Name: Mr. DeLeo Date: Period: Earth s Time Zones Goal: Students will understand why humans have developed time zones on Earth, and how to figure out time at different positions on Earth. Background: One of the first things people noticed when they traveled across Earth s surface was that the positioning of the Sun would change as a person traveled east or west. This caused the time of sunrise, sunset, and solar noon to change as a person traveled east or west. Today, we know this happens because the Earth has a spherical shape, and 12 PM (noon) will only occur at one longitude at one time. For this reason, humans created time zones in order to ensure each location experienced solar noon (sun at its highest point in the sky) at roughly 12 PM (noon). In the United States, we know that if it is 12 PM (noon) in New York (Eastern Standard Time), it is only 9 AM in California (Pacific Standard Time), and various other times around the world. In total, there are 24 time zones, each with a width of 15 degrees, because Earth rotates on its axis 15 degrees per hour. Time Zones In The United States Time Zones On Earth Directions: On the following page is an image provided by Google Earth, showing a top down view of the Earth, with the North Pole at the center. The Prime Meridian is drawn, and as we know has a longitude of 0 degrees. Using a protractor and your knowledge of time zones, accurately create all the time zones around the Earth. Remember, each time zone should be 15 degrees wide, with a total of 24 time zones on Earth. 1
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Questions: Use the maps in your Earth Science Reference Table to answer the following questions. Show all work. 1. The time is 5 PM in New York ( 75 W). What time is it in Greenwich, England (0 )? 2. The time is 3 AM in Alaska (150 W). What time is it in New York (75 W)? 3. The time is 10 PM in Australia (150 E). What time is it in New York (75 W)? 4. If the time in one location is 1 PM, and the time in another location is 9 AM, how many degrees longitude are in between these two locations? 5. If it is 12 PM (noon) in New York, what longitude would be experiencing 12 AM (midnight)? 3
Practice Regents Questions 1. Base your answer to the following question on passage and time zones map shown below. Time Zones In 1883, Earth was divided into 24 time zones. The United States (excluding Alaska and Hawaii) has four time zones, which are indicated by different shadings on the map.each zone is roughly centered on lines of longitude that are 15 apart. These lines are shown as dashed lines on the map. Most locations within a time zone have the same time.this time is called standard time. As you move to the west, the time in each zone is one hour earlier than the previous time zone When it is 1 a.m. in New York City, what time is it in Denver?
2. Base your answer to the following question on the map below which represents a view of the Earth looking down from above the North Pole (N.P.), showing the Earth's 24 standard time zones. The Sun's rays are striking the Earth from the right. Points A, B, C, and D are locations on the Earth's surface. 4. Base your answer to the following question on The diagram below represents the direction of Earth s rotation as it appears from above the North Pole. Point X is a location on Earth s surface. The time at point X is closest to A) 6 a.m. B) 12 noon C) 6 p.m. D) 12 midnight Areas within a time zone generally keep the same standard clock time. In degrees of longitude, approximately how wide is one standard time zone? A) 7 º B) 15º C) 23 º D) 30º 3. The time required for one Earth rotation is about A) one hour B) one day C) one month D) one year
5. Base your answer to the following question on the United States time zone map shown below. The dashed lines represent meridians (lines of longitude). The basis for the time difference between adjoining time zones is Earth's A) 1 per hour rate of revolution B) 1 per hour rate of rotation C) 15 per hour rate of revolution D) 15 per hour rate of rotation
6. Base your answer to the following question on Letters A, B, C, D, and X on the map below represent locations on Earth. The map shows the latitude-longitude grid. Solar time is based on the position of the Sun. If the solar time is 1 p.m. at location X, at which location is the solar time 5 p.m.? A) A B) B C) C D) D
7. Base your answer to the following question on the map below. Letters A through F are locations on Earth s surface. When solar time at location E is 12 noon, solar time at location A is closest to A) 6 a.m. B) 8 a.m. C) 12 noon D) 4 p.m.