Abstract : Shipboard free air gravity and bathymetric anomalies with an extension of 400 km were identified across the Pitcairn-Easter hotline in the South Pacific. The anomalies are associated with one of the positive geoid undulations observed in the area from satellite data. Several smaller topographic features , volcano-tectonic ridges oriented N65øE, are superimposed on the topographic high. Admittance computations and direct modeling show that the swell topography is compensated by a low density zone within the lithosphere, 4 to 8 km below the crust The volcano tectonic ridges are locally compensated in a classical Airy sense. The swell and the associated ridges were probably created by the action of a thermal anomaly resulting from the interaction of the Easter Island hotspot and of the Easter Microplate accretion centers.
https://hal-insu.archives-ouvertes.fr/insu-01354635
Contributor : Eva Fareau <>
Submitted on : Friday, August 19, 2016 - 10:13:38 AM Last modification on : Friday, September 11, 2020 - 2:56:03 PM Long-term archiving on: : Sunday, November 20, 2016 - 10:08:31 AM
Marcia Maia, G.. Dehghani, M Diament, J Francheteau, P Stoffers. Gravity study of the Pitcairn-Easter hotline. Geophysical Research Letters, American Geophysical Union, 1994, 21, pp.2527-2530. ⟨insu-01354635⟩