ESC 1000 Earth Science Tarbuck’s 11th-12th-13th Ed.

 Chapter 6: Glacier, Deserts, and Wind 53 Points


1.      Ablation – A general term for the loss of ice and snow from a glacier.

2.       Abrasion- The grinding and scraping of a rock surface by the friction and impact of rock particles carried by water, wind, or ice.

3.       Alluvial fan- Unconsolidated sediment deposited by a stream.

4.       Alpine glacier- A glacier confined to a mountain valley, which in most instance has previously been a stream valley.

5.       Aręte- A narrow knife like ridge separating two adjacent glaciated valleys.

6.       Barchan Dune- A solitary sand dune shaped like a crescent with its tips pointing downward.

7.       Barchanoid Dune- Dunes forming scalloped rows of sand oriented at the right angle to the wind. This form is immediate between isolated barchans and extensive waves of transverse dune. 

8.       Blowout- A depression excavated by the wind in easily eroded deposits.

9.       Cirque- An amphitheater-shaped basin at the head of a glaciated valley produced by frost wedging and plucking.

10.   Crevasse- A deep crack in the brittle surface of a glacier.

11.   Cross beds- sloping layers of sand forming layers inclined in the direction the wind is blowing.

12.   Deflation- The lifting or removal of loose material by wind.

13.   Desert pavement- A layer of coarse pebbles and gravel created when wind removed the finer material.

14.   Drumlin- A streamline asymmetrical hill compose of glacial till. The steep side of the hill faces the direction from which the ice advanced.

15.   End moraine- A ridge of till marking a former position of the front of a glacier.

16.   Ephemeral stream – A stream that is usually dry because it carries water only in response to specific episodes of rainfall. Most desert streams are of this type.

17.   Esker- Sinuous rigid composed largely of sand and gravel deposited by a stream flowing in a tunnel beneath a glacier near its terminus.

18.   Fiord- A steep-sided inlet of the sea formed when a glacial trough was partially submerged

19.   Glacial drift- An all-embracing term for sediments of glacial origin, no matter how, where, or in what shape they where deposited.

20.   Glacial erratic- An ice transported boulder the was not derived from bedrock near its present site.

21.   Glacial Striations – scratches and grooves on bedrock caused by glacial abrasion

22.  Glacial Trough- A mountain valley that has been widened, deepened, and straightened by a glacier.

23.   Glacier- A thick mass of ice originating on land from the compaction and recrystalization of snow that shows evidence of past or present flow.

24.   Ground Moraine- A undulating layer of till deposited as the ice front retreats.

25.   Hanging Valley- A tributary valley that enters a glacial trough at a considerable height above its floor.

26.   Horn- A pyramid –like peak formed by glacial action in three or more cirques surrounding a mountain summit.

27.   Ice Cap- A mass of glacial ice covering a high upland of plateau and spreading out rapidly.

28.   Ice Sheet- A very large, thick mass of glacial ice flowing outward in all directions from one or more accumulation centers.

29.  Ice Shelf – it is a large , relatively flat mass of floating ice that extends seaward from the coast but remain attached to the land along one of the shores

30.  Interior drainage- A discontinuous pattern of intermittent streams that do not flows to the ocean.

31.    Kame- A steep-sided hill composed of sand and gravel originating when sediment is collected in openings in stagnant glacial ice.

32.   Kettle holes – depressions crated when blocks of ice become lodged in glacial deposits and subsequently melted.  

33.   Lateral Moraine- A ridge of till along the side of an alpine glacier composed primarily of debris that fell to the glacier from the valley walls.

34.   Loess- Deposits of windblown silt, lacking visible layer generally buff-colored, and capable of maintaining a nearly vertical cliff.

35.   Longitudinal dune- Long ridges of sand oriented parallel to the prevailing wind; these dunes from where sand supplies are limited.

36.   Medical Moraine- A ridge of till formed when lateral moraines from two coalescing alpine glaciers join.

37.   Outwash Plain- A relatively flat, gently sloping plain consisting of materials deposited by meltwater stream in from of the margin of an ice sheet.

38.   Parabolic dune- The shape of these dunes resembles brachans, expect their tips point into the wind; they often form along coasts that have strong on-shore winds, abundant sand, and vegetation that partly cover the sand.

39.   Piedmont Glacier- A glacier that forms when one or more valley glaciers emerge from the confining walls of a mountain valleys and spreads out to create a broad sheet in the lowlands at the base of the mountains.

40.   Playa Lake- A temporary lake in a playa.

41.   Pleistocene epoch- An epoch of the Quaternary period beginning about 1.8 million years ago, and ending about 10,000 years ago. Best known as the time of extensive continental glaciations.

42.   Plucking- The process by which pieces of bedrock are lifted out of a place by a glacier.

43.   Pluvial Lake- A Lake formed during a period of increased rainfall. During the Pleistocene epoch this occurred in some nonglaciated region during period of ice advance elsewhere.

44.   Rock flour- Ground-up rock produced by the grinding of effect of a glacier.

45.   Slip face- The steep, leeward slope of a sand dune; it maintains an angle of about 34 degrees.

46.   Star Dune- Isolated hill of sand that exhibits a complex form and develops where wind directions are variable.

47.   Stratified drift- Sediments deposited by glacial meltwater.

48.   Till- Unsorted sediment deposited directly by a glacier.

49.   Transverse dune- A series of long ridges oriented at the right angle of the prevailing wind; these dunes form where vegetation is sparse and sand is very plentiful.

50.   Valley Glacier- same as alpine glacier which is a glacier confined to a mountain valley, which in most instance has previously been a stream valley

51.   Valley Train- A relatively narrow body of stratified drift deposited on a valley floor by meltwater streams that issue from a valley glacier.

52.   Zone of Accumulation-The part of a glacier characterized by snow accumulation and ice formation. Its outer limits in the snowline.

53.   Zone of Wastage- The part of a glacier beyond the zone accumulation where all the snow from the previous winter melts, as does some the glacial ice.