Evidence from Gravity Anomalies for Interactions of the Marion and Bouvet Hotspots with the Southwest Indian Ridge: Effects of Transform Offsets

Abstract

The ultra-slow spreading Southwest Indian Ridge (SWIR) presents a unique environment to study the interactions between hotspots and ridges with highly segmented geometry. Using recently available satellite free-air gravity and shipboard bathymetry data, we obtain mantle Bouguer (MBA) and residual mantle Bouguer anomalies (RMBA) by removing from free-air gravity the attractions of seafloor topography, sediment thickness variations, a reference crust, and theoretically-predicted effects of lithospheric cooling. The Bouvet hotspot, previously observed to be associated with anomalous bathymetry and geochemistry near the Bouvet triple junction,. has an MBA axial gravity low of ^100 mGal, implying pronounced localized crustal thickening.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 2001
Accession Number
ADA388896

Entities

People

  • Jennifer E. Georgen

Organizations

  • Woods Hole Oceanographic Institution

Tags

DTIC Thesaurus Topics

  • Amplitude
  • Earth Sciences
  • Engineering
  • Geochemistry
  • Geography
  • Geometry
  • Gravity
  • Gravity Anomalies
  • Long Wavelengths
  • National Security
  • Oceanography
  • Planetary Sciences
  • Ridges
  • Seabed
  • Thickness
  • Three Dimensional
  • Topography

Readers

  • Oceanography.
  • Seismology
  • Space Exploration and Orbital Mechanics.

Technology Areas

  • Space