BibTex format

author = {Collins, GS},
doi = {10.1002/2014JE004708},
journal = {Journal of Geophysical Research: Planets},
pages = {2600--2619},
title = {Numerical simulations of impact crater formation with dilatancy},
url = {},
volume = {119},
year = {2014}

RIS format (EndNote, RefMan)

AB - Impactinduced fracturing creates porosity that is responsible for many aspects of the geophysical signature of an impact crater. This paper describes a simple model of dilatancy—the creation of porosity in a shearing geological material—and its implementation in the iSALE shock physics code. The model is used to investigate impactinduced dilatancy during simple and complex crater formation on Earth. Simulations of simple crater formation produce porosity distributions consistent with observations. Dilatancy model parameters appropriate for lowquality rock masses give the best agreement with observation; more strongly dilatant behavior would require substantial postimpact porosity reduction. The tendency for rock to dilate less when shearing under high pressure is an important property of the model. Pressure suppresses impactinduced dilatancy: in the shock wave, at depth beneath the crater floor, and in the convergent subcrater flow that forms the central uplift. Consequently, subsurface porosity distribution is a strong function of crater size, which is reflected in the inferred gravity anomaly. The Bouguer gravity anomaly for simulated craters smaller than 25 km is a broad low with a magnitude proportional to the crater radius; larger craters exhibit a central gravity high within a suppressed gravity low. Lower crustal pressures on the Moon relative to Earth imply that impactinduced dilatancy is more effective on the Moon than Earth for the same size impact in an initially nonporous target. This difference may be mitigated by the presence of porosity in the lunar crust.
AU - Collins,GS
DO - 10.1002/2014JE004708
EP - 2619
PY - 2014///
SN - 2169-9097
SP - 2600
TI - Numerical simulations of impact crater formation with dilatancy
T2 - Journal of Geophysical Research: Planets
UR -
UR -
UR -
UR -
VL - 119
ER -