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 | The leading edge and lowest elevation of a glacier. A glacier that flows out of an ice sheet or ice cap through a constricted valley, usually into the ocean. A glacier that occupies a mountain valley. A long ridge of sorted sand and gravel deposited by a subglacial stream. A low area or pass over a ridge formed by two cirque glaciers. The forward (usually downslope) movement of a glacier’s toe. (pronounced nuh- A lobe of ice that forms as a valley glacier flows onto a flat plain. A steep, pyramid- Any glacier found in a mountainous area. (pronounced moo- A U- A flat area of sediments deposited by glacial outlet streams. A bowl- (pronounced lehss) Wind- The portion of an ice sheet or an outlet glacier that extends over the ocean. A smoothed bedrock surface resulting from glacial abrasion. The upslope movement of the toe of a glacier. A glaciofluvial landscape dominated by irregular mounds and shallow depressions or lakes. A glacier that forms at the head of a valley. (pronounced ROSH moo- A dome of ice that sits over a high mountain region and has an extent of 50,000 km2 (19,300 m2) or less. 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. A heap of unsorted sediments deposited by a glacier. Ice with an air content of less than 20%. A large mass of ice that is formed from the accumulation of snow and flows slowly downslope. (pronounced ar- (or glacial trough) A U- A large boulder transported a long distance by a glacier. Ground that remains below freezing continuously for two years or more. A flat sheet of ice that has an extent of 50,000 km2 (19,300 mi2) or more. A mountain lake that forms within or just below a cirque. Any debris deposited by a glacier without the influence of running water. Cracks that develops in the top 60 m of a glacier. An elongated hill formed by a moving ice sheet. 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. The process by which a glacier pulls up and breaks off pieces of bedrock as it moves downslope. (or snowline) The elevation at which a glacier’s ice accumulation and ice loss are equal over the period of one year. A moraine that marks the farthest advance of a glacier’s toe. Of or referring to unglaciated areas at high latitudes and high elevations subject to persistent and intense freezing. A groove gouged into the surface of bedrock by glacial abrasion. The difference between inputs to a glacier that increase its ice volume and losses of ice that decrease its ice volume. One of a series of small lakes that form behind glacial steps in a glacial valley. |