Unit 7 – Glacier National Park Glacier, Glaciers and Glaciation: The Ice Really Was Bigger Bear Grass (really a lily, not a grass) blooming in a glacier-carved but now glacier-free cirque along Going- to-the-Sun Road, Glacier National Park, Montana. All photos by R. Alley, except for some of the Alaska pictures, which are by either R. Alley, C. Alley, J. Alley or K. Alley, and we’re not sure on some of them because we kept trading cameras.

Unit 7 – Glacier National Park Glacier-carved scenery, Logan Pass, Glacier National Park.

Unit 7 – Glacier National Park Cameron Falls, Waterton Lakes, Alberta, Canada (Glacier-Waterton Lakes International Peace Park). The rocks were folded by mountain-building, and the waterfall follows the bent layers.

Unit 7 – Glacier National Park Female bighorn sheep, Glacier National Park. In search of salt, she was going from car to car, licking steering wheels where perspiring hands had left deposits.

Unit 7 – Glacier National Park Bighorn sheep. This ram was over the border in Canada, but surely has relations in Glacier.

Unit 7 – Glacier National Park Mountain goats are aptly named. Glacier National Park.

Unit 7 – Glacier National Park Glacially carved “paternoster” lakes, Glacier National Park.

Unit 7 – Glacier National Park Glacially truncated cliff. The ridge on the left was cut off by a glacier that reached at least as high as the sunlit peak, and that flowed over the point where the photographer stands. Glacier National Park.

Unit 7 – Glacier National Park Meltwater stream entering lake, surface of the Greenland Ice Sheet. At higher elevation, the ice-sheet surface is just snow. Such ice sheets now cover 1/10 of the Earth’s land, but during the last ice age covered almost 3 times more.

Unit 7 – Glacier National Park Caribou on the surface of the Greenland ice sheet, here about 1 mile from the edge, avoiding mosquitoes. Healed crevasses are evident. This is in the ablation zone, and meltwater plus wind-blown dust have dulled the white snow.

Unit 7 – Glacier National Park Bald eagle (arrow) on toe of Margerie Glacier, Glacier Bay National Park, Alaska. Glaciers can be large. Glacier ice is blue, as seen here, for the same reasons that water is blue (preferential absorption of red by water molecules).

Unit 7 – Glacier National Park Bald eagle, Sitka, Alaska, near Glacier Bay National Park, in case you wanted to know what the bald eagle in the previous picture looks like. Mostly, this is an excuse to stick in a cool picture.

Unit 7 – Glacier National Park Iceberg behind float-plane propeller, Northwest Fjord, east Greenland. The berg reaches about 400 feet above the water, and is close to one-half-mile long.

Unit 7 – Glacier National Park Harbor seal on very small iceberg, Glacier Bay National Park, Alaska. Glaciers lose mass either by melting, or by calving icebergs.

Unit 7 – Glacier National Park Rainbow above iceberg, Scoresby Sound, NE Greenland National Park. Icebergs are highly relevant to the study of glaciers and ice ages, but we’re not above sticking in pictures primarily because they’re pretty.

Unit 7 – Glacier National Park Fulmar in front of sea ice, NE Greenland National Park. Sea ice is frozen ocean water, usually less than feet thick. Icebergs calve from glaciers formed from snowfall, and can be more than 1000 feet thick and the size of small states.

Unit 7 – Glacier National Park Marble Island, in Glacier Bay National Park, Alaska, was scoured smooth by glaciers, and is now home to numerous sea lions.

Unit 7 – Glacier National Park An immature bald eagle (arrowed) concerns the gulls and ravens of South Marble Island, a glacially scoured rock in Glacier Bay National Park, Alaska.

Unit 7 – Glacier National Park The deep, glacially carved fjords of Glacier Bay National Park and surrounding Alaska are home to humpback whales and other charismatic macrofauna (big, cute critters).

Unit 7 – Glacier National Park Raised beaches form a bulls-eye on this small island in east Greenland. Melting of ice sheets raised global sea level at the end of the ice age, but some regions that had been depressed under the former ice sheets rebounded faster than the sea rose, raising beaches out of the water.

Unit 7 – Glacier National Park Satellite image of Chesapeake Bay. Geological study of the Bay and its surroundings confirms what you can see by inspection: the bay is a drowned river valley, indicating either that sea-level rose or the land fell fairly recently (mud is filling the bay; if the change happened a long time ago, the bay would be filled). Similar features along many coasts, including those being raised tectonically, show that sea level rose rather than the land falling. heselit.jpg