Anita Trippet, 1981. "Geologic Processes and Seafloor Stability, Continental Shelf and Slope, Northwest Gulf of Mexico Case Studies", Offshore Geologic Hazards: A Short Course Presented at Rice University, May 2-3, 1981 for the Offshore Technology Conference, Arnold Bouma, Dwight Sangrey, James Coleman, David Prior, Anita Trippet, Wayne Dunlap, James Hooper
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The East and West Flower Garden Banks are located in the High Island Federal lease block area off the coast of southeast Texas-southwestern Louisiana (figure 1). The Flower Garden Banks are the largest of more than 130 submarine banks occurring along the outer continental shelf in the northwestern Gulf of Mexico (Parker and Curray, 1956). What makes the Flower Garden Banks unique is the fact that living reefs have been observed on the crests of both banks, constituting the northernmost thriving tropical shallow water coral reefs on the eastern coast of North America (Bright and Pequegnat, 1974).
Both East and West Flower Garden Banks are perched atop salt-cored diapirs in an area of extensive hydrocarbon accumulation, Exploration and drilling in their immediate vicinity are limited by the boundaries of a national marine sanctuary established around each bank to protect the living reefs.
The bathymetry of the Flower Garden banks area reveals a flat, smooth plain surrounding the two diapirs and sloping gently to about the 150 meter contour, where a sudden increase in steepness marks the edge of the continental shelf (figure 2). The topography of both Flower Garden banks is essentially fault-controlled. East Flower Garden Bank is asymmetrical, with greatest relief along the southeastern flank, where water depth increases from 50 to 130 meters over a distance of one kilometer. West Flower Garden Bank rises from 110 meters water depth to the summit at 24 meters.
Evidence of regional salt movement and active faulting indicates the Flower Garden diapirs
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Offshore Geologic Hazards: A Short Course Presented at Rice University, May 2-3, 1981 for the Offshore Technology Conference
Practically all parts of the United States continental shelves and some segments of the adjacent upper continental slopes are presently subject, or will be in the near future, to exploration and development. The same is true for many continental margins all over the world. Unless the potential influence of hazards is taken into account in the design, installation, and operation of any offshore structure, such structures can pose a threat that could result in pollution, damage, or loss of lives and equipment. This publication, written to accompany an AAPG Short Course, provides some kind of summary of current [at the time of writing] knowledge. Higher categories of geologic hazards as well as individual potentially hazardous geologic phenomena are described and discussed.