Cryosphere last Part

Question 1

landscapes around glaciers are described as ___

Answer 1

periglacial

Question 2

____ is ground (sediment or regolith) that remains frozen for __ or more years

Answer 2

permafrost
2

Question 3

T/F
permafrost can be up to 3km thick

Answer 3

false
1m- 1500m (in parts of siberia)

Question 4

What is the active layer?

Answer 4

the surface layer of sediment/ rock above the permafrost that thaws seasonally
10cm- 2m thick

Question 5

permafrost is ___, therefore bogs are common above permafrost

Answer 5

impermeable

Question 6

what is it called when the active layer creeps?

Answer 6

solifluction lobes
- creep of the active layer when it is saturated and lies on a slope

Question 7

how do ice wedges form?

Answer 7

• fall: ground may crack as it dries and contracts
• snow blows into cracks
• seasonal melt= the snow in the cracks melts
• when it freezes, ice expands and widens the crack= produces ice wedge
• repeated freeze/thaw cycles widens the wedge (keeps growing)

Question 8

What is patterned ground? (aka polygonal ground)
give an example

Answer 8

geometric patterns that form on surfaces experiencing intense freezing/ thawing
eg. polygonal ground formed by ice wedges

Question 9

pingoes are hills (up to __m high and 800m wide) that are cored by ____

Answer 9

90
ice

Question 10

how do pingoes form?

Answer 10

• form at sites of former lakes (where water was present at surface)
• a lens of water is trapped when the water freezes
• raising of the pingo occurs when this water is pressurized by either:
  1. artesian groundwater from below
  2. the pressure of expanding ice from the sides and below

(both expand the ice, causing land to rise)

Question 11

why does permafrost contain a lot of stored carbon?

Answer 11

it freezes organic matter, preventing it from decaying

Question 12

explain the positive feedback loop of warming and permafrost melting

Answer 12

as permafrost warms and thaws, it returns CO2 and methane to the atmosphere
- this promotes further warming (GHG) = more melting= positive feedback loop

Question 13

what’s another issue associated with permafrost melting?

Answer 13

as it melts, ground stability decreases
- slumps form where permafrost is melting, causing landslides
- what will happen to buildings etc built directly on permafrost when it melts?

Question 14

explain how sea ice forms, using correct terminology

Answer 14

1. frazil ice: small needles of ice form below the freezing point of seawater (-2C)
2. these needles freeze together into either pancake ice (in rough water) or nilas (in calm water)
3. pancake ice or nilas eventually coalesce into continuous ice cover (pack ice)
4. subsequent freezing adds ice to the base, eventually forming solid sea ice

Question 15

sea ice ___ the ocean from the atmosphere
- this cuts off __ exchange
- ice is very reflective (__ albedo) so it reflects light and heat

Answer 15

isolates
heat
high albedo

Question 16

describe the differences between arctic and Antarctic sea ice

Answer 16

Arctic:
- ocean is covered in sea ice
- has perennial ice (multiyear)
- undergoing major changes

Antarctic:
- most of it is seasonal (melts every summer)
- relatively stable over the last several decades
- forms an ice ring around the continent

Question 17

t/f
the planet is warming evenly

Answer 17

false
it is not!
warming is worse in the north (this is why the arctic is undergoing more sea ice changes)

Question 18

as sea ice freezes, ____ is excluded, making the surface ocean water ____

Answer 18

salt
saltier

Question 19

as arctic sea ice shrinks, ocean waters become

Answer 19

less salty
warmer
less dense= slows NADW (north Atlantic deep water)

Question 20

loss of sea ice contributes to “polar (artcic) ____” which is:

Answer 20

amplification
= the northern latitudes experience greater warming
- b/c of albedo (+ feedback loop)

Question 21

There is lots of variability in changes in Antarctic (south) sea ice. Why is this?

Answer 21

the variability is largely driven by major wind pattern changes

Question 22

what is the longterm trend in sea ice extent, age, and volume for the arctic (north) sea ice?

Answer 22

all are decreasing :(

Question 23

Antarctic sea ice:
- forms around a ____ rather than at the ___ (arctic)
- forms at lower ____ so less survives ____
- extremely ____ from one region to another

Answer 23

continent
poles

latitudes
summer melt

variable

Question 24

Sea ice is a very important component of Earth:
- increases surface ____ (more reflective= ___)
- insulates the ocean from ____ ___
- provides a barrier to ___ _____ b/w the ocean and atmosphere
- Artic sea ice is particularly sensitive to ___ ____

Answer 24

• albedo, cooler
• heat loss/gain
• gas exchange
• climate change