Structural Failure and Drowning of Johnston Atoll, Central Pacific Basin

  1. Barbara H. Keating,
  2. Patricia Fryer,
  3. Rodey Batiza and
  4. George W. Boehlert
  1. Barbara H. Keating

Published Online: 18 MAR 2013

DOI: 10.1029/GM043p0049

Seamounts, Islands, and Atolls

Seamounts, Islands, and Atolls

How to Cite

Keating, B. H. (1987) Structural Failure and Drowning of Johnston Atoll, Central Pacific Basin, in Seamounts, Islands, and Atolls (eds B. H. Keating, P. Fryer, R. Batiza and G. W. Boehlert), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM043p0049

Author Information

  1. Hawaii Institute of Geophysics, University of Hawaii, Honolulu, Hawaii 96822

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 1 JAN 1987

ISBN Information

Print ISBN: 9780875900681

Online ISBN: 9781118664209

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Keywords:

  • Seamounts;
  • Coral reefs and islands

Summary

Emery (1956) and Ashmore (1973) described the geology of Johnston Atoll (Northern Line Islands chain) and pointed out the anomalous structure of the atoll. These studies led Ashmore )1973) to suggest that the atoll itself is tilted. Johnston Atoll appears to be an example of a seamount that is undergoing a transition from an atoll to a drowned seamount (guyot). Submersible studies of the shallow carbonate bank demonstrate that the carbonate bank displays important karstic features. Recent side-scan sonar studies of the southern flank of this seamount provide evidence that the southern flank of the seamount has undergone substantial mass-wasting. We hypothesize that the mass-wasting of the seamount has loaded the seafloor surrounding Johnston Island unevenly. The southeast Johnston Basin lies 700 m shallower than the southwest Johnston Basin. The loading of the southeast Johnston Basin has resulted in differential subsidence of the sea floor surrounding the seamount which has resulted in the tilting of the seamount (0.016°) and is responsible for the drowning of much of the reef. It is suggested that local structural failure, preferential erosion and drainage, and differential subsidence of seamounts can cause drowning of reefs which may lead to the formation of guyots.