The Last Frontiers

 “land of the midnight sun” ◦ At least one 24 hr. period each year the sun never sets  Bounded by the Antarctic Circle at 66.5* latitude  Huge packs of permanent floating ice defied exploration  Icebergs- jagged chunks of ice broken off from glaciers  Technically, Antarctica is surrounded by 3 oceans (Pacific, Atlantic and Indian), but a band of polar water circles the continent and is much colder and less salty ◦ Some call the Southern Ocean a “fifth” ocean ◦ Ice pack covers the polar water ◦ Ice that breaks off: ice floes ◦ Open water between the floes: lead

 East Antarctica ◦ High plateau covered by ice more than a mile deep ◦ Avg. temp in the interior during coldest months: -94*F ◦ Nothing lives in the interior, but due to extreme cold no snow falls ◦ On Ross Sea, McMurdo Station—largest settlement in Antarctica.  West Antarctica ◦ Ross Sea and Weddell Sea cut in on on either side  Separated from South Pole by the Transantarctic Mountains ◦ Mountainous rather than flat  Highest mountains on continent: Ellsworth Mts.  Solitary mountains called: nunataks ◦ Antarctic Peninsula- most coveted area, extends toward South America

 Captain Cook circled Antarctica looking for the fabled southern continent, but couldn’t get through the ice  American, Russian and English sealing ships each claim to be the first to sight Antarctica  Norwegian man, Henryk Johan Bull, became the first to step foot on the land  Roald Amundsen plants a Norwegian flag at the South Pole, at the same time British Robert Scott was struggling to reach the site—he did, but entire crew died on the way back

 Foreign powers began establishing bases in Antarctica in the 1940s  Scientists from around the world pleaded for the area to remain neutral and free to science  From , 12 nations worked together to set up 60 stations and agreed to share their findings ◦ All signed the Antarctic Treaty- agreement to ban military bases and weapons testing ◦ In 1991, the treaty was renewed, more nations signed on and it was termed “indefinite” in its time frame  Fears: ozone hole above Antarctica ◦ 90% of Earth’s ice is locked up in ice caps ◦ if ice caps were to melt seal level would rise around the world, sinking many cities and islands

 Undersea Landscape ◦ Features pg. 589 ◦ Continental Shelf- submerged edges of land ◦ Continental Slope- edge of shelf, drops off sharply ◦ Photic zone- enough light for photosynthesis, upper 700 feet of the ocean, most of the fish we eat live here  Midsea- mesopelagic ft. deep  Deep sea- bathypelagic- from mid sea down ◦ Ocean Basins- floor of ocean, stretched between continents ◦ Abyssal Plains- flattest areas on earth, make up ½ the ocean floor ◦ Trenches- deep canyons, Pacific has the most, Mariana Trench is the deepest (35,000 ft. deep) ◦ Oceanic ridges- mountains that sometimes reach the surface to create islands, Iceland is one such island ◦ Seamounts-underwater volcanoes, new ones can form like Surtsey ◦ Deep sea vents- can spew hot lava or sulfur into the dark waters, usually along fracture zones where earthquakes have happened

 20 th century explorers ◦ First humans to go below the photic zone were William Beebe and Otis Barton in 1930 ◦ Frenchman Jacques Cousteau invented the Aqua- Lung in 1943 or self contained underwater breathing apparatus (SCUBA), made many explorations, filmed documentaries ◦ Robert Ballard- using a device named Argo discovered the wreckage of the Titanic in 1985

 During 17 th century, nations declared 3-6 miles wide strip of water near coast to be Territorial Waters, beyond that was the High Seas –open to all  US supports the “freedom of the seas” idea today, but has become complicated as nations extend their territorial waters  UN recognizes 200 mile Exclusive Economic Zone (EEZ) for right to fish and drill for oil in the respective zone