Glaciers and Deserts

Question 1

Glaciers

Answer 1

Large bodies of ice that move under the influence of gravity

Question 2

True or False: Although glaciers typically move very slowly, they have tremendous competence.

Answer 2

True

Question 3

How glaciers form

Answer 3

Glacial ice forms when more snowfall than cannot melt over a summer builds up year after year. The weight of overlying snow compacts snow at the bottom squeezing the snow into granular ice, which then compacts into solid glacial ice at the bottom.

Question 4

continental glaciers aka

Answer 4

ice sheets

Question 5

the largest and thickest types of glaciers

Answer 5

continental glaciers

Question 6

List the earth’s current continental glaciers

Answer 6

Greenland and Antarctica

Question 7

During which ice age did huge ice sheets extend over much larger areas of North America, Europe, and Asia?

Answer 7

The Pleistocene Ice Age

Question 8

Result of the end of the Pleistocene Ice Age

Answer 8

Those areas that were formerly covered in ice are now rising in response to the missing ice (isostatic rebound)

Question 9

ice caps

Answer 9

large glaciers that cover smaller areas (< 50,000 km2) than ice sheets; they generally occur at high elevations in mountainous areas

Question 10

valley glaciers aka

Answer 10

alpine glaciers

Question 11

Valley glaciers

Answer 11

occupy the same places rivers
would if temperatures were warm enough to sustain liquid water. Ice caps can feed valley glaciers, or valley glaciers can be independent of ice caps.

Question 12

zone of accumulation

Answer 12

where snow collects at the top of a valley glacier

Question 13

zone of wastage

Answer 13

where glacial ice melts and wastes away at the lower (and warmer) end of a valley glacier

Question 14

terminus

Answer 14

the leading edge of a glacier; it can advance, retreat, or remain in one place (equilibrium)

Question 15

advancing glacier

Answer 15

When the glacial ice is moving forward faster than it is melting

Question 16

a glacier in equilibrium

Answer 16

the ice is melting just as
fast as it is moving forward, so the terminus stays put.

Question 17

retreating glacier

Answer 17

melting is happening faster than forward movement, so the terminus “retreats” uphill.

Question 18

glacial erratics

Answer 18

When the glacier melts, the trapped rocks it was carrying are left behind

Question 19

glacial striations

Answer 19

As glaciers scrape against
bedrock, the rocks embedded in them leave parallel scratches

Question 20

glacial till

Answer 20

Since glaciers can pick up
essentially any size of rock, the
deposits they leave behind are
usually a mixture of poorly sorted sediments

Question 21

jökulhlaup

Answer 21

a glacial outwash flood

Question 22

end moraine

Answer 22

A glacial deposit made at the terminus of a glacier

Question 23

terminal moraine

Answer 23

the end moraine of a glacier at its furthest advance

Question 24

Glacial landforms

Answer 24

end moraines

terminal moraines

kames [triangular-ish shaped]

eskers [thin landform (line-looking on a map) lying parallel with the flow of the glacier]

drumlins [torpedo-shaped]

kettle lakes

Question 25

morained produced by alpine glaciation

Answer 25

lateral moraines and medial moraines

Question 26

lateral moraines

Answer 26

form along edges of the alpine glacier where it comes into contact with the steep valley wall.

Question 27

medial moraines

Answer 27

form when two valleys come together, hence it is the junction of two lateral moraines, which together make a moraine in the center of the glacier

Question 28

Landforms from Alpine Glaciation

Answer 28

U-shaped valleys horns cirques hanging valleys arête

Question 29

horns

Answer 29

sharp tops on mountain peaks that form because of opposing glaciers cutting into the mountainside

Question 30

cirques

Answer 30

deep bowl-shaped amphitheaters formed by valley glaciers

Question 31

arête

Answer 31

If two cirques are next to each other, they create a sharp ridge

Question 32

hanging valleys

Answer 32

[valleys that suddenly stop and empty into a u-shaped valley]; they're common in areas formerly covered by alpine glaciers

Question 33

deserts

Answer 33

an area/region that recieves less than 25 cm of precipitation per year

Question 34

the world's largest desert

Answer 34

Antarctica

Question 35

why deserts form

Answer 35

Can be one or a combination of these factors: 1. Lack of rain due to dominant high pressure systems. 2. Distance from an ocean. 3. Rain shadow effect. [clouds are emptied as they go over mountains and enter the other side (that needs rain) dry] 4. Cold ocean currents

Question 36

desert landforms

Answer 36

desert pavement, plateaus, mesas, buttes, bajada, playa, ventifact, inselberg

Question 37

desert pavement

Answer 37

a mixture of sand and gravel that covers desert floors

Question 38

plateaus, mesas, and buttes

Answer 38

[flat-topped] landforms that are capped by a resistant layer of rock, (in order of largest to smallest)

Question 39

bajada

Answer 39

when multiple alluvial fans overlap

Question 40

playa

Answer 40

a shallow, ephemeral lake that can be found in a flat valley between mountain ranges. When there is water, it’s very shallow and often very salty

Question 41

ventifact

Answer 41

A rock that has been polished by wind abrasion

Question 42

inselberg

Answer 42

the remnant of a mountain protruding out of its own erosional products.

Question 43

the slopes of sand dunes

Answer 43

stoss and lee slopes [wind brings sand etc. up the stoss slope, which then deposits it on the lee slopes]

Question 44

the angle of repose

Answer 44

the angle at which the lee slope lies (for dry sand it's ~32 degrees)

Question 45

cross-beds

Answer 45

the angled layers within sand dunes

Question 46

[types of sand dunes]

Answer 46

[barchan star transverse parabolic longitudinal]