EGS Frank Week 8 Polar Environments Flashcards
1
Q
Overview P1/6
- (1) The polar environments are among the () places on earth but subject to () driven by ().
- (2) The () part of the Cryosphere consists of 1. (), 2. (), and its 3. (), 4. (), 5. (), 6. (), 7. () & 8. ().
- (3) These are not () distributed.
A
- (1) The polar environments are among the least inhabitated places on earth but subject to rapid changes driven by global greenhouse gas emissions.
- The frozen part of the Cryosphere consists of 1. snow, 2. Permafrost, and its 3. active layer, 4. sea ice, 5. ice caps, 6. glacial ice, 7. ice shelf & 8. iceberg.
- These are not equally distributed.
2
Q
Overview P2/6
- (4) The () accumulates the largest () annually, which is roughly () of the earth’s surface.
- (5) The () soils here are () & home to (), which also holds many (), especially ().
- (6) With current () trends, the () is () and releasing () into the ().
A
- (4) The Northern Arctic accumulates the largest aerial extent of snow annually, which is roughly 10% of the earth’s surface.
- (5) The Gelisol soils here are frozen & home to permafrost, which holds many frozen gases, especially methane.
- (6) With current warming trends, the soil is melting and releasing greenhouse gases into the atmosphere.
3
Q
Overview P3/6
- (7) () is also prevalent and subject to (), but also subject to () & () in the () months in the Arctic Ocean.
- (8) This leads to () Arctic Oceans & more ().
A
- (7) Sea ice is also prevalent and subject to strong seasonal cycles, but also subject to warmer summers & ever-decreasing ice cover in the summer months in the Artic Ocean.
- (8) This leads to warming Arctic Oceans & more melting.
4
Q
Overview P4/6
- (9) The Arctic is also home to (), which has a ().
- (10) () enters the () & increases the () of () to the oceans.
- (11) All of these factors contribute to ().
A
- (9) The Artic is also home to Greenland, which has a melting ice cap.
- (10) Meltwater enters the glaciers & increases the flowrates of glacial ice to the oceans.
- (11) All of these factors contribute to sea-level rise.
5
Q
Overview P5/6
- (12) Antartica is a (), the (), ~ () the size of Greenland, and the ().
- (13) It is much () than the Arctic & not subject to () or ().
- (14) Instead, (), which holds back the () & (), are () in () oceans.
A
- (12) Antartica is a continent, the largest ice cap, ~10 times the size of Greenland, and the largest store of global freshwater.
- (13) It is much colder than the Arctic & not subject to surface melting or home to much permafrost.
- (14) Instead, shelf ice, which holds back the glaciers & ice caps are breaking up in warming oceans.
6
Q
Overview P6/6
- (15) This leads to () and ().
- (16) Especially the () is home to breaking ().
- (17) All of these factors combined do () cause by () per year.
A
- (15) This leads to glacial acceleration and sea-level rise.
- (16) Especially the West Antartic Peninsula is home to breaking shelf ice.
- (17) All of these factors combined do currently cause sea-level rise by 3mm per year.
7
Q
What are the main components of the cryosphere?
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
8 points
A
- Snow
- Permafrost
- Active Layer
- Sea Ice
- Ice Cap
- Glacial Ice
- Ice Shelf
- Iceberg
8
Q
Polar Climate P1/2
- (1) Characterized by () due to factors like (), the (), (), & () from () & ().
- (2) These regions experience () & (), with () typically () annually, classifying them as ().
- (3) The () is largely () or in the form of (),
A
- (1) Characterized by Cold temps. due to factors like latitude, the Earth’s tilt, atmospheric paths, & high reflectance from snow & ice.
- (2) These regions experience polar high pressure & dry Arctic air, with rainfall typically less than 250mm annually, classifying them as deserts.
- (3) The available water is largely frozen or in the form of sea ice.
9
Q
Polar Climate P2/2
- (4) Though some () from currents like the ()/() and ()/().
- (5) Summers are () but feature (), with the warmest month potentially reaching up to ().
A
- (4) Though some polar maritime air from currents like the Japanese Current/Bering Current and Gulf Stream/Labrador Current.
- (5) Summers are brief but feature strong radiation, with the warmest month potentially reaching up to 10°C.
10
Q
Polar Soils P1/2
- (1) Polar soils, known as (), are characterized by (), which are found within () of the ().
- (2) These soils experience (), creating () that thaws & refreezes each year.
A
- (1) Polar Soils, known as Gelisols, are characterized by permanently frozen layers of Permafrost, which are found within 100cm of the soil surface.
- (2) These soils experience a seasonal melt, creating an active layer that thaws & refreezes each year.
11
Q
Polar Soils P2/2:
- (3) These soils cover ~ (), primarily in regions like (), (), () and ().
- (4) These soils often show signs of () and/or () in the (), which is the ().
A
- (3) These soils cover ~11 Ma km2, primarily in regions like USA (Alaska), Canada, Russia and Lesotho.
- (4) These soils often show signs of cryoturbation and/or ice segregation in the active layer, which is the seasonal thaw layer.
12
Q
Permafrost: A Carbon Source
- Permafrost is () deep
- Permafrost contains about ()
- Very () for a mineral soil
- Potential () also.
A
- Permafrost is 20-40m deep
- Permafrost contains about 500 Gt of C
- Very high carbon concentration for a mineral soil
- Potential methane gas release also
13
Q
Local Impact of Permaforst disturbance
- Disturbances, such as (), lead to () in the ().
- () results in (), (), () & ().
- These disturbances are often a result of (), (), but also ().
A
- Disturbances, such as the removal of insulation, lead to increases in the active layer.
- Permafrost melt results in Thermal Degradation, Subsidence, Melt Ponds & Thermokast formation.
- These disturbances are often a result of construction, fire, but also climate change.
14
Q
Sea Ice definition
A
Ice which forms @ the sea surface when water temp. falls below 0ºC
15
Q
Sea Ice P1/2
- (1) Sea Ice thickness is ().
- (2) The () thickness is () when () is () by ().
- (3) Its called () when floating freely with wind and currents.
- (4) () does not cause ().
- (5) But () changes ().
A
- (1) Sea Ice thickness is variable
- (2) The equilibrium thickness is 3m when surface melting is equalled by bottom freezing.
- (3) Its called Pack Ice when floating freely with wind & currents.
- (4) Melting does not cause sea-level rise
- (5) But Melting changes earth’s albedo.
16
Q
Sea Ice P2/2
- (6) Less () and () in Summer:→ Less ()→ More ()→ More ()→ () Ocean, Less () and ()→ () Feedback….. Not Good
A
- (6) Less Sea Ice and Snow in Summer:→ Less Reflectance→ More Heat Absorption By Water→ More Heating of Arctic Ocean→ Warmer Ocean, Less Ice and Snow→ Positive Feedback….. Not Good
17
Q
Ice Shelf Definition
A
Floating sheet of ice attached to the coast
18
Q
Ice Shelf
- Nourished by () and () from the ().
- Ice shelf may move by as much as () per year.
- () can be up to () tall.
- Shelf () is () and producing () when ice shelf is ().
- () of Antarctic coast is covered by ice shelves.
- The () Ice Shelf is () deep and () across.
- () → contact between () and ().
A
- Nourished by Snow fall and Glacial inputs from the land
- Ice shelf may move by as much as 1-3km per year.
- Seaward edge can be up to 60m tall.
- Shelf top is flat and producing tabular icebergs when ice shelf is calving
- 30% of Antartic coast is covered by ice shelves.
- The Ross Ice Shelf is 900km deep and 800km across.
- Grounding Line → contact between shelf and bottom
19
Q
Glacial Acceleration after Shelf Loss P1/6
The 4 Stages:
(1)
(2)
(3)
(4)
A
- Stable Glacier & Ice Shelf
- 2 Effects of Warmer Temps.
- Unstable Glacier Front After Ice Shelf Collapse
- Glacier Acceleration
20
Q
Glacial Acceleration after Shelf Loss P2/6
(1) Stable Glacier & Ice Shelf:
* Point:
* Point:
* Point:
A
- Glacier flow is driven by gravity (glacier moves downhill under own weight)
- Ice shelf is supported by a combination of buoyant (hydrostatic) forces @ ice shelf front, which helps keep the shelf in place, particularly @ the grounding line (where the ice meets the ocean floor).
- This buoyant force partially supports the ice shelf’s mass.
21
Q
Glacial Acceleration after Shelf Loss P3/6
(2) 2 Effects of Warmer Temps:
- Point 1:
(2) - Point 2:
(2)
A
-
Meltwater Infiltration:
1. As temp rises, meltwater forms on glacier surface & percolates down thru. glacier, speeding up the glacier’s flow.
- Typically occurs only in summer
-
Water-filled fractures:
1. Warmer temps can cause fractures in ice shelf which water fills, further weakening & destabilizing ice.
- Filled fractures carve thru. ice shelf -> shelf disintergration
22
Q
Glacial Acceleration after Shelf Loss P4/6
(3) Unstable Glacier Front After Ice Shelf Collapse:
- Point:
- Point:
- Point:
A
- Once ice shelf collapses & retreats past grounding line -> buoyant support that helped stabilize the ice shelf is lost.
- Even though support decreases, glacier flow continues, & glacier front starts to calve -> rapid loss of icebergs.
- Glacier becomes more unstable after this collapse
23
Q
Glacial Acceleration after Shelf Loss P5/6
(4) Glacier Acceleration:
- Point:
- Point:
- Point:
- Point:
A
- Ice shelf loss -> glacier acceleration
- Lower part of glacier steepens & speeds up -> increases ice flow to ocean.
- As glacier accelerates, begins to lose mass more quickly -> more rapid iceberg calving.
- Glacier’s surface also changes from its old, stable position to a new, steeper surface, which increases overall movement.
24
Q
Glacial Acceleration after Shelf Loss P6/6
Implications:
(1)
(2)
A
(1) Leads to a feedback loop
(2) This process contributes significantly to sea level rise as more ice flows into the ocean.
25
Q
Northern Vs Southern Polar Regions P1
- (1) Names
- (2) Hemisphere
- (3) Geography
- (4) Size
- (5) Snow
A
- (1) (N) Arctic & (S) Antarctic
- (2) Arctic (Northern H) & Antarctic (Southern H)
- (3) Arctic (an Ocean covered by a thin layer of perennial sea ice & surrounded by land/continents) VS Antarctic (a Continent covered by a very thick ice cap and surrounded by a rim of sea ice & an Ocean)
- (4) Arctic is slightly larger than the Antarctic
- (5) Both have significant snowfall but Arctic (snow on sea ice w. more seasonal melting) vs Antarctic (snow on vast, stable ice sheet on land w. min. seasonal melting).
26
Q
Northern vs Southern Polar Regions P2
- (6) Mountain Ice
- (7) Ice caps
A
- (6) Forms on high ground & ice caps for both BUT Arctic (significant seasonal melting) & Antarctic (v. little melting)
- (7)
Arctic:
Greenland:
→ smaller in size & volume than Antartica,
→ surface water in summer,
→ lakes & rivers present,
→ more significant negative mass balance
&
Antarctic:
Antarctica:
→ larger in size & volume than Arctic,
→ no surface water even in summer,
→ negative mass balance but more warming in West Antartica than East
27
Q
Northern vs Southern Polar Regions P3
- (8) Glaciers
A
Arctic:
→ Primarily land-based but has sea-ice too,
→ smaller & less thick than Antarctic’s,
→ more seasonal melting,
→ more prone to retreat)
&
Antarctic:
→ Primarily land-based & part of Antarctica Ice Sheet,
→ larger & thicker,
→ less prone to seasonal melting & retreat
→ BUT West Antarctica & Peninsula show increasing melting/retreat.
28
Q
Northern vs Southern Polar Regions P4
- (9) Shelf Ice
- (10) Sea Ice
- (11) Permafrost
A
- (9) Very little shelf ice in Arctic vs Antarctica (Sudden break up noted in recent years since Larsen B as well as other areas)
- (10) Arctic:
→ 16 Ma km2 max. in Winter,
→summer min. dropping &
→melt seasons getting longer
&
Antarctic:
→ (20 Ma km2 max. in Winter,
→ slight increase in sea ice cover
(11) Arctic:
→ Most of world’s permafrost in the NH.
→ Active layer is natural but also disturbed by direct human impact.
&
Antarctic:
→ Very little permafrost in SH
29
Q
Northern vs Southern Polar Regions P5/5
- (12) Similarities
A
- Both contributing to sea-level rise thru. melting of land-based ice
- Recent Ice Loss Acceleration
- Feedback Mechanisms (albedo - Arctic & ice shelf collapse - Antarctic) that exacerbate ice loss.
30
Q
Why is Antartica so cold?
- Point 1
- Point 2
- Point 3
- Point 4
- Point 5
A
- Antarctica is a continent surrounded by an ocean = interior areas don’t benefit from the moderating influence of water
- With 98% of its area covered with snow and ice, it reflects most of the sun’s light rather than absorbing it.
- The extreme dryness of the air causes any heat that is radiated back into the atmosphere to be lost instead of being absorbed by the water vapor in the atmosphere.
- During the winter, the size of Antarctica doubles as the surrounding sea water freezes, effectively blocking heat transfer from the warmer surrounding ocean.
- Has a higher average elevation than any other continent on Earth which results in even colder temperatures.
31
Q
What are the causes of sea-level rise?
(1)
(2)
(3)
(4)
(5)
(6)
A
(1) Glaciers melting & their increased movement & calving causes sea level rise
(2) Mountain ice melting (seasonal melting)
(3) Ice Shelf Collapse -> increase glacier movement -> ice flow to ocean -> SLR
(4) Loss of Sea Ice -> reduces surface albedo & causes ocean to become warmer -> indirect sea level rise
(5) Permafrost melting -> increase in greenhouse gas emissions -> warmer temps -> melting & sea level rise
(6) Thermal Expansion -> as ocean water warms -> expands -> SLR
