Subsurface Structure of Oblique Impact Craters II

Impacts of asteroids on planetary surfaces usually occur obliquely with an average impact angle of 45°. The impact vector can be analysed by the uneven distribution of ejecta. On Earth ejecta blankets of meteorite craters are very rare and incompletely preserved, but different degrees of erosion often allow to study the crater floor in detail. The working hypothesis of this proposal is that the crater floor flow field is capable to provide direct evidence for oblique impacts via momentum transfer from projectile to the target. The objective is to determine the impact vector of terrestrial craters from the subsurface crater structure and to infer the structural inventory of oblique impacts. For this purpose we investigate several impact craters (Wolfe Creek, WA, Australia; Meteor Crater, AZ, USA; Matt Wilson, NT, Australia; Spider, WA, Australia) which are believed to have been formed by oblique impacts. In a thorough structural analysis deviations from a radial symmetry of the crater floor structure including a study on shock and damaging in different sectors of the crater will be deduced. A kinematic analysis will be performed to quantify dominant flow trajectories which are relevant for reconstruction of the projectile´s vector. The analysis will be linked to 3D numerical modeling of the crater floor flow in an oblique impact scenario.

Principal Investigators
Kenkmann, Thomas-Bernd Dr. (Details) (Mineralogy)

Duration of Project
Start date: 06/2008
End date: 05/2009

Last updated on 2020-09-03 at 17:13