CHAPTER 17 Key Terms
Match each of the terms on the left with its definition on the right. Click on the term first and then click on the matching definition. As you match them correctly, they will move to the bottom of the activity.
active layer alpine glacier arête cirque cirque glacier col crevasse drumlin equilibrium line esker fjord glacial advance glacial erratic glacial ice glacial polish glacial retreat glacial striation glacial valley glacier glacier mass balance horn iceberg ice cap ice sheet ice shelf kame- loess moraine moulin nunatak outlet glacier outwash plain paternoster lake periglacial permafrost piedmont glacier plucking recessional moraine roche moutonnée tarn terminal moraine till toe valley glacier | A heap of unsorted sediments deposited by a glacier. The difference between inputs to a glacier that increase its ice volume and losses of ice that decrease its ice volume. (or glacial trough) A U- (pronounced moo- Ice with an air content of less than 20%. A glacier that occupies a mountain valley. (or snowline) The elevation at which a glacier’s ice accumulation and ice loss are equal over the period of one year. The portion of an ice sheet or an outlet glacier that extends over the ocean. One of a series of small lakes that form behind glacial steps in a glacial valley. Of or referring to unglaciated areas at high latitudes and high elevations subject to persistent and intense freezing. Any debris deposited by a glacier without the influence of running water. A flat area of sediments deposited by glacial outlet streams. A long ridge of sorted sand and gravel deposited by a subglacial stream. A moraine that marks the farthest advance of a glacier’s toe. The leading edge and lowest elevation of a glacier. A bowl- The forward (usually downslope) movement of a glacier’s toe. A glaciofluvial landscape dominated by irregular mounds and shallow depressions or lakes. A glacier that forms at the head of a valley. An elongated hill formed by a moving ice sheet. A large mass of ice that is formed from the accumulation of snow and flows slowly downslope. (pronounced nuh- A smoothed bedrock surface resulting from glacial abrasion. The process by which a glacier pulls up and breaks off pieces of bedrock as it moves downslope. A groove gouged into the surface of bedrock by glacial abrasion. A glacier that flows out of an ice sheet or ice cap through a constricted valley, usually into the ocean. Any glacier found in a mountainous area. A steep, pyramid- Cracks that develops in the top 60 m of a glacier. The upslope movement of the toe of a glacier. A large block of ice that breaks from the toe of a glacier or an ice shelf and floats in the ocean or a lake. A dome of ice that sits over a high mountain region and has an extent of 50,000 km2 (19,300 m2) or less. Ground that remains below freezing continuously for two years or more. A ridge of till that forms at the toe of a glacier; formed where the glacier pauses as it is gradually retreating upslope. The top layer of permafrost that thaws each summer and refreezes in fall. (pronounced ar- A low area or pass over a ridge formed by two cirque glaciers. A U- (pronounced ROSH moo- (pronounced lehss) Wind- A mountain lake that forms within or just below a cirque. A large boulder transported a long distance by a glacier. A lobe of ice that forms as a valley glacier flows onto a flat plain. A flat sheet of ice that has an extent of 50,000 km2 (19,300 mi2) or more. |