Harvard Department of Astronomy<br>
Special Seminar<br>
<br>
TUESDAY, MARCH 28<br>
2:00 pm, Phillips Auditorium, 60 Garden St.<br>
<br>
Magma Oceans, Early Atmospheres, and Mantle Evolution in Young Terrestrial Planets<br>
<br>
Dr. Linda T. Elkins-Tanton<br>
Brown University<br>
<br>
Abstract: Significant and perhaps complete melting of the young<br>
terrestrial planets is expected from radiogenic heating, heat of<br>
accretion, and the potential energy release of core formation. The<br>
rate of subsequent magma ocean solidification is tempered by volatiles<br>
that are degassed to the atmosphere, where they decrease atmospheric<br>
transmission, reduce heat flux from the planets surface, and slow<br>
solidification. I will present results from a new model that<br>
integrates silicate mantle solidification with atmospheric formation,<br>
linking heat flux, convective velocity, and cooling rates with<br>
resulting mantle and atmospheric compositions. Magma ocean processes<br>
may be responsible for initial atmospheric mass and composition,<br>
initial mantle heterogeneity and compositional stability, and<br>
formation of both an early crust and planetary magnetic field.<br clear="all"><br>