Topic 1- The Earth Flashcards
(31 cards)
What is located at 66.5 degrees north
Artic circle
What is located at 23.5 degrees north
Tropic of Cancer
What is located at 0 degrees latitude
Equator
What is located at 23.5 degrees south
Tropic of Capricorn
What is located at 66.5 degrees south
Antarctic circle
What is located 90 degrees north
North Pole
What is 90 degrees south
South pole
What line of longitude is 0 degrees
Prime meridian
What is local glare
Comes from light sources from sports grounds, car parks, street lights and security light etc which ruins dark eye adaptions
What is sky glow
Rusty orange haze casted by lights from near towns an cities which reduces contrast between stars and the sky
Why is the sky blue
Light is scattered by oxygen and nitrogen particles in our atmosphere as blue light scatters more the sky appears blue
Why do stars appear to twinkle
Atmosphere refracts light which means the position and clarity of star viewing is less accurate movements in the atmosphere cause stars to twinkle
What is the shape of the earth
An oblate spheroid
What is the mean diameter of the earth
13000km
What are the internal division from surface to middle
Crust
Mantle
Outer core
Inner core
What does the altitude of the NCP equal
Latitude of observer
What makes up the crust
Solid layer of tectonic plates composed of iron, oxygen, silicon,
How thick is the crust
8-70 km of continental crust over 8km of oceanic crust
What is the temperature of the crust
20 degrees Celsius
How much does the mantle make up of the volume of earth
80 percent
What is the thickness of the mantle
2900 km
What is the temperature of the mantle
1400-3000 degrees Celsius
What is the outer core made of
Liquid nickel and iron
What does the outer core generate
Earth magnetic field current
