Glacial crossword

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Across
  1. 2. The breaking away of blocks of ice from an ice sheet or glacier into water.
  2. 3. Where a system changes dramatically between one state and another after the influence of trigger and adjusts to that new state.
  3. 4. The parts of the Earth's crust and atmosphere subject to temperatures below 0°C for at least part of each year. It consists of ice sheets and glaciers, together with sea ice, lake ice, ground ice (permafrost) and snow cover.
  4. 6. A direct change from a solid to a gas without passing through the liquid stage.
  5. 10. A glacier characterised throughout its depth by temperatures close to 0°C.
  6. 15. Ice melts under pressure up-ice side of a small obstacle (stoss) and freezes again on the down-ice side (lee), when the pressure is reduced. This process occurs where obstacles are small enough to enable the latent heat released by lee-side refreezing to be conducted to the stoss side to promote further melting.
  7. 16. When an open system experiences a change in one of the system's variables, a chain of events is triggered, exaggerating the effect of the initial change.
  8. 17. Glacier flow associated with a decrease of velocity in a downglacier direction.
  9. 20. A condition of equilibrium achieved by an open system.
  10. 22. The end of a glacier at any given point in time.
  11. 25. The temperature at which ice melts at a given pressure. The melting point of ice is 0°C near the surface but at deeper levels ice melts at a slightly lower temperature because of the increased pressure (weight) of overlying glacier ice (e.g. beneath 2000 m of ice is -1.6°C).
  12. 26. The collective loss of water from a glacier by processes such as surface melting, evaporation and sublimation.
  13. 28. Glacier flow associated with an increase in velocity in a downglacier direction.
  14. 29. The state of stability in a system.
  15. 30. A glacier that is warm-based in its thicker, central regions as a result of geothermal heating and cold-based at its surface and near its margins where it is frozen to the bed.
Down
  1. 1. Deformations in sediment and bedrock of the Earth's crust as a consequence of glacier loading, dragging, or pushing.
  2. 5. The division between the accumulation zone of a glacier and its ablation zone marking the level at which, over the year, there is no net increase or decrease in the mass of the ice. It is the point at which annual accumulation exactly equals annual melting.
  3. 7. The mechanism by which open systems undergo self- regulation.
  4. 8. The time span from the beginning of the Quaternary to about 11,500 years ago when the most recent continental glacial ended.
  5. 9. A deep fissure in a glacier.
  6. 11. The proportion of the total solar radiation which is reflected by the Earth's surface expressed as a decimal or percentage.
  7. 12. An equilibrium that exists when a system is essentially constant in its relationship between inputs and outputs. There might be variations in flows into and out of the system, such as seasonal, but on average the system is stable.
  8. 13. A system with no transfer of matter across its external boundaries.
  9. 14. The balance between the inputs and outputs of snow and ice in the glacier system.
  10. 18. The collective gain in an ice mass by processes such as snowfall, avalanches and the refreezing of meltwater.
  11. 19. A system in which energy and materials move across its boundaries.
  12. 21. The act of a glacier sliding over the bed due to meltwater under the ice acting as a lubricant.
  13. 23. The change in a system, but in a more gradual way compared to the dramatic change in meta-stable equilibrium.
  14. 24. A term applied to the action of wind.
  15. 25. A glacier characterised by temperatures below freezing point.
  16. 27. The current period of geological time which began 2.6 million years ago.