, J. F., III

    2014-12-01

    Central mounds on Mars are observed as sedimentary deposits within crater interiors, but the specific processes responsible for their formation and subsequent modification are still debated. The deposits are hypothesized to have been created by either subaerial or subaqueous processes through one of two general formation mechanisms. The prevailing hypothesis suggests that after their craters were formed, sediment filled the entire crater and was later eroded into the morphologies we observe today. Alternatively, the sediment could have been deposited as the features we observe today without any significant erosion contributing to their mound shape. We conducted a survey of central mounds that occur within craters larger than 25 km in diameter located between ± 60° latitude on Mars. We use mound locations, mound offsets within their host craters, and mound heights to address various mound formation hypotheses. The results of this survey support the hypothesis that mound sediment once filled the entire host crater and was later eroded into the features we observe today. We propose that large Martian impact craters act as simplistic sedimentary basins. These basins "catch" any sediment that is being transported through the region. Any geologic process that involves transport of material (airfall dust, explosive volcanism, impact ejecta, etc.) could have contributed to the growth of this sediment fill, although the dominant process could vary based on location. During this depositional phase, several processes (ice/frost, water, etc.) could have cemented the material; then, at some point, the environment changed from depositional to erosional, leading to the formation of isolated mounds of sediment within these craters. Our study reveals that most mounds are offset from the center of their host crater in the same direction as the regional winds. For example, the mounds in Arabia Terra are offset towards the western portion of their craters. This observation is

  18. Impact Simulations on the Rubble Pile Asteroid (2867) Steins

    NASA Astrophysics Data System (ADS)

    Deller, Jakob; Snodgrass, Colin; Lowry, Stephen C.; Price, Mark C.; Sierks, Holger

    2014-11-01

    Images from the OSIRIS camera system on board the Rosetta spacecraft (Keller et al. 2010) has revealed several interesting features on asteroid (2867) Steins. Its macro porosity of 40%, together with the shape that looks remarkably like a YORP evolved body, both indicate a rubble pile structure. A large crater on the southern pole is evidence for collisional evolution of this rubble pile asteroid. We have developed a new approach for simulating impacts on asteroid bodies that connects formation history to their collisional evolution. This is achieved by representing the interior as a ‘rubble pile’, created from the gravitational aggregation of spherical ‘pebbles’ that represent fragments from a major disruption event. These ‘pebbles’ follow a power law size function and constitute the building blocks of the rubble pile. This allows us to explicitly model the interior of rubble pile asteroids in hyper-velocity impact simulations in a more realistic way. We present preliminary results of a study validating our approach in a large series of simulated impacts on a typical small main belt rubble pile asteroid using the Smoothed Particle Hydrodynamics solver in Autodyn. We show that this approach allows us to explicitly follow the behavior of a single ‘pebble’, while preserving the expected properties of the bulk asteroid as known from observations and experiments (Holsapple 2009). On the example of Steins, we use this model to investigate if surface features like the northern hill at 75/100 degrees lon/lat distance to the largest crater (Jorda et al. 2012), or the catena of depletion pits, can be explained by the displacement of large fragments in the interior of the asteroid during the impact. We do this by following the movement of pebbles below the surface feature in simulations that recreate the shape of the impact crater.Acknowledgements: Jakob Deller thanks the Planetary Science Institute for a Pierazzo International Student Travel Award that funds

  19. Impact simulations on the rubble pile asteroid (2867) Steins

    NASA Astrophysics Data System (ADS)

    Deller, Jakob; Lowry, Stephen; Snodgrass, Colin; Price, Mark; Sierks, Holger

    2015-04-01

    Images from the OSIRIS camera system on board the Rosetta spacecraft (Keller et al. 2010) have revealed several interesting features on asteroid (2867) Steins. Its macro porosity of 40%, together with the shape that looks remarkably like a YORP evolved body, both indicate a rubble pile structure. A large crater on the southern pole is evidence for collisional evolution of this rubble pile asteroid. We have developed a new approach for simulating impacts on asteroid bodies that connects formation history to their collisional evolution. This is achieved by representing the interior as a 'rubble pile', created from the gravitational aggregation of spherical 'pebbles' that represent fragments from a major disruption event. These 'pebbles' follow a power-law size function and constitute the building blocks of the rubble pile. This allows us to explicitly model the interior of rubble pile asteroids in hyper-velocity impact simulations in a more realistic way. We present preliminary results of a study validating our approach in a large series of simulated impacts on a typical small main-belt rubble pile asteroid using the Smoothed Particle Hydrodynamics solver in LS-DYNA. We show that this approach allows us to explicitly follow the behavior of a single 'pebble', while preserving the expected properties of the bulk asteroid as known from observations and experiments (Holsapple 2009). On the example of Steins, we use this model to relate surface features like the northern hill at 75/100 degrees lon/lat distance to the largest crater (Jorda et al. 2012), or the catena of depletion pits, to the displacement of large fragments in the interior of the asteroid during the impact. We do this by following the movement of pebbles below the surface feature in simulations that recreate the shape of the impact crater. We show that while it is not straightforward to explain the formation of the hill-like structure, the formation of cracks possibly leading to depletion zones can be

  20. Geological mounds and their seismic expression

    SciTech Connect

    Swarbrick, R.E. )

    1991-03-01

    Mound geometry (convex upward structure developed above a subhorizontal surface) is common in many geological environments and frequently observed in 2-dimensions on seismic sections. Seismic mounds are typically associated with deep-water clastic sediments, e.g. submarine fans and slumps, and with a variety of carbonate depositional settings, e.g., reefs and banks, but also exist in other depositional settings. Recognition will be dependent on mound dimension, velocity contrast, amplitude strength, and the resolution of the seismic data. Since mounds can represent an important exploration target and recognition of porous, hydrocarbon-bearing section is all-important, careful restitution of the original depositional morphology from the seismic data is required. Details of present velocity distribution are critical, along with a realistic concept of any post-depositional modification, such as compaction, which may have taken place during burial. Where differential compaction is taking place, for example between sand and shale, seismic expression of morphology will be continually modified during progressive burial. Analysis of structure at the top and base of the mound can provide support for lithological interpretation based on other criteria, such as seismic facies analysis based on internal and external reflections. Modeling, using parameters from mounds in a variety of known depositional settings, illustrates many of the interpretational problems associated with seismic mounds and provides some objective criteria for analysis of mound morphology. Comparison is made with real data, principally from northwest Europe and North America.

  1. Sulphur Extraction at Bryan Mound

    SciTech Connect

    Kirby, Carolyn L; Lord, Anna C. Snider

    2015-08-01

    The Bryan Mound caprock was subjected to extens ive sulphur mining prior to the development of the Strategic Petroleum Reserve. Undoubtedl y, the mining has modified the caprock integrity. Cavern wells at Bryan Mound have been subject to a host of well integr ity concerns with many likely compromised by the cavernous capro ck, surrounding corrosive environment (H 2 SO 4 ), and associated elevated residual temperatures al l of which are a product of the mining activities. The intent of this study was to understand the sulphur mining process and how the mining has affected the stability of the caprock and how the compromised caprock has influenced the integrity of the cavern wells. After an extensiv e search to collect pert inent information through state agencies, literature sear ches, and the Sandia SPR librar y, a better understanding of the caprock can be inferred from the knowledge gaine d. Specifically, the discovery of the original ore reserve map goes a long way towards modeling caprock stability. In addition the gained knowledge of sulphur mining - subs idence, superheated corrosive wa ters, and caprock collapse - helps to better predict the post mi ning effects on wellbore integrity. This page intentionally left blank

  2. Scaling law for Dictyostelium Discoideum mounds

    NASA Astrophysics Data System (ADS)

    Voeltz, Camilla; Bodenschatz, Eberhard

    2004-03-01

    Little is known about how multicellular organisms regulate the size of their tissues during development. The eukaryote Dictyostelium Discoideum, may be studied as a model system. When starved, these amoebae aggregate and form cell mounds. These mounds develop into moving slugs and fruiting bodies consisting of a spore mass held atop a rigid stem of stalk cells. We report experiments on the development of mounds of Dicty-cells when confined to different heights. At the smallest height the amoebae are confined to a monolayer of cells in a 2d-plane. We found that the confinement inhibited the development of moving slugs and fruiting bodies. The cells aggregated and formed mounds whose size was found to be proportional to the height of the mounds. The precise mechanism is yet unknown. We will present the data and discuss possible mechanisms. This work is supported by the NSF through the Biocomplexity Program.

  3. COCARDE: new view on old mounds - an international network of carbonate mound research

    NASA Astrophysics Data System (ADS)

    Rüggeberg, A.; Foubert, A.; Vertino, A.; van Rooij, D.; Spezzaferri, S.; Henriet, J.-P.; Dullo, W.-C.; Cocarde Science Community

    2012-04-01

    Carbonate mounds are important contributors of life in different settings, from warm-water to cold-water environments, and throughout geological history. Research on modern cold-water coral carbonate mounds over the last decades made a major contribution to our overall understanding of these particular sedimentary systems. By looking to the modern carbonate mound community with cold-water corals as main framework builders, some fundamental questions could be addressed, until now not yet explored in fossil mound settings. The international network COCARDE (http://www.cocarde.eu) is a platform for exploring new insights in carbonate mound research of recent and ancient mound systems. The aim of the COCARDE network is to bring together scientific communities, studying Recent carbonate mounds in midslope environments in the present ocean and investigating fossil mounds spanning the whole Phanerozoic time, respectively. Scientific challenges in modern and ancient carbonate mound research got well defined during the ESF Magellan Workshop COCARDE in Fribourg, Switzerland (21.-24.01.2009). The Special Volume Cold-water Carbonate Reservoir systems in Deep Environments - COCARDE (Marine Geology, Vol. 282) was the major outcome of this meeting and highlights the diversity of Recent carbonate mound studies. The following first joint Workshop and Field Seminar held in Oviedo, Spain (16.-20.09.2009) highlighted ongoing research from both Recent and fossil academic groups integrating the message from the industry. The field seminar focused on mounds from the Carboniferous platform of Asturias and Cantabria, already intensively visited by industrial and academic researchers. However, by comparing ancient, mixed carbonate-siliciclastic mound systems of Cantabria with the Recent ones in the Porcupine Seabight, striking similarities in their genesis and processes in mound development asked for an integrated drilling campaign to understand better the 3D internal mound build-up. The

  4. Investigation of Hydrodynamic Parameters and the Effects of Breakwaters During the 2011 Great East Japan Tsunami in Kamaishi Bay

    NASA Astrophysics Data System (ADS)

    Ozer Sozdinler, Ceren; Yalciner, Ahmet Cevdet; Zaytsev, Andrey; Suppasri, Anawat; Imamura, Fumihiko

    2015-12-01

    The March 2011 Great East Japan Tsunami was one of the most disastrous tsunami events on record, affecting the east coast of Japan to an extreme degree. Extensive currents combined with flow depths in inundation zones account for this devastating impact. Video footage taken by the eyewitnesses reveals the destructive effect and dragging capability of strong tsunami currents along the coast. This study provides a numerical modeling study in Kamaishi Bay, calculating the damage inflicted by tsunami waves on structures and coastlines in terms of the square of the Froude number Fr 2 ; and also other calculated hydrodynamic parameters, such as the distribution of instantaneous flow depths, maximum currents and water surface elevations that occurred during this catastrophic tsunami. Analyses were performed by using the tsunami numerical modeling code NAMI DANCE with nested domains at a higher resolution. The effect of the Kamaishi breakwater on the tsunami inundation distance and coastal damage was tested by using the conditions of "with breakwater," "without breakwater," and "damaged breakwater." Results show that the difference between the hydrostatic pressure on the seaward side of the breakwater and the leeward side of the breakwater is quite high, clarifying conditions contributing to failure of the breakwater. Lower water surface elevations were calculated in the case of a breakwater existing at the entrance, a partly valid condition for the damaged breakwater case. The results are different for current velocities and Fr_{max}2 in the "with breakwater" condition due to the concentration of energy through the breakwater gaps.

  5. Data Summary Report D-Area Burning/Rubble Pits

    SciTech Connect

    Palmer, E.R.

    1994-10-01

    The purpose of this report is to verify that all analytical data collected at the D-Area Burning/Rubble Pits at the Savannah River Site for use in developing risk assessment and potential remediation procedures have been validated at the appropriate level. Any discrepancies or reasons why the data should be rejected for this purpose will be addressed. This report documents the data validation procedures used by Environmental Monitoring Section, Exploration Resources, and RUST Environment {ampersand} Infrastructure for Assigning qualifiers.

  6. Hydrodynamic performance of multiple-row slotted breakwaters

    NASA Astrophysics Data System (ADS)

    Elbisy, Moussa S.; Mlybari, Ehab M.; Helal, Medhat M.

    2016-06-01

    This study examines the hydrodynamic performance of multiple-row vertical slotted breakwaters. We developed a mathematical model based on an eigenfunction expansion method and a least squares technique for Stokes second-order waves. The numerical results obtained for limiting cases of double-row and triple-row walls are in good agreement with results of previous studies and experimental results. Comparisons with experimental measurements of the reflection, transmission, and dissipation coefficients ( C R , C T , and C E ) for double-row walls show that the proposed mathematical model adequately reproduces most of the important features. We found that for double-row walls, the C R increases with increasing wave number, kd, and with a decreasing permeable wall part, dm. The C T follows the opposite trend. The C E slowly increases with an increasing kd for lower kd values, reaches a maximum, and then decreases again. In addition, an increasing porosity of dm would significantly decrease the C R , while increasing the C T . At lower values of kd, a decreasing porosity increases the C E , but for high values of kd, a decreasing porosity reduces the C E . The numerical results indicate that, for triple-row walls, the effect of the arrangement of the chamber widths on hydrodynamic characteristics is not significant, except when kd<0.5. Double-row slotted breakwaters may exhibit a good wave-absorbing performance at kd>0.5, where by the horizontal wave force may be smaller than that of a single wall. On the other hand, the difference between double-row and triple-row vertical slotted breakwaters is marginal.

  7. Thermoregulation and ventilation of termite mounds

    NASA Astrophysics Data System (ADS)

    Korb, Judith

    2003-05-01

    Some of the most sophisticated of all animal-built structures are the mounds of African termites of the subfamily Macrotermitinae, the fungus-growing termites. They have long been studied as fascinating textbook examples of thermoregulation or ventilation of animal buildings. However, little research has been designed to provide critical tests of these paradigms, derived from a very small number of original papers. Here I review results from recent studies on Macrotermes bellicosus that considered the interdependence of ambient temperature, thermoregulation, ventilation and mound architecture, and that question some of the fundamental paradigms of termite mounds. M. bellicosus achieves thermal homeostasis within the mound, but ambient temperature has an influence too. In colonies in comparably cool habitats, mound architecture is adapted to reduce the loss of metabolically produced heat to the environment. While this has no negative consequences in small colonies, it produces a trade-off with gas exchange in large colonies, resulting in suboptimally low nest temperatures and increased CO2 concentrations. Along with the alteration in mound architecture, the gas exchange/ventilation mechanism also changes. While mounds in the thermally appropriate savannah have a very efficient circular ventilation during the day, the ventilation in the cooler forest is a less efficient upward movement of air, with gas exchange restricted by reduced surface exchange area. These results, together with other recent findings, question entrenched ideas such as the thermosiphon-ventilation mechanism or the assumption that mounds function to dissipate internally produced heat. Models trying to explain the proximate mechanisms of mound building, or building elements, are discussed.

  8. Ecological value of submerged breakwaters for habitat enhancement on a residential scale.

    PubMed

    Scyphers, Steven B; Powers, Sean P; Heck, Kenneth L

    2015-02-01

    Estuarine shorelines have been degraded since humans arrived in the coastal zone. In recent history, a major cause of habitat degradation has been the armoring of shorelines with vertical walls to protect property from erosive wave energy; however, a lack of practical alternatives that maintain or enhance ecological function has limited the options of waterfront residents and coastal zone managers. We experimentally investigated the habitat value of two configurations of submerged breakwaters constructed along an eroding shoreline in northwest Mobile Bay, AL (USA). Breakwaters comprised of bagged oyster shell or Reef Ball™ concrete domes were built by a community-based restoration effort. Post-deployment monitoring found that: bagged oyster breakwaters supported much higher densities of live ribbed mussels than Reef Ball breakwaters; both breakwater configurations supported increased species richness of juvenile and smaller fishes compared to controls; and that larger fishes did not appear to be affected by breakwater presence. Our study demonstrates that ecologically degraded shorelines can be augmented with small-scale breakwaters at reasonable cost and that these complex structures can serve as habitat for filter-feeding bivalves, mobile invertebrates, and young fishes. Understanding the degree to which these structures mitigate erosive wave energy and protect uplands will require a longer time frame than our 2-year-long study. PMID:25365947

  9. Ecological Value of Submerged Breakwaters for Habitat Enhancement on a Residential Scale

    NASA Astrophysics Data System (ADS)

    Scyphers, Steven B.; Powers, Sean P.; Heck, Kenneth L.

    2015-02-01

    Estuarine shorelines have been degraded since humans arrived in the coastal zone. In recent history, a major cause of habitat degradation has been the armoring of shorelines with vertical walls to protect property from erosive wave energy; however, a lack of practical alternatives that maintain or enhance ecological function has limited the options of waterfront residents and coastal zone managers. We experimentally investigated the habitat value of two configurations of submerged breakwaters constructed along an eroding shoreline in northwest Mobile Bay, AL (USA). Breakwaters comprised of bagged oyster shell or Reef Ball™ concrete domes were built by a community-based restoration effort. Post-deployment monitoring found that: bagged oyster breakwaters supported much higher densities of live ribbed mussels than Reef Ball breakwaters; both breakwater configurations supported increased species richness of juvenile and smaller fishes compared to controls; and that larger fishes did not appear to be affected by breakwater presence. Our study demonstrates that ecologically degraded shorelines can be augmented with small-scale breakwaters at reasonable cost and that these complex structures can serve as habitat for filter-feeding bivalves, mobile invertebrates, and young fishes. Understanding the degree to which these structures mitigate erosive wave energy and protect uplands will require a longer time frame than our 2-year-long study.

  10. Sub-rubble communities of Curaçao and Bonaire coral reefs

    NASA Astrophysics Data System (ADS)

    Meesters, E.; Knijn, R.; Willemsen, P.; Pennartz, R.; Roebers, G.; van Soest, R. W. M.

    1991-12-01

    The distribution and abundance of sessile organisms under coral rubble has been studied at Bonaire and Curaçao, Netherlands Antilles. Species richness under rubble is extremely high with at least 367 species of which sponges, tunicates and bryozoans are the most important. Shallow sub-rubble communities can be considered refuges as the majority of these species are crypt-obligate. Sub-rubble communities may also have a preserve function for sponges, but do not harbour enough corals to ensure a quick coral recolonization of the reef surface after a major disaster. Cryptic community composition is affected by depth and pollution, and differs substantially between the two neighbouring islands, possibly as a result of different bottom characteristics. Biomass of the sub-rubble communities may contribute considerably to total reef biomass. Diversity varies inversely with increased depth and increased rubble size, possibly indicating abiotic control (e.g. physical disturbance by wave action and reef slope substrate collapse).

  11. Formation of Mima mounds: A seismic hypothesis

    SciTech Connect

    Berg, A.W. )

    1990-03-01

    Mima mounds approximately 2.5 to 15 m in diameter and up to 3 m high occur on the ground surfaces at Mima Prairie, south of Olympia, Washington, in the Channeled Scabland of eastern Washington, and at many other locations in the United States and around the world. Small-scale Mima mounds can be produced experimentally by subjecting a plywood board covered with a thin veneer of loess to impacts that produce vibrations in the board. Experimentally produced mounds have characteristics that are nearly identical to those found in the field. This suggests that most Mima mounds formed as the result of seismic activity in conjunction with unconsolidated fine sediments on a relatively rigid planar substratum.

  12. Groundwater Mounding Beneath Stormwater Infiltration Basins

    NASA Astrophysics Data System (ADS)

    Nimmer, M.; Thompson, A. M.; Misra, D.

    2007-12-01

    An accurate understanding of groundwater mound formation is important in the proper design of stormwater infiltration basins since these basins are often required to recharge a portion of pre-development infiltration volume. Mound formation due to localized recharge may reduce the infiltration rate of the basin and the ability of the soil to filter pollutants. The goal of this research was to understand groundwater mounding and the potential for contaminant transport resulting from recharge beneath stormwater infiltration basins. A 0.10 ha infiltration basin serving a 9.4 ha residential subdivision in Oconomowoc, Wisconsin was used in this study. Subsurface conditions included sand and gravel material and a groundwater table at 2.3 m below grade. Three storm events, 4.9 cm, 2.8 cm, and 4.3 cm, between August 2006 and April 2007 were modeled using the two-dimensional numerical model HYDRUS. The calibrated model was used to evaluate hypothetical basin operation scenarios for various basin sizes, soil types, ponding depths, and water table depths. The groundwater mound intersected the basin floor in most scenarios with loamy sand and sandy loam soils, an unsaturated thickness of 1.52 m, and a ponding depth of 0.61 m. No groundwater table response was observed with ponding depths less than 0.31 m with an unsaturated zone thickness of 6.09 m. The mound height was most sensitive to hydraulic conductivity and unsaturated zone thickness. A 7.6 cm sediment layer delayed the time to reach maximum mound height, but had a minimal effect on the magnitude of the mound. Mound heights increased as infiltration basin size increased.

  13. Conductive heat flow at the TAG Active Hydrothermal Mound: Results from 1993-1995 submersible surveys

    NASA Astrophysics Data System (ADS)

    Becker, K.; Von Herzen, R.; Kirklin, J.; Evans, R.; Kadko, D.; Kinoshita, M.; Matsubayashi, O.; Mills, R.; Schultz, A.; Rona, P.

    We report 70 measurements of conductive heat flow at the 50-m-high, 200-m-diameter TAG active hydrothermal mound, made during submersible surveys with Alvin in 1993 and 1995 and Shinkai 6500 in 1994. The stations were all measured with 5-thermistor, 0.6- or 1-m-long Alvin heat flow probes, which are capable of determining both gradient and thermal conductivity, and were transponder-navigated to an estimated accuracy of ±5-10 m relative to the 10-m-diameter central complex of black smokers. Within 20 m of this complex, conductive heat flow values are extremely variable (0.1- > 100 W/m²), which can only be due to local spatial and possible temporal variability in the immediate vicinity of the vigorous discharge sites. A similar local variability is suggested in the “Kremlin” area of white smokers to the southeast of the black smoker complex. On the south and southeast side of the mound, there is very high heat flow (3.7- > 25 W/m²) on the sedimented terraces that slope down from the Kremlin area. Heat flow is also high (0.3-3 W/m²) in the pelagic carbonate sediments on the surrounding seafloor within a few tens of meters of the southwest, northwest, and northeast sides of the mound. On the west side of the sulfide rubble plateau that surrounds the central black smoker peak, there is a coherent belt of very low heat flow (<20 mW/m²) 20-50 m west of the smokers, suggestive of local, shallow recharge of bottom water. The three submersible surveys spanned nearly two years, but showed no indication of any temporal variability in conductive heat flow over this time scale, whether natural or induced by ODP drilling in 1994.

  14. Environmental changes and growth history of a cold-water carbonate mound (Propeller Mound, Porcupine Seabight)

    NASA Astrophysics Data System (ADS)

    Rüggeberg, Andres; Dullo, Christian; Dorschel, Boris; Hebbeln, Dierk

    2007-02-01

    On- and off-mound sediment cores from Propeller Mound (Hovland Mound province, Porcupine Seabight) were analysed to understand better the evolution of a carbonate mound. The evaluation of benthic foraminiferal assemblages from the off-mound position helps to determine the changes of the environmental controls on Propeller Mound in glacial and interglacial times. Two different assemblages describe the Holocene and Marine Isotope Stage (MIS) 2 and late MIS 3 (˜31 kyr BP). The different assemblages are related to changes in oceanographic conditions, surface productivity and the waxing and waning of the British Irish Ice Sheet (BIIS) during the last glacial stages. The interglacial assemblage is related to a higher supply of organic material and stronger current intensities in water depth of recent coral growth. During the last glaciation the benthic faunas showed high abundances of cassidulinid species, implying cold bottom waters and a reduced availability of organic matter. High sedimentation rates and the domination of Elphidium excavatum point to shelf erosion related to sea-level lowering (˜50 m) and the progradation of the BIIS onto the shelf. A different assemblage described for the on-mound core is dominated by Discanomalina coronata, Gavelinopsis translucens, Planulina ariminensis, Cibicides lobatulus and to a lower degree by Hyrrokkin sarcophaga. These species are only found or show significantly higher relative abundances in on-mound samples and their maximum contribution in the lower part of the record indicates a higher coral growth density on Propeller Mound in an earlier period. They are less abundant during the Holocene, however. This dataset portrays the boundary conditions of the habitable range for the cold-water coral Lophelia pertusa, which dominates the deep-water reefal ecosystem on the upper flanks of Propeller Mound. The growth of this ecosystem occurs during interglacial and interstadial periods, whereas a retreat of corals is documented in

  15. Wave transmission and mooring-force characteristics of pipe-tire floating breakwaters

    SciTech Connect

    Harms, Volker W.; Westerink, Joannes J.

    1980-10-01

    The results are presented of a series of prototype scale tests of a floating breakwater that incorporates massive cylindrical members (steel or concrete pipes, telephone poles, etc.) in a matrix of scrap truck or automobile tires, referred to as the Pipe-Tire Breakwater (PT-Breakwater). Tests were conducted in the large wave tank at the US Army Coastal Engineering Research Center (CERC). Breakwater modules were preassembled at SUNY in Buffalo, New York, and then transported to CERC by truck, where final assembly on location was again performed by SUNY personnel. Wave-tank tests were conducted jointly by CERC and SUNY personnel. A series of wave-tank experiments and mooring system load-deflection tests were performed, and are described. Wave-transmission and mooring-load characteristics, based on 402 separate tests, were established and are reported. (LCL)

  16. The Dangeard and Explorer canyons, South Western Approaches UK: Geology, sedimentology and newly discovered cold-water coral mini-mounds

    NASA Astrophysics Data System (ADS)

    Stewart, Heather A.; Davies, Jaime S.; Guinan, Janine; Howell, Kerry L.

    2014-06-01

    The Celtic Margin is a complex area in terms of sedimentary dynamics and evolution, with a number of submarine canyons dissecting the continental slope and outer continental shelf. The complex terrain and diverse range of sea-bed sediments play a part in submarine canyons being described as areas of high habitat heterogeneity. This study has concentrated on the heads of two canyons: Dangeard (also known as Dangaard) and Explorer (first named here) located in UK territorial waters, in water depths between 138 and 1165 m. Multibeam echosounder, 2D reflection seismic and photographic ground-truthing data have been combined to map the sea-bed geomorphology, sedimentary features and canyon megafauna of these canyons. In addition, two previously unknown provinces of cold-water coral (CWC) mini-mounds were discovered on the interfluves of the Dangeard and Explorer canyons. The study area comprises a dendritic network of gullies feeding into the canyon thalwegs. Amphitheatre rims, where slope angles are commonly in excess of 20°, occur along the margins and heads of both canyons and are interpreted as drainage basins indicative of retrogressive mass-wasting in a shelfward direction. The CWC mini-mounds occur in water depths between 250 m and 410 m, with more than 400 mounds identified. They are up to 3 m in height and 50-150 m in diameter with no sub-surface expression, suggesting these mounds are, in geological terms, relatively young and possibly Holocene in age. Biological analyses revealed that the mounds form a habitat for ophiuroids and Munida associated with Lophelia pertusa coral rubble, suggesting these mini-mounds are not present-day living features.

  17. The Eugen Seibold coral mounds offshore western Morocco: oceanographic and bathymetric boundary conditions of a newly discovered cold-water coral province

    NASA Astrophysics Data System (ADS)

    Glogowski, Silke; Dullo, Wolf-Christian; Feldens, Peter; Liebetrau, Volker; von Reumont, Jonas; Hühnerbach, Veit; Krastel, Sebastian; Wynn, Russell B.; Flögel, Sascha

    2015-08-01

    This study reports a new cold-water coral (CWC) province covering ~410 km2 off western Morocco (ca. 31°N) ~40 nautical miles north of the Agadir Canyon system between 678 and 863 m water depth, here named the Eugen Seibold coral mounds. Individual mounds are up to 12 m high with slope angles varying between 3° and 12°. Hydroacoustic data revealed mound axes lengths of 80 to 240 m. Slope angle, mound height, and density of mounds decrease with increasing water depth. The deepest mounds are composed of dead and fragmented Lophelia pertusa branches. Living CWCs, mainly L. pertusa, were sampled with box cores between 678 and 719 m water depth. Conductivity-temperature-depth (CTD) measurements revealed living CWC colonies to occur within the deeper part of the North Atlantic Central Water (NACW; conservative temperature Θ of 9.78-9.94 °C, absolute salinity SA of ca. 35.632 g/kg, and seawater density σΘ of 27.31-27.33 kg/m3). Comparable CWC reefs off Mauritania (17°N-18°N) and on the Renard Ridge (35°N) in the Gulf of Cadiz, the latter consisting only of a dead CWC fabric, are also located in the deeper layer of the NACW slightly above the Mediterranean Outflow Water. The new CWC province, with its thin cover of living corals and much larger accumulations of dead thickets and fragmented coral rubble, was successfully discovered by CTD reconnaissance applying seawater density as a potential indicator of CWC occurrences, followed by hydroacoustic mapping. U-Th isotope systematics for macroscopically altered buried Lophelia material (25 cm sediment depth) yielded absolute ages dating back to the late Holocene at least.

  18. Use of rubble from building demolition in mortars.

    PubMed

    Corinaldesi, V; Giuggiolini, M; Moriconi, G

    2002-01-01

    Because of increasing waste production and public concerns about the environment, it is desirable to recycle materials from building demolition. If suitably selected, ground, cleaned and sieved in appropriate industrial crushing plants, these materials can be profitably used in concrete. Nevertheless, the presence of masonry instead of concrete rubble is particularly detrimental to the mechanical performance and durability of recycled-aggregate concrete and the same negative effect is detectable when natural sand is replaced by fine recycled aggregate fraction. An alternative use of both masonry rubble and fine recycled material fraction could be in mortars. These could contain either recycled instead of natural sand or powder obtained by bricks crushing as partial cement substitution. In particular, attention is focused on the modification that takes place when either polypropylene or stainless steel fibers are added to these mortars. Polypropylene fibers are added in order to reduce shrinkage of mortars, stainless steel fibers for improving their flexural strength. The combined use of polypropylene fibers and fine recycled material from building demolition could allow the preparation of mortars showing good performance, in particular when coupled with bricks. Furthermore, the combined use of stainless steel fibers and mortars containing brick powder seems to be an effective way to guarantee a high flexural strength. PMID:12423051

  19. Dengue, related to rubble and building construction in Brazil.

    PubMed

    Sampaio, Angela Maria Marques; Kligerman, Débora Cynamon; Júnior, Sílvio Ferreira

    2009-11-01

    The fast-growing formation of solid waste, resulting from demographic density, presents itself as one of the most pressing problems to be addressed by governments of large cities all over the world. In Rio de Janeiro, 60% of solid waste stems from the construction industry. Although envisaged by under current municipal legislation, no application of policy regarding systematic recycling of this kind of waste exists in fact. Both sanitation experts and epidemiologists highlight that the deficient sanitary system contributes to the growth of endemic breeding sites, which may reach epidemic proportions. In Brazil, over the recent years, there has been an increase of Dengue Fever cases followed by deaths. In the first half of 2008, the State of Rio de Janeiro was plagued by an intense Dengue epidemic. The city of Rio de Janeiro alone accounted for 48.7% of the cases, in absolute values. By drawing upon an analytical method based on the interrelation between health and sanitation, the outcomes herein indicate that the city of Rio de Janeiro bears a direct relation between Dengue incidence rates and rubble formation from construction - measured by the total area built. Thus, there is a strong urge to implement recycling systems out of construction rubble as a sanitation measure in order to promote Dengue incidence reduction. PMID:19608399

  20. Stability of binaries. Part II: Rubble-pile binaries

    NASA Astrophysics Data System (ADS)

    Sharma, Ishan

    2016-10-01

    We consider the stability of the binary asteroids whose members are granular aggregates held together by self-gravity alone. A binary is said to be stable whenever both its members are orbitally and structurally stable to both orbital and structural perturbations. To this end, we extend the stability analysis of Sharma (Sharma [2015] Icarus, 258, 438-453), that is applicable to binaries with rigid members, to the case of binary systems with rubble members. We employ volume averaging (Sharma et al. [2009] Icarus, 200, 304-322), which was inspired by past work on elastic/fluid, rotating and gravitating ellipsoids. This technique has shown promise when applied to rubble-pile ellipsoids, but requires further work to settle some of its underlying assumptions. The stability test is finally applied to some suspected binary systems, viz., 216 Kleopatra, 624 Hektor and 90 Antiope. We also see that equilibrated binaries that are close to mobilizing their maximum friction can sustain only a narrow range of shapes and, generally, congruent shapes are preferred.

  1. Tidal Disruption of Rubble-Pile Comets and Asteroids

    NASA Astrophysics Data System (ADS)

    Movshovitz, Naor; Asphaug, E.; Korycansky, D.

    2010-10-01

    Following the investigations of Richardson et al. (2005) and Korycansky and Asphaug (2006, 2008), we study the shape and spin state of rubble-pile asteroids and cometary nuclei, focusing here on the process and aftermath of tidal disruption. A fast and robust commercial physics engine (www.nvidia.com/physx) is used to model thousands of polyhedral elements including self-gravity and intergranular forces such as friction and cohesion. The physics engine has been tested and validated with small scale laboratory experiments (granular avalanche, brazil-nut effects); its speed and its ability to deal with resting contacts allow us to use a variety of element shapes, from simple primitives to arbitrary polyhedra. Here we model the tidal disruption of comet Shoemaker-Levy 9 and other split comets, extending the work of Asphaug and Benz (1996) to include bodies with realistic rubble properties. One result is that a modest cohesion can account for the absence of small tidal-disruption crater chains on Ganymede and Callisto.

  2. A cold-water coral carbonate mound on the decline: Propeller Mound, northern Porcupine Seabight

    NASA Astrophysics Data System (ADS)

    Dorschel, B.; Hebbeln, D.; Rüggeberg, A.; Dullo, C.

    2003-04-01

    Radiocarbon and U/Th datings reveal that the top sediment sequence of the Propeller Mound in the Hovland Mound Province is incomplete and characterised by numerous hiatuses. Stable oxygen isotope data obtained on benthic foraminifera indicate that almost only interstadial sediments are preserved, while interglacial and full glacial sediments are missing. The Mediterranean Outflow Water (MOW), assumed to be crucial for the development of the cold-water corals Lophelia pertusa and Madrepora occulata found on Propeller Mound and in its sediments, reaches the Porcupine Seabight in its full strength only during interglacials, while it is absent during glacials. ROV observations show that under present-day conditions the MOW supports coral growth at the top of Propeller Mound, while at the same time it causes substantial erosion on its flanks, where scouring might lead to subsequent slumping. Thus, the hiatuses found in the sediment sequence of Propeller Mound are most likely caused by the strong bottom currents associated with the MOW. Especially during the terminations when the MOW circulation was re-established most of the glacial sediments, deposited under rather smooth conditions, might have been eroded and/or wasted downslope. Such erosion-favourable conditions lasted through the interglacials resulting in the ongoing removal of the interglacial sediments. During the interstadials the interplay between bottom current strength, coral growth and sedimentation resulted in sediment sequences which had a bigger chance to get preserved. Through the last 300 000 years the netto sedimentation on Propeller Mound is by far less compared to the surrounding off-mound sediments. Thus, at least over this time span the mound is shrinking relative to the seafloor around it and if this development continues into the future the Propeller Mound will get buried and follow the fate of the already buried near-by Magellan Mounds.

  3. The ecology of rubble structures of the South Atlantic Bight: A community profile. [Jetties

    SciTech Connect

    Hay, M.E.; Sutherland, J.P.

    1988-09-01

    This community profile provides an introduction to the ecology of the communities living on and around rubble structures in the South Atlantic Bight (Cape Hatteras to Cape Canaveral). The most prominent rubble structures in the bight are jetties built at the entrances to major harbors. After an initial discussion of the various kinds of rubble structures and physical factors that affect the organisms associated with them, the major portion of the text is devoted to the ecology of rubble structure habitats. Community composition, distribution, seasonality, and the recruitment patterns of the major groups of organisms are described. The major physical and biological factors affecting the organization of intertidal, sunlit subtidal, and shaded subtidal communities are presented and the potential effects of complex interactions in structuring these communities are evaluated. The profile concludes with a general review of the effects of rubble structures on nearshore sediment dynamics and shoreline evolution. 295 refs., 33 figs., 4 tabs.

  4. The giant cold-water coral mound as a nested microbial/metazoan system: physical, chemical, biological and geological picture (ESF EuroDiversity MiCROSYSTEMS)

    NASA Astrophysics Data System (ADS)

    Henriet, J. P.; Microsystems Team

    2009-04-01

    The MiCROSYSTEMS project under the ESF EUROCORES EuroDiversity scheme is a holistic and multi-scale approach in studying microbial diversity and functionality in a nested microbial/metazoan system, which thrives in deep waters: the giant cold-water coral mound. Studies on prolific cold-water coral sites have been carried out from the canyons of the Bay of Biscay to the fjords of the Norwegian margin, while the Pen Duick carbonate mound province off Morocco developed into a joint natural lab for studying in particular the impact of biogeochemical and microbial processes on modern sedimentary diagenesis within the reef sediments, in complement to the studies on I0DP Exp. 307 cores (Challenger Mound, off Ireland). Major outcomes of this research can be summarized as follows. • IODP Exp. 307 on Challenger Mound had revealed a significant prokaryotic community both within and beneath the carbonate mound. MiCROSYSTEMS unveils a remarkable degree of compartmentalization in such community from the seawater, the coral skeleton surface and mucus to the reef sediments. The occurrence of such multiple and distinct microbial compartments associated with cold-water coral ecosystems promotes opportunities for microbial diversity in the deep ocean. • New cases of co-habitation of cold-water corals and giant deep-water oysters were discovered in the Bay of Biscay, which add a new facet of macrofaunal diversity to cold-water coral reef systems. • The discovery of giant, ancient coral graveyards on the Moroccan mounds not only fuels the debate about natural versus anthropogenic mass extinction, but these open frameworks simultaneously invite for the study of bio-erosion and early diagenesis, in particular organo-mineralization, and of the possible role and significance of these thick, solid rubble patches in 3D mound-building and consolidation. • The assessment of the carbonate budget of a modern cold-water coral mound (Challenger Mound) reveals that only 33 to 40 wt % of

  5. Mound-Interface Kinetics in Dictyostelium Aggregation

    NASA Astrophysics Data System (ADS)

    Tutu, Hiroki

    2002-09-01

    The mound development of the cellular slime mold amoebae Dictyostelium discoideum is studied with an interface kinetic model for the height of cell layers. As a competitive role for the chemotaxis, we compare two types of curvature relaxations; the surface relaxation induced by cell-substrate affinity (model A), and that comes from a cell-cell adhesive effect (model B). It is found that both models are characterized by the growth law for the maximum mound height. Based on a self-similarity scaling hypothesis for the spatial structure of streaming pattern, we suggest a scaling law for the growth of mound-height hmax ˜ t1-1/α+β/α with α = 2 (4) for the model A (B) and a number 0 ≤ β < 1.

  6. Coarse fraction of soils from building rubble (WWII)

    NASA Astrophysics Data System (ADS)

    Mekiffer, Beate; Wessolek, Gerd; Scheytt, Traugott; Bussert, Robert; Nehls, Thomas

    2010-05-01

    Soils, resulting from building rubble of WWII are wide spread in whole Europe. The parent material for pedogenesis originates from different kinds of buildings, which where destroyed of different ways. Also the kind of sorting and disposing was varying for this material. So the most important feature of soils, resulting from building rubble of WWII, is their heterogeneity. We investigated samples of soils developed from building rubble to answer the following questions: ­ What are the amounts of coarse fraction and what are their main components? ­ What are the chemical properties and what is the crystalline mineral composition of technogenic components? ­ What is the release of ions from coarse technogenic components? We sieved and hand sorted the materials, used the X-ray diffractometry and X-ray fluorescence spectroscopy and measured the ions released in 1:2-extract. In most cases, the soils have a high amount of coarse fraction (> 2mm) (median 25% w/w, N=52). Dominating components in the coarse fraction are in the order of decreasing abundance: bricks, mortar (incl. plaster and stucco), slag, ashes and unburned coals. The analyzed components show alkalescent to alkaline pH-values. 75% of the samples show low electrical conductivities of up to 141 µS/cm. Bricks mainly consist of Si oxides, followed by oxides of Al, Ca, Fe, Mg and K. X-Ray-diffractometry of bricks showed, that most common minerals are clay minerals (Kaolinit, Illit, Montmorillonit and Chlorit), Quarz, and Carbonates (Calcite and Dolomite, Siderite). Bricks contain Fe-Oxides (Hematite, Goethite), Sulphates and Sulfides (Gypsum, Pyrite, Markasite) in lower amounts. 5-20 % of the minerals are x-ray-amorphous. Mortar is characterized by a high amount of silicates (nearby 80%). The samples showed a lower percentage of Al- and Ca-compounds than bricks. Chemical composition of ashes and slag varies in wide ranges, depending on their genesis. We found mainly ashes from stove heating. They contained

  7. A global survey of martian central mounds: Central mounds as remnants of previously more extensive large-scale sedimentary deposits

    NASA Astrophysics Data System (ADS)

    Bennett, Kristen A.; Bell, James F.

    2016-01-01

    We conducted a survey of central mounds within large (>25 km diameter) impact craters on Mars. We use mound locations, mound offsets within their host craters, and relative mound heights to address and extend various mound formation hypotheses. The results of this survey support the hypothesis that mound sediments once filled their host craters and were later eroded into the features we observe today. The majority of mounds are located near the boundaries of previously identified large-scale sedimentary deposits. We discuss the implications of the hypothesis that central mounds are part of previously more extensive sedimentary units that filled and overtopped underlying impact craters. In this scenario, as erosion of the sedimentary unit occurred, the sediment within impact craters was preserved slightly longer than the overlying sediment because it was sheltered by the crater walls. Our study also reveals that most mounds are offset from the center of their host crater in the same direction as the present regional winds (e.g., the mounds in Arabia Terra are offset towards the western portion of their craters). We propose that this implies that wind has been the dominant agent causing the erosion of central mounds. Mound offset (r) is normalized to each crater's radius. The Mound offset (θ) is such that 0 is north and 270 is west.

  8. Oyster Reefs as Natural Breakwaters Mitigate Shoreline Loss and Facilitate Fisheries

    PubMed Central

    Scyphers, Steven B.; Powers, Sean P.; Heck, Kenneth L.; Byron, Dorothy

    2011-01-01

    Shorelines at the interface of marine, estuarine and terrestrial biomes are among the most degraded and threatened habitats in the coastal zone because of their sensitivity to sea level rise, storms and increased human utilization. Previous efforts to protect shorelines have largely involved constructing bulkheads and seawalls which can detrimentally affect nearshore habitats. Recently, efforts have shifted towards “living shoreline” approaches that include biogenic breakwater reefs. Our study experimentally tested the efficacy of breakwater reefs constructed of oyster shell for protecting eroding coastal shorelines and their effect on nearshore fish and shellfish communities. Along two different stretches of eroding shoreline, we created replicated pairs of subtidal breakwater reefs and established unaltered reference areas as controls. At both sites we measured shoreline and bathymetric change and quantified oyster recruitment, fish and mobile macro-invertebrate abundances. Breakwater reef treatments mitigated shoreline retreat by more than 40% at one site, but overall vegetation retreat and erosion rates were high across all treatments and at both sites. Oyster settlement and subsequent survival were observed at both sites, with mean adult densities reaching more than eighty oysters m−2 at one site. We found the corridor between intertidal marsh and oyster reef breakwaters supported higher abundances and different communities of fishes than control plots without oyster reef habitat. Among the fishes and mobile invertebrates that appeared to be strongly enhanced were several economically-important species. Blue crabs (Callinectes sapidus) were the most clearly enhanced (+297%) by the presence of breakwater reefs, while red drum (Sciaenops ocellatus) (+108%), spotted seatrout (Cynoscion nebulosus) (+88%) and flounder (Paralichthys sp.) (+79%) also benefited. Although the vertical relief of the breakwater reefs was reduced over the course of our study and

  9. Interplay of instabilities in mounded surface growth

    SciTech Connect

    Chakrabarti, Buddhapriya; Dasgupta, Chandan

    2005-02-01

    We numerically study a one-dimensional conserved growth equation with competing linear (Ehrlich-Schwoebel) and nonlinear instabilities. As a control parameter is varied, this model exhibits a nonequilibrium phase transition between two mounded states, one of which exhibits slope selection and the other does not. The coarsening behavior of the mounds in these two phases is studied in detail. In the absence of noise, the steady-state configuration depends crucially on which of the two instabilities dominates the early time behavior.

  10. Simulations of impacts on rubble-pile asteroids

    NASA Astrophysics Data System (ADS)

    Deller, J.; Snodgrass, C.; Lowry, S.; Price, M.; Sierks, H.

    2014-07-01

    Rubble-pile asteroids can contain a high level of macroporosity. For some asteroids, porosities of 40 % or even more have been measured [1]. While little is known about the exact distribution of the voids inside rubble-pile asteroids, assumptions have to be made for the modeling of impact events on these bodies. Most hydrocodes do not distinguish between micro- and macroporosity, instead describing brittle material by a constitutive model as homogeneous. We developed a method to model rubble-pile structures in hypervelocity impact events explicitly. The formation of the asteroid is modelled as a gravitational aggregation of spherical `pebbles', that form the building blocks of our target. This aggregate is then converted into a high-resolution Smoothed Particle Hydrodynamics (SPH) model, which also accounts for macroporosity inside the pebbles. We present results of a study that quantifies the influence of our model parameters on the outcome of a typical impact event of two small main-belt asteroids. The existence of void space in our model increases the resistance against collisional disruption, a behavior observed before [2]. We show that for our model no a priori knowledge of the rubble-pile constituents in the asteroid is needed, as the choice of the corresponding parameters does not directly correlate with the impact outcome. The size distribution of the pebbles used as building blocks in the formation of an asteroid is only poorly constrained. As a starting point, we use a power law N(>r) ∝ r^α to describe the distribution of radii of the pebbles. Reasonable values for the slope α range around α=-2.5, as found in the size distribution of main-belt objects [3,4]. The cut-off values for pebbles, r_{min} and r_{max} are given by practical considerations: In the SPH formalism, properties are represented by weighted averages of particles within their smoothing length h, preventing the resolution of structures below that scale. Using spheres with radius in the

  11. Structural Modeling Of Rubble Piles In Two And Three Dimensions

    NASA Astrophysics Data System (ADS)

    Korycansky, Donald

    2012-10-01

    One of the puzzles about the structure of asteroids and other small bodies of the solar system is amount void space that is apparently present, from measurements of their bulk densities as compared to the mineral grain densities of their surfaces. In many cases, void fractions of 40% or more are inferred. The question arises as to whether this large void fraction is the result of large-scale internal structure ("macroporosity") or small-scale grain-density effects ("microporosity"). In this work I present results from modeling rubble piles. In particular, rubble piles are modeled as assemblages of irregular polyhedra. Modeling is done by a so-called "penalty method" where repulsive forces are applied to prevent interpenetration of the constitutent blocks. Displacements are proportional to the forces, so this is a first-order dynamics method (i.e.there is no inertia). Collision detection among the elements is done via Minkowski summation: compilation of the pairwise differences of the polyhedra vertices, followed by the application of a convex hull. Minkowski summation provides the minimum distance required to resolve a collision, but the location of the overlap region is lost. Thus, further operations are done to recover this information. Given the depth of overlaps and their locations, the positions and orientations of polyhedra are adjusted to reduce the overlap until a structure with minimal interpenetration is produced. Initial calculations done with 100 polyhedra derived from voronoi decomposition of a cube yield results with void fractions in the range of 20-25%. Further results will be reported at the DPS conference. This work was supported by NASA PG&G award NNX07AQ04G.

  12. Microwave life-detection systems for searching human subjects under earthquake rubble or behind barrier.

    PubMed

    Chen, K M; Huang, Y; Zhang, J; Norman, A

    2000-01-01

    A new sensitive microwave life-detection system which can be used to locate human subjects buried under earthquake rubble or hidden behind various barriers has been constructed. This system operating at 1150 MHz or 450 MHz can detect the breathing and heartbeat signals of human subjects through an earthquake rubble or a construction barrier of about 10-ft thickness. The basic physical principle for the operation of a microwave life-detection system is rather simple. When a microwave beam of appropriate frequency (L or S band) is aimed at a pile of earthquake rubble covering a human subject or illuminated through a barrier obstructing a human subject, the microwave beam can penetrate the rubble or the barrier to reach the human subject. When the human subject is illuminated by a microwave beam, the reflected wave from the human subject will be modulated by the subject's body movements, which include the breathing and the heartbeat. If the clutter consisting of the reflected wave from stationary background can be completely eliminated and the reflected wave from the human subject's body is properly modulated, the breathing and heartbeat signals of the subject can be extracted. Thus, a human subject buried under earthquake rubble or hidden behind barriers can be located. This system has been tested extensively in a simulated earthquake rubble in the laboratory and also in a field test using realistic earthquake rubble conducted by a Federal Emergency Management Agency (FEMA) Task Force. PMID:10646285

  13. Dynamic Thermal Structure of Imported Fire Ant Mounds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was undertaken to characterize surface temperatures of imported fire ant (Solenopsis invicta Buren, S. richteri Forel, and their hybrid) mounds as it relates to sun position and shape of the mounds, to better understand factors that affect absorption of solar radiation by the nest mound and ...

  14. Three-dimensional sampling method for characterizing ant mounds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A field-portable 3D laser scanner was employed as a means of digitizing the surface of fire ant (Solenopsis invicta Buren) mounds for analysis of shape and orientation in Mississippi and Oklahoma. Estimates of above-ground mound volume obtained through manual measurements of mound length, width, an...

  15. Mounds View Environmental Education Project, Report #1.

    ERIC Educational Resources Information Center

    Budde, Duane

    Prepared for the 1971 National Science Teachers Association (NSTA) Annual Meeting, this collection of ideas, activities, and unit plans from the Mounds View Environmental Education Project would be useful for junior and senior high school teachers and curriculum planners. Content includes: (1) a senior high course outline and daily lesson plans…

  16. Diurnal respiration of a termite mound

    NASA Astrophysics Data System (ADS)

    King, Hunter; Ocko, Samuel; Mahadevan, L.

    2014-11-01

    Many species of fungus-harvesting termites build largely empty, massive mound structures which protrude from the ground above their subterranean nests. It has been long proposed that the function of these mounds is to facilitate exchange of heat, humidity, and respiratory gases; this would give the colony a controlled climate in which to raise fungus and brood. However, the specific mechanism by which the mound achieves ventilation has remained a topic of debate, as direct measurement of internal air flows has remained difficult. By directly measuring these elusive, tiny flows with a custom sensor, we find that the mound architecture of the species Odontotermes obesus takes advantage of daily oscillations in ambient temperature to drive convection and gas transport. This contradicts previous theories, which point to internal metabolic heating and external wind as driving forces. Our result, a novel example of deriving useful work from a fluctuating scalar parameter, should contribute to better understanding insect swarm construction and possible development in passive human architecture, both of which have been spurred by previous research on termites. We acknowledge support from HFSP.

  17. Mound site environmental report for calendar year 1991

    SciTech Connect

    Bauer, L.R.

    1992-06-01

    Mound is a government-owned facility operated by EG&G Mound Applied Technologies for the U.S. Department of Energy (DOE). This integrated production, development, and research site performs work in support of DOE`s weapon and energy related programs, with emphasis on explosive, nuclear, and energy technology. The purpose of this report is to inform the public about the impact of Mound`s operations on the population and the environment. This report summarizes data from the Environmental Monitoring Program, through which Mound maintains continuous surveillance of radiological and nonradiological substances released from the facility.

  18. Independent technical review of the Mound Plant

    SciTech Connect

    Not Available

    1994-06-01

    This report documents an Independent Technical Review (ITR) of the facilities, organizations, plans, and activities required to transition particular elements of the Mound Plant from Defense Program (DP) funded operation as appropriate either to community developed reuse or safe deactivation leading to decontamination and decommissioning (D&D). The review was conducted at the request of the Dr. Willis Bixby, Deputy Assistant Secretary, U.S. Department of Energy EM-60, Office of Facility Transition and Management and is a consensus of the nine member ITR Team. Information for the review was drawn from documents provided to the ITR Team by the Miamisburg Area Office (MB) of the DOE, EG&G, the City of Miamisburg, and others; and from presentations, discussions, interviews, and facility inspections at the Mound Plant during the weeks of March 14 and March 28, 1994. During the week of April 25, 1994, the ITR Team met at Los Alamos, New Mexico to develop consensus recommendations. A presentation of the core recommendations was made at the Mound Plant on May 5, 1994. This is an independent assessment of information available to, and used by, the Mound Plant personnel. Repetition of the information is not meant to imply discovery by the ITR Team. Team members, however, acting as independent reviewers, frequently assess the information from a perspective that differs significantly from that of the Mound Plant personnel. The report is based on information obtained and conditions observed during the March 1994 review interval. The ITR process and normal site work often initiate rapid, beneficial changes in understanding and organization immediately following the review. These changes frequently alter conditions observed during the review, but the report does not address changes subsequent to the review interval.

  19. Settlement of breakwater on submarine soil due to wave-induced liquefaction

    SciTech Connect

    Oka, F.; Yashima, A.; Miura, S.; Ohmaki, S.; Kamata, A.

    1995-12-31

    The stability and deformation of the seabed in response to ocean wave loading is an important consideration in the design of offshore structures such as breakwaters, anchors, platforms, and pipelines. In this study, the instability of the sandy seabed due to the wave-induced liquefaction is investigated based on intensive field observations and computational studies. A large settlement of the breakwater on loosely deposited sand bed was observed at a small fishery port in Hokkaido, Japan. To determine the appropriate countermeasure against this large settlement, intensive field observations and computational studies were carried out. It was found that the earthquake-type liquefaction phenomenon of the foundation sandy soil brought a significant settlement of the breakwater.

  20. Prickly business: abundance of sea urchins on breakwaters and coral reefs in Dubai.

    PubMed

    Bauman, Andrew G; Dunshea, Glenn; Feary, David A; Hoey, Andrew S

    2016-04-30

    Echinometra mathaei is a common echinoid on tropical reefs and where abundant plays an important role in the control of algal communities. Despite high prevalence of E. mathaei on southern Persian/Arabian Gulf reefs, their abundance and distribution is poorly known. Spatial and temporal patterns in population abundance were examined at 12 sites between breakwater and natural reef habitats in Dubai (UAE) every 3 months from 2008 to 2010. Within the breakwater habitat, densities were greatest at shallow wave-exposed sites, and reduced with both decreasing wave-exposure and increasing depth. Interestingly, E. mathaei were significantly more abundant on exposed breakwaters than natural reef sites, presumably due to differences in habitat structure and benthic cover. Population abundances differed seasonally, with peak abundances during summer (July-September) and lower abundances in winter (December-February). Seasonal fluctuations are likely the result of peak annual recruitment pulses coupled with increased fish predation from summer to winter. PMID:26563547

  1. Environmental controls on cold-water coral mound distribution, morphology, and development in the straits of Florida

    NASA Astrophysics Data System (ADS)

    Simoes Correa, Thiago Barreto

    influenced by unidirectional flowing current, whereas the mounds on the GBB slope are influenced by tidal current regime. The GBB mounds also experience higher sedimentation rates relative to the sites away from the GBB slope. Sub-surface data document partially or completely buried mounds on the GBB sites. The sediments burying mounds are off-bank material transported downslope by mass gravity flow. Mass gravity transport creates complex slope architecture on the toe-of-slope of GBB, with canyons, slump scars, and gravity flow deposits. Cold-water corals use all three of these features as location for colonization. Coral mounds growing on such pre-existing topography keep up with off-bank sedimentation. In contrast, away from the GBB slope, off-bank sedimentation is absent and coral ridges grow independently of antecedent topography. In the sediment-starved Miami Terrace site, coral ridge initiation is related to a cemented mid-Miocene unconformity. In the center of the Straits, coral ridges and knobs develop over an unconsolidated sand sheet at the tail of the Pourtales drift. Coral features at the Miami Terrace and center of the Straits have intricate morphologies, including waveform and chevron-like ridges, which result from asymmetrical coral growth. Dense coral frameworks and living coral colonies grow preferentially on the current-facing ridge sides in order to optimize food particle capture, whereas coral rubble and mud-sized sediments accumulate in the ridge leesides. Finally, this study provides a method using solely acoustic data for discriminating habitats in which cold-water corals are actively growing. Results from this method can guide future research on and management of cold-water coral ecosystems. Taken together, spatial quantitative analyses of the large-scale, high-resolution integrated surveys indicate that cold-water coral habitats in the Straits of Florida: (1) are significantly more diverse and abundant than previously thought, and (2) can be

  2. Seismic decoupling of an explosion centered in a granite chimney rubble -- scaled experiment results. Final report

    SciTech Connect

    Keller, C.; Miller, S.; Florence, A.; Fogle, M.; Kilb, D.

    1991-12-01

    This report describes the small scale evaluation of the feasibility of significant decoupling by siting an explosion in granite rubble. The chimney characteristics scaled to laboratory dimensions were those of the PILE DRIVER event. The scaled charges were of 1 KT and 8KT in the PILE DRIVER chimney. The measure of the effect was the velocity field history in the granite outside the chimney volume with the chimney rubble and with no rubble. A number of chimney sizes and shapes were studied. The explosion process was modeled via two-din=mensional, finite-difference methods used for prediction of velocity histories at the Nevada Test Site. The result was that both the spectral shape and the magnitude of the transmitted shock wave were drastically altered. The chimney geometry was as important as the rubble characteristics.

  3. Development of a separation method for molybdenum from zirconium, niobium, and major elements of rubble samples.

    PubMed

    Shimada, Asako; Ozawa, Mayumi; Yabuki, Koshi; Kimiyama, Kazuhiro; Sato, Kenji; Kameo, Yutaka

    2014-12-01

    A method for separation of Mo from Zr, Nb, and other major elements of rubble samples from the Fukushima Daiichi Nuclear Power Station (FDNPS) was developed to enable 93Mo assay of the rubble samples. Although (93)Mo analysis has been reported in a few studies, the known separation method is tedious and time consuming, or the target is a simple material. Therefore, a simple and rapid protocol for the separation of a complex material, i.e., the rubble sample, was developed in this study. Firstly, loss of Mo during the digestion of simulated rubble samples was evaluated. Next, weight distribution coefficients (Kd's) of Zr, Nb, and Mo between an extraction chromatographic resin (tetra valent actinide resin, TEVA resin) and acid solutions (HF-HCl and HF-HNO3 solutions) were determined to obtain suitable solution conditions for the separation of Mo from Zr and Nb. Based on the obtained Kd's, a chromatographic separation scheme was designed and applied to the digested solution of the simulated rubble sample. Consequently, Mo was successfully separated from Zr, Nb and other major metal ions of the simulated rubble sample. PMID:25456594

  4. Geology of Damon Mound Salt Dome, Texas

    SciTech Connect

    Collins, E.W.

    1989-01-01

    Geological investigation of the stratigraphy, cap-rock characteristics, deformation and growth history, and growth rate of a shallow coastal diapir. Damon Mound salt dome, located in Brazoria County, has salt less than 600 feet and cap rock less than 100 feet below the surface; a quarry over the dome provides excellent exposures of cap rock as well as overlying Oligocene to Pleistocene strata. These conditions make it ideal as a case study for other coastal diapirs that lack bedrock exposures. Such investigations are important because salt domes are currently being considered by chemical waste disposal companies as possible storage and disposal sites. In this book, the author reviews previous research, presents additional data on the subsurface and surface geology at Damon Mound, and evaluates Oligocene to post-Pleistocene diapir growth.

  5. The Magellan mound province in the Porcupine Basin

    NASA Astrophysics Data System (ADS)

    Huvenne, V. A. I.; Bailey, W. R.; Shannon, P. M.; Naeth, J.; di Primio, R.; Henriet, J. P.; Horsfield, B.; de Haas, H.; Wheeler, A.; Olu-Le Roy, K.

    2007-02-01

    The Magellan mound province is one of the three known provinces of carbonate mounds or cold-water coral banks in the Porcupine Seabight, west of Ireland. It has been studied in detail using a large and varied data set: 2D and 3D seismic data, sidescan sonar imagery and video data collected during ROV deployment have been used to describe the mounds in terms of origin, growth processes and burial. The aim of this paper is to present the Magellan mounds and their setting in an integrated, holistic way. More than 1,000 densely spaced and mainly buried mounds have been identified in the area. They all seem to be rooted on one seismic reflection, suggesting a sudden mound start-up. Their size and spatial distribution characteristics are presented, together with the present-day appearance of the few mounds that reach the seabed. The underlying geology has been studied by means of fault analysis and numerical basin modelling in an attempt to identify possible hydrocarbon migration pathways below or in the surroundings of the Magellan mounds. Although conclusive evidence concerning the processes of mound initiation proves to be elusive, the results of both fault analysis and 2D numerical modelling failed to identify, with confidence, any direct pathways for focused hydrocarbon flow to the Magellan province. Diffuse seepage however may have taken place, as drainage area modelling suggests a possible link between mound position and structural features in the Hovland-Magellan area. During mound development and growth, the interplay of currents and sedimentation seems to have been the most important control. Mounds which could not keep pace with the sedimentation rates were buried, and on the few mounds which maintained growth, only a few corals survive at present.

  6. Upper Carboniferous reef mounds and climate change

    SciTech Connect

    West, R.R.; Archer, A.W. )

    1992-01-01

    Tetractinomorph demosponges (chaetetids) are a minor component of extant tropical reefs, but they were the major framebuilder of reef mounds during the Westphalian (Carboniferous). These chaetetids were confined to tropical latitudes during the Carboniferous, reached an abundance peak in the Westphalian, and then declined suddenly until the Upper Triassic. After their decline, red and green algae became the dominant reef builders of the Stephanian. The marked decline of chaetetids corresponds with the disappearance, and/or decline of other marine benthic invertebrates, as well as some terrestrial plants and is the basis for the biostratigraphic boundary between the Westphalian and Stephanian (Desmoinesian and Missourian). This biostratigraphic boundary coincides with a minor extinction event and a major'' climatic change. The Westphalian climate was wetter than that of the Stephanian, and in the midcontinent this change is recorded by a gradual decline in coals and siliciclastic lithologies and a corresponding increase in carbonate lithologies. A rise in water temperature might be expected in a drier tropical climate, and if extant chaetetids are any clue, elevated water temperature may have been detrimental. Extant chaetetids are associated with tropical coral reefs that are confined to a narrow temperature range. It is not unreasonable to suggest that elevated seawater temperatures were responsible, in part, for the disappearance of chaetetid reef mounds. Red and green algae, presumably more tolerate of higher water temperatures, became the major framebuilders of reef mounds in the Stephanian. Thus, the demise of chaetetid reef mounds, and other organisms at the end of the Westphalian, may be the result of global warming.

  7. EG G Mound Applied Technologies payroll system

    SciTech Connect

    Not Available

    1992-02-07

    EG G Mound Applied Technologies, Inc., manages and operates the Mound Facility, Miamisburg, Ohio, under a cost-plus-award-fee contract administered by the Department of Energy's Albuquerque Field Office. The contractor's Payroll Department is responsible for prompt payment in the proper amount to all persons entitled to be paid, in compliance with applicable laws, regulations, and legal decisions. The objective was to determine whether controls were in place to avoid erroneous payroll payments. EG G Mound Applied Technologies, Inc., did not have all the internal controls required by General Accounting Office Title 6, Pay, Leave, and Allowances.'' Specifically, they did not have computerized edits, separation of duties and responsibilities, and restricted access to payroll data files. This condition occurred because its managers were not aware of Title 6 requirements. As a result, the contractor could not assure the Department of Energy that payroll costs were processes accurately; and fraud, waste, or abuse of Department of Energy funds could go undetected. Our sample of 212 payroll transactions from a population of 66,000 in FY 1991 disclosed only two minor processing errors and no instances of fraud, waste or abuse.

  8. Cartografical And Geodetical Aspects Of The Krakus Mound In Cracow

    NASA Astrophysics Data System (ADS)

    Banasik, Piotr

    2015-12-01

    In this work the fate of the Krakus Mound, the oldest of all existing Krakow's mounds, has been presented. The work was carried out based on selected iconographic, cartographic and geodetic documents. Using as an example old views, panoramas of the city and maps, various functions that the Krakus Mound was fulfilling over its long history were shown. An attempt was made to document the military significance of this mound and the surrounding hills. The particular astro-geodetic importance of the Krakus Mound on the scale of the city and southern Poland region was widely discussed. The Krakus Mound also inscribed itself in the history of the use of GPS technology as well as research on the local determination of the geoid in the area of Krakow.

  9. Environmental control on cold-water carbonate mounds development

    NASA Astrophysics Data System (ADS)

    Rüggeberg, A.; Liebetrau, V.; Raddatz, J.; Flögel, S.; Dullo, W.-Chr.; Exp. 307 Scientific Party, Iodp

    2009-04-01

    Cold-water coral reefs are very abundant along the European continental margin in intermediate water depths and are able to build up large mound structures. These carbonate mounds particularly occur in distinct mound provinces on the Irish and British continental margins. Previous investigations resulted in a better understanding of the cold-water coral ecology and the development of conceptual models to explain carbonate mound build-up. Two different hypotheses were evoked to explain the origin and development of carbonate mounds, external versus internal control (e.g., Freiwald et al. 2004 versus e.g. Hovland 1990). Several short sediment cores have been obtained from Propeller Mound, Northern Porcupine Seabight, indicating that cold-water corals grew during interglacial and warm interstadial periods of the Late Pleistocene controlled by environmental and climatic variability supporting the external control hypothesis (e.g. Dorschel et al. 2005, R

  10. Experimental study of dissolved oxygen transport by regular waves through a perforated breakwater

    NASA Astrophysics Data System (ADS)

    Yin, Zegao; Yu, Ning; Liang, Bingchen; Zeng, Jixiong; Xie, Shaohua

    2016-02-01

    The perforated breakwater is an environmentally friendly coastal structure, and dissolved oxygen concentration levels are an important index to denote water quality. In this paper, oxygen transport experiments with regular waves through a vertical perforated breakwater were conducted. The oxygen scavenger method was used to reduce the dissolved oxygen concentration of inner water body with the chemicals Na2SO3 and CoCl2. The dissolved oxygen concentration and wave parameters of 36 experimental scenarios were measured with different perforated arrangements and wave conditions. It was found that the oxygen transfer coefficient through wave surface, K1 a 1, is much lower than the oxygen transport coefficient through the perforated breakwater, K2 a 2. If the effect of K1 a 1 is not considered, the dissolved oxygen concentration computation for inner water body will not be greatly affected. Considering the effect of a permeable area ratio a, relative location parameter of perforations δ and wave period T, the aforementioned data of 30 experimental scenarios, the dimensional analysis and the least squares method were used to derive an equation of K2 a 2 (K2 a 2=0.0042 a 0.5 δ 0.2 T -1). It was validated with 6 other experimental scenarios data, which indicates an approximate agreement. Therefore, this equation can be used to compute the DO concentration caused by the water transport through perforated breakwater.

  11. 3D laboratory experiments on a system of low-crested breakwaters under oblique wave attack

    NASA Astrophysics Data System (ADS)

    Papacharalampous, Georgia; Karantinos, Michalis; Giantsi, Theodora; Moutzouris, Constantinos

    2016-04-01

    Low-crested breakwaters are being increasingly used for shore protection. Hydrodynamics around coastal structures are complicated and have not been fully understood. A series of large scale (1:40) 3D laboratory experiments were carried out in the Laboratory of Harbour Works, National Technical University of Athens to investigate the wave disturbance around a system of two non-parallel to the shoreline breakwaters. The structures were of the type of low-crested, permeable and attacked by obliquely incident waves. Three different water depths were tested in the basin with a range of various different spectra. The transmission and reflection coefficients were measured in the middle of each breakwater. For this purpose, 1 gauge and 4 gauges (in line) were placed on the landward and seaward side of each breakwater respectively. The effect of diffraction is incorporate at the measured wave heights. The measured coefficients are being compared to their corresponding estimated using existing empirical formulas. Most of those formulas neglect wave obliquity.

  12. Experimental Investigation of Cylindrical Floating Breakwater Performance with different mooring configurations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Floating breakwaters are typically used on limited-fetch water bodies, such as lakes, reservoirs, and bays, where wavelengths are relatively short. They are also often preferred for sites with large water level changes. Common uses are to protect small marinas or for shoreline erosion control. While...

  13. Mound site environmental report for calendar year 1992

    SciTech Connect

    Bauer, L.R.

    1993-07-01

    The purpose of this report is to inform the public about the impact of Mound operations on the population and the environment. Mound is a government-owned facility operated by EG&G Mound Applied Technologies for the US Department of Energy (DOE). This integrated production, development, and research site performs work in support of DOE`s weapon and energy related programs, with emphasis on explosive, nuclear and energy technologies.

  14. Temporal Evolution of A Carbonate Mound In The NE Atlantic

    NASA Astrophysics Data System (ADS)

    Dorschel, B.; Rüggeberg, A.; Hebbeln, D.; Dullo, C.; Freiwald, A.

    Even though carbonate mounds are quite common structures along the northeast At- lantic margin their history remains largely unknown. Besides the main question, what causes the initial development of these mounds; also their latest evolution in response to changing environmental conditions receives more and more interest. Here, this question has been tackled by new sets of stable isotope data, which provide informa- tion about the growth and accumulation pattern of these mounds for the last 100 ka. The investigated Propeller Mound (52r09'N/12r46'W) is part of the Hovland Mound Province located in the northern Porcupine Seabight. Its base is located in 800 m wa- ter depth and it expands 2 km in N-S direction and 0.7 km in E-W direction. Its top rises up to 150 m above the surrounding seafloor. In September 2000 eight gravity cores have been collected from the Propeller Mound and the surrounding area. Four cores taken from the mound contain cold-water corals and coral fragments in a matrix of silt and clay. The other cores collected from a moat around the mound and from a drift body in the northeast contain mainly sandy silty clays. All off-mound cores are easy to correlate using proxies like Ca ore Fe content. Inter-core correlations with on- mound cores turned out to be difficult. Fragments of the cold-water corals Lophelia pertusa and Madrepora occulata overprint the hemipelagic background signal. Here we use stable isotope data from benthic foraminifers for an inter-core correlation. In combination with 14C ages these data provide information about the evolutionof the mounds in relation to the off-mound area with respect to climate variations during the last 100 ka.

  15. Rubble-Pile Minor Planet Sylvia and Her Twins

    NASA Astrophysics Data System (ADS)

    2005-08-01

    the triple asteroid system showing the large asteroid 87 Sylvia spinning at a rapid rate and surrounded by two smaller asteroids (Remus and Romulus) in orbit around it. This computer animation is also available in broadcast quality to the media (please contact Herbert Zodet). One of these asteroids was 87 Sylvia, which was known to be double since 2001, from observations made by Mike Brown and Jean-Luc Margot with the Keck telescope. The astronomers used NACO to observe Sylvia on 27 occasions, over a two-month period. On each of the images, the known small companion was seen, allowing Marchis and his colleagues to precisely compute its orbit. But on 12 of the images, the astronomers also found a closer and smaller companion. 87 Sylvia is thus not double but triple! Because 87 Sylvia was named after Rhea Sylvia, the mythical mother of the founders of Rome [3], Marchis proposed naming the twin moons after those founders: Romulus and Remus. The International Astronomical Union approved the names. Sylvia's moons are considerably smaller, orbiting in nearly circular orbits and in the same plane and direction. The closest and newly discovered moonlet, orbiting about 710 km from Sylvia, is Remus, a body only 7 km across and circling Sylvia every 33 hours. The second, Romulus, orbits at about 1360 km in 87.6 hours and measures about 18 km across. The asteroid 87 Sylvia is one of the largest known from the asteroid main belt, and is located about 3.5 times further away from the Sun than the Earth, between the orbits of Mars and Jupiter. The wealth of details provided by the NACO images show that 87 Sylvia is shaped like a lumpy potato, measuring 380 x 260 x 230 km (see ESO PR Photo 25a/05). It is spinning at a rapid rate, once every 5 hours and 11 minutes. The observations of the moonlets' orbits allow the astronomers to precisely calculate the mass and density of Sylvia. With a density only 20% higher than the density of water, it is likely composed of water ice and rubble

  16. A lone biodetrital mound in the Chesterian (Carboniferous) of Alabama?

    USGS Publications Warehouse

    Kopaska-Merkel, D. C.; Haywick, D.W.

    2001-01-01

    A carbonate mound in the Chesterian Bangor Limestone of Lawrence County, Alabama, consists chiefly of packstone and grainstone dominated by echinoderm ossicles and fragments of fenestrate bryozoans. In-situ colonies of the rugose coral Caninia flaccida comprise about 8% of the mound by volume. The exposed portion of the mound is approximately 25 m wide, 1.6 m thick at the thickest point and roughly circular in plan. The mound developed on top of a shallow ooid shoal that had been cemented and stabilised during an earlier episode of sub-aerial exposure. Subsequent flooding of the exposed shoal surface permitted establishment of the mound biota. Lateral and vertical facies relationships suggest that the mound possessed about 45 cm of synoptic relief when fully developed. Rugose corals, fenestrate and ramose bryozoans, stalked echinoderms, and sessile soft-bodied organisms encrusted by foraminifera colonised the shoal, forming a mound. Baffling resulted in deposition of mixed-fossil packstone containing locally derived debris and coated grains from the surrounding sea floor. Strong currents within the mound are indicated by preferred orientation of corals and by coarse, commonly cross-stratified grainstone in channels between neighboring coral colonies. Corals are most abundant on the windward side of the mound, where they account for about 13% of the mound compared to 6- 10% in the central part of the mound, and 2-4% on the leeward flank. Biodetrital mounds such as the one described here are uncommon in upper Paleozoic strata and previously unknown in the Bangor Limestone. Of 10 carbonate buildups we examined in the Bangor in Alabama and Tennessee, only one is a biodetrital mound. Two are rugose coral-microbial reefs, one is a coral biostrome, and six are dominated by microbialite. The Bangor shelf, previously interpreted as sedimentologically simple, appears to contain many small mounds of quite varied characteristics. Also, the discovery of a biodetrital mound in

  17. The Goodlett-Denny mound: a glimpse at 45 years of Pennsylvania treethrow mound evolution with implications for mass wasting

    NASA Astrophysics Data System (ADS)

    Small, Thomas W.

    1997-03-01

    A rootplate/mound formed by the uprooting of a black cherry tree ( Prunus serotina) in Potter County, Pennsylvania, was photographed in 1950 near the time of formation and again in 1952 and 1963 by J.C. Goodlett and C.S. Denny. The mound was located and photographed by the author in 1989 with the aid of background trees with identifying peculiarities and using the earlier consistent perspectives. Between 1950 and 1963 most of the rootmass had decomposed, leaving a mound with an estimated volume of 5.28 m 3 in 1963. By 1989 the mound had lost 60% of its 1963 height and its volume had diminished to 2.09 m 3. Mean annual erosion on the mound from 1989 to 1995 was much less than during the 1963-1989 period indicating a diminishing sediment contribution to the forest floor commensurate with lowering of the mound surface.

  18. Physical modeling of long-wave run-up mitigation using submerged breakwaters

    NASA Astrophysics Data System (ADS)

    Lee, Yu-Ting; Wu, Yun-Ta; Hwung, Hwung-Hweng; Yang, Ray-Yeng

    2016-04-01

    Natural hazard due to tsunami inundation inland has been viewed as a crucial issue for coastal engineering community. The 2004 India Ocean tsunami and the 2011 Tohoku earthquake tsunami were caused by mega scale earthquakes that brought tremendous catastrophe in the disaster regions. It is thus of great importance to develop innovative approach to achieve the reduction and mitigation of tsunami hazards. In this study, new experiments have been carried out in a laboratory-scale to investigate the physical process of long-wave through submerged breakwaters built upon a mild slope. Solitary-wave is employed to represent the characteristic of long-wave with infinite wavelength and wave period. Our goal is twofold. First of all, through changing the positions of single breakwater and multiple breakwaters upon a mild slope, the optimal locations of breakwaters can be pointed out by means of maximum run-up reduction. Secondly, through using a state-of-the-art measuring technique Bubble Image Velocimetry, which features non-intrusive and image-based measurement, the wave kinematics in the highly aerated region due to solitary-wave shoaling, breaking and uprush can be quantitated. Therefore, the mitigation of long-wave due to the construction of submerged breakwaters built upon a mild slope can be evaluated not only for imaging run-up and run-down characteristics but also for measuring turbulent velocity fields due to breaking wave. Although we understand the most devastating tsunami hazards cannot be fully mitigated with impossibility, this study is to provide quantitated information on what kind of artificial coastal structure that can withstand which level of wave loads.

  19. Investigation on bragg reflection of surface water waves induced by a train of fixed floating pontoon breakwaters

    NASA Astrophysics Data System (ADS)

    Ouyang, Huei-Tau; Chen, Kue-Hong; Tsai, Chi-Ming

    2015-11-01

    The water wave characteristics of Bragg reflections from a train of fixed floating pontoon breakwaters was studied numerically. A numerical model of boundary discretization type was developed to calculate the wave field. The model was verified by comparing to analytical data in literature and good agreements were achieved. Series of parametric studies were conducted systematically to investigate the dependence of the reflected coefficients by the Bragg scattering on the design variables, including the spacing between the breakwaters, the total number of installed breakwaters, the draft and width do the breakwater, and wave length. Certain wave characteristics of the Bragg reflections were observed and discussed in details which might be of help for practical engineering applications in shoreline protection from incident waves.

  20. Structural Failure Condition for Bifurcated Rubble Pile Asteroids

    NASA Astrophysics Data System (ADS)

    Hirabayashi, M.; Scheeres, D. J.

    2014-12-01

    The present study investigates the structural failure conditions of uniformly rotating bifurcated asteroids with cohesion due to a static spin-up. We apply a newly derived technique (Hirabayashi and Scheeres, submitted) that probes the failure state of an asteroid. The technique determines an upper bound condition for structural failure of a slice normal to the minimum moment of inertia axis. The detailed study of these failure modes for cohesive, rotating rubble pile asteroid is motivated by recent observations of 'active asteroids,' bodies which are seemingly disintegrating and fissioning due to their rapid spin rates (Jewitt et al. 2013, 2014; Hirabayashi et al. 2014). Figure 1 shows the shape of 4486 Mithra. We compare 3 slices, slices 1 and 3 including the knobs and slice 2 being the neck (Fig. 1), to determine a more precise condition for structural failure. Figures 2 and 3 describe the limit of friction angle with cohesion of 0 Pa and 500 Pa, respectively. The narrow solid, dashed, and dotted lines give the limits of slices 1, 2, and 3, respectively. The bold solid lines indicate the limit of the total volume, i.e., the whole volume reaching the failure point, and that of the partial volume, i.e., the most sensitive condition among the slices. The shadowed areas show the structurally stable regions. The results show that Mithra's failure locations change as a function of its spin periods and cohesion. For the cohesionless case, the knobs are more sensitive to structural failure than the neck at a spin period ranging from 3.8 hr to 4.8 hr, while the neck fails first at other spin periods. For the 500 Pa cohesion case, the limits of friction angle shift to higher spin periods. Also, at higher spin periods, we find that a lower friction angle is sometimes stronger than a higher friction angle. This comes from the fact that under constant cohesion a lower friction angle can give wider stable regions below the yield envelope. Our study reveals that there exits a

  1. MODELING DYNAMIC THERMAL PROPERTIES OF IMPORTED FIRE ANT MOUNDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ground-based thermal infrared imagery, 3-dimensional modeling, and spatial analyses were used to model daily fluctuation in the temperature of imported fire ant mounds and their surroundings. The thermal center of the mound moved in a predictable fashion from east-southeast to west-southwest during...

  2. SIMULATING ASTEROID RUBBLE PILES WITH A SELF-GRAVITATING SOFT-SPHERE DISTINCT ELEMENT METHOD MODEL

    SciTech Connect

    Sanchez, Paul; Scheeres, Daniel J.

    2011-02-01

    This paper applies a soft-sphere distinct element method Granular Dynamics code to simulate asteroid regolith and rubble piles. Applications to regolith studies in low gravity are also studied. Then an algorithm to calculate self-gravity is derived and incorporated for full-scale simulations of rubble-pile asteroids using Granular Dynamics techniques. To test its validity, the algorithm's results are compared with the exact direct calculation of the gravitational forces. Further avenues to improve the performance of the algorithm are also discussed.

  3. Morphology and environment of cold-water coral carbonate mounds on the NW European margin

    NASA Astrophysics Data System (ADS)

    Wheeler, A. J.; Beyer, A.; Freiwald, A.; de Haas, H.; Huvenne, V. A. I.; Kozachenko, M.; Olu-Le Roy, K.; Opderbecke, J.

    2007-02-01

    Cold-water coral carbonate mounds, owing their presence mainly to the framework building coral Lophelia pertusa and the activity of associated organisms, are common along the European margin with their spatial distribution allowing them to be divided into a number of mound provinces. Variation in mound attributes are explored via a series of case studies on mound provinces that have been the most intensely investigated: Belgica, Hovland, Pelagia, Logachev and Norwegian Mounds. Morphological variation between mound provinces is discussed under the premise that mound morphology is an expression of the environmental conditions under which mounds are initiated and grow. Cold-water coral carbonate mounds can be divided into those exhibiting “inherited” morphologies (where mound morphology reflects the morphology of the colonised features) and “developed” morphology (where the mounds assume their own gross morphology mainly reflecting dominant hydrodynamic controls). Finer-scale, surface morphological features mainly reflecting biological growth forms are also discussed.

  4. Asphalt mounds and associated biota on the Angolan margin

    NASA Astrophysics Data System (ADS)

    Jones, Daniel O. B.; Walls, Anne; Clare, Michael; Fiske, Mike S.; Weiland, Richard J.; O'Brien, Robert; Touzel, Daniel F.

    2014-12-01

    Release of hydrocarbons from sediments is important in increasing habitat heterogeneity on deep ocean margins. Heterogeneity arises from variation in abiotic and biotic conditions, including changes in substratum, geochemistry, fluid flow, biological communities and ecological interactions. The seepage of heavy hydrocarbons to the seafloor is less well studied than most other cold seep systems and may lead to the formation of asphalt mounds. These have been described from several regions, particularly the Gulf of Mexico. Here, we describe the structure, potential formation and biology of a large asphalt mound province in Block 31SE Angola. A total of 2254 distinct mound features was identified by side-scan sonar, covering a total area of 3.7 km2 of seafloor. The asphalt mounds took a number of forms from small (<0.5 m diameter; 13% observations) mounds to large extensive (<50 m diameter) structures. Some of the observed mounds were associated with authigenic carbonate and active seepage (living chemosynthetic fauna present in addition to the asphalt). The asphalt mounds are seabed accumulations of heavy hydrocarbons formed from subsurface migration and fractionation of reservoir hydrocarbons primarily through a network of faults. In Angola these processes are controlled by subsurface movement of salt structures. The asphalt mounds were typically densely covered with epifauna (74.5% of mounds imaged had visible epifauna) although individual mounds varied considerably in epifaunal coverage. Of the 49 non-chemosynthetic megafaunal taxa observed, 19 taxa were only found on hard substrata (including asphalt mounds), 2 fish species inhabited the asphalt mounds preferentially and 27 taxa were apparently normal soft-sediment fauna. Antipatharians (3.6±2.3% s.e.) and poriferans (2.6±1.9% s.e.) accounted for the highest mean percentage of the observed cover, with actinarians (0.9±0.4% s.e.) and alcyonaceans (0.4±0.2% s.e.) covering smaller proportions of the area

  5. Environmental assessment for Mound Plant decontamination and decommissioning projects, Mound Plant, Miamisburg, Ohio

    SciTech Connect

    1995-05-01

    The U.S. Department of Energy (DOE) has prepared an Environmental Assessment (EA) for seven decontamination and decommissioning (D&D) projects at the Mound Plant in Miamisburg, Ohio, that have not been previously addressed in the Final Environmental Impact Statement for the Mound Facility (June 1979). Based on the information presented in the EA, the DOE has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement (EIS) is not required and the Department is issuing this Finding of No Significant Impact (FONSI).

  6. Artificial breakwaters as garbage bins: Structural complexity enhances anthropogenic litter accumulation in marine intertidal habitats.

    PubMed

    Aguilera, Moisés A; Broitman, Bernardo R; Thiel, Martin

    2016-07-01

    Coastal urban infrastructures are proliferating across the world, but knowledge about their emergent impacts is still limited. Here, we provide evidence that urban artificial reefs have a high potential to accumulate the diverse forms of litter originating from anthropogenic activities around cities. We test the hypothesis that the structural complexity of urban breakwaters, when compared with adjacent natural rocky intertidal habitats, is a driver of anthropogenic litter accumulation. We determined litter abundances at seven sites (cities) and estimated the structural complexity in both urban breakwaters and adjacent natural habitats from northern to central Chile, spanning a latitudinal gradient of ∼15° (18°S to 33°S). Anthropogenic litter density was significantly higher in coastal breakwaters when compared to natural habitats (∼15.1 items m(-2) on artificial reefs versus 7.4 items m(-2) in natural habitats) at all study sites, a pattern that was temporally persistent. Different litter categories were more abundant on the artificial reefs than in natural habitats, with local human population density and breakwater extension contributing to increase the probabilities of litter occurrence by ∼10%. In addition, structural complexity was about two-fold higher on artificial reefs, with anthropogenic litter density being highest at intermediate levels of structural complexity. Therefore, the spatial structure characteristic of artificial reefs seems to enhance anthropogenic litter accumulation, also leading to higher residence time and degradation potential. Our study highlights the interaction between coastal urban habitat modification by establishment of artificial reefs, and pollution. This emergent phenomenon is an important issue to be considered in future management plans and the engineering of coastal ecosystems. PMID:27149151

  7. Recovery in rubble fields: long-term impacts of blast fishing.

    PubMed

    Fox, Helen E; Pet, Jos S; Dahuri, Rokhmin; Caldwell, Roy L

    2003-08-01

    This paper presents initial results from a study of factors that inhibit or enhance hard coral recovery in rubble fields created by blast fishing in Komodo National Park and Bunaken National Park, Indonesia. Within nine sites monitored since 1998, there was no significant natural recovery. Levels of potential source coral larvae were assessed with settlement tiles in the rubble fields and in nearby high coral cover sites. Rubble movement was measured and shown to be detrimental to small scleractinians, especially in high current areas. In shallow water (2-6 m deep), rubble is often overgrown by soft corals and corallimorpharians, which inhibit hard coral survival. There is increased scleractinian recruitment in quadrats cleared of soft coral, and Acropora nubbins transplanted into soft coral fields suffer greater mortality than those transplanted above the soft coral canopy. Gaining an understanding of the prognosis for coral recovery is essential not only in order to assess the long-term impacts of blast fishing, but also to improve management decisions about protection of intact reefs and potential restoration of damaged areas. PMID:12907196

  8. Peak mooring forces in the horizontal interlaced multi-layered moored floating pipe breakwater

    NASA Astrophysics Data System (ADS)

    Mane, Vishwanath; Rajappa, Sacchi; Rao, Subba; Vittal, Hegde A.

    2011-06-01

    Present study aims to investigate the influence of relative breakwater width W/L (W=width of breakwater, L=wavelength), wave steepness Hi/gT2 (Hi=incident wave height, T=wave period) and relative wave height d/W (d=water depth) on forces in the moorings of horizontal interlaced multi-layered moored floating pipe breakwater (HIMMFPB) model. Studies were conducted on scaled down physical models having three layers of Poly Vinyl Chloride (PVC) pipes, wave steepness Hi/gT2 varying from 0.063 to 0.849, relative width W/L varying from 0.4 to 2.65 and relative spacing S/D=2 (S=horizontal centre-to-centre spacing of pipes, D=diameter of pipes). Peak mooring forces were also measured and data collected is analyzed by plotting non-dimensional graphs depicting variation of fs/γW2 (fs=Sea side Mooring force, γ=specific weight of water) & fl/γW2 (fl=Lee side Mooring force) with Hi/gT2 for d/W varying from 0.082 to 0.276 and also variation of fs/γW2 and fl/γW2 with W/L for Hi/d varying from 0.06 to 0.400.

  9. Biotic origin for Mima mounds supported by numerical modeling

    NASA Astrophysics Data System (ADS)

    Gabet, Emmanuel J.; Perron, J. Taylor; Johnson, Donald L.

    2014-02-01

    Mima mounds are ~ 1-m-high hillocks found on every continent except Antarctica. Despite often numbering in the millions within a single field, their origin has been a mystery, with proposed explanations ranging from glacial processes to seismic shaking. One hypothesis proposes that mounds in North America are built by burrowing mammals to provide refuge from seasonally saturated soils. We test this hypothesis with a numerical model, parameterized with measurements of soil transport by gophers from a California mound field, that couples animal behavior with geomorphic processes. The model successfully simulates the development of the mounds as well as key details such as the creation of vernal pools, small intermound basins that provide habitat for endemic species. Furthermore, we demonstrate that the spatial structure of the modeled mound fields is similar to actual mound fields and provides an example of self-organized topographic features. We conclude that, scaled by body mass, Mima mounds are the largest structures built by nonhuman mammals and may provide a rare example of an evolutionary coupling between landforms and the organisms that create them.

  10. Biotic Origin for Mima Mounds Supported by Numerical Model

    NASA Astrophysics Data System (ADS)

    Gabet, E. J.; Perron, J.; Johnson, D. L.

    2013-12-01

    Mima mounds are ~1-m-high hillocks found on every continent except Antarctica. Despite often numbering in the millions within a single field, their origin has been a mystery, with proposed explanations ranging from glacial processes to seismic shaking. One hypothesis proposes that mounds in North America are built by burrowing mammals to provide refuge from seasonally saturated soils. We test this hypothesis with a numerical model, parameterized with measurements of soil transport by gophers from a California mound field, that couples animal behavior with geomorphic processes. The model successfully simulates the development of the mounds, as well as key details such as the creation of vernal pools, small intermound basins that provide habitat for endemic species. Furthermore, we demonstrate that the spatial structure of the modeled mound fields is similar to actual mound fields and provides an example of self-organized topographic features. We conclude that, scaled by body mass, Mima mounds are the largest structures built by non-human mammals, and may provide a rare example of an evolutionary coupling between landforms and the organisms that create them.

  11. Geochemical Arrays at Woolsey Mound Seafloor Observatory

    NASA Astrophysics Data System (ADS)

    Sleeper, K.; Wilson, R. M.; Chanton, J.; Lapham, L.; Farr, N.; Camilli, R.; Martens, C. S.; Pontbriand, C.

    2011-12-01

    A suite of geochemical monitoring arrays has been developed for the Woolsey Mound Seafloor Observatory in the northern Gulf of Mexico to evaluate the oceanographic and tectonic forcing factors on the formation and stability of gas hydrates. These arrays are designed to collect sustained, time-series data of chemical concentrations, gradients and fluxes from the subsurface to the seafloor and into the near bottom water column. A Pore Fluid Array provides time-series measurements of methane, sulfate and salinity in subsurface pore waters to evaluate microbial activity, hydrate formation and/or hydrate dissociation. A Chimney Sampler Array collects in situ chemical and physical readings at the benthic boundary. The array is designed around a vertical cylinder with a known volume and washout rate for measuring chemical gradients and flux at the seafloor. The Benthic Boundary Layer Array extends into the water column with a package of sensors in a node close to the seafloor and a similar node 20 m above the seafloor to evaluate upward, downward and transversely advecting fluids. The three arrays can be used in concert to evaluate a release of methane by the dissociation of gas hydrates: the Pore Fluid Array identifies the breakdown of gas hydrates in the subsurface, the Chimney Array determines the rate of flux at the seafloor and the Benthic Boundary Layer Array evaluates the fate of the release in the water column. Combining the data from the geochemical arrays with output from the geophysical arrays provides key information to evaluate the specific and relative importance of tectonic and oceanographic triggers for hydrate dissociation. New probes and deployment platforms have been developed for the installation and maintenance of the arrays and new systems are in place and under development for the recovery of the data. Generally, the complete array or its components have to be recovered to download the data. However, this summer 2011, a new optic modem system was

  12. Burial, mounding key at Isle of Purbeck

    SciTech Connect

    Reed, C.G. )

    1989-07-17

    Design and installation of LPG storage for BP Petroleum Development Ltd.'s Wytch Farm Project on the Isle of Purbeck was guided by the central need to obscure the storage site from view and preserve the natural beauty of the island. The Wytch Farm oil field development is an expansion project aimed at increasing crude-oil production from 5,500 b/d to 60,000 b/d. The oil field is located beneath the southern shores of Poole Harbour on the south coast of the U.K. in an area of outstanding beauty and adjacent to sites of special scientific interest. The article is divided into the following areas: Storage needs; Mounding concrete; Pressure resistance; Fracture, cracking concerns; Coating criteria; Cleaning, application; Sand bed foundations; Earthworks, Preparation installation; Settlement monitoring.

  13. Integrated study of Mississippian Lodgepole Waulsortian Mounds, Williston Basin, USA

    SciTech Connect

    Kupecz, J.A.; Arestad, J.F.; Blott, J. E.

    1996-06-01

    Waulsortian-type carbonate buildups in the Mississippian Lodgepole Formation, Williston Basin, constitute prolific oil reservoirs. Since the initial discovery in 1993, five fields have been discovered: Dickinson Field (Lodgepole pool); Eland Field; Duck Creek Field, Versippi Field; and Hiline Field. Cumulative production (October, 1995) is 2.32 million barrels of oil and 1.34 BCF gas, with only 69,000 barrels of water. Oil gravity ranges from 41.4 to 45.3 API. Both subsurface cores from these fields as well as outcrop (Bridget Range, Big Snowy and Little Belt Mountains, Montana) are composed of facies representing deposition in mound, reworked mound, distal reworked mound, proximal flank, distal flank, and intermound settings. Porosity values within the mound and reworked mound facies are up to 15%; permeability values (in places fracture-enhanced) are up to tens of Darcies. Geometries of the mounds are variable. Mound thicknesses in the subsurface range from approximately 130-325 feet (40-100 meters); in outcrop thicknesses range from less than 30 ft (9 m) to over 250 ft (76 m). Subsurface areal dimensions range from approximately 0.5 x 1.0 mi (0.8 x 1.6 km) to 3.5 x 5.5 mi (5.6 x 8.8 km). Integration of seismic data with core and well-log models sheds light on the exploration for Lodgepole mounds. Seismic modeling of productive mounds in the Dickinson and Eland fields identifies characteristics useful for exploration, such as local thickening of the Lodgepole to Three Forks interval. These observations are confirmed in reprocessed seismic data across Eland field and on regional seismic data. Importantly, amplitude versus offset modeling identifies problems with directly detecting and identifying porosity within these features with amplitude analyses. In contrast, multicomponent seismic data has great potential for imaging these features and quantifying porous zones within them.

  14. In Operando GISAXS Studies of Mound Coarsening in Electrochemical Homoepitaxy

    NASA Astrophysics Data System (ADS)

    Ruge, Martin; Golks, Frederik; Zegenhagen, Jörg; Magnussen, Olaf M.; Stettner, Jochim

    2014-02-01

    Kinetic roughening during electrodeposition was studied by grazing incidence small angle x-ray scattering for the case of Au(001) homoepitaxial growth in Cl- containing electrolytes. The formation and coarsening of an isotropic mound distribution on unreconstructed Au(001) and of [110]-oriented anisotropic mounds on the "hex" reconstructed surface was observed. The lateral mound coarsening is described by a well-defined scaling law. On unreconstructed Au a transition in the coarsening exponent from ≈1/4 to ≈1/3 with increasing potential is found, which can be explained by the pronounced potential dependence of surface transport processes in an electrochemical environment.

  15. In operando GISAXS studies of mound coarsening in electrochemical homoepitaxy.

    PubMed

    Ruge, Martin; Golks, Frederik; Zegenhagen, Jörg; Magnussen, Olaf M; Stettner, Jochim

    2014-02-01

    Kinetic roughening during electrodeposition was studied by grazing incidence small angle x-ray scattering for the case of Au(001) homoepitaxial growth in Cl- containing electrolytes. The formation and coarsening of an isotropic mound distribution on unreconstructed Au(001) and of [110]-oriented anisotropic mounds on the "hex" reconstructed surface was observed. The lateral mound coarsening is described by a well-defined scaling law. On unreconstructed Au a transition in the coarsening exponent from ≈1/4 to ≈1/3 with increasing potential is found, which can be explained by the pronounced potential dependence of surface transport processes in an electrochemical environment. PMID:24580610

  16. Fractal-mound growth of pentacene thin films

    NASA Astrophysics Data System (ADS)

    Zorba, Serkan; Shapir, Yonathan; Gao, Yongli

    2006-12-01

    The growth mechanism of pentacene film formation on SiO2 substrate was investigated with a combination of atomic force microscopy measurements and numerical modeling. In addition to the diffusion-limited aggregation (DLA) that has already been shown to govern the growth of the ordered pentacene thin films, it is shown here that the Schwoebel barrier effect steps in and disrupts the desired epitaxial growth for the subsequent layers, leading to mound growth. The terraces of the growing mounds have a fractal dimension of 1.6, indicating a lateral DLA shape. This growth morphology thus combines horizontal DLA-like growth with vertical mound growth.

  17. Geotechnical characteristics of shallow ocean dredge spoil disposal mounds

    SciTech Connect

    Demars, K.R.; Dowling, J.J.; Long, R.P.; Morton, R.W.

    1984-05-01

    This paper summarizes the data obtained from site surveying and sediment sampling of dredge spoil disposal mounds at the Central Long Island Sound site. Emphasis is placed on the geotechnical and geological features of the mound and natural seabed. Since some of the spoil is contaminated, cappings of clean spoil have been used to isolate the spoil mounds from fauna and flora in the water column. Because of the contaminated spoil, improvements in the disposal techniques are needed and methodologies must be developed for evaluating short-term and long-term stability of these shallow ocean deposits which are subjected to loadings from waves, spoil disposal and capping operations.

  18. Origin of the Mima Mounds, Thurston County region, Washington

    USGS Publications Warehouse

    Newcomb, R.C.

    1952-01-01

    There has been recent favorable consideration of the idea that the Mima mounds were made by gophers. The writer believes the evidence indicates that gophers function only in the reworking of the mound material, not in the primary construction. The plausibility of the earlier glacial or periglacial theory has been increased by recent knowledge of permafrost and of the deposits made by combined water and ice in cold climates. The gopher theory, as it has been applied to the Mima mounds, contains internal disharmonies and ignores significant field evidence supporting the earlier idea.

  19. Biodiversity and ecological composition of macrobenthos on cold-water coral mounds and adjacent off-mound habitat in the bathyal Porcupine Seabight, NE Atlantic

    NASA Astrophysics Data System (ADS)

    Henry, Lea-Anne; Roberts, J. Murray

    2007-04-01

    The cold-water scleractinian corals Lophelia pertusa and Madrepora oculata form mound structures on the continental shelf and slope in the NE Atlantic. This study is the first to compare the taxonomic biodiversity and ecological composition of the macrobenthos between on- and off-mound habitats. Seven box cores from the summits of three mounds and four cores from an adjacent off-mound area in the Belgica Mound Province in the Porcupine Seabight yielded 349 species, including 10 undescribed species. On-mound habitat was three times more speciose, and was richer with higher evenness and significantly greater Shannon's diversity than off-mound. Species composition differed significantly between habitats and the four best discriminating species were Pliobothrus symmetricus (more frequent off-mound), Crisia nov. sp, Aphrocallistes bocagei and Lophelia pertusa (all more frequent on-mound). Filter/suspension feeders were significantly more abundant on-mound, while deposit feeders were significantly more abundant off-mound. Species composition did not significantly differ between mounds, but similarity within replicates decreased from Galway MoundMound. We propose that, despite having greater vertical habitat heterogeneity that supports higher biodiversity, coral mounds have a characteristic "reef fauna" linked to species' biology that contrasts with the higher horizontal habitat heterogeneity conferred by the action of deposit feeders and a varied seabed sedimentary facies off-mound. Standardisation of equipment and restriction of analyses to higher taxonomic levels would facilitate prospective comparative analyses of cold-water coral biodiversity across larger spatio-temporal scales.

  20. VIEW LOOKING NORTHEAST AT EARTH MOUND. NOTE THE RECTANGULAR OPENINGS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW LOOKING NORTHEAST AT EARTH MOUND. NOTE THE RECTANGULAR OPENINGS USED FOR OBSERVATION EQUIPMENT AND PERISCOPE TOPS. - Marshall Space Flight Center, Redstone Rocket (Missile) Test Stand, Dodd Road, Huntsville, Madison County, AL

  1. 1. Perspective view southwest of filtration bed with earth mounded ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Perspective view southwest of filtration bed with earth mounded over facility. Armory Street appears in the foreground. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  2. Evolution of Mound Morphology in Reversible Homoepitaxy on Cu(100)

    SciTech Connect

    Zuo, J.; Wendelken, J.

    1997-04-01

    Evolution of mound morphology in reversible homoepitaxy on Cu(100) was studied via spot-profile-analysis (SPA) LEED and scanning tunneling microscopy. The mound separation shows coarsening vs growth time with L(t){approximately}t{sup 1/4}, in support of theory based on capillarity between mounds. The growth ultimately reaches a steady state characterized by a selected mound angle of {approximately}5.6{degree}. We suggest that this results from a downhill current driven by step edge line tension in balance with an uphill current due to the Schwoebel barrier effect. Also, we have clarified the interpretation for the evolution of the SPA-LEED profile from a ring structure to a single time-invariant peak. {copyright} {ital 1997} {ital The American Physical Society}

  3. 2. CONCRETE PADDING AREA BETWEEN BERM MOUNDS, LOOKING NORTH FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. CONCRETE PADDING AREA BETWEEN BERM MOUNDS, LOOKING NORTH FROM TOP OF BERM. - NIKE Missile Base C-84, Acid Fueling Station, North of Launch Area Entrance Drive, eastern central portion of base, Barrington, Cook County, IL

  4. Audit of Mound Plant`s reduction in force

    SciTech Connect

    Not Available

    1993-05-17

    Objective of this audit was to determine whether the Mound Plant`s Fiscal Year 1992 reduction in force (RIF) was effectively managed and implemented properly by DOE. DOE established policy to encourage contractors to reduce staffing by voluntary separations without unreasonable separation costs. EG&G Mound`s FY 1992 RIF was accomplished by voluntary separations; however, its implementation unreasonably increased costs because DOE did not have adequate criteria or guidelines for evaluating contractors` RIF proposals, and because EG&G Mound furnished inaccurate cost data to DOE evaluators. The unreasonable costs amounted to at least $21 million. Recommendations are made that DOE develop and implement guidelines to impose limitations on voluntary separation allowances, early retirement incentive payments, and inclusion of crucial employee classifications in voluntary RIFs.

  5. Simulation of Groundwater Mounding Beneath Hypothetical Stormwater Infiltration Basins

    USGS Publications Warehouse

    Carleton, Glen B.

    2010-01-01

    Groundwater mounding occurs beneath stormwater management structures designed to infiltrate stormwater runoff. Concentrating recharge in a small area can cause groundwater mounding that affects the basements of nearby homes and other structures. Methods for quantitatively predicting the height and extent of groundwater mounding beneath and near stormwater Finite-difference groundwater-flow simulations of infiltration from hypothetical stormwater infiltration structures (which are typically constructed as basins or dry wells) were done for 10-acre and 1-acre developments. Aquifer and stormwater-runoff characteristics in the model were changed to determine which factors are most likely to have the greatest effect on simulating the maximum height and maximum extent of groundwater mounding. Aquifer characteristics that were changed include soil permeability, aquifer thickness, and specific yield. Stormwater-runoff variables that were changed include magnitude of design storm, percentage of impervious area, infiltration-structure depth (maximum depth of standing water), and infiltration-basin shape. Values used for all variables are representative of typical physical conditions and stormwater management designs in New Jersey but do not include all possible values. Results are considered to be a representative, but not all-inclusive, subset of likely results. Maximum heights of simulated groundwater mounds beneath stormwater infiltration structures are the most sensitive to (show the greatest change with changes to) soil permeability. The maximum height of the groundwater mound is higher when values of soil permeability, aquifer thickness, or specific yield are decreased or when basin depth is increased or the basin shape is square (and values of other variables are held constant). Changing soil permeability, aquifer thickness, specific yield, infiltration-structure depth, or infiltration-structure shape does not change the volume of water infiltrated, it changes the

  6. Environmental assessment for commercialization of the Mound Plant

    SciTech Connect

    Not Available

    1994-10-26

    In November 1993 US DOE decided to phase out operations at the Mound Plant in Miamisburg, Ohio, with the goal of releasing the site for commercial use. The broad concept is to transform the plant into an advanced manufacturing center with the main focus on commercializing products and other technology. DOE proposes to lease portions of the Mound Plant to commercial enterprises. This Environmental Impact statement has a finding of no significant impact in reference to such action.

  7. Integrated and holistic suitability assessment of recycling options for masonry rubble

    NASA Astrophysics Data System (ADS)

    Herbst, T.; Rübner, K.; Meng, B.

    2012-04-01

    Our industrial society depends on continuous mining and consumption of raw materials and energy. Besides, the building sector causes one of the largest material streams in Germany. On the one hand, the building sector is connected with a high need in material and energetic resources as well as financial expenditures. On the other hand, nearly 50 % of the volume of waste arises from the building industry. During the last years, the limitation of natural resources, increasing negative environmental consequences as well as rising prices and shortages of dump space have led to a change in thinking in the building and waste industry to a closed substance cycle waste management. In consideration of the production figures of the main kinds of masonry units (clay bricks, sand-lime bricks, autoclaved aerated concrete brick, concrete blocks), a not unimportant quantity of masonry rubble (including gypsum plaster boards, renders, mortars and mineral insulating materials) of more than 20 million tons per year is generated in the medium term. With regard to a sustainable closed substance cycle waste management, these rest masses have to be recycled if possible. Processed aggregates made from masonry rubble can be recycled in the production of new masonry units under certain conditions. Even carefully deconstructed masonry units can once more re-used as masonry units, particularly in the area of the preservation of monuments and historical buildings. In addition, masonry rubble in different processing qualities is applied in earth and road construction, horticulture and scenery construction as well as concrete production. The choice of the most suitable recycling option causes technical, economical and ecological questions. At present, a methodology for a comprehensive suitability assessment with a passable scope of work does not exist. Basic structured and structuring information on the recycling of masonry rubble is absent up to now. This as well as the economic and technical

  8. Termite mounds harness diurnal temperature oscillations for ventilation

    PubMed Central

    King, Hunter; Ocko, Samuel; Mahadevan, L.

    2015-01-01

    Many species of millimetric fungus-harvesting termites collectively build uninhabited, massive mound structures enclosing a network of broad tunnels that protrude from the ground meters above their subterranean nests. It is widely accepted that the purpose of these mounds is to give the colony a controlled microclimate in which to raise fungus and brood by managing heat, humidity, and respiratory gas exchange. Although different hypotheses such as steady and fluctuating external wind and internal metabolic heating have been proposed for ventilating the mound, the absence of direct in situ measurement of internal air flows has precluded a definitive mechanism for this critical physiological function. By measuring diurnal variations in flow through the surface conduits of the mounds of the species Odontotermes obesus, we show that a simple combination of geometry, heterogeneous thermal mass, and porosity allows the mounds to use diurnal ambient temperature oscillations for ventilation. In particular, the thin outer flutelike conduits heat up rapidly during the day relative to the deeper chimneys, pushing air up the flutes and down the chimney in a closed convection cell, with the converse situation at night. These cyclic flows in the mound flush out CO2 from the nest and ventilate the colony, in an unusual example of deriving useful work from thermal oscillations. PMID:26316023

  9. Termite mounds harness diurnal temperature oscillations for ventilation.

    PubMed

    King, Hunter; Ocko, Samuel; Mahadevan, L

    2015-09-15

    Many species of millimetric fungus-harvesting termites collectively build uninhabited, massive mound structures enclosing a network of broad tunnels that protrude from the ground meters above their subterranean nests. It is widely accepted that the purpose of these mounds is to give the colony a controlled microclimate in which to raise fungus and brood by managing heat, humidity, and respiratory gas exchange. Although different hypotheses such as steady and fluctuating external wind and internal metabolic heating have been proposed for ventilating the mound, the absence of direct in situ measurement of internal air flows has precluded a definitive mechanism for this critical physiological function. By measuring diurnal variations in flow through the surface conduits of the mounds of the species Odontotermes obesus, we show that a simple combination of geometry, heterogeneous thermal mass, and porosity allows the mounds to use diurnal ambient temperature oscillations for ventilation. In particular, the thin outer flutelike conduits heat up rapidly during the day relative to the deeper chimneys, pushing air up the flutes and down the chimney in a closed convection cell, with the converse situation at night. These cyclic flows in the mound flush out CO2 from the nest and ventilate the colony, in an unusual example of deriving useful work from thermal oscillations. PMID:26316023

  10. Food preferences and mound-building behaviour of the mound-building mice Mus spicilegus.

    PubMed

    Hölzl, Michaela; Krištofík, Ján; Darolová, Alžbeta; Hoi, Herbert

    2011-10-01

    Optimal foraging strategies and food choice are influenced by various factors, e.g. availability, size and caloric content of the food type and predation risk. However, food choice criteria may change when food is not eaten immediately but has to be carried to a storage site for later use. For example, handling time in terms of harvesting and transport time should be optimized, particularly when the risk of predation is high. Thus, it is not clear whether food selected by hoarding animals reflects their food preference due to intrinsic features of the food type, e.g. size, caloric or lipid content, or whether the food type selected is a compromise that also considers the handling time required for harvesting and transport. We investigate this question in relation to food hoarding behaviour in mound-building mice. In autumn, mound-building mice Mus spicilegus collect seeds and other plant material and cover it with soil. Such above-ground storage is quite unusual for rodents. Here, we investigated whether there is a relationship between the seed species preferred as building materials and those preferred for food. We conducted a seed preference test using three most collected weed species for mound building. Controlling factors like food availability or predation risk, mice prefer Setaria spp. as food, although Amaranthus spp. and Chenopodium spp. were preferentially harvested and stored. By including the availability of the three species, our experimental results were confirmed, namely, a clear preference for Setaria spp. Also, handling time and seed size revealed to influence plant choice. PMID:21861181

  11. Food preferences and mound-building behaviour of the mound-building mice Mus spicilegus

    NASA Astrophysics Data System (ADS)

    Hölzl, Michaela; Krištofík, Ján; Darolová, Alžbeta; Hoi, Herbert

    2011-10-01

    Optimal foraging strategies and food choice are influenced by various factors, e.g. availability, size and caloric content of the food type and predation risk. However, food choice criteria may change when food is not eaten immediately but has to be carried to a storage site for later use. For example, handling time in terms of harvesting and transport time should be optimized, particularly when the risk of predation is high. Thus, it is not clear whether food selected by hoarding animals reflects their food preference due to intrinsic features of the food type, e.g. size, caloric or lipid content, or whether the food type selected is a compromise that also considers the handling time required for harvesting and transport. We investigate this question in relation to food hoarding behaviour in mound-building mice. In autumn, mound-building mice Mus spicilegus collect seeds and other plant material and cover it with soil. Such above-ground storage is quite unusual for rodents. Here, we investigated whether there is a relationship between the seed species preferred as building materials and those preferred for food. We conducted a seed preference test using three most collected weed species for mound building. Controlling factors like food availability or predation risk, mice prefer Setaria spp. as food, although Amaranthus spp. and Chenopodium spp. were preferentially harvested and stored. By including the availability of the three species, our experimental results were confirmed, namely, a clear preference for Setaria spp. Also, handling time and seed size revealed to influence plant choice.

  12. Facies architecture and diagenesis of Belgian Late Frasnian carbonate mounds

    NASA Astrophysics Data System (ADS)

    Boulvain, Frédéric

    2001-12-01

    Late Frasnian Petit-Mont Member carbonate mounds occur in the southern part of the Dinant Synclinorium and in the Philippeville Anticline (SW Belgium). These mounds are 30 to 80 m thick and 100 to 250 m in diameter. They are embedded in shale, nodular shale and argillaceous limestone. Based on facies mapping of 14 buildups and related off-mound sediments, these mounds typically started from below the photic and storm wave base zones and builtup into shallow water environments. Above an argillaceous limestone substrate, the first carbonate mound facies consists of spiculitic wackestone with stromatactis (PM1), which becomes progressively enriched in crinoids and corals (PM2), then in peloids, stromatoporoids and cyanobacteria (PM3). PM4 consists of algal-coral-peloid wackestone and packstone with green algae and thick algal coatings. A core of algal and microbial bindstone (PM5) sporadically occurs within large mounds. The uppermost part of these mounds may show a recurrence of facies PM2 and PM1. PM1 to PM3 are coloured red by hematite derived from microaerophilic iron bacteria; PM4 and PM5 are grey. The transition from the aphotic to the cyanobacterial photic zone is recorded in the succession PM2-PM3; the transition from the cyanobacterial to the green algal photic zone is recorded by PM3-PM5. Storm wave base was reached within PM3 and fair-weather wave base within PM5. This paleobathymetric interpretation suggests a depth of 100-150 m during initial establishment of PM1. Three types of mounds can be distinguished on the basis of geometry and facies architecture: (1) "Les Bulants"-type mounds display a continuous vertical facies succession (PM2-3-4-5) and low relief; (2) although exhibiting the same facies succession as "Les Bulants", "Les Wayons"-type mounds show a distinct relief with steep flanks and bioclastic talus; (3) "St.-Rémy" mounds consist exclusively of PM1 and PM2, bioclastic flank deposits are not observed. From (1) to (3), these mound types

  13. Central Shops Burning/Rubble Pit 631-6G Additonal Sampling and Monitor Well Installation Report

    SciTech Connect

    Palmer, E.

    1995-02-01

    The Central Shops Burning/Rubble Pit 631-6G was constructed in 1951 as an unlined earthen pit in surficial sediments for disposal and incineration of potentially hazardous substances, such as metals and organic solvents.

  14. From Shell Midden to Midden-Mound: The Geoarchaeology of Mound Key, an Anthropogenic Island in Southwest Florida, USA

    PubMed Central

    Cherkinsky, Alexander; Roberts Thompson, Amanda D.; Walker, Karen J.; Newsom, Lee A.; Savarese, Michael

    2016-01-01

    Mound Key was once the capital of the Calusa Kingdom, a large Pre-Hispanic polity that controlled much of southern Florida. Mound Key, like other archaeological sites along the southwest Gulf Coast, is a large expanse of shell and other anthropogenic sediments. The challenges that these sites pose are largely due to the size and areal extent of the deposits, some of which begin up to a meter below and exceed nine meters above modern sea levels. Additionally, the complex depositional sequences at these sites present difficulties in determining their chronology. Here, we examine the development of Mound Key as an anthropogenic island through systematic coring of the deposits, excavations, and intensive radiocarbon dating. The resulting data, which include the reversals of radiocarbon dates from cores and dates from mound-top features, lend insight into the temporality of site formation. We use these insights to discuss the nature and scale of human activities that worked to form this large island in the context of its dynamic, environmental setting. We present the case that deposits within Mound Key’s central area accumulated through complex processes that represent a diversity of human action including midden accumulation and the redeposition of older sediments as mound fill. PMID:27123928

  15. From Shell Midden to Midden-Mound: The Geoarchaeology of Mound Key, an Anthropogenic Island in Southwest Florida, USA.

    PubMed

    Thompson, Victor D; Marquardt, William H; Cherkinsky, Alexander; Roberts Thompson, Amanda D; Walker, Karen J; Newsom, Lee A; Savarese, Michael

    2016-01-01

    Mound Key was once the capital of the Calusa Kingdom, a large Pre-Hispanic polity that controlled much of southern Florida. Mound Key, like other archaeological sites along the southwest Gulf Coast, is a large expanse of shell and other anthropogenic sediments. The challenges that these sites pose are largely due to the size and areal extent of the deposits, some of which begin up to a meter below and exceed nine meters above modern sea levels. Additionally, the complex depositional sequences at these sites present difficulties in determining their chronology. Here, we examine the development of Mound Key as an anthropogenic island through systematic coring of the deposits, excavations, and intensive radiocarbon dating. The resulting data, which include the reversals of radiocarbon dates from cores and dates from mound-top features, lend insight into the temporality of site formation. We use these insights to discuss the nature and scale of human activities that worked to form this large island in the context of its dynamic, environmental setting. We present the case that deposits within Mound Key's central area accumulated through complex processes that represent a diversity of human action including midden accumulation and the redeposition of older sediments as mound fill. PMID:27123928

  16. The strength of rubble-pile bodies: Theory, observations, and predictions

    NASA Astrophysics Data System (ADS)

    Scheeres, D.; Sanchez, P.

    2014-07-01

    The strength and morphology of a rubble-pile body will control how fast it can rotate before shedding mass or deforming, influence the process by which multi-component asteroid systems are created, and could have significance for the mitigation of hazardous near-Earth asteroids (NEA) should this be necessary in the future [1,2,3]. The morphology of these bodies, including the size distribution of boulders and grains internal to the system, the macro-porosity of these bodies, and the shapes and spin states of these bodies, are important for understanding and interpreting spacecraft imaging of asteroids, for predicting the end-state evolution of these bodies, and for gaining insight into their formation circumstances. Despite these compelling issues and questions, real insight on the strength of rubble-pile bodies and their morphology remains elusive. We explore a theory recently developed by us [3] for the morphology and strength of a rubble-pile body based on the properties of cohesive powders and show that several observations of small asteroid properties are consistent with the predictions of this model. That small asteroids can be rubble-pile bodies is clear based on several lines of evidence, including spacecraft imaging and sample analysis of Itokawa [4,5], the existence of the rotation spin rate barrier for bodies larger than a few hundred meters [6], and the recent observations of disrupting asteroids in the main belt [7,8]. A simple extrapolation from these observations are that bodies of at least a few hundred meters and larger are composed of a size distribution of components that range from decameter-sized boulders down to micron-sized grains. The relevant questions then become what the characteristics of these size distributions are and what physical implications for the strength of these bodies arise from this morphology. Based on the theory of cohesive granular mechanics [9] combined with a thorough review of results from the Hayabusa mission [4

  17. [Relationships between mound size and captured ergate amount of Solenopsis invicta].

    PubMed

    Huang, Jun; Lu, Yong-Yue; Xu, Yi-Juan; Liang, Guang-Wen; Zeng, Ling

    2009-08-01

    By the method of bait trapping, this paper studied the relationships between mound size (mound volume and mound surface base area) and captured ergate amount of Solenopsis invicta in wasteland and greenbelt. In wasteland, with the increase of mound size, the amount of captured S. invicta ergates increased rapidly at first, slowed down then, and kept stable at last. When the mound volume and surface base area were 11634 cm3 and 1308 cm2 respectively, the captured ergate amount reached the maximum, being 291 individuals per trap. Similar patterns were observed in greenbelt. The increase of captured S. invicta ergate amount slowed down rapidly when the mound volume was larger than 18089 cm3, and reached the maximum (232 individual per trap) when the mound volume was 25974 cm3. The Weibull equation could better describe the relationships between the mound volume and mound surface base area and the captured ergate amount of S. invicta. PMID:19947223

  18. Microbial composition of biofilms associated with lithifying rubble of Acropora palmata branches.

    PubMed

    Beltrán, Yislem; Cerqueda-García, Daniel; Taş, Neslihan; Thomé, Patricia E; Iglesias-Prieto, Roberto; Falcón, Luisa I

    2016-01-01

    Coral reefs are among the most productive ecosystems on the planet, but are rapidly declining due to global-warming-mediated changes in the oceans. Particularly for the Caribbean region, Acropora sp. stony corals have lost ∼80% of their original coverage, resulting in vast extensions of dead coral rubble. We analyzed the microbial composition of biofilms that colonize and lithify dead Acropora palmata rubble in the Mexican Caribbean and identified the microbial assemblages that can persist under scenarios of global change, including high temperature and low pH. Lithifying biofilms have a mineral composition that includes aragonite and magnesium calcite (16 mole% MgCO(3)) and calcite, while the mineral phase corresponding to coral skeleton is basically aragonite. Microbial composition of the lithifying biofilms are different in comparison to surrounding biotopes, including a microbial mat, water column, sediments and live A. palmata microbiome. Significant shifts in biofilm composition were detected in samples incubated in mesocosms. The combined effect of low pH and increased temperature showed a strong effect after two-week incubations for biofilm composition. Findings suggest that lithifying biofilms could remain as a secondary structure on reef rubble possibly impacting the functional role of coral reefs. PMID:26705570

  19. Controls on mound formation and effects of fluid ascent on the gas hydrate system of mound structures offshore Costa Rica

    NASA Astrophysics Data System (ADS)

    Planert, L.; Klaeschen, D.; Berndt, C.; Hensen, C.; Brueckmann, W.

    2010-12-01

    Our analysis of 2D MCS seismic data from the Middle America margin provides an insight into the buildup and formation mechanisms of mound structures and the effects of fluid ascent on the gas hydrate system observed on the continental slope offshore Costa Rica. Our targets, Mounds 11&12, are the sites of IODP drilling proposal 633-Full2, which aims to enhance the general understanding of complex forearc dewatering processes of the erosive subduction system off Costa Rica. Major sites of dewatering planned for drilling are mounds, related to mud diapirism/volcanism and precipitation of authigenic carbonates, and large-scale slides related to the subduction of seamounts. Geochemical analysis of methane hydrate and chloride anomalies as well as heat flow modeling of the mounds indicate deeply sourced fluids discharged by clay dehydration at the decollement. Hence, the hydrogeological system at this margin appears to be dominated by the fracture porosity of faults which extend through the overriding plate and provide the paths for fluids liberated by early dehydration reactions from the plate boundary. In order to test the hypothesis of deeply sourced and fault-controlled dewatering sites and to better understand the interactions between gas hydrate formation and dissociation with the fluid ascent from the deep sources, new pre-site survey seismic profiles were acquired using the 36-gun, four-string linear gun array of R/V Marcus Langseth, and a 240 channel streamer with 3000 m of active length. The seismic lines were prestack depth migrated, in which the velocity model is iteratively improved using depth focusing analysis and residual moveout correction on common image point gathers. Improvement of the deep imaging involved multiple attenuation and detailed velocity analysis of the lower sedimentary portions and beneath the basement down to the plate boundary. Our results reveal an upward bending of the bottom simulating reflection (BSR) directly beneath the mounds

  20. Environmental monitoring at Mound: 1986 report

    SciTech Connect

    Carfagno, D.G.; Farmer, B.M.

    1987-05-11

    The local environment around Mound was monitored for tritium and plutonium-238. The results are reported for 1986. Environmental media analyzed included air, water, vegetation, foodstuffs, and sediment. The average concentrations of plutonium-238 and tritium were within the DOE interim air and water Derived Concentration Guides (DCG) for these radionuclides. The average incremental concentrations of plutonium-238 and tritium oxide in air measured at all offsite locations during 1986 were 0.03% and 0.01%, respectively, of the DOE DCGs for uncontrolled areas. The average incremental concentration of plutonium-238 measured at all locations in the Great Miami River during 1986 was 0.0005% of the DOE DCG. The average incremental concentration of tritium measured at all locations in the Great Miami River during 1986 was 0.005% of the DOE DCG. The average incremental concentrations of plutonium-238 found during 1986 in surface and area drinking water were less than 0.00006% of the DOE DCG. The average incremental concentration of tritium in surface water was less than 0.005% of the DOE DCG. All tritium in drinking water data is compared to the US EPA Drinking Water Standard. The average concentrations in local private and municipal drinking water systems were less than 25% and 1.5%, respectively. Although no DOE DCG is available for foodstuffs, the average concentrations are a small fraction of the water DCG (0.04%). The concentrations of sediment samples obtained at offsite surface water sampling locations were extremely low and therefore represent no adverse impact to the environment. The dose equivalent estimates for the average air, water, and foodstuff concentrations indicate that the levels are within 1% of the DOE standard of 100 mrem. None of these exceptions, however, had an adverse impact on the water quality of the Great Miami River or caused the river to exceed Ohio Stream Standards. 20 refs., 5 figs., 31 tabs.

  1. The Mounds of Cydonia - A Case Study for Planetary SETI

    NASA Astrophysics Data System (ADS)

    Crater, H. W.

    The Society for Planetary SETI Research (SPSR) has as its aim the study of features on planetary surfaces, to evaluate possible signs of ET activity in the form of landscape modifications or other alterations not easily attributable to natural geological formation. This paper displays one such study, based in part on a previous one which showed that a group of twelve mound-like formations in the Cydonia area of Mars, of relatively small and nearly uniform size, have relative positions that repeatedly display symmetries well beyond chance. It focuses primarily on five of those mounds, showing that they display some unusual and precise geometrical features highlighted by close connections to sequences of prime numbers. This paper also reviews the related statistical anomaly found in the relative placement of these mounds and discusses some recent critiques of that work. Previous work showed that the frequency of appearance of related right and isosceles triangles in the mound distribution cluster sharply in density about a certain value of the angle defining those related triangles. In order to assess the role of the special angle itself as a possible source in the sharp clustering in the density of appearances of these triangles, this paper reports a new statistical study that confirms the extent to which the favored and redundant geometry implied by that angle has a self-duplication property. It involves an examination of each of 1 million randomly generated sets of 12 mounds with the same analysis techniques used for the actual Cydonia mounds. It is found that this property can account for only a small portion of the statistical anomaly found in the earlier work. Proposed further work includes an examination of a clear distinction between the 5 and 12 mound configurations and its possible relation to mound shapes using recent MGS high resolution images. Finally a discussion is given of a repeated connection between the triangles that appear in the ideal geometry

  2. The Gale Crater Mound in a Regional Geologic Setting

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.; Korn, L. K.

    2012-01-01

    The Mars Science Laboratory Rover Curiosity is commencing a two-year investigation of Gale crater and Mt. Sharp, the crater s prominent central mound. Gale is a 155 km, late Noachian / early Hesperian impact crater located near the dichotomy boundary separating the southern highlands from the northern plains. The central mound is composed of layered sedimentary rock, with upper and lower mound units separated by a prominent erosional unconformity (Milliken et al., 2010). The lower mound is of particular interest, as it contains secondary minerals indicative of a striking shift from water-rich to water-poor conditions on early Mars. A key unknown in the history of Gale is the relationship between the sedimentary units in the mound and sedimentary sequences in the surrounding region. We employed orbital remote sensing data to determine if areas within a 1,000 km radius of Gale match the characteristics of sedimentary units in Mt. Sharp. Regions of interest were defined based on: the mound s inferred age (late Noachian to early Hesperian), altitude range (-4,600 m to +400 m), and THEMIS nighttime brightness (a proxy for thermal inertia). This combination of characteristics is matched by two extensive units, the late Noachian subdued cratered unit Npl2 and Noachian / Hesperian undivided material HNu (Greeley and Guest, 1987), located along the dichotomy. Geomorphic units have been mapped within the Gale mound by Thomson et al. (2011) based on albedo, layering and erosional characteristics. Using orbital CTX, MOC and HiRISE images we examined all areas within our regions of interest for analogous geomorphic units in the same altitude ranges as the corresponding units in Mt. Sharp. The most convincing geomorphic analogs to lower mound units, dominated by fine-scale layering and prominent yardangs, were located approximately 200 km northeast and southeast of Gale in late Noachian unit Npl2. The most convincing geomorphic analogs to upper mound layered units are located

  3. Detection of cohesive forces in the rubble-pile asteroid (29075) 1950 DA

    NASA Astrophysics Data System (ADS)

    Rozitis, Benjamin; MacLennan, Eric; Emery, Joshua P.

    2014-11-01

    The physical behavior of rubble-pile asteroids has traditionally been described using only gravitational and frictional forces within a granular material. Cohesive forces in the form of small van der Waals forces between constituent grains have recently been predicted to be important for small rubble-pile asteroids (less than 10 kilometers in size), and could potentially explain how small fast spinning asteroids remain intact. It is possible to infer the existence of cohesive forces within a rubble-pile asteroid by determining if it has insufficient self-gravity, dictated by its bulk density, to prevent rotational breakup by centrifugal forces. The kilometer-sized and potentially-hazardous asteroid (29075) 1950 DA is one of the largest known candidates for being held together by cohesive forces, as it has a rotation period of 2.1216 h that is just beyond the critical spin limit of 2.2 h estimated for a cohesionless asteroid. Using the Advanced Thermophysical Model (or ATPM), in combination with the radar shape model, WISE thermal-infrared data, and Yarkovsky orbital drift measurement, we determined the thermal inertia, bulk density, and cohesive strength of (29075) 1950 DA (Rozitis et al., 2014, Nature, 512, 174-176). The thermal inertia value is remarkably low at 24 +20/-14 SI units, which gives a corresponding bulk density of 1.7 ± 0.7 g/cm^3 in the Yarkovsky orbital drift analysis. This bulk density is typical of a rubble-pile asteroid, and a minimum cohesive strength of 64 +12/-20 Pa is therefore required to prevent surface mass shedding and structural failure by centrifugal forces. This strength is comparable to, though somewhat less than, the cohesive forces found between the grains of lunar regolith. Finally, as (29075) 1950 DA has a 1 in 19,800 chance of impacting the Earth in 2880, and has the potential to disrupt like main-belt comet P/2013 R3, it raises new implications for impact mitigation against fast spinning rubble-pile asteroids.

  4. Steady State Perched Groundwater Mounds on Thick Sublayers

    NASA Astrophysics Data System (ADS)

    Brock, Richard R.

    1982-04-01

    Perched mounds that develop beneath a strip recharge basin are considered using the potential theory for a saturated flow. The mounds are assumed to develop upon an aquitard or sublayer whose thickness is large enough so that the vertical velocity at the base of the mound does not vary with distance from the centerline of the basin. A finite difference technique was used to solve the potential theory, and 20 mound profiles were determined for K/KL = 10, 50, 100, 500 and R/K = 0.2, 0.35, 0.50, 0.65, 0.80. K/KL is the ratio of the permeabilities, and R is the recharge rate. These profiles are compared to those based on the approximate Dupuit-Forchheimer (DF) theory, and a criterion for the range of validity of the DF theory for predicting the maximum mount thickness H0 is derived. It is found that for a sufficiently large value of K/KL, which depends on R/K and the desired accuracy, the DF theory is adequate. For smaller values of K/KL the potential theory must be used. Equipotential lines and velocity distributions are presented for a typical case where the potential and DF mound profiles are quite different.

  5. HiRISE observations of fractured mounds: Possible Martian pingos

    NASA Astrophysics Data System (ADS)

    Dundas, Colin M.; Mellon, Michael T.; McEwen, Alfred S.; Lefort, Alexandra; Keszthelyi, Laszlo P.; Thomas, Nicolas

    2008-02-01

    Early images from the High Resolution Imaging Science Experiment (HiRISE) camera have revealed small fractured mounds in the Martian mid-latitudes. HiRISE resolves fractures on the mound surfaces, indicating uplift, and shows that the mound surface material resembles that of the surrounding landscape. Analysis of Mars Orbiter Camera (MOC) images shows that in Utopia Planitia the mounds lie almost exclusively between 35-45°N. This range coincides with the peak-abundance latitudes of several landforms attributed to ground water or ice, including gullies, and suggests a ground ice-related origin. The best terrestrial analogues for the observed mound morphology are pingos, although some differences are noted. The presence of uncollapsed pingos would indicate the presence of near-surface ground ice in the Martian mid-latitudes, at depths greater than the ~1 meter sampled by orbital spectrometers. Pingo formation may require near-surface liquid water, which is consistent with a shallow groundwater model for the origin of gullies.

  6. HiRISE observations of fractured mounds: Possible Martian pingos

    USGS Publications Warehouse

    Dundas, C.M.; Mellon, M.T.; McEwen, A.S.; Lefort, A.; Keszthelyi, L.P.; Thomas, N.

    2008-01-01

    Early images from the High Resolution Imaging Science Experiment (HiRISE) camera have revealed small fractured mounds in the Martian mid-latitudes. HiRISE resolves fractures on the mound surfaces, indicating uplift, and shows that the mound surface material resembles that of the surrounding landscape. Analysis of Mars Orbiter Camera (MOC) images shows that in Utopia Planitia the mounds lie almost exclusively between 35-45??N. This range coincides with the peak-abundance latitudes of several landforms attributed to ground water or ice, including gullies, and suggests a ground ice-related origin. The best terrestrial analogues for the observed mound morphology are pingos, although some differences are noted. The presence of uncollapsed. pingos would indicate the presence of near-surface ground ice in the Martian mid-latitudes, at depths greater than the ???1 meter sampled by orbital spectrometers. Pingo formation may require near-surface liquid water, which is consistent with a shallow groundwater model for the origin of gullies. Copyright 2008 by the American Geophysical Union.

  7. Numerical analyses of caisson breakwaters on soft foundations under wave cyclic loading

    NASA Astrophysics Data System (ADS)

    Wang, Yuan-zhan; Yan, Zhen; Wang, Yu-chi

    2016-03-01

    A caisson breakwater is built on soft foundations after replacing the upper soft layer with sand. This paper presents a dynamic finite element method to investigate the strength degradation and associated pore pressure development of the intercalated soft layer under wave cyclic loading. By combining the undrained shear strength with the empirical formula of overconsolidation clay produced by unloading and the development model of pore pressure, the dynamic degradation law that describes the undrained shear strength as a function of cycle number and stress level is derived. Based on the proposed dynamic degradation law and M-C yield criterion, a dynamic finite element method is numerically implemented to predict changes in undrained shear strength of the intercalated soft layer by using the general-purpose FEM software ABAQUS, and the accuracy of the method is verified. The effects of cycle number and amplitude of the wave force on the degradation of the undrained shear strength of the intercalated soft layer and the associated excess pore pressure response are investigated by analyzing an overall distribution and three typical sections underneath the breakwater. By comparing the undrained shear strength distributions obtained by the static method and the quasi-static method with the undrained shear strength distributions obtained by the dynamic finite element method in the three typical sections, the superiority of the dynamic finite element method in predicting changes in undrained shear strength is demonstrated.

  8. Wave pressure acting on V-shaped floating breakwater in random seas

    NASA Astrophysics Data System (ADS)

    Yu, Yang; Ding, Ning; Lin, Jie; Hou, Jiajia

    2015-12-01

    Wave pressure on the wet surface of a V-shaped floating breakwater in random seas is investigated. Considering the diffraction effect, the unit velocity potential caused by the single regular waves around the breakwater is solved using the finite-depth Green function and boundary element method, in which the Green function is solved by integral method. The Response-Amplitude Operator (RAO) of wave pressure is acquired according to the Longuet-Higgins' wave model and the linear Bernoulli equation. Furthermore, the wave pressure's response spectrum is calculated according to the wave spectrum by discretizing the frequency domain. The wave pressure's characteristic value corresponding to certain cumulative probability is determined according to the Rayleigh distribution of wave heights. The numerical results and field test results are compared, which indicates that the wave pressure calculated in random seas agrees with that of field measurements. It is found that the bigger angle between legs will cause the bigger pressure response, while the increase in leg length does not influence the pressure significantly. The pressure at the side of head sea is larger than that of back waves. When the incident wave angle changes from 0° to 90°, the pressure at the side of back waves decreases clearly, while at the side of head sea, the situation is more complicated and there seems no obvious tendency. The concentration of wave energy around low frequency (long wavelength) will induce bigger wave pressure, and more attention should be paid to this situation for the structure safety.

  9. Cell Sorting in the Mound Stage of Dictyostelium

    NASA Astrophysics Data System (ADS)

    Jiang, Yi; Levine, Herbert; Glazier, James

    1998-03-01

    In the mound stage of slime mold Dictyostelium discoideum, cells differentiated into two types: pre-stalk and pre-spore. Pre-stalk cells sort and form a tip at the apex of the mound of prespore cells. How this pattern forms is as yet unknown. A cellular level model allows us to simulate both differential cell adhesion and chemotaxis, two principle mechanisms for cell migration. Simulations show that with differential adhesion only, pre-stalk cells move to the surface of the mound but form no tip. With chemotaxis driven by an outgoing circular wave only, a tip forms but contains both pre-stalk and pre-spore cells. Only for a narrow range of relative strengths between differential adhesion and chemotaxis, can both mechanisms work in concert to form a tip which contains only pre-stalk cells. The simulations provide a method to determine the processes necessary for patterning and suggest a series of further experiments.

  10. Environmental survey preliminary report, Mound Plant, Miamisburg, Ohio

    SciTech Connect

    Not Available

    1987-03-01

    This report presents the preliminary findings from the first phase of the Environmental Survey of the United States Department of Energy (DOE) Mound Plant, conducted August 18 through 29, 1986. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with the Mound Plant. The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. The on-site phase of the Survey involves the review of existing site environmental data, observations of the operations carried on at the Mound Plant, and interviews with site personnel. The Survey found no environmental problems at the Mound Plant that represent an immediate threat to human life. The environmental problems identified at the Mound Plant by the Survey confirm that the site is confronted with a number of environmental problems which are by and large a legacy from past practices at a time when environmental problems were less well understood. Theses problems vary in terms of their magnitude and risk, as described in this report. Although the sampling and analysis performed by the Mound Plant Survey will assist in further identifying environmental problems at the site, a complete understanding of the significance of some of the environmental problems identified requires a level of study and characterization that is beyond the scope of the Survey. Actions currently under way or planned at the site, particularly the Phase II activities of the Comprehensive Environmental Analysis and Response Program (CEARP) as developed and implemented by the Albuquerque Operations Office, will contribute toward meeting this requirement. 85 refs., 24 figs., 20 tabs.

  11. Perennial mounds in Utopia Planitia: (HiRISE) Evidence of a Glacial Origin

    NASA Astrophysics Data System (ADS)

    Soare, R. J.; Osinski, G. R.; Thomson, L.

    2009-03-01

    Here, we use HiRISE and high-resolution MOC images to discuss sub-kilometer pingo-like mounds in Utopia Planita. The mounds show geological characteristics consistent with formation by glacial accumulation, and ablation by sublimation.

  12. Shallow water mud-mounds of the Early Devonian Buchan Group, East Gippsland, Australia

    NASA Astrophysics Data System (ADS)

    Tosolini, A.-M. P.; Wallace, M. W.; Gallagher, S. J.

    2012-12-01

    The Lower Devonian Rocky Camp Member of the Murrindal Limestone, Buchan Group of southeastern Australia consists of a series of carbonate mud-mounds and smaller lagoonal bioherms. The Rocky Camp mound is the best exposed of the mud-mounds and has many characteristics in common with Waulsortian (Carboniferous) mounds. Detailed paleoecological and sedimentological studies indicate that the mound initially accumulated in the photic zone, in contrast to most of the previously recorded mud-mounds. Five facies are present in the mud-mound: a Dasycladacean Wackestone Facies at the base of the mound represents a moderate energy, shallow water bank environment within the photic zone. A Crinioidal Wackestone Facies was deposited in a laterally equivalent foreslope setting. A Poriferan-Crinoidal Mudstone Facies developed in a quiet, deeper water, lee-side mound setting associated with a minor relative sea-level rise. A Stromatoporoid-Coralline Packstone Facies in the upper part of the mound deposited in a high-energy, fair-weather wave base, mound-front environment. The crest of the mound is represented by a Crinoidal-Receptaculitid Packstone Facies indicative of a moderate-energy mound-top environment in the photic zone, sheltered by the mound-front stromatoporoid-coral communities. A mound flank facies is present on the southern side of the mound and this consists of high-energy crinoidal grainstones. Mud-mound deposition was terminated by a transgression that deposited dark gray, fossil-poor marl of the overlying Taravale Formation. The Rocky Camp mound appears to have originated in shallow water photic zone conditions and grew into a high-energy environment, with the mound being eventually colonized by corals and stromatoporoids. The indications of a high-energy environment during later mound growth (growth form of colonial metazoans and grainstones of the flanking facies) suggest that the micrite in the mound was autochthonous and implies the presence of an energy

  13. Analysis of Subsidence Data for the Bryan Mound Site, Texas

    SciTech Connect

    Bauer, Stephen J.

    1999-07-01

    The elevation change data measured at the Bryan Mound Strategic Petroleum Reserve (SPR) site over the last 16+ years has been studied and a model utilized to project elevation changes into the future. The subsidence rate at Bryan Mound is low in comparison with other Strategic Petroleum Reserve sites and has decreased with time due to the maintenance of higher operating pressures and the normal decrease in creep closure rate of caverns with time. However, the subsidence at the site is projected to continue. A model was developed to project subsidence values 20 years into the future; no subsidence related issues are apparent from these projections.

  14. Native American Calendric Orientation at Town Creek Indian Mound

    NASA Astrophysics Data System (ADS)

    Tiede, V. R.

    2005-12-01

    Evidence is presented for a newly discovered set of interior solar alignments - the equinox and summer solstice meridian transits - at a prehistoric Native American structure in the Southeast United States. Because North Carolina's Town Creek Indian Mound is the only Mississippian temple-mound accurately reconstructed from overhead photo-mosaics, the site is uniquely suited for applying the techniques of astro-archaeology (G. S. Hawkins 1983). Implications of the new findings for interpreting Muskogean ethnographic literature as well as future archaeoastronomical research at other Southeastern sites (e.g., Ocmulgee National Monument Earth Lodge, Georgia) are discussed.

  15. The Gale Crater Mound in a Regional Geologic Setting: Mapping and Probing Surrounding Outcrops for Areas Akin to the Central Mound at Gale

    NASA Technical Reports Server (NTRS)

    Korn, Lisa; Allen, Carlton

    2013-01-01

    There are several hypotheses on the origin of Gale Crater s central mound. These include ground water upwelling [1], aeolian, ice, volcanic [1-3], lacustrine [1-3], hydrothermal [1-3], and polar deposits [2]. The Mars Science Laboratory rover, Curiosity, landed in Gale Crater on August 6, 2012. It is currently analyzing samples along its traverse towards a channel and layered deposits that will provide insight into the sedimentary history of the crater [4]. Located at 5S, 138E, Gale is a 155km diameter, Late Noachian/Early Hesperian crater. It is situated along the southern highlands/northern lowlands dichotomy boundary and contains a central mound that rises approximately 5km from the crater floor [1]. The highest parts of Mt. Sharp are higher than the northern rim, but are roughly the same height as the southern rim. Mt. Sharp is divided into an upper mound and a lower mound, which are separated by an erosional unconformity [2]. The lower mound s sequences span the Late Noachian/Early Hesperian Epoch [1], while the upper mound s age is poorly constrained. The lower mound s sequences feature parallel beds of varying thickness, albedo, texture, and dip angle that are eroded into channels and yardangs [2]. The upper mound has finer layers at higher angles [1] with yardangs, serrated erosional patterns, and lobate features [3]. The lower mound also exhibits an upward progression of phyllosilicate to sulfate rich sediments, contrasting the upper mound s lack of hydrated minerals [4].

  16. Radiocarbon dating of large termite mounds of the miombo woodland of Katanga, DR Congo

    NASA Astrophysics Data System (ADS)

    Erens, Hans; Boudin, Mathieu; Mees, Florias; Dumon, Mathijs; Mujinya, Basile; Van Strydonck, Mark; Baert, Geert; Boeckx, Pascal; Van Ranst, Eric

    2015-04-01

    The miombo woodlands of South Katanga (D.R. Congo) are characterized by a high spatial density of large conic termite mounds built by Macrotermes falciger (3 to 5 ha-1, ~5 m high, ~15 m in diameter). The time it takes for these mounds to attain this size is still largely unknown. In this study, the age of four of these mounds is determined by 14C-dating the acid-insoluble organic carbon fraction of samples taken along the central vertical axis of two active and two abandoned mounds. The age sequence in the active mounds is erratic, but the results for the abandoned mounds show a logical increase of 14C-age with depth. The ages measured at 50 cm above ground level were 2335 - 2119 cal yr BP for the large abandoned mound (630 cm high), and 796 - 684 cal yr BP for the small abandoned mound (320 cm high). Cold-water-extractable organic carbon (CWEOC) measurements combined with spectroscopic analysis revealed that the lower parts of the active mounds may have been contaminated with recent carbon that leached from the active nest. Nonetheless, this method appears to provide reliable age estimates of large, abandoned termite mounds, which are older than previously estimated. Furthermore, historical mound growth rates seem to correspond to past temperature changes, suggesting a relation between past environmental conditions and mound occupancy. Keywords : 14C, water-extractable carbon, low-temperature combustion

  17. A coral-rubble ridge as evidence for hurricane overwash, Anegada (British Virgin Islands)

    NASA Astrophysics Data System (ADS)

    Spiske, M.; Halley, R. B.

    2014-01-01

    A coral-rubble ridge fringes part of the north shore of Anegada, a low-lying island in the northern Caribbean. Both historical reports and the geological record underline its vulnerability to tsunami and hurricanes. In this study we document the sedimentary characteristics of a coral-rubble ridge, which extends discontinuously along 1.5-1.8 km of chiefly north-facing shores at Soldier Wash. The ridge is less distinctive and appears only in patches along the west-facing shoreline at Windless Bight, where the wave regime is calmer. It is located ca. 8 m from the fair-weather shore, has a maximum width of 15 m and a maximum thickness of 0.8 m. The lower seaward-facing slope of the ridge is relatively flat, probably due to successive reworking, whereas the upper seaward slope is steep and partly displays avalanching faces. The landward flank is gently sloping and terminates abruptly. The ridge is mainly composed of well-rounded, encrusted and bored coral rubble (average diameter of 16 cm) that has been reworked in the shallow marine environment prior to transport. Only a few pieces of angular beach rock and karstified Pleistocene limestone are incorporated. The components build a clast-supported framework. No sand is present in the interstices. Imbrication of flat clasts indicates a deposition during landward bed load transport. The ridge morphology, composition and related hydrodynamic conditions during its emplacement are typical for coral-rubble ridges deposited by hurricane-induced storm surges. In comparison, nearby evidence for tsunami inundation is very different because the tsunami-transported coral boulders on Anegada are much bigger (2 m) than the biggest components in the ridge, they are deposited much farther inland (up to 1.5 km), and the corals seem to have been freshly broken out of the reef by the tsunami. The age of the ridge is difficult to estimate. The dark grey surface of the ridge is caused by bioweathering by endolithic organisms that takes tens

  18. A new approach to modelling impacts on rubble pile asteroid simulants

    NASA Astrophysics Data System (ADS)

    Deller, J. F.; Lowry, S. C.; Snodgrass, C.; Price, M. C.; Sierks, H.

    2016-02-01

    Many asteroids with low bulk densities must have a rubble pile structure and internal voids. Although little is known about their internal structure, numerical simulations of impact events on these asteroids rely on assumptions on how the voids are distributed. We present a new approach to model impacts on rubble pile asteroids that explicitly takes into account their internal structure. The formation of the asteroid is modelled as a rubble pile aggregate of spherical pebbles of different sizes. This aggregate is then converted into a high-resolution smoothed particle hydrodynamics (SPH) model, accounting for macroporosity inside the pebbles. We compare impact-event outcomes for a large set of internal configurations to explore the parameter space of our model-building process. The analysis of the fragment size distribution and the disruption threshold quantifies the specific influence of each input parameter. The size distribution of the pebbles used in our model is a simple power law, containing three free parameters: the slope α, the lower cut-off radius rmin and the upper cut-off radius rmax. The influence of all three parameters on the outcome is assessed in this paper. The existence of void space in our model increases the resistance against collisional disruption, a behaviour previously reported based on numerical simulations using a continuum description of porous material (Holsapple 2009). We show, for a set of asteroid collisions typical for small asteroids in the main belt, that no a priori knowledge of the exact size distribution of the pebbles inside the asteroid is needed, as the choice of the corresponding parameters does not directly correlate with the impact outcome.

  19. A Geophysical Laboratory for Rubble Pile Asteroids: The BASiX Mission

    NASA Astrophysics Data System (ADS)

    Scheeres, Daniel J.; Chesley, Steven; Anderson, Robert C.

    2014-11-01

    Small rubble pile asteroids exhibit a diverse range of evolutionary behaviors and morphologies, driven by an array of poorly understood geophysical effects. The complex ways that these bodies evolve belies their simple structure: gravitational aggregates of shattered primitive bodies. Their evolution can be dramatic, such as seen in the active asteroids P/2013 P5 and P/2013 R3, or may be subtly masked, such as in the tide-BYORP equilibria of singly-synchronous binary asteroids. Their evolutionary outcomes can defy the imagination, such as asteroid 1950 DA which is spinning faster than its gravitational attraction yet is held together by weak van der Waals forces (Rozitis et al. 2014), or present us with profound mysteries, such as how the Almahata Sitta meteorite could be comprised of such diverse components. Beyond these motivations, the study of rubble pile asteroid geophysics can shed insight into any solar system environment where gravitational aggregates interact in a micro-gravity setting, ranging from the protoplanetary disc to planetary ring systems. The broad study of the geophysics of aggregates in such micro-gravity environments is becoming both a unifying theme and emerging field of study. Out of the many diverse and complex forms that rubble pile asteroids take on, the study of NEA binary asteroids can in particular be used to expose the geophysics of micro-gravity aggregates. Binaries are an expression of micro-gravity geophysics due to the manner in which they form and their continuing evolution. Due to our ability to visit, probe and interact with NEA, we can also turn them into geophysical laboratories. This talk will introduce the science of the Binary Asteroid in-situ Explorer (BASiX) Discovery mission, which proposes to turn the primitive C-Type binary asteroid (175706) 1996 FG3 into such a geophysical laboratory. Exploring this body enables us to probe a broad range of rubble pile asteroid properties: internal tidal dissipation (through FG3

  20. TMI-2 criticality studies: lower-vessel rubble and analytical benchmarking

    SciTech Connect

    Westfall, R.M.; Knight, J.R.; Fox, P.B.; Herman, O.W.; Turner, J.C.

    1985-12-01

    A bounding strategy has been adopted for assuring subcriticality during all TMI-2 defueling operations. The strategy is based upon establishing a safe soluble boron level for the entire reactor core in an optimum reactivity configuration. This paper presents the determination of a fuel rubble model which yields a maximum infinite lattice multiplication factor and the subsequent application of cell-averaged constants in finite system analyses. Included in the analyses are the effects of fuel burnup determined from a simplified power history of the reactor. A discussion of the analytical methods employed and the determination of an analytical bias with benchmark crictical experiments completes the presentation. 17 tabs.

  1. VIEW LOOKING SOUTHWEST AT THE EARTH MOUND USED TO ENCASE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW LOOKING SOUTHWEST AT THE EARTH MOUND USED TO ENCASE THE INSTRUMENTATION AND CONTROL TANKS AND PROTECT EQUIPMENT. NOTE THE TEST STAND IN THE BACKGROUND RIGHT. - Marshall Space Flight Center, Redstone Rocket (Missile) Test Stand, Dodd Road, Huntsville, Madison County, AL

  2. 32. Overall view taken from top of water storage mound ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. Overall view taken from top of water storage mound showing building 154, missile assembly building in center, and building 161, fallout shelter in lower right corner, looking west - Nike Missile Battery MS-40, County Road No. 260, Farmington, Dakota County, MN

  3. Transient solutions to groundwater mounding in bounded and unbounded aquifers.

    PubMed

    Korkmaz, Serdar

    2013-01-01

    In this study, the well-known Hantush solution procedure for groundwater mounding under infinitely long infiltration strips is extended to finite and semi-infinite aquifer cases. Initially, the solution for infinite aquifers is presented and compared to those available in literature and to the numerical results of MODFLOW. For the finite aquifer case, the method of images, which is commonly used in well hydraulics, is used to be able to represent the constant-head boundaries at both sides. It is shown that a finite number of images is enough to obtain the results and sustain the steady state. The effect of parameters on the growth of the mound and on the time required to reach the steady state is investigated. The semi-infinite aquifer case is emphasized because the growth of the mound is not symmetric. As the constant-head boundary limits the growth, the unbounded side grows continuously. For this reason, the groundwater divide shifts toward the unbounded side. An iterative solution procedure is proposed. To perform the necessary computations a code was written in Visual Basic of which the algorithm is presented. The proposed methodology has a wide range of applicability and this is demonstrated using two practical examples. The first one is mounding under a stormwater dispersion trench in an infinite aquifer and the other is infiltration from a flood control channel into a semi-infinite aquifer. Results fit very well with those of MODFLOW. PMID:22974408

  4. 29. Overall view taken from top of water storage mound ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. Overall view taken from top of water storage mound showing building 104, mess hall in lower left, building 101, administration, recreation, and storage building in center, and building 103, non-commissioned officers quarters and enlisted men barracks on far right, looking northeast - Nike Missile Battery MS-40, County Road No. 260, Farmington, Dakota County, MN

  5. Test fire environmental testing operations at Mound Applied Technologies

    SciTech Connect

    1992-03-01

    This paper describes Mound Laboratory`s environmental testing operations. The function of environmental testing is to perform quality environmental (thermal, mechanical, spin, resistance, visual) testing/conditioning of inert/explosive products to assure their compliance with specified customer acceptance criteria. Capabilities, organization, equipment specifications, and test facilities are summarized.

  6. Mound ambient air surveillance program: Description and path forward

    SciTech Connect

    Bauer, L R

    1992-08-01

    The ambient air monitoring program in place at Mound has undergone a number of changes since its installation. These changes have resulted from revisions to prevailing environmental regulations and guidance. Additional voluntary upgrades and modifications are planned. This report serves to update information on sampling station locations, equipment designs, operational criteria, and planned upgrades.

  7. 28. Overall view taken from top of water storage mound ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. Overall view taken from top of water storage mound showing building 154, missile assembly building on right, Minnesota Department of Transportation communication tower in center, and Minnesota Bureau of Mines wind tunnel on left, looking southwest toward launch pad area - Nike Missile Battery MS-40, County Road No. 260, Farmington, Dakota County, MN

  8. Imported Fire Ant Mound Building in Response to Simulated Rainfall

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Imported fire ant (Solenopsis richteri x invicta) mounds in northeastern Mississippi were subjected to four treatments from late July through early September, 2006: application of water (7.5 L) and placement of an inverted 19 L bucket on top; application of water only; application of an inverted buc...

  9. Coastal defence through low crested breakwater structures: jumping out of the frying pan into the fire?

    PubMed

    Munari, Cristina; Corbau, Corinne; Simeoni, Umberto; Mistri, Michele

    2011-08-01

    The Adriatic coast of Punta Marina (Ravenna) is protected by 3-km long low crested breakwater structures (LCSs). Through a 3-years long multidisciplinar study, we assessed the impact of such defensive structures on environmental and biological condition. LCSs create pools where conditions are very different from the surrounding nearshore system. Mechanical disturbance by currents and waves varied greatly in intensity and frequency between seaward and landward sides of the structures. Sedimentary budget was positive at the landward side, but it was due to a gain on the seafloor and not on the emerged beach. The budget at seaward was negative. LCSs determine differences in benthic assemblages, alter the seasonal pattern of communities, and modify seasonal fluctuations of animal assemblages. Landward sheltered areas can be seen as "lagoonal island" surrounded by a "sea of marine habitat". Differences in ecological quality status, obtained through M-AMBI, are due to the sum of these factors. PMID:21722927

  10. Backwash process of marine macroplastics from a beach by nearshore currents around a submerged breakwater.

    PubMed

    Kataoka, Tomoya; Hinata, Hirofumi; Kato, Shigeru

    2015-12-30

    A key factor for determining the residence time of macroplastics on a beach is the process by which the plastics are backwashed offshore (backwash process). Here, we deduced the backwash process of plastic fishing floats on Wadahama Beach based on the analysis of two-year mark-recapture experiments as well as nearshore current structures revealed by sequential images taken by za webcam installed at the edge of a cliff behind the beach. The analysis results revealed the occurrence of a combination of offshore currents and convergence of alongshore currents in the surf zone in storm events around a submerged breakwater off the northern part of the beach, where 48% of the backwashed floats were last found. We conclude that the majority of the floats on the beach were transported alongshore and tended to concentrate in the convergence zone, from where they were backwashed offshore by the nearshore currents generated in the events. PMID:26561445

  11. Growth and form of the mound in Gale Crater, Mars: Slope wind enhanced erosion and transport

    NASA Astrophysics Data System (ADS)

    Kite, Edwin S.; Lewis, Kevin W.; Lamb, Michael P.; Newman, Claire E.; Richardson, Mark I.

    2013-05-01

    Ancient sediments provide archives of climate and habitability on Mars. Gale Crater, the landing site for the Mars Science Laboratory (MSL), hosts a 5-km-high sedimentary mound (Mount Sharp/Aeolis Mons). Hypotheses for mound formation include evaporitic, lacustrine, fluviodeltaic, and aeolian processes, but the origin and original extent of Gale’s mound is unknown. Here we show new measurements of sedimentary strata within the mound that indicate ˜3° outward dips oriented radially away from the mound center, inconsistent with the first three hypotheses. Moreover, although mounds are widely considered to be erosional remnants of a once crater-filling unit, we find that the Gale mound’s current form is close to its maximal extent. Instead we propose that the mound’s structure, stratigraphy, and current shape can be explained by growth in place near the center of the crater mediated by wind-topography feedbacks. Our model shows how sediment can initially accrete near the crater center far from crater-wall katabatic winds, until the increasing relief of the resulting mound generates mound-flank slope winds strong enough to erode the mound. The slope wind enhanced erosion and transport (SWEET) hypothesis indicates mound formation dominantly by aeolian deposition with limited organic carbon preservation potential, and a relatively limited role for lacustrine and fluvial activity. Morphodynamic feedbacks between wind and topography are widely applicable to a range of sedimentary and ice mounds across the Martian surface, and possibly other planets.

  12. How cold-water coral mounds modify their physical environment and therefore influence reef development

    NASA Astrophysics Data System (ADS)

    Mienis, F.; Duineveld, G.; Lavaleye, M.; van Haren, H.; Mohn, C.; Cyr, F.

    2015-12-01

    Cold-water coral framework acts as a sediment trap and as a result kilometres long and up to 360m high mound structures have formed on the SE Rockall Bank. Earlier observations showed that most of the mounds have their summits around 550 m water depth and summits have been reported as being covered with living coral. Pelagia cruises in 2012 and 2013 revealed completely new insights in mound development. Video transects across mounds with different morphology showed that summits of the highest and largest mounds are presently not covered by living coral as opposed to smaller and lower mounds which are covered with a thriving living coral framework. Measurements in the water column with CTD and near-bottom with benthic landers and thermistor string showed that turbulence is likely the most important factor influencing nutrient and food supply and thus coral growth. It seems that the large mounds have outgrown themselves and that their relatively large size and flat summits are limiting turbulence, thereby limiting oxygen, nutrient and food replenishment. Redistribution of nutrients, oxygen and food is vital for ecosystem functioning and reef development. The presence of a healthy coral cover on the summits of the small mounds was also shown by the vertical mound growth rate measured in sediment cores. These showed fourfold higher sedimentation rates during the Holocene on small mounds compared to highest mounds.

  13. Diversity of fungi from the mound nests of Formica ulkei and adjacent non-nest soils.

    PubMed

    Duff, Lyndon B; Urichuk, Theresa M; Hodgins, Lisa N; Young, Jocelyn R; Untereiner, Wendy A

    2016-07-01

    Culture-based methods were employed to recover 3929 isolates of fungi from soils collected in May and July 2014 from mound nests of Formica ulkei and adjacent non-nest sites. The abundance, diversity, and richness of species from nest mounds exceeded those of non-mound soils, particularly in July. Communities of fungi from mounds were more similar to those from mounds than non-mounds; this was also the case for non-mound soils with the exception of one non-mound site in July. Species of Aspergillus, Paecilomyces, and Penicillium were dominant in nest soils and represented up to 81.8% of the taxa recovered. Members of the genus Aspergillus accounted for the majority of Trichocomaceae from nests and were represented almost exclusively by Aspergillus navahoensis and Aspergillus pseudodeflectus. Dominant fungi from non-mound sites included Cladosporium cladosporioides, Geomyces pannorum, and species of Acremonium, Fusarium, Penicillium, and Phoma. Although mound nests were warmer than adjacent soils, the dominance of xerotolerant Aspergillus in soils from mounds and the isolation of the majority of Trichocomaceae at 25 and 35 °C suggests that both temperature and water availability may be determinants of fungal community structure in nests of F. ulkei. PMID:27192606

  14. A large submarine sand-rubble flow on kilauea volcano, hawaii

    USGS Publications Warehouse

    Fornari, D.J.; Moore, J.G.; Calk, L.

    1979-01-01

    Papa'u seamount on the south submarine slope of Kilauea volcano is a large landslide about 19 km long, 6 km wide, and up to 1 km thick with a volume of about 39 km3. Dredge hauls, remote camera photographs, and submersible observations indicate that it is composed primarily of unconsolidated angular glassy basalt sand with scattered basalt blocks up to 1 m in size; no lava flows were seen. Sulfur contents of basalt glass from several places on the sand-rubble flow and nearby areas are low (< 240 ppm), indicating that the clastic basaltic material was all erupted on land. The Papa'u sandrubble flow was emplaced during a single flow event fed from a large near-shore bank of clastic basaltic material which in turn was formed as lava flows from the summit area of Kilauea volcano disintegrated when they entered the sea. The current eruptive output of the volcano suggests that the material in the submarine sand-rubble flow represents about 6000 years of accumulation, and that the flow event occurred several thousand years ago. ?? 1979.

  15. Exploring the city of Rubble: botanical fieldwork in bombed cities in Germany after World War II.

    PubMed

    Lachmund, Jens

    2003-01-01

    In recent decades, the flora and fuana of cities have become the objects of the inter-disciplinary research field of urban ecology and related policies of urban nature conservation. Although the term "urban ecology" is quite recent, it is argued in this paper that the formation of urban nature as an object of ecological knowledge has a much longer history. For example, in Germany, after World War II, the large rubble areas that existed in all bombed cities soon became important research fields for botanists studying plant migration and vegetation development in the context of the city. This paper uses the case of these botanical research activities to shed light on the historical origins of ecological thinking about nature in the city. Drawing upon a socio-spatial approach to science and practice, the paper explores the interaction between the social and material order of the city and the formation of ecological knowledge. As will be shown, botanists studying the rubble areas created various representations (e.g., lists, statistical tabulations, maps) of urban space that contributed to the transformation of the cultural and political meaning of urban wastelands. At the same time, it will be argued, urban wastelands were practically appropriated as scientific workplaces in which these representations were locally crafted. What later became the science and politics of urban ecology is to a large extent the outcome of this mutual shaping of knowledge and urban space in the post-Second World War period. PMID:12966933

  16. Are termite mounds biofilters for methane? - Challenges and new approaches to quantify methane oxidation in termite mounds

    NASA Astrophysics Data System (ADS)

    Nauer, Philipp A.; Hutley, Lindsay B.; Bristow, Mila; Arndt, Stefan K.

    2015-04-01

    Methane emissions from termites contribute around 3% to global methane in the atmosphere, although the total source estimate for termites is the most uncertain among all sources. In tropical regions, the relative source contribution of termites can be far higher due to the high biomass and relative importance of termites in plant decomposition. Past research focused on net emission measurements and their variability, but little is known about underlying processes governing these emissions. In particular, microbial oxidation of methane (MOX) within termite mounds has rarely been investigated. In well-studied ecosystems featuring an oxic matrix above an anoxic methane-producing habitat (e.g. landfills or sediments), the fraction of oxidized methane (fox) can reach up to 90% of gross production. However, conventional mass-balance approaches to apportion production and consumption processes can be challenging to apply in the complex-structured and almost inaccessible environment of a termite mound. In effect, all field-based data on termite-mound MOX is based on one study that measured isotopic shifts in produced and emitted methane. In this study a closed-system isotope fractionation model was applied and estimated fox ranged from 10% to almost 100%. However, it is shown here that by applying an open-system isotope-pool model, the measured isotopic shifts can also be explained by physical transport of methane alone. Different field-based methods to quantify MOX in termite mounds are proposed which do not rely on assumptions of physical gas transport. A simple approach is the use of specific inhibitors for MOX, e.g. difluoromethane (CH2F2), combined with chamber-based flux measurements before and after their application. Data is presented on the suitability of different inhibitors and first results of their application in the field. Alternatively, gas-tracer methods allow the quantification of methane oxidation and reaction kinetics without knowledge of physical gas

  17. Effects of unsaturated zone on ground-water mounding

    USGS Publications Warehouse

    Sumner, D.M.; Rolston, D.E.; Marino, M.A.

    1999-01-01

    The design of infiltration basins used to dispose of treated wastewater or for aquifer recharge often requires estimation of ground-water mounding beneath the basin. However, the effect that the unsaturated zone has on water-table response to basin infiltration often has been overlooked in this estimation. A comparison was made between two methods used to estimate ground-water mounding-an analytical approach that is limited to the saturated zone and a numerical approach that incorporates both the saturated and the unsaturated zones. Results indicate that the error that is introduced by a method that ignores the effects of the unsaturated zone on ground-water mounding increases as the basin-loading period is shortened; as the depth to the water table increases, with increasing subsurface anisotropy; and with the inclusion of fine-textured strata. Additionally, such a method cannot accommodate the dynamic nature of basin infiltration, the finite transmission time of the infiltration front to the water table, or the interception of the basin floor by the capillary fringe.The design of infiltration basins used to dispose of treated wastewater or for aquifer recharge often requires estimation of ground-water mounding beneath the basin. However, the effect that the unsaturated zone has on water-table response to basin infiltration often has been overlooked in this estimation. A comparison was made between two methods used to estimate ground-water mounding - an analytical approach that is limited to the saturated zone and a numerical approach that incorporates both the saturated and the unsaturated zones. Results indicate that the error that is introduced by a method that ignores the effects of the unsaturated zone on ground-water mounding increases as the basin-loading period is shortened; as the depth to the water table increases, with increasing subsurface anisotropy; and with the inclusion of fine-textured strata. Additionally, such a method cannot accommodate the

  18. Spatial variability in community composition on a granite breakwater versus natural rocky shores: lack of microhabitats suppresses intertidal biodiversity.

    PubMed

    Aguilera, Moisés A; Broitman, Bernardo R; Thiel, Martin

    2014-10-15

    Strong differences have been observed between the assemblages on artificial reefs and on natural hard-bottom habitats worldwide, but little is known about the mechanisms that cause contrasting biodiversity patterns. We examined the influence of spatial attributes in relation to both biogenic and topographic microhabitats, in the distribution and composition of intertidal species on both artificial and natural reefs. We found higher small-scale spatial heterogeneity on the natural reef compared with the study breakwater. Species richness and diversity were associated with a higher availability of crevices, rock pools and mussels in natural habitats. Spatial distribution of certain grazers corresponded well with the spatial structure of microhabitats. In contrast, the lack of microhabitats on the breakwater resulted in the absence of several grazers reflected in lower species richness. Biogenic and topographic microhabitats can have interactive effects providing niche opportunities for multiple species, explaining differences in species diversity between artificial versus natural reefs. PMID:25103901

  19. A non-intrusive and continuous-in-space technique to investigate the wave transformation and breaking over a breakwater

    NASA Astrophysics Data System (ADS)

    Ferrari, Simone; Grazia Badas, Maria; Querzoli, Giorgio

    2016-03-01

    To design longshore breakwaters, the evaluation of the wave motion transformations over the structures and of the energy they are able to absorb, dissipate and reflect is necessary. To characterize features and transformations of monochromatic wave trains above a breakwater, both submerged and emerged, we have designed and developed a non-intrusive and continuous-in-space technique, based on Image Analysis, and carried out an experimental campaign, in a laboratory flume equipped with a wave-maker, in order to test it. The investigation area was lighted with a light sheet and images were recorded by a video-camera. The working fluid was seeded with non buoyant particles to make it bright and clearly distinct from dark background and breakwater. The technique, that is based on a robust algorithm to identify the free surface, has showed to properly work also in prohibitive situations for traditional resistive probes (e.g., very shallow waters and/or breaking waves) and to be able to measure the free surface all over the investigation field in a non-intrusive way. Two kind of analysis were mainly performed, a statistical and a spectral one. The peculiarities of the measurement technique allowed to describe the whole wave transformation and to supply useful information for design purposes.

  20. Reef mounds indicate timing of hydrocarbon charge off Seychelles

    SciTech Connect

    Plummer, P.

    1998-07-06

    Carbonate mounds developed on Coetivy Bank and the northern Seychelles Plateau appear to have formed in response to pulses of hydrocarbon fluid migration along underlying faults during the late Paleocene and late Eocene. Gas chimneys emanating from these mounds are evident on seismic data, while gas sniffer and/or UV fluorescence anomalies have been recorded in the overlying waters. Such a combination of hydrocarbon anomalies is indicative of minor active gas seepage and confirms the prospectivity of these features and their underlying sequences. Recently it has also been realized that both authigenic and biogenic carbonates proliferate above faults from which hydrocarbon seepage occurs, forming chemosynthetic reefs. When identified on seismic data, such reef/fault associations constitute seismic hydrocarbon indicators (SHIs), and the reefs/faults off Seychelles have been interpreted as SHIs. This paper discusses the geology, source rocks, thermal history, and chemosynthetic reefs.

  1. Spectral response of the coral rubble, living corals, and dead corals: study case on the Spermonde Archipelago, Indonesia

    NASA Astrophysics Data System (ADS)

    Nurdin, Nurjannah; Komatsu, Teruhisa; Yamano, Hiroya; Arafat, Gulam; Rani, Chair; Akbar AS, M.

    2012-10-01

    Coral reefs play important ecological services such as providing foods, biodiversity, nutrient recycling etc. for human society. On the other hand, they are threatened by human impacts such as illegal fishing and environmental changes such as rises of sea water temperature and sea level due to global warming. Thus, it is very important to monitor dynamic spatial distributions of coral reefs and related habitats such as coral rubble, dead coral, bleached corals, seagrass, etc. Hyperspectral data, in particular, offer high potential for characterizing and mapping coral reefs because of their capability to identify individual reef components based on their detailed spectral response. We studied the optical properties by measuring in situ spectra of living corals, dead coral and coral rubble covered with algae. Study site was selected in Spermonde archipelago, South Sulawesi, Indonesia because this area is included in the highest diversity of corals in the world named as Coral Triangle, which is recognized as the global centre of marine biodiversity and a global priority for conservation. Correlation analysis and cluster analysis support that there are distinct differences in reflectance spectra among categories. Common spectral characteristic of living corals, dead corals and coral rubble covered with algae was a reflectance minimum at 674 nm. Healthy corals, dead coral covered with algae and coral rubble covered with algae showed high similarity of spectral reflectance. It is estimated that this is due to photsynthetic pigments.

  2. Cohesive forces prevent the rotational breakup of rubble-pile asteroid (29075) 1950 DA.

    PubMed

    Rozitis, Ben; MacLennan, Eric; Emery, Joshua P

    2014-08-14

    Space missions and ground-based observations have shown that some asteroids are loose collections of rubble rather than solid bodies. The physical behaviour of such 'rubble-pile' asteroids has been traditionally described using only gravitational and frictional forces within a granular material. Cohesive forces in the form of small van der Waals forces between constituent grains have recently been predicted to be important for small rubble piles (ten kilometres across or less), and could potentially explain fast rotation rates in the small-asteroid population. The strongest evidence so far has come from an analysis of the rotational breakup of the main-belt comet P/2013 R3 (ref. 7), although that was indirect and poorly constrained by observations. Here we report that the kilometre-sized asteroid (29075) 1950 DA (ref. 8) is a rubble pile that is rotating faster than is allowed by gravity and friction. We find that cohesive forces are required to prevent surface mass shedding and structural failure, and that the strengths of the forces are comparable to, though somewhat less than, the forces found between the grains of lunar regolith. PMID:25119234

  3. A Reevaluation of the DeKalb Mounds of Northern Illinois

    NASA Astrophysics Data System (ADS)

    Konen, M.; Curry, B.

    2007-12-01

    We re-examined the classic DeKalb Mounds of Northern Illinois in order to better understand their genesis, morphology, spatial distribution, and usefulness in reconstructing deglacial and postglacial environments. Flemal et al. (1973) interpreted the mounds to be relict pingos resulting from an intense periglacial environment during the late Wisconsin. Thousands of mounds occur in the study area. The mounds range in size from 20 m to more than 5 km in diameter and typically rise 1 to 8 m above the surrounding loess mantled till surface. These low relief mounds are composed of either a raised border surrounding a low center ("donuts") or are flat-topped ("pancakes"). Modern soil properties are strongly related to mound position and subtle sedimentologic and topographic changes. In some locations multiple mounds appear to be superimposed on one another. The typical mound stratigraphy includes subglacial diamicton at the base, less than 1 m of glaciofluvial sands and gravels or debris flow diamicton, 1 to 6 m of fossiliferous, rhythmically bedded lake sediment, 0.3 to 3 m of glaciofluvial sands and gravels or debris flow diamicton, all capped by approximately 1.2 m of loess. The lake sediment is rich in ostracodes and tundra plant remains. Smaller mounds are typically symmetrical while the larger mounds are more elliptical in shape with a long axis trending northeast to southwest. Many of the larger mounds appear to be aggregates of smaller lakes that coalesced as glacial ice stagnated. Our reinterpretation of the mounds is that there genesis is related to deglaciation and ice-stagnation and not to post glacial permafrost processes. We interpret all of the DeKalb Mounds to be ice-walled lakes and not pingos.

  4. Are reefs and mud mounds really so different?

    NASA Astrophysics Data System (ADS)

    Wood, Rachel

    2001-12-01

    Although both 'ecologic reefs' and mud mounds are demonstrably rigid, framework reefs, they are still considered to be distinct in terms of their dominant processes of formation and preferred environmental settings. This distinction has rested largely upon the assumption that ecologic reefs are dominated by skeletal metazoans growing in shallow waters, in contrast to the complex autochthonous micrite-supported cavity systems that characterise deep-water mud mounds, now considered to represent either organomineralic deposits (where carbonate precipitation has taken place in association with nonliving organic substrates to form 'automicrite') or various types of microbialite (where carbonate forms as a direct result of the physiological activity or decay of benthic microorganisms). Yet, such autochthonous micrite is increasingly recognised as an important component of many ancient shallow ecologic reefs as well as some modern coral reefs, and indeed may contribute locally up to 80% of the reef rock. These observations raise doubts as to the validity of current fabric-based definitions used to distinguish between mud mounds and ecologic reefs. Whether the autochthonous micrite in mud mounds proves to be dominated by either automicrite or microbialite, both require particular environmental conditions for their formation. Automicrites form where surplus organic matter from metazoans has degraded to release quantities of acidic amino acids with a significant ability to bind Ca 2+ , and microbialite formation also often requires either unusual marine chemistries or ecological conditions. Such conditions might include changes in terrigenous influx, ground water seepage, local anoxia, and increases in the pH of interstitial reef waters or in nutrient concentration.

  5. Seismic characterization of mound reservoirs using iterative modeling procedure

    SciTech Connect

    Rafison, B.J.; Stuart, C.J.

    1989-04-01

    A seismic stratigraphic analysis based on seismic attribute and stratigraphic modeling techniques was done on Paleocene submarine fan mounds in two North Sea blocks. The principal objective of these studies was to develop new interpretation concepts for resolving and mapping sandstone buildups and channel fills. Improved resolution and interpretation of these features should contribute to development of Paleocene exploration plays and reservoir characterization in these blocks.

  6. Non-dune eolian sand in Indian mounds

    NASA Astrophysics Data System (ADS)

    Tanner, William F.

    1980-02-01

    Indian mounds, near Careyville, Florida, about 2.0 m high, are located on hillsides and hilltops 10 to 20 m above the floodplain of the nearest river (Choctawhatchee). Each mound is composed largely of quartz sand, with a scattering of artefacts and stream pebbles (not in layers), but with no visible bedding. Probability plots showed 25 Gaussian distributions, 18 having the 'dune hump', three having the 'surf break' and nine being doubly-truncated or having other patterns of unknown or uncertain origin. The surf breaks probably were inherited from pre-Pleistocene marine terraces in the area. The pebbles and the sand were not introduced by the same agency. The sand probability plots, taken as a set, indicate an eolian origin. The rough symmetry of the mounds, and the lack of cross-bedding, argue against a migrating dune origin. On a variability plot (showing the variability of the means versus the variability of the standard deviations), one suite of samples fell clearly within the 'dune' number field, a second suite in the overlap area between 'dune' and 'beach', and a third suite, taken immediately adjacent to a creek bed, plotted in the overlap area between 'beach' and 'coastal plain stream'. The pebbles, of common Southern Appalachian types, are attributed to the activities of the inhabitants, perhaps children. The sand is thought to have been carried by the wind, perhaps from nearby river sand bars, or from areas burned either by lightning-set wildfires or as part of "slash-and-burn" agriculture. The mounds are thought to represent clearings (for huts), and hence good trapping devices for wind-borne sand.

  7. EG&G Mound Applied Technologies payroll system

    SciTech Connect

    Not Available

    1992-02-07

    EG&G Mound Applied Technologies, Inc., manages and operates the Mound Facility, Miamisburg, Ohio, under a cost-plus-award-fee contract administered by the Department of Energy`s Albuquerque Field Office. The contractor`s Payroll Department is responsible for prompt payment in the proper amount to all persons entitled to be paid, in compliance with applicable laws, regulations, and legal decisions. The objective was to determine whether controls were in place to avoid erroneous payroll payments. EG&G Mound Applied Technologies, Inc., did not have all the internal controls required by General Accounting Office Title 6, ``Pay, Leave, and Allowances.`` Specifically, they did not have computerized edits, separation of duties and responsibilities, and restricted access to payroll data files. This condition occurred because its managers were not aware of Title 6 requirements. As a result, the contractor could not assure the Department of Energy that payroll costs were processes accurately; and fraud, waste, or abuse of Department of Energy funds could go undetected. Our sample of 212 payroll transactions from a population of 66,000 in FY 1991 disclosed only two minor processing errors and no instances of fraud, waste or abuse.

  8. Incineration of LWR-type waste at Mound Facility

    SciTech Connect

    Alexander, B.M.; Grimm, R.S.; Doty, J.W. Jr.

    1980-01-01

    The Mound Cyclone Incinerator, demonstrated over several years for the combustion of radwaste containing plutonium, is now being developed for volume reduction of radwaste containing mixed beta- and gamma-emitters, from LWR facilities. To this end, a laboratory-scale feasibility study was developed and executed. Development of the feasibility study was based on known characteristics of LWR waste and on operating data compiled for the Mound Cyclone Incinerator since 1975. Feed spiked with several isotopes found in LWR waste was burned in the laboratory-scale cyclone incinerator, and samples were collected and analyzed. From these data, the applicability of cyclone incineration was demonstrated, and an efficient scrub liquor composition was chosen for the offgas treatment system. A Health Physics survey of the incinerator system after incineration of 220 ..mu..Ci of beta/gamma activity showed no exposure readings above background level. Future work planned includes incineration of simulated LWR waste in the full-scale Mound Cyclone Incinerator to begin later this year.

  9. Cold Water Coral Mounds and Early Holocene Climate Change

    NASA Astrophysics Data System (ADS)

    Readman, P. W.; O'Reilly, B. M.; Shannon, P. M.

    2003-12-01

    Cold-water coral mounds occur in discrete clustered populations over a broad region from the glaciated Norwegian continental margins to the non-glaciated margins of Iberia and northwest Africa. They are potentially sensitive indicators of change in oceanic circulation, coupled to past climate change. Here we report on an interesting correlation between the Holocene growth of a mound population west of Ireland and early Holocene palaeoclimatic variations in the North Atlantic region, notably the well documented 8.2 kyr cold event. An accurate age structure for the mound population is calculated using recent growth rate estimates for the main coral framework constructor L. pertusa and a previously formulated population growth model. The calculated curve for the Holocene period fits the observed population data well, except for a pronounced and significant deflection in the data trend beginning at about 8500 calendar years (cal. yr) ago in the early Holocene. This date corresponds to the time (~8470 cal. yr) that the glacial lakes Agassiz and Ojibway, which were once dammed by a remnant of the Laurentide ice sheet, drained catastrophically into the Labrador sea releasing >1014 m3 of fresh water. The 8.2 kyr event had as much a global effect on the large-scale structure of deep-water aphotic ecosystems as it did on continental shelf and terrestrial ecosystems.

  10. Using Cold-water Coral Mini-mounds as Analogue for Giant Mound Growth: Assessment of Environmental Drivers and Anthropogenic Impact

    NASA Astrophysics Data System (ADS)

    Collart, T.; Stewart, H. A.; Howell, K.; Bourillet, J. F.; Llave, E.; Blamart, D.; Mienis, F.; Van Rooij, D.

    2015-12-01

    Cold-water coral (CWC) reefs are formed by framework building scleratinians Lophelia pertusa and Madrepora oculata that baffle sediment and over time, have the potential to develop into large coral mounds of up to 300m high (e.g. Belgica Mound Province). The detailed mechanisms of initiation and build-up of such large CWC mounds are however not yet fully understood. It is therefore essential to study smaller mounds (often termed "mini-mounds") that can be interpreted as earlier growth stages that haven't had the time to coalesce and develop into larger mounds. The FWO Minimound project (2013-2017) aims to investigate CWC mini-mounds within the Bay of Biscay (European Margin) in order to determine the impact of: (1) palaeoceanographic changes related to glacial-interglacial climate change in the last 15 ka, (2) hydrocarbon seepage processes and (3) anthropogenic fishing activities on CWC habitats. The project targets three minimound provinces: the Ferrol Canyon (Cantabrian Margin), the Guilvinec Canyon (Armorican Margin) and the Explorer and Dangeard Canyons (Celtic Margin). These mini-mounds are fossil and occur at relative shallow depths on the interface between the Eastern North Atlantic Central Water (ENACW) and the Mediterranean Outflow Water (MOW). Contrastingly, most living CWC reefs in this region of the Atlantic, dwell in the deeper MOW depth range, relying on the density and dynamics of this water mass for their food supply. In order to investigate the initiation, growth and demise of CWC mini-mounds, 35m of USBL guided sediment cores were retrieved from the Explorer and Dangeard Interfluves. We present data of sedimentological, geochemical and palaeoceanographic analyses throughout the cores, coupled with high-resolution geophysical data. Preliminary results indicate that the mound base is associated with a strong shift in sedimentation regime potentially linked to climate driven palaeoceanographic changes of the MOW-ENACW interface.

  11. Characterization of the Burma Road Rubble Pit at the Savannah River Site, Aiken, South Carolina

    SciTech Connect

    Ward, K.G.; Frazier, W.L.; McAdams, T.D.; McFalls, S.L.; Rabin, M.; Voss, L. |

    1996-05-01

    The Burma Road Rubble Pit (BRRP) is located at the Savannah River Site (SRS). The BRRP unit consists of two unlined earthen pits dug into surficial soil and filled with various waste materials. It was used from 1973--1983 for the disposal of dry inert rubble such as metal, concrete, lumber, poles, light fixtures, and glass. No record of the disposal of hazardous substances at the BRRP has been found. In 1983, the BRRP was closed by covering it with soil. In September 1988, a Ground Penetrating Radar survey detected three disturbed areas of soil near the BRRP, and a detailed and combined RCRA Facility Investigation/Remedial Investigation was conducted from November 1993 to February 1994 to determine whether hazardous substances were present in the subsurface, to evaluate the nature and extent of contamination, and to evaluate the risks posed to the SRS facility due to activities conducted at the BRRP site. Metals, semi-volatile organic compounds, volatile organic compounds, radionuclides and one pesticide (Aldrin) were detected in soil and groundwater samples collected from seventeen BRRP locations. A baseline risk assessment (BRA) was performed quantitatively to evaluate whether chemical and radionuclide concentrations detected in soil and groundwater at the BRRP posed an unacceptable threat to human health and the environment. The exposure scenarios identifiable for the BRRP were for environmental researchers, future residential and occupational land use. The total site noncancer hazard indices were below unity, and cancer risk levels were below 1.0E-06 for the existing and future case environmental researcher scenario. The future case residential and occupational scenarios showed total hazard and risk levels which exceeded US EPA criterion values relative to groundwater scenarios. For the most part, the total carcinogenic risks were within the 1.0E-04 to 1.0E-06 risk range. Only the future adult residential scenario was associated with risks exceeding 1.0E-04.

  12. Small-Scale Gopher and Plant Activity Organizes a Simulated Landscape Into Mound-Pool Topography

    NASA Astrophysics Data System (ADS)

    Lewis, C. P.

    2011-12-01

    The Mima-mound-and-vernal-pool topography of California is rich in endemic species, but we do not know how this unusual environment is created or maintained. Fossorial rodents have been observed to move soil upwards at annual rates sufficient to maintain the mounds despite erosion, but there is no tested explanation of this behavior. We propose that the mounds are an emergent effect of small-scale (10 cm, 1 day) interactions between topography, hydrology, plant growth, and rodent burrowing. A cellular automata simulation of these both generates and maintains mound-pool topography with minimal dependence on initial conditions, and can also describe mound morphogenesis on slopes, where observed mound geometry is distinct from that on level ground.

  13. Variability of soil properties within large termite mounds in South Katanga, DRC - origins and applications.

    NASA Astrophysics Data System (ADS)

    Erens, Hans; Bazirake Mujinya, Basile; Boeckx, Pascal; Baert, Geert; Mees, Florias; Van Ranst, Eric

    2014-05-01

    The miombo woodlands of South Katanga (D.R. Congo) are characterized by a high spatial density of large conic termite mounds built by Macrotermes falciger (3 to 5 ha-1). With an average height of 5.05 m and diameter of 14.88 m, these are some of the largest biogenic structures in the world. The mound material is known to differ considerably from the surrounding Ferralsols. Specifically, mound material exhibits a finer texture, higher CEC and exchangeable basic cation content, lower organic matter content, and an accumulation of phosphorous, nitrate and secondary carbonates. However, as demonstrated by the present study, these soil properties are far from uniform within the volume of the mound. The termites' nesting and foraging activity, combined with pedogenic processes over extended periods of time, generates a wide range of physical, chemical, and biological conditions in different parts of the mound. Analysis of samples taken along a cross-section of a large active mound allowed generating contour plots, thus visualizing the variability of soil properties within the mound. The central columns of three other mounds were sampled to confirm apparent trends. The contour plots show that the mounds comprise four functional zones: (i) the active nest, found at the top; (ii) an accumulation zone , in more central parts of the mound; (iii) a dense inactive zone, surrounding the accumulation zone and consisting of accumulated erosion products from former active nests; and (iv) the outer mantle, characterized by intense varied biological activity and by a well-developed soil structure. Intermittent leaching plays a key role in explaining these patterns. Using radiocarbon dating, we found that some of these mounds are at least 2000 years old. Their current size and shape is likely the result of successive stages of erosion and rebuilding, in the course of alternating periods of mound abandonment and recolonization. Over time, termite foraging combined with limited leaching

  14. Prediction of seaward slope recession in berm breakwaters using M5' machine learning approach

    NASA Astrophysics Data System (ADS)

    Hosseini, Alireza Sadat; Shafieefar, Mehdi

    2016-03-01

    In the design process of berm breakwaters, their front slope recession has an inevitable rule in large number of model tests, and this parameter being studied. This research draws its data from Moghim's and Shekari's experiment results. These experiments consist of two different 2D model tests in two wave flumes, in which the berm recession to different sea state and structural parameters have been studied. Irregular waves with a JONSWAP spectrum were used in both test series. A total of 412 test results were used to cover the impact of sea state conditions such as wave height, wave period, storm duration and water depth at the toe of the structure, and structural parameters such as berm elevation from still water level, berm width and stone diameter on berm recession parameters. In this paper, a new set of equations for berm recession is derived using the M5' model tree as a machine learning approach. A comparison is made between the estimations by the new formula and the formulae recently given by other researchers to show the preference of new M5' approach.

  15. Thermal Analysis of the Mound One Kilowatt Package

    SciTech Connect

    Or, Chuen T.

    1993-01-01

    The Mound One Kilowatt (1 KW) package was designed for the shipment of plutonium (Pu-238) with not more than 1 kW total heat dissipation. To comply with regulations, the Mound 1 kW package has to pass all the requirements under Normal Conditions of Transport (NCT; 38 degrees C ambient temperature) and Hypothetical Accident Conditions (HAC; package engulfed in fire for 30 minutes). Analytical and test results were presented in the Safety Analysis Report for Packaging (SARP) for the Mound 1 kW package, revision 1, April 1991. Some issues remained unresolved in that revision. In March 1992, Fairchild Space and Defense Corporation was commissioned by the Department of Energy to perform the thermal analyses. 3-D thermal models were created to perform the NCT and HAC analyses. Four shipping configurations in the SARP revision 3 were analyzed. They were: (1) The GPHS graphite impact shell (GIS) in the threaded product can (1000 W total heat generation); (2) The fueled clads in the welded product can (1000 W total heat generation); (3) The General Purpose Heat Source (GPHS) module (750 W total heat generation); and (4) The Multi-Hundred Watt (MHW) spheres (810 W total heat generation). Results from the four cases show that the GIS or fuel clad in the product can is the worse case. The temperatures predicted under NCT and HAC in all four cases are within the design limits. The use of helium instead of argon as cover gas provides a bigger safety margin. There is a duplicate copy.

  16. Morphology and spatial patterns of Macrotermes mounds in the SE Katanga, D.R. Congo

    NASA Astrophysics Data System (ADS)

    Bazirake Mujinya, Basile; Mees, Florias; Erens, Hans; Baert, Geert; Van Ranst, Eric

    2015-04-01

    The spatial distribution patterns and morphological characteristics of Macrotermes falciger mounds were investigated in the Lubumbashi area, D.R. Congo. Examination of the spatial patterns of M. falciger mounds on high resolution satellite images reveals a mean areal number density of 2.9 ± 0.4 mounds ha-1. The high relative number of inactive mounds in the region, along with their regular distribution pattern, suggests that current termite mound occurrences are largely palaeostructures. Mound positions in the habitat are consistent with intraspecific competition rather than soil and substrate characteristics as controlling factor. Detailed morphological description of five deep termite-mound profiles (~7 m height/depth) shows that carbonate pedofeatures are present in all studied profiles, in contrast to the control soils. They mainly occur in the form of soft powdery masses, nodules and coatings on ped faces, all clearly pedogenic. Carbonate coatings occur mainly between 1 m above the soil surface and 1 m below that level in all mound profiles. Carbonate nodules do show a different distribution pattern at each site. Furthermore, when the studied profiles are considered to represent a toposequence, the stone layer occurs at greater depth in topographically low areas compared to crest and slope positions, which is mainly conditioned by erosion. The clay content of epigeal mounds increases from the summit to the toe slope, which can be largely related to differences in parent material. The Mn-Fe oxide concentrations occurring in all studied termite mound profiles reflect a seasonally high perched water table beneath the mound, which is more pronounced at the lower slope positions.

  17. Plant Mounds as Concentration and Stabilization Agents for Actinide Soil Contaminants in Nevada

    SciTech Connect

    D.S. Shafer; J. Gommes

    2009-02-03

    Plant mounds or blow-sand mounds are accumulations of soil particles and plant debris around the base of shrubs and are common features in deserts in the southwestern United States. An important factor in their formation is that shrubs create surface roughness that causes wind-suspended particles to be deposited and resist further suspension. Shrub mounds occur in some plant communities on the Nevada Test Site, the Nevada Test and Training Range (NTTR), and Tonopah Test Range (TTR), including areas of surface soil contamination from past nuclear testing. In the 1970s as part of early studies to understand properties of actinides in the environment, the Nevada Applied Ecology Group (NAEG) examined the accumulation of isotopes of Pu, 241Am, and U in plant mounds at safety experiment and storage-transportation test sites of nuclear devices. Although aerial concentrations of these contaminants were highest in the intershrub or desert pavement areas, the concentration in mounds were higher than in equal volumes of intershrub or desert pavement soil. The NAEG studies found the ratio of contaminant concentration of actinides in soil to be greater (1.6 to 2.0) in shrub mounds than in the surrounding areas of desert pavement. At Project 57 on the NTTR, 17 percent of the area was covered in mounds while at Clean Slate III on the TTR, 32 percent of the area was covered in mounds. If equivalent volumes of contaminated soil were compared between mounds and desert pavement areas at these sites, then the former might contain as much as 34 and 62 percent of the contaminant inventory, respectively. Not accounting for radionuclides associated with shrub mounds would cause the inventory of contaminants and potential exposure to be underestimated. In addition, preservation of shrub mounds could be important part of long-term stewardship if these sites are closed by fencing and posting with administrative controls.

  18. Characteristics and origin of Earth-mounds on the Eastern Snake River Plain, Idaho

    SciTech Connect

    Tullis, J.A.

    1995-09-01

    Earth-mounds are common features on the Eastern Snake River Plain, Idaho. The mounds are typically round or oval in plan view, <0.5 m in height, and from 8 to 14 m in diameter. They are found on flat and sloped surfaces, and appear less frequently in lowland areas. The mounds have formed on deposits of multiple sedimentary environments. Those studied included alluvial gravel terraces along the Big Lost River (late Pleistocene/early Holocene age), alluvial fan segments on the flanks of the Lost River Range (Bull Lake and Pinedale age equivalents), and loess/slopewash sediments overlying basalt flows. Backhoe trenches were dug to allow characterization of stratigraphy and soil development. Each mound has features unique to the depositional and pedogenic history of the site; however, there are common elements to all mounds that are linked to the history of mound formation. Each mound has a {open_quotes}floor{close_quotes} of a sediment or basement rock of significantly different hydraulic conductivity than the overlying sediment. These paleosurfaces are overlain by finer-grained sediments, typically loess or flood-overbank deposits. Mounds formed in environments where a sufficient thickness of fine-grained sediment held pore water in a system open to the migration to a freezing front. Heaving of the sediment occurred by the growth of ice lenses. Mound formation occurred at the end of the Late Pleistocene or early in the Holocene, and was followed by pedogenesis. Soils in the mounds were subsequently altered by bioturbation, buried by eolian deposition, and eroded by slopewash runoff. These secondary processes played a significant role in maintaining or increasing the mound/intermound relief.

  19. RCRA Facility Investigation/Remedial Investigation Report for Gunsite 720 Rubble Pit Unit (631-16G) - March 1996

    SciTech Connect

    Palmer, E.

    1996-03-01

    Gunsite 720 Rubble Pit Unit is located on the west side of SRS. In the early to mid 1980`s, while work was being performed in this area, nine empty, partially buried drums, labeled `du Pont Freon 11`, were found. As a result, Gunsite 720 became one of the original waste units specified in the SRS RCRA Facility Assessment (RFA). The drums were excavated on July 30, 1987 and placed on a pallet at the unit. Both the drums and pallet were removed and disposed of in October 1989. The area around the drums was screened during the excavation and the liquid (rainwater) that collected in the excavated drums was sampled prior to disposal. No evidence of hazardous materials was found. Based on the review of the analytical data and screening techniques used to evaluate all the chemicals of potential concern at Gunsite 720 Rubble Pit Unit, it is recommended that no further remedial action be performed at this unit.

  20. Estimating the angle of friction of blocks on rubble-pile asteroid Itokawa

    NASA Astrophysics Data System (ADS)

    Aoki, T.; Nakamura, A.; Hirata, N.

    2014-07-01

    The angle of internal friction and cohesion are measures of the mobility or strength of granular material and are key parameters that control granular processes such as landslides. The shape and spin of a rubble pile or self-gravitating body are dependent on these parameters [1]. These are also thought to be responsible for the crater-formation process [2]. Therefore, it is important to be able to estimate these parameters to better understand how granular processes work on rubble- pile bodies and regolith surfaces. This paper presents an estimate of the angle of internal friction of blocks on the surface of the near-Earth asteroid Itokawa [3]. Our analysis is based on a study of terrestrial granular particles that showed a linear relationship between the angle of friction and the circularity of the two-dimensional projected image of the particles [4]. The circularity is defined as 4πA / L^2, where A and L denote the projected area and the circumference, respectively. The circularity of the contour of the Itokawa block was measured using Image-J [5]. Similar image analyses were conducted for a range of granular materials in the laboratory. The figure shows that the circularity of the Itokawa blocks is similar to that of collisional fragments [6] and silica sand particles. We measured the angle of internal friction for some of the granular materials used in the shape analyses in a direct shear test and obtained a linear relationship between the circularity and angle of internal friction. Using this empirical relationship and the measured circularity of the Itokawa blocks, we estimated that the angle of internal friction of the Itokawa blocks is about 40 degrees. This is consistent with the slope distribution of the Itokawa surface: most of the surface of Itokawa is inclined within 40 degrees [3]. We use the resulting angle of internal friction to discuss the stability of a large boulder, called Pencil. Pencil has a distinct positive relief, as if part of the

  1. Dupuit-Forchheimer theories for the shape of groundwater recharge mounds

    NASA Astrophysics Data System (ADS)

    Brock, Richard R.

    1991-05-01

    The nonlinear Dupuit-Forchheimer theory and two linearized versions are considered as to their applicability for giving accurate results on recharge mound shapes beneath strip and square basins. Results on mound rises from the approximate theories are compared with those from the nonlinear theory to determine criteria for the use of the approximate theories.

  2. IMPORTED FIRE ANT (HYMENOPTERA: FORMICIDAE) MOUND SHAPE CHARACTERISTICS ALONG A NORTH-SOUTH GRADIENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Imported fire ant mound shape characteristics (south facing slope angle and area, mound height, and basal elongation in the plane of the ground) were quantified in 2005 and 2006 at a number of locations from about 30° 25’ N (Long Beach, Mississippi, USA) to 35° 3’ N (Fayetteville, Tennessee, USA). ...

  3. Plants in Your Ants: Using Ant Mounds to Test Basic Ecological Principles

    ERIC Educational Resources Information Center

    Zettler, Jennifer A.; Collier, Alexander; Leidersdorf, Bil; Sanou, Missa Patrick

    2010-01-01

    Urban students often have limited access to field sites for ecological studies. Ubiquitous ants and their mounds can be used to study and test ecology-based questions. We describe how soil collected from ant mounds can be used to investigate how biotic factors (ants) can affect abiotic factors in the soil that can, in turn, influence plant growth.

  4. An Exercise in Field Archaeology for the Gifted: Fake Mound, Genuine Scholarship.

    ERIC Educational Resources Information Center

    White, John R.

    1992-01-01

    At an archaeology camp program for gifted youngsters, students ages 11-16 built a mound with 5 archaeological levels, for future exploration. The "fake" mound ensured that student interest would be maintained, that students would learn about special problems and situations, and that irreplaceable bits of prehistory would not risk being damaged.…

  5. Controls on Pennsylvanian algal-mound distribution in mid-continent North America

    SciTech Connect

    Price, R.C.; Mitchell, J.C.; Ravn, R.L.

    1985-02-01

    Middle (Desmoinesian) and Upper (Missourian) Pennsylvanian phylloid algal-mound distribution in Missouri, Kansas, and Oklahoma is largely controlled by subtle sea-floor topography. Topographic highs served as loci favoring initiation and continued growth of complexes. Topographic highs controlling mound distribution are the shelf-edge rise in northeastern Oklahoma, the Bourbon arch in southeastern Kansas and the Mine Creek prodeltaic shale buildup in west-central Missouri. Outcrop studies document controls on development of these mounds and reveal the potential for development of stacked mounds. This will help exploration for these features in the subsurface to the west. The shelf-edge rise and Mine Creek prodeltaic shale buildup control the location of the Oologah algal-mound complex and an isolated algal mound in the Pawnee Limestone, respectively. These apparently were positive features only during Middle Pennsylvanian time. In contrast, the Bourbon arch apparently was controlled by basement faulting and remained high for a more-extended period of time. Both Middle and Upper Pennsylvanian algal mounds coincide with the geographic position of the Bourbon arch and result in a stacked-mound complex. Evidence suggesting that the Bourbon arch was a positive feature are (1) thinning of clastics over the feature and (2) change from anoxic, black, fissile, and phosphatic basinal shales to oxygenated, diversely fossiliferous gray shales over the arch.

  6. A 2 km-size asteroid challenging the rubble-pile spin barrier - A case for cohesion

    NASA Astrophysics Data System (ADS)

    Polishook, D.; Moskovitz, N.; Binzel, R. P.; Burt, B.; DeMeo, F. E.; Hinkle, M. L.; Lockhart, M.; Mommert, M.; Person, M.; Thirouin, A.; Thomas, C. A.; Trilling, D.; Willman, M.; Aharonson, O.

    2016-03-01

    The rubble pile spin barrier is an upper limit on the rotation rate of asteroids larger than ∼200-300 m. Among thousands of asteroids with diameters larger than ∼300 m, only a handful of asteroids are known to rotate faster than 2.0 h, all are in the sub-km range (⩽0.6 km). Here we present photometric measurements suggesting that (60716) 2000 GD65, an S-complex, inner-main belt asteroid with a relatively large diameter of 2.3-0.7+0.6km , completes one rotation in 1.9529 ± 0.0002h . Its unique diameter and rotation period allow us to examine scenarios about asteroid internal structure and evolution: a rubble pile bound only by gravity; a rubble-pile with strong cohesion; a monolithic structure; an asteroid experiencing mass shedding; an asteroid experiencing YORP spin-up/down; and an asteroid with a unique octahedron shape results with a four-peak lightcurve and a 3.9 h period. We find that the most likely scenario includes a lunar-like cohesion that can prevent (60716) 2000 GD65 from disrupting without requiring a monolithic structure or a unique shape. Due to the uniqueness of (60716) 2000 GD65, we suggest that most asteroids typically have smaller cohesion than that of lunar regolith.

  7. The Rubble Rescue Radar (RRR): A low power hand-held microwave device for the detection of trapped human personnel

    SciTech Connect

    Haddad, W.S.

    1997-04-10

    Each year, innocent human lives are lost in collapsed structures as a result of both natural and man-made disasters. We have developed a prototype device, called the Rubble Rescue Radar (RRR) as a aid to workers trying to locate trapped victims in urban search and rescue operations. The RRR is a motion sensor incorporating Micropower Impulse Radar and is capable of detecting human breathing motions through reinforced concrete. It is lightweight, and designed to be handled by a single operator for local searches in areas where trapped victims are expected. Tests of the first prototype device were conducted on site at LLNL using a mock rubble pile consisting of a reinforced concrete pipe with two concrete floor slabs placed against one side, and random concrete and asphalt debris piled against the other. This arrangement provides safe and easy access for instruments and/or human subjects. Breathing signals of a human subject were recorded with the RRR through one floor slab plus the wall of the pipe, two slabs plus the wall of the pipe, and the random rubble plus the wall of the pipe. Breathing and heart beat signals were also recorded of a seated human subject at a distance of 1 meter with no obstructions. Results and photographs of the experimental work are presented, and a design concept for the next generation device is described.

  8. Nonlinear dynamics of coiling, and mounding in viscoelastic jets

    NASA Astrophysics Data System (ADS)

    Majmudar, Trushant; Ober, Thomas; McKinley, Gareth

    2009-11-01

    Free surface continuous jets of non-Newtonian fluids, although relevant for many industrial processes like bottle filling, remain poorly understood in terms of fundamental fluid dynamics. Here we present a systematic study of the effect of viscoelasticity on the dynamics of continuous jets of worm-like micellar surfactant solutions of varying viscosities and elasticities, and model yield-stress fluids. We systematically vary the height of the drop and the flow rate in order to study the effects of varying geometric and kinematic parameters. We observe that for fluids with higher elastic relaxation times, folding is the preferred mode. In contrast, for low elasticity fluids we observe complex nonlinear dynamics consisting of coiling, folding, and irregular meandering as the height of the fall increases. Beyond this regime, the jet dynamics smoothly crosses over to exhibit the ``leaping shampoo" or the Kaye effect. Upon increasing the flow rate to very high values, the ``leaping shampoo" state disappears and is replaced by a pronounced mounding or ``heaping". A subsequent increase in the flow rate results in finger-like protrusions to emerge out of the mound and climb up towards the nozzle. This novel transition is currently under investigation and remains a theoretical challenge.

  9. Variety and complexity in the mound of sedimentary rock in Gale Crater, Mars

    NASA Astrophysics Data System (ADS)

    Edgett, K. S.; Malin, M. C.

    2011-12-01

    NASA's Mars Science Laboratory rover, Curiosity, will be used to explore a portion of the lower stratigraphic record of the northwest side of a mound of layered rock ˜5 km thick in the 155 km-diameter Gale Crater. The rock materials are of a sedimentary origin, though the proportions of clastic sediment, tephra, and chemical precipitates are presently unknown. The mound is usually described as having lower and upper units separated by an erosional unconformity. However, some investigators recognize that it is considerably more complex. The stratigraphy displays vertical and lateral complexity; multiple erosional unconformities; filled, buried, interbedded, and exhumed or partly exhumed impact craters; evidence for deposition along the base of the mound followed by retreat of less-resistant rocks and abandonment of erosion-resistant materials shed from the mound; lithified sediments deposited at the mouths of streams that cut mound rock; inversion of intra-canyon stream channel sediment; and widening of canyons. On the northeast side of the mound there are landslide deposits, shed from the mound, that contain large blocks (10s to 100s of m) of layered rock in various orientations. The mound's highest feature does not exhibit layering and has been interpreted by some as being Gale's impact-generated central peak. However, its highest elevation exceeds that of most of the crater rim, an observation inconsistent with central peaks (where they occur at all) in martian craters of diameters similar to Gale. The layered materials that occur highest in the mound are also at elevations that exceed most of the crater rim; these exhibit repeated stratal packages that drape previously-eroded mound topography; they produce boulders as they erode, attesting to their lithified nature and requiring that a lithification process occurred in materials located ≥ 5 km above the deepest part of Gale. The lower mound strata, including the Curiosity field site, are diverse materials

  10. Contaminant exposures at the 4H shell mounds in the Santa Barbara Channel.

    PubMed

    Phillips, Charles R; Salazar, Michael H; Salazar, Sandra M; Snyder, Barry J

    2006-12-01

    Remobilization, bioavailability, and potential toxicity of chemical contaminants were evaluated at the 4H shell mounds - the site of abandoned offshore oil and gas production platforms in the Santa Barbara Channel region of the Southern California Bight. Evaluations used a weight-of-evidence approach based on results from bulk phase chemical analyses and laboratory toxicity testing of shell mound cores, in situ field bioassays using caged mussels, and surficial sediment chemistry. Shell mound cores contained elevated concentrations of metals associated with drilling wastes (e.g., Ba, Cr, Pb, and Zn), as well as monocyclic and polycyclic aromatic hydrocarbons (PAHs). The highest concentrations along with pockets of free oil were associated with the middle "cuttings" stratum. Sediments composited from all core strata caused significant acute toxicity and bioaccumulation of Ba and PAHs in test organisms during laboratory exposures. In contrast, caged mussels placed at each of the shell mounds for a period of 57-58 days had greater than 90% survival, and there were no significant differences in survival of mussels placed at the shell mounds and corresponding reference sites. While all mussel samples exhibited increases in shell length, whole animal weight, and tissue lipid content, in some cases growth metrics for the shell mound mussels were significantly higher than those for the reference sites. Concentrations of metals, PAHs, and polychlorinated biphenyls (PCBs) in tissues of the shell mound mussels were not significantly different from those at reference sites. The presence of labile aromatic hydrocarbons in shell mound cores and absence of significant contaminant accumulation of tissues of caged mussels indicated that chemical contaminants are not being remobilized from the 4H shell mounds. Surficial bottom sediments near the shell mounds contained elevated Ba concentrations that probably were associated with drilling wastes. However, concentrations did not

  11. On the influence of cold-water coral mound size on flow hydrodynamics, and vice versa

    NASA Astrophysics Data System (ADS)

    Cyr, Frédéric; Haren, Hans; Mienis, Furu; Duineveld, Gerard; Bourgault, Daniel

    2016-01-01

    Using a combination of in situ observations and idealistic 2-D nonhydrostatic numerical simulations, the relation between cold-water coral (CWC) mound size and hydrodynamics is explored for the Rockall Bank area in the North Atlantic Ocean. It is shown that currents generated by topographically trapped tidal waves in this area cause large isopycnal depressions resulting from an internal hydraulic control above CWC mounds. The oxygen concentration distribution is used as a tracer to visualize the flow behavior and the turbulent mixing above the mounds. By comparing two CWC mounds of different sizes and located close to each other, it is shown that the resulting mixing is highly dependent on the size of the mound. The effects of the hydraulic control for mixing, nutrient availability, and ecosystem functioning are also discussed.

  12. The nature and origin of Mafic Mound in the South Pole-Aitken Basin

    NASA Astrophysics Data System (ADS)

    Moriarty, Daniel P.; Pieters, Carle M.

    2015-10-01

    "Mafic Mound" is a distinctive and enigmatic feature 75 km across and 1 km high near the center of the vast South Pole-Aitken Basin (SPA). Using several modern data sets, we characterize the composition, morphology, and gravity signature of the structure in order to assess its origin. Mafic Mound is found to exhibit a perched circular depression and a homogeneous high-Ca pyroxene-bearing composition. Several formation hypotheses based on known lunar processes are evaluated, including the possibilities that Mafic Mound represents (1) uplifted mantle, (2) SPA-derived impact melt, (3) a basalt-filled impact crater, or (4) a volcanic construct. Individually, these common processes cannot fully reproduce the properties of Mafic Mound. Instead, we propose a hybrid origin in which Mafic Mound is an edifice formed by magmatic processes induced by the formation and evolution of SPA. This form of nonmare volcanism has not previously been documented on the Moon.

  13. Electromagnetic surveying of seafloor mounds in the northern Gulf of Mexico

    USGS Publications Warehouse

    Ellis, M.; Evans, R.L.; Hutchinson, D.; Hart, P.; Gardner, J.; Hagen, R.

    2008-01-01

    Seafloor controlled source electromagnetic data, probing the uppermost 30 m of seafloor sediments, have been collected with a towed magnetic dipole-dipole system across two seafloor mounds at approximately 1300 m water depth in the northern Gulf of Mexico. One of these mounds was the focus of??a recent gas hydrate research drilling program. Rather than the highly resistive response expected of massive gas hydrate within the confines of the mounds, the EM data are dominated by the effects of raised temperatures and pore fluid salinities that result in an electrically conductive seafloor. This structure suggests that fluid advection towards the seafloor is taking place beneath both mounds. Similar responses are seen at discrete locations away from the mounds in areas that might be associated with faults, further suggesting substantial shallow fluid circulation. Raised temperatures and salinities may inhibit gas hydrate formation at depth as has been suggested at other similar locations in the Gulf of Mexico. ?? 2008 Elsevier Ltd.

  14. Kentucky and Tennessee. Mounds of potential pay in Ft. Payne reef trend

    SciTech Connect

    Bigelow, T.

    1983-06-01

    It is one of the hottest areas in Tennessee. Largely centered in Fentress, Scott and Morgan counties, the Ft. Payne reefs are a series of subsurface mounds, parallel to one another, that seemingly align in a northeast- southwest direction. The mounds are at depths of 1000 to 2500 ft. To the west near the Cincinnati Arch, the mounds are relatively shallow. Whereas to the southeast the mounds downdip at a rate of ca 50 ft/mile toward the Appalachian fold belt. Most activity to date has been in the shallower Ft. Payne. Production varies greatly, from 5 bopd/well to more than 900 bopd/well. There are 21 producing fields in the Ft. Payne, with total production in excess of 6 million bbl. The mounds are of Lower Mississippian age and are thought to have been deposited along a transgressive/regressive shoreline.

  15. Rubble masonry response under cyclic actions: The experience of L'Aquila city (Italy)

    NASA Astrophysics Data System (ADS)

    Fonti, Roberta; Barthel, Rainer; Formisano, Antonio; Borri, Antonio; Candela, Michele

    2015-12-01

    Several methods of analysis are available in engineering practice to study old masonry constructions. Two commonly used approaches in the field of seismic engineering are global and local analyses. Despite several years of research in this field, the various methodologies suffer from a lack of comprehensive experimental validation. This is mainly due to the difficulty in simulating the many different kinds of masonry and, accordingly, the non-linear response under horizontal actions. This issue can be addressed by examining the local response of isolated panels under monotonic and/or alternate actions. Different testing methodologies are commonly used to identify the local response of old masonry. These range from simplified pull-out tests to sophisticated in-plane monotonic tests. However, there is a lack of both knowledge and critical comparison between experimental validations and numerical simulations. This is mainly due to the difficulties in implementing irregular settings within both simplified and advanced numerical analyses. Similarly, the simulation of degradation effects within laboratory tests is difficult with respect to old masonry in-situ boundary conditions. Numerical models, particularly on rubble masonry, are commonly simplified. They are mainly based on a kinematic chain of rigid blocks able to perform different "modes of damage" of structures subjected to horizontal actions. This paper presents an innovative methodology for testing; its aim is to identify a simplified model for out-of-plane response of rubbleworks with respect to the experimental evidence. The case study of L'Aquila district is discussed.

  16. Rubble masonry response under cyclic actions: The experience of L’Aquila city (Italy)

    SciTech Connect

    Fonti, Roberta Barthel, Rainer; Formisano, Antonio; Borri, Antonio; Candela, Michele

    2015-12-31

    Several methods of analysis are available in engineering practice to study old masonry constructions. Two commonly used approaches in the field of seismic engineering are global and local analyses. Despite several years of research in this field, the various methodologies suffer from a lack of comprehensive experimental validation. This is mainly due to the difficulty in simulating the many different kinds of masonry and, accordingly, the non-linear response under horizontal actions. This issue can be addressed by examining the local response of isolated panels under monotonic and/or alternate actions. Different testing methodologies are commonly used to identify the local response of old masonry. These range from simplified pull-out tests to sophisticated in-plane monotonic tests. However, there is a lack of both knowledge and critical comparison between experimental validations and numerical simulations. This is mainly due to the difficulties in implementing irregular settings within both simplified and advanced numerical analyses. Similarly, the simulation of degradation effects within laboratory tests is difficult with respect to old masonry in-situ boundary conditions. Numerical models, particularly on rubble masonry, are commonly simplified. They are mainly based on a kinematic chain of rigid blocks able to perform different “modes of damage” of structures subjected to horizontal actions. This paper presents an innovative methodology for testing; its aim is to identify a simplified model for out-of-plane response of rubbleworks with respect to the experimental evidence. The case study of L’Aquila district is discussed.

  17. Recycling of rubble from building demolition for low-shrinkage concretes.

    PubMed

    Corinaldesi, Valeria; Moriconi, Giacomo

    2010-04-01

    In this project concrete mixtures were prepared that were characterized by low ductility due to desiccation by using debris from building demolition, which after a suitable treatment was used as aggregate for partial replacement of natural aggregates. The recycled aggregate used came from a recycling plant, in which rubble from building demolition was selected, crushed, cleaned, sieved, and graded. Such aggregates are known to be more porous as indicated by the Saturated Surface Dry (SSD) moisture content. The recycled concrete used as aggregates were added to the concrete mixture in order to study their influence on the fresh and hardened concrete properties. They were added either after water pre-soaking or in dry condition, in order to evaluate the influence of moisture in aggregates on the performance of concrete containing recycled aggregate. In particular, the effect of internal curing, due to the use of such aggregates, was studied. Concrete behavior due to desiccation under dehydration was studied by means of both drying shrinkage test and German angle test, through which shrinkage under the restrained condition of early age concrete can be evaluated. PMID:20022737

  18. System for producing a uniform rubble bed for in situ processes

    DOEpatents

    Galloway, Terry R.

    1983-01-01

    A method and a cutter for producing a large cavity filled with a uniform bed of rubblized oil shale or other material, for in situ processing. A raise drill head (72) has a hollow body (76) with a generally circular base and sloping upper surface. A hollow shaft (74) extends from the hollow body (76). Cutter teeth (78) are mounted on the upper surface of the body (76) and relatively small holes (77) are formed in the body (76) between the cutter teeth (78). Relatively large peripheral flutes (80) around the body (76) allow material to drop below the drill head (72). A pilot hole is drilled into the oil shale deposit. The pilot hole is reamed into a large diameter hole by means of a large diameter raise drill head or cutter to produce a cavity filled with rubble. A flushing fluid, such as air, is circulated through the pilot hole during the reaming operation to remove fines through the raise drill, thereby removing sufficient material to create sufficient void space, and allowing the larger particles to fill the cavity and provide a uniform bed of rubblized oil shale.

  19. System for producing a uniform rubble bed for in situ processes

    DOEpatents

    Galloway, T.R.

    1983-07-05

    A method and a cutter are disclosed for producing a large cavity filled with a uniform bed of rubblized oil shale or other material, for in situ processing. A raise drill head has a hollow body with a generally circular base and sloping upper surface. A hollow shaft extends from the hollow body. Cutter teeth are mounted on the upper surface of the body and relatively small holes are formed in the body between the cutter teeth. Relatively large peripheral flutes around the body allow material to drop below the drill head. A pilot hole is drilled into the oil shale deposit. The pilot hole is reamed into a large diameter hole by means of a large diameter raise drill head or cutter to produce a cavity filled with rubble. A flushing fluid, such as air, is circulated through the pilot hole during the reaming operation to remove fines through the raise drill, thereby removing sufficient material to create sufficient void space, and allowing the larger particles to fill the cavity and provide a uniform bed of rubblized oil shale. 4 figs.

  20. Effigy mound sites as cultural landscapes: A geophysical spatial analysis of two Late Woodland sites in southeastern Wisconsin

    NASA Astrophysics Data System (ADS)

    Kaufmann, Kira E.

    This dissertation is a spatial analysis of a class of sacred sites known as Effigy Mounds during the Late Woodland period in southeast Wisconsin, circa A.D. 700--1100. Effigy Mounds are earthworks in the shape of animals, conical, linear, or geometric shapes. The research is focused on the upper Rock River Drainage in southern Wisconsin, a region where Effigy Mounds are very common. Although there are many theories concerning the meanings of Effigy Mounds, there is no cohesive description of Effigy Mounds as landscape elements and their function in the use of space by Late Woodland people. This research connects cultural and cognitive aspects of Native American cosmology with physical manifestations on the landscape. Effigy Mounds are examined from ideological and physical perspectives that are not mutually exclusive. Effigy Mounds are viewed as signifiers with multiple levels of function and meaning including sacred space, territorial markers, and mechanisms of social control and cohesion. Investigation at two Late Woodland Effigy Mound sites, Indian Mounds County Park in Jefferson County and Nitschke Mounds County Park in Dodge County, shows that landscape utilization varied significantly within and among Effigy Mound sites. An alternative model to understand Late Woodland Effigy Mound sites as ritual landscapes explores these features, their distribution across space, and the connection to internal site structures by synthesizing multidisciplinary data from historical ethnographic accounts, previous archaeological surveys, and new geophysical data. This multidisciplinary approach provides an example applicable to other landscape studies.

  1. Elimination of the Mound-Building Termite, Nasutitermes exitiosus (Isoptera: Termitidae) in South-Eastern Australia Using Bistrifluron Bait.

    PubMed

    Webb, Garry A; Mcclintock, Charles

    2015-12-01

    Bistrifluron, a benzoylphenylurea compound, was evaluated for efficacy against Nasutitermes exitiosus (Hill), a mound-building species in southern Australia. Bistrifluron bait (trade name Xterm) was delivered as containerized pellets inserted into plastic feeding stations implanted in the sides of mounds-60 g for bistrifluron bait-treated mounds and 120 g of blank bait for untreated mounds. Termites actively tunneled in the gaps between pellets and removed bait from the canisters. All five treated mounds were eventually eliminated, and all five untreated mounds remained active at the end of the trial. Four of the five treated mounds were considered dead and excavated after 26 wk, but there were earlier signs of mound distress-reduced repair of experimental casement damage and reduced activity in bait canisters by 22 wk and reduced internal mound temperature after 11 wk. One treated mound showed activity in the bait station right through until almost the end of the trial (47 wk), but excavation at 49 wk showed no further activity in the mound. The five untreated colonies removed on average 97% of blank bait offered, while the five treated colonies removed on average 39.1% of bait offered. There was a wide variation in temperature profiles of mounds (up to 15°C for both minimum and maximum internal temperatures), from the beginning of the trial and even before the effects of baiting were evident. PMID:26470378

  2. Transition and Closeout of the Former DOE Mound Plant Site: Lessons Learned

    SciTech Connect

    Carpenter, C. P.; Marks, M. L.; Smiley, S.L.; Gallaher, D. M.

    2006-07-01

    The U.S. Department of Energy's (DOE's) Office of Environmental Management (EM) manages the Miamisburg Closure Project (MCP) by cleaning up the Mound site, located in Miamisburg, Ohio, to specific environmental standards, conveying all excess land parcels to the Miamisburg Mound Community Improvement Corporation, and transferring all continuing DOE post-closure responsibilities to the Office of Legacy Management (LM). Presently, the EM cleanup contract of the Mound site with CH2M Hill Mound Inc. is scheduled for completion on March 31, 2006. LM manages the Mound transition efforts and also post-closure responsibilities at other DOE sites via a contract with the S.M. Stoller Corporation. The programmatic transfer from EM to LM is scheduled to take place on October 1, 2006. The transition of the Mound site has required substantial integration and coordination between the EM and LM. Several project management principles have been implemented to help facilitate the transfer of programmatic responsibility. As a result, several lessons learned have been identified to help streamline and improve integration and coordination of the transfer process. Lessons learned from the Mound site transition project are considered a work in progress and have been summarized according to a work breakdown structure for specific functional areas in the transition schedule. The functional areas include program management, environmental, records management, information technology, property management, stakeholder and regulatory relations, procurement, worker pension and benefits, and project closeout. Specific improvements or best practices have been recognized and documented by the Mound transition team. The Mound site is one of three major cleanup sites within the EM organization scheduled for completion in 2006. EM, EM cleanup contractor, LM, and LM post-closure contractor have identified lessons learned during the transition and closure of the Mound site. The transition effort from

  3. A Biomechanical Comparison of Pitching From a Mound Versus Flat Ground in Adolescent Baseball Pitchers

    PubMed Central

    Nissen, Carl W.; Solomito, Matthew; Garibay, Erin; Õunpuu, Sylvia; Westwell, Melany

    2013-01-01

    Background: Baseball professionals believe that pitching from a mound can increase the stresses placed on the body. Hypothesis: There is no difference in kinematics or kinetics in pitching from a mound versus flat-ground conditions in adolescent baseball pitchers. Study Design: Laboratory investigation. Methods: The fastball pitching motions of 15 adolescent baseball pitchers, including upper extremity kinematics and kinetics and lead- and trail-leg kinematics, were evaluated while pitching from the mound and flat ground. Student t tests were used to determine the differences between the 2 testing conditions. Results: Maximum external glenohumeral rotation was similar between the 2 conditions (134° ± 14° mound vs 133° ± 14° flat ground, P = 0.10). Ankle plantar flexion of the lead leg at ball release was greater in the flat-ground condition (−20° ± 10° mound vs −15° ± 12° flat ground, P = 0.01). A statistically significant increase in glenohumeral internal rotation moment (33.6 ± 12.1 Nm mound vs 31.7 ± 11.6 Nm flat ground, P = 0.01) and an increase in elbow varus moment (33.3 ± 12.3 Nm mound vs 31.4 ± 11.8 Nm flat ground, P = 0.02) was measured when pitching from the mound as compared with flat ground. Conclusion: Pitching from the mound causes increased stress on the shoulder and elbow of adolescent pitchers as compared with that from flat ground. Clinical Relevance: The differences in kinematics as well as increased moments in the shoulder and elbow are helpful for pitchers and their coaches to know at the beginning of their season or as they return from injury or surgery. Pitchers in these situations should start their pitching progression on flat ground and progress to the mound. PMID:24427428

  4. COCARDE - a research platform for a new look to ancient mounds

    NASA Astrophysics Data System (ADS)

    Rüggeberg, Andres; Henriet, Jean-Pierre; Foubert, Anneleen; van Rooij, David; Samankassou, Elias; Dullo, Wolf-Christian; Spezzaferri, Silvia; Science Community, Cocarde

    2010-05-01

    Carbonate mounds are important contributors of life in different settings, from warm-water to cold-water environments, and throughout geological history. Research on modern carbonate mounds over the last years made a major contribution to our overall understanding of these particular sedimentary systems. By looking to the modern carbonate mound community, some fundamental questions could be addressed, until now not yet explored in fossil mound settings. The international network COCARDE (Cold-Water Carbonate Reservoir Systems in Deep Environment) is a platform for exploring new insights in cold- and warm-water carbonate mound research of recent and ancient mound systems (http://www.cocarde.eu). One aim of the COCARDE network is to bring scientific communities together, to study recent carbonate mounds in midslope environments in the present ocean, and to investigate fossil mounds spanning the whole Phanerozoic time. Scientific challenges on modern and ancient carbonate mound systems got already well defined during two dedicated workshops of the COCARDE network: 1) the ESF Magellan COCARDE Workshop in Fribourg, Switzerland, January 21-24, 2009, and 2) the ESF MiCROSYSTEMS - FWO COCARDE Flanders - ESF CHECREEF Workshop and Field Seminar, Oviedo, Spain, September 16-20, 2009. The wide spectrum of disciplines in geosciences and biology are summarized in the following five topics for the carbonate mound research: i) Palaeoenvironment; ii) The Microbial Filter; iii) Petrophysical Characterization; iv) Connectivity and Compartmentalization - the Fluid System; v) Advancing our Insight in Phanerozoic Reef Systems - the Slope Niche. One of the most important outcomes of these meetings was the identification of the need for combined research efforts on fossil and modern carbonate settings to provide the baseline reference standard for a better understanding of these exceptional systems and their potential as hydrocarbon reservoirs.

  5. Hydrographic Conditions At The Carbonate Mound Locations In The NE Atlantic

    NASA Astrophysics Data System (ADS)

    van Weering, T.; de Hass, H.; White, M.; de Stigter, H.

    As part of the component 5th framework projects that form part of the OMARC clus- ter, hydrographic measurements have been made in the region of the deep water car- bonate mounds provinces of the NE Atlantic. These mounds are located at depths 600-1000m depth along the continental slopes of the Porcupine Sea Bight and Bank and the SE Rockall Bank. These regions correspond to the vertical and horizontal boundaries of the intermediate water masses that occupy the region, providing differ- ent hydrographic regimes between mound locations,. In addition there is a large vari- ability in temperature/salinity conditions and both characteristics have implications for the distribution of mound fauna. The deep water coral associated with carbonate mound structures coincide with strong benthic current activity and this is confirmed from benthic current measurements from landers and current meters at the SE Rockall and NW Porcupine Bank mound loca- tions. Near seabed currents are strong, with a typical mean speed of 20cm/s and a max- imum in excess of 50cm/s. At the SE Rockall Bank site, a mean SW along isobath flow is measured, whilst at the NW Porcupine mound location, a poleward slope current is measured. Bottom Ekman dynamics is apparent with a changes in near seabed verti- cal stratification related to changes to overlying slope current strength. Strong diurnal variability is found at the Rockall Bank site, providing strong cross-slope currents. The diurnal current forcing over both the Rockall and Porcupine Banks may result in enclosed circulation patterns over the banks and retention of organic material supplied to the mounds. In contrast, currents at the Hovland and Magellan mound sites in the northern Porcupine Sea Bight, where there are numerous buried mounds, are relatively low.

  6. Methane oxidation by termite mounds estimated by the carbon isotopic composition of methane

    NASA Astrophysics Data System (ADS)

    Sugimoto, Atsuko; Inoue, Tetsushi; Kirtibutr, Nit; Abe, Takuya

    1998-12-01

    Emission rates and carbon isotope ratios of CH4, emitted by workers of termites, and of CH4, emitted from their mounds, were observed in a dry evergreen forest in Thailand to estimate the proportion of CH4 oxidized during emission through the mound. The δ13C of CH4 emitted from a termite mound (-70.9 to -82.4‰) was higher than that of CH4 emitted by workers in the mound (-85.4 to -97. l‰). Using a fractionation factor (a = 0.987) for oxidation of CH4 which was obtained in the incubation experiment, an emission factor defined as (CH4 emitted from a termite mound/CH4 produced by termites) was calculated. The emission factor obtained in each termite mound was nearly zero for Macrotermes (fungus-growing termites), of which the nest has a thick soil wall and subterrannean termites, and 0.17 to 0.47 for Termitinae (small-mound-making termites). Global CH4 emission by termites was estimated on the basis of the CH4 emission rates by workers and termite biomass with the emission factors. The calculated result was 1.5 to 7.4 Tg/y (0.3 to 1.3% of total source), which is considerably smaller than the estimate by the IPCC [1994].

  7. Ground-squirrel mounds and related patterned ground along the San Andreas Fault in Central California

    USGS Publications Warehouse

    Wallace, Robert E.

    1991-01-01

    Extensive areas of mound topography and related patterned ground, apparently derived from the mounds of the California Ground Squirrel (Spermophilus beecheyi beecheyi), are in central California.  The relation of patterned ground to the San Andreas fault west of Bakersfield may provide insight into the timing of deformation along the fault as well as the history of ground squirrels.  Mound topography appears to have evolved through several stages from scattered mounds currently being constructed on newly deposited alluvial surfaces, to saturation of areas by mounds, followed by coalescence, elongation and lineation of the mounds.  Elongation, coalescence and modification of the mounds has been primarily by wind, but to a lesser extent by drainage and solifluction.  A time frame including ages of 4,000, 10,500, 29,000, and 73,000 years BP is derived by relating the patterns to slip on the San Andreas fault.  Further relating of the patterns to faulting, tilting, and warping may illuminate details of the rates and history of deformation.  Similarly, relating the patterns to the history of ground squirrel activity may help answer such problems as rates of dispersal and limits on population density.

  8. Composition of seismically identified satellite mounds surrounding Greater Aneth field, southeast Utah

    SciTech Connect

    Eby, D.E. ); Groen, W.G.; Johnson, J.F. )

    1993-08-01

    Five different types of satellite mounds have been encountered during drilling and extensive coring of approximately 40 high-resolution CDP (common depth point) seismic anomalies in the Desert Creek interval of the Pennsylvanian (Desmoinesian) Paradox Formation around the periphery of Greater Aneth field. The composition and diagenetic modification of these mound types directly affect the quality of porosity and permeability within each satellite buildup. The mound types and their principal characteristics are (1) crinoid-sponge limestone with wackestone to packstone fabrics; (2) coralline algal boundstones that are slightly dolomitized; (3) bryozoan-dominated lime boundstones with no significant dissolution porosity; (4) phylloid algal bafflestones with extensive dissolution and some dolomitization occasionally overlain by dolomitized stromatolitic/thrombolitic boundstones; and (5) stacked bioclastic grainstones with extensive dissolution and complete dolomitization. Controls on the development of each mound type appear to be a function of water depth and prevailing water energy. Mound types 1 and 2 typically have low porosity, whereas type 3 preserved primary porosity. Types 4 and 5 commonly exhibit extensive porosity and permeability modification through freshwater dissolution and early dolomitization. Up to five cycles of buildup growth can occur within the Desert Creek satellite mounds. Mound composition types will recur or change to another growth type depending upon local water depth and energy conditions. Calibration of seismic amplitude variations can be used in imaging reservoir size and porosity variation.

  9. Evaporation from Banksia woodland on a groundwater mound

    NASA Astrophysics Data System (ADS)

    Farrington, P.; Greenwood, E. A. N.; Bartle, G. A.; Beresford, J. D.; Watson, G. D.

    1989-01-01

    Annual evaporation from a site within a Banksia woodland on a groundwater mound near Perth, Western Australia, was estimated from measurements of daily evaporation by ventilated chambers on fourteen occasions during a 12-month period. The total evaporation for this period was estimated to be 666 mm (77% of annual rainfall). About two-thirds of the total evaporation came from the ground flora, one-fifth from Banksia trees, and the remainder from the tall shrub Adenanthos cygnorum. Depth to water table, which ranged from 4 to 12 m over the site, had little effect on total evaporation. This work suggests that regular reduction in ground flora foliage, for example, by controlled burning could increase recharge.

  10. Three-dimensional potential flow over hills and oval mounds

    NASA Technical Reports Server (NTRS)

    Siegel, R.

    1976-01-01

    An analysis was made of the potential flow behavior for an initially uniform flow passing over a single axisymmetric hill, an oval mound, and a combination of two hills. Small perturbation theory was used, and the resulting Laplace equation for the perturbation velocity potential was solved by using either a product solution or a Green's function. The three dimensional solution is of interest in calculating the pressure distribution around obstacles, the flow of pollutants carried by the wind, and the augmentation of wind velocity for windmill siting. The augmentation in velocity at the top of a hill was found to be proportional to the hill height relative to a characteristic width dimension of the hill. An axisymmetric hill produced about 20 percent less velocity increase than a two dimensional ridge having the same cross-sectional profile.

  11. Microseismic Monitoring of the Mounds Drill Cuttings Injection Tests

    SciTech Connect

    Branagan, P.T.; Mahrer, K.D.; Moschovidis, Z.A.; Warpinski, N.R.; Wolhart, S.L.

    1999-01-25

    This paper describes the microseismic mapping of repeated injections of drill cuttings into two separate formations at a test site near Mounds, OK. Injections were performed in sandstone and shale formations at depths of 830 and 595 m, respectively. Typical injection disposal was simulated using multiple small-volume injections over a three-day period, with long shut-in periods interspersed between the injections. Microseismic monitoring was achieved using a 5-level array of wireline-run, triaxial- accelerometer receivers in a monitor well 76 m from the disposed well. Results of the mapped microseismic locations showed that the disposal domti W= generally aligns with the major horizontal stress with some variations in azimuth and that wide variations in height and length growth occurred with continued injections. These experiments show that the cuttings injection process cm be adequately monitored from a downhole, wireline-run receiver array, thus providing process control and environmental assurance.

  12. Low-speed impacts between rubble piles modeled as collections of polyhedra

    NASA Astrophysics Data System (ADS)

    Korycansky, D. G.; Asphaug, Erik

    2006-04-01

    We present results of modeling rubble piles as collections of polyhedra. The use of polyhedra allows more realistic (irregular) shapes and interactions (e.g. collisions), particularly for objects of different sizes. Rotational degrees of freedom are included in the modeling, which may be important components of the motion. We solved the equations of rigid-body dynamics, including frictional/inelastic collisions, for collections of up to several hundred elements. As a demonstration of the methods and to compare with previous work by other researchers, we simulated low-speed collisions between km-scale bodies with the same general parameters as those simulated by Leinhardt et al. [Leinhardt, Z.M., Richardson, D.C., Quinn, T., 2000. Icarus 146, 133-151]. High-speed collisions appropriate to present-day asteroid encounters require additional treatment of shock effects and fragmentation and are the subject of future work; here we study regimes appropriate to planetesimal accretion and re-accretion in the aftermath of catastrophic events. Collisions between equal-mass objects at low speeds ( <10 cms) were simulated for both head-on and off-center collisions between rubble piles made of a power-law mass spectrum of sub-elements. Very low-speed head-on collisions produce single objects from the coalescence of the impactors. For slightly higher speeds, extensive disruption occurs, but re-accretion produces a single object with most of the total mass. For increasingly higher speeds, the re-accreted object has smaller mass, finally resulting in complete catastrophic disruption with all sub-elements on escape trajectories and only small amounts of mass in re-accreted bodies. Off-center collisions at moderately low speeds produce two re-accreted objects of approximately equal mass, separating at greater than escape speed. At high speed, complete disruption occurs as with the high-speed head-on collisions. Head-on collisions at low to moderate speeds result in objects of mostly

  13. Cumulative Damage in Strength-Dominated Collisions of Rocky Asteroids: Rubble Piles and Brick Piles

    NASA Technical Reports Server (NTRS)

    Housen, Kevin

    2009-01-01

    Laboratory impact experiments were performed to investigate the conditions that produce large-scale damage in rock targets. Aluminum cylinders (6.3 mm diameter) impacted basalt cylinders (69 mm diameter) at speeds ranging from 0.7 to 2.0 km/s. Diagnostics included measurements of the largest fragment mass, velocities of the largest remnant and large fragments ejected from the periphery of the target, and X-ray computed tomography imaging to inspect some of the impacted targets for internal damage. Significant damage to the target occurred when the kinetic energy per unit target mass exceeded roughly 1/4 of the energy required for catastrophic shattering (where the target is reduced to one-half its original mass). Scaling laws based on a rate-dependent strength were developed that provide a basis for extrapolating the results to larger strength-dominated collisions. The threshold specific energy for widespread damage was found to scale with event size in the same manner as that for catastrophic shattering. Therefore, the factor of four difference between the two thresholds observed in the lab also applies to larger collisions. The scaling laws showed that for a sequence of collisions that are similar in that they produce the same ratio of largest fragment mass to original target mass, the fragment velocities decrease with increasing event size. As a result, rocky asteroids a couple hundred meters in diameter should retain their large ejecta fragments in a jumbled rubble-pile state. For somewhat larger bodies, the ejection velocities are sufficiently low that large fragments are essentially retained in place, possibly forming ordered "brick-pile" structures.

  14. Coral-rubble ridges as dynamic coastal features - short-term reworking and weathering processes

    NASA Astrophysics Data System (ADS)

    Spiske, Michaela

    2016-02-01

    A coral-rubble ridge built by storm waves at Anegada (British Virgin Islands) underwent remarkable changes in shape and weathering in a 23-month period. The ridge is located along the island's north shore, in the lee of a fringing reef and a reef flat. This coarse-clast ridge showed two major changes between March 2013, when first examined, and February 2015, when revisited. First, a trench dug in 2013, and intentionally left open for further examination, was found almost completely infilled in 2015, and the ridge morphology was modified by slumping of clasts down the slope and by reworking attributable to minor storm waves. In size, composition and overall condition, most of the clasts that filled the trench resemble reworked clasts from the ridge itself; only a small portion had been newly brought ashore. Second, a dark gray patina formed on the whitish exteriors of the carbonate clasts that had been excavated in 2013. These biologically weathered, darkened clasts had become indistinguishable from clasts that had been at the ridge surface for a much longer time. The findings have two broader implications. First, coastal coarse-clast ridges respond not solely to major storms, but also to tropical storms or minor hurricanes. The modification and reworking of the ridge on Anegada most probably resulted from hurricane Gonzalo which was at category 1-2 as it passed about 60 km north of the island in October 2014. Second, staining of calcareous clasts by cyanobacteria in the supralittoral zone occurs within a few months. In this setting, the degree of darkening quickly saturates as a measure of exposure age.

  15. Residual indoor contamination from world trade center rubble fires as indicated by polycyclic aromatic hydrocarbon profiles.

    PubMed

    Pleil, Joachim D; Funk, William E; Rappaport, Stephen M

    2006-02-15

    The catastrophic destruction of the World Trade Center (WTC) on Sept. 11, 2001 (9/11) created an immense dust cloud followed by fires that emitted smoke and soot into the air of New York City (NYC) well into December. Outdoor pollutant levels in lower Manhattan returned to urban background levels after about 200 days as the fires were put out and the debris cleanup was completed. However, particulate matter (PM) from the original collapse and fires also penetrated into commercial and residential buildings. This has created public concern because WTC dust is thought to cause adverse pulmonary symptoms including "WTC cough" and reduced lung capacity. Additionally, some recent studies have suggested a possible link between exposure to WTC contamination and other adverse health effects. Distinguishing between normal urban pollutant infiltration and residual WTC dust remaining in interior spaces is difficult; efforts are underway to develop such discriminator methods. Some progress has been made in identifying WTC dust by the content of fibers believed to be associated with the initial building collapse. There are also contaminants created by the fires that burned for 100 days in the debris piles of the building rubble. Using WTC ambient air samples, we have developed indicators for fire related PM based on the relative amounts of specific particle bound polycyclic aromatic hydrocarbons (PAHs) and the mass fraction of PAHs per mass of PM. These two parameters are combined, and we show a graphical method for discriminating between fire sources and urban particulate sources as applied to samples of settled dusts. We found that our PAHs based discriminator method can distinguish fire source contributions to WTC related particulate matter and dusts. Other major building fires or large open burn events could have similar PAHs characteristics. We found that random samples collected approximately 3.5 years after the WTC event from occupied indoor spaces (primarily residential

  16. Surgical anatomy of the midcheek and malar mounds.

    PubMed

    Mendelson, Bryan C; Muzaffar, Arshad R; Adams, William P

    2002-09-01

    The anatomy of the midcheek has not been satisfactorily described to adequately explain midcheek aging and malar mounds, nor has it suggested a logical approach to their correction or provided sufficient detail for safe surgery in this area. This cadaver study, which was complemented by many operative dissections, located a missing link: a glide plane space overlying the body of the zygoma. The space functions to allow mobility of the orbicularis oculi, where it overlies the zygoma and the origins of the elevator muscles to the upper lip. The space is a cleft between the sub-orbicularis oculi fat and the preperiosteal fat and is lined by a fine membrane. The anatomic boundaries are clearly defined by retaining ligaments, which correlate with the triangularity of the space. Several anatomic features provide the functional characteristics of the prezygomatic space, including the (1) absence of direct attachments between the orbicularis in the roof to the floor, (2) more rigid inferior boundary formed by the zygomatic ligaments, and (3) more mobile upper ligamentous boundary formed by the orbicularis retaining ligament (separating from the preseptal space of the lower lid). These components determine the characteristic aging changes that occur in this region and explain much about malar mounds. An appreciation of this anatomy has several surgical implications. The prezygomatic space is a junction area that can be approached from the temple, lower lid, and cheek. The zygomatic branches of the facial nerve to the orbicularis do not cross the space; rather, they course in the walls and in the sub-orbicularis fat within the roof of the space. PMID:12172155

  17. Subtidal eelgrass/macroalgae surveys for the proposed breakwaters at the US Coast Guard Station at Ediz Hook, Washington, March 1993

    SciTech Connect

    Shreffler, D.K.

    1993-05-01

    In 1993, the US Coast Guard proposed to construct two breakwaters and a debris boom to protect its existing pier and moored vessels inside Ediz Hook in Port Angeles Harbor, Washington. To assist the US Army Corps of Engineers -- Seattle District in determining the potential environmental impacts of the proposed breakwaters, Battelle/Marine Sciences Laboratory performed subtidal SCUBA surveys as specified in the Washington Department of Fisheries intermediate eelgrass/macroalgae habitat survey guidelines. The objectives of the subtidal surveys were to (1) quantify the shoot densities of eelgrass; (2) provide percent cover estimates for non-eelgrass macroalgae species; (3) develop a site map indicating the qualitative distribution of eelgrass/macroalgae species, substrate characterization, approximate depth contours, and the approximate location of the proposed project features; and (4) document the time and date of the surveys, turbidity/visibility, presence of invertebrate/vertebrate species, and anecdotal observations pertinent to habitat characterization of the project site. A total of 14 dives along 12 transects (T1--T12) were successfully completed between March 15 and March 17, 1993. Eelgrass was observed on all of the transects except T7 and T8 at the western debris barrier and T12 along the waterward margin of the existing T-pier. The vicinity of the proposed east breakwater had the highest eelgrass shoot densities (up to 89 shoots/m{sup 2}) observed by the divers. Macroalgae and invertebrate species diversity were also highest at the east breakwater site. The low eelgrass densities observed at the west debris barrier site (0 to 14 shoots/m{sup 2}) can be attributed mostly to the lack of suitable substrate. The existing layer of wood debris armoring the bottom at the west project site currently limits, and in the areas of heaviest deposition probably precludes, the growth of eelgrass. As was expected, no eelgrass was observed at the south breakwater site.

  18. Deep sea corals and carbonate mounds of the nw european margin: a biogeochemical perspective

    NASA Astrophysics Data System (ADS)

    Kiriakoulakis, K.; White, M.; Bett, B.; Wolff, G. A.

    2003-04-01

    The deep-sea, scleractinian, reef-forming coral Lophelia pertusa is widespread along the NW European Continental Margin and its presence has been documented since the 19th century. However little is known about its ecology, biochemistry and particularly its relationship with the carbonate mounds it is often associated with. The characterisation of particulate organic matter (POM), which fuels the Lophelia pertusa ecosystems and the sediments on and around the coral/mound sites, may potentially shed light on the biogeochemical processes of the deep water coral (DWC) ecosystems. In this study, POM (20--40 m above bottom) and sediments have been collected from five mound/coral sites along the European Continental Slope (water depth ˜500--1000 m) with distinct oceanographic and sedimentological conditions, (Darwin, Logachev, Pelagia, Hovland and Belgica Mounds located around the Rockall Trough and Porcupine Seabight). Coral densities and mound sizes, shapes and conditions vary significantly from site to site. POM at these sites are significantly different, particularly with respect to the lipid concentrations relative to organic carbon, which are much higher at the Darwin Mounds (N.Rockall Trough; ˜1000m depth) than the rest of the sites (46.63 -- 225.11 mg g-1 and 0.49 -- 14.21 mg g-1 respectively). Polyunsaturated fatty acids (PUFAs), which are used as proxies of labile organic matter are also abundant at the Darwin Mounds, indicating that POM is 'fresh'. Scanning electron microscopy carried out on filtered material from this area confirms this. These mounds are affected by a branch of the poleward slope current, which, in combination with enhanced Ekman downwelling, could transport appreciable amounts of high quality organic matter to the depth that they are found. Lipid (including PUFAs) concentrations at the Pelagia Mounds (SE Rockall Trough; ˜700 m) although lower than at the Darwin Mounds are higher than at the other sites. This location is also influenced by

  19. [Flora Differentiation among Local Ecotopes in the Transzonal Study of Forest-Steppe and Steppe Mounds].

    PubMed

    Lisetskii, F N; Sudnik-Wojcikowska, B; Moysiyenko, I I

    2016-01-01

    Flora similarity was assessed using complete floristic lists of five ecotopes in each of four mounds along the transect from meadow steppes to desert steppes. It was found that the circumapical similitude of floras is more significant than the expositional similitude. Soil analysis in separate ecotopes showed that regular changes in the biogeochemical features are manifested along the topographic gradient and under the effect of the insolation exposure of slopes in local (mound) ecosystems. It was noted that the slopes are characterized by the most abundant steppe vegetation classes in the phytosociological spectrum of mound ecotopes. PMID:27396182

  20. Late Maastrichtian chalk mounds, Stevns Klint, Denmark — Combined physical and biogenic structures

    NASA Astrophysics Data System (ADS)

    Anderskouv, Kresten; Damholt, Tove; Surlyk, Finn

    2007-08-01

    Upper Maastrichtian chalk exposed at the Sigerslev quarry, Stevns Klint, Denmark is characterized by wavy and mound-like bedding geometries outlined by bands of black flint nodules. Four morphological elements are recognized, although bedding geometries are highly variable: southward migrating mounds, eastward migrating mounds, chalk waves and evenly bedded chalk. The mounds are interpreted as having been formed by currents carrying fine-grained suspended sediment which was primarily deposited on the up-current mound flanks. Bryozoans were prolific on the up-current flanks and mound summits, which stabilized the mounds, increased bed roughness and the overall accumulation rate. However, accumulation thicknesses do not correlate consistently with bryozoan density. The bryozoans were therefore important for the formation of the mounds, but the distribution of bryozoans did not solely determine depositional thickness across a mound and thus mound growth pattern. Relatively long wavelength wavy-bedded chalk show gentle convex-up geometries and would probably be described as sediment waves if recognized in seismic sections. The chalk waves were deposited under weaker current velocities than those active during mound formation. The exposed succession is topped by more evenly bedded chalk which was deposited by quiet pelagic fall-out of fine-grained material. The whole succession was deposited on the upper part of the northern flank of a large WNW-ESE trending 3 km wide depositional ridge with an amplitude of 35-40 m formed by contour-parallel WNW-ward flowing bottom currents. The mounds may have been deposited by regional bottom currents, or by spill-over currents from the valley south of the large ridge. The succession was deposited during varying bottom current intensities and the depositional architecture indicates a complex and dynamic environment. The depositional style seems to be controlled by the interplay and relative importance of two end-member processes

  1. Indigenous utilization of termite mounds and their sustainability in a rice growing village of the central plain of Laos

    PubMed Central

    2011-01-01

    Background The objective of this study was to investigate the indigenous utilization of termite mounds and termites in a rain-fed rice growing village in the central plain of Laos, where rice production is low and varies year-to-year, and to assess the possibility of sustainable termite mound utilization in the future. This research was carried out from 2007 to 2009. Methods The termites were collected from their mounds and surrounding areas and identified. Twenty villagers were interviewed on their use of termites and their mounds in the village. Sixty-three mounds were measured to determine their dimensions in early March, early July and middle to late November, 2009. Results Eleven species of Termitidae were recorded during the survey period. It was found that the villagers use termite mounds as fertilizer for growing rice, vegetable beds and charcoal kilns. The villagers collected termites for food and as feed for breeding fish. Over the survey period, 81% of the mounds surveyed increased in volume; however, the volume was estimated to decrease by 0.114 m3 mound-1 year-1 on average due to several mounds being completely cut out. Conclusion It was concluded that current mound utilization by villagers is not sustainable. To ensure sustainable termite utilization in the future, studies should be conducted to enhance factors that promote mound restoration by termites. Furthermore, it will be necessary to improve mound conservation methods used by the villagers after changes in the soil mass of mounds in paddy fields and forests has been measured accurately. The socio-economic factors that affect mound utilization should also be studied. PMID:21849087

  2. Developing a Planting Medium from Solid Waste Compost and Construction and Demolition Rubble for Use in Quarry Rehabilitation

    NASA Astrophysics Data System (ADS)

    Assaf, E. A.

    2015-12-01

    The combination of construction, demolition and excavation (CDE) waste along with the increase in solid waste generation has put a major stress on Lebanon and on the management of its solid waste. Compounding this problem are the issues of quarries closure and rehabilitation and a decrease in forest and vegetative cover. This research aims to provide an integrated solution to the stated problem by developing a "soil mix" derived from a mélange of the organic matter of the solid waste (compost), the CDE waste, and soil. Excavation and construction debris were ground to several sizes and mixed with compost and soil at different ratios. Replicates of these mixes and a set of control (regular soil) were used. In this mix, native and indicator plants are planted (in pots). The plant species used are Mathiolla crassifolia and Zea mays (Corn). Results have shown successful growth of both corn and Mathiolla seedlings in the mixes with higher amounts of construction rubble and compost i.e. Rubble: Soil: Compost Ratio of 2:1:1 and 1:0:1. However treatments with no compost and with less quantities of rubble demonstrated the inability of the soil used to sustain plant growth alone (1:1:1 and 1:1:0). Last but not least, the control consisting of soil only ended up being the weakest mix with yellow corn leaves and small Mathiolla seedlings fifty days after planting and fertilizing. Additionally, soil analysis, rubble and compost analysis were conducted. The samples were tested for heavy metals, nutrient availability and values of pH and EC. No contamination has been reported and an abundance of macronutrients and micronutrients was documented for the soil and compost. High alkalinity is due to the presence of concrete and the high percentage of Calcium Carbonate in Lebanese soils. Accordingly, the most adequate mixes for planting are treatments A (2:1:1) and B (1:0:1) and they should be pursued for a pilot scale study to test their potential use in quarry rehabilitation and

  3. Sedimentary Mounds on Mars: Tracing Present-day Formation Processes into the Past

    NASA Technical Reports Server (NTRS)

    Niles, P. B.; Michalski, J.; Edwards, C. S.

    2014-01-01

    High resolution photography and spectroscopy of the martian surface (MOC, HiRISE) from orbit has revolutionized our view of Mars with one and revealed spectacular views of finely layered sedimentary materials throughout the globe [1]. Some of these sedimentary deposits are 'mound' shaped and lie inside of craters (Fig 1). Crater mound deposits are found throughout the equatorial region, as well as ice-rich deposits found in craters in the north and south polar region [2-4]. Despite their wide geographical extent and varying volatile content, the 'mound' deposits have a large number of geomorphic and structural similarities that suggest they formed via equivalent processes. Thus, modern depositional processes of ice and dust can serve as an invaluable analog for interpreting the genesis of ancient sedimentary mound deposits.

  4. Buried cold-water coral mounds and contourite deposits in the Atlantic Moroccan Coral Province

    NASA Astrophysics Data System (ADS)

    Vandorpe, Thomas; Hebbeln, Dierk; Wienberg, Claudia; Van den Berghe, Michèle; Van Rooij, David

    2016-04-01

    The Atlantic Moroccan Coral Province (AMCP) is situated in the southern Gulf of Cadiz roughly between 34° 50'N to 35°35'N and 6°30'W to 7°15'W. The region displays tectonic (ridges and both large transverse as well as small normal and reverse faults) as well as sedimentological features (drifts deposits and sediment waves). Eleven mud volcanoes are present in the northern part of the region as well (Vandorpe et al., in press). Besides the presence of many surfacing small cold-water coral mounds, hundreds to thousands of mounds were discovered in the subsurface through 2D seismic parasound and sparker seismic profiles. Over 90% of the mounds are situated at water depths between 600 and 1000 meters and most of them occur in clusters. The cold-water coral mounds are rather small in this region (compared to the 100 m high mounds in the Belgica Province in the Porcupine basin (Huvenne et al., 2003)). Their widths vary between 20 and 200 m with a modus around 60 m, while their heights vary between 2 and 40 m with a modus around 10 m. Moreover, ten horizons at which mound growth initiated can be distinguished, compared to the single mound growth event observed in the Porcupine Basin (Huvenne et al., 2003). This points towards rapidly changing environmental conditions in the AMCP which were sometimes favourable for initiation and growth of cold-water coral mounds. These favourable periods rapidly switched to periods when corals were not able to settle and the mounds could get buried. Mound growth initiates mostly at elevated places, e.g. tectonic ridges, outcropping bedrock or even previous cold-water coral mounds. Elevated places deflect bottom currents and increase the amount of food particles and sediments delivered to the corals, but also create sedimentological features such as contourites. The contourite deposits in the region greatly depend on the slope of the topography against which they are present (Vandorpe et al., in press). When mounds were able to reach a

  5. Hyperspectral Remote Sensing of Seasonally-Acquired Imported Fire Ant Mound Features (Hymenoptera: Formicidae) in Turfgrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive mound-building imported fire ants (Solenopsis spp.) impact soil quality and turfgrass nutrient management in sod production, recreational, residential, and commercial settings. Ground-based hyperspectral studies focused on the seasonal monitoring of reflectance characteristics of imported f...

  6. Buried Cold-Water Coral Mound Provinces and Contourite Drifts Along the Eastern Atlantic Margin: Controls, Interactions and Connectivity

    NASA Astrophysics Data System (ADS)

    Van Rooij, D.; Vandorpe, T.; Delivet, S.; Hebbeln, D.; Wienberg, C.; Martins, I.

    2014-12-01

    The association between cold-water coral mounds and contourite drift deposits has been demonstrated in the Belgica mound province, off Ireland. On that location, IODP expedition 307 was able to drill through the base of a mound, dating mound initiation at 2.65 Ma. However, the Belgica mounds are just one of the many expressions of mound growth. More enigmatic is the buried Magellan mound province, located in the northern part of the Porcupine Basin, featuring over 1000 relatively closely spaced buried mounds, which are all rooted on a common reflector. This indicates a common start-up event, but the true driving forces behind their initial settling, growth and demise are still unknown. The influence of bottom currents cannot be ruled out, since clear obstacle marks are present surrounding the mounds. In 2013, some 3000 km south of the Magellan mounds, a new province of buried mounds was discovered along the Moroccan Atlantic Margin, which may shed new light on the "life" cycle of mounds. Here, we report the preliminary results and propose a first view on the controls, interactions and connectivity between these 2 provinces, assisted by a series of studies of contourite drifts along the Eastern Atlantic Margin. The newly discovered buried mounds can be associated to a vast province of several clusters of seabed mounds. They occur in water depths between 500 and 1000 m, buried under up to 50 m of sediment. With respect to the Magellan mounds, they are smaller, but more importantly, they do not root on one single stratigraphic level. At least 4 different initiation levels were identified. The off-mound reflectors indicate a slight influence of bottom currents, since the mounds are located in a large sediment drift. Moreover, the link between the two buried mound provinces may be found in connecting the evolution of the associated contourite drift systems, respectively in Porcupine Seabight and the Gulf of Cádiz. Intermediate sites on Goban Spur and near Le Danois

  7. Archaeological mounds as analogs of engineered covers for waste disposal sites: Literature review and progress report. [Appendix contains bibliography and data on archaeological mounds

    SciTech Connect

    Chatters, J C; Gard, H A

    1991-09-01

    Closure caps for low-level radioactive waste disposal facilities are typically designed as layered earthen structures, the composition of which is intended to prevent the infiltration of water and the intrusion of the public into waste forms. Federal regulations require that closure caps perform these functions well enough that minimum exposure guidelines will be met for at least 500 years. Short-term experimentation cannot mimic the conditions that will affect closure caps on the scale of centuries, and therefore cannot provide data on the performance of cap designs over long periods of time. Archaeological mounds hundreds to thousands of years old which are closely analogous to closure caps in form, construction details, and intent can be studied to obtain the necessary understanding of design performance. Pacific Northwest Laboratory conducted a review and analysis of archaeological literature on ancient human-made mounds to determine the quality and potential applicability of this information base to assessments of waste facility design performance. A bibliography of over 200 English-language references was assembled on mound structures from the Americas, Europe, and Asia. A sample of these texts was read for data on variables including environmental and geographic setting, condition, design features, construction. Detailed information was obtained on all variables except those relating to physical and hydrological characteristics of the mound matrix, which few texts presented. It is concluded that an extensive amount of literature and data are available on structures closely analogous to closure caps and that this information is a valuable source of data on the long-term performance of mounded structures. Additional study is recommended, including an expanded analysis of design features reported in the literature and field studies of the physical and hydraulic characteristics of different mound designs. 23 refs., 10 figs., 12 tabs.

  8. Isotope Biogeochemistry of Sulfur in a Cold-Water Carbonate Mound (IODP Site 1317)

    NASA Astrophysics Data System (ADS)

    Ferdelman, T. G.; Boettcher, M. E.

    2007-12-01

    To establish a depositional model for cold-water carbonate mounds, Challenger Mound and adjacent continental slope sites were drilled during IODP Expedition 307 in May 2005. Although a role for methane seepage and subsequent anaerobic oxidation was discounted both as a hard-round substrate for mound initiation and as a principal source of carbonate within the mound succession, interstitial water profiles of sulfate, alkalinity, Mg, and Sr indicated a tight coupling between carbonate diagenesis and mircrobial sulfate reduction. The reaction of sulfide with siliciclastic iron-bearing minerals to form pyrite was proposed to account for enhanced diagenetic carbonate precipitation (Ferdelman et al., 2006; Proc. IODP, vol. 307; doi:10.2204/iodp.proc.307.2006). To characterize these geomicrobial sulfur transformations in the carbonate mound sediments, the inorganic and stable isotope geochemical compositions of pore water sulfate and solid phase reduced sulfur compounds were performed. Acid-volatile sulfur (AVS) and pyrite del 34S compositions were usually similar and exhibited an increasing trend of from -40 per mil near surface to -20 per mil at the mound base at 132 mbsf. However, several excursions to more 34S sulfur enriched pyrite to values >0 per mil were observed in the deeper sections of the mound sequence. These excursions may be linked transitory changes in the depth of the methane-sulfate transition zone during mound build-up. The oxygen isotopic composition of residual dissolved sulfate indicates intracellular isotope exchange processes within the cells of SRBs, leading to increasing equilibration between extracellular pore water and sulfate.

  9. A Look Inside Rotating Rubble-Pile Asteroids Spun to Disruption

    NASA Astrophysics Data System (ADS)

    Sanchez Lana, Diego; Scheeres, Daniel J.

    2014-11-01

    Driven by the images obtained by different space missions to small asteroids, during the last few years different researchers have used self-gravitating granular mechanics codes for the simulation of small rubble-pile asteroids. One of the many topics of research has been the response of these bodies to rotational evolution due to YORP, specifically the deformation and ultimate disruption of small bodies due to elevated angular velocities.In this research we use self-gravitating aggregates formed by thousands of spheres and a soft-sphere granular dynamics code to explore the effect of the variation of two parameters, friction angle and tensile strength, on their disruption process. The aggregates were slowly spun up to disruption controlling for friction angle, cohesion and global shape. How much each aggregate deformed before disruption was directly related to the angle of friction. The greater it was, the less the aggregate deformed before disruption. Cohesive forces controlled the mode of disruption and maximum spin rate, showing that the aggregates could disrupt by shedding particles or groups of particles from the equatorial region. For high values of tensile strength, the pieces that detached from the initial aggregate were sizable enough for the disruption process to be seen as a fission. This implies that the change from shedding to fission is continuous and therefore, they should not be seen as different processes but just as two ends of the spectrum.A closer look at the spherical aggregates showed that the reshaping of the bodies was not symmetrical. A granular aggregate cannot be completely homogeneous unless its particles are arranged in a crystalline structure, something we avoided. This resulted in an asymmetrically reshaped body, similar to that of 1999 KW4 (at times forming a binary system). For ellipsoidal aggregates, this meant the formation of tear-drop shapes and pairs. The failing of the granular structure is ultimately controlled by the inter

  10. Anaerobic oxidation of methane in a cold-water coral carbonate mound from the Gulf of Cadiz

    NASA Astrophysics Data System (ADS)

    Maignien, L.; Depreiter, D.; Foubert, A.; Reveillaud, J.; de Mol, L.; Boeckx, P.; Blamart, D.; Henriet, J.-P.; Boon, N.

    2010-03-01

    The Gulf of Cadiz is an area of mud volcanism and gas venting through the seafloor. In addition, several cold-water coral carbonate mounds have been discovered at the Pen Duick escarpment amidst the El Arraiche mud volcano field on the Moroccan margin. One of these mounds -named Alpha mound- has been studied to examine the impact of the presence of methane on pore-water geochemistry, potential sulphate reduction (SR) rate and dissolved inorganic carbon (DIC) budget of the mound in comparison with off-mound and off-escarpment locations. Pore-water profiles of sulphate, sulphide, methane, and DIC from the on-mound location showed the presence of a sulphate to methane transition zone at 350 cm below the sea floor. This was well correlated with an increase in SR activity. 13C-depleted DIC at the transition zone (-21.9‰ vs. Vienna Pee Dee Belemnite) indicated that microbial methane oxidation significantly contribute to the DIC budget of the mound. The Alpha mound thus represents a new carbonate mound type where the presence and anaerobic oxidation of methane has an important imprint on both geochemistry and DIC isotopic signature and budget of this carbonate mound.

  11. The Surales, Self-Organized Earth-Mound Landscapes Made by Earthworms in a Seasonal Tropical Wetland.

    PubMed

    Zangerlé, Anne; Renard, Delphine; Iriarte, José; Suarez Jimenez, Luz Elena; Adame Montoya, Kisay Lorena; Juilleret, Jérôme; McKey, Doyle

    2016-01-01

    The formation, functioning and emergent properties of patterned landscapes have recently drawn increased attention, notably in semi-arid ecosystems. We describe and analyze a set of similarly spectacular landforms in seasonal tropical wetlands. Surales landscapes, comprised of densely packed, regularly spaced mounds, cover large areas of the Orinoco Llanos. Although descriptions of surales date back to the 1940's, their ecology is virtually unknown. From data on soil physical and chemical properties, soil macrofauna, vegetation and aerial imagery, we provide evidence of the spatial extent of surales and how they form and develop. Mounds are largely comprised of earthworm casts. Recognizable, recently produced casts account for up to one-half of total soil mass. Locally, mounds are relatively constant in size, but vary greatly across sites in diameter (0.5-5 m) and height (from 0.3 m to over 2 m). This variation appears to reflect a chronosequence of surales formation and growth. Mound shape (round to labyrinth) varies across elevational gradients. Mounds are initiated when large earthworms feed in shallowly flooded soils, depositing casts that form 'towers' above water level. Using permanent galleries, each earthworm returns repeatedly to the same spot to deposit casts and to respire. Over time, the tower becomes a mound. Because each earthworm has a restricted foraging radius, there is net movement of soil to the mound from the surrounding area. As the mound grows, its basin thus becomes deeper, making initiation of a new mound nearby more difficult. When mounds already initiated are situated close together, the basin between them is filled and mounds coalesce to form larger composite mounds. Over time, this process produces mounds up to 5 m in diameter and 2 m tall. Our results suggest that one earthworm species drives self-organizing processes that produce keystone structures determining ecosystem functioning and development. PMID:27168157

  12. The Surales, Self-Organized Earth-Mound Landscapes Made by Earthworms in a Seasonal Tropical Wetland

    PubMed Central

    Iriarte, José; Suarez Jimenez, Luz Elena; Adame Montoya, Kisay Lorena; Juilleret, Jérôme; McKey, Doyle

    2016-01-01

    The formation, functioning and emergent properties of patterned landscapes have recently drawn increased attention, notably in semi-arid ecosystems. We describe and analyze a set of similarly spectacular landforms in seasonal tropical wetlands. Surales landscapes, comprised of densely packed, regularly spaced mounds, cover large areas of the Orinoco Llanos. Although descriptions of surales date back to the 1940’s, their ecology is virtually unknown. From data on soil physical and chemical properties, soil macrofauna, vegetation and aerial imagery, we provide evidence of the spatial extent of surales and how they form and develop. Mounds are largely comprised of earthworm casts. Recognizable, recently produced casts account for up to one-half of total soil mass. Locally, mounds are relatively constant in size, but vary greatly across sites in diameter (0.5–5 m) and height (from 0.3 m to over 2 m). This variation appears to reflect a chronosequence of surales formation and growth. Mound shape (round to labyrinth) varies across elevational gradients. Mounds are initiated when large earthworms feed in shallowly flooded soils, depositing casts that form ‘towers’ above water level. Using permanent galleries, each earthworm returns repeatedly to the same spot to deposit casts and to respire. Over time, the tower becomes a mound. Because each earthworm has a restricted foraging radius, there is net movement of soil to the mound from the surrounding area. As the mound grows, its basin thus becomes deeper, making initiation of a new mound nearby more difficult. When mounds already initiated are situated close together, the basin between them is filled and mounds coalesce to form larger composite mounds. Over time, this process produces mounds up to 5 m in diameter and 2 m tall. Our results suggest that one earthworm species drives self-organizing processes that produce keystone structures determining ecosystem functioning and development. PMID:27168157

  13. Sedimentology of a Mid-Late Ordovician carbonate mud-mound complex from the Kathmandu nappe in Central Nepal

    NASA Astrophysics Data System (ADS)

    Pas, Damien; Da Silva, Anne-Christine; Dhital, Megh Raj; Boulvain, Frédéric

    2011-08-01

    This sedimentological study of the Godavari quarry is the first relating to the Palaeozoic Tethyan sedimentary rocks of the Katmandu nappe (Central Nepal). Sedimentological analyses led to the identification of six microfacies belonging to a large carbonate mud-mound complex, which can be divided into mound, flank and off-mound main depositional settings. Identification of two dasycladaceans ( Dasyporell a cf. silurica ( Stolley, 1893) and Vermiporella sp.) in the mound facies gives a Mid-Late Ordovician age to this newly discovered Godavari carbonate mud-mound, which makes this mound one of the oldest ever described in the Asian continent. The mound microfacies are characterized by a high micritic content, the presence of stromatactis and the prevalence of red coloured sediments (the red pigmentation probably being related to organic precipitation of iron). The flank microfacies are characterized by a higher crinoid and argillaceous content and the presence of bio- and lithoclasts concentrated in argillaceous lenses. Finally, the off-mound microfacies show very few bioclasts and a high argillaceous content. Palaeoenvionmental interpretation of microfacies, in terms of bathymetry, leads us to infer that the Godavari mud-mound started to grow in a deep environment setting below the photic and wave action zones and that it evolved to occupy a location below the fair weather wave base. Cementation of cavities within the mound facies underlines a typical transition from a marine to a burial diagenetic environment characterized by: (1) a radiaxial non luminescent feroan calcite cement (marine) showing a bright orange luminescent band in its middle part; (2) a bright zoned orange fringe of automorphic feroan calcite (meteoric phreatic); (3) a dull orange xenomorphic feroan calcite cement in the centre of cavities (burial) and (4) a saddle dolomite within the centre of larger cavities. The faunal assemblage (diversity and relative proportion) of the Godavari mound facies

  14. Regional Mapping and Spectral Analysis of Mounds in Acidalia Planitia, Mars

    NASA Technical Reports Server (NTRS)

    Amador, E. S.; Allen, Carlton; Oehler, D. Z.

    2010-01-01

    Acidalia Planitia is a approx.3000 km diameter planum located in the northern plains of Mars. It is believed to be a sedimentary basin containing an accumulation of sediments brought by Hesperian outflow channels that drained the Highlands. A large number of high-albedo mounds have been identified across this basin [1-2] and understanding the process that formed them should help us understand the history of this region. Farrand et al. [2] showed that the mounds are dark in THEMIS (Thermal Emission Imaging System) nighttime IR (infrared) image data. This implies that the mounds have a lower thermal inertia than the surrounding plains (Fig. 1), suggesting that the material of the mounds is fine-grained or unconsolidated. Farrand et al. [2] also reviewed potential analogs for the mounds and concluded that a combination of mud volcanoes with evaporites around geysers or springs is most consistent with all the data. We have built on this work by creating regional maps of the features and analyzing CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) data to see if there are mineralogical differences between the mounds and surrounding plains.

  15. Oil reservoirs in grainstone aprons around Bryozoan Mounds, Upper Harrodsburg Limestone, Mississippian, Illinois Basin

    SciTech Connect

    Jobe, H.; Saller, A.

    1995-06-01

    Several oil pools have been discovered recently in the upper Harrodsburg Limestone (middle Mississippian) of the Illinois basin. A depositional model for bryozoan mound complexes has allowed more successful exploration and development in this play. In the Johnsonville area of Wayne County, Illinois, three lithofacies are dominant in the upper Harrodsburg: (1) bryozoan boundstones, (2) bryozoan grainstones, and (3) fossiliferous wackestones. Bryozoan boundstones occur as discontinuous mounds and have low porosity. Although bryozoan boundstones are not the main reservoir lithofacies, they are important because they influenced the distribution of bryozoan grainstones and existing structure. Bryozoan grainstones have intergranular porosity and are the main reservoir rock. Bryozoan fragments derived from bryozoan boundstone mounds were concentrated in grainstones around the mounds. Fossiliferous wackestones are not porous and form vertical and lateral seals for upper Harrodsburg grainstones. Fossiliferous wackestones were deposited in deeper water adjacent to bryozoan grainstone aprons, and above grainstones and boundstones after the mounds were drowned. Upper Harrodsburg oil reservoirs occur where grainstone aprons are structurally high. The Harrodsburg is a good example of a carbonate mound system where boundstone cores are not porous, but adjacent grainstones are porous. Primary recovery in these upper Harrodsburg reservoirs is improved by strong pressure support from an aquifer in the lower Harrodsburg. Unfortunately, oil production is commonly decreased by water encroaching from that underlying aquifer.

  16. Zonation of Microbial Communities by a Hydrothermal Mound in the Atlantis II Deep (the Red Sea).

    PubMed

    Wang, Yong; Li, Jiang Tao; He, Li Sheng; Yang, Bo; Gao, Zhao Ming; Cao, Hui Luo; Batang, Zenon; Al-Suwailem, Abdulaziz; Qian, Pei-Yuan

    2015-01-01

    In deep-sea geothermal rift zones, the dispersal of hydrothermal fluids of moderately-high temperatures typically forms subseafloor mounds. Major mineral components of the crust covering the mound are barite and metal sulfides. As a result of the continental rifting along the Red Sea, metalliferous sediments accumulate on the seafloor of the Atlantis II Deep. In the present study, a barite crust was identified in a sediment core from the Atlantis II Deep, indicating the formation of a hydrothermal mound at the sampling site. Here, we examined how such a dense barite crust could affect the local environment and the distribution of microbial inhabitants. Our results demonstrate distinctive features of mineral components and microbial communities in the sediment layers separated by the barite crust. Within the mound, archaea accounted for 65% of the community. In contrast, the sediments above the barite boundary were overwhelmed by bacteria. The composition of microbial communities under the mound was similar to that in the sediments of the nearby Discovery Deep and marine cold seeps. This work reveals the zonation of microbial communities after the formation of the hydrothermal mound in the subsurface sediments of the rift basin. PMID:26485717

  17. Zonation of Microbial Communities by a Hydrothermal Mound in the Atlantis II Deep (the Red Sea)

    PubMed Central

    Wang, Yong; Li, Jiang Tao; He, Li Sheng; Yang, Bo; Gao, Zhao Ming; Cao, Hui Luo; Batang, Zenon; Al-Suwailem, Abdulaziz; Qian, Pei-Yuan

    2015-01-01

    In deep-sea geothermal rift zones, the dispersal of hydrothermal fluids of moderately-high temperatures typically forms subseafloor mounds. Major mineral components of the crust covering the mound are barite and metal sulfides. As a result of the continental rifting along the Red Sea, metalliferous sediments accumulate on the seafloor of the Atlantis II Deep. In the present study, a barite crust was identified in a sediment core from the Atlantis II Deep, indicating the formation of a hydrothermal mound at the sampling site. Here, we examined how such a dense barite crust could affect the local environment and the distribution of microbial inhabitants. Our results demonstrate distinctive features of mineral components and microbial communities in the sediment layers separated by the barite crust. Within the mound, archaea accounted for 65% of the community. In contrast, the sediments above the barite boundary were overwhelmed by bacteria. The composition of microbial communities under the mound was similar to that in the sediments of the nearby Discovery Deep and marine cold seeps. This work reveals the zonation of microbial communities after the formation of the hydrothermal mound in the subsurface sediments of the rift basin. PMID:26485717

  18. Constraints on Subsurface gas and gas Hydrate Distribution in a Gulf of Mexico Mound

    NASA Astrophysics Data System (ADS)

    Wood, W. T.; Hutchinson, D.; Hart, P.; Snyder, F.; Voss, C.; Dutta, N.; Muller, L.; Lee, M.; Gardner, J.; Dugan, B.; Ruppel, C.; Coffin, R.; Evans, R.; Jones, E.

    2003-12-01

    The Gulf of Mexico is well known for seafloor methane hydrate accumulations associated with hydrocarbon seeps, but the distribution of free gas, gas in solution and gas hydrate below the mounds is poorly known. Numerical simulation of fluid flow and analyses of industry 3-D seismic data (reprocessed for higher resolution in the shallow sediments), and high resolution seismic data recently acquired by the USGS provide some constraints on the distribution of these phases via their significantly different effect on seismic returns. Below an 8 m high, 300 m diameter mound at 1300 m water depth in Atwater Valley lease block 14, lies a convex upward, bell-shaped, subsurface reflection. The reflection can be modeled quite closely as a reflection from the base of hydrate stability (top of gas here) perturbed from about 300 to 45 m below the seafloor by localized, upward fluid and heat flux. The flow modeling therefore predicts free gas much higher below the mound than away from the mound. This is confirmed in the USGS data by a push down of 24 percent on a reflection passing below the perturbation, suggesting a velocity below the mound of less than 1400 m/s, indicative of at least some free gas. A strong upward perturbation to the base of the hydrate stability zone significantly constrains the volume available for methane hydrate formation below the seafloor, potentially impacting volume estimates of methane hydrate below seafloor mounds.

  19. Textural variation within Great Salt Lake algal mounds: Chapter 8.5 in Stromatolites

    USGS Publications Warehouse

    1976-01-01

    This chapter discusses textural variation within the Great Salt Lake algal mounds. Great Salt Lake algal mounds contain: (1) a framework of non-skeletal, algally induced aragonite precipitates; (2) internal sediment; and (3) inorganic cement. These three elements create a variety of laminated, poorly laminated, and unlaminated internal textures. Interior framework precipitates bear little resemblance to the present living film of the mound surface. Internal texture of the mounds is believed to be largely relict and to have resulted from precipitation by algae different than those presently living at the surface. The most probable cause of local extinction of the algal flora is change in brine salinity. Precipitated blue-green algal structures in ancient rocks may indicate other than normal marine salinity and near shore sedimentation. Extreme variation of internal texture reflects extreme environmental variability typical of closed basin lakes. Recognition of mounds similar to those in the Great Salt Lake can be a first step toward recognition of ancient hyper-saline lake deposits, if such an interpretation is substantiated by consideration of the entire depositional milieu of precipitated algal mounds.

  20. Benthic dynamics at the carbonate mound regions of the Porcupine Sea Bight continental margin

    NASA Astrophysics Data System (ADS)

    White, Martin

    2007-02-01

    A brief review is given of some dynamical processes that influence the benthic dynamics within the carbonate mound provinces located at the Porcupine Bank/Sea Bight margin, NE Atlantic. The depth range of the mounds in this region (600-1,000 m) marks the upper boundary of the Mediterranean outflow water above which Eastern North Atlantic Water dominates. Both water masses are carried northwards by the eastern boundary slope current. In the benthic boundary layer both the action of internal waves, and other tidal period baroclinic waves, may enhance the bottom currents and add to both the residual and maximum flow strength. Both residual and maximum bottom currents vary at different mound locations, with stronger currents found at Belgica (SE Porcupine Sea Bight) mound and Pelagia (NW Porcupine Bank) mound regions, whilst weakest currents are found at the Hovland and Magellan Mounds at the northern Sea Bight margin. The differences may be attributed to the presence of internal waves (Pelagia) or bottom intensified diurnal waves (Belgica). These different dynamical regimes are likely to have implications for the distribution patterns of live coral at the different locations.

  1. U-Th age distribution of coral fragments from multiple rubble ridges within the Frankland Islands, Great Barrier Reef: Implications for past storminess history

    NASA Astrophysics Data System (ADS)

    Liu, Entao; Zhao, Jian-xin; Feng, Yue-xing; Leonard, Nicole D.; Clark, Tara R.; Roff, George

    2016-07-01

    Prograded coral rubble ridges have been widely used as archives for reconstructing long-term storm or storminess history. Chronologies of ridge systems in previous studies are often based on a limited number of low-resolution radiocarbon or optically-stimulated luminescence (OSL) ages per ridge (usually only one age per ridge), which carry intrinsic age uncertainties and make interpretation of storm histories problematic. To test the fidelity of storm ridges as palaeo-storm archives, we used high-precision U-Th dating to examine whether different samples from a single ridge are temporally constrained. We surveyed three transects of ridge systems from two continental islands (Normanby Island and High Island) within the Frankland Islands, Great Barrier Reef (GBR), and obtained 96 U-Th dates from coral rubble samples collected from within and between different ridges. Our results revealed significant differences in age ranges between the two islands. The steeper and more defined rubble ridges present on Normanby Island revealed that the majority of U-Th ages (over 60%) from a single ridge clustered within a narrow age range (∼100 years). By contrast, the lower and less defined ridges on High Island, which were more likely formed during both storm and non-storm high-energy events, revealed significant scatter in age distribution (>>200 years) with no notable clustering. The narrower age ranges obtained from the steeper and more defined rubble ridges suggest that previous approaches of using either limited samples from a single ridge or low-precision dating methods to establish chronologies are generally valid at centennial to millennial timescales, although caution must be taken to use such approaches for storm history reconstruction on shorter timescales (e.g. decadal). The correlation between U-Th mortality ages of coral rubble and historical stormy periods highlights the possibility of using coral rubble age distribution from rubble ridges to reconstruct the long

  2. Biogeochemistry and geomicrobiology of cold-water coral carbonate mounds - lessons learned from IODP Expedition 307

    NASA Astrophysics Data System (ADS)

    Ferdelman, Timothy; Wehrmann, Laura; Mangelsdorf, Kai; Kano, Akihiro; Williams, Trevor; Jean-Pierre, Henriet

    2010-05-01

    Large mound structures associated with cold-water coral ecosystems commonly occur on the slopes of continental margins, for instance, west of Ireland in the Porcupine Seabight, the Gulf of Cadiz or the Straits of Florida. In the Porcupine Seabight over 1500 mounds of up to 5 km in diameter and 250 m height lie at water depths of 600 to 900 m. The cold-water coral reef ecosystems associated with these structures are considered to be "hotspots" of organic carbon mineralization and microbial systems. To establish a depositional and biogeochemical/diagenetic model for cold-water carbonate mounds, Challenger Mound and adjacent continental slope sites were drilled in May 2005 during IODP Expedition 307. One major objective was to test whether deep sub-surface hydrocarbon flow and enhanced microbial activity within the mound structure was important in producing and stabilizing these sedimentary structures. Drilling results showed that the Challenger mound succession (IODP Site U1317) is 130 to 150 meters thick, and mainly consists of floatstone and rudstone facies formed of fine sediments and cold-water branching corals. Pronounced recurring cycles on the scales of several meters are recognized in carbonate content (up to 70% carbonate) and color reflectance, and are probably associated with Pleistocene glacial-interglacial cycles. A role for methane seepage and subsequent anaerobic oxidation was discounted both as a hard-round substrate for mound initiation and as a principal source of carbonate within the mound succession. A broad sulfate-methane transition (approximately 50 m thick)within the Miocene sediments suggested that the zone of anaerobic oxidation of methane principally occurs below the moundbase. In the mound sediments, interstitial water profiles of sulfate, alkalinity, Mg, and Sr suggested a tight coupling between carbonate diagenesis and low rates of microbial sulfate reduction. Overall organic carbon mineralization within cold-water coral mound appeared

  3. Bryan Mound SPR cavern 113 remedial leach stage 1 analysis.

    SciTech Connect

    Rudeen, David Keith; Weber, Paula D.; Lord, David L.

    2013-08-01

    The U.S. Strategic Petroleum Reserve implemented the first stage of a leach plan in 2011-2012 to expand storage volume in the existing Bryan Mound 113 cavern from a starting volume of 7.4 million barrels (MMB) to its design volume of 11.2 MMB. The first stage was terminated several months earlier than expected in August, 2012, as the upper section of the leach zone expanded outward more quickly than design. The oil-brine interface was then re-positioned with the intent to resume leaching in the second stage configuration. This report evaluates the as-built configuration of the cavern at the end of the first stage, and recommends changes to the second stage plan in order to accommodate for the variance between the first stage plan and the as-built cavern. SANSMIC leach code simulations are presented and compared with sonar surveys in order to aid in the analysis and offer projections of likely outcomes from the revised plan for the second stage leach.

  4. Cost estimate for muddy water palladium production facility at Mound

    SciTech Connect

    McAdams, R.K.

    1988-11-30

    An economic feasibility study was performed on the ''Muddy Water'' low-chlorine content palladium powder production process developed by Mound. The total capital investment and total operating costs (dollars per gram) were determined for production batch sizes of 1--10 kg in 1-kg increments. The report includes a brief description of the Muddy Water process, the process flow diagram, and material balances for the various production batch sizes. Two types of facilities were evaluated--one for production of new, ''virgin'' palladium powder, and one for recycling existing material. The total capital investment for virgin facilities ranged from $600,000 --$1.3 million for production batch sizes of 1--10 kg, respectively. The range for recycle facilities was $1--$2.3 million. The total operating cost for 100% acceptable powder production in the virgin facilities ranged from $23 per gram for a 1-kg production batch size to $8 per gram for a 10-kg batch size. Similarly for recycle facilities, the total operating cost ranged from $34 per gram to $5 per gram. The total operating cost versus product acceptability (ranging from 50%--100% acceptability) was also evaluated for both virgin and recycle facilities. Because production sizes studied vary widely and because scale-up factors are unknown for batch sizes greater than 1 kg, all costs are ''order-of-magnitude'' estimates. All costs reported are in 1987 dollars.

  5. Earth-mounded concrete bunker PLAP technical approach

    SciTech Connect

    Eng, R.

    1989-11-01

    Under the US DOE Prototype License Application Project (PLAP), Ebasco Services Incorporated was commissioned to develop a preliminary design of the Earth-Mounded Concrete Bunker (EMCB) concept for low-level radioactive waste (LLW) disposal. The EMCB disposal concept is of great interest because it represents the only engineered LLW disposal technology currently in use in the commercial sector. By definition, the EMCB disposal structure is located partially below grade and partially above grade. The concrete bunker is an engineered structure designed to be structurally stable for the prerequisite time horizon. The basic design parameters of the disposal facility were stipulated by US DOE, a northeast site location, representative waste, 30 year operational life, and a 250,000 ft{sup 3}/year disposal capacity. The design was developed to satisfy only US NRC Part 61 disposal requirements, not individual state requirements that may go beyond Part 61 requirements. The technical safety analysis of the preliminary design was documented according to the format specifications of NUREG-1199, to the extent practicable with quite limited resources.

  6. Origin Hypotheses for Kilometer-Scale Mounds on Dwarf Planet Ceres

    NASA Astrophysics Data System (ADS)

    Sizemore, Hanna G.; Platz, Thomas; Schmidt, Britney E.; Scully, Jennifer E. C.; Russell, Christopher T.; Mest, Scott C.; Crown, David A.; Sykes, Mark V.; Hughson, Kynan H. G.; Chilton, Heather T.; Williams, David A.; Pieters, Carle M.; Marchi, Simone; Travis, Bryan; Raymond, Carol A.

    2015-11-01

    The Dawn Framing Camera has revealed numerous domical to conical features on Ceres, which may have relevance to the presence and history of near-surface ice. These features fall into two broad classes, large domes 10s to >100 km in diameter exhibiting 1-5 km of positive relief, and small mounds <10 km in diameter exhibiting sub-kilometer relief. Here, we propose three hypotheses for the origin of the ~150 small mounds identified thus far, and discuss morphological observations that could support each hypothesis as higher resolution data becomes available.Hypothesis 1: Kilometer-scale mounds are produced by localized eruption of cryomagma or hydrothermal material. Observational tests: Kilometer and sub-kilometer scale albedo variations; sub-kilometer flow features on individual mounds; localized vents; conical or domical shape. Challenge: Features are smaller than convective plumes expected from thermal evolution modeling.Hypothesis 2: Kilometer-scale mounds are analogous to terrestrial and martian pingos, which grow by drawing liquid water through a silicate matrix as a freezing front propagates downward. Observational tests: Mounds occurring on smooth material that floods or embays large-scale features; little or no local albedo variation; no small flows associated with individual mounds; domical or ring-shape; concentric or radial fractures on dome, or central depression. Challenge: Small Cerean mounds observed thus far are an order of magnitude larger than terrestrial or martian pingos.Hypothesis 3: Kilometer-scale mounds are rootless cones analogous to features observed on the surface of volcanic flows in volatile-rich regions of Earth and Mars. Rootless cones are produced when layers of fluid material inundate a region; localized devolatilization of a layer mobilizes clasts to form cone-shaped deposits. Observational tests: Mounds on smooth material that floods or embays large-scale features; conical, not domical, profile; large central

  7. AUV Reveals Deep-Water Coral Mound Distribution, Morphology and Oceanography in the Florida Straits

    NASA Astrophysics Data System (ADS)

    Grasmueck, M.; Eberli, G. P.; Viggiano, D. A.; Correa, T.; Rathwell, G.; Luo, J.

    2006-12-01

    Since the 1960's dredge sampling and submersible dives have discovered numerous mound-forming deep- water corals in water depths of 400-800 m in the Straits of Florida. This extensive collection of samples and observations however can not be put into a geomorphologic context as existing bathymetric charts do not resolve coral mounds. To make progress in understanding the distribution and genesis of coral mounds, maps of morphology and oceanographic conditions resolving features at the 1-10 m scale are needed. On 11-18 December 2005 the C-Surveyor II(TM) mapped five sites ranging from 14-48 km2 in 590-875 m water acquiring 1-3 m resolution bathymetry and acoustic backscatter together with subbottom profiles, current vectors, salinity, and temperature. The areas mapped with the AUV contain hundreds of coral mounds with heights of 1-120 m. Mound distribution, morphology and currents are different for each survey site. Coral mounds develop on off-bank transported sediment ridges and slump features at the toe-of-slope of Great Bahama bank, while chevron pattern ridges and sinusoidal ridges are found further east in the Straits. Currents range from 0.1-0.5 m/s. At two sites currents reversed every 6 hours indicating tidal control. The AUV surveys and subsequent ground truthing with a drop camera and a submersible revealed a surprising abundance and diversity of deep-water coral habitats. The boundaries between mound fields and the barren muddy or sandy seafloor are sharp. Hull- mounted multi-beam reconnaissance mapping helped us select the most promising coral mound areas to optimize the use of valuable AUV time. Such combined use of hull-mounted and AUV-based mapping enables efficient environmental characterization of large deep-water regions such as the Florida Straits. The synoptic high-resolution datasets acquired by the multiple sensors on board the AUV enable for the first time a comprehensive assessment of deep-water coral mound ecosystems. Utilization of such

  8. Science Targets in the Landing Ellipse and Lower Mound at the Gale Crater Field Site

    NASA Astrophysics Data System (ADS)

    Anderson, R. B.; Bell, J. F.

    2011-12-01

    The Mars Science Laboratory (MSL) rover Curiosity will land at the ~155 km diameter Gale Crater (4.6°S 137.2°E) in early August of 2012. The landing ellipse is centered in the northwestern floor of the crater on an alluvial fan composed of material from the crater rim. MSL will sample this material and test the hypothesis that the fan was deposited by flowing liquid water, and then drive south toward the base of the >5km tall central mound of layered rocks. Along this traverse, the smooth, low-thermal-inertia surface of the alluvial fan transitions to a fractured, layered, and spectrally neutral high thermal inertia unit. MSL will be able to assess the interpretation of this unit as cemented alluvial material and determine the cementing agent. Fresh craters in the high thermal inertia unit are important targets for MSL because their ejecta has had less exposure to the harsh radiation environment of the surface which can destroy biomarkers. Continuing south, MSL will descend across a short scarp where the units of the crater floor have eroded to expose the underlying basal unit of the mound. This erosion has formed ridged mesas interpreted to be lithified aeolian bedforms that are part of a widespread "mound-skirting" unit. MSL will test the hypothesis that this unit comprises debris shed from the mound during an early stage of erosion. The heavily fractured basal unit is partially obscured by relatively young mafic dunes, which will provide information about modern aeolian processes on Mars. After analyzing the basal unit and the dunes, MSL will begin climbing the layered rocks of the mound, beginning with a light-toned ridge which shows spectral evidence of hydrated sulfates. Beyond this ridge, the rover will encounter a phyllosilicate-bearing surface exposed in a trough paralleling the ridge. These lower mound layers are the primary targets of the MSL traverse. MSL will test the hypothesis that the lower mound sediments were deposited in a lacustrine setting

  9. Concentration of Actinides in Plant Mounds at Safety Test Nuclear Sites in Nevada

    SciTech Connect

    David S. Shafer; Jenna Gommes

    2008-09-15

    Plant mounds or blow-sand mounds are accumulations of soil particles and plant debris around large shrubs and are common features in deserts in the southwestern United States. Believed to be an important factor in their formation, the shrubs create surface roughness that causes wind-suspended particles to be deposited and resist further suspension. Shrub mounds occur in some plant communities on the Nevada Test Site, the Nevada Test and Training Range (NTTR), and Tonopah Test Range (TTR), including areas of surface soil contamination from past nuclear testing. In the 1970s as part of early studies to understand properties of actinides in the environment, the Nevada Applied Ecology Group (NAEG) examined the accumulation of isotopes of Pu, {sup 241}Am, and U in plant mounds at safety test sites. The NAEG studies found concentrations of these contaminants to be greater in shrub mounds than in the surrounding areas of desert pavement. For example, at Project 57 on the NTTR, it was estimated that 15 percent of the radionuclide inventory of the site was associated with shrub mounds, which accounted for 17 percent of the surface area of the site, a ratio of inventory to area of 0.85. At Clean Slate III at the TTR, 29 percent of the inventory was associated with approximately 32 percent of the site covered by shrub mounds, a ratio of 0.91. While the total inventory of radionuclides in intershrub areas was greater, the ratio of radionuclide inventory to area was 0.40 and 0.38, respectively, at the two sites. The comparison between the shrub mounds and adjacent desert pavement areas was made for only the top 5 cm since radionuclides at safety test sites are concentrated in the top 5 cm of intershrub areas. Not accounting for radionuclides associated with the shrub mounds would cause the inventory of contaminants and potential exposure to be underestimated. As part of its Environmental Restoration Soils Subproject, the U.S. Department of Energy (DOE), National Nuclear

  10. Carbonate mound reservoirs in the paradox formation: An outcrop analogue along the San Juan River, Southeastern Utah

    SciTech Connect

    Chidsey, T. C. Jr.; Morgan, C.D.; Eby, D.E.

    1996-06-01

    Carbonate mound reservoirs within the Pennsylvanian (Desmoinesian) Paradox Formation are major producers of oil and gas in the Paradox basin of Utah, Colorado, and Arizona. Outcrops of the Paradox Formation along the San Juan River of southeastern Utah provide small-scale analogues of reservoir heterogeneity, flow barriers and baffles, lithofacies, and geometry. These characteristics can be used in reservoir simulation models for secondary/tertiary recovery of oil from small fields in the basin. Exposures of the Paradox Formation Ismay zone in the Wild Horse Canyon area display lateral facies changes from phylloid algal mounds to off-mound detrital wedges or fans bounded at the top by a flooding surface. The phylloid mounds are composed of bafflestone, skeletal grainstone, packstone, and cementstone. Algal plates, brachiopods, bryozoans, and rugose corals are commonly found in the phylloid mounds. The mound wall is composed of rudstone, lumpstone, and cementstone. The detrital fan consists of transported algal material, grainstone, and mudstone with open-marine fossils. Within the mound complex is an inter-mound trough tentatively interpreted to be a tidal channel. The geometry and composition of the rocks in the trough significantly add to the overall heterogeneity of the mound. Reservoir models are being developed for possible water- and carbon-dioxide floods of small Paradox basin fields to determine the most effective secondary/tertiary recovery method. The models will include lithologic fabrics, flooding surfaces, and inter-mound troughs, based on the mound complex exposed at Wild Horse Canyon. This project may also provide reservoir information for simulation models in small Paleozoic carbonate mound fields in other basins worldwide.

  11. Spin-induced mass loss from rubble piles and the formation of asteroid satellites and pairs

    NASA Astrophysics Data System (ADS)

    Tanga, P.; Campo Bagatin, A.; Thirouin, A.; Cellino, A.; Comito, C.; Ortiz, J.; Richardson, D.; Hestroffer, D.

    2014-07-01

    Non-gravitational effects may change the angular momentum of asteroids up to a few tens of km in size to the point that rotational stability is lost at high spin rates. Once instability is initiated, mass loss may happen and potentially create satellites or dynamically detached components (pairs). We have studied this problem by means of numerical simulations and investigated the production of secondary objects of different sizes by direct splitting of the parent body under the assumption of a low internal angle of friction. We focused our attention on the effect of progressive spin-up of objects as a consequence of the YORP effect. Since asteroids are clearly not fluid but rocky bodies, one can assume that equilibrium theories --- also describing bifurcations (e.g., [1]) --- do not directly apply [2]. The equilibrium shapes of non-fluid bodies have been studied in the recent past by several authors, assuming that rubble-pile asteroids can be modeled as cohesionless granular systems in the frame of continuum theories [2--5]. [6] shows that a small amount of tensile strength could be sufficient for the survival of some fast rotators, even if they are internally fragmented. More relevant to this work are the results obtained by [7,8] by the same N-body approach that we use, i.e., by simulating the dynamics and the collisions of mono-dispersed hard spheres utilizing the PKDGRAV code [9,10]. The YORP effect is modeled by increasing rigid rotation by small increments with enough time to relax between subsequent spin-ups. In this work, our approach is based again on the same simulation code; however, our new exploration of the parameter space is broader than the previous study in the near-fluid regime, which is achieved by randomizing the initial particle positions somewhat to break the otherwise crystalline structure of monodisperse particle packing. We find that the transformation of objects into prolate ellipsoids is an efficient process when the internal angle of

  12. Microbial Biodiversity in the Subsurface of Carbonate Mounds from the Gulf of Cadiz off Morocco

    NASA Astrophysics Data System (ADS)

    Templer, S. P.; Stadnitskaia, A.; de Haas, H.; Bernasconi, S.; Vasconcelos, C.; McKenzie, J. A.

    2008-12-01

    The study area, El Arraiche mud volcano field, is situated 35 km offshore the north-western Moroccan margin, on top of the accretionary wedge of the Gulf of Cadiz. An exploratory cruise of R/V Belgica in 2002 off Larache (Morocco) has led to the discovery of small mounds topping ridges and structural heights, respectively on Pen Duick Escarpment, Renard Ridge, Vernadsky Ridge and Al Idrisi Ridge. These mounds are found amidst 9 giant mud volcanoes and occur in a setting where focused fluid seepage is observed. Subsequent cruises have confirmed the colonization by dominantly lifeless cold-water corals and have unveiled extensive fields of seep-related carbonates in off-reef regions. We present the microbial biodiversity of the subsurface of two different carbonate mounds (alpha- and beta-mound) flanked by a giant double- peaked mud volcano in the Pen Duick Mound Province in a water depths of 500-600 m. Most of the sediment comprises pelagic calcite (coccoliths), detrital quartz and authigenic dolomite, often observed encasing coccoliths. Stable carbon isotope values of the bulk carbonate range from -7 to -15 permil indicating the involvement of microbes in the production of bicarbonate ions. Pore water analysis evidences a sharp sulphate-methane-transition (SMT) zone at 3.5 m below the mound top, whereas the depth of no sulfate is much deeper in the surrounding sediments. The horizon characterized by a strong corrosion of the coral fragments is just lying above and at the front of the recent location of the zone of anaerobic methane oxidation (AOM). In order to define the primary microbial community involved in carbonate precipitation, we did direct culturing, DNA isolation and PCR analysis of functional genes, including archaeal and bacterial 16S rRNA gene analysis. In combination with a DGGE approach, we developed a microbial biodiversity profile along the two carbonate mounds.

  13. Office of Inspector General report on audit of shutdown and transition of the Mound Plant

    SciTech Connect

    1997-06-24

    With the end of the Cold War, the Department of Energy (Department) has greatly reduced the production of nuclear weapons and redirected the capabilities and focus of the weapons complex. As part of this redirection, the Mound Plant was transferred from a Defense Program site to an Environmental Management site with emphasis on accelerated cleanup and transition of facilities and personal property to the local community. This audit was initiated to determine if the shutdown and transition of the Mound Plant was progressing effectively and efficiently. The Department prepared a Nonnuclear Consolidation Plan (NCP) designed to reduce its costs of operation by closing and consolidating facilities. In contrast to the goal of the NCP, the Department plans to keep a portion of the Mound Plant open solely to perform work for other Federal agencies. Specifically, the Department has decided to continue assembling and testing isotopic heat sources and radioisotope thermoelectric generators (HS/RTG) at the Mound Plant despite the transfer or planned transfer of all other production operations.The Office of Nuclear Energy, Science and Technology decided to continue its HS/RTG operations at the Mound Plant without adequately considering the overall economic goals of the Department. As a result, the Department may not achieve the savings envisioned by the NCP. Also, the Department may incur between $4 million and $8.5 million more than necessary each year to continue its HS/RTG operations at the Mound Plant. Additionally, if the HS/RTG operations stay at the Mound Plant, the Department will spend more than $3 million to consolidate these operations into one location.

  14. Numerical simulation of ground water mounding and its verification by Hele Shaw model

    NASA Astrophysics Data System (ADS)

    Tsay, Tswn-Syau; Hoopes, John A.

    1998-12-01

    Ground water mounding is the rise of the water table above its regional level in a local area of an aquifer in order to provide sufficient head to distribute the water supplied by a localized source to that area. The shape and height of the mound depend on many factors including recharge rate and distribution, geology, hydraulic conductivity, flow/head control locations, saturated thickness and regional flow in the aquifer in that area. In this work, an accurate and efficient numerical model for calculating ground water mounding was developed. Numerical calculations were done on a uniform rectangular grid, obtained by a transformation of the physical domain. Grid for computation were generated by a grid generation code, EagleView, which is developed by the Mississippi State University. Model predictions were verified with tests in a Hele-Shaw model for situations with and without a regional flow, with and without heterogeneity, and for two recharge rates. SAE#50 oil was used as the fluid in the Hele-Shaw. A peristaltic pump was used to supply the constant (and adjustable) recharge rate from the reservoir below the Hele-Shaw model. The results of experiments of estimating mounds and the numerical mounding model are in good agreement. However, mound height of the region below recharge of Hele-Shaw model can not be observed because the flow of this region combines vertical flow from recharge and the rising of the free surface (horizontal flow). Hence, an emulated perched aquifer was used so that mound height of the recharge region can be observed.

  15. Permanent groundwater storage in basaltic dyke fractures and termite mound viability

    NASA Astrophysics Data System (ADS)

    Mège, Daniel; Rango, Tewodros

    2010-04-01

    Many basaltic dykes of the Ethiopian flood basalt province are observed in the northwestern Ethiopian lowlands. In this area, the termites preferentially build their epigeous mounds on the top of dolerite dykes. The relationship between termite mounds and dykes is investigated from the analysis of their distribution along one of these dykes, of thickness 2-5 m, that we could follow over 2000 m. Termite mounds are periodically spaced (mean distance 63 m, R2 = 0.995), and located exclusively where the topographic relief of the dyke is not more than 2 m above the surrounding area. From these observations and from the geological context, a hydrological circuit model is proposed in which (1) dykes are preferential conduits for groundwater drainage during the rainy season due to pervasive jointing, (2) during the dry season, the portion of the dyke forming a local topographic relief area dries up more quickly than the surroundings, the elevation difference between the dyke summit and the surroundings being a factor restricting termite mound development. For dyke topographic relief >2 m, drying is an obstacle for maintaining the appropriate humidity for the termite colony life. Periodic termite mound spacing is unlikely to be related to dyke or other geological properties. It is more likely related to termite population behaviour, perhaps to clay shortage, which restricts termite population growth by limiting the quantity of building material available for mound extension, and triggers exploration for a new colonization site that will be located along the dyke at a distance from the former colony that may be controlled by the extent of the zone covered by its trail pheromones. This work brings out the importance of dykes in channelling and storing groundwater in semiarid regions, and shows that dykes can store groundwater permanently in such settings even though the dry season is half the year long. It contributes also to shedding light on water supply conditions

  16. HiRISE Observations of Martian Mid-Latitude Fractured Mounds

    NASA Astrophysics Data System (ADS)

    Dundas, C. M.; Mellon, M. T.; McEwen, A. S.; Lefort, A.; Keszthelyi, L. P.; Thomas, N.; HiRISE Team

    2007-12-01

    The High Resolution Imaging Science Experiment (HiRISE) camera has now returned thousands of images of the Martian surface with pixel scale as small as 26 cm/pixel. These have revealed fractured mounds up to several hundred meters in diameter, bearing some morphological resemblance to terrestrial pingos (ice-cored hills formed by freezing groundwater). Pingos on Mars would be valuable indicators of ground ice and have been suggested at a number of sites, but in several cases reexamination has supported different origins. Some differences do exist between the fractured mounds and terrestrial pingos. In several instances, the mounds have roughly trapezoidal topographic profiles with flat, fractured summits. Other morphologies are also seen; we report on the range of morphologies observed so far by HiRISE and similarities and differences with pingos on Earth. The fractured mounds observed to date generally appear in the mid-latitudes, at a range of longitudes. Mars Orbiter Camera (MOC) images of flat-topped mounds in Utopia Planitia (including some previously proposed pingos) show a similar latitudinal dependence, generally occurring between 35-45° N. This supports a ground- ice related origin, particularly since the latitude range is close to the peak-abundance latitude of some other features likely related to water or ice, such as gullies. It is still uncertain whether the formation mechanism of the fractured mounds is the same as terrestrial pingos in detail. We discuss the distribution, properties and settings of fractured mounds observed planet-wide by HiRISE.

  17. Gopher mounds decrease nutrient cycling rates and increase adjacent vegetation in volcanic primary succession.

    PubMed

    Yurkewycz, Raymond P; Bishop, John G; Crisafulli, Charles M; Harrison, John A; Gill, Richard A

    2014-12-01

    Fossorial mammals may affect nutrient dynamics and vegetation in recently initiated primary successional ecosystems differently than in more developed systems because of strong C and N limitation to primary productivity and microbial communities. We investigated northern pocket gopher (Thomomys talpoides) effects on soil nutrient dynamics, soil physical properties, and plant communities on surfaces created by Mount St. Helens' 1980 eruption. For comparison to later successional systems, we summarized published studies on gopher effects on soil C and N and plant communities. In 2010, 18 years after gopher colonization, we found that gophers were active in ~2.5% of the study area and formed ~328 mounds ha(-1). Mounds exhibited decreased species density compared to undisturbed areas, while plant abundance on mound margins increased 77%. Plant burial increased total soil carbon (TC) by 13% and nitrogen (TN) by 11%, compared to undisturbed soils. Mound crusts decreased water infiltration, likely explaining the lack of detectable increases in rates of NO3-N, NH4-N or PO4-P leaching out of the rooting zone or in CO2 flux rates. We concluded that plant burial and reduced infiltration on gopher mounds may accelerate soil carbon accumulation, facilitate vegetation development at mound edges through resource concentration and competitive release, and increase small-scale heterogeneity of soils and communities across substantial sections of the primary successional landscape. Our review indicated that increases in TC, TN and plant density at mound margins contrasted with later successional systems, likely due to differences in physical effects and microbial resources between primary successional and older systems. PMID:25260998

  18. Lithofacies distribution and reservoir heterogeneity within Pennsylvanian phylloid algal mounds, western Orogrande basin, New Mexico

    SciTech Connect

    Giles, K.A.; Soreghan, G.S.

    1996-12-31

    Pennsylvanian strata within the San Andres Mountains (western Orogrande basin) contain very well-developed phylloid algal bioherms, but these bioherms remain understudied owing to their location within the bounds of the U.S. Army White Sands Missile Range. The exposed Upper Pennsylvanian section within Hembrillo Canyon affords a three-dimensional view of mound structure, and thus an excellent opportunity for characterizing lithofacies distribution and reservoir heterogeneity that may prove useful for exploration/exploitation efforts in analogous petroliferous systems. The mounds are developed within a mixed carbonate-clastic shallow marine section punctuated by shoaling-upward cycles. Each mound site consists of a slack of individual biohermal growth events characterized by a subtidal wackestone initiation phase, core boundstone phase, and peritidal to subaerially exposed packstone/grainstone terminal phase. Individual biohermal growth events range up to 30 m in thickness; vertical stacking of these bioherms has produced aggregate mounds reaching up to 100 m in stratigraphic thickness and 300 m in diameter. Individual blohermal thicknesses decrease abruptly and markedly away from mound sites, and calcareous mudstones dominate in intermound regions. The controlling influences of paleogeography and glacioeustasy, respectively, produced the pronounced lateral and vertical heterogeneity characterizing these and analogous phylloid algal mound systems. Reservoirs within these systems are highly compartmentalized: wackestone initiation phases and peritidal to subaerial termination phases that envelope core facies may serve as porosity and permeability barriers that effectively partition the reservoir. Recognition of the scale, character, and probable controls on these lateral and vertical changes is important for effective exploration and exploitation in phylloid algal mound systems.

  19. Lithofacies distribution and reservoir heterogeneity within Pennsylvanian phylloid algal mounds, western Orogrande basin, New Mexico

    SciTech Connect

    Giles, K.A. ); Soreghan, G.S. )

    1996-01-01

    Pennsylvanian strata within the San Andres Mountains (western Orogrande basin) contain very well-developed phylloid algal bioherms, but these bioherms remain understudied owing to their location within the bounds of the U.S. Army White Sands Missile Range. The exposed Upper Pennsylvanian section within Hembrillo Canyon affords a three-dimensional view of mound structure, and thus an excellent opportunity for characterizing lithofacies distribution and reservoir heterogeneity that may prove useful for exploration/exploitation efforts in analogous petroliferous systems. The mounds are developed within a mixed carbonate-clastic shallow marine section punctuated by shoaling-upward cycles. Each mound site consists of a slack of individual biohermal growth events characterized by a subtidal wackestone initiation phase, core boundstone phase, and peritidal to subaerially exposed packstone/grainstone terminal phase. Individual biohermal growth events range up to 30 m in thickness; vertical stacking of these bioherms has produced aggregate mounds reaching up to 100 m in stratigraphic thickness and 300 m in diameter. Individual blohermal thicknesses decrease abruptly and markedly away from mound sites, and calcareous mudstones dominate in intermound regions. The controlling influences of paleogeography and glacioeustasy, respectively, produced the pronounced lateral and vertical heterogeneity characterizing these and analogous phylloid algal mound systems. Reservoirs within these systems are highly compartmentalized: wackestone initiation phases and peritidal to subaerial termination phases that envelope core facies may serve as porosity and permeability barriers that effectively partition the reservoir. Recognition of the scale, character, and probable controls on these lateral and vertical changes is important for effective exploration and exploitation in phylloid algal mound systems.

  20. Evaluating the Role of Hydrocarbon Seepage in Carbonate Mound Formation (Offshore Ireland) using Basin Modelling

    NASA Astrophysics Data System (ADS)

    Naeth, J.; di Primio, R.; Horsfield, B.; Shannon, P.; Bailey, W. R.; Henriet, J. P.

    2003-04-01

    The goal of this project was to assess whether deep water coral mound growth on the continental slope of the north Atlantic could be related to active hydrocarbon leakage. The objects of interest are numerous buried and non-buried carbonate mounds, consisting mainly of corals, carbonate crusts and fine grained clastic sediments in the Porcupine Basin, which is located on the eastern Atlantic continental slope 200 km offshore Ireland and contains the sub-commercial Connemara oil field. To evaluate the possible link between hydrocarbon leakage and mound growth we used 2D and 3D basin modelling in combination with geochemical analysis of sediments from gravity cores. A total of 5 intersecting seismic lines were used as a basis for 2D modelling of basin evolution, hydrocarbon generation and migration. Data from six exploration wells were used for calibration of the basin burial and thermal history using vitrinite reflectance, bottom hole temperatures and apatite fission track data. 3D basin modelling was performed using data provided by UCD in the northern part of the Porcupine Basin. The results of this study indicate that a link between modelled hydrocarbon leakage and carbonate mound growth is possible both in the Belgica mound province on the eastern flank of the basin where stratigraphic pinch outs of carrier beds can lead to the localised leakage of hydrocarbons to the seafloor, as well as in the Hovland Magellan mound area in the northern half of the Porcupine Basin, where small-scale structural closures mapped on the main Miocene surfaces correlate roughly to observed mound locations. This study demonstrates the applicability of basin modelling in testing and identifying geologic processes related to geosphere/biosphere interactions.

  1. A photographic and acoustic transect across two deep-water seafloor mounds, Mississippi Canyon, northern Gulf of Mexico

    USGS Publications Warehouse

    Hart, P.E.; Hutchinson, D.R.; Gardner, J.; Carney, R.S.; Fornari, D.

    2008-01-01

    In the northern Gulf of Mexico, a series of seafloor mounds lie along the floor of the Mississippi Canyon in Atwater Valley lease blocks 13 and 14. The mounds, one of which was drilled by the Chevron Joint Industry Project on Methane Hydrates in 2005, are interpreted to be vent-related features that may contain significant accumulations of gas hydrate adjacent to gas and fluid migration pathways. The mounds are located ???150 km south of Louisiana at ???1300 m water depth. New side-scan sonar data, multibeam bathymetry, and near-bottom photography along a 4 km northwest-southeast transect crossing two of the mounds (labeled D and F) reveal the mounds' detailed morphology and surficial characteristics. Mound D, ???250 m in diameter and 7-10 m in height, has exposures of authigenic carbonates and appears to result from a seafloor vent of slow-to-moderate flux. Mound F, which is ???400 m in diameter and 10-15 m high, is covered on its southwest flank by extruded mud flows, a characteristic associated with moderate-to-rapid flux. Chemosynthetic communities visible on the bottom photographs are restricted to bacterial mats on both mounds and mussels at Mound D. No indications of surficial gas hydrates are evident on the bottom photographs.

  2. Comparison of two carbonate mound sequences in the Lower Ordovician El Paso Formation, west Texas and southern New Mexico

    SciTech Connect

    Clemons, R.E.

    1985-01-01

    The El Paso Formations consists of four members, in ascending order: Hitt Canyon, Jose McKelligon and Padre. Mounds in the McKelligon Member exposed in the southern Franklin Mountains were described by Toomey (1970). Most of these mounds are small but one large one is 5.8 m thick and about 13.7 m long in outcrop. The mound rock is chiefly bioclastic wackestone with minor packstone and boundstone. The varied fauna contains echinoderms, sponges and spicules, gastropods, trilobites, digitate algae, Nuia, Girvanella, Pulchrilamina, Calathium, and minor brachiopods and cephalopods. Intraclastic, bioclastic grainstone fills channels cut in the mounds. Similar, but smaller and less spectacular mounds occur in the McKelligon Member in the Florida, Big Hatchet, and Caballo Mountains, Lone Mountain, Cooke's Range, and elsewhere in southwestern New Mexico. A second type of mound is common in the upper part of the Hitt Canyon Member in the Cooke's Range, Red Hills, Caballo and Big Hatchet Mountains. These mounds also are typically small but one in the Red Hills is 13.7 m thick and about 30 m long in outcrop. The mound complex is about 75-80% SH-C and LLH-C stromatolite boundstone and bioclastic wackestone. The remaining 20-25% is bioclastic packstone and grainstone between the SH-C stromatolites and filling channels cut in the mound complex. The limited fauna contains small fragments of echinoderms, gastropods, trilobites, spicules, and Nuia.

  3. The effect of breakwaters on the structure of marine soft-bottom assemblages: a case study from a North-Western Mediterranean basin.

    PubMed

    Becchi, Claudia; Ortolani, Irene; Muir, Alexander; Cannicci, Stefano

    2014-10-15

    This two-year study is the first attempt to analyse the ecological effects of breakwater systems on soft-bottom assemblages along the North Tyrrhenian coast. Differently from previous studies focusing on infauna of on-shore and off-shore sides, we compared the assemblages inhabiting the surrounding soft-bottoms not directly protected by the breakwaters, defining our sampling stations at varying distances from the breakwaters and at constant distance from the coast. Data collected revealed that abundance, species richness and M-AMBI ecological quality differed between northern and southern sides, and were related to distance from structures. Multivariate analyses of relationships between assemblages and abiotic characteristics support this hypothesis. The extension of these effects, that resulted to be weak and limited to a restricted area, could be a consequence of coastal current on local hydrodynamics. This study provides novel and critical information for the management of the coastal defence infrastructure spreading along the western coast of Italy. PMID:25152186

  4. D-Area Burning/Rubble Pits (431-D and 431-1D) Corrective Measures Study/Focused Feasibility Study

    SciTech Connect

    Palmer, E.R.; Mason, J.T.

    1995-09-01

    The purpose of this report is to determine alternatives which may be used to remediate the D-Area Burning/Rubble Pits (DBRP). An objective of this process is to provide decision makers adequate information to compare alternatives, select an appropriate remediation for the DBRP, and demonstrate the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) requirements in the Record of Decision.

  5. Density of Diadema antillarum (Echinodermata: Echinoidea) on live coral patch reefs and dead Acropora cervicornis rubble patches near Loggerhead Key, Dry Tortugas National Park, Florida, USA

    EPA Science Inventory

    Density of adult Diadema antillarum was assessed on live coral patch reefs and dead Acropora cervicornis rubble patches next to Loggerhead Key, Dry Tortugas National Park, Florida, USA in June 2009. Mean density on live coral patch reefs (0.49 individuals m-2) was not statistical...

  6. Seepage carbonate mounds in Cenozoic sedimentary sequences from the Las Minas Basin, SE Spain

    NASA Astrophysics Data System (ADS)

    Pozo, M.; Calvo, J. P.; Scopelliti, G.; González-Acebrón, L.

    2016-04-01

    A number of carbonate mounds composed of indurate, strongly folded and/or brecciated calcite and dolomite beds occur interstratified in Cenozoic sedimentary sequences from the Las Minas Basin. Part of the fabric of the rock forming the carbonate mounds is composed of laminated to banded dolostone similar to the host rock but showing contrasted lithification. Moreover, the carbonate deposits of the mounds display aggrading neomorphism of dolomite, partial replacement of dolomite by calcite, calcite cementation, and extensive silicification, locally resulting in box-work fabric. Eight main lithofacies were distinguished in the carbonate mound deposits. In some lithofacies, chert is present as both microcrystalline to fibro-radial quartz and opal, the latter occurring mainly as cement whereas the former replace the carbonate and infill voids. Yet one of the carbonate mounds shows distinctive petrography and geochemical features thus suggesting a distinctive growth pattern. The carbon isotope compositions of calcite from the mound samples range from - 11.56 to - 5.15 δ‰ whilst dolomite is depleted in 13C, with values of - 12.38 to 3.02 δ‰. Oxygen isotopic compositions vary from - 9.42 to - 4.64 δ‰ for calcite and between - 6.68 and 8.19 δ‰ for dolomite. Carbonate in the mounds shows significant enrichment in Co, Cr, Ni and Pb content, especially in the strongly deformed (F-2-2 lithofacies) and brecciated carbonate (F-4). The carbonate deposits show depletion in REE and Y in contrast to that determined in lutite. The formation of the carbonate mounds was related to local artesian seepage thermal water flows of moderate to relative high temperatures. Pressure differences between the low permeability host rock and the circulating fluids accounted for dilational fracturing and brecciation of the host sediment packages, which combined with precipitation of new carbonate and silica mineral phases. Locally, some carbonate mounds developed where groundwater

  7. Environmental assessment and planning at Mound - environmental monitoring capabilities and personnel profiles

    SciTech Connect

    1996-07-01

    Through its long experience with radioactive materials, Mound has developed a comprehensive, routine, offsite, environmental surveillance program to safeguard its employees, the physical plant, and the integrity of the surrounding environment from any potential adverse effects of its widely diverse operations. Effluent samples are analyzed for radiological and non-radiological parameters. The environment surrounding Mound Facility is continuously monitored - air, water, foodstuffs, vegetation, soil, and silt samples are analyzed to ensure that radioisotopic concentrations and other possible pollutants are well within the stringent standards adopted by the Department of Energy, the Environmental Protection Agencies (both federal and state), and various regional and local agencies. Moreover, this environmental surveillance program has been designed to ensure that the facility is designed, constructed, managed, operated, and maintained in a manner that continues to meet all federal, state, and local standards for environmental protection. Work in environmental science has been broadened to assess environmental factors associated with various aspects of the National Energy Plan. Both the management and staff at Mound have undertaken a firm commitment to make Mound`s environmental monitoring capabilities available to agencies that have the responsibility for the resolution of important environmental issues.

  8. The character, origin and palaeoenvironmental significance of the Wonderkrater spring mound, South Africa

    NASA Astrophysics Data System (ADS)

    McCarthy, T. S.; Ellery, W. N.; Backwell, L.; Marren, P.; Klerk, B. de; Tooth, S.; Brandt, D.; Woodborne, S.

    2010-08-01

    Wonderkrater is a spring mound consisting entirely of peat in excess of 8 m thick. It has yielded a pollen record extending back over 35,000 years, which has provided one of the very few proxy climatic records for the interior of southern Africa in the Late Pleistocene and Holocene. The current investigation of the morphology and sedimentology of the site has revealed that the peat mound formed due to artesian conditions at the spring, but that accumulation of the thick peat succession was made possible because of clastic sedimentation on the surrounding piedmont which in turn was brought about by aggradation on the adjacent Nyl River floodplain. The peat mound has remained elevated relative to the surrounding piedmont for most of the 35,000 year period. Aggradation of the mound was slower during the Late Pleistocene than the Holocene (0.06-0.1 m/1000 year and 0.2-0.38 m/1000 year, respectively). Controlled archaeological excavations yielded a diverse late Pleistocene fauna preserved in peat and sand in the mound. A 1 m thick, coarse sand horizon at the base of the peat deposit contained a rich Middle Stone Age (>30 k year) lithic assemblage. The MSA sand layer likely represents an arid phase, suggesting the site's antiquity as a place of refuge for Quaternary animals and the people that hunted them.

  9. Aneth oil field carbonate mound reservoir - Organic-rich mudbank origin

    SciTech Connect

    Peterson, J.A. )

    1989-09-01

    The Aneth oil field (approximately 400 million bbl ultimate recovery) occurs within an isolated southeast-northwest-trending Pennsylvanian (Desmoinesian) algal carbonate bank buildup located approximately 25 mi (40 km) basinward of the main carbonate shelf of the Paradox basin in Utah. Desmoinesian deposition was strongly cyclic, with as many as 30 main evaporite-carbonate cycles recognized. The Aneth algal bank is part of the Desert Creek cycle, which is the first cycle above that of the most widespread salt-bearing cycle. The Desert Creek carbonate facies grades basinward to increasingly prevalent evaporite facies, dominated by thick salt beds in the basin center. Within the isolated algal-mound facies, the Desert Creek cycle is characterized by a vertical succession that includes (1) basal black, organic-rich, dolomitic, silty shale, and (2) overlying dark chalky, finely crystalline dolomite which grades upward into (3) the main carbonate mound facies dominated by accumulations of calcareous, leafy green algae with associated brachiopods, fusulinids, small foraminifera, ostracods, and, rarely, corals. Mound buildups are overlain by a relatively thin, black, organic-rich shale unit, the basal bed of the succeeding mound-bearing Ismay cycle. This upper shale unit thickens markedly on the flanks of the Desert Creek and other mounds.

  10. Sedimentation of an upper Pennsylvanian phylloid algal mound complex, Hueco Mountains, El Paso County, TX

    SciTech Connect

    Pol, J.C.

    1984-04-01

    A Late Pennsylvanian mixed carbonate-clastic sequence is exposed in the Hueco Mountains of west Texas. The sequence begins with deposition of a progradational fan-delta system and marine and tidal-flat carbonates. This unit is dominated by calclithite and shale with minor interbeds of shallow-water calcareous mudstone and wackestone. Shallow-water spiculites are commonly associated with these limestones. A thick carbonate unit composed predominantly of limestone overlies the clastics; it was deposited during or just after a major local transgression. The carbonate sediments were deposited on the submerged delta platform in the following sequence: (1) colonization of the shallow platform by rugose corals and early (or syndepositional) cementation of the zone; (2) establishment of shallow-water dasycladacean algal flats; (3) increasing domination of the environment by phylloid algae in response to increasing water depth; (4) accretion of phylloid algal sediments and formation of mounds (directly overlying the dasycladacean algal flats are a number of small mounds formed by accelerated sedimentation within phylloids algal meadows. The high productivity of the phylloid algae and their sediment-trapping ability allowed sedimentation to keep up with sea level rise. Large bioherms resulted, but because of the difference in accretion rates of various mounds, some grew while others were buried by more successful neighbors); and (5) reestablishment of shallow-water dasycladacean algal flats as a result of shoaling of mounds crests and subsequent increase sedimentation in deeper, quieter water on the lee side of the mound complex.

  11. Soil respiration in pits and mounds following an experimental forest blowdown

    SciTech Connect

    Millikin, C.S.; Bowden, R.D.

    1996-11-01

    Extensive uprooting of trees by windthrow can create areas of severe soil disturbance in temperate forests. Specifically, uprooted trees leave shaded pits and mounds of exposed roots and mineral soil. To assess the contribution of pit and mound microenvironments to overall soil respiration in an experimental hurricane blowdown at the Harvard Forest Long-Term Ecological Research site (MA), summer CO{sub 2} effluxes were measured on pit, mound, and undisturbed microsites. Mean CO{sub 2} effluxes were 45.4, 80.1, and 99.0 mgC m{sup -2} h{sup -1} for pit, mound, and control microsites, respectively. Although soil respiration is lower in areas of disturbed soil than in undisturbed areas, the total efflux contribution (5.3%) form pits and mounds to the overall flux rate at the site was small. The area-weighted soil respiration estimate is 3.1% lower than the estimate obtained using flux measurements from control locations alone. Measurements taken from undisturbed plots represent a small but systematic overestimate of soil respiration across the site. 25 refs., 1 fig.

  12. Behavior of subaqueous sediment mounds: Effect on dredged material disposal site capacity

    SciTech Connect

    Poindexter, M.E.

    1988-01-01

    Dredging of contaminated sediments and subsequent disposal at legally designated disposal sites is an internationally accepted disposal alternative when adherence to strict disposal practices is maintained. As more highly contaminated sediments in the heavily industrialized harbors of the world must be dredged to maintain navigation and economic viability, use of subaqueous dredged material disposal sites is expected to increase. Use of these subaqueous sites has necessitated development of procedures to analyze disposal site capacity based upon physical, chemical, and biological considerations. A methodology of analysis was developed in this study to investigate the behavior of the crated subaqueous sediment mounds. Emphasis was placed upon the geotechnical engineering aspects of mound behavior although the methodology also includes chemical and biological aspects. This methodology was applied to four field sites at which dredged material mounds have been created. The procedure successfully predicted the geotechnical engineering behavior of the constructed dredged material mounds. This methodology of analysis provides a useful tool for evaluation of subaqueous disposal sites and the dredged materials mounds created within these sites.

  13. Geochemical characteristics and early diagenesis of recent carbonate mound sediments in the Gulf of Cadiz

    NASA Astrophysics Data System (ADS)

    Hamaekers, Helen; Foubert, Anneleen; Wienberg, Claudia; Hebbeln, Dierk; Swennen, Rudy

    2010-05-01

    Cold-water coral carbonate mounds occur in patches along the continental margin of the North Atlantic Ocean, from northern Norway down to Mauretania. Recent research has been focused on carbonate mounds in the Gulf of Cadiz, especially along the Moroccan margin. The Pen Duick, the Renard and the Vernadsky carbonate mound provinces in the Gulf of Cádiz are only some of the mound provinces which have been the subject of several recent research projects (Foubert et al., 2008; Wienberg et al., 2009). No living scleractinians could be found on top of those carbonate mounds. During cruise 64PE284 of RV Pelagia, gravity cores have been taken through carbonate mounds in the Carbonate Mound Provinces (CMP) SE of Yuma mud volcano and N of Meknes mud volcano. These cores have been analysed by several methods such as Magnetic Susceptibility (MS), X-Ray Fluorescence (XRF), Inductive Coupled Plasma Optical Emission Spectroscopy (ICP-OES) and X-Ray Diffraction (XRD) to determine the geochemical characteristics of carbonate mounds, which can be used to quantify the effects of early diagenetic processes which may have altered the palaeo-environmental characteristics of the carbonate mounds. Dating has been done with 14C and U/Th methods pointing to mound growth phases being restricted to glacial periods. XRF and ICP-OES measurements give both qualitative and quantitative data of the chemical composition of the core. The main elements that have been analysed are Ca, Si, Fe, Sr, Al, K, Mg, Ti. According to the trend they follow, they can be devided in two groups, representative for the two encountered fraction types. These two fraction types (biogenic carbonate-rich fraction and terrigenous silicate-rich fraction) can be coupled to interglacial/glacial palaeo-environmental conditions. XRD measurements give an overview of the mineralogical composition of the cores. Thin sections, analysed by cathodeluminescence and classical optical petrography, and micro-CT scans are used to

  14. Distribution and physical traits of red wood ant mounds in a managed Rhodope mountains forest.

    PubMed

    Tsikas, Angelos; Karanikola, Paraskevi; Papageorgiou, Aristotelis C

    2016-07-01

    Red wood ants (RWA) are of great ecological importance for the forest ecosystem. Forestry practices, like clear-cutting, and trampling load, due to tourism, logging, and grazing stock, can greatly affect their colonies, disturbing their microhabitat. RWA in Greek forests have not been investigated so far. We herein report on the distribution and morphological traits of Formica lugubris mounds studied in Elatia forest (Rhodope mountains, Northern Greece), an all-aged managed mixed forest where selective logging practices are performed. Nearby vegetation, slope, canopy cover, shrub density, and distance from the nearest neighboring trees were also recorded. Mound density was shown to be much higher in this Greek forest compared to RWA mounds in other European-managed forests. Furthermore, we recorded a continuous nest establishment, despite forest management disturbances and trampling load. Our study suggests that single-tree selective forestry practices are essential for creating ideal microhabitats for the RWA and, therefore, for maintaining RWA populations. PMID:27345521

  15. Internal structure of segment reefs: Halimeda algal mounds in the Mediterranean Miocene

    NASA Astrophysics Data System (ADS)

    Braga, Juan C.; Martín, José M.; Riding, Robert

    1996-01-01

    Halimeda reefs in the upper Miocene strata (˜6 Ma) of the Sorbas basin, southeastern Spain, shed light on the internal structure of more extensive but less accessible Holocene counterparts, and challenge conventional reef concepts. Coarse discoid segments, released by Halimeda during life or immediately after death, dominate the lenslike mounds. Their chaotic, loose appearance disguises the reefal nature of the mounds. Segments, accumulating at or very close to sites of growth, were quickly stabilized by microbial and cement crusts that bound them into distinctive rigid gravel fabrics. This early lithification generated relief but inhibited off-mound export of sediment, although large blocks detached locally and moved downslope. Encrustation of parautochthonous Halimeda gravel created a unique reef type: segment reefs.

  16. Conversion of the Bryan Mound geological site characterization reports to a three-dimensional model.

    SciTech Connect

    Stein, Joshua S.; Rautman, Christopher Arthur

    2005-04-01

    The Bryan Mound salt dome, located near Freeport, Texas, is home to one of four underground crude oil-storage facilities managed by the U. S. Department of Energy Strategic Petroleum Reserve (SPR) Program. Sandia National Laboratories, as the geotechnical advisor to the SPR, conducts site-characterization investigations and other longer-term geotechnical and engineering studies in support of the program. This report describes the conversion of two-dimensional geologic interpretations of the Bryan Mound site into three-dimensional geologic models. The new models include the geometry of the salt dome, the surrounding sedimentary units, mapped faults, and the 20 oil-storage caverns at the site. This work provides an internally consistent geologic model of the Bryan Mound site that can be used in support of future work.

  17. Analysis of cavern stability at the Bryan Mound SPR site.

    SciTech Connect

    Ehgartner, Brian L.; Sobolik, Steven Ronald

    2009-04-01

    This report presents computational analyses that simulate the structural response of caverns at the Strategic Petroleum Reserve Bryan Mound site. The cavern field comprises 20 caverns. Five caverns (1, 2, 4, and 5; 3 was later plugged and abandoned) were acquired from industry and have unusual shapes and a history dating back to 1946. The other 16 caverns (101-116) were leached according to SPR standards in the mid-1980s and have tall cylindrical shapes. The history of the caverns and their shapes are simulated in a 3-D geomechanics model of the site that predicts deformations, strains, and stresses. Future leaching scenarios due to oil drawdowns using fresh water are also simulated by increasing the volume of the caverns. Cavern pressures are varied in the model to capture operational practices in the field. The results of the finite element model are interpreted to provide information on the current and future status of subsidence, well integrity, and cavern stability. The most significant result in this report is relevant to caverns 1, 2, and 5. The caverns have non-cylindrical shapes and have potential regions where the surrounding salt may be damaged during workover procedures. During a workover the normal cavern operating pressure is lowered to service a well. At this point the wellhead pressures are atmospheric. When the workover is complete, the cavern is repressurized. The resulting elastic stresses are sufficient to cause tension and large deviatoric stresses at several locations. With time, these stresses relax to a compressive state due to salt creep. However, the potential for salt damage and fracturing exists. The analyses predict tensile stresses at locations with sharp-edges in the wall geometry, or in the case of cavern 5, in the neck region between the upper and lower lobes of the cavern. The effects do not appear to be large-scale, however, so the only major impact is the potential for stress-induced salt falls in cavern 5, potentially leading to

  18. Antarctic Mirabilite Mounds as Mars Analogs: The Lewis Cliffs Ice Tongue Revisited

    NASA Technical Reports Server (NTRS)

    Socki, Richard A.; Sun, Tao; Niles, Paul B.; Harvey, Ralph P.; Bish, David L.; Tonui, Eric

    2012-01-01

    It has been proposed, based on geomorphic and geochemical arguments, that subsurface water has played an important role in the history of water on the planet Mars [1]. Subsurface water, if present, could provide a protected and long lived environment for potential life. Discovery of gullies [2] and recurring slopes [3] on Mars suggest the potential for subsurface liquid water or brines. Recent attention has also focused on small (< approx. 1km dia.) mound-like geomorphic features discovered within the mid to high latitudes on the surface of Mars which may be caused by eruptions of subsurface fluids [4, 5]. We have identified massive but highly localized Na-sulfate deposits (mirabilite mounds, Na2SO4 .10H2O) that may be derived from subsurface fluids and may provide insight into the processes associated with subsurface fluids on Mars. The mounds are found on the end moraine of the Lewis Cliffs Ice Tongue (LCIT) [6] in the Transantarctic Mountains, Antarctica, and are potential terrestrial analogs for mounds observed on the martian surface. The following characteristics distinguish LCIT evaporite mounds from other evaporite mounds found in Antarctic coastal environments and/or the McMurdo Dry Valleys: (1) much greater distance from the open ocean (approx.500 km); (2) higher elevation (approx.2200 meters); and (3) colder average annual temperature (average annual temperature = -30 C for LCIT [7] vs. 20 C at sea level in the McMurdo region [8]. Furthermore, the recent detection of subsurface water ice (inferred as debris-covered glacial ice) by the Mars Reconnaissance Orbiter [9] supports the use of an Antarctic glacial environment, particularly with respect to the mirabilite deposits described in this work, as an ideal terrestrial analog for understanding the geochemistry associated with near-surface martian processes. S and O isotopic compositions.

  19. Late Pleistocene bryozoan reef mounds of the Great Australian Bight: Isotope stratigraphy and benthic foraminiferal record

    NASA Astrophysics Data System (ADS)

    Holbourn, Ann; Kuhnt, Wolfgang; James, Noel

    2002-08-01

    Cores from Sites 1129, 1131, and 1132 (Ocean Drilling Program (ODP) Leg 182) on the uppermost slope at the edge of the continental shelf in the Great Australian Bight reveal the existence of upper Pleistocene bryozoan reef mounds, previously only detected on seismic lines. Benthic foraminiferal oxygen isotope data for the last 450,000 years indicate that bryozoan reef mounds predominantly accumulated during periods of lower sea level and colder climate since stage 8 at Sites 1129 and 1132 and since stage 4 at the deeper Site 1131. During glacials and interstadials (stages 2-8) the combination of lowered sea level, increased upwelling, and absence of the Leeuwin Current probably led to an enhanced carbon flux at the seafloor that favored prolific bryozoan growth and mound formation at Site 1132. At Site 1129, higher temperatures and downwelling appear to have inhibited the full development of bryozoan mounds during stages 2-4. During that time, favorable hydrographic conditions for the growth of bryozoan mounds shifted downslope from Site 1129 to Site 1131. Superimposed on these glacial-interglacial fluctuations is a distinct long-term paleoceanographic change. Prior to stage 8, benthic foraminiferal assemblages indicate low carbon flux to the seafloor, and bryozoan mounds, although present closer inshore, did not accumulate significantly at Sites 1129 and 1132, even during glacials. Our results show that the interplay of sea level change (eustatic and local, linked to platform progradation), glacial-interglacial carbon flux fluctuations (linked to local hydrographic variations), and possibly long-term climatic change strongly influenced the evolution of the Great Australian Bight carbonate margin during the late Pleistocene.

  20. Sedimentation patterns on a cold-water coral mound off Mauritania

    NASA Astrophysics Data System (ADS)

    Eisele, Markus; Frank, Norbert; Wienberg, Claudia; Titschack, Jürgen; Mienis, Furu; Beuck, Lydia; Tisnerat-Laborde, Nadine; Hebbeln, Dierk

    2014-01-01

    An unconformity-bound glacial sequence (135 cm thick) of a coral-bearing sediment core collected from the flank of a cold-water coral mound in the Banda Mound Province off Mauritania was analysed. In order to study the relation between coral framework growth and its filling by hemipelagic sediments, U-series dates obtained from the cold-water coral species Lophelia pertusa were compared to 14C dates of planktonic foraminifera of the surrounding matrix sediments. The coral ages, ranging from 45.1 to 32.3 ka BP, exhibit no clear depositional trend, while on the other hand the 14C dates of the matrix sediment provide ages within a much narrower time window of <3000 yrs (34.6-31.8 cal ka BP), corresponding to the latest phase of the coral growth period. In addition, high-resolution computer tomography data revealed a subdivision of the investigated sediment package into three distinct parts, defined by the portion and fragmentation of corals and associated macrofauna as well as in the density of the matrix sediments. Grain size spectra obtained on the matrix sediments show a homogeneous pattern throughout the core sediment package, with minor variations. These features are interpreted as indicators of redeposition. Based on the observed structures and the dating results, the sediments were interpreted as deposits of a mass wasting event, namely a debris flow. During this event, the sediment unit must have been entirely mixed; resulting in averaging of the foraminifera ages from the whole unit and giving randomly distributed coral ages. In this context, for the first time mass wasting is proposed to be a substantial process of mound progradation by exporting material from the mound top to the flanks. Hence, it may not only be an erosional feature but also widening the base of the mound, thus allowing further vertical mound growth.

  1. Can mima-like mounds be Vertisol relics (Far North Region of Cameroon, Chad Basin)?

    NASA Astrophysics Data System (ADS)

    Diaz, Nathalie; Dietrich, Fabienne; Cailleau, Guillaume; Sebag, David; Ngounou Ngatcha, Benjamin; Verrecchia, Eric P.

    2016-05-01

    Non-anthropogenic earth mounds, defined as mima-like mounds in this study, have recently been observed in non-carbonate watersheds along the Sudano-Sahelian belt in the Chad Basin. In the Diamare piedmont (northern Cameroon) they are particularly well developed within stream networks. In less eroded areas, they occur as whaleback, flattened morphologies, or even as buried features. All these shapes are composed of clay-rich sediment associated with high proportions of secondary carbonate nodules and Fesbnd Mn micro-nodules. Their soil structure is prismatic to massive and vertical cracks are observed locally. Grain-size distributions emphasize the clay-rich nature of the sediment, with average clay contents of 32% ± 12.8% (n = 186), which is significantly higher than the clay content in the adjacent sediments in the landscape (mean = 10% ± 4%, n = 21). Moreover, high proportions of smectite characterize the soil, with average contents of 34 ± 7% (n = 25). At the micro-scale, the groundmass has a cross-striated b-fabric, with embedded smooth subangular quartz and feldspar grains of the silt-size fraction. All the characteristics point to altered vertic properties in the clay-rich sediment composing the mima-like mounds. Mima-like mounds are thus interpreted as degraded Vertisols. Compared to present-day Vertisols occurring in the piedmont, mima-like mounds are located upstream. It is thus proposed that the Vertisol areas were more extensive during a former and wetter period than the present-day. Subsequent changing climatic conditions increased erosion, revealing the gilgai micro-relief by preferential erosion in micro-lows rather than in micro-highs. Mima-like mounds of the Chad Basin might thus result from pedogenesis combined with later erosion. These local processes can be inherited from regional climatic variations during the Late Pleistocene-Holocene and likely be related to the African Humid Period.

  2. Seasonal Dynamics of Hyperspectral Reflectance Patterns Influencing Detection of Imported Fire Ant (Hymenoptera: Formicidae) Mound Features in Turfgrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive mound-building imported fire ants impact soil quality and turfgrass nutrient management affecting an estimated 8.1 million hectares in sod production, recreational, and residential settings in the southeastern U.S. Reflectance characteristics of imported fire ant mound features (i.e., ant m...

  3. Subsurface microbiology and biogeochemistry of a deep, cold-water carbonate mound from the Porcupine Seabight (IODP Expedition 307)

    PubMed Central

    Webster, Gordon; Blazejak, Anna; Cragg, Barry A; Schippers, Axel; Sass, Henrik; Rinna, Joachim; Tang, Xiaohong; Mathes, Falko; Ferdelman, Timothy G; Fry, John C; Weightman, Andrew J; Parkes, R John

    2009-01-01

    The Porcupine Seabight Challenger Mound is the first carbonate mound to be drilled (∼270 m) and analyzed in detail microbiologically and biogeochemically. Two mound sites and a non-mound Reference site were analyzed with a range of molecular techniques [catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH), quantitative PCR (16S rRNA and functional genes, dsrA and mcrA), and 16S rRNA gene PCR-DGGE] to assess prokaryotic diversity, and this was compared with the distribution of total and culturable cell counts, radiotracer activity measurements and geochemistry. There was a significant and active prokaryotic community both within and beneath the carbonate mound. Although total cell numbers at certain depths were lower than the global average for other subseafloor sediments and prokaryotic activities were relatively low (iron and sulfate reduction, acetate oxidation, methanogenesis) they were significantly enhanced compared with the Reference site. In addition, there was some stimulation of prokaryotic activity in the deepest sediments (Miocene, > 10 Ma) including potential for anaerobic oxidation of methane activity below the mound base. Both Bacteria and Archaea were present, with neither dominant, and these were related to sequences commonly found in other subseafloor sediments. With an estimate of some 1600 mounds in the Porcupine Basin alone, carbonate mounds may represent a significant prokaryotic subseafloor habitat. PMID:18826439

  4. Experimental explanation of the formation mechanism of surface mound-structures by femtosecond laser on polycrystalline Ni60Nb40

    NASA Astrophysics Data System (ADS)

    Peng, Edwin; Tsubaki, Alfred; Zuhlke, Craig A.; Wang, Meiyu; Bell, Ryan; Lucis, Michael J.; Anderson, Troy P.; Alexander, Dennis R.; Gogos, George; Shield, Jeffrey E.

    2016-01-01

    Femtosecond laser surface processing (FLSP) is an emerging technique for creating functionalized surfaces with specialized properties, such as broadband optical absorption or superhydrophobicity/superhydrophilicity. It has been demonstrated in the past that FLSP can be used to form two distinct classes of mound-like, self-organized micro/nanostructures on the surfaces of various metals. Here, the formation mechanisms of below surface growth (BSG) and above surface growth (ASG) mounds on polycrystalline Ni60Nb40 are studied. Cross-sectional imaging of these mounds by focused ion beam milling and subsequent scanning electron microscopy revealed evidence of the unique formation processes for each class of microstructure. BSG-mound formation during FLSP did not alter the microstructure of the base material, indicating preferential valley ablation as the primary formation mechanism. For ASG-mounds, the microstructure at the peaks of the mounds was clearly different from the base material. Transmission electron microscopy revealed that hydrodynamic melting of the surface occurred during FLSP under ASG-mound forming conditions. Thus, there is a clear difference in the formation mechanisms of ASG- and BSG-mounds during FLSP.

  5. Pre-Columbian landscape impact and agriculture in the Monumental Mound region of the Llanos de Moxos, lowland Bolivia

    NASA Astrophysics Data System (ADS)

    Whitney, Bronwen S.; Dickau, Ruth; Mayle, Francis E.; Soto, J. Daniel; Iriarte, José

    2013-09-01

    We present a multiproxy study of land use by a pre-Columbian earth mounds culture in the Bolivian Amazon. The Monumental Mounds Region (MMR) is an archaeological sub-region characterized by hundreds of pre-Columbian habitation mounds associated with a complex network of canals and causeways, and situated in the forest-savanna mosaic of the Llanos de Moxos. Pollen, phytolith, and charcoal analyses were performed on a sediment core from a large lake (14 km2), Laguna San José (14°56.97'S, 64°29.70'W). We found evidence of high levels of anthropogenic burning from AD 400 to AD 1280, corroborating dated occupation layers in two nearby excavated habitation mounds. The charcoal decline pre-dates the arrival of Europeans by at least 100 yr, and challenges the notion that the mounds culture declined because of European colonization. We show that the surrounding savanna soils were sufficiently fertile to support crops, and the presence of maize throughout the record shows that the area was continuously cultivated despite land-use change at the end of the earth mounds culture. We suggest that burning was largely confined to the savannas, rather than forests, and that pre-Columbian deforestation was localized to the vicinity of individual habitation mounds, whereas the inter-mound areas remained largely forested.

  6. Archaeomagnetic study of ancient slag mounds in Cyprus: continuous paleointensity curves in high resolution

    NASA Astrophysics Data System (ADS)

    Shaar, R.; Tauxe, L.; Ben-Yosef, E.; Levy, T. E.; Kassianidou, V.; Lorentzen, B. E.

    2012-12-01

    One of the main challenges in paleointensity research is obtaining continuous high-resolution records that describe the behavior of the geomagnetic field on short time scales. One difficulty in obtaining such records is the problem of precise dating of suitable samples. Another fundamental difficulty is the assessment of the uncertainty involved in the interpretation of paleointensity experiments. Here we present an archaeomagnetic study of ancient slag mounds, which is designed to minimize these difficulties. We study two archaeological slag mounds in the Troodos foothills of Cyprus; one from the massive Roman mines at Skouriotissa, and another pre Roman near Mitsero Kokkinoyia. The mounds consist of industrial layers of copper slag intermixed with charcoal, which were deposited during times of intense copper smelting activity. The slag mound at Skouriotissa represents one of the largest copper production sites in the ancient world, including a 25 m high section and more than 40 archaeological layers. The mound at Mitsero is ca. 10 m high and contains about 32 layers. Hundreds of slag samples and associated charcoals from both mounds were collected, from which more than 600 slag specimens from more than 150 individual samples were analyzed for paleointensity. In addition,19 charcoals were radiocarbon dated. To minimize the uncertainty in the radiocarbon dating we applied a Bayesian model for each mound, which takes into account the relative stratigraphy of the layers. To reduce the uncertainty involved in the subjective interpretation of the paleointensity experiments (conventionally done by manually selecting temperature bounds in the Arai plot of each specimen) we designed new optimization software. The optimization software uses the assumption that paleointensity estimates from samples that were collected from the same level, should be similar. The optimization algorithm finds the selecting criteria that yields minimum scatter within each level, assigns

  7. Overview of the earth mounded concrete bunker prototype license application project: Objectives and approach

    SciTech Connect

    Conner, J.E.

    1989-11-01

    This paper presents an overview of the objectives and approach taken in developing the Earth-mounded Concrete Bunker Prototype License Application Project. The Prototype License Application Project was initiated by the Department of Energy`s National Low-Level Waste Management Program in early 1987 and completed in November 1988. As part of this project a prototype safety analysis report was developed. The safety analysis report evaluates the licensibility of an earth-mounded concrete bunker for a low-level radioactive waste (LLW) disposal facility located on a hypothetical site in the northeastern United States. The project required approximately five person-years and twenty months to develop.

  8. Methane fluxes, microbes and carbonate mounds: insights from asin modelling of the porcupine basin, ireland

    NASA Astrophysics Data System (ADS)

    Naeth, J.; di Primio, R.; Schäfer, R. G.; Horsfield, B.

    2003-04-01

    Our broad task has been to investigate the origin and growth of large carbonate mounds within the Porcupine Basin offshore Ireland. Specifically, the project aims at determining the timing and magnitude of chemical degradation and physical redistribution processes which are likely to have played a key role in the formation of carbonate mounds. We addressed these issues using 2D basin modelling the results of which were used for map-based migration modelling. The overall sedimentary basin architecture of the basin facilitates up-dip fluid migration towards the western, eastern and especially the northern margins of the basin. Potential fluid migration pathways are available through a variety of stratal surfaces, unconformities, faults and detachments. The spatial association of deep water carbonate mounds with underlying fluid pathways is compatible with the provision of a basin-derived nutrient source (e.g. hydrocarbons). Numerical simulations lie at the centre of the investigation using three seismic lines covering the Hovland-Magellan mound area in the northern part of the basin and the Belgica mound area in the western part. The calibration of the thermal history was performed by iteratively using putative heat-flow scenarios in compliance with the known geologic evolution of the basin, present-day temperatures, organic maturity parameters, overpressure occurrence and assigned lithologies. After optimisation of the model, the generation and migration history of potential source units were modelled using, inter alia, the source richness and quality assignments referred to above and kinetic parameters of hydrocarbon generation determined experimentally. The results achieved indicate that: bullet hydrocarbon generation and expulsion is currently taking place in the vicinity of the mound locations bullet stratigraphic pinch outs and shallow structural closures underly most mounds bullet a high temporal and spatial resolution of the latest Tertiary and Quaternary

  9. A seismic reflection velocity study of a Mississippian mud-mound in the Illinois basin

    NASA Astrophysics Data System (ADS)

    Ranaweera, Chamila Kumari

    Two mud-mounds have been reported in the Ullin limestone near, but not in, the Aden oil field in Hamilton County, Illinois. One mud-mound is in the Broughton oil field of Hamilton County 25 miles to the south of Aden. The second mud-mound is in the Johnsonville oil field in Wayne County 20 miles to the north of Aden. Seismic reflection profiles were shot in 2012 adjacent to the Aden oil field to evaluate the oil prospects and to investigate the possibility of detecting Mississippian mud-mounds near the Aden field. A feature on one of the seismic profiles was interpreted to be a mud-mound or carbonate buildup. A well drilled at the location of this interpreted structure provided digital geophysical logs and geological logs used to refine the interpretation of the seismic profiles. Geological data from the new well at Aden, in the form of drill cuttings, have been used to essentially confirm the existence of a mud-mound in the Ullin limestone at a depth of 4300 feet. Geophysical well logs from the new well near Aden were used to create 1-D computer models and synthetic seismograms for comparison to the seismic data. The reflection seismic method is widely used to aid interpreting subsurface geology. Processing seismic data is an important step in the method as a properly processed seismic section can give a better image of the subsurface geology whereas a poorly processed section could mislead the interpretation. Seismic reflections will be more accurately depicted with careful determination of seismic velocities and by carefully choosing the processing steps and parameters. Various data processing steps have been applied and parameters refined to produce improved stacked seismic records. The resulting seismic records from the Aden field area indicate a seismic response similar to what is expected from a carbonate mud-mound. One-dimensional synthetic seismograms were created using the available sonic and density logs from the well drilled near the Aden seismic lines

  10. The early diagenetic and PETROphysical behaviour of recent cold-water CARbonate mounds in Deep Environments (PETROCARDE)

    NASA Astrophysics Data System (ADS)

    Foubert, Anneleen; Pirlet, Hans; Thierens, Mieke; de Mol, Ben; Henriet, Jean-Pierre; Swennen, Rudy

    2010-05-01

    Sub-recent cold-water carbonate mounds localized in deeper slope settings on the Atlantic continental margins cannot be any longer neglected in the study of carbonate systems. They clearly play a major role in the dynamics of mixed siliciclastic-carbonate and/or carbonate-dominated continental slopes. Carbonate accumulation rates of cold-water carbonate mounds are about 4 to 12 % of the carbonate accumulation rates of tropical shallow-water reefs but exceed the carbonate accumulation rates of their slope settings by a factor of 4 to 12 (Titschack et al., 2009). These findings emphasize the importance of these carbonate factories as carbonate niches on the continental margins. The primary environmental architecture of such carbonate bodies is well-characterized. However, despite proven evidences of early diagenesis overprinting the primary environmental record (e.g. aragonite dissolution) (Foubert & Henriet, 2009), the extent of early diagenetic and biogeochemical processes shaping the petrophysical nature of mounds is until now not yet fully understood. Understanding (1) the functioning of a carbonate mound as biogeochemical reactor triggering early diagenetic processes and (2) the impact of early diagenesis on the petrophysical behaviour of a carbonate mound in space and through time are necessary (vital) for the reliable prediction of potential late diagenetic processes. Approaching the fossil carbonate mound record, through a profound study of recent carbonate bodies is innovative and will help to better understand processes observed in the fossil mound world (such as cementation, brecciation, fracturing, etc…). In this study, the 155-m high Challenger mound (Porcupine Seabight, SW of Ireland), drilled during IODP Expedition 307 aboard the R/V Joides Resolution (Foubert & Henriet, 2009), and mounds from the Gulf of Cadiz (Moroccan margin) will be discussed in terms of early diagenetic processes and petrophysical behaviour. Early differential diagenesis

  11. A large-scale middle Miocene carbonate (?) mound structure in the Norwegian-Danish Basin: evidence for hydrocarbon migration?

    NASA Astrophysics Data System (ADS)

    Andresen, K. J.; Clausen, O. R.; Huuse, M.

    2007-12-01

    A mounded structure has been observed in the Norwegian-Danish Basin about 10 km east of the Coffee Soil Fault outside the Central Graben and almost directly on top of the mid-Miocene unconformity. The mounded structure has been mapped using 3D seismic data; it consists of two culminations arranged in a triangular area; one is 1500 m long, 800 m wide and 70 m high while the other is 800 m long, 400 m wide and 30 m high. The composite mound comprises a volume of some 29 mio m3 and is characterised by a high positive reflection amplitude at the top, differential compaction as compared to the surrounding sediments and velocity pull up in underlying reflections. These observations indicate a high velocity fill with higher acoustic impedance and less compaction than that of the surrounding sediments, and the interior of the mounded structure has thus been interpreted as a relatively hard, coarse grained or well cemented sediment. The observed mound is an isolated feature and there have been no reports on any similar structures in the surrounding area. Several possible morphological mound-shaped features have been considered such as igneous and clastic intrusions and extrusions, mud volcanoes, contourites, turbidites and carbonate mounds. The succession below the mound shows no vertical disturbance such as seismic chimneys or deformation of layers, and this seems to exclude an extrusive origin, which most likely would have had some influence on the sedimentary succession. Investigation of the base reflection in the surrounding area shows no sign of any erosional features such as submarine channels and this appears to exclude an origin as a turbidite or contourite since these features often are associated with some kind of erosion. Large present day seismic chimneys have been found in close proximity to the mound along with numerous elongated pockmarks in the Miocene succession right above the mound. These observations indicate that the study area is highly influenced by

  12. Mapping the fluid flow of the Mariana Mounds ridge flank hydrothermal system: Pore water chemical tracers

    NASA Astrophysics Data System (ADS)

    Wheat, C. Geoffrey; McDuff, Russell E.

    1995-01-01

    We present a conceptual model of fluid circulation in a ridge flank hydrothermal system, the Mariana Mounds. The model is based on chemical data from pore waters extracted from piston cores and from push cores collected by deep-sea research vessel Alvin in small, meter-sized mounds situated on a local topographic high. These mounds are located within a region of heat flow exceeding that calculated from a conductive model and are zones of strong pore water upflow. We have interpreted the chemical data with time-dependent transport-reaction models to estimate pore water velocities. In the mounds themselves pore water velocities reach several meters per year to kilometers per year. Within about 100 m from these zones of focused upflow velocities decrease to several centimeters per year up to tens of centimeters per year. A larger area of low heat flow surrounds these heat flow and topographic highs, with upwelling pore water velocities less than 2 cm/yr. In some nearby cores, downwelling of bottom seawater is evident but at speeds less than 2 cm/yr. Downwelling through the sediments appears to be a minor source of seawater recharge to the basaltic basement. We conclude that the principal source of seawater recharge to basement is where basement outcrops exist, most likely a scarp about 2-4 km to the east and southeast of the study area.

  13. Marketing research for EE G Mound Applied Technologies' heat treatment process of high strength materials

    SciTech Connect

    Shackson, R.H.

    1991-10-09

    This report summarizes research conducted by ITI to evaluate the commercialization potential of EG G Mound Applied Technologies' heat treatment process of high strength materials. The remainder of the report describes the nature of demand for maraging steel, extent of demand, competitors, environmental trends, technology life cycle, industry structure, and conclusion. (JL)

  14. Seasonal Shifts in the Hyperspectral Characterization of Imported Fire Ant (Hymenoptera: Formicidae) Mound Features in Turfgrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Safe, expedient, and cost-effective field- to landscape-scale treatments of imported fire ant (IFA) infestations require technological developments that exploit the use of remotely-sensed contrasting features to detect cryptic mounds in heavily-managed turfgrass. Ground-based implementation of hyper...

  15. Effects of simulated and natural rainfall on summer mound construction by imported fire ants (Hymenoptera: Formicidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Imported fire ant (Solenopsis richteri x invicta) mounds in northeastern Mississippi were subjected to four treatments from late July through early September, 2006: application of water (7.5 L) and placement of an inverted 19 L bucket on top; application of water only; application of an inverted buc...

  16. SEASONAL SHIFTS IN THE HYPERSPECTRAL CHARACTERIZATION OF IMPORTED FIRE ANT (HYMENOPTERA: FORMICIDAE) MOUND FEATURES IN TURFGRASS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Safe, expedient, and cost-effective field- to landscape-scale treatments of imported fire ant (IFA) infestations require technological developments that exploit the use of remotely-sensed contrasting features to detect cryptic mounds in heavily-managed turfgrass. Ground-based implementation of hyper...

  17. Stable isotope sales: Mound Facility customer and shipment summaries, FY 1981

    SciTech Connect

    Ruwe, Jr, A H

    1982-10-01

    A listing is given of Mound Facility's sales of stable isotopes of noble gases, carbon, oxygen, nitrogen, chlorine, and sulfur for Fiscal Year 1981. Purchasers are listed alphabetically and are divided into domestic and foreign groups. A cross-reference index by location is included for domestic customers. Cross-reference listings by isotope purchased are included for all customers.

  18. Cultural Symbolism behind the Architectural Design of Mounds Park All-Nations Magnet School.

    ERIC Educational Resources Information Center

    Pewewardy, Cornell; May, Paul G.

    1992-01-01

    The architectural design of Mounds Park All-Nations Magnet School (St. Paul, Minnesota) incorporates cultural symbols representing the Native American worldview and Medicine Wheel Circle beliefs, as well as design elements from aboriginal housing styles, and colors and sculptured elements that reinforce the relationship of nature to building. (SV)

  19. Mapping the fluid flow of the Mariana Mounds ridge flank hydrothermal system: Pore water chemical tracers

    SciTech Connect

    Wheat, C.G.; McDuff, R.E.

    1995-05-10

    The authors present a conceptual model of fluid circulation in a ridge flank hydrothermal system, the Mariana Mounds. The model is based on chemical data from pore waters extracted from piston cores and from push cores collected by deep-sea research vessel Alvin in small, meter-sized mounds situated on a local topographic high. These mounds are located within a region of heat flow exceeding that calculated from a conductive model and are zones of strong pore water upflow. The authors have interpreted the chemical data with time-dependent transport-reaction models to estimate pore water velocities. In the mounds themselves pore water velocities reach several meters per year to kilometers per year. Within about 100 m from these zones of focused upflow velocities decrease to several centimeters per year up to tens of centimeters per year. A large area of low heat flow surrounds these heat flow and topographic highs, with upwelling pore water velocities less than 2 cm/yr. In some nearby cores, downwelling of bottom seawater is evident but at speeds less than 2 cm/yr. Downwelling through the sediments appears to be a minor source of seawater recharge to the basaltic basement. The authors conclude that the principal source of seawater recharge to basement is where basement outcrops exist, most likely a scarpt about 2-4 km to the east and southeast of the study area. 71 refs., 14 figs., 3 tabs.

  20. Carbonate mounds from the Gulf of Cadiz in relation to methane seepage: unrelated phenomena or coupling?

    NASA Astrophysics Data System (ADS)

    Stadnitskaia, Alina; Baas, Marianne; de Haas, Henk; van Weering, Tjeerd C. E.; Kreulen, Rob R.; Sinninghe Damsté, Jaap S.

    2010-05-01

    For more than decade, the formation of carbonate mounds, related ecosystem development and organization/functioning of the entire mound habitats are subjects for a growing amount of studies and discussions. Carbonate mounds from the Gulf of Cadiz are of special interest due to their association with active mud volcanoes within the El Arraiche mud volcano field. Such co-occurrence of ecologically contrasting phenomena anticipates complex biogeochemical interactions between a carbonate mound interior and seeping through hydrocarbon-rich fluids. To get closer in understanding of how methane affects a carbonate mound development in the gulf, a combination of inorganic and organic geochemical techniques was applied to two sedimentary cores collected from summits of Alfa and Beta mounds. These mounds were found at the NW slope of the Gimini MV at the Pen Duick Mound Province. We analyzed vertical distribution profiles of sulfate, sulfide, chlorinity, DIC in combination with hydrocarbon gas measurements and lipid biomarker study. To have estimates of Sea Surface Temperature (SST) during the carbonate mound formation, we applied the TEX86 (TetraEther indeX of tetraethers with 86 carbon atoms; Schouten et al., 2002) and the alkenone-based UK37 index (Müller et al., 1998). The pore-water data revealed the presence of brine inflow, which is consistent with the data of Hensen et al., (2007). The behavior of sulfide distribution profiles and δ13C values from dissolved inorganic carbon (DIC) indicated that most of the sulfide and DIC are resulted from the microbial anaerobic oxidation of methane (AOM) processes. In contrast, the analysis of archaeal membrane lipids from distinct clades of AOM-mediating anaerobic methanotrophs showed exceedingly low concentrations of specific biomarkers, which is in contradiction with pore-water and gas chemistry data. Besides, AOM is the main cause for the increase of sedimentary alkalinity that leads to carbonate precipitation. Instead, some

  1. Giant polygons and mounds in the lowlands of Mars: signatures of an ancient ocean?

    PubMed

    Oehler, Dorothy Z; Allen, Carlton C

    2012-06-01

    This paper presents the hypothesis that the well-known giant polygons and bright mounds of the martian lowlands may be related to a common process-a process of fluid expulsion that results from burial of fine-grained sediments beneath a body of water. Specifically, we hypothesize that giant polygons and mounds in Chryse and Acidalia Planitiae are analogous to kilometer-scale polygons and mud volcanoes in terrestrial, marine basins and that the co-occurrence of masses of these features in Chryse and Acidalia may be the signature of sedimentary processes in an ancient martian ocean. We base this hypothesis on recent data from both Earth and Mars. On Earth, 3-D seismic data illustrate kilometer-scale polygons that may be analogous to the giant polygons on Mars. The terrestrial polygons form in fine-grained sediments that have been deposited and buried in passive-margin, marine settings. These polygons are thought to result from compaction/dewatering, and they are commonly associated with fluid expulsion features, such as mud volcanoes. On Mars, in Chryse and Acidalia Planitiae, orbital data demonstrate that giant polygons and mounds have overlapping spatial distributions. There, each set of features occurs within a geological setting that is seemingly analogous to that of the terrestrial, kilometer-scale polygons (broad basin of deposition, predicted fine-grained sediments, and lack of significant horizontal stress). Regionally, the martian polygons and mounds both show a correlation to elevation, as if their formation were related to past water levels. Although these observations are based on older data with incomplete coverage, a similar correlation to elevation has been established in one local area studied in detail with newer higher-resolution data. Further mapping with the latest data sets should more clearly elucidate the relationship(s) of the polygons and mounds to elevation over the entire Chryse-Acidalia region and thereby provide more insight into this

  2. Sub-kilometre (intra-crater) mounds in Utopia Planitia, Mars: character, occurrence and possible formation hypotheses

    NASA Astrophysics Data System (ADS)

    Soare, Richard J.; Conway, Susan J.; Pearce, Geoffrey D.; Costard, François; Séjourné, Antoine

    2013-08-01

    At the middle latitudes of Utopia Planitia (˜35-45°N; ˜65-101°E) hundreds of small-sized mounds located in sub-kilometre impact craters dot the landscape. Their shape varies from circular to crescentic and their height ranges from ˜10 to 50 m. Often, metre to decametre pitting is observed, as is metres-thick banding or stratification. Mound albedo is relatively high, i.e. ˜0.16. The plain's terrain in the region, previously linked to the latitude-dependent mantle (LDM) of ice-dust, displays pitting and albedo similar to the small intra-crater mounds. Some workers have suggested that the mounds and the plain's terrain share a common ice-dust origin. If so, then scrutinising the mounds could provide analogical insight on the key geological characteristics and spatial distribution of the LDM itself. Other workers have hypothesised that the mounds are eroded sedimentary landforms or periglacial mounds underlain by a perennial ice-core (closed-system pingos). In this article we develop and then discuss each of the three mound-hypotheses in a much more substantial manner than has been done hitherto. Towards this end we use high-resolution images, present a detailed regional-map of mound distribution and establish a regional platform of topographical analysis using MOLA data superposed on a large-scale CTX mosaic. Although the ice-dust hypothesis is consistent with some observations and measurements, we find that a (loess-based) sedimentary hypothesis shows greater plausibility. Of the three hypotheses evaluated, the pingo or periglacial one is the weakest.

  3. Discovery Of An Extensive Hydrothermal Sulfide/Sulfate Mounds Field In East Diamante Caldera, Mariana Volcanic Arc

    NASA Astrophysics Data System (ADS)

    Hein, J. R.; de Ronde, C. E.; Ditchburn, R.; Leybourne, M. I.; Tamura, Y.; Stern, R. J.; Conrad, T. A.; Nichols, A. R.; Shukuno, H.; Embley, R. W.; Bloomer, S. H.; Ishizuka, O.; Hirahara, Y.; Senda, R.; Nunokawa, A.; Jordan, E.; Wada, I.

    2010-12-01

    An elongate field of hydrothermal mounds was discovered along the NE flank of a cluster of resurgent dacite domes in East Diamante Caldera using the ROV Hyper-Dolphin aboard the R.V. Natsushima in June 2009 and July 2010. East Diamante seamount lies about 80 km north of Saipan and is the northernmost volcano of the Southern Seamount Province of the Mariana magmatic arc. East Diamante is an irregular caldera about 10 km x 4 km that is breached on the north and south sides. The caldera floor has a maximum water depth of about 700 m. After caldera collapse, dacitic domes intruded into the center of the caldera providing the heat source for production and circulation of hydrothermal fluids that generated the large mounds field and two nearby chimney fields, one active and one inactive, found in 2004 during a NOAA Ring-of-Fire cruise. The mounds field is more than 100 m long and about 25-30 m wide and occurs along a NE-SW rift valley at water depths of about 365-400 m b.s.l. Individual hydrothermal mounds and ridges along this trend vary in size and the bases of the mounds are buried beneath hydrothermal sediment so that only minimum dimensions can be determined. Mounds are typically 1-3 m tall and 0.5-2 m wide, with lengths of about 3 to more than 5 m. The sulfide/sulfate mounds are layered and an iron- and manganese-oxide subsidiary mound venting low-temperature fluids caps some of them. Some mounds also support inactive sulfide/sulfate chimneys and spires; chimneys rarely occur as independent structures within the mounds field. The mounds are composed primarily of barite layers and sphalerite (high cadmium, low iron) plus galena layers with up to 470 ppm silver and 3 ppm gold. The subsidiary mounds are composed of 7A manganate and goethite that occur around a delicate network of 2-10 mm diameter anastomosing channels. Similar oxides cover the seabed throughout the mounds field and precipitated from diffuse fluid flow throughout the region, but formed by both diffuse

  4. Tobi sidescan sonar mapping of carbonate mound provinces and channel heads in the Porcupine Seabight, W of Ireland

    NASA Astrophysics Data System (ADS)

    Huvenne, V.; van Rooij, D.; Wheeler, A.; de Haas, H.; Henriet, J. P.

    2003-04-01

    A large-scale sidescan sonar survey, using the 30 kHz TOBI system of the SOC, was carried out in summer 2002 over the carbonate mound provinces of the Porcupine Seabight and Rockall Trough, W of Ireland (EASSS III contract HPRI-CT-1999-00047, survey partly on behalf of the Porcupine Studies Group). The survey in the Porcupine Seabight focused on the Hovland-Magellan province in the north and the Belgica province on the eastern flank of the basin. Furthermore a reconnaissance track was added over the canyon heads of the Gollum Channel System further south in the Seabight. Each area has different characteristics. The Hovland-Magellan province shows a very homogeneous backscatter in the sidescan mosaics, indicating a quiet depositional environment. Mounds appear as sharp features with a strong backscatter and an acoustic shadow. Some Hovland mounds form multiple, ridge-like structures of more than a km in length. The Magellan mounds are nearly all buried, but leave subtle topographic effects at the seafloor. The Belgica mound province is characterised by much less homogeneous backscatter and a steeper seafloor slope. The mounds are placed en echelon along the slope and are bound to the W by a blind channel. Smaller down-slope channels are also found between the mounds. Many small, high-backscatter features, interpreted as incipient ('Moira') mounds have been found in this province. Striations in the blind channel, and higher up on the slope of the Belgica province indicate the influence of high current speeds. Pockmarks have been found just south of the Belgica province. The Gollum Channels are steep-flanked, U- or V-shaped channels of ca. 200 m deep. Their steep walls are cut by gullies and feeder channels, and evidence of slope failures is present. Lineations and high-backscatter patches are found on some of the channel floors.

  5. Association among active seafloor deformation, mound formation, and gas hydrate growth and accumulation within the seafloor of the Santa Monica Basin, offshore California

    USGS Publications Warehouse

    Paull, C.K.; Normark, W.R.; Ussler, W., III; Caress, D.W.; Keaten, R.

    2008-01-01

    Seafloor blister-like mounds, methane migration and gas hydrate formation were investigated through detailed seafloor surveys in Santa Monica Basin, offshore of Los Angeles, California. Two distinct deep-water (??? 800??m water depth) topographic mounds were surveyed using an autonomous underwater vehicle (carrying a multibeam sonar and a chirp sub-bottom profiler) and one of these was explored with the remotely operated vehicle Tiburon. The mounds are > 10??m high and > 100??m wide dome-shaped bathymetric features. These mounds protrude from crests of broad anticlines (~ 20??m high and 1 to 3??km long) formed within latest Quaternary-aged seafloor sediment associated with compression between lateral offsets in regional faults. No allochthonous sediments were observed on the mounds, except slumped material off the steep slopes of the mounds. Continuous streams of methane gas bubbles emanate from the crest of the northeastern mound, and extensive methane-derived authigenic carbonate pavements and chemosynthetic communities mantle the mound surface. The large local vertical displacements needed to produce these mounds suggests a corresponding net mass accumulation has occurred within the immediate subsurface. Formation and accumulation of pure gas hydrate lenses in the subsurface is proposed as a mechanism to blister the seafloor and form these mounds. ?? 2008 Elsevier B.V. All rights reserved.

  6. Corrosion of copper in Mound's single-pass potable water systems

    SciTech Connect

    Schleitweiler, P.M.; Miller, P.S.

    1990-12-07

    An increase in the number of copper plumbing failures at Mound prompted a thorough analysis of the failed components. Most of the components were elbow joints. All of these parts exhibited the same type of accelerated deterioration. The failed parts were analyzed optically and by scanning electron microscopy. Water chemistry, solder, and soldering fluxes were evaluated to determine their possible roles in the accelerated attack. Cross-sectioning of the elbow joints revealed residual soldering flux and cutting burrs on the inside of the elbows. Water analysis showed Mound's water was rated as corrosive. Recommendations for improved workmanship and design are presented. Testing of potable water at a regular basis was also recommended. 8 refs., 10 figs., 3 tabs.

  7. Sources of Sulfate Found in Mounds and Lakes at the Lewis Cliffs Ice Tongue, Transantarctic

    NASA Technical Reports Server (NTRS)

    Socki, Richard; Sun, Tao; Harvey, Ralph P.; Bish, David L.; Tonui, Eric; Bao, Huiming; Niles, Paul B.

    2012-01-01

    Massive but highly localized Na-sulfate mounds (mirabilite, Na2SO4.10H2O) have been found at the terminal moraine of the Lewis Cliffs Ice Tongue (LCIT), Antarctica. (Sigma)34S and (Sigma)18O values of LCIT mirabilite range from +48.8 to +49.3% (CDT), and -16.6 to -17.1% (V-SMOW), respectively, while (Delta)17O average -0.37% (V-SMOW). LCIT mirabilite mounds are isotopically different from other mirabilite mounds found in coastal regions of Antarctica, which have isotope values close to seawater compositions. (Sigma)18O and (Delta)17O values suggest the incorporation of isotopically light glacial water. Data point to initial sulfate formation in an anoxic water body, either as a stratified anoxic deep lake on the surface, a sub-glacial water reservoir, or a sub-glacial lake. Several surface lakes of varying size are also present within this region of the LCIT, and in some cases are adjacent to the mirabilite mounds. O and D isotope compositions of surface lakes confirm they are derived from a mixture of glacial ice and snow that underwent moderate evaporation. (Sigma)18O and (Sigma)D (V-SMOW) values of snow, ice, and lake water range from -64.2 to -29.7%, and -456.0 to -231.7%, respectively. However, the isotope chemistry of these surface lakes is extremely different from the mounds. Dissolved SO4-2 (Sigma)34S and (Sigma)18O values range from +12.0 to +20.0% and -12.8 to -22.2% (the most negative (Sigma)18O of terrestrial sulfate ever reported), respectively, with sulfate (Delta)17O ranging from +0.93 to 2.24%. Ion chromatography data show that lake water is fresh to brackish in origin, with TDS less than 1500 ppm, and sulfate concentration less than 431 ppm. Isotope and chemical data suggest that these lakes are unlikely the source of the mirabilite mounds. We suggest that lake water sulfate is potentially composed of a mixture of atmospheric sulfate and minor components of sulfate of weathering origin, much like the sulfate in the polar plateau soils of the Mc

  8. Genesis and fluid source in Arabia crater mounds: mapping, fractal analysis, and impact simulations

    NASA Astrophysics Data System (ADS)

    Pozzobon, R.; Mazzarini, F.; Rossi, A.; Lucchetti, A.; Pondrelli, M.; Marinangeli, L.; Martellato, E.; Cremonese, G.; Massironi, M.

    2013-12-01

    Arabia Terra is dominated by heavily cratered terrains, and some peculiar landforms can be found mostly in craters interior. With high-resolution images from HiRISE (25 cm/px) and CTX (6 m/px) cameras pitted cones, mounds and knobs can be easily recognized. Those mounds are interpreted to have worked as pathways for subsurface fluid. It is commonly hypothesized that Arabia Terra is an area of past fluid activity, being crater central bulges a place of sulfate precipitation. In this work we investigate the presence, origin and timing of their formation as well as the the depth of the mounds fluid source. The spatial distribution of monogenic eruptive structures within volcanic areas on Earth has been linked to fracture systems that allowed an efficient hydraulic connection between surface and crustal or subcrustal magma reservoirs. Self-similarity in vent distribution is described by a power law distribution with fractal exponent D and defined over a range of lengths comprised between a lower limit (lower cutoff, Lco) and an upper limit (upper cutoff, Uco). On Earth, volcanic vents as well as mud volcanoes have shown that the Uco of their fractal distribution scales with the depth of pressurized fluid reservoirs. The same approach has been this applied to mounds mapped at Firsoff and Crommelin craters. 431 mounds were mapped on Firsoff Crater's floor, and 160 on Crommelin Crater's floor. The reslulting Uco for both craters are similar giving a source depth of 2.3 ×0.3 km from Firsoff Crater's ground floor and 2.6 ×0.5 km from Crommelin's floor. Hence it is possible to hypothesize a common regional-scale pressurized fluid level at 2.5 km of depth from craters floor. Morphogic and stratigraphical analyses of the high-resolution imagery and topography of those mounds allowed us to discern from actual mud volcano candidates and stratigraphic erosional remnants. We also studied the craters formation by simulating the impact with the hydrocode. We used iSALE shock code

  9. Geometry-Lithology-Origin: Solving the mystery of the Late Miocene mounded features below Lake Balaton

    NASA Astrophysics Data System (ADS)

    Visnovitz, Ferenc; Horváth, Ferenc; Surányi, Gergely

    2014-05-01

    The Department of Geophysics and Space Sciences of Eötvös University has carried out single- and multichannel water seismic surveys at the Lake Balaton since 1993. The dense grid of 2D profiles offers a high resolution image of the Late Miocene sedimentary strata (Tihany, Somló and Szák Formations) up to a thickness of 200 meters below the lake. These strata can be divided into smaller sedimentary units by numerous parasequence boundaries (Sztanó&Magyar, 2007). In one of these parasequence interesting, high amplitude mounded features have been observed that follow a seismic horizon over large area. It means that these features indicate a Late Miocene regional event. In terms of their shape these mounds are few tens of meters wide, several tens to a hundreds of meters long and few meters high. Their geometry and inner structure were mapped from 2D segments that were used for 3D reconstructions. The shape and stratigraphic position of these features have inspired Sacchi and Horvath (1999) to interpret them as the subsurface equivalent of the fresh-water siliceous-limestone mounds exposed on the Tihany Peninsula. They held these mounds as an evidence of dryland conditions in the time period of the formation of a Late Miocene erosional surface (PAN-2) that they regarded as a 3rd order sequence boundary. In addition to this so called "travertine" concept another explanation was also formulated as the mounds are the product of sedimentary failures e.g. slumps or water escape. To solve the problem an offshore drilling with a total depth of 19 meters was accomplished in October 2013 to sample one of these mounds and determine their origin. The well has not crossed any travertine body, instead alternating layers of clay-silt and very fine sand - without any convincing sign of fluid escape structures - were found in the core (typical lithology of the Tihany Formation). 3D structural analysis of the mounds revealed spherical organization composing bodies that are

  10. Methane fluxes from the mound-building termite species of North Australian savannas

    NASA Astrophysics Data System (ADS)

    Jamali, H.; Livesely, S. J.; Arndt, S. K.; Dawes-Gromadzki, T.; Cook, G. D.; Hutley, L.

    2009-04-01

    Termites are estimated to contribute 3-19% to the global methane emissions. These estimates have large uncertainties because of the limited number of field-based studies and species studied, as well as issues of diel and seasonal variation. We measured methane fluxes from four common mound-building termite species (Microcerotermes nervosus, n=26; M. serratus, n=4; Tumulitermes pastinator, n=5; and Amitermes darwini, n=4) in tropical savannas near Darwin in the Northern Territory, Australia. Methane fluxes from replicated termite mounds were measured in the field using manual chambers with fluxes reported on a mound volume basis. Methane flux was measured in both wet and dry seasons and diel variation was investigated by measuring methane flux every 4 hours over a 24 hour period. Mound temperature was measured concurrently with flux to examine this relationship. In addition, five M. nervosus mounds removed from the field and incubated under controlled temperature conditions over a 24 hour period to remove the effect of varying temperature. During the observation campaigns, mean monthly minimum and maximum temperatures for February (wet season) were 24.7 and 30.8°C, respectively, and were 20.1 to 31.4 °C in June (dry season). Annual rainfall in 2008 for Darwin was 1970.1 mm, with a maximum of 670 mm falling in February and no rain in May and June. Methane fluxes were greatest in the wet season for all species, ranging from 265.1±101.1 (T. pastinator) to 2256.6±757.1 (M. serratus) µg CH4-C/m3/h. In the dry season, methane fluxes were at their lowest, ranging from 10.0±5.5 (T. pastinator) to 338.0±165.9 (M. serratus) µg CH4-C/m3/h. On a diel basis, methane fluxes were smallest at the coolest time of the day (~0700 hrs) and greatest at the warmest (~1400 hrs) for all species, and for both wet and dry seasons. Typical diel variation in flux from M. serratus dominated mounds ranged from 902.6±261.9 to 1392.1±408.1 µg CH4-C/m3/h in wet season and 99.6±57.4 to

  11. Organic matter quality and supply to deep-water coral/mound systems of the NW European Continental Margin

    NASA Astrophysics Data System (ADS)

    Kiriakoulakis, K.; Freiwald, A.; Fisher, E.; Wolff, G. A.

    2007-02-01

    Comparison of five deep-water coral (DWC)/mound ecosystems along the European Continental Margin shows that suspended particulate organic matter (sPOM), a potential food source, is lipid rich and of high quality. However, there are differences between the sites. The Darwin and Pelagia Mounds (N. Rockall Trough and N. Porcupine Bank, respectively) have higher proportions of labile particulate lipids (including high proportions of polyunsaturated fatty acids) in the benthic boundary layer than Logachev, Hovland and Belgica Mounds (Rockall Bank, S. Porcupine Bank and Porcupine Seabight, respectively). The high quality sPOM could be transported downslope from the euphotic zone. There is some evidence for inter-annual variability at some sites (e.g. Hovland and Logachev Mounds) as large differences in suspended lipid and particulate organic carbon concentrations were observed over the sampling period. Elevated total organic carbon contents of sediments at mound sites, relative to control sites in some cases (particularly Darwin Mounds), probably reflect local hydrodynamic control and the trapping of sPOM by the DWC. Fresh POM can be relatively rapidly transferred to significant depth (up to 8 cm) through bioturbation that is evident at all sites. There is no clear evidence of present day hydrocarbon seepage at any of the sites.

  12. Do Epigeal Termite Mounds Increase the Diversity of Plant Habitats in a Tropical Rain Forest in Peninsular Malaysia?

    PubMed Central

    Beaudrot, Lydia; Du, Yanjun; Rahman Kassim, Abdul; Rejmánek, Marcel; Harrison, Rhett D.

    2011-01-01

    The extent to which environmental heterogeneity can account for tree species coexistence in diverse ecosystems, such as tropical rainforests, is hotly debated, although the importance of spatial variability in contributing to species co-existence is well recognized. Termites contribute to the micro-topographical and nutrient spatial heterogeneity of tropical forests. We therefore investigated whether epigeal termite mounds could contribute to the coexistence of plant species within a 50 ha plot at Pasoh Forest Reserve, Malaysia. Overall, stem density was significantly higher on mounds than in their immediate surroundings, but tree species diversity was significantly lower. Canonical correspondence analysis showed that location on or off mounds significantly influenced species distribution when stems were characterized by basal area. Like studies of termite mounds in other ecosystems, our results suggest that epigeal termite mounds provide a specific microhabitat for the enhanced growth and survival of certain species in these species-rich tropical forests. However, the extent to which epigeal termite mounds facilitate species coexistence warrants further investigation. PMID:21625558

  13. Autonomous underwater vehicle (AUV) mapping reveals coral mound distribution, morphology, and oceanography in deep water of the Straits of Florida

    NASA Astrophysics Data System (ADS)

    Grasmueck, Mark; Eberli, Gregor P.; Viggiano, David A.; Correa, Thiago; Rathwell, Glenda; Luo, Jiangang

    2006-12-01

    To make progress in understanding the distribution and genesis of coral mounds in cold and dark water, maps of morphology and oceanographic conditions resolving features at the 1-10 m scale are needed. An autonomous underwater vehicle (AUV) cruising 40 m above the seafloor surveyed a 48 km2 coral mound field in 600-800 m water depth at the base of slope of Great Bahama Bank. The AUV acquired 1-3 meter resolution acoustic backscatter and bathymetry together with current vectors, salinity, and temperature. The multibeam bathymetry resolved more than 200 coral mounds reaching up to 90 m height. Mound morphology is surprisingly diverse and mound distribution follows E-W oriented off-bank ridges. Bottom currents reverse every 6 hours indicating tidal flow decoupled from the north flowing surface current. The AUV data fill the gap between low-resolution surface-based mapping and visual observations on the seafloor, revealing the dynamic environment and spatial relationships of an entire coral mound field.

  14. Dickinson field lodgepole reservoir: Significance of this Waulsortian-type mound to exploration in the Williston Basin

    SciTech Connect

    Johnson, M.S.

    1995-07-01

    Conoco`s No. 74 Dickinson State well, a deep test in Dickinson Field, Stark County, North Dakota, was completed in early 1993 capable of producing over 2,000 BOPD. It represents the first commercial oil production from the Lower Mississippian Lodgepole Formation in the U.S. portion of the Williston Basin. Three additional oil producers have now been completed and this Lodgepole discovery is fully developed. The producing reservoir, at depths of 9,700 to 10,000 ft, is a Waulsortian-type mound approximately 300 ft thick with a characteristic faunal assemblage of bryozoans and crinoids. The mound has an areal extent of slightly more than 1 square mile. Similar Waulsortian-type mounds have been recognized in rocks of Paleozoic age around the world, but have only been reported in the Williston Basin during the past decade. Such mounds are shallow to deep water deposits, tend to develop over structurally or topographically-positive areas, and may form by algal or by current action in conjunction with baffling action caused by bryozoans. The prolific nature of the Conoco discovery, plus several more-recent excellent mound discoveries in this same area, have caused renewed drilling and leasing activity. These events have also encouraged a review of existing seismic data, the shooting of new 3-D seismic programs and re-analysis of wells previously drilled through the Lodgepole Formation for evidence of similar mounds elsewhere in the basin.

  15. Macrofauna community inside and outside of the Darwin Mounds SAC, NE Atlantic

    NASA Astrophysics Data System (ADS)

    Serpetti, N.; Gontikaki, E.; Narayanaswamy, B. E.; Witte, U.

    2012-11-01

    Over the past two decades, growing concerns have been raised regarding the effects of towed fishing gears, such as trawls and dredges, on deep-sea biodiversity and ecosystem functioning. Trawling disturbs the benthic communities both physically and biologically, and can eliminate the most vulnerable organisms and modify habitat structure; chronically disturbed communities are often dominated by opportunistic species. The European Union is under obligation to designate a network of offshore Special Areas of Conservation (SACs) and Marine Protected Areas (MPAs) by the end of 2012 based on the perceived expectation that these networks will help protect marine biodiversity and that within these areas, faunal abundance and diversity will be higher than the surrounding fished areas. The Darwin Mounds, only discovered in 1998, are located in the Rockall Trough, NE Atlantic at a depth of ~ 1000 m. Deep-water trawling regularly took place in the region of the Darwin Mounds; however in 2004 the mounds were designated as the first offshore SAC in UK and the area is now closed to bottom trawling. As part of the HERMIONE programme the influence of human impact on the Oceans was one of the key themes and in June 2011, an investigation of the macrofaunal community structure at comparable sites both inside and outside of the Darwin Mound SAC was undertaken. Macrofaunal communities were found to differ significantly, with the difference mostly driven by changes in the abundance of polychaetes, crustaceans and nematodes whilst no significant differences were seen for the other phyla. Whereas overall macrofaunal abundance was higher outside the SAC compared to within, this pattern varies considerably between phyla. Diversity indices showed no significant differences between protected and unprotected sites. This could indicate that a few years of preservation are not enough time to determine a recovery by the macrofaunal community of cold-water ecosystems and that a continued

  16. Mineralogy, chemical composition and structure of the MIR Mound, TAG Hydrothermal Field

    NASA Astrophysics Data System (ADS)

    Stepanova, T. V.; Krasnov, S. G.; Cherkashev, G. A.

    The study of samples collected from the surface of the MIR mound (TAG Hydrothermal Field) by video-controlled hydraulic grab allowed identification of a number of mineralogical types. These include pyrite-chalcopyrite (Py-Cp), bornite-chalcopyrite-opaline (Bn-Cp-Op) and sphalerite-opaline (Sp-Op) sulfide chimneys, massive sulfides composed of pyrite (Py), chalcopyrite-pyrite (Cp-Py), marcasite-pyrite-opaline (Mc-Py-Op), sphalerite-pyrite-opaline (Sp-Py-Op) and sphalerite-chalcopyrite-pyrite-opaline (Sp-Cp-Py-Op), as well as siliceous and Fe-Mn oxide hydrothermal deposits. Most of the minor elements (Ag, Au, Cd, Ga, Hg, Sb and Pb) are associated with Zn-rich massive sulfides, Co Bi, Pb, and As with Ferich ones, while Cu-rich sulfides are depleted of trace metals. Cu-enriched assemblages are concentrated in the northern part, Zn-enriched in the center, and siliceous rocks in the south of the MIR mound. According to paragenetic relations, the development of the mound started with the formation of quartz (originally opaline) rocks and dendritic assemblages of melnikovite-pyrite, followed by deposition of chalcopyrite and recrystallization of primary pyrite, subsequent generation of sphalerite-rich assemblages and final deposition of opaline rocks. The late renewal of hydrothermal activity led to local formation of Cu-rich chimneys enriched in Au, Ag, Hg and Pb probably due to their remobilization from inner parts of the deposit.

  17. Chemistry and mineralogy of samples from the strategic petroleum reserve Bryan Mound site

    SciTech Connect

    Bild, R. W.

    1980-08-01

    The goal of the Strategic Petroleum Reserve (SPR) program is to protect the United States from a temporary cutoff of imported crude oil by stockpiling a reserve of oil in caverns in Gulf Coast salt domes. Some suitable caverns already exist as a result of solution mining activities by commercial mining companies. Most of the caverns for the program, however, will be solution mined specifically for the SPR program. The tasks assigned to Sandia National Laboratories include conducting a geotechnical program and providing interim technical support for the leaching of the first five caverns in the Bryan Mound, Texas, salt dome. This report describes chemical, mineralogical and petrological work done at Sandia as of May 1, 1980 in support of Bryan Mound activities. Samples of Bryan Mound salt cores, sidewall samples and drill cuttings have been subjected to chemical, mineralogical and petrographic analysis. Halite (NaCl) was the major mineral in all samples with anhydrite (CaSO/sub 4/) a common accessory. Minor or trace sylvite (KCl) and quartz (SiO/sub 2/) were detected in some sidewall samples. Other minor minerals found in drill cuttings included quartz; mixed carbonates of Fe, Ca and Mg; and several iron oxides. Possibly the carbonates are reaction products with the basic drilling mud or possibly pieces of caprock which contaminated the cuttings. The iron oxides were probably produced by corrosion of the drill stem or bit. Densities of several core samples were determined and insoluble residue was counted for radioactivity.

  18. Pre-operational safety appraisal Tritiated Scrap Recovery Facility, Mound facility

    SciTech Connect

    Dauby, J.J.; Flanagan, T.M.; Metcalf, L.W.; Rhinehammer, T.B.

    1996-07-01

    The purpose of this report is to identify, assess, and document the hazards which are associated with the proposed operation of the Tritiated Scrap Recovery Facility at Mound Facility. A Pre-operational Safety Appraisal is a requirement as stated in Department of Energy Order 5481.1, Safety Analysis and Review System. The operations to be conducted in the new Tritiated Scrap Waste Recovery Facility are not new, but a continuation of a prime mission of Mound`s i.e. recovery of tritium from waste produced throughout the DOE complex. The new facility is a replacement of an existing process started in the early 1960`s and incorporates numerous design changes to enhance personnel and environmental safety. This report also documents the safety of a one time operation involving the recovery of tritium from material obtained by the Department of Energy from the State of Arizona. This project will involve the processing of 240,000 curies of tritium contained in glass ampoules that were to be used in items such as luminous dial watches. These were manufactured by the now defunct American Atomics Corporation, Tucson, Arizona.

  19. Pleistocene periglacial cryogenic mounds (lithalsas) on basalt plateaus in the western Pannonian Basin

    NASA Astrophysics Data System (ADS)

    Sebe, Krisztina; Csillag, Gábor

    2015-04-01

    On some basalt plateaus of the western Pannonian Basin, Hungary, fields of circular depressions occur. They are traditionally called "basalt karst' and their formation has been attributed either to collapse over karstifying rocks or to anthropogenic action (quarrying); however, both of these theories are questionable. The depressions are situated between elevations of 350-500 m a.s.l. and are characteristically surrounded by circular raised rims or ramparts. They measure a few m-s (up to ~10 m) in diameter, the ramparts emerge 0.5-1.5 m above the surrounding level ground and encircle a depression of 1-2 (-3) m deep in the middle. Depressions cluster in well delineated, high-density groups, with individual fields containing several dozens of these forms. Neighbouring ramparts are tightly packed, often interfere and depressions can thus coalesce creating composite forms. The ramparts are composed of coarse (dm-sized) basalt blocks, whose material is identical to that of the surrounding terrain and seems to originate from the depression. Many of the depressions host ephemeral ponds. Raised rims exclude formation of these landforms by any karstic processes. The anthropogenic theory is opposed by the lack of the remains of any facilities (e.g. roads), of tools and by the very illogical distribution and geometry of depressions from the point of human use. On the contrary, we interpret these ramparted depressions as being of periglacial origin, remnants of cryogenic mounds. The central depression and the emergent rampart can be well explained by the ice core raising the overlying rock and by the radial downsliding of this material on the ice core to the margins. Within cryogenic mounds, clustering and size of the forms fits the characteristics of perennial frost mound without peat cover, i.e. lithalsas or minerogenic palsas. Cryogenic mounds are important paleoclimatic indicators. Based on modern analogs, these lithalsa scars indicate the former presence of discontinuous

  20. Amplitude vs. Offset Effects on Gas Hydrates at Woolsey Mound, Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Anderson, Walter R., Jr.

    Due to the estimated massive quantities of natural methane hydrates, they represent one of the largest sources of future alternative energy on Earth. Methane hydrates have been found in the shallow sub-seafloor of the Northern Gulf of Mexico where the water depth is in excess of ~900 m. Mississippi Canyon Block 118 has been chosen by the Gulf of Mexico Hydrates Research Consortium to be the site of a multi-sensor, multi-discipline sea-floor observatory for gas hydrate research. First evidence for gas hydrates at MC 118 was observed at Woolsey Mound. Subsurface evidence for gas hydrates has subsequently been substantiated by 3D seismic reflection data and piston coring. It is estimated that methane trapped within gas hydrates worldwide may exceed 1016 kg, one of the largest sources of hydrocarbons to date, and here they present an opportunity for exploitation via harvesting for energy production. The analysis of the 3-D seismic reflection data and integration with industry well logs reveals the subsurface structural and stratigraphic architecture of a thermogenic hydrate system in the Mississippi Canyon area (MC-118) of the Gulf of Mexico. Like many hydrocarbon systems in the Gulf of Mexico, Woolsey Mound is dominated by the presence and sporadic movement of allochthonous salt within the sedimentary section. Exploration-scale 3-D seismic imaging shows a network of faults connecting the mound to a salt diapir and an extended area of high P-wave velocity just beneath the sea floor. Gas hydrates exhibit clear seismic properties such as the bottom simulating reflector (BSR), relatively high P- and S- wave velocities, seismic blanking, and amplitude vs. offset (AVO) effects. These effects occur mainly due to the presence of free gas that is usually trapped by the more rigid overlying hydrate formations. In order to substantiate the presence of hydrates in the shallow subsurface at Woolsey Mound, an AVO analysis based on the variation of the P-wave reflection coefficient

  1. Carbonate mound evolution and coral diagenesis viewed by U-series dating of deep water corals

    NASA Astrophysics Data System (ADS)

    Frank, N.; Ricard, E.; Blamart, D.; van der Land, C.; Colin, C.; Foubert, A.; van Rooij, D.; van Weering, T.

    2007-12-01

    U-series dating of constructional deep sea corals is a powerful tool to reconstruct the evolution of carbonate mound sediments driven by coral growth, sediment trapping and diagenesis. Here we have investigated in great detail the time framework of constructional corals such as L. pertusa and M. oculata on 5 different mounds of the eastern North Atlantic (on Rockall Bank and in Porcupine Seabight) taken at variable depth and location (610 to 880m water depth). Periods favorable for coral growth are the Holocene and prior interglacials such as marine isotope stage 5 and 7, while glacial coral growth seems inhibited or extremely reduced. Coral development is almost continuous throughout the Holocene since mound re-colonization about 10,500 years ago. Mound accumulation rates vary between 20 and 220 cm/kyr determined from the coral age - depth relationship in each core. Those changes are most likely driven by changes between horizontal and vertical mound accumulation, food supply and ocean circulation. In addition, coral dating allowed to identify an important erosional event recorded in core MD01-2455G from Rockall Bank. Here a 1m thick sediment layer containing ancient corals likely from the start of Holocene re-colonization was displaced (collapsed) from further upslope on top of younger corals of ~2500 to 3000 years age. Prior to the initiation of coral growth diagenesis occurred frequently resulting in (1) the construction of so called carbonate hardgrounds and/or (2) the dissolution of the pre-Holocene coral framework. Solely, the deepest selected core in Porcupine Seabight (MD01-2463G at 880m depth) reveals coral re-colonization on an undisturbed ancient reef structure that dates back to 250,000 years. Diagenesis of earlier coral reef generations leading to coral dissolution leads to a loss of magnetic susceptibility and open system behavior of the coral skeletons with respect to U-series dating. While the processes causing such diagenetic layers are barely

  2. Grainstones and cementstone mounds: The Trogkofel summit section (Lower Permian, Carnic Alps, Austria).

    NASA Astrophysics Data System (ADS)

    Schaffhauser, M.; Sanders, D.; Krainer, K.

    2009-04-01

    In the Carnic Alps, Austria, an Artinskian succession 400 m thick of shallow-water bioclastic limestones and of mounds composed of ?Archaeolithophyllum, Archaeolithoporella and abundant fibrous cementstone (after former aragonite) records deposition along a "grainstone-dominated" platform margin. The section was taken along the route through the east-facing cliff of Trogkofel. The Trogkofel Limestone (Artinskian pro parte) is excellently exposed and preserved the most complete along this route, but no section has hitherto been logged. The total thickness of the Trogkofel Limestone probably is about 550 meters; the summit section comprises its upper 400 meters. The section consists mainly of shallow-water bioclastic limestones (grainstones, packstones, rudstones) intercalated with cementstone mounds. Both the bioclastic limestones and the mounds typically are thick-bedded to, more commonly, unbedded. Throughout the section, intervals a few tens of meters in thickness dominated by bioclastic limestones change vertically with intervals dominated by cementstone mounds. Up-section, no clear-cut trend with respect to prevalent facies, mean depositional water depth, and energy index is obvious. Furthermore, no lime-muddy, meter-scale peritidal cycles, and no teepee structures and no pisolite levels were identified; thin intervals of fenestral lime mudstones and/or of cryptmicrobially-laminated limestones are very rare. The bioclastic limestones commonly weather out unstratified, or show subhorizontal stratification or, more rarely, low-angle cross-stratification. In the upper 100 meters of section, grainstones to fine-grained rudstones rich in keystone vugs are prevalent. The cementstone mounds comprise intervals up to a few meters in thickness; the biogenic component is characterized by foliose crusts pertaining to ?Archaeolithophyllum hidensis and Archaeolithoporella, overgrown by Tubiphytes and fenestrate bryozoans. The ?Archaeolithophyllum-Archaeolithoporella crusts

  3. POTENTIAL IMPACT OF BLENDING RESIDUAL SOLIDS FROM TANKS 18/19 MOUNDS WITH TANK 7 OPERATIONS

    SciTech Connect

    Eibling, R; Erich Hansen, E; Bradley Pickenheim, B

    2007-03-29

    High level waste tanks 18F and 19F have residual mounds of waste which may require removal before the tanks can be closed. Conventional slurry pump technology, previously used for waste removal and tank cleaning, has been incapable of removing theses mounds from tanks 18F and 19F. A mechanical cleaning method has been identified that is potentially capable of removing and transferring the mound material to tank 7F for incorporation in a sludge batch for eventual disposal in high level waste glass by the Defense Waste Processing Facility. The Savannah River National Laboratory has been requested to evaluate whether the material transferred from tanks 18F/19F by the mechanical cleaning technology can later be suspended in Tank 7F by conventional slurry pumps after mixing with high level waste sludge. The proposed mechanical cleaning process for removing the waste mounds from tanks 18 and 19 may utilize a high pressure water jet-eductor that creates a vacuum to mobilize solids. The high pressure jet is also used to transport the suspended solids. The jet-eductor system will be mounted on a mechanical crawler for movement around the bottom of tanks 18 and 19. Based on physical chemical property testing of the jet-eductor system processed IE-95 zeolite and size-reduced IE-95 zeolite, the following conclusions were made: (1) The jet-eductor system processed zeolite has a mean and median particle size (volume basis) of 115.4 and 43.3 microns in water. Preferential settling of these large particles is likely. (2) The jet-eductor system processed zeolite rapidly generates settled solid yield stresses in excess of 11,000 Pascals in caustic supernates and will not be easily retrieved from Tank 7 with the existing slurry pump technology. (3) Settled size-reduced IE-95 zeolite (less than 38 microns) in caustic supernate does not generate yield stresses in excess of 600 Pascals in less than 30 days. (4) Preferential settling of size-reduced zeolite is a function of the amount of

  4. Study of resonant modes of the harbour of Siracusa, Italy, and of the effects of breakwaters in case of a tsunami event.

    NASA Astrophysics Data System (ADS)

    Pagnoni, Gianluca; Tinti, Stefano

    2016-04-01

    The eastern coast of Sicily has been hit by many historical tsunamis of local and remote origin. This zone and in particular Siracusa, as test site, was selected in the FP7 European project ASTARTE (Assessment, Strategy And Risk Reduction for Tsunamis in Europe - FP7-ENV2013 6.4-3, Grant 603839). According to the project goals, in this work oscillations modes of the Siracusa harbour were analysed with focus on the typical tsunami periods range, and on the protecting effects of breakwaters by using linear and non-linear simulation models. The city of Siracusa is located north of the homonymous gulf and has two harbours, called "Piccolo" (small) and "Grande" (grand) that are connected through a narrow channel. The harbour "Piccolo" is the object of this work. It is located at the end of a bay facing east and bordered on the south by the peninsula of Ortigia and on the north by the mainland. The basin has an area of approximately 100,000 m2 and is very shallow with an average depth of 2.5 m. It is protected by two breakwaters reducing its mouth to only 40 m width. This study was carried out using the numerical code UBO-TSUFD that solves linear and non-linear shallow-water equations on a high-resolution 2m x 2m regular grid. Resonant modes were searched by sinusoidal forcing on the open boundary with periods in a range from about 60 s to 1600 s covering the typical tsunami spectrum. The work was divided into three phases. First we studied the natural resonance frequencies, and in particular the Helmholtz resonance mode by using a linear fixed-geometry model and assuming that the connecting channel between the two Siracusa ports is closed. Second, we repeated the analysis by using a non-linear simulation model accounting for flooding and for an open connection channel. Eventually, we forced the harbour by means of synthetic signals with amplitude, period and duration of the main historical tsunamis attacking Siracusa, namely the AD 365, the 1693 and the 1908 tsunami

  5. Geoarchaeological approaches to understanding human-environment interactions in Australia's tropical north: the Weipa shell mounds revisited.

    NASA Astrophysics Data System (ADS)

    Fanning, P. C.; Holdaway, S. J.; Shiner, J.; Petchey, F.

    2012-04-01

    Western Cape York Peninsula, particularly the Weipa region, has seen sustained archaeological investigation since the 1960s. These studies primarily concentrated on the shell mounds associated with coastal environments first observed at the beginning of the 20th century. Despite claims that the shell mounds were of natural origin, archaeological investigations convincingly demonstrated that they are primarily cultural deposits. Geomorphological studies indicate that chenier (beach ridge) formation occurred after sea-level stabilisation in the mid- to late Holocene, and is connected to the formation of estuaries at the mouths of the Mission, Pine, Hey and Embley Rivers. Anadara shell bed formation is in turn connected with the evolution of the estuaries. However, the relationship between shell mound age and location relative to the coastline at Weipa is neither well defined, nor tested at multiple locations. Given that the coast is susceptible to the effects of sea-level fluctuations and environmental change, and the Anadara beds can become depleted as a result of environmental shifts, the shell mounds provide a datable record of human reaction to coastal landscape and environmental change. Here, we report preliminary results of a new investigation of the shell mounds of the Weipa region. Radiocarbon and OSL-based age determinations from samples of shell, charcoal and sediment collected from trenches excavated into shell mounds on the northern shore of the Embley River indicate a relationship between the time of initial accumulation of shell and the age of the landform features upon which they were built, which in turn are a result of coastline evolution during the mid to late Holocene. These mounds are the oldest yet recorded for the Weipa region, with accumulation in one case commencing around 3500 cal BP. Accumulation appears to be more or less continuous, and abruptly ceases after 400-650 yrs. We discuss implications for understanding human

  6. Heat transfer through the sediments of the Mounds Hydrothermal Area, Galapagos Spreading Center at 86°W

    NASA Astrophysics Data System (ADS)

    Becker, Keir; von Herzen, Richard P.

    1983-01-01

    Heat transfer processes at the mounds area of the Galapagos Spreading Center at 86°W are revealed by temperatures measured at ≈ 10-m intervals in the 30±10m sediment at each of 12 holes at DSDP Leg 70 Sites 506-509 and by temperatures of up to five thermistors on eleven 8-12 m long piston cores. The 325 needle-probe values show a significant linear increase of thermal conductivity with depth in each core. About half of the temperature-thermal resistance profiles are nonlinear and are fit to a steady state, vertical pore water advection model. Results indicate high and variable total heat flow and localized hydrothermal discharge at ≈ 10-8 m/s, associated with individual mounds. Recharge is indicated at similar rates in the low heat flow belt ≈ 5 km south of the mounds and is suggested at slower rates in the intermediate heat flow (0.17-0.42 W/m2) belt surrounding the mounds heat flow high. Possible slow entrained recharge within ≈ 100 m of discharging mounds is suggested. Also suggested is strong local discharge along the major fault bounding the mounds crustal block to the north. About 95 km north of the spreading axis, at DSDP Site 510, temperatures in the 114-m sediment cover on 2.7-m.y. crust are linear, consistent with the suggestion that the hydraulic resistance of this layer is sufficient to seal off free hydrothermal exchange between basement and bottom water. The combination of heat flow data and the physical properties data of Karato and Becker (this issue) suggests that ≈ 50 m of sediment may be a threshold thickness for sealing of hydrothermal circulation within basement, where the topography is smooth. We suggest that the formation of mounds may be associated with the forced localization of hydrothermal discharge through the sediment, as its thickness approaches this threshold value.

  7. A New Approach to Testing the Fossorial Rodent Hypothesis of Mima Mound Formation Using Airborne-Based LIDAR and a Diffusive Sediment Transport Model

    NASA Astrophysics Data System (ADS)

    Reed, S. E.; Amundson, R.

    2007-12-01

    Mima mounds are nearly circular soil mounds, found in grassland landscapes. In California, Mima mounds are often associated with vernal pools, seasonal wetlands that harbor rare and endemic plants and animals. The processes that form and maintain the mound-pool complexes have not yet been conclusively identified, even though such information is necessary to understand the effects that land use and climate change may have on the resilience and longevity of these landscapes. One hypothesis for the origin and persistence of Mima mound- vernal pool systems (termed the Fossorial Rodent Hypothesis) proposes that burrowing organisms such as pocket gophers (Rodentia: Geomyidae) maintain and possibly create the mounds by preferentially translocating soils towards mound centers as an adaptive response to high water tables. In order to investigate this hypothesis, the topographic characteristics and aboveground gopher activity of one of the largest remaining Mima mound-vernal pool systems in California were studied. Detailed topographic information for the mound-pool systems was obtained via an airborne-based LIDAR (Light Detection and Ranging) survey of a 25km2 region near Merced, CA. An object-oriented classification scheme, which combined different scale, shape, and spectral parameters, was employed in order to characterize the mounds. Based on the initial classification results, roughly 275,000 mounds were identified, indicating a mound density of 11,000km-2. Within the larger study area, gopher sediment transport was monitored on a 3507m2 site by conducting periodic surveys of sediment mounds created by gopher activity using a Global Positioning System and mass measurements. Downslope erosion rates (off Mima mounds) were estimated using a mass balance model which incorporates a diffusive sediment transport law. The median calculated net downslope erosion rate was 15 cm of soil per 1000 years, while the measured rate of aboveground gopher sediment movement was

  8. Models of Formation and Activity of Spring Mounds in the Mechertate-Chrita-Sidi El Hani System, Eastern Tunisia: Implications for the Habitability of Mars

    PubMed Central

    Essefi, Elhoucine; Komatsu, Goro; Fairén, Alberto G.; Chan, Marjorie A.; Yaich, Chokri

    2014-01-01

    Spring mounds on Earth and on Mars could represent optimal niches of life development. If life ever occurred on Mars, ancient spring deposits would be excellent localities to search for morphological or chemical remnants of an ancient biosphere. In this work, we investigate models of formation and activity of well-exposed spring mounds in the Mechertate-Chrita-Sidi El Hani (MCSH) system, eastern Tunisia. We then use these models to explore possible spring mound formation on Mars. In the MCSH system, the genesis of the spring mounds is a direct consequence of groundwater upwelling, triggered by tectonics and/or hydraulics. As they are oriented preferentially along faults, they can be considered as fault spring mounds, implying a tectonic influence in their formation process. However, the hydraulic pressure generated by the convergence of aquifers towards the surface of the system also allows consideration of an origin as artesian spring mounds. In the case of the MCSH system, our geologic data presented here show that both models are valid, and we propose a combined hydro-tectonic model as the likely formation mechanism of artesian-fault spring mounds. During their evolution from the embryonic (early) to the islet (“island”) stages, spring mounds are also shaped by eolian accumulations and induration processes. Similarly, spring mounds have been suggested to be relatively common in certain provinces on the Martian surface, but their mode of formation is still a matter of debate. We propose that the tectonic, hydraulic, and combined hydro-tectonic models describing the spring mounds at MCSH could be relevant as Martian analogs because: (i) the Martian subsurface may be over pressured, potentially expelling mineral-enriched waters as spring mounds on the surface; (ii) the Martian subsurface may be fractured, causing alignment of the spring mounds in preferential orientations; and (iii) indurated eolian sedimentation and erosional remnants are common features on

  9. Models of formation and activity of spring mounds in the mechertate-chrita-sidi el hani system, eastern Tunisia: implications for the habitability of Mars.

    PubMed

    Essefi, Elhoucine; Komatsu, Goro; Fairén, Alberto G; Chan, Marjorie A; Yaich, Chokri

    2014-01-01

    Spring mounds on Earth and on Mars could represent optimal niches of life development. If life ever occurred on Mars, ancient spring deposits would be excellent localities to search for morphological or chemical remnants of an ancient biosphere. In this work, we investigate models of formation and activity of well-exposed spring mounds in the Mechertate-Chrita-Sidi El Hani (MCSH) system, eastern Tunisia. We then use these models to explore possible spring mound formation on Mars. In the MCSH system, the genesis of the spring mounds is a direct consequence of groundwater upwelling, triggered by tectonics and/or hydraulics. As they are oriented preferentially along faults, they can be considered as fault spring mounds, implying a tectonic influence in their formation process. However, the hydraulic pressure generated by the convergence of aquifers towards the surface of the system also allows consideration of an origin as artesian spring mounds. In the case of the MCSH system, our geologic data presented here show that both models are valid, and we propose a combined hydro-tectonic model as the likely formation mechanism of artesian-fault spring mounds. During their evolution from the embryonic (early) to the islet ("island") stages, spring mounds are also shaped by eolian accumulations and induration processes. Similarly, spring mounds have been suggested to be relatively common in certain provinces on the Martian surface, but their mode of formation is still a matter of debate. We propose that the tectonic, hydraulic, and combined hydro-tectonic models describing the spring mounds at MCSH could be relevant as Martian analogs because: (i) the Martian subsurface may be over pressured, potentially expelling mineral-enriched waters as spring mounds on the surface; (ii) the Martian subsurface may be fractured, causing alignment of the spring mounds in preferential orientations; and (iii) indurated eolian sedimentation and erosional remnants are common features on Mars

  10. A Preliminary Study on Elimination of Colonies of the Mound Building Termite Macrotermes gilvus (Hagen) Using a Chlorfluazuron Termite Bait in the Philippines

    PubMed Central

    Dhang, Partho

    2011-01-01

    The effectiveness of a chlorfluazuron termite bait in eliminating colonies of the termite species Macrotermes gilvus (Hagen) was evaluated under field conditions. Three active termite mounds were chosen for this study, two acted as test mounds and the other as the control. Four In-Ground Stations (IGS) were installed around each mound. Interception occurred almost immediately in all the stations, which were subsequently baited. The control mound was fed a bait matrix lacking the active ingredient. Stations were re-baited every 2 weeks for 10–12 weeks until bait consumption ceased in the test mounds. The mounds were left undisturbed for four more weeks before being destructively sampled. The desiccated remains of workers, soldiers, late instars and queen were found upon sampling the treated mounds. A few live termites were located in one treated mound but were darkly pigmented indicating bait consumption. The control mound remained healthy and did not show any visible sign of negative impact. The bait successfully suppressed or eliminated both M. gilvus colonies within 16 weeks from commencement of feeding.

  11. Stratigraphy and petrology of petroleum-producing Waulsortian-type carbonate mounds in Fort Payne formation (Lower Mississippian) of north-central Tennessee

    SciTech Connect

    MacQuown, W.C.; Perkins, J.H.

    1982-08-01

    The petroleum-producing subsurface mounds of the Fort Payne Formation (Lower Mississippian) in north-central Tennessee represent a facies that is generally absent or poorly developed in surface sections to the west, near the Cincinnati arch, and to the east, in the Appalachian fold belt. The cross section and isopach maps of the Fort Payne mound unit and submound unit, and a structural map of the underlying Chattanooga Shale provide evidence for predicting undiscovered mounds by interpolating and extrapolating along several northeast-southwest mound trends. Interpretations are based on subsurface data, and they are reinforced by a comparison with the analogous Waulsortian mounds and lenses of the same age in Europe. Waulsortian-type mounds are widespread on the surface of western Europe and North America. However, differences in morphology, porosity development, and the emplacement of petroleum in Fort Payne mounds are related to local paleogeography in a shallow cratonic-shelf sea subjected to cyclic regression and transgression due to regional tectono-eustatic events. Fort Payne mounds produced more than 5.5 million bbl of oil through 1980. Although the source beds have not been identified, petroleum may have been derived from the submound or mound units of the Fort Payne Formation, or from the underlying Chattanooga Shale.

  12. Evidence from Polymict Ureilite Meteorites for a Single "Rubble-Pile" Ureilite Parent Asteroid Gardened by Several Distinct Impactors

    NASA Technical Reports Server (NTRS)

    Downes, Hilary; Mittlefehldt, David W.; Kita, Noriko T.; Valley, John W.

    2008-01-01

    to a "rubble-pile" body that had material of a wide variety of compositions and shock states present on its surface. The analysed polymict ureilite meteorites represent regolith that subsequently formed on this asteroidal surface, including impact-derived material from at least six different meteoritic sources.

  13. Accelerated Clean-up of the United States Department of Energy, Mound Nuclear Weapons Facility in Miamisburg, Ohio

    SciTech Connect

    Lehew, J.G.; Bradford, J.D.; Cabbil, C.C.

    2006-07-01

    CH2M HILL is executing a performance-based contract with the United States Department of Energy to accelerate the safe closure of the nuclear facilities at the former Mound plant in Miamisburg, Ohio. The contract started in January 2003 with a target completion date of March 31, 2006. Our accelerated baseline targets completion of the project 2 years ahead of the previous baseline schedule, by spring 2006, and for $200 million less than previous estimates. This unique decommissioning and remediation project is located within the City of Miamisburg proper and is designed for transfer of the property to the Miamisburg Mound Community Improvement Corporation for industrial reuse. The project is being performed with the Miamisburg Mound Community Improvement Corporation and their tenants co-located on the site creating significant logistical, safety and stakeholder challenges. The project is also being performed in conjunction with the United States Department of Energy, United States Environmental Protection Agency, and the Ohio Environmental Protection Agency under the Mound 2000 regulatory cleanup process. The project is currently over 95% complete. To achieve cleanup and closure of the Mound site, CH2M HILL's scope includes: - Demolition of 64 nuclear, radiological and commercial facilities - Preparation for Transfer of 9 facilities (including a Category 2 nuclear facility) to the Miamisburg Mound Community Improvement Corporation for industrial reuse - Removal of all above ground utility structures and components, and preparation for transfer of 9 utility systems to Miamisburg Mound Community Improvement Corporation - Investigation, remediation, closure, and documentation of all known Potential Release Sites contaminated with radiological and chemical contamination (73 identified in original contract) - Storage, characterization, processing, packaging and shipment of all waste and excess nuclear materials - Preparation for Transfer of the 306 acre site to the

  14. Technical Review Report for the Mound 1KW Package Safety Analysis Report for Packaging Addendum No. 1, through Revision b

    SciTech Connect

    DiSabatino, A; West, M; Hafner, R; Russell, E

    2007-10-04

    This Technical Review Report (TRR) documents the review, performed by the Lawrence Livermore National Laboratory (LLNL) staff, at the request of the U.S. Department of Energy (DOE), on the 'Mound 1KW Package Safety Analysis Report for Packaging, Addendum No. 1, Revision b', dated May 2007 (Addendum 1). The Mound 1KW Package is certified by DOE Certificate of Compliance (CoC) number USA/9516/B(U)F-85 for the transportation of Type B quantities of plutonium heat source material. The safety analysis of the package is documented in the 'Safety Analysis Report for Packaging (SARP) for the Mound 1KW Package' (i.e., the Mound 1KW SARP, or the SARP). Addendum 1 incorporates a new fueled capsule assembly payload. The following changes have been made to add this payload: (1) The primary containment vessel (PCV) will be of the same design, but will increase in height to 11.16 in.; (2) A new graphite support block will be added to support up to three fueled capsule assemblies per package; (3) The cutting groove height on the secondary containment vessel (SCV) will be heightened to accommodate the taller PCV; and (4) A 3.38 in. high graphite filler block will be placed on top of the PCV. All other packaging features, as described in the Mound 1KW SARP [3], remain unchanged. This report documents the LLNL review of Addendum 1[1]. The specific review for each SARP Chapter is documented herein.

  15. An enquiry into the respiratory health effects on a rural community of a soil mound erected close to residential property.

    PubMed

    Olowokure, B; Wardle, S A; Beaumont, M; Duggal, H V; Colling, G

    2005-03-01

    The health concerns of a rural community were investigated following the erection of a soil mound in close proximity to residential property. Retrospective comparisons were made of respiratory and non-respiratory consultations with general practitioners between the exposed population and a sociodemographically similar comparison population. A 2-year period was examined, 1 year before and 1 year after the mound was erected. In the 1-year period prior to erection of the mound, similar consultation rates for both respiratory and non-respiratory conditions were observed in both populations. In the 1-year period following erection of the mound, the exposed population was more likely to consult for respiratory conditions than the comparison population (OR=4.10, 95% CI 2.26-7.44). No differences were observed for non-respiratory conditions. We identified a significant increase in respiratory consultations in the exposed population following erection of the soil mound. Limitations associated with this type of study should be considered when interpreting the results. PMID:15661133

  16. Ft-Ir Spectroscopic Analysis of Potsherds Excavated from the First Settlement Layer of Kuriki Mound, Turkey

    NASA Astrophysics Data System (ADS)

    Bayazit, Murat; Isik, Iskender; Cereci, Sedat; Issi, Ali; Genc, Elif

    The region covering Southeastern Anatolia takes place in upper Mesopotamia, so it has numerous cultural heritages due to its witness to various social movements of different civilizations in ancient times. Kuruki Mound is located on the junction point of Tigris River and Batman Creek, near Oymatas village which is almost 15 km to Batman, Turkey. The mound is dated back to Late Chalcolithic. Archaeological excavations are carried out on two hills named as “Kuriki Mound-1” and “Kuriki Mound-2” in which 4-layer and 2-layer settlements have been revealed, respectively. This region will be left under the water by the reservoir lake of Ilısu Dam when its construction is completed. Thus, characterization of ancient materials such as potsherds, metals and skeleton ruins should be rapidly done. In this study, 12 potsherds excavated from Layer-1 (the first settlement layer after the surface) in Kuriki Mound-2 were investigated by FT-IR spectrometry. Energy dispersive X-ray fluorescence (EDXRF) and X-ray diffraction (XRD) analyses were used as complementary techniques in order to expose chemical and mineralogical/phase contents, respectively. Obtained results showed that the potteries have been produced with calcareous clays and they include moderate amounts of MgO, K2O, Na2O and Fe2O3 in this context. Additionally, high temperature phases have also been detected with XRD analyses in some samples.

  17. Cryogenesis study of a pingo-like mound in the Akkol valley of the Russian Altai Mountains

    NASA Astrophysics Data System (ADS)

    Iwahana, G.; Fukui, K.; Fujii, Y.; Ostanin, O.; Mikhailov, N.

    2008-12-01

    Vertical outcrop of a pingo-like mound found in the Akkol valley of the Russian Altai Mountains is described. Several pingo-like mounds were found on the valley floor at about 2300 m ASL. They are 5 - 10 m high and up to 50 m in diameter. Part of a 5 m mound had collapsed into adjacent pond with continuous water supply from streams on the mountain ridge nearby and top 4 m section had been revealed. Highly complex combinations of segregated ice lenses were observed in the outcrop. Ice veins, which are consisted by a number of thick ice lenses, develop radially from the core of the mound. The areas in-between the ice veins had fine parallel lenticular cryostructure. Surface soil layer (about one meter) and patchy soil parts between ice lenses were made of fine till of lacustrine sediments. delta O18 values of water from these ice lenses range from -15 to -18. Spatial distribution of the isotope values was well correlated with the spatial pattern of the ice lenses"f distribution. In addition to segregation of ice lenses perpendicular to the temperature gradient, contribution of relatively rapid formation of ice in radial direction from the core of the mound can be large in this three dimensional frost heave phenomenon.

  18. RCRA Facility Investigation/Remedial Investigation Report with Baseline Risk Assessment for the Central Shops Burning/Rubble Pit (631-6G), Volume 1 Final

    SciTech Connect

    1996-04-01

    The Burning/Rubble Pits at the Savannah River Site were usually shallow excavations approximately 3 to 4 meters in depth. Operations at the pits consisted of collecting waste on a continuous basis and burning on a monthly basis. The Central Shops Burning/Rubble Pit 631- 6G (BRP6G) was constructed in 1951 as an unlined earthen pit in surficial sediments for disposal of paper, lumber, cans and empty galvanized steel drums. The unit may have received other materials such as plastics, rubber, rags, cardboard, oil, degreasers, or drummed solvents. The BRP6G was operated from 1951 until 1955. After disposal activities ceased, the area was covered with soil. Hazardous substances, if present, may have migrated into the surrounding soil and/or groundwater. Because of this possibility, the United States Environmental Protection Agency (EPA) has designated the BRP6G as a Solid Waste Management Unit (SWMU) subject to the Resource Conservation Recovery Act/Comprehensive Environmental Response, Compensation and Liability Act (RCRA/CERCLA) process.

  19. Discovery of hydrothermally active and extinct talc mounds on the Mid-Cayman Rise

    NASA Astrophysics Data System (ADS)

    Hodgkinson, M.; Murton, B. J.; Roberts, S.

    2013-12-01

    Since 1977, hydrothermal vents have been the subject of intense scientific interest due to their role in cooling the oceanic crust and global geochemical cycles. Until now, two types of hydrothermal system have been identified: one, driven by magmatic heat extruding ';black smoker' fluids; and another, involving serpentinisation of ultramafic rocks and the precipitation of carbonate/brucite chimneys. Here, we present details of a new, off-axis type of hydrothermal system consisting of mounds of predominately botryoidal talc (a magnesium-silicate) with accessory silica and copper sulphides, and chimneys exhaling fluids of moderate temperature and pH. Discovered on the Mid-Cayman Rise (MCR) in 2010, the Von Damm Vent Field (VDVF) features a NNW-ESE-trending line of four overlapping cones, the largest of which is 75 m high by 150 m in diameter. The VDVF is hosted in the gabbroic footwall of the Mount Dent Oceanic Core Complex (MDOCC), which includes serpentinised peridotite at depth. The largest cone vents clear fluids from two main orifices at its summit, with primary temperatures of 215°C. Elsewhere, both focussed and diffuse flow areas emit fluids with temperatures of up to 150°C. The surrounding ~1 m thick pelagic sediment contains abundant pockmarks that emit methane-rich fluids at temperatures of less than 10°C. During the return to the MCR in early 2013, several other talc mounds were discovered within a kilometre of the active VDVF. These inactive mounds also comprise an assemblage of botryoidal talc, silica, disseminated sulphides (including chalcopyrite) and sulphates. One of these mounds (Mystic Mount) is double the volume of the active VDVF. The unique dominance of talc as the major mineral forming the hydrothermal structures indicates unusual vent fluid compositions that are able to carry both copper (at high-temperatures) and precipitate magnesium silicate. Thermodynamic modelling indicates that talc precipitates on mixing a moderately acidic, silica

  20. Rebuilding from the Rubble.

    ERIC Educational Resources Information Center

    Harper, John

    1992-01-01

    After tornado leveled Grand Prairie Elementary School (Joliet, Illinois), concerted effort by architects and the school community paid off when new school was opened two years later. Hallways in new building are staggered throughout school to avoid the creation of wind tunnels in event of another tornado. Guidelines for disaster preparations…

  1. Double the Rubble

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This artist's conception shows the closest known planetary system to our own, called Epsilon Eridani. Observations from NASA's Spitzer Space Telescope show that the system hosts two asteroid belts, in addition to previously identified candidate planets and an outer comet ring.

    Epsilon Eridani is located about 10 light-years away in the constellation Eridanus. It is visible in the night skies with the naked eye.

    The system's inner asteroid belt appears as the yellowish ring around the star, while the outer asteroid belt is in the foreground. The outermost comet ring is too far out to be seen in this view, but comets originating from it are shown in the upper right corner.

    Astronomers think that each of Epsilon Eridani's asteroid belts could have a planet orbiting just outside it, shepherding its rocky debris into a ring in the same way that Jupiter helps keep our asteroid belt confined. The planet near the inner belt was previously identified in 2000 via the radial velocity, or 'star wobble,' technique, while the planet near the outer belt was inferred when Spitzer discovered the belt.

    The inner belt orbits at a distance of about 3 astronomical units from its star or about the same position as the asteroid belt in our own solar system (an astronomical unit is the distance between Earth and our sun). The second asteroid belt lies at about 20 astronomical units from the star, or a position comparable to Uranus in our solar system. The outer comet ring orbits from 35 to 90 astronomical units from the star; our solar system's analogous Kuiper Belt extends from about 30 to 50 astronomical units from the sun.

  2. Vertical movements of frost mounds in subarctic permafrost regions analyzed using geodetic survey and satellite interferometry

    NASA Astrophysics Data System (ADS)

    Beck, I.; Ludwig, R.; Bernier, M.; Strozzi, T.; Boike, J.

    2015-08-01

    Permafrost-affected soils cover about 40-45 % of Canada. The environment in such areas, especially those located within the discontinuous permafrost zone, has been impacted more than any other by recorded climatic changes. A number of changes, such as surface subsidence and the degradation of frost mounds due to permafrost thawing, have already been observed at many locations. We surveyed three frost mounds (lithalsas) in the subarctic, close to Umiujaq in northern Quebec, using high-precision differential global positioning system (d-GPS) technology during field visits in 2009, 2010 and 2011, thus obtaining detailed information on their responses to the freezing and thawing that occur during the course of the annual temperature cycle. Seasonal pulsations were detected in the frost mounds, and these responses were shown to vary with their state of degradation and the land cover. The most degraded lithalsa showed a maximum amplitude of vertical movement (either up or down) between winter (freezing) and summer (thawing) of 0.19 ± 0.09 m over the study period, while for the least degraded lithalsa this figure was far greater (1.24 ± 0.47 m). Records from areas with little or no vegetation showed far less average vertical movement over the study period (0.17 ± 0.03 m) than those with prostrate shrubs (0.56 ± 0.02 m), suggesting an influence from the land cover. A differential interferometric synthetic aperture radar (D-InSAR) analysis was also completed over the lithalsas using selected TerraSAR-X images acquired from April to October 2009 and from March to October 2010, with a repeat cycle of 11 days. Interferograms with baselines shorter than 200 m were computed revealing a generally very low interferometric coherence, restricting the quantification of vertical movements of the lithalsas. Vertical surface movements of the order of a few centimeters were recorded in the vicinity of Umiujaq.

  3. Diagenesis of silica-rich mound-bedded chalk, the Coniacian Arnager Limestone, Denmark

    NASA Astrophysics Data System (ADS)

    Madsen, H. B.; Stemmerik, L.; Surlyk, F.

    2010-01-01

    The Coniacian Arnager Limestone Formation is exposed on the Danish island of Bornholm in the Baltic Sea. It is composed of mound-bedded siliceous chalk, and X-ray diffraction and scanning electron microscopy indicate a content of 30-70% insoluble minerals, including authigenic opal-CT, quartz, clinoptilolite, feldspars, calcite, dolomite, and barite. Opal-CT and clinoptilolite are the most common and constitute 16-53% and 2-9%, respectively. The content of insoluble minerals varies laterally both within the mounds and in planar beds, and the opal-CT content varies by up to 10% vertically. The mounds consist of two microfacies, spiculitic wackestone and bioturbated spiculitic wackestone, containing 10-22% and 7-12% moulds after spicules, respectively. Subsequent to deposition and shallow burial, dissolution of siliceous sponge spicules increased the silica activity of the pore water and initiated precipitation of opal-CT. The opal-CT formed at temperatures around 17 °C, the precipitation lowered the silica activity and the Si/Al ratio of the pore water, resulting in precipitation of clinoptilolite, feldspar and smectite. Calcite formed synchronously with the latest clinoptilolite. Minor amounts of quartz precipitated in pore water with low silica activity during maximum burial, probably to depths of 200-250 m. The dissolution of sponge spicules and decomposition of the sponge tissue also resulted in the release of Ba 2+, Sr 2+, Mg 2+, Ca 2+ and CO 32-, facilitating precipitation of barite and dolomite. Precipitation of especially opal-CT reduced the porosity to an average of 40% and cemented the limestone. The study highlights the diagenetic pathways of bio-siliceous chalk and the effects on preservation of porosity and permeability.

  4. Early Carboniferous (Tournasian-early Visean) global paleogeography, Paleostorm tracts, and the distribution of Waulsortian and Waulsortian-like carbonate mud mounds

    SciTech Connect

    King, D.T. Jr. )

    1990-05-01

    Tournasian-early Visean mud mounds (i.e., Waulsortian and Waulsortian-like mounds) are unlike other carbonate buildups in the stratigraphic record because they lack an identifiable frame-building organism. Waulsortian mounds are comprised mainly of carbonate mud; Waulsortian-like mounds are mud-rich and contain a significant percent of skeletal grains, especially crinoids and bryozoa. This study has revealed that all of the reported Waulsortian and Waulsortian-like mounds developed in low paleolatitudes either on the southern shelf margin of the Laurussian paleocontinent or in the Laurussian interior seaway. Waulsortian and Waulsortian-like mounds are specifically not present in low-latitude regions of other paleocontinents. As Tournasian-early Visean carbonate deposition was widespread in the range of 30{degree}N to 10{degree}S, the very restricted paleogeographic distribution of Waulsortian and Waulsortian-like mound locations suggests a mechanism or set of conditions that effectively limited the distribution of mud mounds. Considering the Tournasian-early Visean distribution of paleocontinents and the principles that govern the movement of modern hurricanes, tropical storms, and winter storms, the tracts of hurricanes, tropical storms, and winter storms probably crossed all main submerged paleocontinental areas except the southern Laurussian shelf margin and the Laurussian interior seaway, the two areas where mud mounds developed. The lack of storm energy in these two large areas of Laurussia provided long-term stability and thus enhanced the growth prospects of the frame-deficient Waulsortian and Waulsortian-like mud mounds. Lack of extensive periodic wave reworking and other storm-induced devastation helps to account for enigmatic features such as general mound symmetry, great size, high depositional relief (as much as 220 m), and side steepness (as steep as 50{degree}).

  5. Mound Spring Complexes in Central Australia: An Analog for Martian Groundwater Fed Outflow Channels?

    NASA Technical Reports Server (NTRS)

    Clarke, J. D. A.; Stoker, C.

    2003-01-01

    The arid inland of Australia contains a diversity of landscapes and landscape processes, often of great antiquity, extending back to the Mesozoic and Paleozoic. The potential of this landscape as a source of Mars analogs has, however, been little explored. The few examples studied so far include radiation-tolerant microbes in thermal springs and hematite-silica hydrothermal alteration near Arkaroola in the Finders Ranges, and aeolian landforms at Gurra Gurra water hole the north east of Arkaroola. Further Australian Mars analog studies were provided by the studies of Bourke and Zimbelman of the paleoflood record of the Todd and Hale Rivers in central Australia. To facilitate study of such analogues, Mars Society Australia has embarked on a project to construct a Mars Analog Research Station near Arkaroola. The international scientific community will soon have the opportunity to participate in Mars analog studies in central Australia utilizing this facility. An area of considerable Mars analog potential is the mound spring complexes that occur at the margins of the Great Artesian Basin (GAB) which underlies 22% of the Australian continent and covers 1.7 million km2. The mound springs are formed when ground water flows to a topographic low, and subsurface strata dips up causing a hydrological head at the surface. Minerals precipitated at the spring discharge zone form low mesas or "mounds", the height of which are controlled by the hydrological head. This paper describes the Dalhousie Mound Spring Complex (DMC) in the northern part of South Australia (Figure 1), and its potential as a Mars analog. Hydrogeology: The DMC consists of a cluster of more than 60 active springs formed by natural discharge from the GAB). Total measured discharge from the GAB is 1.74 GL per day, estimated unfocussed natural leakage through the aquaclude is thought be approximately equal to this figure. Some 54 ML per day are currently discharged by the DMC, 3% of the measured total. The

  6. Drowning of algal mounds: records from the Upper Carboniferous Lower Pseudoschwagerina Limestone, Carnic Alps, Austria

    NASA Astrophysics Data System (ADS)

    Samankassou, Elias

    1999-09-01

    Anthracoporella algal mounds, up to 22 m thick, occur within the cyclic sequences of the Lower Pseudoschwagerina Limestone (uppermost Carboniferous), Carnic Alps (Austria). Their depositional environment lay between the wave base and the base of the photic zone. The algal mounds are overlain by dark, well-bedded, cherty wackestones and packstones. The cherty limestones contain cephalopods, thick-shelled brachiopods, and sponge spicules and lack Anthracoporella in growth position. They are typical deeper-water sediments, deposited below the photic zone. This sequence records drowning episodes; the shallow-water algal mounds were drowned by relative rise of sea level as sea-bottom production shut down below the photic zone. The sedimentological and paleontological evidence of drowning are supported by geochemical data of two measured sections. The mean sulfur content of the well-oxygenated algal limestones is 0.02% for both sections; the TOC values are 0.17% for the section AI and 0.10% for the section AR. The S contents of the cherty limestones are approximately twice as high with values of 0.48 and 0.05% for the respective sections. TOC values of the cherty limestones are also significantly higher, with 0.30 and 0.51% contents for the respective sections. The cherty limestones document the termination of the mounds and the demise of reef-building algae in each cycle. This interval is therefore termed `shroud facies'. The rapid sea-level rise reported is a further proof for high-magnitude sea-level fluctuations in intervals of glacio-eustasy. The documented drowning mode is novel through the definable interval of drowning, the repeated events during a short time interval, the full record of pre-, syn-, and post-drowning deposits, and the unequivocal attribution to glacio-eustatic sea-level rise. This mode seems to be characteristic of an icehouse period and clearly differs from the drowning mode in greenhouse periods which is often gradual, lacks an unequivocal

  7. Beach nourishment alternative assessment to constrain cross-shore and longshore sediment transport

    USGS Publications Warehouse

    Karasu, Servet; Work, Paul; Uzlu, Ergun; Kankal, Murat; Yuksek, Omer

    2016-01-01

    A combined field and laboratory investigation was conducted to assess five options for creation of a recreational beach on a steep, armored shoreline on the eastern Black Sea coast. All designs incorporated a beach nourishment project placed between two existing, shore-normal, rubble-mound groins. Alternatives included the placement of a nearshore berm, longshore extensions added to the existing groins, and shore-parallel breakwaters. Several alternatives are reviewed for quantifying the performance of each design, including assessment of the change in shoreline position and project volume retained between the groins. Dimensionless benefits and benefit-cost ratios are quantified, and recommendations made on how to select the best outcome from a benefit-to-cost standpoint when options including hard structures are incorporated into a beach nourishment project design.

  8. Geomicrobiology of Carbonate Mounds in the Gulf of Cadiz off Morocco: Biogeochemistry, Mineralogy and Microbial Community Composition

    NASA Astrophysics Data System (ADS)

    Templer, S. P.; Stadnitskaia, A.; Maignien, L.; Vasconcelos, C.; McKenzie, J. A.

    2007-12-01

    Carbonate mud mounds, found in marine environments from shallow- to deep-water settings, span from Proterozoic to recent times. Mound building seems to be a fundamental but still enigmatic strategy for life. Various arguments suggest that microorganisms are playing an important role in the reef development, biodiversity and mound formation. Therefore, it is important to evaluate the microbial mediated processes of carbonate precipitation. The Pen Duick Escarpment off Morocco consists of recent carbonate mounds in water depths of 500-600 m, flanked by giant mud volcanoes. Subsequent cruises have confirmed the colonization by dominantly lifeless cold- water corals and have unveiled extensive fields of seep-related carbonates in off-reef regions. Three (from 350 to 640 cm long) piston cores, coming from different sites on these juvenile mounds, were sampled and analyzed for mineralogy, stable isotopes composition, geochemistry, and microbial communities. In order to define the primary microbial community involved in carbonate precipitation, we did direct culturing, DNA isolation and PCR analysis of functional genes, including 16S rRNA gene analysis. Most of the sediment comprises pelagic calcite (coccoliths), detrital quartz and authigenic dolomite, often observed encasing coccoliths. Stable carbon isotope values of the bulk carbonate range from -7 to -15‰ indicating the involvement of microbes in the production of bicarbonate ions. In this paper, we will show and discuss multidisciplinary data obtained after several cruises aimed to elucidate the impact of microorganisms on the construction of these carbonate mounds. The special emphasis in this research will be on the correlation between microbial ecosystems and their metabolic influence on mineral formation and diagenesis.

  9. Paleoseawater density reconstruction and its implication for cold-water coral carbonate mounds in the northeast Atlantic through time

    NASA Astrophysics Data System (ADS)

    Rüggeberg, Andres; Flögel, Sascha; Dullo, Wolf-Christian; Raddatz, Jacek; Liebetrau, Volker

    2016-03-01

    Carbonate buildups and mounds are impressive biogenic structures throughout Earth history. In the recent NE Atlantic, cold-water coral (CWC) reefs form giant carbonate mounds of up to 300 m of elevation. The expansion of these coral carbonate mounds is paced by climatic changes during the past 2.7 Myr. Environmental control on their development is directly linked to controls on its main constructors, the reef-building CWCs. Seawater density has been identified as one of the main controlling parameter of CWC growth in the NE Atlantic. One possibility is the formation of a pycnocline above the carbonate mounds, which is increasing the hydrodynamic regime, supporting elevated food supply, and possibly facilitating the distribution of coral larvae. The potential to reconstruct past seawater densities from stable oxygen isotopes of benthic foraminifera has been further developed: a regional equation gives reliable results for three different settings, peak interglacials (e.g., Holocene), peak glacials (e.g., Last Glacial Maximum), and intermediate setting (between the two extremes). Seawater densities are reconstructed for two different NE Atlantic CWC carbonate mounds in the Porcupine Seabight indicating that the development of carbonate mounds is predominantly found at a seawater density range between 27.3 and 27.7 kg m-3 (σΘ notation). Comparable to recent conditions, we interpret the reconstructed density range as a pycnocline serving as boundary layer, on which currents develop, carrying nutrition and possibly coral larvae. The close correlation of CWC reef growth with reconstructed seawater densities through the Pleistocene highlights the importance of pycnoclines and intermediate water mass dynamics.

  10. lagC-null and gbf-null cells define key steps in the morphogenesis of Dictyostelium mounds.

    PubMed

    Sukumaran, S; Brown, J M; Firtel, R A; McNally, J G

    1998-08-01

    The transition to multicellularity is a key feature of the Dictyostelium life cycle, and two genes, gbf and lagC, are known to play pivotal roles in regulating this developmental switch. lagC-null and gbf-null cells fail to induce cell-type-specific genes ordinarily expressed during multicellular development. The null mutants also share a similar morphological phenotype: mutant cells repeatedly aggregate to form a loose mound, disperse, and reform a mound, rather than proceeding to form a tip. To characterize defects in morphogenesis in these mutants, we examined cell motion in the mutant mounds. In analogy with the failed transition in gene expression, we found that lagC-null and gbf-null mounds failed to make a morphogenetic transition from random to rotational motion normally observed in the parent strain. One reason for this was the inability of the mutant mounds to establish a single, dominant signaling-wave center. This defect of lagC-null or gbf-null cells could be overcome by the addition of adenosine, which alters cAMP signaling, but then even in the presence of apparently normal signaling waves, cell motility was still aberrant. This motility defect, as well as the signaling-wave defect, could be overcome in lagC-null cells by overexpression of GBF, suggesting that lagC is dispensable if GBF protein levels are high enough. This set of morphogenetic defects that we have observed helps define key steps in mound morphogenesis. These include the establishment of a dominant signaling-wave center and the capacity of cells to move directionally within the cell mass in response to guidance cues. PMID:9698452

  11. >Mud mounds on the continental slope, northwestern Gulf of Mexico and their relation to hydrates and seafloor instability

    SciTech Connect

    Neurauter, T.W.

    1988-01-01

    High resolution seismic data delineate acoustically amorphous mounded structures on the continental slope of the Northwest Gulf of Mexico. The thermogenic gas hydrates reported from Green Canyon Block 184 are associated with one of these mounds. This particular mound occurs in a highly faulted area and overlies an extensive chaotic seismic facies. Gas and fluids are migrating up the fault plane to the sea floor. The relief of the mound is partially the result of the throw of the associated faults, but also to a combination of other factors such as the upwelling of gaseous muds, in-place expansion of the hydrates and the generation of diagenic carbonates. The acoustic signature of the known hydrate accumulation of Green Canyon Block 184 was applied to high resolution data in Mississippi Canyon Block 798 and 799 in an attempt to predict the occurrence of hydrates. Piston cores within an acoustically amorphous mound in Block 798 encountered extremely gassy sediments with sizeable chunks of white, presumably biogenic hydrates. The geologic setting in Block 798 was similar to Green Canyon 184 with complex faulting and subsurface sequences of thick chaotic facies. The venting of gas and fluids from overpressured zones appears to be the common factor for all mounds thereby making them mud diapir/mud volcano type structures. No evidence of seafloor instability was directly related to the presence or possible presence of gas hydrates. However, if it can be established that massive hydrate formation exist on the continental slope, then a substantial lowering of sea level such as occurred in the late Pleistocene, would result in decomposition of the hydrates and trigger mass wasting. Such a mechanism could explain abundance of buried erosional scars along the continental slope.

  12. Effects of variations in hydrogeological parameters on water-table mounding in sandy loam and loamy sand soils beneath stormwater infiltration basins

    NASA Astrophysics Data System (ADS)

    Thompson, Anita; Nimmer, Mike; Misra, Debasmita

    2010-03-01

    The two-dimensional variably-saturated numerical model HYDRUS-2D, previously calibrated to recharge events from an infiltration basin, was used to predict water-table mounding under hypothetical basin design scenarios, and the primary factors that affect water-table mounding were evaluated. Infiltration basins are often utilized in urban environments to recharge stormwater to the aquifer. As a result of localized recharge beneath these basins, mound formation may reduce the thickness of the unsaturated zone available to filter pollutants and may reduce the infiltration rate of the basin. Understanding the effects of various physical factors on water-table mound formation is important for infiltration basin siting. For sandy loam and loamy sand subsurface materials, mound heights increased as the thickness of both the unsaturated and saturated zones decreased. Mound heights increased as the initial soil moisture, basin size and ponding depth increased. A thin sedimentation layer on the basin floor delayed mound formation, but only slightly decreased the maximum mound height. This analysis could be used in future selection of infiltration basin locations; however, the analysis is limited to conditions that represent only a select range of basin design conditions and parameters typical of a glacial till environment in Wisconsin, USA.

  13. Incineration of LWR-type waste in the Mound Cyclone Incinerator: a feasibility study

    SciTech Connect

    Alexander, B.M.

    1980-12-23

    The Mound Cyclone Incinerator has been demonstrated for several years for combustion of radwaste containing plutonium. It is now being developed for volume reduction of radwaste from light water reactor (LWR) facilities containing mixed beta- and gamma-emitters. To this end, a laboratory-scale feasibility study has been developed and executed. Development of the feasibility study was based on known characteristics of LWR waste and on operating data compiled for the Mound Cyclone Incinerator since 1975. Feed spiked with several isotopes found in LWR waste was burned in the laboratory-scale cyclone incinerator, and samples collected and analyzed. From these data, the applicability of cyclone incineration was demonstrated, and an efficient scrub liquor composition was chosen for the offgas treatment system. A Health Physics survey of the incinerator system after incineration of 220 ..mu..Ci of beta/gamma activity showed no exposure readings above background levels. Supplemental experiments were also performed to determine the effect of the chemical form of iodine on its volatility, as well as to calculate the cost-benefit relationship for the addition of potassium iodide to scrub liquor.

  14. Struvite for composting of agricultural wastes with termite mound: Utilizing the unutilized.

    PubMed

    Karak, Tanmoy; Sonar, Indira; Nath, Jyoti Rani; Paul, Ranjit Kumar; Das, Sampa; Boruah, Romesh Kumar; Dutta, Amrit Kumar; Das, Kuntal

    2015-01-01

    Although, compost is the store house of different plant nutrients, there is a concern for low amount of major nutrients especially nitrogen content in prepared compost. The present study deals with preparation of compost by using agricultural wastes with struvite (MgNH4PO4·6H2O) along with termite mound. Among four composting mixtures, 50kg termite mound and 2.5kg struvite with crop residues (stover of ground nut: 361.65kg; soybean: 354.59kg; potato: 357.67kg and mustard: 373.19kg) and cow dung (84.90kg) formed a good quality compost within 70days of composting having nitrogen, phosphorus and potassium as 21.59, 3.98 and 34.6gkg(-1), respectively. Multivariate analysis of variance revealed significant differences among the composts. The four composts formed two (pit 1, pit 2 and pit 3, pit 4) different groups. Two principal components expressed more than 97% of the total variability. Hierarchical cluster analysis resulted two homogeneous groups of composts. PMID:25836374

  15. Composting of cow dung and crop residues using termite mounds as bulking agent.

    PubMed

    Karak, Tanmoy; Sonar, Indira; Paul, Ranjit K; Das, Sampa; Boruah, R K; Dutta, Amrit K; Das, Dilip K

    2014-10-01

    The present study reports the suitability of termite mounds as a bulking agent for composting with crop residues and cow dung in pit method. Use of 50 kg termite mound with the crop residues (stover of ground nut: 361.65 kg; soybean: 354.59 kg; potato: 357.67 kg and mustard: 373.19 kg) and cow dung (84.90 kg) formed a good quality compost within 70 days of composting having nitrogen, phosphorus and potassium as 20.19, 3.78 and 32.77 g kg(-1) respectively with a bulk density of 0.85 g cm(-3). Other physico-chemical and germination parameters of the compost were within Indian standard, which had been confirmed by the application of multivariate analysis of variance and multivariate contrast analysis. Principal component analysis was applied in order to gain insight into the characteristic variables. Four composting treatments formed two different groups when hierarchical cluster analysis was applied. PMID:25108475

  16. The role of fire on soil mounds and surface roughness in the Mojave Desert

    USGS Publications Warehouse

    Soulard, Christopher E.; Esque, Todd C.; Bedford, David R.; Bond, Sandra

    2013-01-01

    A fundamental question in arid land management centers on understanding the long-term effects of fire on desert ecosystems. To assess the effects of fire on surface topography, soil roughness, and vegetation, we used terrestrial (ground-based) LiDAR to quantify the differences between burned and unburned surfaces by creating a series of high-resolution vegetation structure and bare-earth surface models for six sample plots in the Grand Canyon-Parashant National Monument, Arizona. We find that 11 years following prescribed burns, mound volumes, plant heights, and soil-surface roughness were significantly lower on burned relative to unburned plots. Results also suggest a linkage between vegetation and soil mounds, either through accretion or erosion mechanisms such as wind and/or water erosion. The biogeomorphic implications of fire-induced changes are significant. Reduced plant cover and altered soil surfaces from fire likely influence seed residence times, inhibit seed germination and plant establishment, and affect other ecohydrological processes.

  17. Mound-ACT*DE*CON{sup SM} feasibility study. Phase 2: Final report

    SciTech Connect

    1994-12-01

    A portion of the abandoned Miami-Erie Canal paralleling the Greater Miami River receives the runoff and storm-water discharge from Mound Laboratory. In 1969, a low-level plutonium leak contaminated sediment as far away as 1.5 mi from the Mound site along the old canal system. An estimated one million cubic feet of sediment requires remediation. The technology being evaluated for the remediation of the low-level plutonium-238 contamination of the sediment involves two processes: washing the sediments with ACT*DE*CON{sup SM} solution to dissolve the contaminant, followed by extraction of the solution and processing with the MAG*SEP{sup SM} process to concentrate the contaminant and allow reuse of the ACT*DE*CON{sup SM} solution. The processes are being optimized for pilot-scale and field demonstration. Phase 2 of the project primarily involved identification at the laboratory scale of the optimal ACT*DE*CON{sup SM} formulation, identification of the ion-exchanger and MAG*SEP{sup SM} particles, verification of the plutonium mobility in the treated soil, and evaluation of other process parameters according to a series of tasks.

  18. Focused risk assessment: Mound Plant, Miami-Erie Canal Operable Unit 4

    SciTech Connect

    Rogers, D.R.; Dunning, D.F.

    1994-09-29

    In 1969, an underground waste line at Mound Plant ruptured and released plutonium-238 in a dilute nitric acid solution to the surrounding soils. Most of the acid was neutralized by the native soils. The plutonium, which in a neutral solution is tightly sorbed onto clay particles, remained within the spill area. During remediation, a severe storm eroded some of the contaminated soil. Fine grained plutonium-contaminated clay particles were carried away through the natural drainage courses to the remnants of the Miami-Erie Canal adjacent to Mound Plant, and then into the Great Miami River. This focused risk assessment considers exposure pathways relevant to site conditions, including incidental ingestion of contaminated soils, ingestion of drinking water and fish, and inhalation of resuspended soils and sediments. For each potential exposure pathway, a simplified conceptual model and exposure scenarios have been used to develop conservative estimates of potential radiation dose equivalents and health risks. The conservatism of the dose and risk estimates provides a substantive margin of safety in assuring that the public health is protected.

  19. Diversity And Abundance Of Deep-Water Coral Mounds In The Straits Of Florida: A Result of Adaptability To Local Environments?

    NASA Astrophysics Data System (ADS)

    Correa, T. B.; Grasmueck, M.; Eberli, G.; Viggiano, D. A.; Rosenberg, A.; Reed, J. K.

    2007-12-01

    To improve the understanding of the Florida-Bahamas deep-water coral mound ecosystem, Autonomous Underwater Vehicle (AUV) surveys were conducted on five coral mound fields throughout the Straits of Florida (three sites at the base of slope of Great Bahama Bank (GBB), one in the middle of the Straits (MS) and one at the base of the Miami Terrace (MT)) in water depths of 590 to 860 m. The AUV provides high-resolution bathymetric maps, sub-bottom profiles and oceanographic data. The AUV survey sites were subsequently groundtruthed via sample collection and video transects, using the Johnson Sealink submersible. Contrary to previous surveys, we found a high diversity in coral mound morphology between sites separated by 15 to 80 km. The MT site is characterized by sinusoidal coral mound ridges, while the MS site contains densely clustered small coral mounds. Meanwhile, mounds of the GBB region are better developed, with some individual mounds reaching up to 90 m in height. Benthic coverage of live corals also differs between sites; the GBB sites are characterized by mounds densely covered by large thickets of live corals, while small thickets of mostly dead corals dominate the MT and MS sites. Several environmental factors may explain these differences. For example, bottom current patterns change between sites. The MT and the MS sites have a unidirectional regime (southward or northward flow, respectively), whereas the GBB sites have a tidal current regime. Sedimentation patterns as depicted by sub-bottom profiles also vary between the sites; coral mounds in the GBB area appear to receive higher sediment input, which can significantly enhance mound growth rates as the reef framework baffles and traps mobile sediments. However, coral mounds that cannot keep-up with the sedimentation rate are buried. Therefore, in the high sedimentation areas of GBB, flourishing live coral mounds are limited to elevated positions (i.e. plateaus, ridges crests) where sediment accumulation

  20. A biodetrital coral mound complex: Key to early diagenetic processes in the mississippian bangor limestone

    USGS Publications Warehouse

    Haywick, D.W.; Kopaska-Merkel, D. C.; Bersch, M.G.

    2009-01-01

    The Bangor Limestone is a Mississippian (Chesterian) shallow marine carbonate formation exposed over a large portion of the Interior Low Plateaus province of northern Alabama. It is dominated by oolitic grainstone and skeletal wackestone and packstone, but in one outcrop near Moulton, Alabama, the Bangor contains a five m thick, 25 m wide, oolitebiodetrital moundtidal flat succession. This sequence is interpreted as a 4th order sea level cycle. Four petrofacies (oolite, mound, skeletal and mudstone/dolomicrite) and four diagenetic phases (iron oxide, fibrous calcite cement, calcite spar cement and dolomite) are distinguished at the study site. Iron oxide, a minor component, stained and/or coated some ooids, intraclasts and skeletal components in the oolite petrofacies. Many of the allochems were stained prior to secondary cortical growth suggesting a short period of subaerial exposure during oolite sedimentation. The oolite petrofacies also contains minor amounts of fibrous calcite cement, a first generation marine cement, and rare infiltrated micrite that might represent a second phase of marine cement, or a first phase of meteoric cement (i.e., "vadose silt") (Dunham 1969). Intergranular pore space in all four petrofacies is filled with up to three phases of meteoric calcite spar cement. The most complete record of meteoric cementation is preserved within coralline void spaces in the mound petrofacies and indicates precipitation in the following order: (1) non-ferroan scalenohedral spar, (2) ferroan drusy spar (0.1-0.4 wt% Fe2+) and (3) non-ferroan drusy spar. The first scalenohedral phase of meteoric cement is distributed throughout the oolite and mound petrofacies. The ferroan phase of meteoric calcite is a void-filling cement that is abundant in the mound petrofacies and less common in the skeletal and mudstone/dolomicrite petrofacies. Non-ferroan drusy calcite is pervasive throughout the Bangor Limestone at the Moulton study site. Growth of the fourth

  1. The development of cold-water coral mounds along the Moroccan Atlantic and Mediterranean margins revealed by MeBo drillings

    NASA Astrophysics Data System (ADS)

    Hebbeln, Dierk; Wienberg, Claudia; Frank, Norbert

    2015-04-01

    Cold-water corals (CWC) mostly occur in intermediate water depths between 200 m and 1000 m and are capable of forming substantial seafloor structures, so-called coral carbonate mounds. These mounds can reach heights from a few meters up to >300 m and are composed of a mixture of CWC (and other shell) fragments and hemipelagic sediments, that both individually serve as distinct paleo-archives. IODP Leg 307 drilled through Challenger Mound at the Irish margin and revealed for the first time the full life history of a coral mound. However, although CWC occur almost worldwide, the 155 m long Challenger Mound record was for many years the only record from a coral mound exceeding 10 m in length. During expedition MSM36 with the German R/V MARIA S. MERIAN in spring 2014, several coral mounds along the Moroccan margin, both in the Atlantic Ocean and in the Mediterranean Sea, were drilled (actually: push-cored) by applying the Bremen Seafloor Drill Rig MeBo. The MeBo is a remotely controlled drilling system that is lowered from the vessel to the seafloor. Energy supply and video control are secured by an umbilical linking the MeBo to the vessel. The scientific foci of expedition MSM36 were to investigate (1) the long-term development of CWC mounds in both areas over the last several 100,000 years in relation to changes in the ambient environmental conditions in the respective intermediate waters, (2) the life time history of these mounds, and (3) the forcing factors for the initiation and decease of individual mounds. In both working areas, a total amount of 11 sites were successfully drilled with MeBo. Eight drillings were conducted at CWC mounds (on-mound sites) and 3 drillings in the direct vicinity of the mounds (off-mound sites) in order to obtain continuous paleoceanographic records. Drilling depths ranged between 17 m and 71 m with the latter corresponding to the maximum drilling depth of MeBo. The core recoveries varied between the sites and ranged between 47% and

  2. 77 FR 59615 - Decision To Evaluate a Petition To Designate a Class of Employees From the Mound Plant in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-28

    ... and/or Job Duties: All workers potentially exposed to radioactive materials while working at the Mound... Compensation Analysis and Support, National Institute for Occupational Safety and Health, 4676 Columbia Parkway... email to DCAS@CDC.GOV . John Howard, Director, National Institute for Occupational Safety and...

  3. Geoarchaeology and aggradation around Kinet Höyük, an archaeological mound in the Eastern Mediterranean, Turkey

    NASA Astrophysics Data System (ADS)

    Beach, Timothy P.; Luzzadder-Beach, Sheryl

    2008-10-01

    We examined the alluvial history of the plain near Kinet Höyük, an archaeological mound (or Tell) with a sequence of six millennia of occupation on the southeast Mediterranean coast of Turkey, through 17 excavations over a 1000 m transect near the Mound. Excavations ranged from 2 to 6 m deep and up to 20 m across. This low gradient, alluvial plain shows significantly different rates and processes of near-Mound sedimentation, with one unit having nearly 4 m of Late Bronze Age habitation and flood deposits and another having 4 m of Hellenistic channel and floodplain deposition. This flat, alluvial surface turns out to be a rich geoarchaeological landscape that shrouds Early and Late Bronze Age settlements, Hellenistic walls, and two epochs of Roman Roads. One widespread phenomenon was a Hellenistic or earlier paleosol and occupation level covered by channel gravels and overbank deposits mostly from the Hellenistic to the Late Roman period. These channel and floodplain deposits filled in and flattened out the off-Mound settlements, blanketing the Pre-Hellenistic topography and silting in a long active port. This glut of alluvium correlates in time with drier conditions and the most intensive land uses in the watershed, where Roman and Hellenistic sites today are severely eroded.

  4. Mound morphology of the 2+1 -dimensional Wolf-Villain model caused by the step-edge diffusion effect

    NASA Astrophysics Data System (ADS)

    Xun, Zhipeng; Tang, Gang; Han, Kui; Xia, Hui; Hao, Dapeng; Chen, Yuling; Wen, Rongji

    2010-12-01

    The mound morphology of the 2+1-dimensional Wolf-Villain model is studied by numerical simulation. The diffusion rule of this model has an intrinsic mechanism, i.e., the step-edge diffusion, to create a local uphill particle current, which leads to the formation of the mound. In the simulation, a noise reduction technique is employed to enhance the local uphill particle current. Our results for the dynamic exponent 1/z and the roughness exponent α obtained from the surface width show a dependence on the strength of the step-edge diffusion. On the other hand, λ(t), which describes the separation of the mounds, grows as a function of time in a power-law form in the regime where the coalescence of mounds occurs, λ(t)˜tn, with n≈0.23-0.25 for a wide range of the deposition conditions under the step-edge diffusion effect. For m=1, a noise reduction factor of unity, the behavior of λ(t) in the saturated regime is also simulated. We find that the evolution behavior of λ(t) in the whole process can be described by the standard Family-Vicsek scaling.

  5. Seasonal Changes in Broadband Spectral Reflectance Characteristics of Imported Fire Ant (Hymenoptera: Formicidae) Mound Features in Turfgrass Agroecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive mound-building imported fire ants (Solenopsis spp.) disrupt soil quality and turfgrass nutrient management in sod production, recreational, and residential settings. Ground-based implementation of hyperspectral techniques in the detection and seasonal monitoring of imported fire ant col...

  6. Implementation of Hyperspectral Techniques in the Remote Detection of Imported Fire Ants Mounds (Hymenoptera: Formicidae) in Cultivated Turfgrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Safe, expedient, and cost-effective treatments of imported fire ant (IFA) infestations require technological developments that exploit the use of remotely-sensed contrasting features to detect cryptic mounds in heavily-managed turfgrass. Ground-based implementation of hyperspectral techniques in the...

  7. Estimating Heat Transfer from Grotto Mound, NEPTUNE Canada Cabled Observatory, Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Rona, P. A.; Bemis, K. G.; Xu, G.

    2012-12-01

    Heat flux is a fundamental property of a seafloor hydrothermal system that relates to magnitude of sub-seafloor heat source and biosphere conditions, to distribution and style of seafloor venting and benthic biota, to chemical flux, plume formation, and dispersal of biological matter in the water column. We are working to estimate heat flux from Grotto mound, the site of the NEPTUNE Canada Cabled Observatory in the Main Endeavour Field on the Juan de Fuca Ridge. The mound is formed of two sulfide edifices that lie between ~2190 and 2180 m isobaths: 1) an elliptical edifice with major NE-SW-trending axis ~30 m long and minor axis ~ 14 m wide (area ~ 330 m2); 2) a columnar edifice ~ 10 m in diameter and 10 m high (area ~80 m2) named the North Tower, situated across a narrow (~5 m wide) saddle (area ~40 m2) at the W end of the elliptical edifice. Several black smokers discharge relatively small plumes at the E end of the elliptical edifice. A cluster of vigorous black smokers discharge from the top of North Tower and merge to form a large plume. Patchy diffuse flow occurs in areas around all of the black smokers and in the saddle between the two edifices. We are in process of measuring heat flux from components of hydrothermal discharge on Grotto mound, as follows: 1) for smokers on the North Tower an integrated heat flux of 28-55 MW is calculated based on temperature measurements in the initial 20 m rise of the plume assuming that the highest temperatures measured are closest to those of the plume centerline ; 2) for smokers on the E end of the elliptical edifice based on measurements of flow rate from video and acoustic Doppler phase shift, video of vent diameters, and in situ temperature measurements; 3) for discharge from flanges on some chimneys based on video of flow and in situ temperature measurements; 4) for diffuse flow based on area measured by Acoustic Scintillation Thermography and direct measurements of temperature and flow rate. We are evaluating

  8. Cold-water coral carbonate mounds and associated habitats of the Chella Seamount (Alboran Sea - SW Mediterranean)

    NASA Astrophysics Data System (ADS)

    Lo Iacono, C.; Bartolomé, R.; Gràcia, E.; Monteys, X.; Perea, H.; Gori, A.; Event-Shelf Team

    2009-04-01

    This study focuses on the characterization of cold-water carbonate mounds and of the associated habitats detected and mapped in the Chella Seamount, off the Almeria Margin, along the eastern Alboran Sea (SW Mediterranean). The study has been carried out by means of an integrated geophysical dataset, comprising large-scale sidescan sonar (TOBI), high resolution swath-bathymetry, TOPAS and Sparker high-resolution seismics. The acoustic dataset has been ground-truthed by images from an ROV and a deep-towed video-camera. Carbonate mounds range from 10 to 60 m in height and from 150 to 250 m in width, typically displaying a sub-circular shape. They are found within a depth range of 80-400 m and generally occur along the structural ridges of the Chella Seamount. Some of the mounds are distributed NW-SE and N-S, coinciding with the orientation of the active fault lineations observed North and West of the study area. On the other hand, the orientation of some other mounds suggests that the presence of strong bottom currents and reduced sedimentary fluxes are environmental factors suitable for their development. The images obtained from video inspections have been key for the characterization of the benthic communities and abundance of the species identified along the mounds. Video stills suggest that most of the mounds are in a "sub-fossil" stage and are mainly composed of patchy distributed Madrepora oculata and Lophelia pertusa. Additionally, other environments have been detected, in which sponges, boulders, coarse sands and bedforms prevail. Wide and dense patches of gorgonian (Callogorgia verticillata) have been observed along the top of the Chella Seamount. The integration of different marine geophysical methods supported by ground-truthing calibrations, allowed to recognize in detail the structural, sedimentary and hydrodynamic constrains suitable for the development of cold-water coral carbonate mounds in the Chella Seamount and to recognize and map some of the

  9. Deep sourced mounds offshore Costa Rica: A mechanism for non-magmatic forearc recycling of oceanic crust ?

    NASA Astrophysics Data System (ADS)

    Moerz, T.; Brueckmann, W.; Kopf, A.; Kreiter, S.; Wallmann, K.; Suess, E.

    2003-04-01

    More than 30 small-scale mounds, resembling diapirs and/or mud volcanoes, were discovered and mapped by high resolution swath bathymetry off Costa Rica during the RV SONNE expeditions 144 and 163 expedition. Commonly, these mounds are nearly circular in shape, several 10s of meters high with an average diameter of several 100 meters and occur in water depths between 900 and 2000 m. Subsequently four such mounds off the Nicoya Peninsula (~1600 m ), and off Quepos (~1000 m) were sampled in detail by gravity-, piston-, and multi coring and video-guided grab sampling during Legs RV METEOR 54/2 and 54/3A.Overcompacted and tectonically deformed clays, fluid and mud channels (locally calcified), open hydrofractures, mineralized veins, various allochtonous fragments including mafic crystalline pebbles and hydrate layers where recovered at central mound locations. In contrast flank samples of these mounds are characterized by brecciated reworked authigenic carbonates, chaotic mud and debris flows, turbidite sequences and accumulations of clasts. In our ongoing work we use these characteristics and determine the sediment fabric using x-ray CT (computer tomography) in order to understand the role of fluids and solid phases in mound formation in the context of the erosional convergent margin development off Costa Rica. Critical with respect to the margin development and mound formation are reliable criteria for the source depth of the extruded material. So far the stress memory of clays derived from undrained shear strength gives a minimum source depth of >100 mbsf when compared to reference material from flanks and other slope sites. However, the recovered mafic crystalline clasts point to a much greater depth of at least 1500 mbsf for the source of solid phases and possibly fluids originating within the thin dewatered sediment wedge below the Costa Rica crystalline basement at ~7500 mbsf. Alternate source depth estimates from organic matter maturity indicators will

  10. Heat transfer through the sediments of the mounds hydrothermal area, Galapagos Spreading Center at 86 /sup 0/W

    SciTech Connect

    Becker, K.; Von Herzen, R.P.

    1983-02-10

    Heat transfer processes at the mounds area of the Galapagos Spreading Center at 86 /sup 0/W are revealed by temperatures measured at roughly-equal10-m intervals in the 30 +- 10 m sediment at each of 12 holes at DSDP Leg 70 Sites 506--509 and by temperatures of up to five thermistors on eleven 8--12 m long piston cores. The 325 needle-probe values show a significant linear increase of thermal conductivity with depth in each core. About half of the temperature-thermal resistance profiles are nonlinear and are fit to a steady state, vertical pore water advection model. Results indicate high and variable total heat flow and localized hydrothermal discharge at roughly-equal10/sup -8/ m/s, associated with individual mounds. Recharge is indicated at similar rates in the low heat flow belt roughly-equal5 km south of the mounds and is suggested at slower rates in the intermediate heat flow (0.17--0.42 W/m/sup 2/) belt surrounding the mounds heat flow high. Possible slow entrained recharge within roughly-equal100 m of discharging mounds is suggested. Also suggested is strong local discharge along the major fault bounding the mounds crustal block to the north. About 95 km north of the spreading axis, at DSDP Site 510, temperatures in the 114-m sediment cover on 2.7-m.y. crust are linear, consistent with the suggestion that the hydraulic resistance of this layer is sufficient to seal off free hydrothermal exchange between basement and bottom water. The combination of heat flow data and the physical properties data of Karato and Becker (this issue) suggests that roughly-equal50 m of sediment may be a threshold thickness for sealing of hydrothermal circulation within basement, where the topography is smooth. We suggest that the formation of mounds may be associated with the forced localization of hydrothermal discharge through the sediment, as its thickness approaches this threshold value.

  11. Formation of carbonate concretions in surface sediments of two mud mounds, offshore Costa Rica: a stable isotope study

    NASA Astrophysics Data System (ADS)

    Mavromatis, Vasileios; Botz, Reiner; Schmidt, Mark; Liebetrau, Volker; Hensen, Christian

    2014-10-01

    The surface sediments of two mud mounds ("Mound 11" and "Mound 12") offshore southwest Costa Rica contain abundant authigenic carbonate concretions dominated by high-Mg calcite (14-20 mol-% MgCO3). Pore fluid geochemical profiles (sulfate, sulfide, methane, alkalinity, Ca and Mg) indicate recent carbonate precipitation within the zone of anaerobic oxidation of methane (AOM) at variable depths. The current location of the authigenic carbonate concretions is, however, not related to the present location of the AOM zone, suggesting mineral precipitation under past geochemical conditions as well as changes in the flow rates of upward migrating fluids. Stable oxygen and carbon isotope analysis of authigenic carbonate concretions yielded δ18Ocarbonate values ranging between 34.0 and 37.7 ‰ Vienna standard mean ocean water (VSMOW) and δ13Ccarbonate values from -52.2 to -14.2 ‰ Vienna Pee Dee belemnite (VPDB). Assuming that no temperature changes occurred during mineral formation, the authigenic carbonate concretions have been formed at in situ temperature of 4-5 °C. The δ18Ocarbonate values suggest mineral formation from seawater-derived pore fluid (δ18Oporefluid = 0 ‰ VSMOW) for Mound 12 carbonate concretions but also the presence of an emanating diagenetic fluid (δ18Oporefluid ≈5 ‰) in Mound 11. A positive correlation between δ13Ccarbonate and δ18Ocarbonate is observed, indicating the admixing of two different sources of dissolved carbon and oxygen in the sediments of the two mounds. The carbon of these sources are (1) marine bicarbonate (δ13Cporefluid ≈0 ‰) and (2) bicarbonate which formed during the AOM (δ13Cporefluid ≈-70 ‰). Furthermore, the δ18Oporefluid composition, with values up to +4.7 ‰ Vienna standard mean ocean water (VSMOW), is interpreted to be affected by the presence of emanating, freshened and boron-enriched fluids. Earlier, it has been shown that the origin of 18O-enriched fluids are deep diagenetic processes as it was

  12. Geoarchaeological research on Bronze Age settlement mounds in the Kolkheti lowlands at the Black Sea coast of Georgia

    NASA Astrophysics Data System (ADS)

    Laermanns, Hannes; Heisterkamp, Arne; Kirkitadze, Giorgi; Elashvili, Mikheil; Verheul, Jan; Kelterbaum, Daniel; Helmut, Brückner

    2016-04-01

    0.0.1 Situated between the Rivers Enguri in the north and Khobistsqali in the south, more than 20 settlement mounds (local name Dikhagudzuba), identified by field survey and remote sensing techniques, give evidence of a densely populated landscape in the coastal lowlands of eastern Georgia during the Bronze Age. While the existing chronology of these mounds is based on ceramic evidence obtained during a previous archaeological research, only limited information is available on their internal architecture and their palaeoenvironmental context, and the chronology of the different layers is as yet lacking. 0.0.2 Within the framework of a geoarchaeological research project, we carried out eleven vibracores on and in direct vicinity of three of the most prominent mounds, situated close to the villages of Orulu and Ergeta. Based on these sediment cores, our study aims at (i) establishing a chronostratigraphical framework for the settlements based on radiocarbon dating; (ii) reconstructing possible phases and gaps of occupation; and (iii) identifying the environmental conditions during the time of their existence. Geochemical and sedimentological analyses were carried out to decipher element contents (XRF), granulometry, and organic contents (LOI, C/N) of sediment samples, supporting the interpretation of the mounds' stratigraphical evolution and related human occupation. The three investigated settlement mounds are similar in dimension and stratigraphy, and different settlement layers could be identified in each of them. The 14C age estimates indicate that their formation occurred during the second half of the 3rd and the first half of the 2nd millennium BC, thus confirming the archaeological interpretation of their Bronze Age origin. Based on the granulometric and geochemical data, palaeoenvironmental conditions in the vicinity of the settlements were dominated by fluvial processes.

  13. Shallow surface methane hydrate associated with mud diapir äMound 11`` in the Costa Rica fore arc zone

    NASA Astrophysics Data System (ADS)

    Schmidt, M.; Hensen, C.; Mörz, T.; Mau, S.; Grevemeyer, I.; Wallmann, K.; Sahling, H.; Brückmann, W.

    2003-04-01

    Gas hydrates were recovered from a mud diapir (Mound 11) located on the southern continental slope off Costa Rica at a water depth of about 1000 m during expedition M54/2 with RV METEOR in September 2002. A massive layer of solid methane gas hydrate was retrieved from the base of a gravity corer at a sediment depth of 2 m. Several mound-shaped and carbonate-covered mud diapirs were previously discovered off Costa Rica and Nicaragua during the ongoing research within the framework of the Sonderforschungsbereich 574 "Volatiles and Fluids in Subduction Zones" but solid hydrates were recovered only from Mound 11. This structure has a diameter of about 300 m and protrudes the surrounding seafloor by about 20 m. The seamount sits on approximately 1 km of hemipelagic sediment disrupted by normal faults, which could provide fluid and mass transport pathways from greater depth to the sea floor. Video observations of Mound 11 revealed the presence of authigenic carbonates and bacterial mats indicating methane-charged fluids reaching the sediment surface. Water sampling and gas chromatographic analyses showed methane enrichments in the overlying bottom water confirming the release of methane. In-situ temperature measurements indicated elevated heat flow within the hydrate-bearing sediment strata. Pore fluids recovered from the mound were strongly depleted in dissolved chloride and enriched in boron indicating a deep origin of rising fluids and gases. The results of the ongoing isotopic analysis of gas hydrates and pore waters will be used to further constrain the source of methane-rich fluids.

  14. Significance of botryoidal aragonite in early diagenetic history of phylloid algal mounds in Bug and Papoose Canyon fields, southeastern Utah and southwestern Colorado

    SciTech Connect

    Roylance, M.H.

    1984-04-01

    Abundant altered botryoidal aragonite cement is recognized both in core slabs and thin sections from phylloid algal-mound facies in the Desert Creek interval of the Paradox Formation in the Papoose Canyon-Bug field area. This subsequently dolomitized cement occurs as individual to coalescing botryoids, which appear in cross section as rounded feather-edge fans composed of radiating crystals. Botryoids locally comprise up to 90% of any given section of core. The botryoids are similar in appearance to Holocene botryoidal aragonite cement. However, it is deduced that, unlike modern counterparts, these botryoids grew both on the sea floor as well as within open cavities within the mound framework. The diagenetic history of the mounds in the Papoose Canyon-Bug field area was initiated with precipitation of botryoidal aragonite cement penecontemporaneously with deposition of phylloid algal plates, creating rigid anastomosing frameworks containing abundant primary porosity. When compacted, these mounds were brecciated, thus opening up more porosity. Some of the porosity was subsequently infilled by internal sediment and calcite and gypsum cements. Finally, these mounds were extensively dolomitized, and some secondary porosity was created by leaching. The fundamental significance of botryoidal aragonite at Papoose Canyon and Bug fields is that it helped to create and preserve very porous and permeable phylloid algal mounds by contributing to the formation of a rigid framework containing primary porosity, and by cementing the mounds early so that they became brecciated upon compaction. The preserved pores were ultimately filled with oil.

  15. Stromatactis—Origin related to submarine-cemented crusts in Paleozoic mud mounds

    NASA Astrophysics Data System (ADS)

    Bathurst, Robin G. C.

    1980-03-01

    Stromatactis, long familiar as reticulate masses of sparry calcite in Paleozoic mud mounds and more recently identified as a system of cement-filled cavities, has been studied in limestones of Ordovician age in Sweden, of Devonian age in Australia, and of Carboniferous age in England. The origin of the cavity system has been uncertain. However, many features suggest a linking of its origin to cementation of a succession of submarine crusts and the development of cavities in the intercalated, less-cemented carbonate muds. Examination of the morphology of the sediment layers between the masses of spar reveals a similarity with thin brittle sheets or crusts alternating with incoherent mud—a situation perhaps not unlike that seen today on lithoherms in the Straits of Florida.

  16. An overview of plutonium-238 decontamination and decommissioning (D and D) projects at Mound

    SciTech Connect

    Bond, W.H.; Davis, W.P.; Draper, D.G.; Geichman, J.R.; Harris, J.C.; Jaeger, R.R.; Sohn, R.L.

    1987-01-01

    Mound is currently decontaminating for restricted reuse and/or decommissioning for conditional release four major plutonium-238 contaminated facilities that contained 1700 linear feet of gloveboxes and associated equipment and services. Several thousand linear feet of external underground piping, associated tanks, and contaminated soil are being removed. Two of the facilities contain ongoing operations and will be reused for both radioactive and nonradioactive programs. Two others will be completely demolished and the land area will become available for future DOE building sites. An overview of the successful techniques and equipment used in the decontamination and decommissioning of individual pieces of equipment, gloveboxes, services, laboratories, sections of buildings, entire buildings, and external underground piping, tanks, and soil in a highly populated residential area is described and pictorially presented.

  17. The hill forts and castle mounds in Lithuania: interaction between geodiversity and human-shaped landscape

    NASA Astrophysics Data System (ADS)

    Skridlaite, Grazina; Guobyte, Rimante; Satkunas, Jonas

    2015-04-01

    Lithuania is famous for its abundant, picturesque hill forts and castle mounds of natural origin. In Lithuania as well as in whole Europe the fortified hills were used as the society dwelling place since the beginning of the Late Bronze Age. Their importance increased when Livonian and Teutonic Orders directed a series of military campaigns against Lithuania with the aim of expansion of Christianity in the region at the end of 1st millennium AD, and they were intensively used till the beginning of the 15th c. when most of them were burned down during fights with the Orders or just abandoned due to the changing political and economical situation. What types of the geodiversity were used for fortified dwellings? The choice in a particular area depended on a variety of geomorphology left behind the retreating ice sheets. High spots dominating their surroundings were of prime interest. In E and SE Lithuania, the Baltic Upland hills marking the eastern margin of the last Weichselian glacier hosted numerous fortified settlements from the end of 2nd millennium BC to the Medieval Ages (Narkunai, Velikuskes etc). In W Lithuania, plateau-like hills of the insular Samogitian Upland had been repeatedly fortified from the beginning of 1st millennium AD to the 14th century (Satrija, Medvegalis etc). Chains of hill forts and castle mounds feature the slopes of glaciofluvial valleys of Nemunas, Neris and other rivers where the slopes were dissected by affluent rivulets and ravines and transformed into isolated, well protected hills (Kernave, Punia, Veliuona etc). Peninsulas and headlands formed by the erosion of fluvial and lacustrine deposits were used in the lowlands, e.g. in central and N Lithuania (Paberze, Mezotne etc). How much the landscape was modified for defense purposes? Long-term erosion and overgrowing vegetation damaged the former fortified sites, however some remains and the archeological excavations allowed their reconstruction. The fortified Bronze Age settlements

  18. Ecological feedbacks. Termite mounds can increase the robustness of dryland ecosystems to climatic change.

    PubMed

    Bonachela, Juan A; Pringle, Robert M; Sheffer, Efrat; Coverdale, Tyler C; Guyton, Jennifer A; Caylor, Kelly K; Levin, Simon A; Tarnita, Corina E

    2015-02-01

    Self-organized spatial vegetation patterning is widespread and has been described using models of scale-dependent feedback between plants and water on homogeneous substrates. As rainfall decreases, these models yield a characteristic sequence of patterns with increasingly sparse vegetation, followed by sudden collapse to desert. Thus, the final, spot-like pattern may provide early warning for such catastrophic shifts. In many arid ecosystems, however, termite nests impart substrate heterogeneity by altering soil properties, thereby enhancing plant growth. We show that termite-induced heterogeneity interacts with scale-dependent feedbacks to produce vegetation patterns at different spatial grains. Although the coarse-grained patterning resembles that created by scale-dependent feedback alone, it does not indicate imminent desertification. Rather, mound-field landscapes are more robust to aridity, suggesting that termites may help stabilize ecosystems under global change. PMID:25657247

  19. Characterization of magnetic material in the mound-building termite Macrotermes gilvus in Southeast Asia

    SciTech Connect

    Esa, Mohammad Faris Mohammad; Hassan, Ibrahim Haji; Rahim, Faszly; Hanifah, Sharina Abu

    2015-09-25

    Magnetic material such as magnetite are known as particles that respond to external magnetic field with their ferromagnetic properties as they are believed contribute to in responding to the geomagnetic field. These particles are used by terrestrial animals such as termites for navigation and orientation. Since our earth react as giant magnetic bar, the magnitude of this magnetic field present by intensity and direction (inclination and direction). The magnetic properties and presence of magnetite in termites Macrotermes gilvus, common mound-building termite were tested. M. gilvus termites was tested with a Vibrating Sample Magnetometer VSM to determine the magnetic properties of specimen. The crushed body sample was characterized with X-Ray Diffraction XRD to show the existent of magnetic material (magnetite) in the specimens. Results from VSM indicate that M. gilvus has diamagnetism properties. The characterization by XRD shows the existent of magnetic material in our specimen in low concentration.

  20. Kinetic Monte Carlo Simulation of Epitaxial Thin Film Growth: Formation of Submonolayer Islands and Multilayer Mounds

    SciTech Connect

    Evans, J. W.; Thiel, P. A.; Li, Maozhi

    2007-06-14

    We consider homoepitaxy (or low-misfit heteroepitaxy) via vapor deposition or MBE under UHV conditions. Thin film growth is initiated by nucleation and growth of 2D islands in the submonolayer regime. For atoms subsequently deposited on top of islands, a step edge barrier often inhibits downward transport and produces kinetic roughening during multilayer growth. Such unstable growth is characterized by the formation of 3D mounds (multilayer stacks of 2D islands). Kinetic Monte Carlo (KMC) simulation of suitable atomistic lattice-gas models can address fundamental or general issues related to both submonolayer and multilayer film evolution, and can also provide a predictive tool for morphological evolution in specific systems. Examples of the successes of KMC modeling are provided for metal homoepitaxial film growth, specifically for contrasting behavior in the classic Ag/Ag(100) and Ag/Ag(111) systems.

  1. Short-billed dowitchers crowd a grassy mound in the waters around KSC

    NASA Technical Reports Server (NTRS)

    1999-01-01

    A flock of short-billed dowitchers crowd onto a grassy mound in the shallow waters of the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. The dowitchers range from southern Alaska to eastern Canada, and they winter from the southern United States to central South America. They often frequent coastal flats during migrations. The 92,000- acre refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

  2. Characterization of magnetic material in the mound-building termite Macrotermes gilvus in Southeast Asia

    NASA Astrophysics Data System (ADS)

    Esa, Mohammad Faris Mohammad; Rahim, Faszly; Hassan, Ibrahim Haji; Hanifah, Sharina Abu

    2015-09-01

    Magnetic material such as magnetite are known as particles that respond to external magnetic field with their ferromagnetic properties as they are believed contribute to in responding to the geomagnetic field. These particles are used by terrestrial animals such as termites for navigation and orientation. Since our earth react as giant magnetic bar, the magnitude of this magnetic field present by intensity and direction (inclination and direction). The magnetic properties and presence of magnetite in termites Macrotermes gilvus, common mound-building termite were tested. M. gilvus termites was tested with a Vibrating Sample Magnetometer VSM to determine the magnetic properties of specimen. The crushed body sample was characterized with X-Ray Diffraction XRD to show the existent of magnetic material (magnetite) in the specimens. Results from VSM indicate that M. gilvus has diamagnetism properties. The characterization by XRD shows the existent of magnetic material in our specimen in low concentration.

  3. A radioactive waste excavation at Mound Area 7 using INEL dig-face monitoring technology

    SciTech Connect

    Carpenter, M.V.; Josten, N.E.

    1996-12-31

    Dig-face characterization is a method to improve the safety and efficiency during hazardous waste retrieval. A dig-face characterization system consists of on-site hardware for collecting detailed information on the changing chemical, radiological, and physical conditions in the subsurface throughout a hazardous site excavation. The dig-face characterization concept originated at the Idaho National Engineering Laboratory where it has been under development since 1992. In August 1995, a prototype dig-face system was taken to Mound Laboratory, Ohio, to monitor a hazardous waste site excavation. Mound Area 7 was the site of previous disposal of {sup 232}Th, {sup 227}Ac, and other waste. The dig-face characterization system was used to monitor a 20-ft x 20-ft x 5-ft-deep excavation intended to remove the {sup 227}Ac contaminated soils. Radiological, geophysical, and topographical sensors were scanned across each of four successive excavated soil levels, each 1-ft to 2-ft thick. The radiation sensors produced highly detailed images showing the location of the contaminants {sup 232}Th and {sup 227}Ac, and the clear delineation between them. When combined into a single data set, the four levels of collected data produced a three dimensional image of the contamination. The radiation sensor data indicated that only a small portion of the excavated soil was actually contaminated. The information produced by the dig-face system was used to direct precise excavation activities in the area containing the {sup 227}Ac and to plan subsequent removal of the separate {sup 232}Th plume.

  4. Geophysical Investigations of the Mound City Borrow Pits, Ross County, Ohio

    NASA Astrophysics Data System (ADS)

    Benson, Blair Elizabeth

    Geophysical subsurface imaging is becoming a common practice in archaeology. Non-invasive geophysical methods provide efficient alternatives to costly and invasive excavations, allowing archaeologists to analyze sites before any excavation is done to identify areas of interest. For my thesis, I investigated two prehistoric borrow pits at the Mound City Group (200 BC - 200 AD) in the Hopewell Culture National Historical Park in south-central Ohio. The primary objective of this study was to determine the presence and spatial extent of a clay lining that was emplaced upon the borrow pits by the Hopewell people. Information gleaned from the geophysical investigation was used to assess the degree of site disturbance from agriculture, construction of Camp Sherman, and modern reconstruction of the earthworks. My analysis included a suite of overlapping geophysical surveys consisting of ground-penetrating radar, magnetometry, electromagnetic induction, and electrical resistivity. The geophysical data was ground-truthed with limited auguring and trenching. Analysis of the first borrow pit data showed strong evidence of historical disturbance within the pit from construction of Camp Sherman, including disturbed soil and a buried utility pipe, leaving little of the clay lining present except around the edges of the borrow pit. The geophysical data for the second borrow pit showed less historical damage that was primarily caused from the re-excavation of the pit during the reconstruction of the park. The second borrow pit still retains about half of the clay lining, a finding supported by the results of auguring and trenching. These results are evidence that the borrow pits at Mound City may have also served a purpose as cultural landscape features. The geophysical methods used in this study proved to be an invaluable source of information with minimal disturbance of the site.

  5. Strategic Petroleum Reserve (SPR) additional geologic site characterization studies, Bryan Mound Salt Dome, Texas

    SciTech Connect

    Neal, J.T.; Magorian, T.R.; Ahmad, S.

    1994-11-01

    This report revises the original report that was published in 1980. Some of the topics covered in the earlier report were provisional and it is now practicable to reexamine them using new or revised geotechnical data and that obtained from SPR cavern operations, which involves 16 new caverns. Revised structure maps and sections show interpretative differences as compared with the 1980 report and more definition in the dome shape and caprock structural contours, especially a major southeast-northwest trending anomalous zone. The original interpretation was of westward tilt of the dome, this revision shows a tilt to the southeast, consistent with other gravity and seismic data. This interpretation refines the evaluation of additional cavern space, by adding more salt buffer and allowing several more caverns. Additional storage space is constrained on this nearly full dome because of low-lying peripheral wetlands, but 60 MMBBL or more of additional volume could be gained in six or more new caverns. Subsidence values at Bryan Mound are among the lowest in the SPR system, averaging about 11 mm/yr (0.4 in/yr), but measurement and interpretation issues persist, as observed values are about the same as survey measurement accuracy. Periodic flooding is a continuing threat because of the coastal proximity and because peripheral portions of the site are at elevations less than 15 ft. This threat may increase slightly as future subsidence lowers the surface, but the amount is apt to be small. Caprock integrity may be affected by structural features, especially the faulting associated with anomalous zones. Injection wells have not been used extensively at Bryan Mound, but could be a practicable solution to future brine disposal needs. Environmental issues center on the areas of low elevation that are below 15 feet above mean sea level: the coastal proximity and lowland environment combined with the potential for flooding create conditions that require continuing surveillance.

  6. Critiques of the seismic hypothesis and the vegetation stabilization hypothesis for the formation of Mima mounds along the western coast of the U.S.

    NASA Astrophysics Data System (ADS)

    Gabet, Emmanuel J.; Burnham, Jennifer L. Horwath; Perron, J. Taylor

    2016-09-01

    A recent paper published in Geomorphology by Gabet et al. (2014) presents the results of a numerical model supporting the hypothesis that burrowing mammals build Mima mounds - small, densely packed hillocks found primarily in the western United States. The model is based on field observations and produces realistic-looking mounds with spatial distributions similar to real moundfields. Alternative explanations have been proposed for these Mima mounds, including formation by seismic shaking and vegetation-controlled erosion and deposition. In this short communication, we present observations from moundfields in the coastal states of the western U.S. that are incompatible with these alternative theories.

  7. Integrated electromagnetic methods for archaeological prospection and stability assessment of anthropogenic mounds: insights into the English Cemetery in Florence

    NASA Astrophysics Data System (ADS)

    Cappuccini, Luca; Pazzi, Veronica; Tapete, Deodato

    2013-04-01

    The archaeological interest in anthropogenic mounds as historical products of human occupation generally concerns the understanding of their stratigraphic sequence and the discovery of buried structures. Nevertheless, a further key element relies on the assessment of their stability. This is particularly crucial when the conservation history induced relevant alteration of the former configuration, and a potential collapse might cause damages to heritage and actual risk for public safety. To respond to such dual diagnostic need, we propose an integration approach based on Very Low Frequency Electromagnetic (VLF-EM) qualitative method and 2D-Electrical Resistivity Tomography (2D-ERT), to make the best out of these two techniques in light of their frequencies/bandwidth and methods of soil investigation (15-30 kHz and DC, respectively). We present here the results from the experiments performed on one of the test sites selected to validate the proposed methodology, i.e. the Protestant Cemetery (the so-called "English Cemetery") in Florence, Italy, which is a demonstrative example of a huge sample of anthropogenic mounds within urban and rural environments. Located on a topographic relief, the cemetery testifies a long history since Roman times, as proved by historical documentation and the ceramic findings still now discovered on the (sub-)surface. Converted into a cemetery in 1827, the mound appeared as an anomalous outcrop adjacent to the town walls, prior to the final arrangement and reshaping due to the urban renewal of Florence in 1877, which definitely transformed it into a raised graveyard surrounded by boulevards. A campaign of VLF-EM and ERT measurements was performed to ascertain the presence of a buried part of the ancient eastern wall and identify the key areas of concern for the stability. High values of resistivity were clearly detected and mapped by means of 2D-ERT along the AA' array intercepting the hypothesized location of the buried wall. This

  8. Geologic investigation of layered mound of Henry Crater, Mars: Implications for history of ancient hydrological activities in the region

    NASA Astrophysics Data System (ADS)

    Sarkar, Samarpita; Sinha, Rishitosh Kumar; Banerjee, Debabrata; Vijayan, S.

    2016-07-01

    Craters around the Schiaparelli Basin (sim460 km diameter; 2.71^circS 16.77^circE) on Mars are distributed in a unique combination that includes infilled craters with mound on their floors. The mounds have preserved intriguing layers in stratigraphy that has exposed pristine sets of geomorphic and geochemical signatures bearing strong implications towards understanding geological history of Mars. With a view to avail the maximum scientific benefit from this unique geological assemblage on Mars, we have carried out remote analysis of stratigraphy of layers exposed over Henry crater's (sim150 km diameter; 10.79^circN 23.45^circE) mound (rising sim2km from floor) to infer the origin and episodes of geological events occurred in the region. Henry crater is situated approximately 500 km northeast of Schiaparelli Basin. Using crater counting technique the age of the topmost surface of the crater mound is found to be sim3.64 Ga since the exposure of this strata post complete infilling. The stratigraphy of consistent and conformable layers in the crater interior acts as a proxy of the long-lived event of sediment deposition in a rather quiescent condition. Distinct layering can be traced across the crater from the mound to the crater wall across the floor. Evidence for differential erosion of deposited materials, wherein local geological setup developed in the different parts of the crater interior is preserved. Using MRO HiRISE & CTX images, distinct spatial distribution of morphological features distributed in stratigraphy is observed that reveals the dominant geological agents behind their formation, viz. temporal hydrological and eolian processes. The morphological features were aided with an understanding of the composition of the exposed sedimentary succession. MRO CRISM based mineralogical investigation reveals diagnostic signature of the hydrated sulfate mineral Kieserite. Based on the thermodynamic properties of Kieserite and apparent lack of desiccation cracks in

  9. Middle Miocene mound-shaped sediment packages on the slope of the Xisha carbonate platforms, South China Sea: Combined result of gravity flow and bottom current

    NASA Astrophysics Data System (ADS)

    Tian, Jie; Wu, Shiguo; Lv, Fuliang; Wang, Dawei; Wang, Bin; Zhang, Xinyuan; Ma, Benjun

    2015-12-01

    Deep-water mound-shaped sediment packages on the northern slope of the Xisha carbonate platforms in the northern South China Sea were analyzed by integrating high-resolution multi-channel seismic and drilling data. The mounds are distributed in the Beijiao depression of the Qiongdongnan Basin within the T41-T40 seismic horizons, which correspond to the middle Miocene. Mound-shaped reflections were identified both in the NE-SW and NW-SE oriented seismic profiles. The mound shapes are most prominent in the center of the NW-SE oriented seismic profiles, and the undulating tops flatten out towards the NW and SE. Similar reflections are mostly asymmetric, with steeper eastern flanks in the NE-SW oriented seismic profiles, and they are mostly round in shape. The wave impedance from the inversion calculation is 6-8×106 kg/(m2·s). It is much lower than that of the reef reservoir in the LH11-1 Reef Oilfield. Paleogeographic analysis shows that the Xisha uplift was dominated by tropical shallow carbonate platforms, while the Beijiao depression became a bathyal environment in the middle Miocene. Drilling data confirmed that the mound-shaped sediment packages are mainly composed of calcareous mudstone. Therefore, we infer that the mound-shaped sediment packages could be reef complexes or they were presumably built by combined gravity flow and bottom current.

  10. Depositional and diagenetic history of a Pennsylvanian algal-mound complex: Bug and Papoose Canyon fields, Paradox basin, Utah and Colorado

    SciTech Connect

    Roylance, M.H.

    1990-07-01

    During the Middle Pennsylvanian (Desmoinesian), the Paradox basin was an enclosed, evaporitic basin consisting of a deep trough with a shallow shelf rimming its south and west side. During Desert Creek deposition, at least two large phylloid algal-mound complexes flourished on or at the edge of the shelf. One complex is now delineated by Aneth field and the other is partly delineated by Bug and Papoose Canyon fields. In the Bug-Papoose Canyon algal-mound complex of southeastern Utah and southwestern Colorado, carbonate mud mounds grew by accumulation of platy algal fragments, by baffling and trapping of fine sediment by the algae, and by precipitation of botryoidal aragonite cement between fragments. Extensive diagenesis of the accumulations began with syndepositional precipitation of botryoidal cement, inferred to have been aragonite, on phylloid algal plates, creating a topographically prominent, rigid framework containing abundant pore space. Brecciation during compaction created more pores. Parts of voids were subsequently filled by internal sediment and by calcite and gypsum cements. Finally, the algal-mound accumulations were extensively dolomitized and their porosity increased by dissolution. The relationship of these algal mounds to the Desert Creek shelf edge suggests that delineation of the shelf edge holds the promise of further discoveries of algal mounds as it is traced to the west and east of Bug and Papoose Canyon fields. 17 figs., 1 tab.

  11. Microfossils, a Key to Unravel Cold-Water Carbonate Mound Evolution through Time: Evidence from the Eastern Alboran Sea.

    PubMed

    Stalder, Claudio; Vertino, Agostina; Rosso, Antonietta; Rüggeberg, Andres; Pirkenseer, Claudius; Spangenberg, Jorge E; Spezzaferri, Silvia; Camozzi, Osvaldo; Rappo, Sacha; Hajdas, Irka

    2015-01-01

    Cold-water coral (CWC) ecosystems occur worldwide and play a major role in the ocean's carbonate budget and atmospheric CO2 balance since the Danian (~65 m.y. ago). However their temporal and spatial evolution against climatic and oceanographic variability is still unclear. For the first time, we combine the main macrofaunal components of a sediment core from a CWC mound of the Melilla Mounds Field in the Eastern Alboran Sea with the associated microfauna and we highlight the importance of foraminifera and ostracods as indicators of CWC mound evolution in the paleorecord. Abundances of macrofauna along the core reveal alternating periods dominated by distinct CWC taxa (mostly Lophelia pertusa, Madrepora oculata) that correspond to major shifts in foraminiferal and ostracod assemblages. The period dominated by M. oculata coincides with a period characterized by increased export of refractory organic matter to the seafloor and rather unstable oceanographic conditions at the benthic boundary layer with periodically decreased water energy and oxygenation, variable bottom water temperature/density and increased sediment flow. The microfaunal and geochemical data strongly suggest that M. oculata and in particular Dendrophylliidae show a higher tolerance to environmental changes than L. pertusa. Finally, we show evidence for sustained CWC growth during the Alleröd-Younger-Dryas in the Eastern Alboran Sea and that this period corresponds to stable benthic conditions with cold/dense and well oxygenated bottom waters, high fluxes of labile organic matter and relatively strong bottom currents. PMID:26447699

  12. Microfossils, a Key to Unravel Cold-Water Carbonate Mound Evolution through Time: Evidence from the Eastern Alboran Sea

    PubMed Central

    Stalder, Claudio; Vertino, Agostina; Rosso, Antonietta; Rüggeberg, Andres; Pirkenseer, Claudius; Spangenberg, Jorge E.; Spezzaferri, Silvia; Camozzi, Osvaldo; Rappo, Sacha; Hajdas, Irka

    2015-01-01

    Cold-water coral (CWC) ecosystems occur worldwide and play a major role in the ocean's carbonate budget and atmospheric CO2 balance since the Danian (~65 m.y. ago). However their temporal and spatial evolution against climatic and oceanographic variability is still unclear. For the first time, we combine the main macrofaunal components of a sediment core from a CWC mound of the Melilla Mounds Field in the Eastern Alboran Sea with the associated microfauna and we highlight the importance of foraminifera and ostracods as indicators of CWC mound evolution in the paleorecord. Abundances of macrofauna along the core reveal alternating periods dominated by distinct CWC taxa (mostly Lophelia pertusa, Madrepora oculata) that correspond to major shifts in foraminiferal and ostracod assemblages. The period dominated by M. oculata coincides with a period characterized by increased export of refractory organic matter to the seafloor and rather unstable oceanographic conditions at the benthic boundary layer with periodically decreased water energy and oxygenation, variable bottom water temperature/density and increased sediment flow. The microfaunal and geochemical data strongly suggest that M. oculata and in particular Dendrophylliidae show a higher tolerance to environmental changes than L. pertusa. Finally, we show evidence for sustained CWC growth during the Alleröd-Younger-Dryas in the Eastern Alboran Sea and that this period corresponds to stable benthic conditions with cold/dense and well oxygenated bottom waters, high fluxes of labile organic matter and relatively strong bottom currents PMID:26447699

  13. Combining ER and GPR surveys for evidence of prehistoric landscape construction: case study at Mound City, Ohio, USA

    NASA Astrophysics Data System (ADS)

    Schneider, B. B.; Mandel, R. D.; Tsoflias, G. P.; De Vore, S. L.; Lynott, M.

    2016-06-01

    Mound City, located at the Hopewell Culture National Historical Park in south-central Ohio, USA, is a prehistoric earthwork (200 BC-500 AD) that consists of 24 mounds enclosed in a square embankment wall and is surrounded by eight pits. Recent excavation of two of these pits resulted in the discovery of a clay loam liner that appears to have been placed on the floor of the pits by a prehistoric society known as the Hopewell. The aim of this study was to determine the spatial pattern of this liner in one of the pits using non-invasive geophysical techniques, specifically electrical resistivity and ground-penetrating radar. Minimally invasive soil augers and a test trench yielded information that was used to corroborate interpretations of the geophysical data. The geophysical methods proved to be useful in locating and defining the remnants of the prehistoric clay loam liner, and the results of our investigation indicate that almost 50% of the liner still remains in the pit today. This discovery supports a new interpretation that the Hopewell excavated and preserved the pits at the Mound City site because they served as cultural landscape features.

  14. Termite mounds as hot spots of nitrous oxide emissions in South-Sudanian savanna of Burkina Faso (West Africa)

    NASA Astrophysics Data System (ADS)

    Brümmer, Christian; Papen, Hans; Wassmann, Reiner; Brüggemann, Nicolas

    2009-05-01

    Despite a considerable knowledge of the significant role of termites in the global methane budget, very little is known about their contribution to the global nitrous oxide (N2O) budget. Release of N2O from termite (Cubitermes fungifaber) mounds was measured at a natural savanna site in the southwest of Burkina Faso from May to September 2006. Termite N2O emissions were around 20 μg N2O-N m-2 h-1 at the end of the dry season, and up to two orders of magnitude higher than N2O emissions from the surrounding termite-free soil after the onset of the rainy season. The average N2O emission rate from termite mounds during the observation period was 204 μg N2O-N m-2 h-1, and termite mounds contributed 3.0% to total N2O emissions from this savanna ecosystem. However, in other tropical terrestrial ecosystems with other termite species and/or higher termite density this share might be significantly higher.

  15. Modelling effects of tree population dynamics, tree throw and pit-mound formation/diffusion on microtopography over time in different forest settings

    NASA Astrophysics Data System (ADS)

    Martin, Y. E.; Johnson, E. A.; Gallaway, J.; Chaikina, O.

    2011-12-01

    Herein we conduct a followup investigation to an earlier research project in which we developed a numerical model of tree population dynamics, tree throw, and sediment transport associated with the formation of pit-mound features for Hawk Creek watershed, Canadian Rockies (Gallaway et al., 2009). We extend this earlier work by exploring the most appropriate transport relations to simulate the diffusion over time of newly-formed pit-pound features due to tree throw. We combine our earlier model with a landscape development model that can incorporate these diffusive transport relations. Using these combined models, changes in hillslope microtopography over time associated with the formation of pit-mound features and their decay will be investigated. The following ideas have motivated this particular study: (i) Rates of pit-mound degradation remain a source of almost complete speculation, as there is almost no long-term information on process rates. Therefore, we will attempt to tackle the issue of pit-mound degradation in a methodical way that can guide future field studies; (ii) The degree of visible pit-mound topography at any point in time on the landscape is a joint function of the rate of formation of new pit-mound features due to tree death/topple and their magnitude vs. the rate of decay of pit-mound features. An example of one interesting observation that arises is the following: it appears that pit-mound topography is often more pronounced in some eastern North American forests vs. field sites along the eastern slopes of the Canadian Rockies. Why is this the case? Our investigation begins by considering whether pit-mound decay might occur by linear or nonlinear diffusion. What differences might arise depending on which diffusive approach is adopted? What is the magnitude of transport rates associated with these possible forms of transport relations? We explore linear and nonlinear diffusion at varying rates and for different sizes of pit-mound pairs using a

  16. Statement of basis/proposed plan for the Central Shops Burning/Rubble Pit (631-6G). Revision 1, Final

    SciTech Connect

    Palmer, E.

    1996-10-24

    The purpose of this plan is to describe the preferred alternative for addressing the Central Shops Burning/Rubble Pit 631-6G (BRP6G) located at SRS, in northwestern Barnwell County, South Carolina and to provide an opportunity for public input into the remedial action selection process. Arsenic, beryllium, iron, and octachloro-dibenzo-p-dioxin isomers (OCDD) concentrations in the pit soil are at levels consistent with those found in the background. Therefore, the only contamination attributable to actions in BRP6G is PCB-1254. After the risk contributions of these chemicals are eliminated, the only remaining risk attributable to the pit soil is from PCB-1254 (about 2 {times} 10{sup {minus}6} via ingestion of vegetables grown on-site). The maximum concentration of PCB-1254 detected in the pit was 0.115 mg/kg, approximately 10% of the residential action level for PCBs of 1 mg/kg. Based on the results of the remedial investigation and the BRA, it is proposed that No Action be performed for the BRP6G. Considering the low levels of residual contamination present principally below 1.2 meters (4 feet) within the pit and the associated risks (about 2 {times} 10{sup {minus}6}) within the lower level of EPA`s target risk range, action is not warranted for this unit.

  17. Dig-face monitoring during excavation of a radioactive plume at Mound Laboratory, Ohio

    SciTech Connect

    Josten, N.E.; Gehrke, R.J.; Carpenter, M.V.

    1995-12-01

    A dig-face monitoring system consists of onsite hardware for collecting information on changing chemical, radiological, and physical conditions in the subsurface soil during the hazardous site excavation. A prototype dig-face system was take to Mount Laboratory for a first trial. Mound Area 7 was the site of historical disposals of {sup 232}Th, {sup 227}Ac, and assorted debris. The system was used to monitor a deep excavation aimed at removing {sup 227}Ac-contaminated soils. Radiological, geophysical, and topographic sensors were used to scan across the excavation dig-face at four successive depths as soil was removed. A 3-D image of the contamination plumes was developed; the radiation sensor data indicated that only a small portion of the excavated soil volume was contaminated. The spatial information produced by the dig-face system was used to direct the excavation activities into the area containing the {sup 227}Ac and to evaluate options for handling the separate {sup 232}Th plume.

  18. Structure and composition of organic reefs and carbonate mud mounds: concepts and categories

    NASA Astrophysics Data System (ADS)

    Riding, Robert

    2002-07-01

    organisms are skeletal, synsedimentary cementation imparts extra strength and stability to what otherwise would be a Cluster or Frame Reef, and results in Skeleton-Cement Reefs. Cement Reefs exhibit complex relationships between cement, matrix and skeletons. Agglutinated Microbial, Cluster and Segment reefs tend to be structurally simple, have low primary relief, and may show bedding. Frame (including microbial Microframe) and Cement Reefs tend to be unbedded, structurally complex, and can have high relief. Carbonate Mud Mounds: carbonate mud-dominated deposits with topographic relief and few or no stromatolites, thrombolites or in place skeletons. Low Relief Carbonate Mud Mounds are typically thin. High Relief Carbonate Mud Mounds are thick, and internal bedding, slumping, stromatactis cavity systems, and steep marginal slopes may be common. Whereas Organic Reefs are biogenic, calcareous, and are created by essentially in place organisms, Carbonate Mud Mounds can be organic and/or inorganic in origin and it can be difficult to distinguish their origins.

  19. Perturbation of baseline thermal stress in the Mound 9516 Shipping Package primary containment vessel

    NASA Astrophysics Data System (ADS)

    Sansalone, Keith H. F.

    1995-01-01

    Full-capacity loading of heat sources into the Mound 9516 Shipping Package primary containment vessel (PCV) results in temperature gradients which are symmetric, due to the axisymmetry of the package design. Concern over the change in thermal gradients (and therefore, stress) in the PCV due to sub-capacity loading led to the analytical examination of this phenomenon. The PCVs are cylindrical in shape and are loaded into the package such that they and all containment components are concentrically arranged along a common longitudinal axis. If the design full-capacity loading of the PCVs in this package assumes the axisymmetric (or more precisely, cyclicly symmetric) arrangement of its heat-producing contents, then sub-capacity loading implies that in many cases, the load arrangement could be asymmetric with respect to the longitudinal axis. It is then feasible that the departure from heat load axisymmetry could perturb the nominal thermal gradients so that thermally-induced stress within the PCV might increase to levels deemed unacceptable. This study applies Finite Element analysis (FEA) to the problem and demonstrates that no such unacceptable thermal stress increase occurs in the PCV material due to the asymmetric arrangement of contents.

  20. Perturbation of baseline thermal stress in the Mound 9516 Shipping Package primary containment vessel

    SciTech Connect

    Sansalone, K.H.F.

    1995-01-20

    Full-capacity loading of heat sources into the Mound 9516 Shipping Package primary containment vessel (PCV) results in temperature gradients which are symmetric, due to the axisymmetry of the package design. Concern over the change in thermal gradients (and therefore, stress) in the PCV due to sub-capacity loading led to the analytical examination of this phenomenon. The PCVs are cylindrical in shape and are loaded into the package such that they and all containment components are concentrically arranged along a common longitudinal axis. If the design full-capacity loading of the PCVs in this package assumes the axisymmetric (or more precisely, cyclicly symmetric) arrangement of its heat-producing contents, then sub-capacity loading implies that in many cases, the load arrangement could be asymmetric with respect to the longitudinal axis. It is then feasible that the departure from heat load axisymmetry could perturb the nominal thermal gradients so that thermally-induced stress within the PCV might increase to levels deemed unacceptable. This study applies Finite Element analysis (FEA) to the problem and demonstrates that no such unacceptable thermal stress increase occurs in the PCV material due to the asymmetric arrangement of contents. {copyright} 1995 {ital American} {ital Institute} {ital of} {ital Physics}

  1. Amino acid racemization dating of marine shells: A mound of possibilities.

    PubMed

    Demarchi, Beatrice; Williams, Matt G; Milner, Nicky; Russell, Nicola; Bailey, Geoff; Penkman, Kirsty

    2011-07-01

    Shell middens are one of the most important and widespread indicators for human exploitation of marine resources and occupation of coastal environments. Establishing an accurate and reliable chronology for these deposits has fundamental implications for understanding the patterns of human evolution and dispersal. This paper explores the potential application of a new methodology of amino acid racemization (AAR) dating of shell middens and describes a simple protocol to test the suitability of different molluscan species. This protocol provides a preliminary test for the presence of an intracrystalline fraction of proteins (by bleaching experiments and subsequent heating at high temperature), checking the closed system behaviour of this fraction during diagenesis. Only species which pass both tests can be considered suitable for further studies to obtain reliable age information. This amino acid geochronological technique is also applied to midden deposits at two latitudinal extremes: Northern Scotland and the Southern Red Sea. Results obtained in this study indicate that the application of this new method of AAR dating of shells has the potential to aid the geochronological investigation of shell mounds in different areas of the world. PMID:21776187

  2. Amino acid racemization dating of marine shells: A mound of possibilities

    PubMed Central

    Demarchi, Beatrice; Williams, Matt G.; Milner, Nicky; Russell, Nicola; Bailey, Geoff; Penkman, Kirsty

    2011-01-01

    Shell middens are one of the most important and widespread indicators for human exploitation of marine resources and occupation of coastal environments. Establishing an accurate and reliable chronology for these deposits has fundamental implications for understanding the patterns of human evolution and dispersal. This paper explores the potential application of a new methodology of amino acid racemization (AAR) dating of shell middens and describes a simple protocol to test the suitability of different molluscan species. This protocol provides a preliminary test for the presence of an intracrystalline fraction of proteins (by bleaching experiments and subsequent heating at high temperature), checking the closed system behaviour of this fraction during diagenesis. Only species which pass both tests can be considered suitable for further studies to obtain reliable age information. This amino acid geochronological technique is also applied to midden deposits at two latitudinal extremes: Northern Scotland and the Southern Red Sea. Results obtained in this study indicate that the application of this new method of AAR dating of shells has the potential to aid the geochronological investigation of shell mounds in different areas of the world. PMID:21776187

  3. 2011 Mound Site Groundwater Plume Rebound Exercise and Follow-Up - 13440

    SciTech Connect

    Hooten, Gwendolyn; Cato, Rebecca; Lupton, Greg

    2013-07-01

    The Mound Site facility near Miamisburg, Ohio, opened in 1948 to support early atomic weapons programs. It grew into a research, development, and production facility performing work in support of the U.S. Department of Energy (DOE) weapons and energy programs. The plant was in operation until 1995. During the course of operation, an onsite landfill was created. The landfill was located over a finger of a buried valley aquifer, which is a sole drinking water source for much of the Miami Valley. In the 1980's, volatile organic compounds (VOCs) were discovered in groundwater at the Mound site. The site was placed on the National Priorities List on November 21, 1989. DOE signed a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Federal Facility Agreement with the U.S. Environmental Protection Agency (EPA) and the Ohio Environmental Protection Agency. The agreement became effective in October 1990. The area that included the landfill was designated Operational Unit 1 (OU-1). In 1995, a Record of Decision was signed that called for the installation and operation of a pump and treatment (P and T) system in order to prevent the VOCs in OU-1 groundwater from being captured by the onsite water production wells. In addition to the P and T system, a soil vapor extraction (SVE) system was installed in 1997 to accelerate removal of VOCs from groundwater in the OU-1 area. The SVE system was successful in removing large amounts of VOCs and continued to operate until 2007, when the amount of VOCs removed became minimal. A rebound study was started in February 2003 to determine how the groundwater system and contaminants would respond to shutting down the P and T system. The rebound test was stopped in February 2004 because predetermined VOC threshold concentrations were exceeded down-gradient of the landfill. The P and T and SVE systems were restarted after the termination of the rebound test. In 2006, the remediation of the Mound site was completed

  4. Chemotrophic filamentous microfossils from the Hollard Mound (Devonian, Morocco) as investigated by focused ion beam.

    PubMed

    Cavalazzi, Barbara

    2007-04-01

    The biologic origin of objects with microbe-like morphologies from the oldest preserved terrestrial sedimentary rocks remains a matter of controversy. Their biogenicity has been questioned, as well as the claim that they are convincing evidence of early life. Though minerals with microbe-like morphologies represent ambiguous evidence of life, they are, in a number of conditions, the only achievable information. In this study, the focused ion beam (FIB) electron microscopy technique was used for nano and micrometer-scale high-resolution imaging and in situ microsectioning of filamentous microfossils. The structural elements of these filaments, their spatial relationships with the host rock, and artifacts produced by alteration of the original morphology due to laboratory sample processing have been clearly defined. The in situ sectioning provided a means by which to investigate surface and subsurface microstructures and perform different analytical techniques on the same object, which minimizes sample destruction and avoids excessive manual handling and exposure of the specimen during analysis. Improvement in the morphological and compositional evaluation of the filaments has facilitated the development of a hypothesis regarding the metabolic pathway of the filamentous microfossils preserved in the Middle Devonian-aged Hollard Mound deposit, Anti-Atlas, Morocco. The results of this study demonstrate the potential of the FIB/SEM (scanning electron microscopy) system for detecting microbial-scale morphologies. PMID:17480168

  5. Geologic map of the Mound Spring quadrangle, Nye and Clark Counties, Nevada, and Inyo County, California

    USGS Publications Warehouse

    Lundstrom, Scott C.; Mahan, Shannon; Blakely, Richard J.; Paces, James B.; Young, Owen D.; Workman, Jeremiah B.; Dixon, Gary L.

    2003-01-01

    The Mound Spring quadrangle, the southwestern-most 7.5' quadrangle of the area of the Las Vegas 1:100,000-scale quadrangle, is entirely within the Pahrump Valley, spanning the Nevada/California State line. New geologic mapping of the predominantly Quaternary materials is combined with new studies of gravity and geochronology in this quadrangle. Eleven predominantly fine-grained units are delineated, including playa sediment, dune sand, and deposits associated with several cycles of past groundwater discharge and distal fan sedimentation. These units are intercalated with 5 predominantly coarse-grained alluvial-fan and wash gravel units mainly derived from the Spring Mountains. The gravel units are distinguished on the basis of soil development and associated surficial characteristics. Thermoluminescence and U-series geochronology constrain most of the units to the Holocene and late and middle Pleistocene. Deposits of late Pleistocene groundwater discharge in the northeast part of the quadrangle are associated with a down-to-the-southwest fault zone that is expressed by surface fault scarps and a steep gravity gradient. The gravity field also defines a northwest-trending uplift along the State line, in which the oldest sediments are poorly exposed. About 2 km to the northeast a prominent southwest-facing erosional escarpment is formed by resistant beds in middle Pleistocene fine-grained sediments that dip northeast away from the uplift. These sediments include cycles of groundwater discharge that were probably caused by upwelling of southwesterly groundwater flow that encountered the horst.

  6. The structure of iron-hydroxide mounds at hydrothermal environment in shallow marine, Satsuma Iwo-Jima, Kikai caldera, Japan

    NASA Astrophysics Data System (ADS)

    Kuratomi, T.; Kiyokawa, S.; Ikehara, M.; Goto, S.; Hoshino, T.; Ikegami, F.; Minowa, Y.

    2013-12-01

    Satsuma Iwo-Jima Island, located 38km south of Kyusyu, Japan, is a volcanic island in the northwestern rim of Kikai caldera. Iron-rich mounds develop with hydrothermal activity (pH=5.5, 50-60 °C) in Nagahama bay southwestern this island. The brownish seawater at the bay is due to mixing of the hot spring water (Shikaura and Tazaki, 2001) with the high deposition rate (1 m per year) of iron-rich sediments (Kiyokawa et al., 2012). In this study, we found the structure of mounds has unique information by the observation with X-ray CT scan, FE-SEM, and the thin-sectioned sample, and the chemical analysis with EDS, XRF, and XRD. Samples (20-30 cm long) were piece of mounds made from two layers: black high-density hard layer and brownish low-density soft layer. X-ray CT scan observation shows that the inside of samples is constructed from the aggregation of convex structure (3-4 cm). Low-density layers have many pipe-like structure (typical radius: 1 mm). Petrographic observations indicate that both high- and low-density layers have filament-like forms, however the form in low-density layer is perpendicular to those in high-density layer. In low-density layer, small particles on the filament-like form and the number increases toward high-density layer. FE-SEM observation shows that filament-like form in high-density layer consists of aggregation of bacillus-like form as the chain of particles (about 2 μm). At low-density layer, on the other hand, bacteria-like form with smaller particles (<1 μm) is observed. Bacteria-like form could be classified into 3 types (helix, ribbon-like, twisted). Furthermore, all particles are iron-hydroxides such as ferrihydrite with silica because they are consist of Fe, Si and O with broad peak in XRD. We conclude that the mounds at Nagahama bay were constructed form aggregation of convex structure with many pipes as the hydrothermal vent. Bacteria-like form probably is the stalk of neutrophilic, iron-oxidizing bacteria because of those

  7. Beaufort Sea deep-water gas hydrate recovery from a seafloor mound in a region of widespread BSR occurrence

    USGS Publications Warehouse

    Hart, Patrick E.; Pohlman, John W.; Lorenson, T.D.; Edwards, Brian D.

    2011-01-01

    Gas hydrate was recovered from the Alaskan Beaufort Sea slope north of Camden Bay in August 2010 during a U.S. Coast Guard Cutter Healy expedition (USCG cruise ID HLY1002) under the direction of the U.S. Geological Survey (USGS). Interpretation of multichannel seismic (MCS) reflection data collected in 1977 by the USGS across the Beaufort Sea continental margin identified a regional bottom simulating reflection (BSR), indicating that a large segment of the Beaufort Sea slope is underlain by gas hydrate. During HLY1002, gas hydrate was sampled by serendipity with a piston core targeting a steep-sided bathymetric high originally thought to be an outcrop of older, exposed strata. The feature cored is an approximately 1100m diameter, 130 m high conical mound, referred to here as the Canning Seafloor Mound (CSM), which overlies the crest of a buried anticline in a region of sub-parallel compressional folds beneath the eastern Beaufort outer slope. An MCS profile shows a prominent BSR upslope and downslope from the mound. The absence of a BSR beneath the CSM and occurrence of gas hydrate near the summit indicates that free gas has migrated via deep-rooted thrust faults or by structural focusing up the flanks of the anticline to the seafloor. Gas hydrate recovered from near the CSM summit at a subbottom depth of about 5.7 meters in a water depth of 2538 m was of nodular and vein-filling morphology. Although the hydrate was not preserved, residual gas from the core liner contained >95% methane by volume when corrected for atmospheric contamination. The presence of trace C4+hydrocarbons (<0.1% by volume) confirms at least a minor thermogenic component. Authigenic carbonates and mollusk shells found throughout the core indicate sustained methane-rich fluid advection and possible sediment extrusion contributing to the development of the mound. Blister-like inflation of the seafloor caused by formation and accumulation of shallow hydrate lenses is also a likely factor in CSM

  8. Organic matter remains in the Kess Kess mounds of the Hamar Laghadad (Anti Atlas, Morocco): record of microbial biomineralization

    NASA Astrophysics Data System (ADS)

    Demasi, Fabio; Barbieri, Roberto; Guido, Adriano; Mastandrea, Adelaide; Cavalazzi, Barbara; Russo, Franco

    2010-05-01

    Carbonate Mud Mounds are well documented in the geological record, and span from Proterozoic to recent times, in shallow- and deep-water settings. They are a significant expression of the history of Earth's microbial life. The origin of carbonate mud-mounds has long been debated and the discovery of seep- and vent-related ecosystems from different geotectonic settings, associated to authigenic carbonate mounds, allowed the re-interpretation of some mounds as the product of chemosynthetic microbial mediation. We analyzed the carbonate mounds, informally called 'Kess-Kess', cropping out in the Hamar Laghdad Ridge, eastern Anti-Atlas, SE Morocco. These mounds are the most spectacularly exposed carbonate buildups of the world and, due to differential erosion, they show their original shapes and the relationships with associated strata. The origin of these buildups is still under debate and the most consistent hypotheses are related to submarine hydrothermal vents or hydrocarbon seapage in which bacteria and/or archaea plaied a prominent role in the carbonate biomineralization. To investigate the possible remains of prokaryote metabolic activity we studied the micrite precipitation processes through microfacies and biogeochemical analyses. The more indicative micrite texture is stromatolitic with very fine wrinkled lamination organized in antigravitative pattern. High resolution SEM observations suggest the presence of widespread trace of organic phantoms. The geochemical characterization of extracted organic matter was performed through the functional group analyses by FT-IR spectroscopy. The infrared spectra showed bands between 600 and 3000 cm-1. They contain stretching aliphatic bands (νCHali) at 2950, 2925 and 2850 cm-1, and deformation bands of methyl (δCH3; 1365 cm-1) and both methyl and methylene [δ(CH2 + CH3); 1458 cm-1] groups. The spectra also display the band assigned to carbonyl and/or carboxyl groups (νC=O; 1740 cm-1). The νC-O vibration appears

  9. Reconstructing the Palaeogeographies of a Neolithic - Bronze Age Settlement Mound at Ephesos, Turkey

    NASA Astrophysics Data System (ADS)

    Ehlers, Lisa; Friederike, Stock; Barbara, Horejs; Helmut, Brückner

    2014-05-01

    Although Ephesos and its surroundings has long been an area of archaeological interest and investigations, the focus has mainly been on sites related to Antiquity and Late Antiquity. Until recently systematic research concerning prehistoric phases of occupation within this region have been lacking. Due to the growing interest in these time periods along the West Anatolian coast, archaeological research projects involving the study of the newly discovered prehistoric settlement mounds located in the vicinity of the prominent ancient city were initiated. The aim of this study was to examine the palaeogeographical and geoarchaeological contexts of the mound (tell), Çukuriçi Höyük, in order to determine the thickness and age of the settlement layers as well as the spatial extent of the tell throughout the different periods of settlement. As additional research to the excavations, 20 sediment cores drilled on and around Çukuriçi Höyük were examined and their physical and geochemical properties as well as existing data were used to reconstruct the palaeoenvironment. The chronostratigraphy relies on AMS-14C ages and findings of diagnostic ceramics; a further attempt was made by luminescence dating. The results reveal that the inhabitants intentionally choose the location due to the beneficial topography, initially, i.e. during Pottery Neolithic times in the early 7th mill. BC, lying upon an elevation within a fertile alluvial plain about 1.5-2 km away from the coast. It seems that during the time of settling (Pottery Neolithic - Early Bronze Age) several rivers flowed in the direct vicinity of the tell. The elevated terrain provided the inhabitants security from the torrents. In addition, the corings reveal that the tell covers an area of about 11,000 m2 and a thickness of settlement layers of c. 8 m. Finally, as a possible result of water management conducted by the inhabitants, sediments related to low-energy depositional conditions are identified at the foot of

  10. Petrology of a Jurassic cold seep carbonate mound, Great Valley Group, northern California

    SciTech Connect

    Campbell, K.A.; Bottjer, D.J. . Dept. of Geological Sciences)

    1992-01-01

    Ancient sites of chemosynthetic marine invertebrate communities have been increasingly described from the stratigraphic record. Fossil cold seeps are best identified by the stratigraphically restricted co-occurrence of anomalous carbonates and fossils of organisms that in modern environments are chemosymbiotic. A Late Jurassic (Tithonian) age fossil seep site is preserved in deep-water turbidites of the Stony Creek Formation (Great Valley Group). Two low-relief carbonate mounds contain an abundant and diverse fossil macrofauna including taxa whose modern counterparts are chemosymbiotic, as well as several associate taxa. Two broad carbonate fabric types are present: a bioturbated, peloidal, fossiliferous micrite with abundant flecks of organic matter and several wavy laminated marine cements. The micrite and cements are either irregularly interlayered on distinctly separated by corrosion surfaces coated with iron oxides that may mark pulses of H[sub 2]S-rich fluids to the seep. Petrographic observations indicate the following idealized paragenetic sequence: deposition of micrite, with contemporaneous biotic activity; corrosion event, with preferential preservation of some peloids; precipitation of pyrite on some corrosion surfaces and concentration of insoluble siltstone linings where corrosion has opened vugs; precipitation of blocky yellow calcite cement with organic-rich inclusions in void spaces and around peloids; growth of clear to gray, botryoidal to fibrous cement; and precipitation of late, clear calcite spar. Similar fabrics and abundant tube-like structures are present in another Great Valley carbonate lens of Early Cretaceous (Albian-Aptian) age exposed on the Cold Fork of Cottonwood Creek near Red Bluff, California. Detailed integration of petrological studies of these fabrics with stable isotope studies and fossil faunal distributions provide a powerful approach for understanding the history of development and individual fossil seeps.

  11. Groundwater Mounding in Non-uniform Aquifers with Implications for Managed Aquifer Recharge

    NASA Astrophysics Data System (ADS)

    Zlotnik, V. A.; Noel, P.; Kacimov, A. R.; Al Maktoumi, A. K.

    2015-12-01

    Many areas of the world (e.g. the Middle East and North Africa countries) are deficient in observation networks and hydrogeological data needed for Managed Aquifer Recharge (MAR) design. Therefore, diagnostic analytical approaches are appropriate for feasibility studies of MAR. It was found that the common assumption of aquifer thickness uniformity often does not hold, especially in mountainous watersheds. However, the only practical result available for non-uniform aquifers was developed for well hydraulics applications (point sinks or sources) by Hantush (1962), while the recharge zones may cover large areas on the scale of kilometers, such as temporarily filled impoundments (natural and engineered reservoirs in wadis, depressions, trenches, etc.) or perennial streams accepting massive treated wastewater discharge. To address these important, but overlooked MAR problems in sloping aquifers, a set of new closed-form analytical solutions for water table elevations were obtained. Interestingly, the 2D groundwater flow equation acquires the advection-dispersion equation form in these cases. The quadratures in closed-form solutions obtained by the Green's function method converge rapidly. These models account for both shapes and orientations of sources with respect to the direction of the aquifer base gradient. Qualitatively, solutions in sloping aquifers have an important trait: the mounding is limited in time and space, unlike in aquifers with a horizontal base. Aquifers with the greater slopes have the lesser potential of waterlogging from the rising water table and different storage characteristics (height and volume of locally stored water). Computational aspects of these solutions for MAR analyses are illustrated by example utilizing regional aquifer properties near Az Zarqa River, Jordan. (This study was supported by a grant from USAID-FABRI, project contract: AID-OAA-TO-11-00049, Subcontract: 1001624 -12S-19745).

  12. Mound measurements - quantifying medium-term soil erosion under olive trees in Northern Jordan

    NASA Astrophysics Data System (ADS)

    Kraushaar, S.; Herrmann, N.; Ollesch, G.; Vogel, H.-J.; Siebert, C.

    2014-05-01

    Over the last few decades many quantitative erosion studies have revealed that olive orchard expansion and increased mechanization in southern European countries have led to increased soil erosion under olive trees. Consequently, these studies have suggested different methods of mitigation. In light of the 2014 European trading zone expansion to countries east and south of the Mediterranean, a further intensification of olive plantations is postulated to meet market demands. To attain first medium-term estimates of erosion in Northern Jordan and its driving factors, a new method measuring olive mounds was implemented. Seven fields with clearly erosive structures were chosen throughout the Wadi Al-Arab catchment in Northern Jordan. Topographic measurements were used to reconstruct the historical and recent surface level and calculate the volume eroded since the planting of the trees. A total of 81 bulk density measurements and 14 tree cores allowed the estimation of the soil loss in tons per hectare. The combination of modified land use map and slope information helped to identify similar olive fields with high erosive potential. Results show that the method provides medium-term quantitative estimates for averaged soil loss consistent with some existing results from similar research areas in the Mediterranean. They clearly indicate the significant potential for erosion in olive orchards with around 95 ± 8 t ha- 1 yr- 1. Tillage practice and water erosion were identified as critical erosion processes, both depending on tillage characteristics, tillage timing, and soil parent material. The investigated fields represent about 19% of the catchment's surface area and are likely to contribute to the measured yearly sediment yield that fills up the Wadi Al-Arab reservoir with sediments.

  13. Ice in Channels and Ice-Rock Mixtures in Valleys on Mars: Did They Slide on Deformable Rubble Like Antarctic Ice Streams?

    NASA Technical Reports Server (NTRS)

    Lucchitta, B. K.

    1997-01-01

    Recent studies of ice streams in Antarctica reveal a mechanism of basal motion that may apply to channels and valleys on Mars. The mechanism is sliding of the ice on deformable water-saturated till under high pore pressures. It has been suggested by Lucchitta that ice was present in outflow channels on Mars and gave them their distinctive morphology. This ice may have slid like Antarctic ice streams but on rubbly weathering products rather than till. However, to generate water under high pore pressures, elevated heatflow is needed to melt the base of the ice. Either volcanism or higher heatflow more than 2 b.y. ago could have raised the basal temperature. Regarding valley networks, higher heatflow 3 b.y. ago could have allowed sliding of ice-saturated overburden at a few hundred meters depth. If the original, pristine valleys were somewhat deeper than they are now, they could have formed by the same mechanism. Recent sounding of the seafloor in front of the Ross Ice Shelf in Antarctica reveals large persistent patterns of longitudinal megaflutes and drumlinoid forms, which bear remarkable resemblance to longitudinal grooves and highly elongated streamlined islands found on the floors of martian outflow channels. The flutes are interpreted to have formed at the base of ice streams during the last glacial advance. Additional similarities of Antarctic ice streams with martian outflow channels are apparent. Antarctic ice streams are 30 to 80 km wide and hundreds of kilometers long. Martian outflow channels have similar dimensions. Ice stream beds are below sea level. Carr determined that most common floor elevations of martian outflow channels lie below martian datum, which may have been close to or below past martian sea levels. The Antarctic ice stream bed gradient is flat and locally may go uphill, and surface slopes are exceptionally. Martian channels also have floor gradients that are shallow or go uphill locally and have low surface gradients. The depth to the

  14. MEST-Do the ``rubble-pile'' asteroid-1950 DA, with low 1700 kg/m3 density, has a structure with spacetime center?

    NASA Astrophysics Data System (ADS)

    Cao, Dayong

    2015-04-01

    According to Einstein's equation and observation of flat universe, the paper gives new ideas both of dark massenergy and spacetime center, and supporses that some asteroids were comets which have spacetime center, and some comets were wraped up by rock in 2012. It explains of a observation about low density of the asteroid-1950 DA by spacetime center of the asteroid. (see Ben Rozitis, ``Cohesive forces prevent the rotational breakup of rubble-pile asteroid (29075) 1950 DA,'' http://www. nature.com / nature / journal / v512 / n7513/full/nature13632.html) It also can explain of a rock hull of 67P/Churyumov-Gerasimenko. (see Jonathan O'Callaghan, ``Comets are like deep fried ICE CREAM: Nasa ice-box experiment confirms 67P is hard on the outside but fluffy on the inside,'' http://www.dailymail.co.uk/sciencetech/article-2949020/Comets-like-deep-fried-ICE-CREAM-Nasa-ice-box-experiment-confirms-67P-hard-outside-fluffy-inside.html) (See Dayong Cao, ``MEST-The dark hole, dark comet and dark matter are the space-time center'' and ``MEST- avoid next extinction by a space-time effect'') http://meetings.aps.org/link/BAPS.2014.APR.L1.3 http://meetings.aps.org/link/BAPS.2014.APR.L1.2 http://meetings.aps.org/link/BAPS.2015.APR.L1.2 http://meeting.aps.org/Meeting/CAL12/Session/H1.8 http://meetings.aps.org/link/BAPS.2012.APR.K1.79

  15. Simulating the influence of two shallow, flow-through lakes on a groundwater system: implications for groundwater mounds and hinge lines

    NASA Astrophysics Data System (ADS)

    Gosselin, David C.; Khisty, Mohan J.

    2001-10-01

    Groundwater mounds and hinge lines are important features related to the interaction of groundwater and lakes. In contrast to the transient formation of groundwater mounds, numerical simulations indicate that permanent groundwater mounds form between closely spaced lakes as the natural consequence of adding two net sinks to a groundwater flow system. The location of the groundwater mound and the position of the hinge lines between the two lakes are intimately related. As the position of the mound changes there is a corresponding shift in the position of the hinge line. This results in a change in the ratio of groundwater inflow to outflow (Qi/Qo) for the lake. The response of the lake is an increase or decrease in the lake level. Our simulations indicate that the movement of the hinge line in a natural system is a consequence of the dynamic interrelationships between recharge, the slope of the water table upgradient and downgradient of the lake, and the loss of water from the lake by evaporation. The extent of the seasonal movement of the hinge line will vary from one year to the next depending on local changes in the magnitude of the hydrologic variables.

  16. Cold-water coral mounds and sponge-beds as habitats for demersal fish on the Norwegian shelf

    NASA Astrophysics Data System (ADS)

    Kutti, Tina; Bergstad, Odd Aksel; Fosså, Jan Helge; Helle, Kristin

    2014-01-01

    The importance of cold-water coral (CWC) mounds and sponge-beds as habitat for demersal fish was examined in the Træna Deep marine protected area and adjacent areas of the Norwegian continental shelf. Standardised longline fishing was conducted twice, in June and March, and predetermined fishing effort was allocated to multiple plots with varying densities of small CWC mounds and sponges, plus control plots with neither of these habitats. Catches within all examined habitats were dominated by the commercially exploited Brosme brosme (representing >70% of the total catch) followed by Galeus melastomus, Chimaera monstrosa, Etmopterus spinax and the commercially exploited Molva molva. Positive correlations were found between catch rates of B. brosme, G. melastomus and C. monstrosa and the density of small CWC mounds at one or both sampling occasions. No correlations were found between the catch rates of the same three species and sponge density; thus the sponge-beds did not seem to represent an ecologically equivalent habitat to the CWCs. On a local scale the CWC habitat appeared to attract higher abundances of B. brosme, G. melastomus and C. monstrosa; however, the differences in catch rates between coral and non-coral areas were quite low (2-4 times) and for most species the fish-habitat relationships varied temporarily and with the spatial scale used to delineate the habitat. Based on the methods and the results of this study and the fact that CWCs only occupy a very small proportion of the Norwegian shelf, the importance of CWCs as habitat for the populations of the demersal fish species examined is judged as marginal.

  17. Vertical movements of frost mounds in sub-Arctic permafrost regions analyzed using geodetic survey and satellite interferometry

    NASA Astrophysics Data System (ADS)

    Beck, I.; Ludwig, R.; Bernier, M.; Strozzi, T.; Boike, J.

    2015-04-01

    Permafrost-affected soils cover about 45% of Canada. The environment in such areas, especially those located within the discontinuous permafrost zone, has been impacted more than any other by recorded climatic changes. A number of changes, such as surface subsidence and the degradation of frost mounds due to permafrost thawing have already been observed at many locations. We surveyed three frost mounds (lithalsas) close to Umiujaq, northern Quebec, sub-Arctic, using a high-precision differential Global Positioning System (d-GPS) during field visits in 2009, 2010 and 2011, thus obtaining detailed information on their responses to the freezing and thawing that occurs during the course of the annual temperature cycle. Seasonal pulsations were detected in the frost mounds and these responses were shown to vary with the state of degradation and the land cover. The most degraded lithalsa showed a maximum amplitude of vertical movement (either up or down) between winter and summer (thawing) of 0.19 ± 0.09 m over the study period, while for the least degraded lithalsa this figure was far greater (1.24 ± 0.47 m). Records from patches with little or no vegetation showed far less average vertical movement over the study period (0.17 ± 0.03 m) than those with prostrate shrubs (0.56 ± 0.02 m), suggesting an influence from the land-cover. A differential Interferometric Synthetic Aperature Radar (D-InSAR) analysis was also completed over the lithalsas using selected TerraSAR-X images acquired from April to October 2009 and from March to October 2010, with a repeat cycle of 11 days. Interferograms with baselines shorter than 200 m were computed revealing a generally very low interferometric coherence, restricting the quantification of vertical movements of the lithalsas. Vertical surface movements in the centimeter range were recorded in the near vicinity of Umiujaq.

  18. The 2.6 Ma depositional sequence from the Challenger cold-water coral carbonate mound (IODP Exp. 307): a unique palaeo-record of Plio-Pleistocene NE Atlantic climate variability

    NASA Astrophysics Data System (ADS)

    Thierens, M. M.; Pirlet, H.; Titschack, J.; Colin, C. C.; Dorschel, B.; Huvenne, V. A.; Wheeler, A. J.; Stuut, J. W.; Latruwe, K.; Vanhaecke, F. F.; O Donnell, R. D.; Henriet, J.

    2009-12-01

    During IODP Expedition 307, the first complete sequence through a cold-water coral carbonate mound (a bio-geological seafloor feature created through successive stages of cold-water coral mediated sediment accumulation) was successfully acquired. The recovery of the Challenger Mound record, one of the large (ca. 155 m high) cold-water coral carbonate mounds along the NE Atlantic continental margin (Belgica Mounds,eastern Porcupine Seabight), finally facilitates the study of an entire coral carbonate mound’s development process and allows the identification of the environmental conditions driving and maintaining the build-up of these remarkable seafloor habitats. Furthermore, due to its location along the NE Atlantic continental margin, the Challenger Mound sequence contains a potential record of continent-ocean climatic evolution during the Plio-Pleistocene [1,2]. In this study, the different sediment contributors to the Challenger Mound are identified and assessed throughout its entire sedimentary sequence. High resolution siliciclastic particle-size end-member modelling and its ground-truthing (XRD, quartz-sand surface microtextures) indicate the dominant influence of a climatically-steered contour-current system. Iceberg rafting is identified as important depositional mechanism throughout the whole mound development. Furthermore, new evidence (Nd-Sr isotopes of ice-rafted grains) for locally-derived icebergs reaching the eastern Porcupine Seabight continental margin, even in the early stages of Northern Hemisphere glacial expansion, is preserved in the mound sequence. The Challenger Mound reveals a two-phase development, separated by a significant hiatus (from 1.7 to 1 Ma [1,2]). The lower mound-phase indicates a (semi-)continuous, fast accumulating current-controlled depositional environment, while the condensed upper mound-phase bears witness of the distinct shift to a more glacially-influenced, more varying global environment since the mid

  19. Oxygen and sulfur isotope composition of sulfate-rich evaporite mounds at the Lewis Cliffs Ice Tongue, Transantarctic Mountains, Antarctica

    NASA Astrophysics Data System (ADS)

    Socki, R. A.; Sun, T.; Bish, D. L.; Harvey, R. P.; Tonui, E.; Bao, H.

    2009-12-01

    We report the O and S isotope compositions of massive localized deposits of sodium sulfate composed nearly entirely of the mineral thenardite (Na2SO4) and its hydrate, mirabilite (Na2SO4.10H2O) collected from evaporite mounds occurring on the glacial end moraine of the Lewis Cliff Ice Tongue, Antarctica. Mounds are typically situated near the edges of small evaporative brine lakes of unknown depths. Sulfate-rich evaporite mounds at Lewis Cliff Ice Tongue have low δ18O values (average value = -17.2‰ (VSMOW)) and anomalously high δ34S values (average value = +49.1‰ (VCDT)). O and D isotope compositions of these brine lake waters confirm that they are derived from a mixture of glacial ice and snow that underwent evaporation. The highly negative δ18O water values (-30.8‰ to -64.2‰ (VSMOW)) imply the incorporation of this water oxygen into the hydrated sulfate minerals. When coupled with the enriched 34S values, these data point to mirabilite-thenardite mound formation processes involving bacterial sulfate reduction (BSR), followed by precipitation due to evaporation of the concentrated brines. We suggest that sulfate reduction occurs either at the bottom of the evaporative brine lakes, or sub-glacially, as a result of aqueous basal glacial conditions (Alpine-style) or possibly in an as yet unidentified sub-glacial lake. Sulfate 18O is ~30‰ more positive than that of the brine lake water and implies that either 1) sulfate formed directly from the oxidation of reduced sulfur within the brine lakes below ~0°C, during which a ~30‰ fractionation of oxygen isotopes could occur between water and the produced sulfate, or 2) sulfate is derived from the residue of the BSR, but with contribution from the re-oxidation of the intermediate product of BSR, sulfite. Oxygen isotopic exchange occurs between sulfite and ambient water rapidly, which also could introduce ~30‰ fractionation between the water and the sulfite. In turn, the observed sulfate will carry a

  20. Cold-seep-driven carbonate deposits at the Central American forearc: contrasting evolution and timing in escarpment and mound settings

    NASA Astrophysics Data System (ADS)

    Liebetrau, V.; Augustin, N.; Kutterolf, S.; Schmidt, M.; Eisenhauer, A.; Garbe-Schönberg, D.; Weinrebe, W.

    2014-10-01

    Continuous surface cores of cold-seep carbonates were recovered offshore Pacific Nicaragua and Costa Rica from 800 to 1,500-m water depths (Meteor 66/3) in order to decipher their evolution and methane enriched fluid emanation in contrasting geological settings. Cores from the mounds Iguana, Perezoso, Baula V and from the Jaco Scarp escarpment were used for a multi-method approach. For both settings aragonite was revealed as dominant authigenic carbonate phase in vein fillings and matrix cementation, followed by Mg-calcite as second most abundant. This common precipitation process of CaCO3 polymorphs could be ascribed as indirectly driven by chemical changes of the advecting pore water due to anaerobic oxidation of methane. A more direct influence of seep-related microbial activity on the authigenic mineral assemblage in both settings is probably reflected by the observed minor amounts of dolomite and a dolomite-like CaMg carbonate (MgCO3 ~ 42 %). δ13C data of Jaco Scarp samples are significantly lower (-43 to -56 ‰ PDB) than for mound samples (-22 to -36 ‰ PDB), indicating differences in fluid composition and origin. Noteworthy, δ18O values of Scarp samples correlate most closely with the ocean signature at their time of formation. Documenting the archive potential, a high resolution case study of a mound core implies at least 40 changes in fluid supply within a time interval of approximately 14 ky. As most striking difference, the age data indicate a late-stage downward-progressing cementation front for all three mound cap structures (approx. 2-5 cm/ky), but a significantly faster upward carbonate buildup in the bulging sediments on top of the scarp environment (approx. 120 cm/ky). The latter data set leads to the hypothesis of chemoherm carbonate emplacement in accord with reported sedimentation rates until decompression of the advective fluid system, probably caused by the Jaco Scarp landslide and dating this to approximately 13,000 years ago.

  1. Spatial and temporal characterization of a cold seep-hydrate system (Woolsey Mound, deep-water Gulf of Mexico)

    NASA Astrophysics Data System (ADS)

    Simonetti, Antonello

    Cold seeps are areas where methane is transferred from the lithosphere into the hydrosphere, accounting for the major source of hydrocarbons in seawaters. Formation of gas hydrate in cold seeps modulates the global discharge of methane to the environment. However, cold seeps are dynamic settings where hydrates dissociate on short and long time-scales triggering substantial methane fluxes to the oceans. These methane vents sustain unique ecosystems at the ocean floors and contribute to ocean acidification. Also, the methane can potentially reach the sea surface and be exchanged with the atmosphere contributing to global warming. Understanding how cold seep-hydrate systems (CSHSs) operate through time and space is therefore crucial to evaluate their global impact on ocean biogeochemistry and climate. The area investigated is Woolsey Mound, a CSHS located in the Northern Gulf of Mexico. For the first part of the research, the goal was to determine the spatial distribution of subsurface gas hydrate at this site. In terms of hydrate-reservoir category, Woolsey Mound is classified as "seafloor mound" and "fractured mud". To date, these two categories are poorly constrained worldwide. This study documents a successful integration of high-resolution seismic and core data to detect the spatial distribution of hydrates in such settings. The approach adopted and the model may be applied globally for these reservoir categories. The aim of the second part was to untangle the contentious long-term (thousands to millions of years) dynamics driving methane hydrate dissociation and seepage in CSHSs. Analyses on high-resolution seismic data suggest that tectonics is the main forcing mechanism and that CSHSs may operate independently from eustatic fluctuations. This contradicts the broad consensus in the literature about methane seepage in CSHSs being systematically triggered during sea-level lowstand. The third part of the research aimed to characterize the short-term (years

  2. Evaluation of brine disposal from the Bryan Mound site of the Strategic Petroleum Reserve Program. Annual report, September 1981-August 1982. Volume II

    SciTech Connect

    Hann, R.W. Jr.; Randall, R.E.

    1983-06-01

    The Department of Energy's Strategic Petroleum Reserve Program began leaching the Bryan Mound salt dome and discharging brine into the coastal waters offshore of Freeport, Texas on March 10, 1980. This report describes the findings of a team of Texas A and M University scientists and engineers who have conducted a study to evaluate the effects of the Bryan Mound brine discharge on the marine environment. The study addresses the areas of physical oceanography, analysis of the discharge plume, water and sediment quality, nekton, benthos, and data management. It focuses on the period from September 1981 through August 1982. Volume II contains appendices for: (1) supporting data for physical oceanography; (2) supporting data for analysis of the discharge plume; (3) supporting data for water and sediment quality; (4) supporting data for nekton studies; and (5) Bryan Mound discharge data.

  3. Evaluation of brine disposal from the Bryan Mound site of the Strategic Petroleum Reserve program. Final report of 18 month postdisposal studies

    SciTech Connect

    Chittenden, M.E. Jr.; Cummings, J.A.; Harper, D.E. Jr.

    1982-03-01

    The Department of Energy's Strategic Petroleum Reserve Program began leaching the Bryan Mound salt dome and discharging brine into the coastal waters of Freeport, Texas on March 10, 1980. This report describes the findings of a team of Texas A and M University scientists and engineers who have conducted an eighteen-month environmental study to evaluate the effects of the Bryan Mound brine discharge. The study addresses the areas of physical oceanography, analysis of the discharge plume, water and sediment quality, nekton, benthos, phytoplankton, zooplankton, and data management.

  4. Plutonium working group report on environmental, safety and health vulnerabilities associated with the Department`s plutonium storage. Volume II, part 7: Mound working group assessment team report

    SciTech Connect

    1994-09-01

    This is the report of a visit to the Mound site by the Working Group Assessment Team (WGAT) to assess plutonium vulnerabilities. Purposes of the visit were: to review results of the site`s self assessment of current practices for handling and storing plutonium; to conduct an independent assessment of these practices; to reconcile differences and assemble a final list of vulnerabilities; to calculate consequences and probability for each vulnerability; and to issue a report to the Working Group. This report, representing completion of the Mound visit, will be compiled along with those from all other sites with plutonium inventories as part of a final report to the Secretary of Energy.

  5. Microbial assemblages on a cold-water coral mound at the SE Rockall Bank (NE Atlantic): interactions with hydrography and topography

    NASA Astrophysics Data System (ADS)

    van Bleijswijk, J. D. L.; Whalen, C.; Duineveld, G. C. A.; Lavaleye, M. S. S.; Witte, H. J.; Mienis, F.

    2015-01-01

    This study shows the microbial community composition over Haas Mound, one of the most prominent cold-water coral mounds of the Logachev Mound Province (Rockall Bank, NE Atlantic), outlining distribution patterns both vertically from the seafloor to the water column and laterally across the mound and coupling this to mound topography and hydrography. Samples were collected in 2012 and 2013 from biotopes that were partially chosen based on high definition video surveys that were conducted prior to sampling and included overlaying water (400 m depth and 5+10 m above the bottom (m ab)) collected with a CTD/Rosette system and near-bottom water, sediment, Lophelia pertusa mucus, and L. pertusa skeleton samples collected with a box-core. Furthermore, temperature and current measurements were obtained at two sites at the summit and foot of Haas Mound to study near-bed hydrodynamic conditions. Community composition was determined by next generation Roche 454 sequencing yielding high-resolution records of 16 S rRNA genotypes, improving our understanding of deep-sea microbial consortia. With the methods we employed we were able to report for the first time Archaea in association with L. pertusa. The pattern of similarities between samples visualized by multi-dimensional scaling (MDS), indicates a strong link between the distribution of microbes and specific biotopes. All biotopes share a number of taxa, but biotopes are distinct on basis of relative abundances and a small number of unique taxa. Similarity in microbes indicates that water is well-mixed at 400 m depth, but less so at 5 + 10 m above the bottom, where microbial communities differed between summit, slope and off mound. Even more variability was observed in the near-bottom water samples, which group according to sampling station. Likely the coral framework prevents the near-bottom water in between the branches to be vigorously mixed with the water overlaying the reef. The microbial consortium on Haas Mound appears

  6. Feedbacks between flow, sediment motion and microbial growth on sand bars initiate and shape elongated stromatolite mounds

    NASA Astrophysics Data System (ADS)

    Mariotti, G.; Perron, J. T.; Bosak, T.

    2014-07-01

    Elongated stromatolites are often used as indicators of current direction and shoreline orientation, especially in paleoenvironmental reconstructions. However, mechanisms that create shore-parallel, m-scale elongated stromatolite mounds in carbonate sand are not well understood. We propose that this geometry is initiated by microbial growth on the parts of sand bars that experience low wave-induced bed shear stresses. We test this idea by growing microbial mats on carbonate sand bars in a laboratory wave tank. Cyanobacterial mats grow on the bar runnels, where sediment motion is negligible, but are absent from the bar ridges, where the waves generate migrating ripples. When microbially-promoted lithification reinforces and preserves this initial pattern, elongated stromatolites should initiate in the runnels of sand bars, with long wavelengths (5-100 m) and small width-to-wavelength ratios (∼0.3). These dimensions are consistent with modern shore-parallel stromatolites in Hamelin Pool, Western Australia, and with patterns of microbial colonization in other sandy sediments. This model of elongated stromatolite mounds can inform paleoenvironmental reconstructions by clarifying and quantifying feedbacks among waves, sediment transport and microbial growth.

  7. Evaluation of brine disposal from the Bryan Mound site of the strategic petroleum reserve program. Final report

    SciTech Connect

    Case, Robert J.; Chittenden, Jr, Mark E.; Harper, Jr, Donald E.; Kelly, Jr, Francis J.; Loeblich, Laurel A.; McKinney, Larry D.; Minello, Thomas J.; Park, E. Taisoo; Randall, Robert E.; Slowey, J. Frank

    1981-01-01

    On March 10, 1980, the Department of Energy's Strategic Petroleum Reserve Program began leaching the Bryan Mound salt dome and discharging the resulting brine into the coastal waters off Freeport, Texas. During the months of March and April, a team of scientists and engineers from Texas A and M University conducted an intensive environmental study of the area surrounding the diffuser site. A pipeline has been laid from the Bryan Mound site to a location 12.5 statute miles (20 km) offshore. The last 3060 ft (933 m) of this pipeline is a 52-port diffuser through which brine can be discharged at a maximum rate of 680,000 barrels per day. Initially, 16 ports were open which permitted a maximum discharge rate of 350,000 barrels per day and a continuous brine discharge was achieved on March 13, 1980. The purpose of this report is to describe the findings of the project team during the intensive postdisposal study period of March and April, 1980. The major areas of investigation are physical oceanography, analysis of the discharge plume, water and sediment quality, nekton, benthos, phytoplankton, zooplankton, and data management.

  8. Sand remobilization enhanced complexity to mounded geometry, Early Tertiary deep water sand reservoirs, Balder Oil Field North Sea

    SciTech Connect

    Bergslien, D.; Rye-Larsen, M.; Jenssen, A.I.

    1996-12-31

    Sand remobilization played a major role in generating the high relief mounded geometries that trap oil in the early Tertiary reservoirs at Balder Field in Norwegian North Sea blocks 25/10 and 25/11. The thick massive submarine-fan sandstones were shed from the East Shetland Platform and deposited from high density turbidity currents. These thick massive sandstones lie in the distal portions of the fan system on the northwestern margin of the Utsira High. An intricate interaction between deposition and soft sediment deformation processes generated the complex cluster of thick mounded sand geometries comprising the Balder oil field. Slumping, sliding and sand remobilization with associated sand injections into overlying shales were the dominant deformation processes that mainly occurred during the early Eocene. The field is comprised of three reservoirs, the Paleocene Heimdal and Hermod Formations and the Early Eocene Balder Formation. The sandstones, which have excellent reservoir properties, share a common pressure system and oil-water contact. This is probably related to the soft-sediment deformation and associated sand injections establishing cross-stratal communication.

  9. Sand remobilization enhanced complexity to mounded geometry, Early Tertiary deep water sand reservoirs, Balder Oil Field North Sea

    SciTech Connect

    Bergslien, D.; Rye-Larsen, M.; Jenssen, A.I. )

    1996-01-01

    Sand remobilization played a major role in generating the high relief mounded geometries that trap oil in the early Tertiary reservoirs at Balder Field in Norwegian North Sea blocks 25/10 and 25/11. The thick massive submarine-fan sandstones were shed from the East Shetland Platform and deposited from high density turbidity currents. These thick massive sandstones lie in the distal portions of the fan system on the northwestern margin of the Utsira High. An intricate interaction between deposition and soft sediment deformation processes generated the complex cluster of thick mounded sand geometries comprising the Balder oil field. Slumping, sliding and sand remobilization with associated sand injections into overlying shales were the dominant deformation processes that mainly occurred during the early Eocene. The field is comprised of three reservoirs, the Paleocene Heimdal and Hermod Formations and the Early Eocene Balder Formation. The sandstones, which have excellent reservoir properties, share a common pressure system and oil-water contact. This is probably related to the soft-sediment deformation and associated sand injections establishing cross-stratal communication.

  10. Geomorphology: Quake, rubble and roll

    NASA Astrophysics Data System (ADS)

    Niemi, Nathan A.

    2014-12-01

    Temporal variations in coarse river deposits are often attributed to climate change. Cosmogenic nuclide concentrations of river cobbles suggest that climate plays a subordinate role to earthquake-induced landslides in producing coarse sediments in arid Peru.

  11. Greenhouse gas exchange in West African savanna ecosystems - how important are emissions from termite mounds?

    NASA Astrophysics Data System (ADS)

    Brümmer, C.; Brüggemann, N.

    2012-04-01

    Savannas cover large areas of the Earth's surface and play an important role in global carbon and nitrogen cycling. In this study, we present the soil-atmosphere exchange of N2O, CH4, and CO2 during two field campaigns throughout the growing seasons 2005 and 2006 at a natural savanna site that was not subject to human disturbances except for annual burning, and four agricultural sites planted with sorghum (n=2), cotton and peanut in Burkina Faso. The annual N2O emission of the nature reserve site amounted to 0.52 kg N2O-N ha-1 yr-1 in 2005 and to 0.67 kg N2O-N ha-1 yr-1 in 2006, whereas the calculated average annual N2O release of the crop sites was only 0.19 and 0.20 kg N2O-N ha-1 yr-1 in 2005 and 2006, respectively. As a result of a temporal up-scaling approach, a lower bound of annual N2O release could be given for two fertilized sorghum plots, that is, 0.83 kg N2O-N ha-1 yr-1 for a highly fertilized plot and 0.44 kg N2O-N ha-1 yr-1 for a moderately fertilized plot. During the rainy season both CH4 uptake in the range of up to 20 μg CH4-C m-2 h-1 as well as CH4 emission up to 300 μg CH4-C m-2 h-1 were observed at the nature reserve site, which was on average a CH4 source of 87.4 and 30.8 μg CH4-C m-2 h-1 in 2005 and 2006, respectively. All crop sites were on average weak CH4 sinks without significant seasonal variation. Uptake rates ranged between 2.5 and 8.7 μg CH4-C m-2 h-1. Occasionally very low net CH4 emission was observed after heavy rainfall events. Mean annual CH4 rates could be estimated to 2.48 kg CH4-C ha-1 yr-1 and -0.68 kg CH4-C ha-1 yr-1 for the nature reserve site and the crop sites, respectively. Trace gas emissions from termite (Cubitermes fungifaber) mounds that were almost exclusively found at the nature reserve were one order of magnitude higher for N2O and CO2, and two orders of magnitude higher for CH4 than soil emissions of the respective trace gas. Termite N2O, CH4 and CO2 release at the nature reserve contributed only 3.2%, 8.1% and

  12. Mortality among mound workers exposed to polonium-210 and other sources of radiation, 1944-1979.

    PubMed

    Boice, John D; Cohen, Sarah S; Mumma, Michael T; Ellis, Elizabeth Dupree; Cragle, Donna L; Eckerman, Keith F; Wallace, Phillip W; Chadda, Bandana; Sonderman, Jennifer S; Wiggs, Laurie D; Richter, Bonnie S; Leggett, Richard W

    2014-02-01

    Polonium-210 is a naturally occurring radioactive element that decays by emitting an alpha particle. It is in the air we breathe and also a component of tobacco smoke. Polonium-210 is used as an anti-static device in printing presses and gained widespread notoriety in 2006 after the poisoning and subsequent death of a Russian citizen in London. More is known about the lethal effects of polonium-210 at high doses than about late effects from low doses. Cancer mortality was examined among 7,270 workers at the Mound nuclear facility near Dayton, OH where polonium-210 was used (1944-1972) in combination with beryllium as a source of neutrons for triggering nuclear weapons. Other exposures included external gamma radiation and to a lesser extent plutonium-238, tritium and neutrons. Vital status and cause of death was determined through 2009. Standardized mortality ratios (SMRs) were computed for comparisons with the general population. Lifetime occupational doses from all places of employment were sought and incorporated into the analysis. Over 200,000 urine samples were analyzed to estimate radiation doses to body organs from polonium and other internally deposited radionuclides. Cox proportional hazards models were used to evaluate dose-response relationships for specific organs and tissues. Vital status was determined for 98.7% of the workers of which 3,681 had died compared with 4,073.9 expected (SMR 0.90; 95% CI 0.88-0.93). The mean dose from external radiation was 26.1 mSv (maximum 939.1 mSv) and the mean lung dose from external and internal radiation combined was 100.1 mSv (maximum 17.5 Sv). Among the 4,977 radiation workers, all cancers taken together (SMR 0.86; 95% CI 0.79-0.93), lung cancer (SMR 0.85; 95% CI 0.74-0.98), and other types of cancer were not significantly elevated. Cox regression analysis revealed a significant positive dose-response trend for esophageal cancer [relative risk (RR) and 95% confidence interval at 100 mSv of 1.54 (1.15-2.07)] and a

  13. Maize Storage in Termite Mound Clay, Concrete, and Steel Silos in the Humid Tropics: Comparison and Effect on Bacterial and Fungal Counts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study investigated the functional suitability of using the readily-available termite mound clay (TMC) for grain silo construction in comparison to conventional reinforced concrete (RC) and galvanized steel (GS) silos for maize storage in the humid tropics. The extent to which temperature and r...

  14. Performance evaluation of termite-mound clay, concrete and steel silos for the storage of maize grains in the humid tropics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inadequate storage facilities have contributed to severe maize postharvest losses in many developing countries. This study determined the potential of termite mound clay (TMC), a readily-available material in Nigeria, as a construction material for storage silos. The performance of the TMC silo was ...

  15. Microbial assemblages on a cold-water coral mound at the SE Rockall Bank (NE Atlantic): interactions with hydrography and topography

    NASA Astrophysics Data System (ADS)

    van Bleijswijk, J. D. L.; Whalen, C.; Duineveld, G. C. A.; Lavaleye, M. S. S.; Witte, H. J.; Mienis, F.

    2015-07-01

    This study characterizes the microbial community composition over Haas Mound, one of the most prominent cold-water coral mounds of the Logachev Mound province (Rockall Bank, NE Atlantic). We outline patterns of distribution vertically - from the seafloor to the water column - and laterally - across the mound - and couple these to mound topography and hydrography. Samples of water, sediment and Lophelia pertusa were collected in 2012 and 2013 from locations that were chosen based on high definition video surveys. Temperature and current measurements were obtained at two sites at the summit and foot of Haas Mound to study near-bed hydrodynamic conditions. Overlaying water was collected from depths of 400 m as well as 5 and 10 m above the bottom using a CTD/Rosette system. Near-bottom water, sediment and L. pertusa mucus and skeleton samples were obtained with a box corer. Of all these biotopes, Roche GS-FLX amplicon sequencing targeting both Bacteria and Archaea was carried out, augmenting our understanding of deep sea microbial consortia. The pattern of similarities between samples, visualized by multi-dimensional scaling (MDS), indicates a strong link between the distribution of microbes and the specific biotopes. The microbial operational taxonomic unit (OTU) diversity was the highest in near-bottom water, which was sampled in the coral framework. For the first time, Thaumarchaeota marine group I (MGI) were found in L. pertusa mucus; Endozoicomonas was detected in skeleton, mucus and near-bottom water, whereas Mycoplasma was only detected in skeleton and near-bottom water, however not in mucus. Analysis of similarities (ANOSIM) indicates that overlaying water is well-mixed at 400 m depth but less so at 5 and 10 m above the bottom, where the composition of microbial communities differed significantly between summit, slope and off-mound. At all locations, the near-bottom water differed significantly from water at 5 m above the bottom, illustrating that the near

  16. Mineralogy of Juventae Chasma: Sulfates in the light-toned mounds, mafic minerals in the bedrock, and hydrated silica and hydroxylated ferric sulfate on the plateau

    NASA Astrophysics Data System (ADS)

    Bishop, Janice L.; Parente, Mario; Weitz, Catherine M.; Noe Dobrea, Eldar Z.; Roach, Leah H.; Murchie, Scott L.; McGuire, Patrick C.; McKeown, Nancy K.; Rossi, Christopher M.; Brown, Adrian J.; Calvin, Wendy M.; Milliken, Ralph; Mustard, John F.

    2009-11-01

    Juventae Chasma contains four light-toned sulfate-bearing mounds (denoted here as A-D from west to east) inside the trough, mafic outcrops at the base of the mounds and in the wall rock, and light-toned layered deposits of opal and ferric sulfates on the plateau. Hyperspectral visible/near-infrared Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) spectra were used to identify monohydrated and polyhydrated sulfate (PHS) outcrops of layered material on the bright mounds. Most of the monohydrated sulfate signatures closely resemble those of szomolnokite (FeSO4·H2O), characterized by a water band near 2.08 μm, while some areas exhibit spectral features more similar to those of kieserite (MgSO4·H2O), with a band centered closer to 2.13 μm. The largest PHS outcrops occur on the top of mound B, and their spectral features are most consistent with ferricopiapite, melanterite, and starkeyite, but a specific mineral cannot be uniquely identified at this time. Coordinated analyses of CRISM maps, Mars Orbiter Laser Altimeter elevations, and High Resolution Imaging Science Experiment images suggest that mounds A and B may have formed together and then eroded into separate mounds, while mounds C and D likely formed separately. Mafic minerals (low-Ca pyroxene, high-Ca pyroxene, and olivine) are observed in large ˜2-10 km wide outcrops in the wall rock and in smaller outcrops ˜50-500 m across at the floor of the canyon. Most of the wall rock is covered by at least a thin layer of dust and does not exhibit strong features characteristic of these minerals. The plateau region northwest of Juventae Chasma is characterized by an abundance of light-toned layered deposits. One region contains two spectrally unique phases exhibiting a highly stratified, terraced pattern. CRISM spectra of one unit eroded into swirling patterns with arc-like ridges exhibit a narrow 2.23-μm band assigned to hydroxylated ferric sulfate. A thin layer of a fractured material bearing an

  17. Synsedimentary tectonics, mud-mounds and sea-level changes on a Palaeozoic carbonate platform margin: a Devonian Montagne Noire example (France)

    NASA Astrophysics Data System (ADS)

    Bourrouilh, Robert; Bourque, Pierre-André; Dansereau, Pauline; Bourrouilh-Le Jan, Françoise; Weyant, Pierre

    1998-06-01

    The Devonian sedimentary succession of the southern flank of the Montagne Noire (France) was deposited along a divergent margin. This paper is a contribution to describe and evaluate biogenic, sedimentary, geochemical and micropalaeontological features as indicators of sea-level changes and global history of the Devonian in this area. Following transgression and shallow-water environments during Early Devonian time (Lochkovian to early Emsian), biogenic mud-rich mounds with stromatactis developed during latest Emsian at the platform margin. The depth of the Devonian sea was increasing and the seafloor passed below the photic zone and the lower limit of storm wave base during the Emsian. Growth and seismic faults affected the mounds and created Neptunian cracks and crevices, quickly filled with sedimentary material (pisoids) and cements (Neptunian dykes and veins). Light and CL-microscopy, and stable isotope geochemistry show that stromatactis, cements of Neptunian dykes, veins and pisoid cortices are early marine, whereas the red finely crystalline material that forms the bulk of the mound has been cemented in the near-surface diagenetic environment, after the early marine cementation of stromatactis and Neptunian dykes and veins, by meteoric or hydrothermal fluids. The sedimentary rocks overlying the stromatactis mounds exhibit regularly condensed iron and manganese-rich layers, interrupted by the Kellwasser hypoxic horizon. These condensed deposits developed up to the Famennian in a context of carbonate gravity sedimentation and became more and more rhythmic and frequent up section. The occurrence and irregular distribution of large-scale submarine mass flows during Frasnian and Famennian times can be related to block faulting on which Lower Devonian stromatactis mounds could have been uplifted by this block faulting to form seamounts. The sea-level fluctuations detected in the southern flank of Montagne Noire are compared to the Devonian eustatic sea-level curve

  18. The Guaymas Basin Hiking Guide to Hydrothermal Mounds, Chimneys, and Microbial Mats: Complex Seafloor Expressions of Subsurface Hydrothermal Circulation

    PubMed Central

    Teske, Andreas; de Beer, Dirk; McKay, Luke J.; Tivey, Margaret K.; Biddle, Jennifer F.; Hoer, Daniel; Lloyd, Karen G.; Lever, Mark A.; Røy, Hans; Albert, Daniel B.; Mendlovitz, Howard P.; MacGregor, Barbara J.

    2016-01-01

    The hydrothermal mats, mounds, and chimneys of the southern Guaymas Basin are the surface expression of complex subsurface hydrothermal circulation patterns. In this overview, we document the most frequently visited features of this hydrothermal area with photographs, temperature measurements, and selected geochemical data; many of these distinct habitats await characterization of their microbial communities and activities. Microprofiler deployments on microbial mats and hydrothermal sediments show their steep geochemical and thermal gradients at millimeter-scale vertical resolution. Mapping these hydrothermal features and sampling locations within the southern Guaymas Basin suggest linkages to underlying shallow sills and heat flow gradients. Recognizing the inherent spatial limitations of much current Guaymas Basin sampling calls for comprehensive surveys of the wider spreading region. PMID:26925032

  19. The Guaymas Basin Hiking Guide to Hydrothermal Mounds, Chimneys, and Microbial Mats: Complex Seafloor Expressions of Subsurface Hydrothermal Circulation.

    PubMed

    Teske, Andreas; de Beer, Dirk; McKay, Luke J; Tivey, Margaret K; Biddle, Jennifer F; Hoer, Daniel; Lloyd, Karen G; Lever, Mark A; Røy, Hans; Albert, Daniel B; Mendlovitz, Howard P; MacGregor, Barbara J

    2016-01-01

    The hydrothermal mats, mounds, and chimneys of the southern Guaymas Basin are the surface expression of complex subsurface hydrothermal circulation patterns. In this overview, we document the most frequently visited features of this hydrothermal area with photographs, temperature measurements, and selected geochemical data; many of these distinct habitats await characterization of their microbial communities and activities. Microprofiler deployments on microbial mats and hydrothermal sediments show their steep geochemical and thermal gradients at millimeter-scale vertical resolution. Mapping these hydrothermal features and sampling locations within the southern Guaymas Basin suggest linkages to underlying shallow sills and heat flow gradients. Recognizing the inherent spatial limitations of much current Guaymas Basin sampling calls for comprehensive surveys of the wider spreading region. PMID:26925032

  20. Interdisciplinary landscape research in a medieval mound in one of the oldest Dutch towns, Vlaardingen, the Netherlands

    NASA Astrophysics Data System (ADS)

    de Ridder, Tim; Kluiving, Sjoerd; van Dasselaar, Marcel

    2013-04-01

    In Medieval times the city of Vlaardingen (the Netherlands) was strategically located on the confluence of three rivers, the Meuse, the Merwede and the Vlaarding. A church of early 8th century was already located here. In a short period of time Vlaardingen developed into an international trading place, the most important place in the former county of Holland. Starting from the 11th century the river Meuse threatened to flood the settlement, and as a reaction to it inhabitants started to raise the surface. This resulted eventually in an enormous mound, surface: 200 by 250 meter, built up in a four to five meter thick sequence of clay and manure in which organic rests of former occupation are extremely well preserved, e.g. wooden posts, mesh walls, but also leather objects. Early 2002 graves were found in the c