In chemistry, an alkali is a basic, ionic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The adjective alkaline, and less often, alkalescent, is commonly used in English as a synonym for basic, especially for bases soluble in water. This broad use of the term is likely to have come about because alkalis were the first bases known to obey the Arrhenius definition of a base, and they are still among the most common bases.
Tanzania comprises many lakes, national parks, and Africa's highest point, Mount Kilimanjaro. Northeast Tanzania is mountainous, while the central area is part of a large plateau covered in grasslands. The country also contains the southern portion of Lake Victoria on its northern border with Uganda and Kenya.
Natron is a naturally occurring mixture of sodium carbonate decahydrate (Na2CO3·10H2O, a kind of soda ash) and around 17% sodium bicarbonate (also called baking soda, NaHCO3) along with small quantities of sodium chloride and sodium sulfate. Natron is white to colourless when pure, varying to gray or yellow with impurities. Natron deposits are sometimes found in saline lake beds which arose in arid environments. Throughout history natron has had many practical applications that continue today in the wide range of modern uses of its constituent mineral components.
Sodium carbonate is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, odourless, water-soluble salts that yield alkaline solutions in water. Historically, it was extracted from the ashes of plants grown in sodium-rich soils, and because the ashes of these sodium-rich plants were noticeably different from ashes of wood, sodium carbonate became known as "soda ash". It is produced in large quantities from sodium chloride and limestone by the Solvay process, as well as by carbonating sodium hydroxide which is made using the Chlor-alkali process.
The lesser flamingo is a species of flamingo occurring in sub-Saharan Africa and western India. Birds are occasionally reported from further north, but these are generally considered vagrants.
Lake Bogoria is a saline, alkaline lake that lies in a volcanic region in a half-graben basin south of Lake Baringo, Kenya, a little north of the equator. Lake Bogoria, like Lake Nakuru, Lake Elementeita, and Lake Magadi further south in the Rift Valley, and Lake Logipi to the north, is home at times to one of the world's largest populations of lesser flamingos. The lake is a Ramsar site and Lake Bogoria National Reserve has been a protected National Reserve since November 29, 1973. Lake Bogoria is shallow, and is about 34 km long by 3.5 km wide, with a drainage basin of 700 km2. It is Located in Baringo County.
Lake Magadi is the southernmost lake in the Kenyan Rift Valley, lying in a catchment of faulted volcanic rocks, north of Tanzania's Lake Natron. During the dry season, it is 80% covered by soda and is well known for its wading birds, including flamingos.
The Etosha Pan is a large endorheic salt pan, forming part of the Cuvelai-Etosha Basin in the north of Namibia. It is a vast hollow in the ground in which water may collect or in which a deposit of salt remains after water has evaporated. The 120-kilometre-long (75-mile-long) dry lakebed and its surroundings are protected as Etosha National Park, Namibia's second-largest wildlife park, covering 22,270 square kilometres (8,600 sq mi). The pan is mostly dry but after heavy rains it is flooded with a thin layer of water, which is heavily salted by the mineral deposits on the surface.
Lake Nakuru is one of the Rift Valley lakes, located at an elevation of 1,754 m (5,755 ft) above sea level. It lies to the south of Nakuru, in the rift valley of Kenya and is protected by Lake Nakuru National Park.
Natrocarbonatite is a rare carbonatite lava which erupts from the Ol Doinyo Lengai volcano in Tanzania within the East African Rift of eastern Africa. Natrocarbonatite lavas were first documented in 1962, by J. B. Dawson.
Lake Logipi is a saline, alkaline lake that lies at the northern end of the arid Suguta Valley in the northern Kenya Rift. It is separated from Lake Turkana by the Barrier volcanic complex, a group of young volcanoes that last erupted during the late 19th century or early 20th century. Saline hot springs discharge on the northern shoreline of Lake Logipi and at Cathedral Rocks near its southern limit, and help to maintain water at times of extreme aridity. During the rainy season, the lake is also recharged from the Suguta River which flows northward along the Suguta Valley, periodically forming a temporary lake that unites with Logipi.
Lake Tsimanampetsotsa is a moderately alkaline lake in the Toliara Province, in the southwestern part of Madagascar. It is located at around 24°07′S43°45′E. The lake is protected within Tsimanampetsotsa National Park and it is also within a Ramsar site. The Ramsar site has a total area of 456 km2 (176 sq mi), while the surface of the lake is much smaller.
Larnaca Salt Lake is a complex network of four salt lakes of different sizes to the west of the city of Larnaca. The largest is lake Aliki, followed by lake Orphani, lake Soros and lake Spiro. They form the second largest salt lake in Cyprus after the Limassol Salt Lake. The total surface area of the lakes adds up to 2.2 km2 and being just off the road leading to Larnaca International Airport, the lake is one of the most distinctive landmarks of the area. It is considered one of the most important wetlands of Cyprus and it has been declared a Ramsar site, Natura 2000 site, Special Protected Area under the Barcelona Convention and an Important Bird Area (IBA). It is surrounded by halophytic scrubland and on its bank lies the Hala Sultan Tekke, one of the holiest of shrines within Ottoman Islam. It houses the tomb of Umm Haram, Muhammad's 'wet-nurse'.
The chestnut-banded plover is a species of bird in the family Charadriidae. This species has a large range, being distributed across Southern Africa. However, it occupies a rather small area.
Alcolapia grahami, the Lake Magadi tilapia or Graham's cichlid, is a vulnerable species of fish in the family Cichlidae. It is specialised to live in hot, alkaline waters in springs and lagoons around hypersaline lakes.
A soda lake or alkaline lake is a lake on the strongly alkaline side of neutrality, typically with a pH value between 9 and 12. They are characterized by high concentrations of carbonate salts, typically sodium carbonate, giving rise to their alkalinity. In addition, many soda lakes also contain high concentrations of sodium chloride and other dissolved salts, making them saline or hypersaline lakes as well. High pH and salinity often coincide, because of how soda lakes develop. The resulting hypersaline and highly alkalic soda lakes are considered some of the most extreme aquatic environments on Earth.
The Great Rift Valley is part of an intra-continental ridge system that runs through Kenya from north to south. It is part of the Gregory Rift, the eastern branch of the East African Rift, which starts in Tanzania to the south and continues northward into Ethiopia. It was formed on the "Kenyan Dome" a geographical upwelling created by the interactions of three major tectonics: the Arabian, Nubian, and Somalian plates. In the past, it was seen as part of a "Great Rift Valley" that ran from Madagascar to Syria. Most of the valley falls within the former Rift Valley Province.
The Southern Ewaso Ng'iro is a river in the Great Rift Valley in Kenya. It plays an important role in the ecology of Lake Natron, the main regular breeding site for near-threatened lesser flamingos. Changes to land use in the river's headwaters or in the marshes before the river enters the lake could have a serious impact on this species.
The Saharan halophytics ecoregion covers a series of low-lying evaporite depressions and wetlands spread across North Africa. The depressions are characteristically saline, variously chotts or sabkhas. The plants of the areas are highly specialized to survive in the harsh environment, with many being xerophytes (drought-tolerant) and halophytes (salt-tolerant). The biodiversity of the areas has been relatively protected by their isolation, and unsuitability of alkaline soil for farming.
Lake Pikrolimni is an endorheic, alkaline salt lake in Kilkis prefecture, Greece. It is located on the border of the Kilkis and Thessaloniki regional units, about 40 km northwest of Thessaloniki. The lake is hypersaline, has rather shallow waters (0.5–0.7 m) and a shoreline of about 8.5 km. The water surface area shows significant seasonal variation (3.2–4.5 km2) due to evaporation in the summer months, with an average value of 3.7 km2.
Lake Natron as seen on NASA's World Wind program
The lake with flamingos
Ol Doinyo Lengai seen from Lake Natron
