Places to the east of the prime meridian have east longitude. The international date line determines where on earth the date changes. For example, at the same moment the time is am on July 1st in Bangladesh, the time is pm on June 30th in Mexico and midnight on June 30th in England see Fig.
Places located immediately to the right and left of the date line are 24 hours apart. Travelers who cross the dateline heading west lose a day, but travelers who cross the dateline going east gain a day. When traveling east across the dateline, it is actually possible to arrive at your destination earlier than when you left!
For practical purposes, the international date line has been adjusted to allow certain land areas to remain together in the same day and time zones. For example, the extreme eastern tip of Russia, which juts into the Bering Strait, was kept in the easternmost time zone, whereas the U.
In another example, the country of Kiribati pronounced KIRR-i-bas drastically changed the date line in so that the entire country could be on the same day at the same time. Before this, the western part of Kiribati, where the capital lies, would be 22 hours ahead of the eastern portion of the county. Lines of latitude and longitude form an imaginary global grid system, shown in Fig.
Any point on the globe can be located exactly by specifying its latitude and longitude. This system is essential for ships at sea that cannot locate their positions using landmarks or coastal navigational aids such as buoys or channel markers. This system is just as useful for people on land when hiking, driving, or surveying an environment.
To locate a point on a globe exactly, degrees of latitude and longitude are further subdivided into minutes and seconds. In latitude and longitude measurements, minutes and seconds do not refer to time. Instead, they refer to parts of an angle. But, like with time, there are 60 minutes in a degree just as there are 60 minutes in an hour. Similarly, there are 60 seconds in a minute of time and 60 seconds in a minute of longitude or latitude.
The latitude and longitude readings of a place are called its spherical coordinates. Make three maps of a globe: an orthographic-projection map, a cylindrical-projection map, and an equal-area map.
If the latitude and longitude coordinates of a location are known, it can be pinpointed on a map or globe. Knowing the spherical coordinates of a location is useful for people when hiking, diving, or surveying an environment. Sophisticated navigational aids use latitude and longitude to give directions when driving and flying. The spherical coordinate system is essential for ships at sea that cannot locate their positions using landmarks or coastal navigation aids like buoys or channel markers.
In addition to using latitude and longitude to specify location, marine and air navigators also use the nautical mile as their unit of length or distance. A nautical mile is approximately one minute of latitude along a line of longitude, a distance of 1.
Navigators describe the speed of ships and airplanes in knots. Old Faithful is higher above sea level than most locations at 7, ft m. Of course, the highest point on Earth, Mount Everest, is much higher at 29, ft m.
Satellites continually orbit Earth and can be used to indicate location. A global positioning system receiver detects radio signals from at least four nearby GPS satellites.
The receiver measures the time it takes for radio signals to travel from a satellite and then calculates its distance from the satellite using the speed of radio signals.
By calculating distances from each of the four satellites the receiver can triangulate to determine its location. Direction is important if you want to go between two places. Directions are expressed as north N , east E , south S , and west W , with gradations in between. Since the magnetic north pole is Without using a compass, we can say that to get to Old Faithful, you enter Yellowstone National Park at the South Entrance, drive north-northeast to West Thumb, and then drive west-northwest to Old Faithful.
Use this resource to answer the questions that follow. Improve this page Learn More. Skip to main content. Module 1: Science of Geology. Search for:. Reading: Location and Direction If you found this feature while out in the field, could you find it again?
Latitude usually comes first in the pairing. Longitude increases as you go East, making Eastern Hemisphere i. New York, for example, is at about 40, Longitude runs from degrees West to degrees East. Since longitude wraps around the Earth, and are the same line, on the opposite side from the prime meridian.
Using the map, can you find some cities in the southeastern hemisphere? While much of the worth is solidly within hemisphere quadrants, there are many cities that straddle one of the zero points.
These cities, by definition, must be either along the equator or the prime meridian i. The map shows 22 cities that are within two and a half degrees of the equator. You can find them by using the grouping function in the lower left corner of the map. Since zero longitude is within densely populated Europe, there are more places that are close to this human-created coordinate. The closest, of course, is London—or Greenwich, specifically. There are 44 cities on the map that are closest to 0 longitude.
Yet, there are only a dozen that are less than one degree from zero. A much less populated place? The opposite of the prime meridian. Move the map around and see if you can find them! Ah, Paris. The City of Lights.
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