The most obvious extreme points in the world are the North and South Poles. The imaginary line through the North and South Poles creates the axis around which the world rotates. As such, these are called the geographical poles. There are also magnetic north and south poles, which is where all compasses point. The North and South Poles are both located in extremely cold territory — the North Pole in the Arctic Ocean, the South Pole on one side of the continent of Antarctica. The South and North Pole were reached by expeditions in 1911 and 1908, respectively.
Other famous extreme points are the world's highest and lowest elevations. The world's highest point is Mt. Everest, in Tibet, with an elevation 8,848 m (29,028 feet) above sea level. This is slightly less than 5 1/2 miles above sea level. Mt. Everest was summited for the first time in 1953. Over 200 climbers have died on its hazardous slopes.
The world's lowest elevation on dry land is the shores of the Dead Sea, at 420 meters (1,378 ft) below sea level. Even lower is the Bentley Subglacial Trench, located in Antarctica, at 2,555 meters (8,327 ft) below sea level, which is the lowest point on the Earth's surface not covered by ocean, although it is covered by ice. The most extreme point of low altitude in the oceans is the Challenger Deep, at the bottom of the Mariana Trench: 10,911 m (35,797 feet) below sea level. The water pressure here is about 1095 atmospheres, over 10 times the surface pressure of the planet Venus. The Challenger Deep has only been visited once by human beings: Don Walsh and Jacques Piccard in 1960 in the bathyscape Trieste.
Other extreme points in the world involve temperature. In 1922, at El Azizia, Libya, a temperature of 57.8 °C (136 °F) was measured. Second place is a temperature of 56.7 °C (134 °F) measured in Death Valley, California, in 1913. Under these temperatures, you'd probably want to spend most of your time in front of heavy air conditioning.
The coldest extreme point in the world is Vostok Station, Antarctica, located near the Southern Pole of Inaccessibility. A temperature of −89.6 °C (−128.6 °F) was measured there in 1983. It is likely that even colder temperatures were reached in the area, near the summit of the local ice sheet, as temperature reliably decreases with altitude.
Michael is a longtime WiseGEEK contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.