Effect of target properties and impact velocity on ejection dynamics and ejecta deposition
File(s)Artikel-QuarzejektaIV_revIII_rev2II_rein.pdf (2.13 MB)
Accepted version
Author(s)
Luther, Robert
Zhu, Meng-Hua
Collins, GS
Wunnemann, Kai
Type
Journal Article
Abstract
Impact craters are formed by the displacement and ejection of target material. Ejection angles and speeds during the excavation process depend on specific target properties. In order to quantify the influence of the constitutive properties of the target and impact velocity on ejection trajectories, we present the results of a systematic numerical parameter study. We have carried out a suite of numerical simulations of impact scenarios with different coefficients of friction (0.0–1.0), porosities (0–42%), and cohesions (0–150 MPa). Furthermore, simulations with varying pairs of impact velocity (1–20 km s−1) and projectile mass yielding craters of approximately equal volume are examined. We record ejection speed, ejection angle, and the mass of ejected material to determine parameters in scaling relationships, and to calculate the thickness of deposited ejecta by assuming analytical parabolic trajectories under Earth gravity. For the resulting deposits, we parameterize the thickness as a function of radial distance by a power law. We find that strength—that is, the coefficient of friction and target cohesion—has the strongest effect on the distribution of ejecta. In contrast, ejecta thickness as a function of distance is very similar for different target porosities and for varying impact velocities larger than ~6 km s−1. We compare the derived ejecta deposits with observations from natural craters and experiments.
Date Issued
2018-08-01
Date Acceptance
2018-06-07
Citation
Meteoritics and Planetary Science, 2018, 53 (8), pp.1705-1732
ISSN
1086-9379
Publisher
Wiley
Start Page
1705
End Page
1732
Journal / Book Title
Meteoritics and Planetary Science
Volume
53
Issue
8
Copyright Statement
© The Meteoritical Society, 2018. This is the accepted version of the following article, which has been published in final form at https://onlinelibrary.wiley.com/doi/abs/10.1111/maps.13143.
Sponsor
Science and Technology Facilities Council (STFC)
Grant Number
ST/N000803/1
Subjects
Science & Technology
Physical Sciences
Geochemistry & Geophysics
OBLIQUE IMPACTS
QUARTZ SAND
PROJECTILE DENSITY
SHOCK METAMORPHISM
CRATER FORMATION
FLOW-FIELD
SIMULATION
MODEL
FRAGMENTATION
DISTRIBUTIONS
0201 Astronomical and Space Sciences
0402 Geochemistry
0403 Geology
Geochemistry & Geophysics
Publication Status
Published
Date Publish Online
2018-07-18