Chapter 17: Glaciers

Question 1

A temporary line marking the elevation where winter snowfall persists throughout the summer; seasonally, the lowest elevation covered by snow during the summer

Answer 1

snowline

Question 2

the frozen portion of earth’s waters, including ice sheets, ice caps and fields, glaciers, ice shelves, sea ice and subsurface ground ice and frozen ground (permafrost)

Answer 2

cryosphere

Question 3

large mass of perennial snow and ice that typically shows movement in response to gravity

Answer 3

glacier

Question 4

granular, partly compacted snow that is intermediate between snow and ice

Answer 4

firn

Question 5

masses of ice confined within a valley - originally formed by stream action

Answer 5

Valley glacier

Question 6

a scooped-out, amphitheater-shaped basin at the head of an alpine glacier valley; an erosional landform

Answer 6

cirque

Question 7

forms when several valley glaciers pour out of their confining valleys and coalesce at the base of a mountain rang

Answer 7

Piedmont glacier

Question 8

a glacier that ends in the sea

Answer 8

tidewater glacier (aka tidal glacier)

Question 9

a process in which pieces of ice break free to form floating ice masses known as icebergs

Answer 9

calving

Question 10

a continuous mass of unconfined ice, covering at least 50 000km2

Answer 10

ice sheet (Greenland and AA)

Question 11

these are at the edges of ice sheets - they are permanent masses of ice that extend into the sea

Answer 11

ice shelves

Question 12

a large, dome-shaped glacier, less extensive than an ice sheet although it buries mountain peeks and the local landscape; generally, less than 50 000km2

Answer 12

ice cap

Question 13

the least extensive form of a glacier, with mountain ridges and peaks visible above the ice; less than an ice cap or ice sheet

Answer 13

ice field

Question 14

openings int he ice that resemble sinkholes

Answer 14

moulins

Question 15

where the accumulation zone ends: the ___ line

Answer 15

firn line

Question 16

the property that will determine whether the glacier advances (grows larger) or retreats (grows smaller)

Answer 16

the glacier’s mass balance

Question 17

(temperate) The basal ice is frozen, or stuck to the underlying surface.

Answer 17

cold-based ice

Question 18

(temperate) not frozen to the bed and is able to slide across the surface, with the rate of basal slip varying with temperature and the presence of any lubricating water beneath the ice

Answer 18

Warm-based ice (alpine!)

Question 19

“to freeze” or “to re-gel” (unevenness in the landscape beneath the ice may cause the pressure to vary, melting some of the basal ice by compression at one moment, only to have it refreeze later

Answer 19

ice regelation

Question 20

cracks. vertically formed in a. flowing alpine glacier or ice stream

Answer 20

crevasses

Question 21

when rocks are lying in storage locations with no obvious sign of how they arrived there - an early clue to the glacial plucking that occurred during times when blankets of ice covered the land
(that rock DON’T BELONG THERE WTH MAN)

Answer 21

glacial erratics

Question 22

this produces a smooth surface on exposed rock, which shines with glacial polish when the glacier retreats

Answer 22

abrasion

Question 23

the general term for all glacial deposits, both unsorted (till) and sorted (stratified drift)

Answer 23

glacial drift

Question 24

unsorted and unstratified debris that’s deposited not he ground as the glacier melts (from ice)

Answer 24

till

Question 25

marginal glacial deposits (lateral, medial, terminal, ground) of unsorted and unstratified material

Answer 25

moraine

Question 26

debris transported by a glacier that accumulates along the sides of the glacier and is deposited along these margins

Answer 26

lateral moraine

Question 27

when two glaciers with lateral moraines join is called a ___ moraine

Answer 27

medial

Question 28

the LAST moraine. eroded debris that is dropped at the glacier’s farthest extent

Answer 28

terminal moraine

Question 29

also called a ground moraine, a deposition of till that forms behind a terminal moraine as the glacier retreats and is generally spread widely across the ground surface, creating irregular topography but not the characteristic ridges of other moraines

Answer 29

till plains

Question 30

hills of deposited till that are streamlined int he direction of ice sheet movement, with blunt and upstream and tapered end downstream

Answer 30

drumlins

Question 31

multiple drumlins is a ___

Answer 31

drumlin swarm

Question 32

sediments deposited by glacial meltwater sorted by size

Answer 32

stratified drift

Question 33

an area of glacial stream deposits of stratified drift with meltwater-fed, braided and overloaded streams; occurs beyond a glacier’s morainal deposits

Answer 33

outwash plaina

Question 34

a sinuously curving, narrow deposit of coarse gravel that forms along a meltwater stream channel, developing in a tunnel beneath a glacier

Answer 34

Esker

Question 35

a small hill of poorly sorted sand and gravel that accumulates in crevasses or in ice-caused indentations in the surface

Answer 35

kame

Question 36

sometimes an isolated block of ice, perhaps more than a km across, remains on a ground moraine, on an outwash plain, or on a valley floor after a glacier has retreated

Answer 36

kettle or kettle lake

Question 37

cold-climate processes, landforms, and topographic features along the margins of glaciers, past and present; periglacial characteristics exist on more than 20% of Earth’s land surface; includes permafrost, frost action, and ground ice

Answer 37

periglacial landscapes

Question 38

perennially frozen ground

Answer 38

permafrost

Question 39

the region of severest cold and is perennial, roughly poleward of the -7°C mean annual temperature isotherm

Answer 39

continuous permafrost

Question 40

gradually coalesce poleward of the -1°C mean annual temperature isotherm, toward the continuous zone

Answer 40

discontinuous permafrost