THE DISTRIBUTION OF INTRAPLATE VOLCANISM IN THE PACIFIC OCEAN-BASIN - A SPECTRAL APPROACH

Journal article

Although the major linear island chains in the Pacific Ocean basin have been extensively studied, relatively little attention has been given to the origin of the numerous seamounts and oceanic islands that are concentrated in the W Pacific. Spectral analysis of shipboard gravity and bathymetry data provides a means for statistically estimating the distribution of this volcanism in space and time. Estimates of the power spectrum of the bathymetry PB and the average gravitational admittance Z (cross-spectrum correlation of gravity and bathymetry) were obtained as functions of age of the oceanic lithosphere by dividing the Pacific plate into eight age regions A-H. The power spectrum of the bathymetry is indicative of the overall bathymetric roughness (primarily volcanic) in each region. This roughness shows three gradations: regions A-D(<80Ma) have few volcanic features and are relatively smooth; regions E(80-100Ma) and G(120-140Ma) are of intermediate roughness; and regions F(100-120Ma) and H(>140Ma), with many large volcanic features, are very rough. The average gravitational admittance is indicative of the degree of isostatic compensation of bathymetric features in each region and can be used to estimate the proportion fI of total bathymetric power that was emplaced on relatively old lithosphere and the proportion that formed on young lithosphere at or near a mid-ocean ridge crest. -from Authors

Authors: Ribe, N; Watts, A

• Publication status: Published
• Journal: GEOPHYSICAL JOURNAL OF THE ROYAL ASTRONOMICAL SOCIETY
• Volume: 71
• Issue: 2
• Pages: 333-362
• Publication date: 1982-01-01
• DOI: 10.1111/j.1365-246X.1982.tb05993.x
• EISSN: 1365-246X
• ISSN: 0016-8009
• Language: English