The effects of Venus' thermal structure on buoyant magma ascent

The recent Magellan images have revealed a broad spatial distribution of surface volcanism on Venus. Previous work in modeling the ascent of magma on both Venus and Earth has indicated that the planetary thermal structure significantly influences the magmatic cooling rates and thus the amount of magma that can be transported to the surface before solidification. In order to understand which aspects of the thermal structure have the greatest influence on the cooling of ascending magma, we have constructed magma cooling curves for both plutonic and crack buoyant ascent mechanisms, and evaluated the curves for variations in the planetary mantle temperature, thermal gradient curvature with depth, surface temperature gradient, and surface temperature. The planetary thermal structure is modeled as T/T(sub 0) = 1-tau(1-Z/Z(sub 0)(exp n), where T is the temperature, T(sub 0) is the source depth temperature, tau = 1-(T(sub s)/T(sub 0)) where T(sub s) is the planetary surface temperature, Z is the depth, Z(sub 0) is the source depth, and n is a constant that controls thermal gradient curvature with depth. The equation is used both for mathematical convenience and flexibility, as well as its fit to the thermal gradients predicted by the cooling half-space models. We assume a constant velocity buoyant ascent, body-averaged magma temperatures and properties, an initially crystal-free magma, and the same liquidus and solidus for both Venus and Earth

1952 yield trials with corn hybrids in Missouri

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1970 virus ratings for corn strains in Missouri

Cover title."This Special Report is a contribution from the Departments of Agronomy and Entomology, University of Missouri Agricultural Experiment Station, projects 3770 and 145; and Crops Research Division, Agricultural Research Service, U.S. Department of Agriculture"--Page 2 of cover

Virus ratings of corn strains in Missouri, 1969

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Virus ratings of corn strains in Missouri, 1968

Cover title."Joint contribution of the Departments of Agronomy and Entomology of the Agricultural Experiment Station, University of Missouri and the Crops Research results reported here are from Missouri Experiment Station Project 579"--P. [2]

Date of planting studies with corn in the Missouri Delta area

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1951 yield trials with corn hybrids in Missouri

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Hybrid seed corn production in Missouri

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Date-of-planting studies with corn : North Missouri Research Center

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