Question

Hi,

Could you please have a look at the satelite image of Gangotri Glacier? it can be found if you type: " Retreat of the Gangotri glacier" in google images.

Please tell me how to measure the amount of advance or retreat of the glacier between 1780-1935, 1935 - 1964, 1964 - 1971 and 1971 - 2001 in metres per year.

I am unsure where should i take my measurements from.. i mean from which point of the equilibrium line, especially on the curvy lines as in 1971? Should I take it from the highest, or lowest point?

Also, what are the reasons for the changes in rates of advance/retreat since 1780?

Is there any advance of the terminus at all? As to me it looks like, the glacier is constantly retreating..

Please help!