A giant submarine slope failure on the northern insular slope of Puerto Rico

Schwab, William C.; Danforth, W.W.; Scanlon, Kathryn M.; Masson, Douglas G.

doi:10.1016/0025-3227(91)90149-x

Cited by 31 publications

(18 citation statements)

References 16 publications

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“…The northern edge of the carbonate platform north of Puerto Rico is characterized by two large amphitheater-shaped headwall scarps, the Arecibo amphitheater 37 km north of Arecibo, Puerto Rico [Mercado et al, 2002;Scanlon and Masson, 1996;Schwab et al, 1991] which is 50-km across, and the Loiza amphitheater, 48 km north of Loiza, Puerto Rico [Scanlon and Masson, 1996], which is 35-km across (Figures 2 and 3). Smaller failures are observed adjacent to these amphitheaters, and the westernmost edge of the platform appears to have collapsed but was translated very little.…”

Section: The Northern Edge Of the Carbonate Platformmentioning

confidence: 99%

“…The amphitheater-shaped scar was previously postulated to have formed by a giant submarine slope failure with a displaced volume of over 910-1500 km 3 [Grindlay, 1998;Schwab et al, 1991]. Maximum run-up of 30-55 m was calculated from this failure, with a run-up >10 m along the entire northern coast of Puerto Rico [Mercado et al, 2002].…”

Section: Arecibo Amphitheatermentioning

confidence: 99%

“…A tsunami killed 40 people in NW Puerto Rico following a magnitude 7.3 earthquake in 1918 [Mercado and McCann, 1998]. Large landslide escarpments have been mapped on the seafloor north of Puerto Rico [Grindlay, 1998;Schwab et al, 1991], although their ages are unknown. One of the escarpments, the Arecibo Amphitheater, was simulated as a single failure with run-up on the north shore of Puerto Rico possibly reaching 55 m [Mercado et al, 2002].…”

Section: Introductionmentioning

confidence: 99%

“…Parts of the Puerto Rico trench were previously surveyed with side scan sonar [Grindlay et al, 1997;Scanlon and Masson, 1996;Schwab et al, 1991] and multibeam bathymetry [Dillon et al, 1998] often at lower resolution and with line orientation and spacing that did not provide complete bathymetric coverage. The data, presented here, were collected using the SeaBeam 2112 multibeam sonar system aboard the NOAA ship Ron Brown with sufficient swath overlap and proper line orientation for hydrographic survey.…”

Section: Introductionmentioning

confidence: 99%

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Submarine Slides North of Puerto Rico and Their Tsunami Potential

Brink¹,

Geist²,

Lynett³

et al. 2006

Caribbean Tsunami Hazard

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New multibeam bathymetry of the entire Puerto Rico trench reveals numerous retrograde slope failures at various scales at the edge of the carbonate platform north of Puerto Rico and the Virgin Islands. The slumped material comprises carbonate blocks, which fail, at least in initial stages, as a coherent rock mass. This, combined with the fact that the edge of the carbonate platform is steeper than most continental slopes, indicates a higher potential for run-up than along many other U.S. coasts. The style of slope failure appears to be rock falls, slide blocks and debris avalanches. Secondary failure of the failed carbonate products and of the underlying forearc sediments and rocks may lead to debris flows and turbidity flows. Fissures, discovered in the ocean floor near the edge of the platform, indicate that the process is expected to continue in the future. One of the slope failures, the Arecibo amphitheater, previously thought to represent a single giant slide with a volume of 900-1500 cu. km, appears to comprise smaller failures. The expected maximum tsunami run-up on the northern coast of Puerto Rico from one of these slope failures is <20 m, much lower than previously estimated. A recurrence rate of 100s ky was calculated for the largest observed failures along the edge of the carbonate platform north of Puerto Rico using simple assumptions. Smaller landslides would presumably occur at a higher recurrence rate. Elsewhere around the island, a 20-km wide failure scarp was discovered in the Upper Mona rift and could be associated with the 1918 tsunami and earthquake that hit northwestern Puerto Rico. Large slope failures were also discovered for the first time on the northern side of the Puerto Rico trench. Because Puerto Rico trench slides occur at large water depths (~6000 m), have large horizontal and vertical dimensions, and the directivity from tsunamis emanating from these slides is toward Puerto Rico, they may be of particular concern and may necessitate further study.

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Section: The Northern Edge Of the Carbonate Platformmentioning

confidence: 99%

Section: Arecibo Amphitheatermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Submarine Slides North of Puerto Rico and Their Tsunami Potential

Brink¹,

Geist²,

Lynett³

et al. 2006

Caribbean Tsunami Hazard

View full text Add to dashboard Cite

show abstract

“…An attractive alternative to hurricanes or tsunami initiated by earthquakes is suggested by the work of Grindlay, Hearne, and Mann (2005); Grindlay, Mann, and Dolan (1997);and ten Brink et al (2006), who reported the presence of very large slump features in 3 km of water in the Puerto Rico trench and of cuspate scars on the shelf nearby. They and Schwab et al (1991) compared these slumps to the Storegga slump off Norway, dated 8000 years ago (Jansen et al, 1987), that was the source of a 25-to 30-m-high tsunami that struck Scotland. The ages of the Puerto Rico slumps are so far undetermined, but the reported slump scars involve Pleistocene strata (Grindlay, Hearne, and Mann, 2005).…”

Section: Paleotsunami Vs Cyclonic Stormsmentioning

confidence: 99%