| Summary: | The finite element method has recently become a well established technique in solving geotechnical problems, and has in the past few years been applied in glaciology to stimulate ice mass flow problems. In fact, the models available have advanced much more rapidly than knowledge of the physical parameters and laws which describe ice needed in the simulation process. In this thesis, several functional flow laws are developed. These laws, it is hoped, will lead to a better flow simulation for ice masses. Parameters such as grain size, age, and fabric, though poorly controlled in the testing of ice, are very important to the flow characteristics of ice as can be shown from a consideration of dislocation movements. A more systematic treatment of these parameters is needed. The influence of initial stresses on flow behaviour not considered in previous finite element method simulations of glacier flow, is shown to be significant. Two finite element schemes are compared, and a scheme based on an implicit approach appears to be somewhat faster in computer time. The importance of temperature to glacier flow is considered in this thesis. It is shown that non-isothermal conditions significantly affect the flow of ice masses. The functional flow laws, and the non-isothermal temperature distribution are used to stimulate flow of the Barnes Ice Cap. The simulation is found to be poor compared to observed results. It is felt that a consideration of initial stresses, better temperature distribution data, and improved flow laws are needed before the finite element method simulation will lead to satisfactory results. Master of Engineering (ME)
|
|---|