Premium
Impact cratering in sandstone: The MEMIN pilot study on the effect of pore water
Author(s) -
KENKMANN Thomas,
WÜNNEMANN Kai,
DEUTSCH Alexander,
POELCHAU Michael H.,
SCHÄFER Frank,
THOMA Klaus
Publication year - 2011
Publication title -
meteoritics and planetary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.09
H-Index - 100
eISSN - 1945-5100
pISSN - 1086-9379
DOI - 10.1111/j.1945-5100.2011.01200.x
Subject(s) - impact crater , geology , vaporization , porosity , spall , hypervelocity , pore water pressure , volume (thermodynamics) , characterisation of pore space in soil , mineralogy , geotechnical engineering , materials science , astrobiology , composite material , chemistry , physics , organic chemistry , quantum mechanics , thermodynamics
– Planetary surfaces are subjected to meteorite bombardment and crater formation. Rocks forming these surfaces are often porous and contain fluids. To understand the role of both parameters on impact cratering, we conducted laboratory experiments with dry and wet sandstone blocks impacted by centimeter‐sized steel spheres. We utilized a 40 m two‐stage light‐gas gun to achieve impact velocities of up to 5.4 km s −1 . Cratering efficiency, ejection velocities, and spall volume are enhanced if the pore space of the sandstone is filled with water. In addition, the crater morphologies differ substantially from wet to dry targets, i.e., craters in wet targets are larger, but shallower. We report on the effects of pore water on the excavation flow field and the degree of target damage. We suggest that vaporization of water upon pressure release significantly contributes to the impact process.