Problem 2 [5 point): Ocean level rise due to melting of Greenland ice sheet This question mainly deals with unit analysis. You will need the following facts:

* The Greenland ice sheet has an area of 1.7.10 km?.

* Earth Observation missions (see picture above) have determined that every year the ice
sheet loses 280 Gigatons = 280 102 kg of ice.

(a) Assuming that the density of ice is 1000 kg/m", estimate how much height the ice sheet
loses over an average year hint what are the units of height7].

(b) The mean thickness of the Greenland ice sheet is 2.5 km. How many year will it take the
Ice sheet to disappear? Comment on whether you think this is a reasonable estimate?

(c) Using the fact that the Earth oceans cover 360 • 10 km, estimate how much the melting
of the Greenland ice sheet contributes to sea level rise each year.

(d) Which type of orbit do Earth Observation satellites that measure ice loss use: geostationary or low-Earth orbit? Provide a brief explanation for your answer.