Glaciers and ice sheets

Reeh, N. (1989). Dating by ice flow modeling a useful tool or an exercise in applied mathematics In "The Environmental Record in Glaciers and Ice Sheets" (H. Oeschger and C. C. Langway, eds), pp. 141-159. Wiley, New York. 

The Planetary Energy Balance [3] of Incoming Solar (340 W/m2) minus Reflected (101 W/m2) minus Radiated (238 W/m2) = 1 W/m2. This excess energy warms the oceans and melts glaciers and ice sheets. The GHG component is 2 W/m2. The amount of heat required to melt enough ice to raise sea level 1 m is about 12 Watt-years (averaged over the planet)—energy that could be accumulated in 12 years if the planet is out of balance by 1 W/m2 per year. 

Seasonally, the melting of small glaciers and ice sheets on land provides fresh water for streams, rivers, and lakes. Over the winter, falling snow and precipitation build up in snowpacks in the mountains. When warm weather arrives in spring, both the snow and ice melt and feed local water systems. According to the U.S. Geological Survey, as much as 75 percent of the freshwater supply in the... 

Throughout Earth s history, the size of glaciers and ice sheets and the amount of melting has varied, but it has always been a key part of the water cycle. Today, scientists are concerned that our glaciers and ice sheets are melting fast—perhaps too fast. 

Storage of water in glaciers and ice sheets is important because of sheer size. While glaciers, ice sheets, and ice caps do not hold the majority of Earths water, they do hold the majority of the planets fresh water (nearly 70 percent).6 Without the simple phase change known as melting, we would not have access to these enormous reserves of fresh water. 

Freezing, the opposite of melting, is the process by which a liquid changes into a solid. It is the phase change responsible for creating frozen forms of precipitation. Glaciers and ice sheets are formed as the result of the freezing process. 

A snowflake is made up of ice crystals that are stuck together. Snowflakes form high in Earths atmosphere. Hail is a frozen mass of water that often forms inside thunderstorms. Sleet is made up of drops of rain that freeze as they fall to Earths surface. Freezing rain is precipitation that falls as liquid but freezes when it hits the cold ground. Together, these different forms of frozen precipitation move drops of liquid water out of the atmosphere and onto Earths surface where they can melt and seep into oceans and groundwater or freeze and build up to create glaciers and ice sheets. 

A full-scale complex study of the dynamics of the AHLCB system has not been started as yet. On the whole, there are isolated studies with details of partial processes taking place in this system. But, these studies by and large disregard glaciers and ice sheets which cover about 10% of the Earth s land area. Glaciers are masses of ice that accumulate from snowfall over long time periods and descend from higher to lower... 

McElroy M. B. (1989) Smdies of polar ice insights for atmospheric chemistry. In The Environmental Record in Glaciers and Ice Sheets (eds. H. Oeschgers and Langway, Jr.). Wiley, New York, pp. 363—377. 

In glaciers and ice sheets or in groundwater flow systems, water may be moved significant distances and elevations from the site where it fell. This is complicated on ice sheets by changes over time in the ice-sheet thickness (Cuffey 2000), and near ice sheets by isostatic effects of the changing ice load. 

Dansgaard W, Oeschger H (1989) Past enviromnental long-term records from the Arctic. In H Oeschger, CC Langway Jr (eds) The enviromnental record in glaciers and ice sheets. Wiley, New York, p 287-317... 

Although the effects of glaciers and ice sheets on fault stability and seismicity had already received some attention, interest in the topic increased significantly with the observation that there are very few earthquakes below Greenland and Antarctica (Johnston 1987). The analysis indicated that as the ice load increases on the crust, both... 

Improved models of glacially induced seismicity will allow better prediction of what may happen as glaciers and ice sheets decrease in the current global warming trend. The evidence for current crustal scale deglaciation related seismicity is scarce but it may increase in the next century, emphasizing the need for better seismic hazard estimates in the vicinity of thinning ice sheets. 

Crutzen, P.J. Briihl, C., 1989 The Impact of Observed Changes in Atmospheric Composition on Global Atmospheric Chemistry and CUmate , in Oeschger, H. Langway, C.C. (Eds.) The Environmental Record in Glaciers and Ice Sheets, Dahlem Konferenzen 1988 (Chichester WUey) 249-266. 

---