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Tectonics of planetary surfaces
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Processes in the interior of planetary bodies cause the formation of tectonic
structures like orogenic belts and graben. The structures we see today reflect
the physical properties of the lithosphere at the time of their formation and their
analysis gives us clues to the evolution of the planetary lithosphere.
Examples for surface deformations caused by tectonic processes
may be found in the whole solar system: The surfaces of the Moon and Mercury are
abundant in compressive structures, Mars and Venus show additional extensional
features and the surfaces of the icy moons in the outer solar system are also
covered by them. However, the processes responsible for the deformations may
vary considerably. The simulations therefore always have to take into account
the peculiarities of the bodies considered.
The data
Tectonic structures may be identified using image data, which is
available for many moons and planets in high quality. The physical modeling
additionally requires topographic information, which can be extracted from
the images using, e.g. stereographic reconstruction.
Global digital elevation models, which
have been produced using specialized instruments on board satellite missions, have
been obtained for the Earth, Venus, the Moon and Mars. A topographic
model of Mercury will be compiled from the data that will be collected by the
NASA Messenger Mission, which was launched in 2004.
Numerical simulations
We simulate the formation of tectonic structures using one and two dimensional
structural mechanics models, applying half-analytical and finite element
techniques. The models are then compared to the actual topography to
determine the elastic properties of the lithosphere. It is thus possible to
look beneath the surface and into the past of the planetary body considered
and gain information about the physical properties of its lithosphere.
Since the latter are strongly temperature depended, the collected data allows
us to gain insight into the thermal evolution of the planet.
Contact:
Dr. Matthias Grott
Publikationen
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The eastern Coracis Fossae rift system in the Thaumasia Region, Mars.
HRSC images have been combined with a digital elevation model (RV: Rift valley,
F: Rift flank, V: Volcano, RP: Ridged Plain).
Figure by E. Hauber, DLR.
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Schematic diagram of graben formation in an extended lithosphere
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Finite element simulation of the flexure of a 20 km thick lithospheric plate after
an extension of 4 km has been applied. Red: Extensional stress, blue: Compressional
stress.
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Address
Institute of Planetary Research
Department of Planetary Physics
Rutherfordstr. 2
D-12489 Berlin
Internet: 
http://www.dlr.de/pf
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Head of Department
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Prof. Dr. Doris Breuer
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