Presentation is loading. Please wait.

Presentation is loading. Please wait.

Chapter 3 – Models of the Earth

Similar presentations


Presentation on theme: "Chapter 3 – Models of the Earth"— Presentation transcript:

1 Chapter 3 – Models of the Earth

2 Section 3.1 Finding Locations on Earth
Objectives Distinguish between latitude and longitude. Explain how latitude and longitude can be used to locate places on Earth’s surface. Explain how a magnetic compass can be used to find direction on Earth’s surface.

3 EARTH REFERENCE POINTS
AXIS OF ROTATION NORTH POLE SOUTH POLE EQUATOR NORTHERN HEMISPHERE SOUTHERN HEMISPHERE

4 LATITUDE The angular distance north or south of the equator. This set of circles are called parallels because they run east and west parallel to the equator

5 DEGREES OF LATITUDE Measured and labeled as being north (N) or south (S) of the equator (0°) Degree km (1/360th of Earth’s circumference). Maximum values are at the geographic poles (90°N and 90°S).

6 Minutes and Seconds Degrees can be further subdivided:
Astrolabe – Early Instrument Used To Determine Latitude

7 LATITUDE IN 1300’S

8 LONGITUDE East-west locations established by using meridians, semi-circles that run from pole to pole. Prime Meridian (0°) runs through Greenwich, England. Longitude is the angular distance, measured in degrees, east or west of the prime meridian.

9 Degrees of Longitude The meridian opposite the prime meridian is labeled 180°. All locations east of the prime meridian have longitudes between 0° and 180°E, those west between 0° and 180°W. Can also be subdivided into minutes and seconds.

10 Distance Between Meridians
The only place on the earth where 1° of longitude equals 111 km is at the equator. Why? All meridians (lines of longitude) meet at the poles, so the distance measured by a degree of longitude decreases as you move from the equator toward the poles.

11 LATITUDE & LONGITUDE (We Make A Grid To Tell Location)

12 WHERE ARE WE? (Latitude Comes First, Then Longitude)
Fall City - 47o33'59"N, 121o54'08"W North Bend - 47o29'45"N, 121o47'19"W Snoqualmie - 47o31'27"N, 121o49'03"W

13 a globe it is a straight line.
Great Circles Any circle that divides the globe into halves. Often used in navigation, especially by aircraft. Shortest distance between any two points on a sphere. On a map a GC is curved, on a globe it is a straight line.

14 Finding Direction One way is to use a magnetic compass. This is because of the earth’s magnetosphere.

15 Geomagnetic Poles The earth acts like it had a giant bar magnet inside it. It is tilted relative to the geographic poles. A compass needle points to the geomagnetic pole.

16 Magnetic Declination The angle between a compass reading and true north, measured in degrees east or west of the direction of the geographic North Pole. A compass reading is only accurate along the line of 0° magnetic declination.

17 Polar Wander The geomagnetic pole, over time, changes position. Today it is slightly west of Ellesmere Island (Canada).

18 The Global Positioning System (GPS)
A global network of 24 satellites. Radio signals from 3 satellites allow a GPS receiver to calculate the latitude, longitude, and altitude of the receiver. Accurate to ±15 meters.

19 ASSIGNMENT Outlining Review Section Outline 3:1 3.1 Key Terms
3:1 Directed Reading Worksheet


Download ppt "Chapter 3 – Models of the Earth"

Similar presentations


Ads by Google