1.
Rift zone
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For example, in the currently ongoing eruption of Kilauea in Hawaii, lava is emitted continuously from the Puʻu ʻŌʻō vent located in Kilaueas East Rift Zone roughly 15 km east of Kilauea Crater. Rift zones tend to extend for tens of kilometers radially outward from the volcanic summit, the accumulated lava of repeated eruptions from rift zones causes these volcanoes to have an elongated shape. Perhaps the best example of this is Mauna Loa, which in Hawaiian means long mountain, the origin of the fractures that comprise the rift zones is the spreading of the volcano. The more material a shield volcano accumulates, the heavier it gets and these systems of fissures that make up a rift zone allow this to happen more easily. Hawaii, Most Hawaiian volcanoes have two or sometimes three rift zones
2.
East African Rift
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The East African Rift is an active continental rift zone in East Africa. The EAR 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. As extension continues, lithospheric rupture will occur within 10 million years, the Somalian plate will break off, a series of distinct rift basins, the East African Rift System extends over thousands of kilometers. The EAR 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 includes the Albertine Rift, and farther south, to the north of the Afar Triple Junction, the rift follows one of two paths, west to the Red Sea Rift or east to the Aden Ridge in the Gulf of Aden. The EAR runs from the Afar Triple Junction in the Afar Triangle of Ethiopia through eastern Africa, the EAR transects through Ethiopia, Kenya, Uganda, Rwanda, Burundi, Zambia, Tanzania, Malawi and Mozambique. The Davie Ridge ranges between 30–120 km wide, with a west facing scarp along the half of its length that rises up to 2300 m above the sea floor. Its movement is concurrent with the EAR, over time, many theories have tried to clarify the evolution of the East African Rift. In 1972 it was proposed that the EAR was not caused by tectonic activity, others proposed an African superplume causing mantle deformation. However, the varying geochemical signatures of a suite of Ethiopian lavas suggest multiple plume sources, at least one of deep mantle origin, additionally, the subject of deep-rooted mantle plumes is still a matter of controversy, and therefore cannot be confirmed. The most recent and accepted view is the theory put forth in 2009, at that time it was suggested that lithospheric thinning generated volcanic activity, further increasing the magmatic processes at play such as intrusions and numerous small plumes. These processes further thin the lithosphere in saturated areas, forcing the thinning lithosphere to behave like a mid-ocean ridge, prior to rifting, enormous continental flood basalts erupted on the surface and uplift of the Ethiopian, Somalian, and East African plateaus occurred. The first stage of rifting of the EAR is characterized by rift localization, periods of extension alternated with times of relative inactivity. There was also the reactivation of a weakness in the crust, a suture zone of multiple cratons, displacement along large boundary faults. The second stage of rifting is characterized by the deactivation of large boundary faults, the development of internal fault segments, today, the narrow rift segments of the East African Rift system form zones of localized strain. These rifts are the result of the actions of numerous faults which are typical of all tectonic rift zones. The African continental crust is generally cool and strong, many cratons are found throughout the EAR, such as the Tanzania and Kaapvaal cratons. The cratons are thick, and have survived for billions of years with little tectonic activity and they are characterized by greenstone belts, tonalites, and other high-grade metamorphic lithologies
3.
Lake Mweru
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Lake Mweru is a freshwater lake on the longest arm of Africas second-longest river, the Congo. Located on the border between Zambia and Democratic Republic of the Congo, it makes up 110 km of the length of the Congo. Mweru means lake in a number of Bantu languages, so it is referred to as just Mweru. Mweru is mainly fed by the Luapula River, which comes in through swamps from the south, at its north end the lake is drained by the Luvua River, which flows in a northwesterly direction to join the Lualaba River and thence to the Congo. It is the second-largest lake in the Congos drainage basin and is located 150 km west of the end of the largest. The Luapula forms a swampy delta almost as wide as the end of the lake. In a number of respects the lower river and lake can be treated as one entity, for a lake in a region with pronounced wet and dry seasons, Mweru does not change much in level and area. The annual fluctuation in level is 1. 7m, with highs in May. A rise in Mweru is quickly offset by a faster flow down the Luvua, Mwerus average length is 118 km and its average width is 45 km, with its long axis oriented northeast-southwest. Its elevation is 917 m, quite a bit higher than Tanganyika and it is a rift valley lake lying in the Lake Mweru-Luapula graben, which is a branch of the East African Rift. Mweru is shallow in the south and deeper in the north, with two depressions in the section with maximum depths of 20 m and 27 m. A smaller very marshy lake called Mweru Wantipa lies about 50 km to its east and it is mostly endorheic and actually takes water from the Kalungwishi through a dambo most of the time, but in times of high flood it may overflow into the Kalungwishi and Lake Mweru. The lake was known to Arab and Swahili traders who used Kilwa Island on the lake as a base at one time. They used trade routes from Zanzibar on the Indian Ocean to Ujiji on Lake Tanganyika to Mweru and then to the Lunda, Luba, Yeke or Kazembe kingdoms, western trade routes went from those kingdoms to the Atlantic, so Mweru lay on a transcontinental trade route. The Portuguese must have known of the lake, and the visitors only had to walk to higher ground about 5 km north of Kazembes Kanyembo capital to see the lake 10 km distant. However they were interested in trade routes than discovery, they had approached from the south and their movements were restricted by Mwata Kazembe. Explorer and missionary David Livingstone, who referred to it as Moero, is credited with its discovery during his travels of 1867-8. Livingstone witnessed the devastation and suffering caused by the trade in the area to the north and east of Mweru
4.
Lake Tanganyika
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Lake Tanganyika is an African Great Lake. It is the second oldest freshwater lake in the world, second largest by volume, the lake is divided among four countries – Tanzania, Democratic Republic of the Congo, Burundi, and Zambia, with Tanzania and DRC possessing the majority of the lake. The water flows into the Congo River system and ultimately into the Atlantic Ocean, the name apparently refers to Tanganika, the great lake spreading out like a plain, or plain-like lake. Lake Tanganyika is situated within the Albertine Rift, the branch of the East African Rift. It is the largest rift lake in Africa and the second largest lake by volume in the world and it is the deepest lake in Africa and holds the greatest volume of fresh water, accounting for 18% of the worlds available fresh water. It extends for 676 km in a general direction and averages 50 km in width. The lake covers 32,900 km2, with a shoreline of 1,828 km, a depth of 570 m. It holds an estimated 18,900 cubic kilometres and this is equivalent to about 16% of all fresh water on Earth. The catchment area of the lake is 231,000 km2, two main rivers flow into the lake, as well as numerous smaller rivers and streams. There is one major outflow, the Lukuga River, which empties into the Congo River drainage, the major river flowing into the lake is the Ruzizi River, formed about 10,000 years ago, which enters the north of the lake from Lake Kivu. The Malagarasi River, which is Tanzanias second largest river, enters the east side of Lake Tanganyika, the Malagarasi is older than Lake Tanganyika and, before the lake was formed, directly drained into the Congo River. Apparently it has rarely in the past had an outflow to the sea and it has been described as practically endorheic for this reason. The lakes connection to the sea is dependent on a water level allowing water to overflow out of the lake through the Lukunga into the Congo. Due to the tropical location, it has a high rate of evaporation. Thus it depends on a high inflow through the Ruzizi out of Lake Kivu to keep the lake high enough to overflow. Signs of ancient shorelines indicate that at times Tanganyika may have been up to 300 m lower than its present surface level, even its current outlet is intermittent and may not have been operating when first visited by Western explorers in 1858. Lake Tanganyika is an ancient lake and its three basins, which in periods with much lower water levels were separate lakes, are of different ages. The central began to form 9—12 million years ago, the northern 7—8 mya, there are several islands in Lake Tanganyika
5.
Lake Rukwa
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Lake Rukwa is an endorheic lake in the Rukwa Valley of southwestern Tanzania. The alkaline Lake Rukwa lies midway between Lake Tanganyika and Lake Nyasa at an elevation of about 800 metres, in a branch of the rift system. Almost half of the lies in Uwanda Game Reserve. The lake has seen large fluctuations in its size over the years, currently it is about 180 kilometres long and averages about 32 kilometres wide, making it about 5,760 square kilometres in size. In 1929 it was only about 48 kilometres long, but in 1939 it was about 128 kilometres long and 40 kilometres wide. The lake may at times have been higher and linked Lake Tanganyika with Lake Malawi, ancient shorelines suggest a final date of overflow into Tanganyika of 33. In 2016, an estimated 1.53 billion cubic meters volume of Helium Gas was discovered in Lake Rukwa worth $3.5 billion
6.
Quilotoa
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Quilotoa is a water-filled caldera and the most western volcano in the Ecuadorian Andes. This last eruption followed a period of 14,000 years and is known as the 1280 Plinian eruption. The fourth eruptive phase was phreatomagmatic, indicating that a Crater lake was present at that time. The caldera has since accumulated a 250 m deep crater lake, fumaroles are found on the lake floor and hot springs occur on the eastern flank of the volcano. Quilotoa is a tourist site of growing popularity, the route to the summit is generally traveled by hired truck or bus from the town of Zumbahua 17 km to the South, or more commonly by bus from Latacunga. Visitors may have to pay two US dollars each to look from the lip of the caldera, there are a number of simple hostels in the immediate area offering services such as mules and guides. Activities include a four to five-hour hike around the caldera, the caldera rim is highly irregular and reaches its maximum elevations at three lava domes. The 10 km hike is sandy and steep in places and can be quite taxing and its a half-hour hike down from the viewpoint, and very basic lodging down in its bowl. Camping is permitted at the bottom of the crater, but there is no potable water, the lake surface is located at 3,500 m asl. The total volume of water stored in Lake Quilotoa is 0.35 km3, according to local inhabitants, the lake level has been slowly declining over the last 10 years. Travertine deposits occur along the shore up to 10 m above the lake level, Travel information Travel information Jan 2009 Updated travel info Events in Quilotoa
7.
Ecuador
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Ecuador also includes the Galápagos Islands in the Pacific, about 1,000 kilometres west of the mainland. What is now Ecuador was home to a variety of Amerindian groups that were incorporated into the Inca Empire during the 15th century. The territory was colonized by Spain during the 16th century, achieving independence in 1820 as part of Gran Colombia, Spanish is the official language and is spoken by a majority of the population, though 13 Amerindian languages are also recognized, including Quichua and Shuar. The capital city is Quito, while the largest city is Guayaquil, in reflection of the countrys rich cultural heritage, the historical center of Quito was declared a UNESCO World Heritage Site in 1978. Cuenca, the third-largest city, was declared a World Heritage Site in 1999 as an outstanding example of a planned. Ecuador has an economy that is highly dependent on commodities, namely petroleum. The country is classified as a medium-income country, Ecuador is a democratic presidential republic. The new constitution of 2008 is the first in the world to recognize legally enforceable Rights of Nature, Ecuador is also known for its rich ecology, hosting many endemic plants and animals, such as those of the Galápagos Islands. It is one of 17 megadiverse countries in the world, various peoples had settled in the area of the future Ecuador before the arrival of the Incas. They developed different languages while emerging as unique ethnic groups, even though their languages were unrelated, these groups developed similar groups of cultures, each based in different environments. Over time these groups began to interact and intermingle with each other so that groups of families in one area became one community or tribe, with a similar language and culture. Many civilizations arose in Ecuador, such as the Valdivia Culture and Machalilla Culture on the coast, the Quitus, each civilization developed its own distinctive architecture, pottery, and religious interests. Eventually, through wars and marriage alliances of their leaders, a group of nations formed confederations, one region consolidated under a confederation called the Shyris, which exercised organized trading and bartering between the different regions. Its political and military came under the rule of the Duchicela blood-line. The native confederations that gave them the most problems were deported to distant areas of Peru, Bolivia, similarly, a number of loyal Inca subjects from Peru and Bolivia were brought to Ecuador to prevent rebellion. Thus, the region of highland Ecuador became part of the Inca Empire in 1463 sharing the same language, in contrast, when the Incas made incursions into coastal Ecuador and the eastern Amazon jungles of Ecuador, they found both the environment and indigenous people more hostile. Moreover, when the Incas tried to subdue them, these indigenous people withdrew to the interior, as a result, Inca expansion into the Amazon basin and the Pacific coast of Ecuador was hampered. The indigenous people of the Amazon jungle and coastal Ecuador remained relatively autonomous until the Spanish soldiers, the Amazonian people and the Cayapas of Coastal Ecuador were the only groups to resist Inca and Spanish domination, maintaining their language and culture well into the 21st century
8.
Ottawa-Bonnechere Graben
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The Ottawa-Bonnechere Graben is a seismically active structure that coincides with a 55 km wide topographic depression extending from near Montréal through Ottawa. It is part of the St. Lawrence rift system also includes the seismically active Saguenay graben. This rift valley was formed when the Earths crust moved downward about a kilometre between two major fault zones known as the Mattawa and Petawawa faults. These ancient faults are still active and occasionally release stress in the form of earthquakes, such as the 1935 Timiskaming earthquake, the length of the graben is about 700 km. The Ottawa-Bonnechere Graben runs from the Montreal area on the east to near Sudbury, on the east, it joins the Saint Lawrence rift system, a half-graben which extends more than 1000 km along the Saint Lawrence River valley and links the Ottawa and Saguenay Graben. The 200 km segment of the Ottawa-Bonnechere Graben west of Ottawa was the first to be recognized as a graben and this latter branch is the Timiskaming Graben. At the rifts western termini, the main faults split into divergent smaller faults, the graben has been interpreted as a Late Proterozoic to Early Paleozoic failed arm of the Iapetus Ocean, the precursor to the Atlantic Ocean. These graben were reactivated during the breakup of supercontinent Pangaea some 150 mya, since the Late Proterozoic to Early Paleozoic, erosion has removed the volcanic peaks, exposing a number of relic volcanic pipes, such as Callander Bay and the Manitou Islands in Lake Nipissing. These features are subterranean geological structures formed by the violent, supersonic eruption of deep-origin volcanoes, batholiths and dikes were also exposed by erosion, such as the Timber Lake, Mulock, West Arm, Powassan and Bonfield batholiths. The precise age of these volcanics is unknown but they are either early Cambrian and this volcanism was probably coeval with the emplacement of the Grenville dike swarm. This second episode of alkalic volcanism occurred along the part of the graben in the early Cretaceous. The products of this event are the Monteregian Hills in Montérégie, of all these features, Mont Saint-Hilaire is the best known as a source of rare specimens. Along the northern side of the Ottawa-Bonnechere Graben lies a dramatic escarpment that forms the edge of the Gatineau Hills. On or near a branch of the Ottawa-Bonnechere Graben lies the Brent impact crater and it is 3.8 km in diameter and the age is estimated about 400 million years. The impact crater, which was first recognized in 1951 from aerial photographs, geophysical and diamond drilling investigations show that the crater has a present depth of about 425 m but is partly filled with sedimentary rocks with a thickness of about 274 m. The rocks beneath the floor are thoroughly fragmented over a depth of about 610 m. Like the similar Pingualuit crater, the Brent crater is attributed to the high speed impact of a giant meteorite and it is calculated that the impact released energy equaling 250 megatons of TNT and occurred when this area was probably covered by a shallow sea. The depressions formed by the graben across the rugged Canadian Shield were a spillway for the Great Lakes after the last Ice Age, later they became a thoroughfare for exploration and trade
