Thermal History of Planetary Objects and Exoplanets - Tilmann Spohn (SET...
Mετάδοση με ζωντανή ροή στις 16 Αυγ 2013
SETI Talks archive: http://seti.org/talks
Speaker: Tilman Spohn, Director of the Institute for Planetary Research at DLR, Berlin
Abstract:
Convection
in the interiors of planetesimals (asteroids), planets, and satellites
is driving the thermal and chemical evolution of these bodies including
the generation of possible magnetic fields. The wide size range induces
a wide range of time scales from hundreds of thousands of years for
small planetesimals to a few tens of Gigayears for massive super-Earths.
Dr
Spohn will present a model that includes mantle convection, mantle
water vapor degassing at mid-oceanic ridges and regassing through
subduction zones, continental crust formation and erosion and water
storage and transport in a porous oceanic crust that includes hydrous
mineral phases.
Dr. Spohn will show how an abiotic world is
predicted to have a much drier mantle than the present Earth but may
have a similar surface coverage by continents. The reduced rate of
continental crust production on the abiotic world would be balanced by a
reduced rate of continent erosion. He will suggest that through the
effect of water on the mantle rheology, the biotic world would tend to
be tectonically more active and have a more rapid long-term
carbon-silicate cycle.
Speaker: Tilman Spohn, Director of the Institute for Planetary Research at DLR, Berlin
Abstract:
Convection
in the interiors of planetesimals (asteroids), planets, and satellites
is driving the thermal and chemical evolution of these bodies including
the generation of possible magnetic fields. The wide size range induces
a wide range of time scales from hundreds of thousands of years for
small planetesimals to a few tens of Gigayears for massive super-Earths.
Dr
Spohn will present a model that includes mantle convection, mantle
water vapor degassing at mid-oceanic ridges and regassing through
subduction zones, continental crust formation and erosion and water
storage and transport in a porous oceanic crust that includes hydrous
mineral phases.
Dr. Spohn will show how an abiotic world is
predicted to have a much drier mantle than the present Earth but may
have a similar surface coverage by continents. The reduced rate of
continental crust production on the abiotic world would be balanced by a
reduced rate of continent erosion. He will suggest that through the
effect of water on the mantle rheology, the biotic world would tend to
be tectonically more active and have a more rapid long-term
carbon-silicate cycle.
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