Located at the southernmost tip of Ross Island is Antarctica's largest science base, McMurdo Station. Built on New Zealand's Antarctic claim, McMurdo has been a polar base for American scientists and support personnel for over 50 years.
Historically, Ross Island is known as the jumping-off point for polar exploration ever since Ernest Shackleton and Robert Scott began their race to the South Pole in the early 20th century. Today, according to Texas A & M University, Ross Island is the farthest-south landmass accessible by ship, making McMurdo's harbor the world's southernmost seaport.
Volcanically formed, Ross Island's geologic and geographic features pose unique challenges in sustaining a year around polar science station. Its western shoreline opens to McMurdo Sound, a 2500 mile expanse of the Ross Sea. All but 10% of the Sound's total shoreline freezes annually with nearly 10 feet of sea ice. On Ross Island's southern border, is the Antarctic polar plateau, which brings strong katabatic flows into McMurdo Station itself. These winds bring temperatures that range anywhere between -59˙ - 30˙F (without wind chill).
These factors combine to make the air support into McMurdo Station very strategic. Every August, a frozen airstrip is built on the smooth annual sea ice. Rising temperatures however, will force its relocation up onto the McMurdo Ice Shelf. Here, the 500 feet of glacial ice can withstand the remaining temperature fluctuations prevalent throughout the remainder of the polar austral summer. So, why don't they build the runway on the ice shelf to begin with? The sea ice runway is not only closer to McMurdo Station but it also takes several weeks to successfully lay a 10-mile long fuel line out to the new airstrip.