Antarctica (geography & threats) Flashcards
Outline the location of Antarctica
South of the entire Antarctic circle except some of East Antarctic coastline & Antarctic Peninsula
Outline the ocean Antarctica is located in
Southern Ocean - 60°S latitude and encircling Antarctica with 360° longitude
Define the Antarctic convergence zone
When cold North H2O meet with warm South H2O
32-48km wide
Outline the necessity of the Antarctic convergence zone
Warm H2O sinks under cold H2O causing upwelling currents = marine productivity - Krill
Outline 3 ways how the Antarctic convergence zone a “natural boundary”
Separates:
1. 2 distinct hydrological regions
2. Areas of distinct climates
3. Areas of distinct wildlife
Define the Antarctic Circumpolar current
Created by Antarctic convergence zone - current flowing round antarctica at 60° latitude south
Blocks warmer waters travelling southwards
What composes the majority of Antarctica?
Mountainous & rocky terrain - (97%)
How is Antarctica split?
Unevenly into East Antarctica and West Antarctica by the Transantarctic range (peaks above 4000m)
Outline the elevation of Antarctica
Height over 2300 m above sea level
Highest continent due to ice sheet thickness
Outline the average annual temperature, wind speed and precipitation of Antarctica
Temperature = -49°
Wind speed = 50mph
Precipitation = <50mm
Define nunatak
Isolated peak of rock projecting above a surface of inland ice/snow
Define Dry Valleys
Found in high altitude + extreme aridity
In the Transantarctic Mountain Range forcing air upwards therefore lose moisture
Define Sealing
The culling of seals for meat and/or fur
Outline the effects of sealing in the 18th century to 1800
Within 3 years - 300,000 seals were killed - almost eradicated
Define Whaling
Hunting of whales
Define ambergris
Whale vomit - $50,000 - 70,000
Outline the Norwegian whaling business in 1904
Grytviken - >300 people and sold a range of whale products (e.g meat, bonemeal, etc)
Abandoned 1965 - due to whale stock depletion
Outline the IWC
When was it established and what did it cause?
International Whaling Commission
Established 1946
Ended most whaling 1985
What was the Southern Ocean Whale Sanctuary and when was it made?
An area of 50 mil km^2 surrounding Antarctica where all commercial whaling was banned
Made 1994
What country opposed the Southern Ocean Whale Sanctuary?
Japan - obeyed IWC Charter that allowed whaling for scientific research
What has replaced fishing in the Southern Ocean Whale Sanctuary?
What countries do this?
Fishing - 1960s Russia exploited for many fish species (e.g Antarctic rock cod)
Recently Russia and Japan take many fish
Outline Krill and their importance to Antarctica
Tiny shrimp like crustaceans that underpin thew entire Antarctic food web
Why are Krill hunted?
Rich in omega 3 fatty acids - make Krill oil capsules
Causes overfishing
