6 resultados para submarine channels
em Aquatic Commons
Resumo:
During a 25-hour hydrographic times series at two stations near the head of Monterey Submarine Canyon, an internal tide was observed with an amplitude of 80 to 115 m in water depths of 120 and 220 m respectively. These large oscillations produced daily variations in hydrographic and chemical parameters that were of the same magnitude as seasonal variations in Monterey Bay. Computed velocities associated with the internal tide were on the order of 10 em/sec, and this tidally induced circulation may have a significant role in the exchange of deep water between Monterey Submarine Canyon and the open ocean. (PDF contains 49 pages)
Resumo:
Submarine Landslides: An Introduction 1 By RIo Lee, W.C. Schwab, and J.S. Booth U.S. Atlantic Continental Slope Landslides: Their Distribution, General Anributes, and Implications 14 By J.S. Booth, D.W. O'Leary, Peter Popenoe, and W.W. Danforth Submarine Mass Movement, a Formative Process of Passive Continental Margins: The Munson-Nygren Landslide Complex and the Southeast New England Landslide Complex 23 By D.W. O'Leary The Cape Fear Landslide: Slope Failure Associated with Salt Diapirism and Gas Hydrate Decomposition 40 By Peter Popenoe, E.A. Schmuck, and W.P. Dillon Ancient Crustal Fractures Control the Location and Size of Collapsed Blocks at the Blake Escarpment, East of Florida 54 By W.P. Dillon, J.S. Risch, K.M. Scanlon, P.C. Valentine, and Q.J. Huggett Tectonic and Stratigraphic Control on a Giant Submarine Slope Failure: Puerto Rico Insular Slope 60 By W.C. Schwab, W.W. Danforth, and K.M. Scanlon Slope Failure of Carbonate Sediment on the West Florida Slope 69 By D.C. Twichell, P.C. Valentine, and L.M. Parson Slope Failures in an Area of High Sedimentation Rate: Offshore Mississippi River Delta 79 By J.M. Coleman, D.B. Prior, L.E. Garrison, and H.J. Lee Salt Tectonics and Slope Failure in an Area of Salt Domes in the Northwestern Gulf of Mexico 92 By B.A. McGregor, R.G. Rothwell, N.H. Kenyon, and D.C. Twichell Slope Stability in Regions 01 Sea-Floor Gas Hydrate: Beaufort Sea Continental Slope 97 By R.E. Kayen and H.J. Lee Mass Movement Related to Large Submarine Canyons Along the Beringian Margin, Alaska 104 By P.R. Carlson, H.A. Karl, B.D. Edwards, J.V. Gardner, and R. Hall Comparison of Tectonic and Stratigraphic Control of Submarine Landslides on the Kodiak Upper Continental Slope, Alaska 117 By M.A. Hampton Submarine Landslides That Had a Significant Impact on Man and His Activities: Seward and Valdez, Alaska 123 By M.A. Hampton, R.W. Lemke, and H.W. Coulter Processes Controlling the Style of Mass Movement in Glaciomarine Sediment: Northeastern Gulf of Alaska 135 By W.C. Schwab and H.J. Lee Contents V VI Contents Liquefaction of Continental Shelf Sediment: The Northern California Earthquake of 1980 143 By M.E. Field A Submarine Landslide Associated with Shallow Sea-Floor Gas and Gas Hydrates off Northern California 151 By M.E. Field and J.H. Barber, Jr. Sur Submarine Landslide, a Deep-Water Sediment Slope Failure 158 By C.E. Gutmacher and W.R. Normark Seismically Induced Mudflow in Santa Barbara Basin, California 167 By B.D. Edwards, H.J. Lee, and M.E. Field Submarine Landslides in a Basin and Ridge Setting, Southern California 176 By M.E. Field and B.D. Edwards Giant Volcano-Related Landslides and the Development of the Hawaiian Islands 184 By W.R. Normark, J.G. Moore, and M.E. Torresan Submarine Slope Failures Initiated by Hurricane Iwa, Kahe Point, Oahu, Hawaii 197 By W.R. Normark, Pat Wilde, J.F. Campbell, T.E. Chase, and Bruce Tsutsui (PDF contains 210 pages)
Resumo:
The design and construction of four experimental channels at Grassholme reservoir in Teesdale, County Durham (UK) are briefly described. The problem of obtaining valid replication between channels is examined using published data obtained for previous experiments in the channels. It is concluded that replication may be obtained by careful experimental design. The limitations of the existing configuration of pipework and channel design are discussed and solutions suggested. Finally a list of the main components of the channels and suppliers is appended. Alternative materials and suppliers could well be found for most items. (PDF contains 23 pages)
Resumo:
Adjustment of experimental channels to give any specified pattern of water depth or velocity is complex and tedious because it involves a number of variables. Since some variables are not controllable and variables may interact, valve settings of the Grassholme channels were initially determined on an ad hoc basis to suit individual experiments. This method was used during 1982 but additional observations were made in order to gain more detailed understanding of the channel system and, as far as possible, to develop a guide to future short-cuts in attaining suitable channel settings for any given purpose. This report describes calibration of the Grassholme channels (using water of the Grassholme Reservoir) for the biological experiments of spring - summer 1982. The main variables that are discussed are valve turns and discharge and velocity and depth. It also seeks to establish relationships which will be of value in future managment of the channels for experimental purposes.
Resumo:
A number of authors have described the manner in which young salmonids, soon after emergence from the gravel, set up and defend territories. This leads to mortality or downstream displacement of the individuals which are unable to acquire territories and is widely accepted as the main method of population regulation amongst young salmonids. In some field experiments the fish were constrained in screened reaches and the option of downstream dispersal for the surplus fry was thus excluded. In order to explore some aspects of downstream dispersal more closely under conditions which gave more control than is obtained in a natural stream, four experimental channels were set up at Grassholme reservoir in Teesdale. The report describes the results of investigations on the timing and rate of downstream movement of young brown trout (Salmo trutta L.) and Atlantic salmon (Salmo salar L.) out of experimental channels, with special reference to the effect of water velocity on the rate of ”emigration”.
Resumo:
In August and September of 1997 and 1998, we used SCUBA techniques to surgically implant Vemco V16 series acoustic transmitters in 6 greenspotted rockfish (Sebastes chlorostictus) and 16 bocaccio (S. paucispinis) on the flank of Soquel Canyon in Monterey Bay, California. Fish were captured at depths of 100–200 m and reeled up to a depth of approximately 20 m, where a team of SCUBA divers anesthetized and surgically implanted acoustic transmitters in them. Tagged fish were released on the seafloor at the location of catch. An array of recording receivers on the seafloor enabled the tracking of horizontal and vertical fish movements for a three-month period. Greenspotted rockfish tagged in 1997 exhibited almost no vertical movement and showed limited horizontal movement. Two of these tagged fish spent more than 90% of the time in a 0.58-km2 area. Three other tagged greenspotted rockfish spent more than 60% of the time in a 1.6-km2 area but displayed frequent horizontal movements of at least 3 km. Bocaccio exhibited somewhat greater movements. Of the 16 bocaccio tagged in 1998, 10 spent less than 10% of the time in the approximately 12-km2 study area. One fish stayed in the study area for about 50% of the study time. Signals from the remaining 5 fish were recorded in the study area the entire time. Bocaccio frequently moved vertically 10–20 m and occasionally displayed vertical movements of 100 m or greater.