The Crustal Structure and Subsidence History of Aseismic Ridges and Mid-Plate Island Chains.

Abstract

This thesis consists of three papers examining problems related to the crustal structure, isostasy and subsidence history of aseismic ridges and mid-plate island chains. Analysis of gravity and bathymetry data across the Ninetyeast and eastern Walvis Ridges indicates these features are locally compensated by an overthickening of the oceanic crust. Maximum crustal thicknesses are 15-30 km. The western Walvis Ridge is also compensated by crustal thickening; however, the isostasy of this part of the ridge is best explained by a plate model of compensation with elastic plate thicknesses of 5-8 km. These results are consistent with the formation of the Ninetyeast and Walvis Ridges near spreading centers on young lithosphere with flexural rigidities at least an order of magnitude less than those typically determined from flexural studies in older parts of the ocean basins.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1978
Accession Number
ADA059651

Entities

People

  • Robert Sherman Detrick Jr

Organizations

  • Woods Hole Oceanographic Institution

Tags

Communities of Interest

  • Energy and Power Technologies
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Atlantic Ocean
  • Computer Programs
  • Coral Reefs
  • Earth Sciences
  • Elastic Properties
  • Equations
  • Geography
  • Glaciology
  • Heat Transmission
  • Long Wavelengths
  • Materials
  • Oceanography
  • Planetary Sciences
  • Power Spectra
  • Ridges
  • Seabed
  • Topography

Fields of Study

  • Geology

Readers

  • Seismology