Alaska - Periglacial Flashcards
1
Q
Alaska
A
- Aprox 63° north of equator
- North west of America
- Borders Canada to east
- Part of pacific ring of fire
2
Q
History
A
- Interest in WW2
- Alaskan highway, carry heavy weapons, threat of Japanese invasion
- USSR + cold war increased significance
- Military infrastructure 25% pop were military
3
Q
Global warming
A
- Active layer deepening / widening
- Surface permafrost temp risen by 1.5°
- Release of co2 trapped in ice
- Positive feedback: More green house gas = more melting, more green house gas
- Longer worm periods
- Shrinking permafrost
- Urban heat island, area 2.2° warmer
4
Q
Exploitation
A
- Gold rush
- Fishing using big nets, damages ecosystem
- Mining produces solid waste water, some facilities not equipped to dispose, dumped in wild
- Housing: heat / tilting due to water logged hollows
5
Q
Oil
A
- First discovered in Prudhoe bay 1968
- Largest oil field in N America
- Exploited for 30 years, 20% of USA oil requirements
6
Q
Damage to ecosystems
A
- Exxton Valdez oil tanker, 1989, spilled 40m litres of oil of coast
- 250000 birds and fish killed
- 30 to 40 oil spills, 1977 - 1994
7
Q
Trans Alaskan pipeline (TAP)
A
- Could not be buried due to melting permafrost (elevated)
- Earthquakes + other hazards
- Can shift sideways
- Zig Zag to expand and contract
- Refrigeration units to keep ground frozen
- Demand ment that it was important to build
- 3 year design, 5 year build
- $8b
- Max output of 1.4m barrels
- 65° oil
8
Q
Protection
A
- 1964 Wilderness Act in several areas
- Denali national park in 1917, extended 1980, banned vehicles, people travel in approved buses + routes
9
Q
Future developments
A
- Oil sites declining, more sites to be discovered
- Can be used for gas and oil in emergencies
- Used by indigenous tribes for food, clothing, shelter
- Used for migration routes for herds