The word Virunga comes from a Kinyarwanda dialect ‘Ibirunga’ meaning volcanoes in English. The Virunga Mountains are a chain of 8 volcanoes located in East-Central Africa along the borders of Rwanda, Uganda, and the DR Congo.
Size of the Virunga Mountains
The ranges extend for about 80 km (50 miles) north of Lake Kivu perpendicular to the East African Rift Valley. The 8 Virunga mountains from highest to lowest include Mt. Karisimbi 4,507 meters (14,790 ft), Mt. Mikeno 4,437 meters (14,560 ft), Mt. Muhabura 4,127 meters (13,540ft), Mt. Bisoke 3,711 meters (12,180ft), Mt. Sabinyo 3,674 meters (12,050ft), Mt. Mount Gahinga 3,474 meters (11,400ft), Mount Nyiragongo 3,470 meters (11,400ft), and Mt. Nyamuragira 3,058 meters (10,031ft).
History of volcanicity of the Virunga Mountains
According to Britannica, volcanic activity in the Virunga region began in the early part of the Pleistocene Epoch about 2,600,000 million years ago. In other words, the Virungas are actually Pleistocene volcanoes. Mikeno and Sabinyo volcanoes are the oldest natural wonders and are considered to be extinct.
The volcanoes of Bisoke, Muhavura, Karisimbi, and Gahinga were formed during the later Pleistocene era about 900,000 to 130,000 years ago, making them relatively younger. At least 7 Virunga volcanoes except Mount Nyamuragira (shield volcano) are composite volcanoes formed by repeated volcanic eruptions that deposit layers of pyroclastic lava, ash and mud that buildup over a long period of time.
Composite volcanic landforms have a conical shape, relatively steep slopes, and massive bowl-shaped volcanic depression known as a caldera such as the one on Mount Karisimbi. The craters on Mount Bisoke, Gahinga, and Muhabura contain water, making for a must-visit gem in East Africa. Due to the nature of terrain, composite volcanoes are also vulnerable to the processes of weathering and erosion.
For instance, Mount Sabinyo has been severely degraded and its jagged peak resembles an ‘old man’s teeth,’ a nickname from the Bakiga of southwest Uganda. The Virunga volcanoes that are dormant include Bisoke, Karisimbi, Muhabura, and Mikeno. Gahinga is considered to be extinct.
Origin of volcanicity in the Virungas
There are two active volcanoes located in the eastern belt in Virunga national park in DR Congo. Among the best known of these volcanoes are Nyamuragira and Nyiragongo which have erupted over 44 and 34 times since 1882 respectively.
Due to the repeated violent volcanic eruptions, the Virunga mountains are more commonly referred to as the Mufumbiro ranges, a Kinyarwanda dialect meaning “that which cooks,” The violent volcanic eruptions have left an active lake lake and several volcanic fissures and cinder cones on each volcano. The two volcanoes are 13 km apart and are separated by a tectonic fault line called Kameronze fault.
According to National Geographic, active volcanic activity in the Virunga results from the tectonic rift known as the East African rift. The East African rift valley is a strip of land that stretches for 3,500 sq.km from Red Sea to Mozambique. It consists of two parallel branches which include the eastern rift (Somalia plate) that passes through Ethiopia and Kenya and the western rift (Nubian plate) from Uganda to Malawi.
According to the Geological Society, the two plates are being pulled apart at a rate of 6-7 mm per year by tectonic forces that started in the Miocene Era about 25 million years ago. The rifting process creates fault lines and cracks where magma rises to the earth’s surface in the form of violent volcanic eruptions such as those on Nyiragongo and Nyamuragira volcanoes. The type of magma erupting out these volcanoes is known as alkaline magma with low silica content, making it highly fluid. Nyiragongo magma can flow at high speeds of up to 100 km per hour and contains high amounts of carbon dioxide.
Hiking in the Virunga Mountains
Hiking in the Virunga mountains is available in the protected areas including Volcanoes, Mgahinga, and Virunga national parks. For instance, Bisoke, Karisimbi, and Muhabura volcanoes can be hiked from Rwanda’s volcanoes national park. Hiking Mt. Sabinyo, Gahinga, and Muhabura is done in Uganda Mgahinga gorilla national park. Nyiragongo volcano trek was closed following the violent volcanic eruption in 2021. Updates will be unveiled once the trail conditions are fit for hiking and security situation is deemed stable Virunga Park is als closed due to open again. However, you can still visit the fresh lava fields around Goma city.
Nyiragongo is the tallest and one of the most active volcanoes in Africa with an elevation of 3,470 meters (11,400ft). It lies within Kibumba, the southern sector of Virunga national park, a UNESCO world heritage site in danger in eastern DR Congo.
The volcano contains a 1.2 km wide lava lake that has been active since 1882 with over 34 recorded eruptions. Some of the recent historical eruptions of Nyiragongo occurred in 1977, 2002, and 2021 respectively were some of the most disastrous in history. Nyiragongo is one of the volcanoes with the most people living nearby. Almost 1 million people reside at the base of the volcano with 700,000 people in the city of Gisenyi in Rwanda and 83,000 people in Goma in the DR Congo.
The two cities are located on the shores of Lake Kivu and 8.0 km apart. In particular, at least 70 people lost their lives during the eruption of January 1977. Given that the natural disasters pose a big threat to the people, the Goma Volcano Observatory (OVG) was established in 1986 to monitor the eruptions through the use of satellite data available at the database of the Global Volcanism Network of the Smithsonian Institute.
This would help to detect warning signs early on to evacuate people and avoid fatalities from further eruptions. In 2002 Nyiragongo ejected 10,000 m³ of highly fluid lava moving downslope at speeds of 60km/hr. The lava flows covered almost 15% of Goma city’s surface and one-third of Goma international airport runway was buried by lava flows. Over 4,500 houses and buildings were destroyed along with the evacuation of 400,000 people.
Most recently, in May 2021 Nyiragongo experienced lateral volcanic eruptions rising from fissures on Murara cone on the southern flank of the volcano leading to displacement of 450,000 people. The lava flows were also associated with strong earthquakes and volcanic air pollution. Emission of carbon dioxide, one of the most harmful greenhouse gasses, led to the loss of 180 lives during the 2002 and 2021 eruptions.
With the magnitude of such damage, the Goma observatories were not able to detect signs except for earthquakes that an eruption would occur. However, some data indicate the reasons why. One of the reasons is that Mt. Nyiragongo volcanic eruptions are associated with the underlying tectonic rifting that is causing more fissures and vents on the flanks of the volcano.
Therefore, the magma easily erupts through the active lava lake that sits atop as well as the fissures. For instance, the historical eruptions of Nyiragongo of 1977, 2002, and 2021 are flank eruptions. Furthermore, scientists speculate that Nyiragongo eruptions are increasingly becoming unpredictably dangerous and could in the future trigger limnic eruptions in Lake Kivu. According to Smithsonian Magazine, seismologists must develop better technology to improve monitoring of future eruptions.
Nyiragongo eruption of 2021
After the Nyiragongo eruption of 2021, hiking Mount Nyiragongo was called off. This was caused by the lava flow that had cut off roads and hotels in the areas of Rumangabu. oweverVisitors can still visit Goma lava fields to truly understand the extent of the eruption. Donations of any kind are accepted to help restore people’s homes and clean water in Goma. You can give through a tour operator or a local humanitarian organization such as the Virunga Fallen Rangers Fund. Another way to support locals and experience their culture is to visit the communities’ villages adjacent to Virunga National Park.
Nyamuragira is a shield volcano located 13 km north west of Mt. Nyiragongo and 25 km north of Lake Kivu in southern Virunga National Park. Nyamuragira lies at the western tip of the Virunga Volcanic Province (VVP) and has erupted for over 44 times since 1882 making it more active than its counterpart Nyiragongo. On average, Nyamuragira eruptions occur at least for every 1 to 4 years.
The summit of Nyamuragira is 3,058 meters (10,031ft) and contains a 2.3 km wide caldera with an active lake surrounded by rift walls of up to 100 meters high. The volcano also has several isolated smaller cinder cones including Gasenyi and Kimanura on the north east flank and Kitazungurwa vent on the southern slope. Eruptions occur from within the lava lake as well from the fissures and cinder cones especially on the south west flank.
Nyamuragira eruptions are characterized by lava fountains and pyroclastic flows due to the high concentration of chemical components like sulfur dioxide and potassium present in the magma. Nyamuragira lava flows are some of the longest in the world. For instance, lava flows from the 1981 eruption traveled for 26 km on the north east flanks. Nyamuragira erupted again in 1989, 2000, and 2014 with lava flow that reached 20 km on the north flank.
Nyamuragira Lava flows have covered over 1,500 sq.km reaching as far as Lake Kivu. Nyamuragira isn’t open for hiking. However, research and study trips are available for those intending to study the volcano.
Mt. Mikeno is a composite volcano situated in Virunga National Park at the western edge of the Virunga volcanic province. With a height of 4,387 m (14,393 ft), Mikeno is the second-tallest peak in the Virunga range.
Having formed during the early Pleistocene age, it is among the oldest volcanoes. Given that no eruption has been seen since, Mikeno is an extinct volcano with steep slopes, lava domes and pyroclastic cones not suitable for human settlement. The name Mikeno means “poor” in the local Congolese dialect.
The volcano is covered by tropical forests that provide home to a plethora of wildlife including mountain gorillas, chimpanzees, colobus monkeys, and bird species such as the yellow-crested helmet shrike (Prionops Alberti). The Virunga Park authorities began to habituate a community of chimpanzees and opened Mikeno trek in 2011.
The trek offers two options with one meant for those intending to reach the summit and the other is a gentle walk on the lower slopes. Hiking to the summit of Mikeno can be challenging due to the nature of terrain. The trek begins at Bukima, the park headquarters next to the luxurious Mikeno lodge.
Mt. Karisimbi is the tallest in the Virunga ranges with an altitude of 4,490 m (14,731 feet). The composite volcano has a symmetrical-shaped peak with extremely steeper slopes of 25-30 gradients.
The volcano lies within Volcanoes national park near the border with DR Congo. The last recorded eruption of Karisimbi was in 8050 BCE and left unique volcanic features including a circular 2 km wide caldera, pit crater, and flat-lying basalt lava fields. The lava fields of Karisimbi volcano stretch for 400 sq.km and are characterized by lava tubes with no watercourses.
Karisimbi is presently a dormant volcano with the highest density of over 106 parasitic spatter and cinder cones. The age of black basalt volcanic rocks present on Karisimbi are 10,000 years old as measured by potassium dating method. Mount Karisimbi is notable for its four vegetation zones including dense tropical forests, bamboo, afro-alpine, and bare volcanic rock surface.
Mt.Bisoke 3,696 m (12,126 feet) is a composite volcano located north of Mount Karisimbi along the border of Rwanda and DR Congo. The peak of Bisoke lies within Rwanda’s Volcanoes national park and is considered to be an active volcano with the last known eruption in 1957.
The eruption emitted Trachyandesite lava flows that formed a summit crater that contains a 450 meters wide crater filled lake. Trachyandesite lava is formed after cooling of volcanic materials containing alkali metals and intermediate silica compounds. The eruptions also formed two smaller parasitic cones on the northern flank about 11 km from the summit. Bisoke is one of the most beautiful volcanoes in the Virunga ranges.
Afroalpine plant species such as groundsels grow around the crater lake. The forested lower slopes are home to golden monkeys and mountain gorillas. It is on the saddle between Bisoke and Karisimbi that Dian Fossey established the Karisoke Research Center in 1967 to study mountain gorillas. Bisoke hike offers an opportunity to visit the Dian Fossey Tomb.
Sabyinyo volcano, the 5th highest in Virunga range, was formed by an explosive eruption during the Pliocene and Pleistocene between 3.2 and 2.6 million years ago, and is the oldest in the Virunga volcanic province.
The last known eruption is thought to have blasted the symmetrical shaped summit creating 5 different peaks that are separated by narrow and deep ridges. The summits were further molded into jagged and steep-sided peaks by extensive erosion. The craggy peaks were nicknamed Sabinyo which translates to “old man’s teeth.” Mt. Sabino’s highest peak stands at an altitude of (3605 m / 11827 ft) with a summit caldera that contains a crater-filled lake.
Of the 5 peaks 3 including the summit are in Uganda’s Mgahinga Gorilla National Park and 2 on the boundary between Rwanda and the DR Congo. Sabinyo is the only volcano in Virunga that is shared between the three countries. The trek in Uganda allows you to stand at the three-country border point. Climbing can be challenging due to the nature of terrain.
The trail involves climbing across wooden ladders that lead up a steep slope between two peaks (3,423 m and 3,537 m) to reach the final summit. Hiking Sabinyo is also done in Rwanda’s Volcanoes national park with two trails to choose from. The Rurambo trail involves hiking to the two summits and is the most challenging.
Sabyinyo trail is the easiest and offers access to the peak on the Volcano’s eastern flank. Mt. Sabinyo is unique in terms of terrain, breathtaking views, and the vegetation on the slopes includes an ever-green hagenia – hypecerum forest with mosses, lichens, and liverworts blanketing the trees and ground floor.
The 3rd tallest volcano in the Virunga range, Muhabura volcano stands at 4,127 meters (13,540ft) with a summit caldera that contains a 40-meter-wide crater-filled lake. The mountain straddles the Uganda and Rwanda border where trekking is permitted. The name Muhabura means a ‘guide’ given that its steep summit can be seen many miles away and the ancient people utilized it for navigation. Due to the nature of terrain, hiking Muhabura can be challenging and is ideal for intermediate hikers who can hike for a whole day.
Mount Gahinga is a dormant volcano and the 6th tallest in the Virunga range with an elevation of 3,474 meters (11,400ft). The volcano lies 4 km east of Muhabura on the Uganda-Rwanda border with a swamp filled-crater lake atop. The northern flank is part of Uganda’s Mgahinga gorilla and the southern side in Rwanda’s Volcanoes national parks. Hiking Sabinyo from the Ugandan side offers an opportunity to visit the Batwa pygmy community through the Batwa trail. There’s also the luxurious Gahinga Lodge tucked on the edge of the park with spectacular views of the surrounding volcanoes.