TANZANIA

TANZANIA.

Rift Valley and Lake Manyara.
Thirt stamp in a set of 5, issued on 22.07.2003.
Face value: 500 Tanzanian shilingi.
Printed by Calcutta Security Printers Ltd.
Printing: Offset lithography.
Size: 39 x 29 mm.

Catalogs
- Michel No. 4105.
- Scott No. 2278.
- StampWorld No. 4133.
- Stanley Gibbons No. 2361.

The East African Rift is an active continental rift zone in East Africa. It began developing around the onset of the Miocene, 22–25 million years ago. In the past it was considered to be part of a larger Great Rift Valley that extended north to Asia Minor. The East African Rift consists of two main branches. The Eastern Rift Valley includes the Main Ethiopian Rift, running eastward from the Afar Triple Junction, which continues south as the Kenyan Rift Valley. The Western Rift Valley transects through Ethiopia, Kenya, Congo DR, Uganda, Rwanda, Burundi, Zambia, Tanzania, Malawi and Mozambique, and it includes a number of active and dormant volcanoes, among them: Mount Kilimanjaro, Mount Kenya, Mount Longonot, Menengai Crater, Mount Karisimbi, Mount Nyiragongo, Mount Meru and Mount Elgon, as well as the Crater Highlands in Tanzania.

Lake Manyara is a lake located in Monduli District of Arusha Region, Tanzania. Its surface area is 470 km² (180 sq mi). It is a shallow, alkaline lake in the Natron-Manyara-Balangida branch of the East African Rift. The northwest quadrant of the lake (about 200 km²) is included within Lake Manyara National Park and it is part of the Lake Manyara Biosphere Reserve, established in 1981 by UNESCO as part of its Man and the Biosphere Programme. The lake is in a closed basin with no outflow, wherein water is only lost by evaporation. It is fed by underground springs, but the vast majority of the inflow comes from rainwater fed permanent and ephemeral rivers that drain the surrounding catchment. In extreme dry periods the surface area of the lake shrinks as the waters evaporate and at times the lake has dried up completely.