Extremes on Earth
This article lists extreme locations on Earth that hold geographical records or are otherwise known for their geophysical or meteorological superlatives. All of these locations are Earth-wide extremes; extremes of individual continents or countries are listed in separate articles under the Extreme points by region section. For other lists of extreme places on Earth, see Lists of extreme points. For more detailed meteorological and climatic records, see List of weather records. Latitude and longitude. Longest grid lines. Along any geodesic. These are the longest straight lines that can be drawn between any two points on the  surface of the Earth and remain exclusively over land or water; the points need not lie on the same line of latitude or longitude. Along any truly straight line. As distinct from all of the aforementioned geodesic lines, which may appear straight but are actually arcs of great circles projected on the spheroidal surface of the Earth and, accordingly, are not truly straight but rather curving lines, authentically straight lines can be projected through the interior of the Earth between almost any two points on the surface of the Earth (some extreme topographical situations being the rare exceptions). If a  line projected from the summit of Cayambe in Ecuador (see highest points) through the axial centre of the Earth to its antipode on the island of Sumatra, then the resulting diametrical line would be the longest truly straight line that could be produced anywhere on or through the Earth. As the variable circumference of the Earth approaches , such a maximum "diametrical" or "antipodal" line would be on the order of long. Remoteness. Poles of inaccessibility. Each continent has its own continental pole of inaccessibility, defined as the place on the continent that is farthest from any ocean. Similarly, each ocean  has its own oceanic pole of inaccessibility, defined as the place in the ocean that is farthest from any land. Farthest-apart cities. The pairs of cities (with a population over 100,000) with the greatest distance between them (antipodes) are: The pair of airports with scheduled flights having the greatest distance between them has been measured to be Sultan Mahmud Badaruddin II International Airport, which serves Palembang, Indonesia, and Benito Salas Airport, which serves Neiva, Colombia, located about 10,819 nautical miles (20,037 km) apart. Centre. Since the Earth is a spheroid, its centre (the core) is thousands of kilometres beneath  its crust. Still, there have been attempts to define various "centrepoints" on the Earth's surface. Geophysical extremes. Deepest ice. Ice sheets on land, but having the base below sea level. Places under ice are not considered to be on land. Meteorological extremes. Ground temperatures. Temperatures measured directly on the ground may exceed air temperatures by 30 to 50 °C. A ground temperature of 84 °C (183.2 °F) has been recorded in Port Sudan, Sudan. A ground temperature of 93.9 °C (201 °F) was recorded in Furnace Creek, Death Valley, California, United States on 15  July 1972; this may be the highest natural ground surface temperature ever recorded. The theoretical maximum possible ground surface temperature has been estimated to be between 90 and 100 °C for dry, darkish soils of low thermal conductivity. Satellite measurements of ground temperature taken between 2003 and 2009, taken with the MODIS infrared spectroradiometer on the Aqua satellite, found a maximum temperature of 70.7 °C (159.3 °F), which was recorded in 2005 in the Lut Desert, Iran. The Lut Desert was also found to have the highest maximum temperature in 5 of the 7 years measured (2004 , 2005, 2006, 2007 and 2009). These measurements reflect averages over a large region and so are lower than the maximum point surface temperature. Satellite measurements of the surface temperature of Antarctica, taken between 1982 and 2013, found a coldest temperature of −93.2 °C (−136 °F) on 10 August 2010, at . Although this is not comparable to an air temperature, it is believed that the air temperature at this location would have been lower than the official record lowest air temperature of −89.2 °C.