Unit 1 Measuring the Earth In this unit you will learn about the size, shape and features of the earth. You will also learn how to read maps, from the simple to the complex.

A. Models – things that help explain events 1. ___________- uses observations of sight to provide us with explanations example:   2. ____________- models used to simulate natural events 3. _____________- images of something in your mind that you are trying to understand Physical globe Laboratory Stream table Mental

A. Models – things that help explain events 4. _____________- formulas and equations that explain certain properties of a material or system   5. ______________- uses graphs to simplify certain relationships Mathematical Graphic

B. Spherical Earth – evidence to prove it. Mast 1. The of a ship was the first part to appear over the horizon and the last part to disappear.   2. Change in the altitude of the North Star (Polaris) and other celestial objects when you travel north or south. The altitude of Polaris equals the latitude!

Polaris Only star in the night sky that does not move, because Earth’s axis points directly at it Also called the “north star” or the “pole star” Very last star in the handle of the Little Dipper Can only be seen in the Northern Hemisphere Altitude = Latitude of Observer Can be found using the Big Dipper

B. Spherical Earth – evidence to prove it. 3. Shadow of Earth during a lunar eclipse is always the   4. Not a perfect sphere,( ) an object at the equator will weigh than an object at one of the poles because the Earth has a slight bulge at the equator. 5. Space photos. arc (part) of a circle. Oblate Spheroid slightly less

C. Earth’s Dimensions Circumference at Equator Circumference at Poles Diameter at Equator Diameter at Poles Land % of surface Water % of surface 40,076 km 40,008 km 12,756 km 12,714 km 29 71 FYI – Moving at 55 mph it would take you one month to circle the earth.

E. Earth Structure Liquid layer Made up of solid Nickel and Iron Weather takes place here

E. Earth Structure Crust and top of mantle, solid and rocky Lithosphere- 2. _______________-thin layer of water resting on the lithosphere. -covers about of the Earth’s surface. 3.________________-a relatively thin shell of gases, held to Earth by gravity. Crust and top of mantle, solid and rocky Hydrosphere 70% Atmosphere 78% Nitrogen, 21% Oxygen, 1% mostly Argon, Carbon Dioxide, Helium and Water Vapor

F. Coordinate System - Latitude System of imaginary lines that help determine the location of a point on the Earth’s surface.   1.Latitude -distance in degrees__________________________________. -latitude numbers are followed by an N if they’re north of the equator and an S if they’re south of the equator. -equator -North Pole -South pole -Attica north or south of the equator 0° 90°N 90°S 43.3091°N or 43°18’45”N

F. Coordinate System - Latitude _______________-lines that measure latitude. -they are parallel to the equator (horizontal). -degrees of latitude are about 111.1 kilometers from each other.   _____________-(North Star)- The angle of of Polaris in a given location in the northern hemisphere is equal to the of that location. Parallels Same for all lines of latitude. Polaris altitude latitude Very important- don’t forget!

F. Coordinate System - Longitude -distance in degrees -longitude numbers are followed by an E if they’re east of the Prime Meridian and a W if they’re west of the prime meridian.   -Prime Meridian- line that passes through Greenwich, England and connects the - degrees longitude. east or west of Prime Meridian North and South Poles.

F. Coordinate System - Longitude -____________-imaginary semicircles that connect the poles and measure longitude -the distance between them is greatest at the and they come together at the -180 meridian-line on the opposite side of the Earth as the Prime Meridian. -in the middle of the -______________________-roughly follows the 180 meridian but does go around some land areas. -where the changes. Meridians equator poles Pacific Ocean International Date Line date

F. Coordinate System – Longitude and Time chronometer-very accurate clock that keeps time at the Prime Meridian (Greenwich Mean Time- G.M.T.) and the solar time (time by the sun) at any other meridian.   questions: 1. How many are there degrees in a circle? 2. How many hours are there in a day? 3. How many degrees would the Earth rotate in one hour? 360° 24 hours 360° = 15°/hr. 24 hours

F. Coordinate System – Longitude and Time facts: 1.In the Western Hemisphere, local time is than Greenwich time. 2.In the Eastern Hemisphere, local time is than Greenwich time.   questions: 1.If it is 12:00 noon where you live and the chronometer reads 5:00 PM Greenwich Time: a. How many hours are the times apart? b. What is your degree longitude? c. Are you in the Eastern or Western Hemisphere? earlier later 5 hours 5 hrs. X 15°/hr. = 75° Western

G. Fields and Field maps ___________- lines connecting points of equal value on a map. __________- lines that join points of equal barometric pressure on a weather map. __________- lines of equal temperature. _________ __-lines joining points of equal elevation. Isolines Isobars Isotherms Contour Lines

G. Fields – Contour Maps 20 feet contour map- (topographic map) - Two dimensional model which shows the of various points on the Earth’s surface. _____________- isolines that connect points of equal elevation above sea level.   _________________- difference in value between two contour lines. What is the contour interval of this map? elevation Contour lines Contour Interval 20 feet

G. Fields – Contour Maps - Depressions depressions- pits, holes, or low areas in the Earth. - shown on contour maps as - first hachure has the ____________value as the _____________contour line near it. -any hachured lines inside the first in elevation by the contour interval. a hachured line. same lowest decrease Elevation of this line is 80 feet Both lines are 100 feet

G. Fields – Contour Maps - Direction Direction- most maps have an arrow to indicate north, if not they are usually oriented with north -latitude and longitude are usually on maps as well. -degrees are divided into 60 minutes and minutes are divided into 60 seconds. What is the latitude and longitude of the center of Jones Swamp? at the top. 41° 43’ 15” N 72° 17’ 45” W

G. Fields – Contour Maps – Map Scale ratios-many maps have ratios printed on them. -An example is 1:10,000 which means every one inch on the map equals This works for any unit. One centimeter equals scale-distance scale -line that shows what length the distances on maps are equal to.   question- What is the distance from the period in Bert Mtn. to the apostrophe in Bob’s Creek? 10,000 real inches. 10,000 cm. Called a graphic scale. 3.5 miles

G. Fields – Contour Maps - Profiles 1. Place a piece of paper along the area where you are drawing the profile. Profile Procedure 2. Place a mark where each line touches the paper and label it with the elevation. 3. Take the strip of paper and place it on the bottom of the graph. 4. Plot the elevations on the graph and connect the points with a line.

G. Fields – Contour Maps - Slope map slope- (gradient) -determined by comparing the rate of change in between two points gradient = elevation Change in field value Distance questions 1. What is the elevation of the period in Bert Mtn.? 2. What is the elevation of the apostrophe in Bob’s Creek? 3. What is the distance between them? 200 ft. 120 ft. 3.5 miles

G. Fields – Contour Maps - Slope 4. What is the gradient? gradient = 200 ft. – 120 ft. 3.5 miles 80 ft. 3.5 miles Gradient = 22.9 ft/mile 5. If the contour lines are close together , what is it like there? 6. If the Contour lines are far apart, what is it like there? Steep Gentle or gradual

G. Fields – Contour Maps – Stream Flow - streams always flow - contour lines always bend when they cross a stream.  questions- 1. Which direction is Bob’s creek flowing? 2. Which direction is Denbrook flowing?   downhill upstream West South

Contour Maps Topographic maps show elevation of the land by using contour lines, and show other natural and man-made features by using symbols. Contour Line: lines connecting points of equal elevation

Rules of Contour Lines Example of an isoline- line of equal value Elevation (ft)- distance above sea level Never touch or cross each other Steep slope- lines are closer together Gentle slope- lines are farther apart

Rules of Contour Lines 6) Law of V’s- lines curve upward when crossing a stream towards the top of the hill source- where the stream flows from

Rules of Contour Lines 7) Concentric Circles – when there are concentric circles on a map, that indicates the top of a hill or mountain.

Rules of Contour Lines 8) Hachure Lines- when you see concentric circles with hachure marks, that indicates a depression on Earth’s surface. The first line with the hachure marks is equal to the contour line with the lowest value next to it.

Rules of Contour Lines 9) Contour Interval- difference in elevation between two consecutive contour lines. -small for flat areas -greater for steep areas

Rules of Contour Lines -bold contour lines -every 5th line is marked in feet Contour Interval= 20 ft.