http://hdl.handle.net/1957/1309 http://ir.library.oregonstate.edu/dspace/retrieve/5801 http://hdl.handle.net/1957/1309 Search the Channel search http://ir.library.oregonstate.edu/dspace/simple-search http://hdl.handle.net/1957/9441 Title: Mapping and lithologic interpretation of the Territorial Sea, Oregon <br/> <br/>Abstract: Seafloor lithologic maps have been widely used to identify conservation sites. In this study, a lithologic interpretation of Oregon's territorial seafloor was created as an interim product in response to the need for a comprehensive lithologic map that will be used in the identification, evaluation and design of marine reserves in Oregon. While future multibeam mapping of the Oregon Territorial Sea will likely replace this product in the next few years, the ground truth data from which the map is constructed will continue in use in future efforts. This mapping project utilized a classical geologic approach aided by GIS technology in which all relevant thematic geologic layers were applied to interpret patterns of seafloor lithology. The discovery of approximately 9,600 NOS bottom samples from the National Ocean Service (NOS) historic hydrographic smooth sheet archives has tremendously improved upon the original sample dataset (305 bottom samples) used in previous characterization of Oregon's territorial seabed. Supplementing the NOS bottom samples, other existing datasets including historic kelp distribution (used as proxy for rock), a triangulated irregular network (TIN) surface model derived from bathymetric soundings, rock outcrops digitized from 0.5 meter aerial photos, subsurface structure, and the adjacent onshore Oregon digital geologic map were used. While the collection of smooth sheet data from historic surveys utilized leadline sampling techniques and traditional navigation methods such as three-point sextant positioning, it was observed that the typical positional error averaged ~28 meters relative to contemporary aerial photography where comparison was possible. GIS software was used for simultaneous display of varied thematic layers, qualitative interpretation, quantitative accuracy assessment, and density mapping processes in this project. This current mapping effort showed that the NOS "smooth sheet" data collected from 1858 to 1958 compares well with modern data and that the NOS datasets and methods are able to capture the general outlines of rocky outcrops particularly in shallow areas. The territorial lithologic map shows a reasonable overall accuracy of 64 % relative to existing habitat interpretation of rocky reefs based on high-resolution multibeam data. Furthermore, the NOS bottom samples provide an opportunity to map additional sediment types that are not represented in the existing Surficial Geologic Habitat (SGH) map of the territorial sea. Finally, a companion product to the maps, a composite density map was created from the underlying datasets (kelp, bathymetry and bottom samples) to represent the spatial variation in data quality and quantity used in the interpretation of seafloor lithology. It is anticipated that the data obtained from this study will serve as a useful tool for scientific investigation and management efforts such as the ocean zoning in the nearshore region of the Oregon coast, which includes the upcoming designation and evaluation of marine reserves. <br/> <br/>Description: Graduation date: 2009 Fri, 26 Sep 2008 19:02:24 GMT http://hdl.handle.net/1957/9257 Title: Oceanography in 2028 <br/> <br/>Abstract: This article considers the evolutionary pressures that have brought us to our present state and how these forces will likely change, with a focus on U.S. institutional structures. Fri, 29 Aug 2008 22:58:59 GMT http://hdl.handle.net/1957/9171 Title: Cenozoic biogenic silica sedimentation in the Antarctic Ocean, based on two deep sea drilling project sites <br/> <br/>Abstract: The Antarctic Ocean during the Cenozoic experienced four periods of increased surface productivity: the Middle Eocene; the beginning of the Miocene; the Middle Miocene; and near the Miocene-Pliocene boundary. The fourth increase in productivity began five million years ago and has since progressively increased to the present level of intense surface productivity. The major control of Antarctic surface productivity is climate. Opal production in the Neogene increased during glacial times, due to the intensification of upwelling south of the Polar Front, caused from accelerated atmospheric circulation and an increased volume production of Antarctic Bottom Water. Cenozoic variations in surface productivity are also related to the tectonic changes in the Antarctic Ocean basin, which altered the patterns of surface and thermohaline circulation. Antarctic Surface Waters became more conducive to biological productivity with the progressive latitudinal and thermal isolation of Antarctica, The efficiency of surface productivity has progressed to such an extent that much of the global silica supply has been transferred to the Antarctic at the expense of other productive oceanic regions such as the Central Equatorial Pacific. In the Neogene, the preservation or dissolution of calcium carbonate is influenced by the rate of upwelling south of the Polar Front. During glacial times, the upwelling of COB_rich Circumpolar Deep Water accelerates and effectively raises the calcite compensation depth. <br/> <br/>Description: Graduation date: 1977; Presentation date: 1977-04-21 Wed, 20 Apr 1977 22:58:59 GMT http://hdl.handle.net/1957/9169 Title: The role of stridulation in the behavior of the shore crab Hemigrapsus oregonensis <br/> <br/>Abstract: The claw shuddering display of the shore crab Hemigrapsus oregonensis was explored with acoustic and behavioral observations. Male H. oreqonensis stridulate during claw shuddering display. The stridulatory apparatus is present only on the males. The acoustic signal was of brief duration, showed a general pattern of sound bursts, but varied among individual crabs. The larger crabs produced more intense signals. Because H. oreqonensis live in a turbid water of a mud-rock habitat or in burrows of the estuary, acoustic communication is well suited to their environment. Behavioral observations of H. oregonensis, collected from Yaquina Bay, Oregon, were made in habitat replicas of the mud-rock environment. Stridulation by male crabs was elicited equally by male and female crabs but the amount of stridulation increased when all the crabs were males. The strldulat,ing crab was typically maintaining a territory and did not retreat after signaling. The significance of stridulation in the total repertoire has not been resolved but territoriality as exemplified by burrow defense and communication facilitating ritualization have been indicated, and its importance in sexual behavior has not been demonstrated. <br/> <br/>Description: Graduation date: 1978; Presentation date: 1977-08-25 Wed, 24 Aug 1977 22:58:59 GMT