Active And Extinct Volcanoes In Kenya

Geomorphology  of Volcanic  Mountains   ACTIVE AND EXTINCT  VOLCANOES IN KENYA.  Omondi Felix Mark 

ACTIVE AND EXTINCT VOLCANOES IN KENYA.

THIS IS A LIST OF ACTIVE AND EXTINCT VOLCANOES IN KENYA. Elevation

Name

Central Island

Mount Elgon

Last Volcanic Landform eruption

meters feet Coordinates 1032 3385 2.32° N 36.57° E 1921 3.50° N 36.042° 550 1804 E

The Barrier

Chyulu Hills

Location

Shaitani 2188 Chainu 4321

7178 2.68° S 37.88° E 1855 14178 1.1° S 34.5° E

Elmenteita Badlands

2126

6975 0.52° S 36.27° E Holocene

Emuruangogolak

1328

4357 1.50° N 36.33° E 1910

Homa Mountain

1751

5745 0.38° S 34.50° E Holocene

Mount Kenya

5199

17057 0°9′S, 37°18′E

Korosi Likaiu

1446 915

Longonot

2776

Marsabit Menengai Namarunu

1707 2278 817

4744 0.77° N 36.12° E Holocene 3000 2.17° N 36.36° E 0.914° S 36.446° 9108 1863 E 5600 2.32° N 37.97° E Holocene 7472 0.20° S 36.07° E 6050 BC 2680 1.90° N 36.27° E 6550 BC

North Island (Kenya)

520

1706 4.07° N 36.05° E -

Nyambeni Hills Ol Doinyo Eburru Ol Kokwe

750 2856 1130

Olkaria

2434

Paka

1697

2460 0.23° N 37.87° E Holocene 9370 0.63° S 36.23° E 3707 0.63° N 36.08° E Holocene 0.904° S 36.292° 7985 1770 E 5568 0.92° N 36.18° E 6050 BC

Segererua Plateau

699

2293 1.57° N 37.90° E Holocene

Silali South Island (Kenya) Suswa

1528 800 2356

5013 1.15° N 36.23° E 5050 BC 2625 2.63° N 36.60° E 1888 7730 1.175° S 36.35° E -

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Shield Volcano Stratovolcano(Composite Cones) Shaitani Cinder Chainu Cinder Stratovolcano(Caldera) Pyroclastic cone(Cinder Cone) Shield Volcano Complex(Composite Cones) Stratovolcano(Volcanic Neck) Shield Volcano Shield Volcano Stratovolcano(Caldera) Shield Volcano Shield Volcano(Caldera) Shield Volcano Tuff Cones(Cinder Cone) Shield Volcano Complex Shield Volcano Pumice Cones(Cinder Cone) Shield Volcano Pyroclastic cone(Cinder Cone-Pyroclastic Flow) Shield Volcano Stratovolcano Shield Volcano(Caldera)

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

1. Mount Elgon • • •

1.13 N, 34.55 E summit elevation 4321 m Extinct Stratovolcano

Mount Elgon is the second highest mountain in Kenya and is an extinct volcano. Mount Elgon is in the far west of Kenya on the Ugandan border. The woodland on the south eastern slopes merges into thick mountain forests. In amongst the forest and caves you will find elephant, buffalo and other animals. Kitum cave is famous as the place where elephant herds enter deep into the mountain each night where they excavate salt. It is possible to drive up to 3,659 meters and then hike across moorland to Koitoboss Peak. Access to Mt Elgon is from the town of Kitale. Mount Elgon is the second highest mountain in Kenya. The volcano is located 140km North East of Lake Victoria and is bisected by the Kenya-Uganda border. Approximately 8km in diameter, Mt. Elgon’s caldera is one of the largest intact calderas in the world. Concerns of volcanic activity were raised in August 2004 after gas emissions were detected in cave on the mountain.Mt Elgon Eruptions 2 million years ago Mount Elgon is an extinct shield volcano on the border of Uganda and Kenya. The mountain is named after the Elgeyo tribe, who once lived in huge caves on the south side of the mountain. It was known as "Ol Doinyo Ilgoon" (Breast Mountain) by the Maasai and as "Masaba" on the Ugandan side. It is the oldest and largest solitary volcano in East Africa, covering an area of around 3500 km².Mt. Elgon consists of five major peaks: • Wagagai (4,321m), being in Uganda. • Sudek (4,302m or 14,140ft) in Kenya • Koitobos (4,222m or 13,248 ft), a flat topped basalt column (Kenya) • Mubiyi (4,211m or 13,816 ft) • Masaba (4,161m or 13,650 ft) In 1896, C.W. Hobley became the first European to circumambulate the mountain. Kmunke and Stigler made the first recorded ascent of Wagagai and Koitobos in 1911. F. Jackson, E. Gedge, and J. Martin made the first recorded ascent of Sudek in 1890. The main peak is an easy scramble and does not require any mountaineering equipment. Other interesting features are: • The caldera — Elgon's is one of the largest intact calderas in the world • The warm springs by the Suam River • Endebess Bluff (2563m or 8408 ft) • Ngwarisha, Makingeny, Chepnyalil and Kitum lava tube caves. Kitum Cave is over 60 metres wide and penetrates 200 metres. It is frequented by wild elephants who lick the salt exposed by gouging the walls with their tusks. It became notorious for its association with the Marburg virus after two people who had visited the cave (one in 1980 and another in 1987) contracted the disease and died. The mountain soils are red laterite. The mountain is the catchment area for the several rivers such as the Suam River which becomes the Turkwel downstream and which drains into Lake Turkana, the Nzoia River and the Lwakhakha which flow to Lake Victoria. The town of

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

Kitale is in the foothills of the mountain. The area around the mountain is protected by two Mount Elgon National Parks one on each side of the international border.

Mt Elgon

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

2. Mount Kenya Mount Kenya is the sacred mountain of the Gikuyu people. Mount Kenya is the second highest mountain in Africa and can be climbed. The walk is relatively easy but you have to be careful of mountain sickness and time is needed to acclimatize. The actual summit is 5199 metres and is only reachable by climbing. Walkers can reach Point Lenana at 4985 metres and takes between 2 and 5 days. The nearest towns to Mount Kenya are Naro Moru and Nanyuki. Mount Kenya is located on the African Rift Valley. Eruptions have been infrequent in recent years, but there will be future volcanic activity. Volcanic activity extends 200 km both east and west of the main Rift Valley and is centered on the Kenya "dome". There is a diversity of volcanic rocks from acid to basic. Volcanism in the northern half of the Kenya Rift Valley began at 30 million years ago, and in the southern half it began at 15 million years ago. Before going on to describe Mount Kenya, some explanation is necessary of the different parts which make up a volcano. The neck is the channel or pipe through which molten lava from the lower crust of the earth rises to the surface. Materials discharged accumulate round the vent and build up a cone. The central depression or crater is kept clear by the explosive up rush of steam, etc. The cone is composed of lava and fragmentary volcanic materials known as ash if very fine-grained, tuff when the ash is consolidated, or agglomerate if the material is coarsegrained. These products are easily destroyed by wind and rain, so that it is only in the more recent volcanoes that we find the cones and craters still preserved. Although the main crater of Mount Kenya has long since been removed by erosion, parasitic cones of a much later date may be seen on the lower slopes of the mountain, many of which have their craters still preserved. The most resistant part of a volcano is the plug of lava which consolidates in the neck and it remains standing long after the lighter materials have been worn away. A mountain in which the plug forms the summit is sometimes known as a volcanic neck: an example is Mount Kenya. Volcanic cauldrons or caldera (as opposed to craters) are caused by subsidence, not up-building, and examples of these are Menengai, near Nakuru, and Ngorongoro (commonly, but erroneously, called Ngorongoro crater) in Tanganyika(Tanzania), which is more than 20 Kilometers across and one of the biggest caldera in the world. The crater of Mount Kenya is thought to have existed some 915 meters above its present summit (5195 meters). The peaks of Nelion and Batian consisting of the plug of the volcano, are composed of nepheline-syenite, a deep-seated igneous rock and not a lava. The various stages in the history of formation of the mountain may be summarized as follows a) Miocene or Pliocene. First eruptions of phonolite, followed by second and main eruptions of kenyte. b) Lower Pleistocene. Third eruptive stage (olivine-basalt), after a long interval between eruptions. c) Denudation, destruction of the crater, and excavation of existing valleys. d) Maximum glaciation during Lower and Middle Pleistocene, with a warmer period between during which the glaciers retreated. The glaciers on the mountain, which number ten at the present time, were first studied by Sir Halford Mackinder in 1903 and were found to end at between 44,060 and 45, 43 0meters. Dr. E. Nilsson has since concluded from the evidence of morrainesl that the glaciers formerly descended 1524 meters lower: to 3,049 meters in fact, and Dr. H. L. Sikes believes that they came as low as 2134 meters (the ice cap on Ruwenzori was lower still). Professor Gregory described fifteen glaciers on Mount Kenya, but five of these have now disappeared and, from observations and photographs taken in the last few years, it is evident

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

that the present glaciers are fast retreating. A few years ago, as Lieut. P. C. Spink remarks, the Curling Pond (at 4,573 meters approximately) extended to within a few meters of the top hut. This year (1948) I' noticed that the ice was about 28 meters from the hut and it looked by no means firm enough to attempt skating, as Mr. Melhuish did about 15 years ago. Whether the general progressive desiccation which is taking place in Kenya will mean the disappearance of the glaciers on Mount Kenya in the near future is a matter for speculation and I believe that no accurate measurements of the retreat of the ice have been taken on Mount Kenya, though Lieut. Spink has attempted to do this on Kilimanjaro over a number of years. Professor Gregory remarks on the contrast between the jagged peaks above the ice zone which are exposed to frost action, and the rounded summits of areas which were formerly covered by ice and thus suffered corrasion by glaciers but were preserved from disintegration by frost (alternate freezing and thawing) under their blanket of ice. In former times when the glaciers descended much lower, they carved out many perfect V-shaped valleys which radiate from the main peaks. Other interesting evidence of a climate which was formerly much colder than it is to-day is afforded by the famous tree-groundsels (Senecio) and giant lobelias found at the higher levels on Mount Kenya and other African mountains (tree-groundsels). The ancestors of these huge plants must have lived at a lower altitude when the climate was colder and, as it became warmer, they retreated up the slopes of the mountains until they became completely isolated and gradually formed distinct species on the tops of the various mountains. In a recent paper Professor F. Zeuner has drawn attention to frost soils on talus slopes between 3963 meters and 4268 meters on Mount Kenya. On strongly inclined slopes striped soil structures are seen, while more level surfaces have structures of network type. In the latter type, fine earth centres about 127-203 millimeters wide occur in a stony background, being separated from each other by borders of 25.4-102 millimeters. The sorting processes responsible for these structures are only active under wet conditions and the main causes of the sorting are "frost heave" and "frost shove" produced by needle ice formation. Frost soils are also observed in the Arctic, but here they are due to seasonal freezing, whereas on Mount Kenya they are caused by the great diurnal variations in temperature. Kenya is indeed a "country of contrasts" and can boast of many striking features, but none I think more imposing than the sight of the glaciers on Mount Kenya at dawn, their snows a delicate pink against deep blue shadows, with the dark mass of the forest belt separating them from the parched brown of the plains beneath. It is not difficult to believe that this aweinspiring mountain is the abode of the gods, as the Wakamba believed, and as such it is fitting that our country should take its name from their word for the mountain, which is "Kirinyaga" (in Kikamba the letters r and g are slurred, so that the word becomes" Ki-i-nyaa").

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

Mount Kenya

Mount Kenya

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

3. Mount Longonot • 0.92 S, 36.45 E, • summit elevation 2617 m • Stratovolcano type of volcano. • Eruptions1863, ~1600, 1330, 1270 BC, and 3650 BC Mount Longonot is 2777m high and rises out of the Rift valley and has a distinct volcanic shape. The name comes from the Maasai world "olonong'ot" which means 'mountain of many spurs'. Whilst dormant the waters just a few thousand metres below the surface are over 300 degrees and one of the hottest on earth. The climb up passes lava fissures and canyons and some game can be seen. The views of the rift Valley are spectacular. Mount Longonot is 60 km north of Nairobi on the old Naivasha – Nairobi road. From the park gate to the summit will take about 6 hours return. 0.92 S, 36.45 E, summit elevation 2617 m stratovolcano type of volcano. Longonot volcano is located SE of Lake Naivasha. Lava flows on the northern flank occurred around 1863. In the mid 20th century 30 fumaroles were reported at the volcano. On the northern flank there is a well preserved parasitis cone and recent-looking lava. Longonot Volcano Eruptions1863, ~1600, 1330, 1270 BC, and 3650 BC.Mount Longonot is a dormant stratovolcano located southeast of Lake Naivasha in the Great Rift Valley of Kenya, Africa. It is thought to have last erupted in the 1860s. Its name is derived from the Maasai word oloonong'ot, meaning "mountains of many spurs" or "steep ridges".Mt. Longonot is protected by the Kenya Wildlife Service as part of Mount Longonot National Park. A trail runs from the park entrance up to the crater rim, and continues in a loop encircling the crater. A forest of small trees covers the crater floor, and small steam vents are found spaced around the walls of the crater. The mountain is home to various species of wildlife, notably zebra and giraffe.Mt. Longonot is 60 kilometres northwest of Nairobi and may be reached from there by a tarmac road. A nearby town is also named Longonot. The Longonot satellite earth station is located south of the mountain.

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

Mt Longonot

Mt Longonot

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

4. Western Highlands The Western Highlands are around Eldoret which has an international airport. Within the region are a number of other airstrips. The main towns are Kericho, Kitale, Kaptagat and Kabaranet. The highlands are a group of hill and ranges with views across the Rift Valley. The Cherengani Hills rise to 3581 metres and lie northwest to Kapenguria. The hills are popular with more adventurous hikers and long hikes are possible. The Tugen Hills provide views across the rift valley to Lake Baringo. The hills around Kericho are covered in tea estates. Saiwa Swamp National Park allows walking and home of the Sitatunga and semiamphibious antelope that lives in the swamps.

5. Shimba Hills Shimba Hills National Reserve is just 50 kms inland from the coast and is an area of open grassland and rainforest. Easy to spot Elephant, Giraffe and Buffalo and if lucky the Roan and Sable antelope. In the forest are found the Black and White Colobus, Red Duiker and Suni Antelope. Access to the Shimba Hills is from Kwale.

6. Taita and Chyulu Hills The Taita Hills are part of the Tsavo area and accessed from Taveta. The Chyulu Hills are young volcanic mountains and formed just over 500 years ago. A black lava known as Sheitani is found lining the hills. Home to elephant,cheetah and plains game and Maasai villages. In Taveta are the Jipe and Chala lakes.

7. Mount Dukana • • • •

Kenya/ Ethiopia border.4.08 N, 37.42 E summit elevation 1067 m Pyroclastic cones. The volcano lies on the Kenyan - Ethiopian boder.Mega Basalt Volcano Eruptions No recent eruptions.

8. North Island Volcano • • • •

4.07 N, 36.05 E Summit elevation 520 m Tuff cones North Island is 2 km wide and located in Lake Turkana in northern Kenya. The last eruption is unknown but there are two unvegetated lava flows on the shore. Geothermal activity is present on the southern half of the island.

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

9. Central Island Volcano (Crocodile Island) • • • •

•

3.50 N, 36.04 E summit elevation 550 m Stratovolcano Central Island is located in Lake Turkana in northern Kenya. The island has 15 craters and cones with three occupied by lakes. One group of craters appears to be more recent with ropy lava and scoriae showing little weathering. Fumarolic activity is present on the rim of the central crater with sulphur covering the walls. All beaches on the island are less than 12 m above sea level which indicates the island structure is recent, due to the fact that water levels have been falling in the lake from a maximum 76 m above the present level. Central Island is vegetated by spiny grass and thorn bush. Central Island Volcano Eruptions 1974?, ~1000 AD

10. South Island Volcano (Honel Island) • • • •

2.63 N, 36.60 E Summit elevation 700 m Stratovolcano South Island is the largest island in Lake Turkana, northern Kenya. There are 16 craters on the island aligned on a central ridge. In the northern part of the island there are lava flows (over 10,000 years old) which reached the coast. Local legends report fires on the island which may have been due to volcanic activity. South Island Volcano Eruptions 1888.

11. Marsabit Volcano (Mount Marsabit) • 2.32 N, 37.97 E • Summit elevation 1707 m • Shield volcano Marsabit is a 6300 km² basaltic shield volcano in Kenya, located 170 km east of the center of the East African Rift. This was primarily built during the Miocene, but some lava flows and explosive maar-forming eruptions have occurred more recently. At least two of the maars host crater lakes. The volcano is covered by dense forest. Marsabit National Park is in the area. Marsabit volcano is located in northern Kenya, east of Lake Turkana. It is a large shield volcano with 180 cinder cones and 22 maars. The volcano contains surface slopes of less than 6 degrees. Lava flows have thickness of 5-20 m. The maars are up to 2.5 km in diameter, and some locally coalesce to form composite craters up to 3.0 km long. Volcanism is concentrated along two belts 15 km long, aligned NE and NW through the summit. Marsabit is the only one of the four major shield volcanoes in northern Kenya which contains many maars. This is due to its location across the Chalbi Basin, which is the main

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

groundwater sink in northern Kenya. The resulting mixing of groundwater and magma has created numerous maars.Marsabit Volcano EruptionsNo recent eruptions.

12. The Barrier Volcano • 2.32 N, 36.57 E • summit elevation 1032 m • Shield volcano The Barrier is a shield volcano located in Kenya. It is known to have last erupted in 1921. Elevation1,032 m (3,386 ft) Location Kenya Coordinates 2°32′N, 36°57′W Type Shield volcano Last eruption 1921 Listing List of volcanoes in Kenya The Barrier is composed of four overlapping shield volcanoes at the southern end on Lake Turkana. The volcano derives its name from its location which is between Lake Turkana and the Suguta Valley (the location of a former lake). The volcano is nearly symmetrical in N-S with slopes of 4-5 degrees. Explosive eruptions and lava flows have been reported at the volcano. The Barrier Volcano Eruptions1921, 1920?, 1917, 1906?, 1897, 1895, 1888, 1871, 1090, 1050, 1030

13. Namarunu Volcano • 1.90 N, 36.27 E • summit elevation 817 m • Shield volcano Namarunu is a volcano located in the Great Rift Valley, Kenya Elevation 817 metres (2,680 feet) 817 metres (2,680 feet) Location Kenya Coordinates 1.98° N 36.43° E Type Shield volcano Last eruption Unknown. Namarunu is located south of the Barrier Volcano in northern Kenya. Hot springs are located at the volcano. Namarunu Volcano Eruptions 6550 BC

14. Segererua Volcano • 1.57 N, 37.90 E • Summit elevation 699 m • Pyroclastic cones Segererua volcano is a series of eruption centres located along a 50 km long NE-SW fissure. The volcano is located east of the east African Rift. Segererua Volcano Eruptions; No recent eruptions.

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

15. Paka Volcano • 0.92 N, 36.18 E • summit elevation 1697 m • Shield volcano Paka is a volcano located in the Great Rift Valley, Kenya. Geothermal activity is widespread at Paka. Last eruption 7550 BC ± 1000 years Geothermal activity is present at the summit caldera and northern flank. Paka Volcano Eruptions6050 BC

16. Korosi volcano • 0.77 N, 36.12 E • summit elevation 1446 m • Shield volcano Korosi is a volcano located at the northern end of Lake Baringo, Kenya. Korosi volcano is located at the north end of Lake Baringo. Fumaroles and hot steaming ground are present at the summit cones and NW flank. Korosi Volcano EruptionsNo recent eruptions.

17. Ol Kokwe Volcano • 0.63 N, 36.08 E • summit elevation 1130 m • Shield volcano Ol Kokwe Island is located in the centre of Lake Baringo. It is the smallest volcano in the northern Rift Valley. Geothermal activity is present along the NE peninsula. Ol Kokwe Volcano Eruptions No recent eruptions.

18. Nyambeni Hills Volcano • 0.23 N, 37.87 E • summit elevation 750 m • Shield volcano • Basaltic cinder cones are the most recent features of the volcano. • No recent eruptions. Meru is located on the Kathita River, on the northeast slopes of Mount Kenya. It is situated about five miles north of the equator, at approximately 1524 meters altitude, in an area of mixed forest and clearings, small towns, villages, and rural farms, and is mainly populated by people of the Meru Tribe. The town is accessible by paved road, whether from the south around the east side of Mount Kenya, via Embu, or from the northwest around the west and north side of Mount Kenya, via Nanyuki and Timau (As of February 2004, the road to Meru via Nanyuki was still fairly

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

rough). Meru District is a jumping-off place for Samburu and Buffalo Springs National Reserves and Lewa Downs, all some distance north of Meru, with Samburu and Buffalo Springs via Isiolo, and Meru National Park, to the northeast of Meru, via Maua in the Nyambeni Hills.

19. Menengai Volcano • 0.20 S, 36.07 E • summit elevation 2278 m • Shield volcano • Menengai Volcano Eruptions 7350 BC Menengai is a massive shield volcano located in the Great Rift Valley, Kenya. Farmland occupies the flanks of the volcano. Menengai is located ten kilometres north of Nakuru, the fourth largest city in Kenya. Menengai volcano is located on the floor of the Rift Valley. It is one of five recent volcanoes in the central Kenya Rift valley. The volcano was formed about 200,000 years ago with the growth of a 30 cubic km volume lava shield. The 12 x 8 km caldera formed 8000 years ago. More than 70 post caldera lava flows cover the caldera floor. Cinder cones are rare at the volcano. The south and western portions of the crater are complete. In the centre of the caldera there is a small cone rising above surrounding lava, which shows fumarolic activity. There have been four fumaroles measured with temperatures up to 94 deg C.

20. Emuruangogolak Volcano • • • •

1.50 N, 36.33 E summit elevation 1328 m Shield volcano Emuruangogolak Volcano Eruptions 1910, 1700, 1300, 1230, 1160, 1115, 6550 BC, 8050 BC Emuruangogolak is a shield volcano straddling the Gregory Rift in Kenya, a country in Eastern Africa. The Global Volcanism Program states that is last known eruption was in 1910 +/- 50 years. The volcano's summit is 1328 m (4357 feet), and its formation is calculated to have been 38,000 years ago.. The volcano is located at the narrowest part of the Baringo-Suguta trough. Volcanic activity commenced about one million years ago. Hot ground and fumaroles are located along fissures within the caldera and lower NW flanks.

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

21. Silali Volcano • 1.15 N, 36.23 E • summit elevation 1528 m • Shield volcano Silali volcano contains a spectacular 8 x 5 km diameter summit caldera which formed 63,000 years ago. Undated young looking lava flows are located on northern and NE flanks. Geothermal activity is present in the caldera and upper eastern flanks. The steep caldera walls are up to 300 m high. Some undated eruptions may be as recent as a few hundred years ago.

22. Homa Mountain • Elevation 1,751 metres (5,745 feet) • Location Kenya Coordinates 0.38° S 34.50° E • Type Complex volcano Last eruption Unknown • 0.38 S, 34.50 E • summit elevation 1751 m • Complex volcano • Homa Mountain Volcano Eruptions: Hot springs are present at the volcano. Mount Homa is a mountain and extinct volcano located in western Kenya. It forms a broad peninsula on the southern shore of Winam Gulf, an extension of Lake Victoria. This peninsula defines Homa Bay and the mountaintop is about 20 kilometres north of the town of that name. In the Luo language Got Uma or Got Marahuma means "famous mountain". The mountain is formed of carbonatite lava and dates from Miocene to Pleistocene. Along with the active Ol Doinyo Lengai, it is one of the very few carbonatite volcanoes in the world. Homa Mountain is located on the eastern shore of Lake Victoria. The volcanic complex consists of the largest centre Homa two other centres Nyasanja and Apoyo. The most recent vents are Chiewo, Got Ojawa and Got Oloo. Other eruptive centres are Rapogi, Nyamatoto, Ratieng, Odiawo, Rongo, and Ndiru. The volcano centre lies in a weakened zone near the intersection of the Kendu and Samaga faults. There is an elliptical lake (Simbi) located east of Homa mountain which probably formed in historical times.

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

Homa Mountain in Kenya 1994

Mount Homa, on Lake Victoria, Kenya December 2001

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

23. Elmenteita Badlands Volcano • 0.52 S, 36.27 E • summit elevation 2126 m • Pyroclastic cones The volcano is located between Lake Elmenteita and Eburru volcano. Elmenteita Badlands Volcano Eruptions No recent eruptions.

24. Ol Doinyo Eburru Volcano • • • •

0.63 S, 36.23 E summit elevation 2856 m Complex volcano Ol Doinyo Eburru Volcano Eruptions; There have been no recorded eruptions during historical times Eburru is a village in Kenya. It is located approximately 3 hours outside capital Nairobi. Eburru is found in Kenya's countryside along the Great Rift Valley. In Kenya Eburru is sometimes referred to as "the bush." It is located neat the Ol Doinyo Eburru volcano. Eburru is home to Primary and Secondary Schools. The volcano is located in one of the least stable parts of the Kenyan Rift Valley. There are numerous steam jets, fumaroles, and solfatara along recent faults.

25. There h Olkaria Volcano (Olkaria) • 0.904 S, 36.292 E • summit elevation 2434 m • Pumice cones • Olkaria Volcano Eruptions 1770 The volcano is located south of Lake Naivasha. Fumarolic activity is present at Njorowa Gorge and two pumice cones. Have been no recorded eruptions during historical times.

26. Suswa Volcano (Ol Doinyo Nyukie) • • • •

1.175 S, 36.35 E summit elevation 2356 m Shield volcano Suswa Volcano Eruptions; Current activity at the volcano consists of fumarolic activity along fracture lines. Mount Suswa is a low-lying Quaternary volcano in the Eastern Rift Valley of Kenya. It rises from the south-sloping floor of the Rift as an asymmetric, shield-shaped cone that covers an area of about 270 km2. The volcano consists of sodalite-bearing, phonolitic lava flows and subordinate proportions of pyroclastic rocks. The cone was built on a volcanic plateau

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composed of quartz-bearing, trachyte flood lavas (Plateau Trachyte Series; Baker 1958). The volcanic history of Mount Suswa can be divided into three major eruptive episodes: (1) formation of a primitive, shield-shaped volcano composed mainly of lava flows derived from central sources; (2) eruptions at the time of cauldron subsidence producing abundant pumice and thick lava flows, most of which issued from a ring-fracture zone outside, and concentric with, the caldera escarpment ('ring-feeder' lavas); (3) post-caldera lavas which partly filled the caldera and later built Ol Doinyo Nyukie volcano. Towards the end of the last eruptive episode an unusual collapse feature, in the form of a 'ring graben', was formed inside the older caldera. South of Mount Suswa a series of north-south linear faults transect the plateau basement of trachyte flood lavas. Near the southern periphery of Mount Suswa these faults die out, in some cases converging toward the centre of the volcano. Also in the south it is not always possible to distinguish between the quartz-bearing, trachyte flood lavas of the Rift floor and the sodalite-bearing flows from the central vents of Mount Suswa. (Sodalitebearing flood lavas are known to be present.) The primitive volcano consists of lava flows, the earliest of which are the most voluminous. An unusual heterogeneous rock comprises the upper parts of the youngest primitive volcano flows. The rock consists principally of globules of lava moulded on to each other, each with a continuous glassy rim and a vesicular, crystalline core. The flows have been termed 'globule-surface lavas' (Johnson 1968). Other heterogeneous glassy rocks on Mount Suswa resemble examples from the controversial 'froth flows' described from various parts of Kenya (including Mount Suswa) by McCall (1965) and McCall Bristow (1965). After a period of quiescence, a caldera was formed in the summit of the primitive volcano. The relationships between the caldera escarpment and the pumice and ring-feeder lavas on Mount Suswa are described in detail. These relationships are significant because they question the widely held assumption that, in calderas with thick pumice mantles, it is the rapid expulsion of pumice (producing a void in the magma chamber) that leads to the collapse of the magma chamber roof. This process, known widely as the 'Krakataun' mechanism (Williams 1941; after van Bemmelen 1929), is not applicable to Mount Suswa since the pumice and ring-feeder lavas mantle the caldera escarpment. Instead, as previously suggested by McCall (1963), a more likely process is that releases of pressure along the ring faults, formed during cauldron collapse, produce the explosive eruptions. In reviewing and discussing in detail the literature on calderas, it is concluded that many so-called 'Krakatau-type' calderas may have originated in the same way as the Mount Suswa caldera. Furthermore, it is emphasized that in the case of any one caldera great care must be taken in describing and interpreting the often ambiguous relations between cauldron subsidence and concomitant explosive eruptions. The post-caldera sequence of lavas on Mount Suswa is divided into two parts: an earlier group of generally non-porphyritic lavas; and a later group of distinctive, porphyritic lavas containing abundant anorthoclase phenocrysts. Most of the flows of the later group were erupted from a central vent in the southwest part of the caldera. They produced Ol Doinyo Nyukie volcano, at the summit of which is a pit crater. The second major collapse on Mount Suswa took place entirely within the older caldera and produced an annular trench, or 'ring graben'. This unusual structure consists of two, more or less concentric, fault scarps bounding a steep-sided annular zone of subsidence. The ring graben truncates the pit crater of Ol Doinyo Nyukie and isolates a tilted, flat-topped, central island-block with a maximum diameter of 3.75 km. The island-block is inaccessible and its detailed structure is unknown. Consequently, the origin of the ring graben is still uncertain. However, three possible subsidence mechanisms are suggested. A

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

fresh lava flow, similar to those of Ol Doinyo Nyukie volcano, partly covers the floor of the ring graben. This flow, and a similar one on the south flank of Mount Suswa, is the most recent eruptions of the volcano. Fumarolic activity persists at the present day. Summary Suswa is a shield volcano in the Great Rift Valley, Kenya. It is located between Narok and Nairobi, the capital of Kenya. Suswa has a unique double crater with a moat-like inner crater surrounding a tilted block of rock. The mountain is also known for its lava tube caves on the northeast side of the outer crater. It is also possible to climb the mountain on foot from the Suswa Primary school at the base of the mountain. Suswa is the southern most caldera in the Kenyan Rift Valley. There is a 12 x 8 km caldera with the rim at an altitude of 1890 m.The volcano contains an unusual island-block abd caldera structure which is also seen at Poseidonius and Gassendi craters on the moon. Eruptions at the volcano are divided into three periods. 1) Initial eruptions formed a shield volcano with an oval outline and covering 337 sq kilometer. Lava flows were viscous and sluggish. The main eruptive phase was followed by eruptions from several small cones distant from the main volcano. 2) After a period of quiet of unknown duration (probably several hundred thousand years) there was a second eruptive phase at the volcano. The eruption centre moved SW along a fracture line and formed a second cone called Ol Doinyo Nyukie. This cone had an asymmetrical shape and a ventral vent which visible as a partly preserved pit crater. 3) The most recent sequence of eruptions at the volcano was the least significant in size.

27. Chyulu Hills Volcano • • • •

2.68 S, 37.88 E summit elevation 2188 m Volcanic field Chyulu Hills Volcano Eruptions; Shaitani and Chainu cinder cones erupted in the mid 1855. Chyulu Hills are located more than 100 km east of the Kenya Rift, and extent for 150 km NW-SE. Eruptions at this off-rift volcano are due to a small mantle plume deflected off the main larger plume under the Rift Valley. This same type of activity is also responsible for eruptions at Kilimanjaro, Mt Kenya, Marsabit, Nyambeni, and Huri Hills. Chyulu volcanic province covers an area of 2840 sq km.Leviathan Lava Tube

Additional East Africa unique volcanic mountains 1. Ol Doinyo Lengai (Tanzania) Ol Doinyo Lengai is a volcano located in the north of Tanzania and is part of the volcanic system of the Great Rift Valley in Eastern Africa. It is located in the eastern Rift Valley, south of both Lake Natron and Kenya. It is unique among active volcanoes in that it

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

produces natrocarbonatite lava, a unique occurrence of volcanic carbonatite, which means its lava is only 510 degrees Celcius (or 950 degrees Fahrenheit). A few older extinct carbonatite volcanoes are located nearby, including Homa Mountain. Whereas most lavas are rich in silicate minerals, the lava of Ol Doinyo Lengai is rich in the rare sodium and potassium carbonates, nyerereite and gregoryite. Due to this unusual composition, the lava is erupted at relatively low temperatures (approximately 500-600 degrees Celsius). This temperature is so low that the molten lava appears black in sunlight, rather than having the red glow common to most lavas. It is also much more fluid than silicate lavas. The sodium and potassium carbonate minerals of the lavas formed by Ol Doinyo Lengai are unstable at the Earth's surface and susceptible to rapid weathering, quickly turning from black to grey in color. The resulting volcanic landscape is different from any other in the world. The chemical makeup of the lava has been compared to dish soap. "Ol Doinyo Lengai" means "Mountain of God" in the language of the native Maasai people. The record of constant eruptions in the mountain goes way back to 1883, and that similar flows were recorded between 1904 and 1910 and again between 1913 and 1915. A major eruption took place in June 1917, which resulted in volcanic ash being deposited about 48 kilometres away. A similar eruption took place for several months in 1926 and between July and December of 1940, resulting in the ash being deposited as far as Loliondo, which is 100 kilometres away. Several minor eruptions of lava were observed in 1954, 1955, 1958 the early 1960s. In modern times, Ol donyo Lengai erupted on August 14, 1966. Two geologists — J B Dawson and G C Clark — who visited the crater a week later, reported seeing “a thick column of black ash” that rose for approximately 915 meters above the volcano and drifted away northwards towards Lake Natron. When the two climbed the cone-shaped vent, they reported seeing a continuous discharge of gas and whitish-grey ash and dust from the centre of the pit. Volcanic activity in the mountain has caused daily earth tremors in Kenya and Tanzania beginning on the July 12, 2007. The latest to hit parts of Nairobi city was recorded on July 18, 2007 at 8.30pm (Kenyan Time). The strongest tremor has measured 6.0 on the Richter scale. Geologists suspect that the sudden increase of tremors is indicative of the movement of magma through the Ol Doinyo Lengai. The volcano finally erupted on September 4, 2007, sending a plume of ash and steam at least 18 kilometers downwind and covering the north and west flanks in fresh lava flows. The eruption has continued intermittently into 2008, as of the end of February it was reported that the eruption appeared to be gathering strength, with a major outburst taking place on March 5. During April periods of inactivity have been followed by eruptions on April 8 and 17, 2008.

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

The flank of the volcano.Ol Doinyo Lengai eruption 1966 Image of 1966 eruption Elevation 2,960 m (9,711 ft) Location Tanzania Coordinates 2°45′5″S, 35°54′8″E Type Stratovolcano Last eruption 2008 (ongoing)[1][2] Easiest route Scramble.

Ol Doinyo Lengai Crater, Tanzania. Taken from south-western edge, showing recent lava flow. 15th August, 2007

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

A view of the flank of the Ol Doinyo Lengai stratovolcano in Africa's Great Rift Valley, specifically in Tanzania, which is often called the world's strangest volcano. Viewed on April 28, 2008 2. Mount Meru (Tanzania) • • •

Elevation4,566 metres (14,980 ft) Location;Arusha Region, Tanzania Coordinates 3°14′S 36°45′E / -3.233, 36.75Coordinates: 3°14′S 36°45′E / -3.233, 36.75 • Type; Stratovolcano • Last eruption1910 Mount Meru is an active volcano located 70 kilometres (44 miles) west of Mount Kilimanjaro. At a height of 4,566 metres (14,980 ft), it is still visible from Mt Kilimanjaro on a clear day. Much of its bulk was lost about 8,000 years ago due to an eastward volcanic blast, similar to the 1980 eruption of Mount St. Helens in the U.S. state of Washington. Mount Meru most recently had a minor eruption about a century ago. The several small cones and craters seen in the vicinity probably reflect numerous episodes of volcanic activity. Mount Meru's ash cone that has formed in the old crater. Mount Meru is the topographic centerpiece of Arusha National Park. Its fertile slopes rise above the surrounding savanna and support a forest that hosts diverse wildlife, including nearly 400 species of birds, and also monkeys and leopards. At the summit, one can find a two metre high flag of Tanzania in metal and also a milestone in concrete with "Socialist Peak 4562.13M" written.

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ACTIVE AND EXTINCT VOLCANOES IN KENYA.

Mount Meru, October 2002

Mount Meru‘s ahs cone that has formed in the old crater

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