Mapping Longitude and Latitude

Transcription

1 Title: Mapping Longitude and Latitude (Latitude & Longitude) Grade Level(s): 6 Introduction: Using the equator and prime meridian, map makers have constructed a grid made up of lines of latitude and longitude to find locations anywhere on Earth. The latitude is the distance in degrees north or south of the equator. All lines of latitude are parallel to the equator. The distance in degrees east or west of the prime meridian is called longitude. There are 360 lines of longitude that run from north to south, meeting at the poles. Each line represents one degree of longitude. Lines of latitude and longitude were used to draw the boundaries between many states. Map makers also use map projections to show the Earth s curved surface on a flat map. A map projection is a framework of lines that helps to show landmasses on a flat surface. Learner Objectives: The students will explain how maps and globes represent Earth s surface and state what a map projection is. The students will be able to identify the equator and prime meridian and state how latitude and longitude are used to locate points on Earth s surface. Florida Sunshine State Standards: Competency Based Curriculum: Science: SC.H.3.3.6, Math: MA.E Math: M/J-I-V-2-A/M/J-3-VI-2-A; Science: M/J-3-I-1-B Materials: United States map with latitude, longitude, and state borders Tracing paper Paper clips Colored pencils I-A-11

2 Activity Procedures: 1. Lay a sheet of tracing paper on top of a map of the United States. 2. Trace over the Pacific and Atlantic coasts of the United States with a blue pencil. 3. Using the blue pencil, trace all Great Lakes shorelines that reach nearby states. 4. Trace all state borders that go exactly north-south with a red pencil. 5. Use a green pencil to trace all state borders or sections of state borders that go exactly east-west. 6. Use a blue pencil to trace the borders that follow rivers. 7. Use a brown pencil to trace any borders that are not straight lines or rivers. Student Assessment: 1. Allow students to answer critical thinking questions assigned by teacher. a. Compare and contrast the various means of calculating latitude and longitude during ancient times. b. The sun and the stars can be used to calculate the latitude north or south of the equator but not the easterly or westerly position that is, the longitude. Explain why. 2. Allow students to use an atlas to describe a city in terms of its latitude and longitude. Activity Extensions: 1. Encourage students to research the relationship between mapmaking and technological innovations (Science/Technology Integration). 2. Encourage students from diverse parts of the world to use a world map to determine the latitude and longitude of the capitals of the countries where they or their parents originated (Social Studies/Language Arts). 3. Allow students to research the history of Florida to find out when and how its borders were established (i.e., Latitude and Longitude, Landforms, etc.). I-A-12

3 Home Learning Activity: Assign a city to each student and challenge them to use a map to describe everything they can about that city, including latitude and longitude and the hemispheres it is in. Ask students to identify a point in a selected ocean and pretend that they are a ship lost at sea. Have the students determine the degrees of longitude and latitude so that they may call for assistance. Vocabulary: equator, prime meridian, longitude, latitude References/Related Links: www1.minn.net/~keithp/loni.htm Glencoe (2000). Science Voyages, Westerville, OH: Glencoe/McGraw Hill. I-A-13

4 Mapping Longitude and Latitude Reading Passage Imagine yourself standing at night at point P on Earth and observing the pole star (or better, the position of the north celestial pole, near the star), at an elevation angle h above the horizon. The angle between the direction of the pole and the zenith is then (90 degrees - h). Therefore h is also your latitude. In the age of the great navigators of Columbus, Magellan, Drake, Frobisher, Bering and others finding your latitude was the easy part. Captains knew how to use noontime Sun, and before the sextant was invented, a less precise instrument as the cross-staff was widely used. Longitude was a much harder nut to crack. In principle, all one needs is an accurate clock, set to Greenwich time. When the Sun passes the meridian at noon, we only need to check the clock: if Greenwich time is 3 p.m., we know that 3 hours ago it was noon at Greenwich and we are therefore at longitude 15 degrees x 3 = 45 degrees west. However, accurate clocks require a fairly sophisticated technology. Pendulum clocks can keep time quite accurately on firm land, but the pitching and rolling of a ship makes them quite unsuitable for sea duty. In the 17th and 18th century, when the navies of Britain, Spain, France and Holland all tried to dominate the seas, the problem of longitude assumed great strategic importance and occupied some of the best scientific minds. In 1714 Britain announced a prize of 20,000 pounds a huge sum in those days for a reliable solution, and John Harrison, a British clockmaker, spent decades trying to achieve it. His first two chronometers, of 1735 and 1739, though accurate, were bulky and delicate pieces of machinery. Only his 14th instrument, tested in 1761, proved satisfactory, and it took some additional years before he received his prize. I-A-14

5 Mapping Longitude and Latitude FCAT Questions Directions: Read the passage, then answer all the questions below. Answer multiple-choice questions by circling the letter of the answer that you select. Write your answer to the Read, Think, and Explain question on the lines provided. 1. Hydrography is defined as which of the following? A. Study of water pressure B. Study of water properties C. Study of water chemical reactions D. Study of oceans, lakes and rivers Answer: D 2. Which of the following instruments is used to measure latitude? A. Astrolabe B. Chronometer C. Sextant D. Compass Answer: C 3. The distance in degrees east or west of the prime meridian is called: A. Latitude B. Longitude C. Equator D. Point of departure Answer: B 4. How do map makers find distances anywhere on Earth? I-A-15