DO NOW Which direction is measured by latitude

DO NOW Which direction is measured by latitude? By longitude?

HOW DOES TIME CHANGE?

Measuring Longitude 1. Longitude is determined by time.

Measuring Longitude 1. Longitude is determined by time. 2. Earth ROTATES 360° in 24 hours.

Measuring Longitude 1. Longitude is determined by time. 2. Earth ROTATES 360° in 24 hours. 3. The rate of rotation then is 15°/hour.

Measuring Longitude 1. Longitude is determined by time. 2. Earth ROTATES 360° in 24 hours. 3. The rate of rotation then is 15°/hour. 4. The Earth rotates COUNTERCLOCKWISE from WEST to EAST.

Measuring Longitude 5. Local NOON (12: 00) at any location always occurs when the sun is directly OVER a meridian.

Measuring Longitude 5. Local NOON (12: 00) at any location always occurs when the sun is directly OVER a meridian. 6. Longitude can be calculated by finding the TIME difference in hours between local sun time and Greenwich Mean Time (the time at the prime meridian and abbreviated as GMT. )

Measuring Longitude 7. If local time is EARLIER than GMT, longitude is west.

Measuring Time 7. If local time is EARLIER than GMT, longitude is west. 8. If local time is LATER than GMT, longitude is east.

Time and Longitude on Maps Time decreases Time increases

World Time Zones NOTE that time is calculated from the prime meridian. Positive #’s means a time later than at GMT. Negative #’s means time is earlier than at GMT.

Time Zones: USA

Science Gnus: Point A is on the prime meridian and the time is 4: 00 p. m. Point B is on 75°W longitude. What is the time at point B?