『Abstract
　This article discusses the terminological and disciplinary problems associated with the point of view that ice is a rock, resulting from a dynamic development of earth sciences which have begun the research into other planets as well. Such a position necessitates a revision of the definitions of the hydrosphere, atmosphere and lithosphere. It is the state that determines which particular sphere ice belongs to. Water is understood to be a triphase substance. As a result permafrost should now include the “cold” layer of polythermal glaciers. Rock glaciers are features that integrate glacial and periglacial permafrost. This facilitates the research into the interaction between the glacial and the periglacial environment by recognizing the leading role of the isotherm 0℃ as the physical feature integrating these fields.

Keywords: ice; glacier; permafrost; terminology』

1. Introduction
2. What is ice?
　2.1. Rheological properties
3. History of ice study
4. The Earth's spheres
　4.1. The hydrosphere
　4.2. The atmosphere
　4.3. The lithosphere
　　4.3.1. Ice
　　4.3.2. Snow
　　4.3.3. Glaciers
　　4.3.4. Permafrost
　4.4. Temperature and permafrost relationshio in lithosphere
　4.5. Glacial permafrost
　4.6. Rock glaciers
5. Earth sciences and planetary sciences
　5.1. Planetary science
　5.2. Geomorphology and geology of glaciers
6. Conclusions and outlook
Acknowledgements
References