Unit 3: glacial and periglacial landscapes

Question 1

where do glaciers from and where are they in canada

Answer 1

• cold and wet enough
• coldness can come from altitude or elevation
• not all the tundra is glaciated because of a lack of precipitation
• in canada there are glacier in the arctic region (north of nunavut), coastal regions (in the locations where it is cold enough) and the rockie mountains

Question 2

explain glacier mass balance

Answer 2

• the net accumulation and ablation
• the accumulation of a glacier occurs with snowfall and other moistures and the ablation zone is the mass lost through melting and other processes

Question 3

what is the difference between warm and cold based glaciers

Answer 3

• cold ice: ice at the bottom of the glacier is blow pressure melting point and frozen to the glacier bed. occurs where surface experiences very low winter temperatures
• warm ice: ice at the bottom of the glacier is close enough to pressure melting point to contain water. water lubricates the ice enabling it to flow much more quickly and cause erosion because water at the base facilitating slip and erosion

Question 4

mark were the laurentide ice sheet was 21,000, 14,000 and 7,000 years ago

Answer 4

• look at the picture

Question 5

outline current glaciers in canada

Answer 5

• north most island in nunavut
• side of yukon and a lil bit of BC (in the north and west)
• rockies

Question 6

five erosion landforms created by alpine glaciation

Answer 6

• striations: parallel marks
• criques: dip in the mountain side were mroe roc was carved out than the surrounding area
• roch mountonee: asymmetrical erosion of a rock creating a lee side
• fjords: a narrow inlet with steep cliffs (with a little river in the bottom)
• hanging vallyes: a former glacier valley that moved into the upper part of a U shaped glacier valley with a higher floor than the main valley

Question 7

five depositional landforms created by alpine glaciation

Answer 7

• lateral moraine: moraine found on the walls of a valley glacier
• terminal moraine: a moraine found at the end of a glacier marking its max advance
• till: deposits of fine sediment from a receding glacier
• erratic: random boulder placed from a melting glacier depositing them in a seemingly random location
• outwash plain: a flat plain with sediment left behind from the scraping and depositing of a receding glacier

Question 8

two erosional landforms created by continental glaciation

Answer 8

• rouch moutonee: asymmetrical erosion of a rock creating a leeward side of a rock
• striations: parallel marks on the rock from the bottom till in the glacier being scraped across with enormous force

Question 9

five depositional landforms created by continental glaciation found in canada

Answer 9

• drumlin: elongated hill from the ice acting on unconsolidated till
• kames: deposits of glacial till in an irregularly shaped hill
• kettles: depressions that are filled with deposited ice that eventually melts. a pit
• eskers: a long ridge of sand and gravel deposited by a receding glacier
• delta: deposition of sediments carried out by water making triangular shape

Question 10

define periglacial climate

Answer 10

• cold climate
• regardless of the presence of glaciers
• generally described landscapes where the ground is perennially frozen

Question 11

what is the difference between continuous and discontinuous permafrost

Answer 11

• continuous: perennial and found in the northern half of the territories (not in the provinces)
• discontinuous: occurs in patches until it disappears completely at IC MAT isotherm

Question 12

what is the active layer in permafrost

Answer 12

• a zone of seasonally frozen ground that exists between subsurface of permafrost layer and ground surface
• the portion of the soil above the permafrost that thaws and freezes seasonally

Question 13

what are taliks

Answer 13

• bare unfrozen areas of variable shape within or below the permafrost
• they area a result of heat from lakes and other bodies of standing water. closed talkis develop for a number of reasons including lake drainage

Question 14

how does the active layer vary with latitude

Answer 14

• depth and thickness of the active layer corresponds to changes in climate (air, temp, slope, vegetation, drainage, snow cover, soil, water content)

Question 15

rock falls

Answer 15

• exposed rock outcrops are common in periglacial regions
• extreme variations in temperature can accuse the fracturing of rock along natural bedding planes and joints leading to rock falls
• this fracturing is mainly due to frost wedging and insolation weathering