Embedded Files
We learned previously that Latitude, the measurement of distance north or south of the equator, directly influences climate. Regions near the equator (0° latitude) receive the most direct sunlight year-round, resulting in consistently warm temperatures and tropical climates. Moving toward the poles (90° North and South), sunlight is less direct, leading to cooler temperatures and polar climates. Mid-latitude regions experience seasonal variations due to the Earth's axial tilt, causing different levels of solar exposure throughout the year.
Today we are going to examine Longitude more closely. As you know, longitude measures the distance east or west of the Prime Meridian (0° longitude). If latitude is a measure of the distance from the Equator and therefore an indicator of climate zones, what does longitude measure in addition to the distance from the Prime Meridian?
Which animation is correct below? Why?
Which animation is correct below? Why?
Animation A Animation B
Establishing Time Zones
Establishing Time Zones
How many hours are in a day?
How many degrees are in a circle?
If the earth rotates 360 degrees in one day, how many degrees does the earth rotate in an hour?
Sir Sanford Fleming, a Canadian engineer, was the first person to propose the use of worldwide time zones back in 1878. His idea was to divide the world into 24 time zones that were each 15 degrees of longitude apart. The reason for this is that the earth rotates 15 degrees every hour, or 360 degrees in 24 hours.
GMT or UTC or Z Time?
GMT or UTC or Z Time?
The Prime Meridian, or zero degrees longitude, passes through Greenwich Village England where the Royal Observatory resides. Hence, some countries all relate to time at the time zone where the Prime Meridian is located as Greenwich Mean Time or GMT. Some people mistakenly call it Coordinated Universal Time or UTC.
The difference between GMT and UTC is that UTC is the world's standardized system of keeping time while GMT is a timezone in the system. The U.S. military calls the time at GMT "Zulu" time or "Z" time .
We live in the -6 UTC or -6 GMT. Which means we are 6 hours behind the time at the Prime Meridian. If it is 7pm in Greenwich England (UTC 0), then it is 1pm in Coal City (UTC -6).
Eastern Australia on the other hand is +10 UTC/GMT which means they are 10 hours ahead of the time in England or 16 hours ahead of us in Coal City.
How many hours difference is it between China and us here in Coal City?
Do a "180 Degrees" to Become a Time Traveler
As you learned earlier, the Prime Meridian is at 0 degrees longitude. On the opposite side of the globe is 180 degrees longitude or the AntiMeridian. Like at the Prime Meridian, this is where the Eastern hemisphere and Western Hemisphere meet up again.
The International Date Line (IDL) is also an imaginary line that runs from the North to the South Pole and separates two calendar days. The IDL is important in measuring time and is crucial for instantaneous communication, politics, and commerce.The IDL is an imaginary line that roughly follows the 180° line of longitude and passes through the Pacific Ocean. However, this line is not straight and strays from the 180° meridian at certain points. In some places, it appears as zig-zag, deviating to the meridian’s east or west. The deviations enable places of the same economic and political affiliations to share the same date or time. Otherwise, if the IDL were a straight line, it would divide certain countries into two parts with two different dates on the same day.
Central or "Confusion" Time
We live in U.S. Central Time. Due to Daylight Savings Time (DST) clock changes in March and November of each year, there are parts of the year that we will be UTC -5 or GMT -5 due to the hour change (Central Daylight Time or CDT) rather than the -6 GMT Central Standard Time or CST. The following shows the current year in Chicago. Central Daylight Time is -5 GMT (while under DST) and Central Standard Time we are -6 GMT when NOT under DST.
By the way, GMT or UTC never changes for Daylight Savings Time though the United Kingdom does.
There are 4 time zones In the continental U.S: Eastern, Central, Mountain, and Pacific. As the Earth rotates on its axis from West to East the sun appears to rise in the East. Therefore, places relatively East of places see the start of a day first. Because of this, Miami (Eastern Time Zone) is one hour ahead of Chicago (Central Time Zone) and San Francisco (Pacific) is 3 hours behind Miami (Eastern) and 2 hours behind Chicago (Central).
If lines of longitude converge at the poles and longitude lines is indicative of time, what time is it at the North Pole?
Page updated
Report abuse