A cohort is a group of people who share a common characteristic or experience within a defined period (e.g., are currently living, are exposed to a drug or vaccine or pollutant, or undergo a certain medical procedure).
A rift valley is a lowland region formed by the interaction of Earth's tectonic plates. This small rift valley has a typical formationâlong, narrow, and deep. It was formed by the Thingvellir rift, where the North American and Eurasian tectonic plates are tearing, or rifting, apart over a hotspot on the island of Iceland.
Report Abuse. The Great Rift Valley is a name given in the late 19th century by British explorer John Walter Gregory to the continuous geographic trough, approximately 6,000 kilometres (3,700 mi) in length, that runs from northern Syria in Southwest Asia to central Mozambique in East Africa.