The geosynchronous (also geostationary) orbit that satellites are placed into. It was named after Arthur C. Clarke who proposed the concept in 1945. See GEO and Clarke's laws.
"Clarke belt." YourDictionary, n.d. Web. 18 August 2018. <http://www.yourdictionary.com/clarke-belt>.
Clarke belt. (n.d.). Retrieved August 18th, 2018, from http://www.yourdictionary.com/clarke-belt