Northern Guam geospatial information server
Cliffs in northern Guam
Cliffs are significant vertical or near vertical exposures of bedrock. In Guam, they are composed of limestone. Much of the perimeter of northern Guam is delineated by sheer cliffline that abuts the ocean or a narrow coastal terrace. In general, cliffs are products of erosion (which can leave behind walls of relatively resistant rock) or form as escarpments (where rock bodies undergo vertical displacement along geologic faults). In Guam, however, the vast majority of cliffs started as coral reefs. They originally formed underwater and became walls of limestone when they were tectonically elevated above sea level. The height of cliffs around the northern Guam plateau is variable. This is because the plateau has not been elevated evenly and is tilted north-to-south. The cliffs’ extent above the sea level reaches 160-180 m in the north at Ritidian and Pati points, 70 m at the popular tourist lookout at Amantes Point, and 30 m farther south in Tamuning.
Text above is slightly modified from "Environments of Guam" by Danko Taborosi, David R. Burdick, Claudine M. Camacho, Frank Camacho, published by BessPress, 2013.
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