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Full-Text Articles in Physical Sciences and Mathematics
The Effect Of Viscosity On Impact Cratering And Possible Application To The Icy Satellites Of Saturn And Jupiter, Jonathan H. Fink, Donald Gault, Ronald Greeley
The Effect Of Viscosity On Impact Cratering And Possible Application To The Icy Satellites Of Saturn And Jupiter, Jonathan H. Fink, Donald Gault, Ronald Greeley
Geology Faculty Publications and Presentations
Impact experiments in Newtonian fluids with a range of viscosities of 10-3 to 60 Pa s demonstrate that transient prater volume and shape (depth-to-diameter: ratio) depend on target viscosity as well as on gravity. Volume is reduced, and depth-to-diameter ratio is increased for cratering events in which viscosity plays a dominant role. In addition to being affected by target kinematic viscosity, viscous scaling is most strongly influenced by projectile diameter, less strongly by projectile velocity, and least strongly by gravity. In a Planetary context, viscols effects can occur for craters formed by small or slow moving impacting bodies, low …
Igneous Dikes At Long Valley, Ca: Emplacement Mechanisms And Associated Geologic Structures, David D. Pollard, Jonathan H. Fink, Paul T. Delaney
Igneous Dikes At Long Valley, Ca: Emplacement Mechanisms And Associated Geologic Structures, David D. Pollard, Jonathan H. Fink, Paul T. Delaney
Geology Faculty Publications and Presentations
Two hypotheses for dike emplacement are: (1) magma flows into and dilates pre-existing fractures; or (2) magma flows into and dilates self-generated fractures. In the first case dikes should be parallel to an element of the rock fabric; in the second, they should be perpendicular to the least compressive stress. The two hypotheses suggest different dike intrusion and fissure eruption mechanisms and therefore different strategies for monitoring igneous events at Long Valley. We derive a method to distinguish the two mechanisms, a priori, from in-situ stress measurements and estimates of magma pressure. Estimates of relative dilation and slip across a …