A glacier is a perennial mass of ice, and possibly firn and snow, originating on the land surface by the recrystallization of snow or other forms of solid precipitation and showing evidence of past or present flow (Cogley et al. 2011, Glossary of Glacier Mass Balance and Related Terms). So it's basically formed from snow accumulating for many years.

Interaction between glaciers and atmosphere is very complex and follows different directions. Climate influences ice (e.g. warming >>> melting) and ice influences climate (e.g. melting >>> lower albedo >>> more energy absorption >>> more warming). Google the latest IPCC report, cryosphere chapter should introduce you to the basic concepts.

If it comes to 10Be: it is produced as a result of interaction between cosmic rays and nitrogen and oxygen, so it is related to solar activity, for which we have chronologies. Concentration of 10Be in your ice sample may give you a clue at what point of solar activity was it formed. With use of chronology you can place its formation in time.

Best,

Jakub Malecki

Besides what Jakub mentioned, 10Be is also used to date erratics left by glaciers and this helps to determined the age of former glacier extent. The idea is that the boulder had no 10Be at the time of deposition and this isotope is later produced by cosmic radiation in the surface layer. Hence, the amount of 10Be is a measure of time. I have included a link to an open access article that described the method in more detail.

http://quaternary-science.publiss.net/issues/57/articles/782

Thought this provided good info - http://wattsupwiththat.com/2009/03/17/beryllium-10-and-climate/

Beryllium-10 is an isotope that is a proxy for the sun’s activity. Be10 is produced in the atmosphere by cosmic ray collisions with atoms of oxygen and nitrogen. Beryllium 10 concentrations are linked to cosmic ray intensity which can be a proxy for solar strength.

One way to capture earth’s record of that proxy data is to drill deep ice cores. Greenland, due to having a large and relatively stable deep ice sheet is often the target for drilling ice cores.

Isotopic analysis of the ice in the core can be linked to temperature and global sea level variations. Analysis of the air contained in bubbles in the ice can reveal the palaeocomposition of the atmosphere, in particular CO2 variations. Volcanic eruptions leave identifiable ash layers.

One of the problems of 10Be dating of erratic material is that it is expected to be inside the body of the glacier and then as it melts out it becomes exposed to the cosmic rays, which may give us the time of the melting out. But in fact the boulder could be taken not from the bedrock but fall o its surface from the surrounding slopes and then be transported on the surface of the glacier, being exposed to cosmic rays long before the deposition in moraine.