The shallow shelf approximation is a better “sliding law” for ice sheet modeling than those sliding laws in which basal velocity is a function of driving stress. The shallow shelf approximation as formulated by Schoof [2006a] is well-suited to this use. Our new thermomechanically coupled sliding scheme is based on a plasticity assumption about the strength of the saturated till underlying the i...

Changes in velocity of the large outlet glaciers and ice streams in Antarctica are important for ice sheet mass balance and hence sea level. The ice flow velocity is also a critical variable in understanding glacier dynamics. Polar Record Glacier, with a calved iceberg in front, is about 50 km to the west of the Zhongshan Station, East Antarctica. SAR interferometry can detect the surface displ...

in this paper, dynamic analysis of the composite truncated sandwich conical shells (stcs) with various boundary conditions subjected to low velocity impact was studied analytically, based on higher order sandwich panel theory. impact was assumed to occur normally over to the top face-sheet and the contact force history is predicted using two solution models of the motion are derived based on ha...

The unusual lobate ejecta deposits of martian impact craters have led to several proposed fluidization mechanisms to explain their morphology. Of the fluidized ejecta craters, double-layered ejecta (DLE) craters, believed to form in a decameters-thick surface ice layer, appear to have anomalously large and highly variable ejecta mobility (EM) ratios. We propose that low-aspect-ratio layered eje...

Ice deformation and basal motion characterize the dynamical behavior of the Greenland ice sheet (GrIS). We evaluate the contribution of basal motion from ice deformation measurements in boreholes drilled to the bed at two sites in the western marginal zone of the GrIS. We find a sustained high amount of basal motion contribution to surface velocity of 44–73% in winter, and up to 90% in summer. ...

Motivated by the need for efficient and accurate simulation of the dynamics of the polar ice sheets, we design high-order finite element discretizations and scalable solvers for the solution of nonlinear incompressible Stokes equations. In particular, we focus on power-law, shear thinning rheologies commonly used in modeling ice dynamics and other geophysical flows. We use nonconforming hexahed...

In this paper, penetration of high velocity impact of 4340 steel and tungsten carbide projectiles with specific shapes in to ceramic armor that includes 10 mm alumina (95%) is considered analytically and simulated with Ls-Dyna software. Bernoulli equation used to consider the penetration velocity in ceramics, shows that the penetration is better and easier by increasing projectile density. The ...