The Scar That Became a Beauty Spot—The Great Rift Valley
By “Awake!” correspondent in Kenya
THIS “scar” on earth’s face has been photographed from the Apollo 17 spacecraft 90,000 miles (145,000 kilometers) out in space. It extends some 6,000 miles (9,700 kilometers) and varies in width from five to 50 miles (8 to 80 kilometers), but it is by no means a straight trench. Geological surveys show it to be complex and dendritic—having branches and offshoots. Undoubtedly it was caused by tremendous forces wrenching at earth’s crust, resulting in huge subsidences to produce for our delight and wonder some of the most beautiful and unique scenic grandeur of our planet. It is the Great Rift Valley.
It was not until the latter part of the 19th century, with the opening up of East and Central Africa to exploration, that the full extent of this geological wonder could be appreciated. After a visit to East Africa in 1893, J. W. Gregory, a Scotchman, reported to fellow geologists: “For this type of valley I suggest the name of Rift Valley, using the term rift in the sense of a relatively narrow space due to subsidence (sinking or settling) between parallel fractures. Such valleys are known in many parts of the world, but that of East Africa may justly be called the Great Rift Valley.”
From Asia to the Indian Ocean
The East African portion may aspire to be the most glamorous section of this geological fault. The phenomenon commences its appearance between the Lebanon and Anti-Lebanon mountains in Asia and continues southward through the Jordan Valley trench, including the Sea of Galilee, the Dead Sea and the Gulf of ‘Aqaba. It proceeds through the Red Sea and enters Africa in Ethiopia opposite the confluence of the Gulf of Aden and the Red Sea. In Kenya, Uganda and Tanzania the Rift Valley becomes more complex as it approaches the equator. The wider western branch of the Rift follows Lakes Mobutu (formerly Albert), Idi Amin (formerly Edward), Kivu, Tanganyika and Rukwa through Uganda, Zaïre, Rwanda, Burundi and Tanzania. The eastern branch follows the line of Lakes Zwai, Shala, Abaya, Turkana (formerly Rudolph), Baringo, Nakuru, Naivasha, Natron and Eyasi through Ethiopia, Kenya and Tanzania. Thus Lake Victoria is skirted on both sides, and the branches merge in southern Tanzania. The Rift proceeds from there through Lake Malawi into Mozambique and thence to the Indian Ocean.
Mighty forces have caused this giant rupture and decorated it with exalted snowcapped beauty in places. As evidence that violent subterranean powers were at work in the East African Rift Valley, we find some 30 active or semiactive volcanoes from the shores of the Red Sea in Ethiopia to Mounts Meru (14,979 feet; 4,566 meters) and Kilimanjaro (19,340 feet; 5,895 meters) in Tanzania.
It was at its southernmost tip that my family and I first saw the Great Rift Valley. On a visit to the Inyanga Mountains in the northeastern area of Rhodesia we were able to approach an ‘edge of the world’ vantage point from which we could view a sheer drop of some 2,000 feet (610 meters) into the valley floor below. Then on another occasion at the Rift’s northern extremity, we took the road that leads from Beirut to Baalbek in Lebanon. From an elevation of 4,500 feet (1,370 meters) on the Lebanon range we looked across the Bekáa Plain to the Anti-Lebanon mountains, another very impressive view of the Rift Valley.
For sheer Rift Valley beauty and grandeur there can be little to rival the scene to be enjoyed on the road from Nairobi to Nakuru in Kenya. Just before a person descends the escarpment in a series of hairpin bends he can gaze on a wide yellow plain stretching north and south as far as the eye can see, and bounded on the east and west by almost vertical cliff walls. In this part of the valley lie several lakes, including Naivasha and Nakuru, decorating the Rift with the finest aviary in the world.
Northern End of the Rift
Let us take an armchair trip through the Great Rift Valley from north to south. Although conspicuously narrower, the Jordan–Dead Sea rift lacks nothing in outstanding features and beauty. It was land in this general area that the Bible thus described in Deuteronomy 8:7-9: “Jehovah your God is bringing you into a good land, a land of torrent valleys of water, springs and watery deeps issuing forth in the valley plain and in the mountainous region, a land of wheat and barley and figs and pomegranates, a land of oil olives and honey, a land in which you will not eat bread with scarcity, in which you will lack nothing.” Standing as a sentinel overlooking this valley is the beautiful Mount Hermon (9,000 feet; 2,700 meters). Flowing through the Rift, the Jordan River traverses the Sea of Galilee and terminates in that lowest spot on earth, the Dead Sea. Here the surface water is measured at 1,292 feet (394 meters) below the level of the Mediterranean Sea. The water of the Dead Sea is about 25 percent solids, mostly common salt.
The eastern side of the Rift, extending from Mount Hermon through the Jebel Druze region, is a long line of volcanic peaks, extinct craters and great outflows of lava rising at the highest point to more than 3,000 feet (over 900 meters), giving witness to early eruptions. In this Bible land, earthquakes and volcanic activity have not been infrequent. Serious earthquakes have occurred in Palestine about every 50 years, minor tremors being more frequent. It is of these that rift valleys are born.
Through the Sea and On into Africa
As the Rift Valley continues into the Red Sea trench it enters an area unusual in its geology and ecology. This sea has a higher salinity than any other part of the oceans, and in contrast to the cold-water depths of most oceans, its abyssal waters can reach temperatures of 138 degrees Fahrenheit (59 degrees Celsius) in volcanic depths. It is described as a precipitous trench that is as much as a mile and a half deep down the middle of its entire length. The profusion of different corals and the richness of marine life make it one of the most glamorous “garden-aquariums” on the earth.
The Rift Valley system now takes a turn overland, roughly between Massawa, the Ethiopian Red Sea port, and a point in Somalia, southeast of Djibouti. Here at its widest point it soon enters the Danakil Depression, lying 400 feet (120 meters) below sea level. A string of some 14 active or semiactive volcanoes dots the map through this region, pointing up the violent subterranean forces still present in this giant fissure. In this area we find the Karum Salt Lake with its salt pinnacles and multi-colored pools surrounding Mount Dallol, giving the region a prehistoric appearance and strange beauty. The sea-salt deposit at Lake Karum is 3,700 feet (1,128 meters) thick and the temperature of the surface rock in the Danakil gets as high as a sizzling 320 degrees Fahrenheit (160 degrees Celsius).
East African Branches
The thin edge of the valley wedge now is reduced to some 30 miles (50 kilometers) in width, which it uniformly keeps and continues throughout the system of branches in East Africa. After the display of volcanoes in the Danakil, the Rift Valley now puts on another show with a string of quiet but beautiful lakes from Zwai to Chew Bahir (formerly Stephanie). One of these, Lake Shala, which takes its name from the Galla (or, Oromo) people’s word for “pelican,” has only in recent years given up its secret as to why pelicans should breed there in thousands when this lake contains few fish suitable to the pelican diet. These beautiful fliers are now known to commute on thermal air currents over the mountain to Lake Abiata, which teams with tilapia (a fish), and to return in 24 hours with supplies to feed their brood in the seclusion of Lake Shala. Remote Lake Turkana (formerly, Rudolph), sometimes referred to as the Jade Sea, now embellishes the valley as it leaves Ethiopia and enters Kenya, and it is here that the eastern and western branches become evident.
The Great Rift Valley provides facilities to make it one of the most heavily traveled bird migration routes in the world. Some of the many beautiful lakes that glisten in the African sun are of fresh water, like Lakes Zwai, Awasa, Naivasha and Baringo. Others have only a slight soda content, so that they all provide excellent watering places for migratory stopovers. The towering walls of the Rift Valley provide hundreds of miles of air thermals that rise up the steep escarpments and keep the eagles, hawks and storks aloft. Smaller birds like swallows and wheatears fly through the Rift on their way to Europe and Russia.
The large lakes, Magadi and Natron, on the eastern branch, very high in soda content, furnish one of the mysteries of the East African Rift Valley. The seemingly unending supply of washing soda is thought to be a product of the thermal bowels of the Rift. The mystery surrounds the water supply, as it is not apparent in the vicinity of the lakes, but the underground plumbing system remains tremendously potent. Because of the inhospitable nature of the caustic flats at Lake Natron, it was not appreciated until as recently as 25 years ago that the lake provided the breeding ground for almost all the vast East African population of flamingos.
The western arm of the East African Rift is prominently marked by the larger lakes, Mobutu (Albert), Idi Amin (Edward), Kivu and Tanganyika, all in scenic settings with impressive backdrops rising steeply more than 5,300 feet (1,600 meters). Lake Tanganyika is the second-deepest lake in the world, at a depth of some 5,000 feet (1,500 meters). On this branch of the Rift the Ruwenzori mountain range (the legendary Mountains of the Moon) rises to peaks of up to 16,794 feet (over 5,100 meters) above the valley floor.
The eastern and western branches now appear to merge again and beautiful Lake Malawi becomes one of its distinctive features as it cleaves its way through Mozambique and into the Indian Ocean.
Although, in terms of both process and time, the development of the Great Rift Valley system may not be completely understood by geologists, these inspired words of the Bible explain its origin: “Mountains proceeded to ascend, valley plains proceeded to descend—to the place that you have founded for them.” Only a loving Creator could transform such a scar into a beauty spot.—Ps. 104:8.
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The Great Rift Valley System
REPUBLIC OF ZAÏRE
L. Idi Amin