Preimpact porosity controls the gravity signature of lunar craters
File(s)
Author(s)
Type
Journal Article
Abstract
We model the formation of lunar complex craters and investigate the effect of preimpact porosity on their gravity signatures. We find that while preimpact target porosities less than ~7% produce negative residual Bouguer anomalies (BAs), porosities greater than ~7% produce positive anomalies whose magnitude is greater for impacted surfaces with higher initial porosity. Negative anomalies result from pore space creation due to fracturing and dilatant bulking, and positive anomalies result from destruction of pore space due to shock wave compression. The central BA of craters larger than ~215 km in diameter, however, are invariably positive because of an underlying central mantle uplift. We conclude that the striking differences between the gravity signatures of craters on the Earth and Moon are the result of the higher average porosity and variable porosity of the lunar crust.
Date Issued
2015-11-18
Date Acceptance
2015-11-01
Citation
Geophysical Research Letters, 2015, 42 (22), pp.9711-9716
ISSN
1944-8007
Publisher
American Geophysical Union (AGU)
Start Page
9711
End Page
9716
Journal / Book Title
Geophysical Research Letters
Volume
42
Issue
22
Copyright Statement
©2015. American Geophysical Union.
All Rights Reserved.
All Rights Reserved.
Sponsor
Science and Technology Facilities Council (STFC)
Grant Number
ST/J001260/1
Subjects
Science & Technology
Physical Sciences
Geosciences, Multidisciplinary
Geology
IMPACT CRATERS
CONTINENTAL-CRUST
MASCON BASINS
SIMULATIONS
GRAIL
MOON
VELOCITIES
ORIGIN
Publication Status
Published