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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Systematics and palaeobiology of the crested hadrosaurine Saurolophus from Canada and Mongolia

Bell, Phil Unknown Date
No description available.
192

Spatial and temporal distribution of sperm whales (Physeter macrocephalus) within the Kaikoura submarine canyon in relation to oceanographic variables

Sagnol, Ophélie Julie Yolaine January 2014 (has links)
The Kaikoura area is a valuable feeding spot for sperm whales with the presence of a submarine canyon close to shore. Male sperm whales can be found there year around, close to the shore and exhibiting almost constant foraging activities. This thesis investigates the distribution and habitat use, both spatially and temporally, of sperm whales (Physeter macrocephalus) within the Kaikoura submarine canyon, New Zealand. The primary aim was to determine which oceanographic variables and bathymetric features influence the sperm whale distribution patterns off Kaikoura. A theodolite was used to track surfacing and movement of sperm whales from a shore-based station. The accuracy of positions recorded by the theodolite was investigated by comparing theodolite measurements of an object of known position. A calibration technique was then developed as the vertical angle was not accurately determined by the theodolite. In addition to investigating the distribution of sperm whales, the daily abundance of sperm whales within the Kaikoura submarine canyon was estimated. Distance sampling and mark-resight models showed an average of 4 (SEM = 0.13) individuals present in the study area at any given time. The mark-resight technique using photo-identification was not possible from a shore-based station so a spatio-temporal model was built in order to track the identity of individuals. The model was tested using photo-identification of sperm whales collected from a boat-based station. Results showed that 88% of the modeled identifications corresponded to the photo-identification database. Sperm whales off Kaikoura were strongly associated with depth, slope and distance from the nearest coast. They were found in waters between 500 m to 1250 m deep and preferred shallower waters in winter. In spring, sperm whales occurred further from the coast, mainly in the Hikurangi Trough, north-east of the shore-based station. Generalized Additive Models (GAM) were used to identify significant oceanographic variables predicting the presence of sperm whales off Kaikoura. Models indicated that sea surface temperature (SST), chlorophylla (Chla) and distance from sea surface temperature fronts were all important parameters in predicting sperm whales presence. Results showed that sperm whales aggregated in the section of the study area with the lowest SST and near SST fronts. This study provides a detailed insight into the use of the Kaikoura submarine canyon by male sperm whales.
193

Simulating the effects of dam releases on Grand Canyon river trips

Borkan, Ronald E., January 1986 (has links) (PDF)
Thesis (M.S. - Renewable Natural Resources)--University of Arizona, 1986. / Includes bibliographical references (leaves 78-80).
194

Training leaders for the Lifegroup ministry of the University Church of Christ, Canyon, Texas

Lough, David. January 1994 (has links)
Thesis (D. Min.)--Abilene Christian University, 1994. / Includes abstract. Includes bibliographical references (leaves 204-214).
195

Tactite rocks of the Iron Mountain district, Sierra and Socorro Counties, New Mexico Stratigraphy of the easternmost Ventura Basin, California, with a description of a new Lower Miocene mammalian fauna from the Tick Canyon Formation /

Jahns, Richard H. Jahns, Richard H. January 1943 (has links)
Thesis (Ph. D.)--California Institute of Technology, 1943. / No collective t.p.; titles transcribed from individual title pages. Includes bibliographical references.
196

An investigation of Scripps Submarine Canyon its geology, sedimentary regime, and bubbling gases /

Rindell, Anders Koria. January 1991 (has links)
Thesis (M.S.)--San Diego State University, 1991. / Includes bibliographical references (leaves 124-133).
197

Evolução, geometria e preenchimento do complexo de canyons de brejo Grande, bacia de Sergipe-Alagoas

Silva, Braulio Oliveira January 2007 (has links)
Este estudo teve como objetivo principal a definição da origem, evolução, geometria e preenchimento do Complexo de Canyons de Brejo Grande. Este complexo está incluído no intervalo maastrichtiano do Grupo Piaçabuçu, que é composto por uma cunha sedimentar progradante, depositada num sistema plataforma-talude-bacia, do Cretáceo Superior ao Quaternário, na Bacia de Sergipe-Alagoas. Foram utilizados dados sísmicos, perfis de poços, dados bioestratigráficos e descrições de testemunhos e amostras de calha. O complexo é composto de três canyons: Canyon de Brejo Grande, o mais antigo; Canyon do Rio Praúnas e Canyon de Aroeira, o mais novo. A localização e orientação dos canyons foram controladas por falhas da fase rift, reativadas antes da escavação. Foram reconhecidas quatro fases de preenchimento: fase inicial, fase de by-pass, fase dos complexos de canais e fase da cunha progradante. Na fase inicial, foram depositados os complexos de transporte de massa. Eles estão melhor preservados quando preenchem calhas na base do canyon. Na fase de by-pass o canyon atuou como um conduto e apenas depósitos de lags foram preservados. A fase dos complexos de canais ocorreu quando os fluxos gravitacionais não mais transportavam suas cargas para a bacia e depositavam a maior parte de sua carga dentro do canyon. A fase da cunha progradante corresponde à parte do preenchimento depositada no começo da subida do nível relativo do mar. Os complexos de canais são os componentes mais importantes do preenchimento dos canyons. Seus canais são frequentemente isolados espacialmente. Eventos sísmicos anômalos produzidos pelos canais mostram que eles são estreitos, com baixa sinuosidade e continuidade longitudinal variável. Os canais empilham-se verticalmente na parte inferior, mais confinada, do preenchimento dos canyons, e lateralmente na parte superior, menos confinada, dos canyons assimétricos. Os canais migram das partes mais confinadas para as menos confinadas. O método da estratigrafia de seqüências foi usado para estabelecer a evolução do complexo de canyons, definindo as seqüências que os preencheram, as relações de tempo entre aorigem e o preenchimento dos canyons e as superfícies limitantes e internas das seqüências. Foram definidas três seqüências de 3ª ordem. Cada canyon foi preenchido por uma seqüência deposicional composta pelos tratos de sistemas de mar baixo e transgressivo. Nos tratos de mar baixo das seqüências 1,2 e 3 foram identificados o equivalente proximal do leque de fundo de bacia e o complexo de canais do leque de talude. Na seqüência 3, além destes, foi também observada a cunha progradante. O limite inferior da seqüência 1 corresponde à base da biozona de nanofósseis N-280. O limite inferior da seqüência 2 coincide com a base da biozona de nanofósseis N-290. / Canyon The channels stack vertically in the lower, more confined portion of canyons, and laterally in the upper, less confined part of asymmetric canyons. Lateral migration of channels is from the side of steeper to the side of less steep wall, where confinement is smaller. The sequence stratigraphy method was used to establish the evolution of the canyon complex, defining the sequences that filled the canyons and the time relationship between the origin and filling of canyons and the boundary and internal surfaces of sequences. Three third order depositional sequences were defined. Each canyon is filled by a depositional sequence compounded of lowstand and transgressive system tracts. In the lowstand system tracts of the first, second and third sequences were identified a proximal equivalent of the basin floor fan andthe channel complexes of the slope fan. In the third sequence, besides those parts, was also observed the progradational wedge. The inferior limit of the first sequence corresponds to the N- 280 nannofossil biozone base and the inferior limit of the second sequence coincides with the N- 290 nannofossil biozone base.
198

Fish orientation along the longitudinal profile of the Rimov reservoir / Fish orientation along the longitudinal profile of the Rimov reservoir

TUŠER, Michal January 2007 (has links)
The aim of this work was to verify the assumption of random fish orientation in the lacustrine zone of the ``canyon-shaped{\crqq} Rimov reservoir and to compare distributions of fish orientation in the lacustrine and tributary zone. The study confirmed that most fish were oriented randomly in the lacustrine zone of the reservoir, whereas in the tributary fish moved predominantly in parallel with the longitudinal axis of reservoir.
199

Turbulence, Sediment Transport, Erosion, and Sandbar Beach Failure Processes In Grand Canyon

January 2015 (has links)
abstract: This research examines lateral separation zones and sand bar slope stability using two methods: a parallelized turbulence resolving model and full-scale laboratory experiments. Lateral flow separation occurs in rivers where banks exhibit strong curvature, for instance canyon rivers, sharp meanders and river confluences. In the Colorado River, downstream Glen Canyon Dam, lateral separation zones are the principal storage of sandbars. Maximum ramp rates have been imposed to Glen Canyon Dam operation to minimize mass loss of sandbars. Assessment of the effect of restricting maximum ramp rates in bar stability is conducted using multiple laboratory experiments. Results reveal that steep sandbar faces would rapidly erode by mass failure and seepage erosion to stable slopes, regardless of dam discharge ramp rates. Thus, continued erosion of sand bars depends primarily of turbulent flow and waves. A parallelized, three-dimensional, turbulence resolving model is developed to study flow structures in two lateral separation zones located along the Colorado River in Grand Canyon. The model employs a Detached Eddy Simulation (DES) technique where variables larger than the grid scale are fully resolved, while Sub-Grid-Scale (SGS) variables are modeled. The DES-3D model is validated using ADCP flow measurements and skill metric scores show predictive capabilities of simulated flow. The model reproduces the patterns and magnitudes of flow velocity in lateral recirculation zones, including size and position of primary and secondary eddy cells and return current. Turbulence structures with a predominately vertical axis of vorticity are observed in the shear layer, becoming three-dimensional without preferred orientation downstream. The DES-3D model is coupled with a sediment advection-diffusion formulation, wherein advection is provided by the DES velocity field minus particles settling velocity, and diffusion is provided by the SGS. Results show a lateral recirculation zone having a continuous export and import of sediment from and to the main channel following a pattern of high frequency pulsations of positive deposition fluxes. These high frequency pulsations play an important role to prevent an oversupply of sediment within the lateral separation zones. Improved predictive capabilities are achieved with this model when compared with previous two- and three-dimensional quasi steady and steady models. / Dissertation/Thesis / Appendix C Video 3.1 / Appendix C Video 3.2 / Appendix C Video 3.3 / Appendix C Video 3.4 / Appendix C Video 3.5 / Appendix C Video 3.6 / Appendix C Video 3.7 / Appendix F Video 4.1.a / Appendix F Video 4.1.b / Appendix F Video 4.2 / Doctoral Dissertation Geography 2015
200

The Potential for Quagga Mussel Survival in Canyon Lake

January 2018 (has links)
abstract: Quagga mussels are an aquatic invasive species capable of causing economic and ecological damage. Despite the quagga mussels’ ability to rapidly spread, two watersheds, the Salt River system and the Verde River system of Arizona, both had no quagga mussel detections for 8 years. The main factor thought to deter quagga mussels was the stratification of the two watersheds during the summer, resulting in high temperatures in the epilimnion and low dissolved oxygen in the hypolimnion. In 2015, Canyon Lake, a reservoir of the Salt River watershed, tested positive for quagga mussel veligers. In this study, I used Landsat 7 and Landsat 8 satellite data to determine if changes in the surface temperature have caused a change to the reservoir allowing quagga mussel contamination. I used a location in the center of the lake with a root mean squared error (RMSE) of 0.80 and a correlation coefficient (R^2) of 0.82, but I did not detect any significant variations in surface temperatures from recent years. I also measured 21 locations on Canyon Lake to determine if the locations in Canyon Lake were able to harbor quagga mussels. I found that summer stratification caused hypolimnion dissolved oxygen levels to drop well below the quagga mussel threshold of 2mg/L. Surface temperatures, however were not high enough throughout the lake to prevent quagga mussels from inhabiting the epilimnion. It is likely that a lack of substrate in the epilimnion have forced any quagga mussel inhabitants in Canyon Lake to specific locations that were not necessarily near the point of quagga veliger detection sampling. The research suggests that while Canyon Lake may have been difficult for quagga mussels to infest, once they become established in the proper locations, where they can survive through the summer, quagga mussels are likely to become more prevalent. / Dissertation/Thesis / Masters Thesis Civil, Environmental and Sustainable Engineering 2018

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