Final answer:
The surface area of Antarctica changes due to the seasonal expansion and shrinkage of its ice sheet, influenced by temperature fluctuations, and climate change. During winter, the ice extends, and in summer, melting reduces its area. Climate change may lead to faster melting and sea level changes.
Step-by-step explanation:
The surface area of Antarctica fluctuates due to the seasonal expansion and shrinking of its ice sheet. The Antarctic ice sheet, which covers about 98 percent of the continent and holds approximately 70 percent of the earth's fresh water, can double in size during the winter season as sea ice extends from the coastline. During summer, the sun shines 24 hours a day, increasing temperatures and causing some of the ice to melt and contract the surface area.
Factors contributing to these fluctuations include climate change and variations in precipitation. With rising global temperatures due to an increase in greenhouse gasses, Antarctic ice may melt more rapidly, suggesting a potential long-term decrease in ice sheet size and an increase in sea levels. Additionally, the tilt of the earth's axis affects the angle of incoming solar radiation, influencing the amount of melting and refreezing of the ice sheet seasonally.
Moreover, the ice flow, aided by erosion and sediment movement at the ice edges and beneath the ice sheet affecting its mass and dynamics, contributes to the fluctuations. Given Antarctica's status as a desert with minimal precipitation and its extreme climate, there is no permanent human habitation, but the continent's icy environment is critical for reflecting sunlight and regulating the earth's temperature.