Description
Glaciers or ice sheets are natural accumulations of ice possessing in trinsic motion, which have appeared on the Earth’s land surface as a result of the accumulation and transformation of precipitation [2]. Only a very small portion of the surface of the land is now covered by glaciers, and at low latitudes they are found justat high elevations, on mountain slopes. However, glaciers are known to play very important roles in shaping the topography of the Earth, in determiningits past, present, and future climate, and in creating the state of the world Ocean. Recently there has also been a marked increase in the practical value of our knowledge about glaciers, as a part of the human habitat and as a factor affecting the economy. Interest in glaciers on other planets is also growing. Voyages of spacecraft to Jupiter, for instance, have shown that some Jovian satellites possess ice sheets tens of kilometers in thickness. 1: Observations of the Thermal Regime of Glaciers.- 1.1. Measurements of Temperatures Inside Glaciers.- 1.1.1. General Description.- 1.1.2. Temperature Sensors.- 1.1.3. Connecting Lines and Measuring Circuits.- 1.1.4. Measuring Equipment. Increasing the Accuracy. Errors.- 1.1.5. Heating of Temperature Sensors at the Time of Measurement.- 1.2. Sources of Errors During Temperature Measurements in Glacier Boreholes.- 1.2.1. The Temperature Variation Due to the Heat Generated During Drilling. The Stabilization Time..- 1.2.2. The Effect of Free Natural Convection.- 1.2.3. Effects of Other Factors.- 1.2.4. Temperature Measurements at the End (Bottom) of a Borehole.- 2: Thermal Drilling of Glaciers.- 2.1. The Theory of Drilling by Contact with a Heated Solid Surface.- 2.1.1. The Drill Efficiency.- 2.1.2. The Ice Temperature Ahead of a Moving Thermal Drill.- 2.1.3. The Ice Temperature at the Borehole Walls and Bottom.- 2.1.4. The Temperature of the Drill Heating Surface.- 2.1.5. The Thickness of the Water Layer Between the Drill Heater and the Ice.- 2.1.6. Melting or Freezing of the Borehole Side Walls.- 2.2. Methods of Thermal Drilling of Ice.- 2.2.1. Drilling with a High-Speed Jet of Gas or Liquid Without Melting the Ice.- 2.2.2. Drilling with a Gas or Liquid Jet that Melts or Vaporizes the Ice.- 2.2.3. Ice Drilling by Contact with a Heated Solid Surface.- 2.3. Antifreeze Thermal Drilling by Direct Contact with a Solid Heater.- 2.3.1. Drilling Cold Ice with Water Retention in the Borehole.- 2.3.2. Equipment for Antifreeze Thermal Drilling.- 2.3.3. Thermal-Drilling Methods.- 2.3.4. Extracting a ‘Bottom’ Core.- 3: The Theory of the Thermal Regime of Glaciers.- 3.1. The Fundamental Equations and Conditions Describing the State of a Glacier.- 3.2. Equations of Motion of 1).- 4.3.2. Warming Due to Ice Motion (KT
