Chapter 2: This chapter introduces the five study sites (Ras Al‐Qasabah; Al Wajh; Yanbu; Farasan Banks; and Western Farasan Islands) along with the fieldwork and detailed benthic mapping and bathymetry mapping conducted in the Saudi Arabian Red Sea. In the Western Farasan Islands two candidate mapping technologies were compared. Firstly, the QuickBird multispectral satellite sensor and secondly the CASI‐550 airborne hyperspectral sensor. In processing the CASI imagery, it was necessary to customize processing to correct for an unusual across‐track artifact caused by lens condensation. On the basis of cost, logistical constraints, spectral reliability, and project needs, multispectral imagery was found to be the most appropriate technology for regional‐scale mapping. Over 20,000 sq. km of high quality QuickBird imagery were amassed across the five study sites. This represents approximately half the shallow water ( Chapter 3: Coral reefs and their associated accumulations of carbonate sediment adopt particularly complex planform geometries atop the coastal shelf of the Saudi Arabian Red Sea. By assembling 95,000 sq. km of remote sensing data into a GIS, this study aims to relate the morphology of these shallow‐water depositional environments to processes that sculpt the coastal zone. A typology is developed that sorts carbonate systems into end‐members on the basis of their morphology and relationship to the coastline. The resulting GIS was interrogated for spatial patterns in the distribution and abundance of the end‐members. While several depositional morphologies are present throughout the length of the Saudi Arabian Red Sea, the occurrence of others is restricted to narrow regions of latitude. Such differences in distribution can be explained in process‐terms by the rift tectonics of the Red Sea basin, spatial variability in the presence of sub‐seafloor evaporites, and the input of siliciclastic detritus onto the coastal shelf via wadis. This chapter provides a foundation for understanding the morphological diversity of shallow‐water carbonate systems in both the modern ocean and rock record. Chapter 4: In this chapter a framework is proposed for spatially estimating a proxy for coral reef resilience using remote sensing. Data spanning over 20,000 sq. km of coral reef habitat were obtained using the commercial QuickBird satellite, and freely available imagery (NASA, Google Earth). Principles of coral reef ecology, field observation, and remote observations, were combined to devise mapped indices. These indices capture important and accessible components of coral reef resilience. Indices are divided between factors known to stress corals, and factors incorporating properties of the reef landscape that resist stress or promote coral growth. The first‐basis for a remote sensed resilience index (RSRI), an estimate of expected reef resilience, is proposed. Developed for the Red Sea, the framework of the analysis is flexible and with minimal adaptation, could be extended to other reef regions. The chapter illustrates how remote sensing can be used to deliver more than simply habitat maps of coral reefs. Chapter 5: In this chapter, a fundamental measure of coral reef health, coral cover, is assessed in relation to two physical parameters, water depth and wave height. Light availability declines rapidly with depth, which influences the photosynthetic productivity of coral. Where waves break, they produce a severe increase in marine turbulence, and generate currents that may extend beyond the surf zone. The study is focused on the Farasan Banks where some 4000 sq. km of reef habitat are spread across 12,000 sq. km of the Saudi Arabian coastal shelf. The size of the system creates logistical challenge for standard field‐based monitoring methodologies, such as SCUBA surveys. Here, rapid video assessments were employed to deliver measures of coral health across eight percentage cover classes at 472 locations. Whilst water depth can be reliably derived from satellite, assessing wave height is problematic since the parameter is both spatially and temporally variable. Using daily, satellite derived meteorology, a spatially explicit wave model was developed spanning the nine year period from 1999 to 2008. For the majority of the video sites in the Farasan Banks, coral cover was found to be Chapter 6: Carbonate sequence stratigraphy is founded on the principle that changes in relative sea level are recorded in the rock record by the accumulation of sediment with relative‐water‐depth dependent attributes. While at the scale of a shelf‐to‐basin transect, facies clearly stratify by water depth, the relationship blurs for depths
| Date of Award | Aug 8 2013 |
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| Original language | English |
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| Supervisor | Samuel J. Purkis (Supervisor), Anew W. Bruckner (Advisor), Richard E. Dodge (Advisor), James A. Goodman (Advisor) & Bernhard Riegl (Advisor) |
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