Chapter 19, Problem 1LC

To determine

To compare: Mountain glaciers and continental ice sheets.

Answer to Problem 1LC

Mountain glaciers are found high in a mountainous valley while the continental ice sheets extend over the continental landmass such as Greenland. Mountain glaciers are only found in high-mountain tops whereas the continental ice sheets are found at the Earth’s poles regardless of the elevation.

Explanation of Solution

Glaciers are moving mass of ice under the influence of gravity.

• A. MOUNTAIN GLACIERS

There are two kinds of mountain glaciers, highland ice fields and alpine glaciers.

• a) Highland Icefield is an unconfined ice sheet in high-mountainous regions, which evolve into valley glaciers and piedmont glaciers. These ice sheets cover hundreds or thousand square kilometers.

1. Valley glacier is a long and narrow river of ice that is spilling out of its originating basin and travels down to the valley.

2. Piedmont glacier is a valley glacier that reaches to the valley mouth and fans out extensively over the flat land beyond the confining valley walls.

b) Alpine glacier – An individual glacier forms adjacent to a mountain crest line and normally moves down the valley for some distance. They usually form at the heads of the valleys. An alpine glacier typically originates out of its basin and flows down-valley by forming a valley glacier, and can also reach the valley mouth and give a piedmont glacier.

1. 1. Cirque glacier is a small alpine glacier confined to its cirque basin and does not move down to the valley.

• B. CONTINENTAL ICE SHEETS

1. a) Ice sheet – A massive blanket of ice that completely engulfs the landmass underneath about hundreds or thousands of meters depth. The depth of the ice sheets are greater in its interior and thin out at the outer edges. These are formed in non-mountainous areas of continents. There are only two true ice sheets currently, in Antarctica and Greenland.
2. b) Outlet glacier - A long tongue-like feature of ice around the edges of an ice sheet that extends between rimming hills to the sea. Ice shelf is a shelf of ice that is reaching the ocean that protrudes over the sea along a massive front. Icebergs are formed from calving of ice chunks from ice shelves and outlet glaciers.