Glaciers Flashcards
thick mass of ice originating on land from the compaction and recrystallization of snow.
Glaciers
scientific study of glaciers or more generally ice and natural phenomena that involve ice
Cryology/ Glaciology
small glaciers that form valleys
Valley Glacier
Enormous glaciers that can cover continents
Ice Sheets
are large flat masses of floating ice that extend seaward from the coast
Ice Shelves
mass of glacial ice covering a high upland or plateau
Ice Caps
a tongue of ice normally flowing rapidly outward from an ice cap or ice sheet
Outlet Glaciers
forms when one or more valley glaciers emerge from the confining walls of mountain valleys
Piedmont Glaciers
a granular type of ice
Firn
a process when slope is present glaciers may slide over their underlying surface
Basal Slip
a type of deformation that takes place in response to stress
Plastic Flow
zone where ice melts
Zone of Wastage
elevation above which snow remains throughout the year
Snowline
process by which pieces of bedrocks are lifted out of place by a glacier
Plucking
the grinding and scrapping of a rock surface by the friction and impact of rock particles carried by water, wind or ice
Abrasion
scratches and grooves of bedrocks caysed by glacial abrasion
Glacial striation
a mountain valley that has been widened, deepened and straightened by a glacier
U-Shaped Glacial trough
a tributary valley that enters a glacial trough at considerable height above the floor of trough
Hanging Valleys
a chain of small lakes in a glacial trough that occupy the basins created by glacial erosion
Pater Noster lake
a circular hollow cut into bedrock during glaciation. Side and back wall are steep but front walls open downward
Cirque
a small lake in a cirque
tarn
are deep, steep sided inlets of the sea that are present at high latitudes where mountains are adjacent to the ocean
Fjord
a sharp-crested serrate ridge separating the heads of opposing valleys that formerly were occupied by Alpine glaciers
Aretes
results when glaciers erode three or more aretes, usually forming a sharp-edged peak
Horns
an asymmetrical knob of bedrock formed when glacial abrasion smoothen the gentle slope acing the advancing ice sheets and plucking steepeneds the opposite side as the ice overrides the knob
Roche Moutonnees
deposited as glacial ice melts and drop its load or rock fragments
Till
not deposited directly by glaciers, rather they reflect the sorting action of glacial melt water
Stratified Drift
an ice transported boulder that was not derived from the bedrock near its present side
Glacial Erratics
a ridge of till along the sides of a valley glacier composed primarily of debris that fell to the glacier from the valley walls
Lateral Moraine
a ridge of till formed along when lateral moraines from two coalescing valley glaciers join
Medial Moraine
a ridge of till marking the former position of the front of the glacier
End Moraine
an undulating layer of till deposited as the ice front retreats
Ground Moraine
a relatively flat, gently sloping plain consisting of materials deposited by melt water streams in front og the margin of an ice sheets
Outwash Plain
a relatively narrow body of stratified drift deposit on a valley floor by melt water streams that issue from the terminus of a valley glacier
Valley Train
depression created when blocks of ice becomes lodged in glacial deposits and subsequently melt
Kettles
a streamlined asymmetrical hill composed of glacial till
Drumlins
sinuous ridge composed largely of sand, gravel deposited by a stream flowing in a tunnel beneath a glacier near its terminus
Eskers
a steep sided hill composed of sand and gravel, originating when sediments collected in openings in stagnant glacial ice
Kames
