Latitude and Longitude — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
The International Date Line follows the meridian at zero degrees longitude across the Pacific.
Corrected: The International Date Line follows the meridian at 180 degrees longitude across the Pacific.
The International Date Line roughly follows the 180-degree meridian, opposite the Prime Meridian, where each new calendar day begins.
2. Fix the sentence:
Earth has 12 standard time zones, each spanning 30 degrees of longitude on the globe.
Corrected: Earth has 24 standard time zones, each spanning 15 degrees of longitude on the globe.
Earth has 24 time zones because 360 degrees divided by 24 hours equals 15 degrees of longitude per time zone.
3. Fix the sentence:
When you cross the Date Line traveling west, you subtract one day from the calendar.
Corrected: When you cross the Date Line traveling west, you add one day to the calendar.
Crossing the International Date Line westward advances the calendar by one day, while eastward travel moves it back one day.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. The International Date Line runs near the 180-degree meridian through the Pacific Ocean.
The International Date Line is an imaginary line near 180 degrees longitude that separates one calendar day from the next.
2. Each standard time zone covers 15 degrees of longitude around our spinning planet.
Time zones are defined by longitude because Earth rotates from west to east, causing the sun to rise at different longitudes at different times.
3. The Prime Meridian at 0 degrees longitude passes through Greenwich, England, near London.
The Prime Meridian passes through Greenwich, England, and serves as the starting point for measuring longitude and Greenwich Mean Time.
4. Crossing the Date Line going east means you go back one calendar day on your trip.
Eastward crossings of the International Date Line subtract one day from the calendar, so travelers experience the same date twice.
Part C: Short Answer
Answer each question in one or two complete sentences.
1. Why was the International Date Line placed at 180 degrees longitude in the Pacific Ocean?
Sample answer: It was placed there because 180 degrees is opposite the Prime Meridian and runs mostly through open ocean, avoiding confusion in populated land areas.
Placing the Date Line in the open Pacific Ocean keeps the calendar change away from densely populated regions and most countries' borders.
2. How does longitude help create time zones for navigation and daily life on Earth?
Sample answer: Longitude divides Earth into 24 sections of 15 degrees each, with each section representing one hour, allowing places to set local time based on the sun's position.
Longitude lines divide Earth into 24 time zones of 15 degrees each, matching Earth's rotation rate so noon occurs when the sun is highest at each location.