The purpose and scope of this book on theoretical glaciology is outlined in the Introduction. Its aim is to study the theoretical aspects of'ice mechanics' and the 'dynamics of ice masses in a geophysical environment. For the mature reader, the book can serve as an introduction to glaciology. How ever, this is not what I would regard as advisible. Glaciology is an inter disciplinary science in which many special scientific disciplines play their part, from descriptive geography to fairly abstract mathematics. Advance ment will evolve from a merger of two or more branches of scientific specialization. In the last 20 years, several researchers in different fields of glaciology have written books emphasizing the aspects of their specialities and I have listed some which are known to me at the end of the Introduction. When glancing through these books, one recognizes that the mathematical aspects of glaciology are generally glossed over and, to date, there seems to be nothing available which concentrates on these. Therefore, I have written this book in an effort to close the gap and no apologies are offered for the mathematical emphasis. Rather, I believe that this neglect has, to a certain extent, aggra vated progress in the modelling of glaciology problems."

The purpose and scope of this book on theoretical glaciology is outlined in the Introduction. Its aim is to study the theoretical aspects of'ice mechanics' and the 'dynamics of ice masses in a geophysical environment. For the mature reader, the book can serve as an introduction to glaciology. How ever, this is not what I would regard as advisible. Glaciology is an inter disciplinary science in which many special scientific disciplines play their part, from descriptive geography to fairly abstract mathematics. Advance ment will evolve from a merger of two or more branches of scientific specialization. In the last 20 years, several researchers in different fields of glaciology have written books emphasizing the aspects of their specialities and I have listed some which are known to me at the end of the Introduction. When glancing through these books, one recognizes that the mathematical aspects of glaciology are generally glossed over and, to date, there seems to be nothing available which concentrates on these. Therefore, I have written this book in an effort to close the gap and no apologies are offered for the mathematical emphasis. Rather, I believe that this neglect has, to a certain extent, aggra vated progress in the modelling of glaciology problems."

Modern continuum mechanics is the topic of this book. After its introduction it will be applied to a few typical systems arising in the environmental sciences and in geophysics. In large lake/ocean dynamics peculiar effects of the rotation of the Earth will be analyzed in linear/nonlinear processes of a homogenous and inhomogenous water body. Strong thermomechanical coupling paired with nonlinear rheology affects the flow of large ice sheets (such as Antarctica and Greenland) and ice shelves. Its response to the climatic forcing in an environmental of greenhouse warming may significantly affect the life of future generations. The mechanical behavior of granular materials under quasistatic loadings requires non-classical mixture concepts and encounters generally complicated elastic-plastic-type constitutive behavior. Creeping flow of soils, consolidation processes and ground water flow are described by such theories. Rapid shearing flow of granular materials lead to constitutive relations for the stresses which incorporate rate independent behavior of Mohr-Coulomb type together with dispersive stress contributions due to particle collisions. Rockfalls, sturzstroms, snow and ice avalanches, but also debris flow and sea ice drifting can be described with such formulations.

Wind erosion has such a pervasive influence on environmental and agricultural matters that academic interest in it has been continuous for several decades. However, there has been a tendency for the resulting publications to be scattered widely in the scientific litera ture and consequently to provide a less coherent resource than might otherwise be hoped for. In particular, cross-reference between the literature on desert and coastal morphology, on the deterioration of wind affected soils, and on the process mechanics of the grain/air flow system has been disappointing. A successful workshop on "The Physics of Blown Sand," held in Aarhus in 1985, took a decisive step in collecting a research community with interests spanning geomorphology and grain/wind process mechanics. The identification of that Community was reinforced by the Binghampton Symposium on Aeolian Geomorphology in 1986 and has been fruitful in the development of a number of international collaborations. The objectives of the pre sent workshop, which was supported by a grant from the NATO Scientific Affairs Division, were to take stock of the progress in the five years to 1990 and to extend the scope of the community to include soil deterioration (and dust release) and those beach processes which link with aeolian activity on the coast."

Beim Entwurf und bei der Bemessung eines allgemeinen Tragwerks wird man vor allem die Spannungsverteilung (das Spannungsfeld) zu bestimmen suchen. Gelegentlich wird es auch notwendig sein, in bestimmten Punkten des Tragwerks die Verschiebun- gen zu berechnen, um abzuschatzen, ob vorgegebene Hoechstwerte nicht uberschritten werden. In manchen Fallen, besonders wenn Belastung und Tragwerkverhalten zeitab- hangig sind, muss auch der gesamte Verschiebungszustand, also das Verschiebungsfeld, bekannt sein. ine berechnete Spannungsverteilung sollte der Bedingung des Gleichge- wichts zwischen inneren und ausseren Kraften genugen. Gleichzeitig sollten die Ver- schiebungen stetig sein (Vertraglichkeitsbedingung). Um fur eine gegebene Bemessungsaufgabe ein System von Spannungen und Ver- formungen zu erhalten, mussen zunachst die Grundgleichungen des Problems aufge- stellt werden, die den Gleichgewichts- und Vertraglichkeitsbedingungen in gewisser Weise genugen. Ganz abgesehen von der Loesbarkeit der fraglichen Gleichungen wird es in der Regel schwierig sein, die Gleichungen den besonderen Gegebenheiten der Geo- metrie, Belastung und Materialeigenschaften anzupassen. Der entwerfende Ingenieur wird daher gewisse Ungenauigkeiten in Kauf nehmen mussen, bevor er uberhaupt mit der Prozedur der Aufloesung der Gleichungen beginnt. Zur Beschreibung von zwei- oder dreidimensionalen Spannungs- und Verschiebungszu- standen werden partielle Differentialgleichungen erhalten, fur welche exakte Loesungen nur in Sonderfallen gefunden werden. Auch wird es nur in wenigen Fallen moeglich sein, brauchbare Annaherungen mit wenigen Gliedern eines Reihenansatzes zu finden.