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Evidence for active hotspots on Venus from analysis of Magellan gravity dataThe 500-Myr average crater retention age for Venus has raised questions about the present-day level of tectonic activity. In this study we examine the relationship between the gravity and topography of four large volcanic swells, Beta, Atla, Bell, and Western Eistla Regiones, for clues about their stage evolution. The Magellan line-of-sight gravity data are inverted using a point mass model of the anomalous mass to solve for the local vertical gravity field. Spectral admittance calculated from both the local gravity inversions and a spherical harmonic model is compared to three models of compensation: local compensation, a 'flexural' model with local and regional compensation of surface and subsurface loads, and a 'hotspot' model of compensation that includes top loading by volcanoes and subsurface loading due to a deep, low density mass anomaly. The coherence is also calculated in each region, but yields an elastic thickness estimate only at Bell Regio. In all models, the long wavelengths are compensated locally. Our results may indicate a relatively old, possibly inactive plume.
Document ID
19950053348
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Smrekar, Suzanne E. (Jet Propulsion Laboratory, California Inst. of Tech., Pasadena, CA United States)
Date Acquired
August 16, 2013
Publication Date
November 1, 1994
Publication Information
Publication: Icarus
Volume: 112
Issue: 1
ISSN: 0019-1035
Subject Category
LUNAR AND PLANETARY EXPLORATION
Distribution Limits
Public
Copyright
Other