Find an Antipode on the Opposite Side of the Earth

Find an Antipode on the Opposite Side of the Earth

An antipode is a point on the opposite side of the Earth from another point; the place you'd end up if you were able to dig directly through the Earth. Unfortunately, if you try to dig to China from most places in the U.S., you would end up in the Indian Ocean as the Indian Ocean contains most of the antipodes for the United States.

How to Find an Antipode

When locating your antipode, recognize that you'll be flipping hemispheres in two directions. If you're in the Northern Hemisphere then your antipode will be in the Southern Hemisphere. And, if you're in the Western Hemisphere then your antipode will be in the Eastern Hemisphere.

Here are some steps to manually compute an antipode.

  1. Take the latitude of the place for which you want to find the antipode and convert it to the opposite hemisphere. We'll use Memphis as an example. Memphis is located at approximately 35° North latitude. The antipode of Memphis will be at 35° South latitude.
  2. Take the longitude of the place for which you want to find the antipode and subtract the longitude from 180. Antipodes are always 180° of longitude away. Memphis is located at approximately 90° West longitude, so we take 180-90=90. This new 90° we convert to degrees East (from the Western Hemisphere to the Eastern Hemisphere, from degrees west of Greenwich to degrees east of Greenwich) and we have our location of Memphis' antipode - 35°S 90°E, which is in the Indian Ocean far to the west of Australia.

Digging Through the Earth From China

So where exactly are the antipodes of China? Well, let's compute the antipode of Beijing. Beijing is located at approximately 40° North and 117° East. So with step one above, we are looking for an antipode that is 40° South (converting from Northern Hemisphere to Southern Hemisphere). For step two we want to move from the Eastern Hemisphere to the Western Hemisphere and subtract 117° East from 180 and the result is 63° West. Therefore, the antipode of Beijing is located in South America, near Bahia Blanca, Argentina.

Antipodes of Australia

How about Australia? Let's take an interestingly named place right in the middle of Australia; Oodnadatta, South Australia. It is the home of the highest recorded temperature on the continent. It's located near 27.5° South and 135.5° East. So we're converting from Southern Hemisphere to Northern Hemisphere and Eastern Hemisphere to Western Hemisphere. From step one above we turn 27.5° South to 27.5° North and take 180-135.5=44.5° West. Therefore the antipode of Oodnadatta is located in the middle of the Atlantic Ocean.

Tropical Antipode

The antipode of Honolulu, Hawaii, located in the middle of the Pacific Ocean is located in Africa. Honolulu is located near 21° North and 158° West. Thus the antipode of Honolulu is located at 21° South and (180-158=) 22° East. That antipode of 158° West and 22° East is in the middle of Botswana. Both locations are within the tropics but Honolulu is located near the Tropic of Cancer while Botswana lies along the Tropic of Capricorn.

Polar Antipodes

Finally, the antipode of the North Pole is the South Pole and vice-versa. Those antipodes are the easiest on the Earth to determine.