Volcanism on Venus as inferred from the morphometry of large shields.
Abstract
The surface of Venus possesses a wide variety of volcanic styles and landforms that provide clues both to the physical and chemical properties of the magma and to the nature of the crust and lithosphere. Prior to acquisition of Magellan data, broad and low domes interpreted as shields have been found to be the most convenient volcanic edifices on Venus for morphometric study using radar data from Earth-based observatories and from Pioneer Venus and Venera 15/16 spacecraft. The gross shapes and estimated volumes of 12 such features larger than 250 km in basal diameter between latitudes 20° and 90°N are described and compared with volcanos on Mars and the Hawaiian Big Island shield complex. The measured heights of the shields are used in conjunction with a reasonable range of magma and rock densities to estimate the depths to deep magma sources, giving an average depth to melting of 25 km beneath the venusian plains with a range in depth of 3 to 40 km. These values coincide with independent estimates of the average crustal thickness on Venus.
- Publication:
-
Lunar and Planetary Science Conference Proceedings
- Pub Date:
- 1991
- Bibcode:
- 1991LPSC...21....3S
- Keywords:
-
- Bedrock;
- Planetary Craters;
- Venus Surface;
- Volcanology;
- Chemical Properties;
- Physical Properties;
- Planetary Crusts;
- Lunar and Planetary Exploration