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Impact
cratering is a fundamental geologic process throughout the solar system.
Understanding this process requires multi- and interdisciplinary research that
includes studies of natural craters, laboratory experiments, and numerical
simulations. In this general context a Multidisciplinary
Experimental and Modeling
Impact Research Network
(MEMIN
Forschergruppe)
was established as a DFG financed Research Unit (Forschergruppe) comprising
geoscientists, physicists, and engineers. Central to MEMIN is a newly designed
two-stage light gas gun capable to produce craters in the decimeter-range in
solid rocks, a size previously not achieved at the laboratory scale that
enables detailed spatial analyses. The proposed cratering experiments on
sandstone targets comprise a parametric study of the role of water, porosity,
target layering, and impact velocity on cratering mechanics, shock effects,
and projectile distribution during cratering. The work program includes (I)
complete mineralogical-petrophysical, and mechanical characterization of the
target prior to and after the experiment using, for example, state-of-the-art
geophysical tools for meso-scale tomography and microstructural analyses at
the nano-scale, (II) stringent control of the impact experiment itself with
newly developed in-situ real-time measurements of fracture propagation,
stresses, crater growth and ejecta dynamics, and (III) numerical modeling of
the complete process. MEMIN is designed to yield a solid data base for
validation and refining of numerical cratering models that will allow scaling
of meso-scale observations to the size of natural craters. MEMIN will further
our understanding of impact damaging of rocks and, hence, the nature of
geophysical signatures of terrestrial craters.
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