Earth Dimensions

The Structure of Earth

1. The Lithosphere: The rock near Earth’s surface, which is covered by a layer of soil or loose rock.

Lithosphere Thickness: Varies from about 70 to 150 km

Lithosphere b. Composition: Oxygen and Silicon are the two most abundant elements by mass.

Lithosphere c. Density: Approximately 2.7 – 3.0 g/cm3

2. Hydrosphere: The liquid layer of the Earth

Hydrosphere Approximately 71% of the Earth’s surface is covered by water a. Thickness: The oceans extend to an average depth of 3.5 to 4 km

Hydrosphere b. Composition: Hydrogen and Oxygen

Hydrosphere c. Density: 1 g/cm3

3. Atmosphere: The shell of gas surrounding the earth

Atmosphere The atmosphere is divided into 4 distinct layers based on temperature. 1) Troposphere 2) Stratosphere 3) Mesosphere 4) Thermosphere

Atmosphere a. Thickness: The atmosphere extends several hundred km into space.

Atmosphere b. Composition: Composed primarily of nitrogen (78%) and oxygen (21%).

Atmosphere c. Density: Extremely low.

The Shape of the Earth The Earth appears to be a perfect sphere.

Actual Shape of Earth Earth Measurements Diameter(km) Circumference(km) Polar 12,714 40,008 Equatorial 12,756 40,076

Actual Shape of Earth Earth is actually an Oblate Spheroid, slightly flattened at the poles and bulging a little at the equator

Evidence of Earth’s Round Shape Pictures of Earth

Ships appear to sink

Changing positions of the sun and stars

Locating Positions on Earth 1. Coordinate Systems: A system of lines forming a grid on the earth’s surface; a pair of coordinates (latitude & longitude) is used to locate positions on earth.

On the map horizontal lines are lines of latitude and.... vertical lines are lines of longitude. The X axis is the equator and the Y axis which runs through Greenwich, England is the Prime Meridian. Equator Prime Meridian

Any location north of the equator is a NORTH LATITUDE

Any location south of the equator is a SOUTH LATITUDE

Any location west of the prime meridian is a WEST LONGITUDE

Any location east of the prime meridian is an EAST LONGITUDE

We can divide the Earth into quadrants: NE where all latitudes are NORTH and all longitudes are EAST.

We can divide the Earth into quadrants: SE where all latitudes are SOUTH and all longitudes are EAST.

We can divide the Earth into quadrants: SW where all latitudes are SOUTH and all longitudes are WEST.

We can divide the Earth into quadrants: NW where all latitudes are NORTH and all longitudes are WEST. Notice that EVERY point in the United States will have a NORTH latitude and a WEST longitude since we are in the NW quadrant.

Latitude and Longitude of NYS

III. Measuring Latitude(parallels) Angular distance in degrees north or south of the equator. 0o

Polaris: Also called the North star. Any location North of the equator has a latitude equal to the angle of Polaris above the horizon. Polaris Location X: latitude = 50o 40o to horizon X

Polaris 43o North East Joe Cool's latitude = 43oNorth

IV. Measuring Longitude (meridians) Angular distance in degrees east or west of the Prime Meridian. 0o

Longitude Lines of longitude begin at the Prime Meridian. 60° E is the 60° line of longitude east of the Prime Meridian. 60° W is the 60° line of longitude west of the Prime Meridian. The Prime Meridian is located at 0°. It is neither east or west W E TEKS: Social Studies – 6.22 (A), Using social studies terminology correctly 7.22 (A), 8.31 (A)

Longitude 180° N North Pole W E West Longitude East Longitude PRIME MERIDIAN S Lines of longitude are numbered east from the Prime Meridian to the 180° line and west from the Prime Meridian to the 180° line. TEKS: Social Studies – 6.22 (A), Using social studies terminology correctly 7.22 (A), 8.31 (A)

Earth rotates west to east Solar time is based on the position of the sun NIGHT IS FALLING ON EARTH Look at the East Coast of the United States. The lights are already lit. California the sun is still visible.

This pictures shows AMERICAN CITIES at night.

It’s still daylight in California Saguenay Sept-Iles Thunder Bay Toronto St.John Ottawa It’s still daylight in California Québec Montréal Those light are Boston, New York, Philadelphia and Washington. Detroit Dallas Puerto Rico Houston Miami Mexico City Havana Port-au-Prince

The earth rotates 360o in 24 hours one day at a rate of….. There 24 time zones around the world because of Earth’s rate of rotation. What is Earth’s rate of rotation? The earth rotates 360o in 24 hours one day at a rate of….. .

If it is 9pm on the 45oE longitude line, Time Zones- For every 15o of longitude traveled, time increases by 1 hour traveling eastward, and decreases by 1 hour traveling westward. If it is 9pm on the 45oE longitude line, what time is it on the 15oW longitude line? 5 pm West East 45o 30o 15o 0o 15o 30o 45o

Time is forward to all places to the east WEST LESS ANOTHER CHEESY SAYING EAST INCREASE Time is forward to all places to the east WEST LESS Time is backward to all places to the west

East Increase – West Less (1 hr per l5°) If it 9 p.m. at Position D, what time is it at position C? Position B? If it is 1 p.m. at Position X, at which location is the time 5 p.m.

V. Fields A field is a region of space in which a similar quantity can be measured at every point or location.

Isolines Lines that connect points of equal value on a field map.

Isotherms

Isobars

Contour Lines

VII. Topographic Maps (Contour Maps) Shows the shape of Earth’s surface using contour lines to indicate the elevation above sea level.

What is the contour Interval?

What is the contour interval?

stream flow direction- When contour lines cross streams, the lines bend, making a “V” that points upstream, the stream flows in the opposite direction. What direction is the stream flowing? Southwest

Depression Contours - Depression Contours indicate a depression in the land. Hachure marks are drawn on contour lines and point towards the center of the depression.

The first depression contour line has the same value as the lowest ordinary contour line next to it.

Values between lines: What values exist between the 700 foot contour line and the 720 foot contour line?

N X When contour lines are close to each other, the slope of the land is steep Place an X to show the steeper side.

d. definition of gradient- average slope of the land. Gradient =

Mrs. Stein just climbed Mt Kilamanjaro. Pretty intense Mrs. Stein just climbed Mt Kilamanjaro. Pretty intense! She started her journey at 5,000 feet. The summit of Kilamanjaro is 19,000 feet. The trail was 10 miles long. Calculate the gradient of her journey! Use ESA

Calculate the gradient between points x and y:

profiles: A cross sectional view; a vertical slice of land.

Finding the Distance Between Two Points in New York State

Question: What is the distance, in miles between Ithaca and Watertown, NY? First, open your Earth Science Reference Tables to page 3, the Generalized Bedrock Geology Map......................

Find the two cities, Ithaca and Watertown (red dots)

Using an index card or blank piece of paper, line up one edge between the two cities. Be accurate!

Make a small, straight mark on the card at the location of each city (red lines).

Move the card to the key. Be sure to use the “miles” side since that’s what the question is asking for. Place one of the red marks on the 0.

With one of your red marks at the 0, make a mark at the end of the key at 50 miles (see blue line).

Now slide the card along until the blue mark is at 0 Now slide the card along until the blue mark is at 0. Make a note that the distance between your first red mark and the blue mark is 50 miles.

Make another mark at the end of the key (second blue mark) and note that the distance between the two blue marks is another 50 miles.

Slide the card over until the second blue mark is on the 0 Slide the card over until the second blue mark is on the 0. Note that the distance between the blue mark and your second red mark is another 10 miles.

Now just add up the miles. Ithaca is 110 miles from Watertown.

Things to remember....................... 1) Read the question carefully. Be sure you know whether you’re measuring miles or kilometers. 2) When making the marks at the cities or mountains be sure your line is on the dot representing that city or the triangle representing the mountain. 3) Be accurate. Make small straight marks and keep track of distances measured at the key. 4) Don’t be lazy. Go back and check your work!