Rift Valley lakes

The Rift Valley lakes are a group of lakes in the East African Rift that runs north-south through the eastern side of the African continent from Ethiopia in the north to Malawi in the south. These lakes include some of the oldest, largest, and deepest lakes in the world. Many are freshwater ecoregions of great biodiversity, while others are alkaline "soda lakes" supporting highly specialised organisms.

The Rift Valley lakes are well known for the evolution of at least 800 cichlid fish species that live in their waters. More species are expected to be discovered.

The World Wildlife Fund has designated these lakes as one of its Global 200 priority ecoregions for conservation.

In this article, the major lakes are listed, generally in order from north to south, and more detailed articles on each lake can be accessed through the linked names.

Geology

The East African Rift came into being approximately 40 million years ago as the African tectonic plate began to split. Lakes such as Lake Malawi and Lake Tanganyika have formed in the various valleys of the rift zone, including the huge Lake Victoria.

Valley Wetlands

Valley Wetlands (Welsh: Gwlyptiroedd y Fali), formerly Valley Lakes, is a nature reserve in Anglesey, Wales belonging to the Royal Society for the Protection of Birds. It is an area of lakes and reedbeds to the south-east of Valley in Llanfair-yn-Neubwll community, adjacent to RAF Valley airfield. The western section of the reserve includes Llyn Penrhyn, Llyn Treflesg and part of Llyn Dinam. The eastern part includes Llyn Traffwll and wetlands along the Afon Crigyll. Much of the reserve is included within two Sites of Special Scientific Interest.

Breeding birds include good numbers of sedge and reed warblers which have been joined in recent years by Cetti's warbler. Several species of duck breed including shoveler, gadwall and pochard. Outside the breeding season, duck numbers increase and bittern and marsh harrier are regularly seen. Several rare birds have been recorded such as whiskered tern, green-winged teal and ring-necked duck.

The reserve is rich in wetland plants with large areas of reed and willow and uncommon species such as eight-stamened waterwort, flowering rush, marsh fern and hop sedge. Among the insects are hairy dragonfly, variable damselfly and various water beetles. Mammals include otter and water vole.

Rift valley

A rift valley is a linear-shaped lowland between several highlands or mountain ranges created by the action of a geologic rift or fault. A rift valley is formed on a divergent plate boundary, a crustal extension, a spreading apart of the surface, which is subsequently further deepened by the forces of erosion. When the tensional forces were strong enough to cause the plate to split apart, a center block dropped between the two blocks at its flanks, forming a graben. The drop of the center creates the nearly parallel steeply dipping walls of a rift valley when it is new. That feature is the beginning of the rift valley, but as the process continues, the valley widens, until it becomes a large basin that fills with sediment from the rift walls and the surrounding area. One of the best known examples of this process is the East African Rift. On Earth, rifts can occur at all elevations, from the sea floor to plateaus and mountain range in continental crust or in oceanic crust. They are often associated with a number of adjoining subsidiary or co-extensive valleys, which are typically considered part of the principal rift valley geologically.

Rift Valley

In order of specificity, Rift Valley can refer to: