The determination of the kinematics and dynamics of ice motion

Analytical solutions are obtained for equations from which differential kinematic parameters (DKP) of ice motion are determined. The solutions show that methods previously used to calculate the DKP (vorticity, divergence, and normal and shear deformation rates) were not correct. Also, the analysis shows that the time interval t between position fixes must be within specific limits. For time intervals greater than t, the equations used to calculate the DKP become non-linear. This method can provide an inexpensive means of determining ice kinematics on a realtime basis. An example is given of time histories of the DKP in which all of the DKP had relatively large variations and a change in sign. These types of changes could be used to alert personnel to changes in the ice field. Ice dynamics, including the influence of water stress, may be studied using the DKP.