Unit 2 Quiz

Prime Meridian

(0 degrees longitude) an imaginary line that runs through Greenwich England and separates the Eastern and Western Hemisphere

Oblate Spheroid

(shape of the earth) bulges very slightly at the equator and flattens very slightly at the poles

How does latitude work?

- (x axis) lines that RUN east and west BUT MEASURE north and south - 0 to 90 degrees north/south -equator divides Northern and Southern Hemisphere -largest great circle of latitude -Earth rotates COUNTERCLOCKWISE (west to east) so sun rises in the east and sets in the west

What is longitude?

- (y-axis) lines that RUN north and south BUT MEASURE degrees east and west of the Prime Meridian

What is the shape of the earth?

-NEARLY a perfect sphere -oblate spheroid

How do we prove the earth is round? -Satellite pictures

-Satellite pictures are the best piece of evidence we have to prove Earth's shape

1 degree latitude/longitude=

-approximately 70 miles -60' minutes

Time zones

-each time zone is 15 degrees apart -Earth rotates 360 degrees in 24 hours (360 degrees/24 hours= 15 degrees/hour) -all places on the same longitude have the same solar noon (sun is highest in the sky)

What proof is there that the earth is slightly oblate?

-gravity measurements. gravity is the force of attraction between any 2 objects. increase mass of objects=increase gravity decrease distances=increase gravity -if Earth were a perfect sphere, it would be expected to exert an equal force on objects at equal distances from the center of Earth

What is a Meridian?

-lines of longitude that separate time zones -they converge (come together) at the poles and diverge (separate) at the equator

How do we describe the Earths surface?

-mostly smooth -even largest mountains are very small compared to the earth

How do we prove the earth is round?-Lunar eclipse

-only a sphere can cast a shadow that appears round. during a Lunar eclipse the Earth casts its shadow on the moon during the full moon phase

Same latitude

-same # of day light hours -similar seasons -same angle of insolation (sun) -same sunrise and sunset

Oblate sphere

-the difference is SMALL -we CAN NOT see it with the naked eye -earth still appears like a sphere -BE CAREFUL ON A MULTIPLE CHOICE ALWAYS PICK THE PERFECT SPHERE

How do we prove the earth is round?-Altitude of Polaris

-this is the star that lies in space directly over the geographic North Pole of the Earth -if you stood at the North Pole, Polaris would be directly overhead -Polaris=to latitude (in Northern Hemisphere) -increase latitude, increase the altitude of Polaris

How can we calculate how round the Earth is?

-use roundness ratio -a perfect sphere had a roundness ratio to 1 -rr= polar diameter/equatorial diameter -example) Earth rr= 12,714 km/12,756km

Weight—-> Meausre of gravitational force

-we are further from the from the center of the Earth at the equator- gravity is less -this means we weigh less -we are closer to the the poles so we weigh more

What is the roundness ratio of a perfect sphere?

1

How do we prove the earth is round?

1) Satellite pictures 2) Sinks ship 3) Lunar eclipse 4) Altitude of Polaris 5) Gravity

Earths polar diameter

12,714 km

Earths equatorial diameter

12,756 km

What is the highest degree of longitude?

180 degrees - range 0 to 180 W/E

What is the international date line?

180 degrees longitude -separates one day from the next -longitude lines are separated 15 degrees apart

What is the highest degree of latitude?

90 degrees - range is 0 (doesn't have N/S) to 90

lines of latitude

ARE PARALLEL

What are the layers of the Earth? Outer core

Believed to be liquid iron- because seismic (S or earthquake) waves can't pass through. responsible for magnetism of Earth

What are the layers of the earth? -Crust

Continental crust (thick and less dense) Oceanic crust (thinner and more dense) -30% of earths surface

What is longitude and latitude?

Imaginary lines on a map used as earth's coordinate system

As latitude increases, what happens to the altitude of Polaris?

It increases

Troposphere

Mostly nitrogen gas (78%) and oxygen gas (21%). some water vapor

What are the layers of the earth?- Hydrosphere

Oceans, lakes, rivers, etc. -70% of earths surface

Stratosphere

Ozone (03)- protects us from UV radiation

Object that best represents a true scale model of the shape of earth

Ping pong ball

Plastic mantle or asthenosphere

Putty like properties. Hot rocks that can flow (convection currents)

Why do Meridian lines zig zag over populated areas?

So populated areas aren't separated by two different time zones

What are the layers of the Earth?-Inner core

Solid iron and nickel Most pressure and density Meteor evidence

Stiffer mantle

Solid rock

What are the layers of the earth? -Atmosphere

Sub divisons: -Thermosphere -Metosphere -Stratosphere -Troposphere -Temp begins to change at each "pause" when altitude increases= pressure decreases and density decreases

What are the layers of the Earth? -Mantle

Sub divisons: -rigid mantle -plastic mantle or asthenosphere -stiffer mantle -crust and rigid mantle combine to form the lithosphere-brittle outer shell of rock surrounding Earth

Why do the stars around Polaris appear to move?

The Earth rotates on its axis

What causes oblateness?

The earths rotation

What best explains the apparent sinking of sailboats?

The sailboat is moving around the curves surface of the Earth

What is evidence that the Earth rotates on it's axis?

The stars appear to follow daily circular paths around Polaris

Rigid mantle

Very similar to oceanic crust

Solar noon occurs

When the sun is at its highest altitude

The angle of the star Polaris above the northern horizon can be used to determine an observers

latitude

Compared to the weight of a person at the North Pole, the weight of the same person at the Equator would be

slightly less, because the person is farther from the center of Earth

Zenith

the highest point in the sky (90 degrees north)