Lec4: Intro to Geography Flashcards
Distinguish between the Antarctic and Arctic.
Antarctic = Continent surrounded by Southern Ocean Arctic = Ocean surrounded by continents
Describe the equator relative to the Earth’s axis of rotation.
Intersection is perpendicular to the Earth’s axis of rotation.
What significant city does the Prime Meridian intersect?
Greenwich, London
Which hemispheres do the Prime Meridian and Equator separate respectively?
- E/W
2. N/S
What is the Antarctic circle?
A line of latitude at 66 degrees South.
Is the Antarctic circle stationary?
No, it’s shifting.
Which point in Antarctica is there a day of complete sunlight and a day of complete darkness?
On the Antarctic Circle.
What causes the day of complete darkness and light each in Antartica, and in which solstice does each occur?
The earth has an ECLIPTIC ORBIT: Earth is tilted relative to its plane of orbit around the sun
- Winter Solstice = max tilt away = darkness
- Summer Solstice = max tilt towards = light
What is another name for the Antarctic Convergence?
Polar Front.
What two ocean waters meet at the Antarctic Convergence, and what happens to the water southward flowing water temperature here?
Northward flowing cold Antarctic Surface water meets southward flowing warm Subantarctic Surface water, resulting in a 2-3 degrees celsius fall in temperature.
What causes the formation of Antarctic intermediate water?
The saltier and denser AASW sinks below lighter SASW, and mix.
What are the two circum-polar currents around the Antarctic continent, and for each, give:
- Alternate names
- Wind that drives it
- Direction of flow
- Antarctic Coastal/Counter current (East Wind Drift) - Strong easterlies drive it Westwards
- Antarctic Circumpolar Current (West Wind Drift) - strong westerlies drive it east (CLOCKWISE)
What does the Coriolis force do to the flow of the West Wind Drift?
Causes it to deflect northwards and spill into the northward-flowing AASW.
Name the three Antarctic Zones, and state the location and lifeforms.
- Subantarctic Zone: Islands near Antarctic Convergence - Large invertebrates and all major plants (except Gymnosperms)
- Maritime Zone: West Coast of Antarctic Peninsula - Limit for Tracheophytes (vascular plants), but small vertebrates (mites and springtails) found
- Continental zone: Entire continent and ice shelves, except WC of AP - No land-based vertebrates, only mosses, lichen, mites, sprintails near the COAST
How long is the Transantarctic Mountain and what boundary does it mark?
3500km, separating East from West Antarctica
West Antartica:
- Surface area?
- Mostly above or below sea level?
- Structure beneath ice?
- 2.5 mil km2
- Below
- Archipelago
East Antarctica:
- Surface area?
- Mostly above or below sea level?
- Structure beneath ice?
- 10.5 mil km2
- Above
- Single, thick block
What are the two largest embayments, and the five other ones?
- Ross and Weddell Sea
2. Amundsen and Bellinghausen seas, and Pritz Bay
What is the largest ice shelf, and the four main others?
- Ross
2. Ronne, Filchner, Amery, Larsen
How many nations have Antarctic bases?
About 30.
What is the highest peak?
Mt. Vinson
Where is the highest recorded wind speed?
Dumont D’urville Base
Where is the coldest recorded temperature?
Vostok Station
What happens to the size of the continent in winter due to sea ice, and what is the area of sea ice?
Doubles, due to additional 19 mil km2 of sea ice.
What are the six Antarctic Poles?
- South Geographic Pole
- South Pole of Rotation
- South Magnetic Pole
- South Geomagnetic Pole
- Pole of Inaccessibility
- Ceremonial South Pole
What is the difference between South Geographic Pole and South Pole of Rotation?
SGP = Geographical axis of rotation intersects Earth's surface SPOR = Actual axis of rotation intersects Earth's surface, but has a wobbly course so the estimate is used
What is the South Magnetic Pole and where is it currently located?
Where the Earth’s magnetic field is vertical.
On the move, and currently outside the Antarctic circle.
What is the Pole of Inaccessibility?
Furthest mean distance away from the ocean on the continent.
What marks the Ceremonial South Pole, and what surrounds this marking?
A barbers pole with a metallic sphere on a plinth, surrounded by national flags of signatories of Antarctic Treaty.
The South Geographical Pole is marked by a stake. How much must it be moved each year and why?
Moved 10m each year to accomodate downhill-sliding ice sheet.
What is the South Geomagnetic Pole and where is it located currently?
Where a tilted dipole axis intersects the Earth’s surface. On the move, and currently near Vostok Station.
