| Lonar Lake | |
|---|---|
 View of Lonar crater (Buldhana district, Maharashtra) from the rim | |
  Lonar Lake Location in Maharashtra, India | |
| Location | Lonar,Buldhana district,Maharashtra,India |
| Coordinates | 19°58′30″N76°30′27″E / 19.97500°N 76.50750°E /19.97500; 76.50750 |
| Type | impact crater lake,salt lake |
| Basin countries |  India |
| Max. length | 1,830 m (6,000 ft) |
| Surface area | 1.13 km2 (0.44 sq mi) |
| Average depth | 137 m (449 ft) |
| Max. depth | 150 m (490 ft) |
| Water volume | 0.15 km3 (0.036 cu mi) |
| Residence time | IST |
| Surface elevation | 480 m (1,570 ft) |
| Settlements | Lonar, nearBuldhana city |
| References | earthobservatory |
| Designated | 22 July 2020 |
| Reference no. | 2441[1] |
Lonar Lake, also known asLonar crater, is asaline,soda lake, located atLonar, 79 km fromBuldhana city inBuldhana district,Maharashtra,India. It is a notifiedNational Geo-heritage Monument.[2][3][4]
Lonar Lake is in animpact crater created by ameteorite impact during thePleistocene Epoch.[5][6] It is one of only four known hyper-velocity impact craters inbasaltic rock anywhere on Earth. The other three basaltic impact structures are in southernBrazil.[7] Lonar Lake has a mean diameter of 1.2 kilometres (3,900 ft) and is about 137 metres (449 ft) below the crater rim. The meteor crater rim is about 1.8 kilometres (5,900 ft) in diameter.[8]
Although the crater's age was previously estimated to be 52,000 ± 6,000 years,[9] newer studies suggest an age of 576,000 ± 47,000 years.[10][11]
Lonar Crater sits inside theDeccan Plateau – a massive plain of volcanic basalt rock created by eruptions some 65 million years ago. Its location in this basalt field suggested to some geologists that it was a volcanic crater. Today, however, Lonar Crater is understood to be the result of a meteorite impact.[12] The water in the lake is bothsaline andalkaline.
Geologists, ecologists, archaeologists, naturalists and astronomers have published studies on various aspects of the ecosystem of this crater lake.[13]
TheSmithsonian Institution, theUnited States Geological Survey,Geological Survey of India, theUniversity of Sagar and thePhysical Research Laboratory have conducted extensive studies of the site.[14][15] Biologicalnitrogen fixation was discovered in this lake in 2007.[16]
A 2019 study, conducted byIIT Bombay found that the minerals in the lake soil are very similar to the minerals found inMoon rocks brought back during theApollo Program.[17] The lake was declared a protectedRamsar site in November 2020.[18]
A series of small hills surround the basin, which has an oval shape, almost round, with a circumference at top of about 8 km (five miles). The sides of the basin rise abruptly at an angle of about 75°. At the base of the sides, the lake has a circumference of about 4.8 km (three miles). The slopes are covered with tree-savannah, housing teak (Tectona grandis),Wrightia tinctoria,Butea monosperma, andHelicteres isora, and with shrub-savannah housingAcacia nilotica andZiziphus spp.. Along the lake shore, non-nativeProsopis juliflora is spreading.[19]Millet,maize,okra,banana, andpapaya are the main cultivated crops.
The water of the lake contains various salts and sodas. During dry weather, when evaporation reduces the water level, large quantities of soda are collected. Two small streams, named Purna and Penganga,[20] drain into the lake, and a well offresh water is located on the southern side, close to the water's edge.[21]
| Lonar crater | |
|---|---|
  Lonar crater Asteroid impact location in Asia | |
| Impact crater/structure | |
| Confidence | Confirmed |
| Diameter | 1.8 km (1.1 mi) |
| Depth | 290 m (950 ft) |
| Age | 570 ± 47 Ka |
| Country | India |
Lonar Lake lies within the only known extraterrestrial impact crater found within the greatDeccan Traps, a hugebasaltic formation in India.[22] The lake was initially believed to be ofvolcanic origin, but now it is recognized as an impact crater. Lonar Lake was created by the impact of either acomet or of anasteroid. The presence ofplagioclase that has been either converted intomaskelynite or containsplanar deformation features has confirmed the impact origin of this crater. It is believed that onlyshock metamorphism caused by a hypervelocity impact can transform plagioclase into maskelynite, or create planar deformation features. The presence of impact deformation of basalt layers comprising the rim, of shockedbreccia inside the crater, ofshatter cones, and of the non-volcanicejecta blanket surrounding the crater all support the impact origin of Lonar Lake.[citation needed]
The crater has an oval shape. The meteorite impact came from the east, at an angle of 35 to 40 degrees.[23]
There are various estimates of the age of the crater. Earlier thermoluminescence analyses gave a result of 52,000 years, while recentargon-argon dating suggests that the crater is much older; it could be 570 000 ± 47 000 years old. This greater age is in line with the degree of erosion of the crater rim.[24][23]
As a result of the studies, the geological features of the Lonar crater have been divided into five distinguishable zones, exhibiting distinct geomorphic characteristics.[25]The five zones are:[26]
The lake was first mentioned in ancient scriptures such as theSkanda Purana and thePadma Purana.[citation needed]
TheAin-i-Akbari, a document written about 1600 CE, states:
These mountains produce all the requisites for making glass and soap. And here are saltpetre works which yield a considerable revenue to the State, from the duties collected. On these mountains is a spring of salt water, but the water from the centre and the edges is perfectly fresh.[21]
Buldhana district in Maharashtra, where the lake is located, was once part of theMaurya Empire and then part of theSatavahana Empire. TheChalukyas andRashtrakutas also ruled this area. During the period of theMughals,Yadavas,Nizam, and the British, trade prospered in this area. Several temples found on the periphery of the Lake are known asYadava temples and also as Hemadpanti temples (named after Hemadri Ramgaya).
In 2022, the government of Maharashtra began plans to develop the site as a tourist attraction.[27]
There is a small circular depression at a distance of around 700 m (2,300 ft) from the main lake, believed to be caused by a fragment of the main meteor. There is aHanuman temple near this lake, with the idol made of rock believed to be highly magnetic. The water from Ambar lake is being drained by local farmers.[28] This lake is sometimes also calledChhota (little) Lonar.[20]
TheGazetteer chronicles the findings of the British administrators and scientists, notably, Colonel Mackenzie, scientist Dr. I. B. Lyon, J. O. Malcolmson and Plymen, agricultural chemist. Some extracts from Plymen's report, given in quotes, are informative.[29]
The saline deposits obtained from the lake are rather of an exceptional nature. Compared with the most famous salt lake in India, the Sambhar Lake in Rajasthan (India), it will be seen that whereas at Lonar the carbonates of soda are the most important, in the case of the Sambhar Lake the deposits of sodium chloride or common salt give the lake its value. The modes of formation are also entirely different and it is practically certain that the Lonar salts are derived from an unknown source in the bed of the lake. It is true that water is continually flowing into the lake and that except by evaporation there is no loss. The main feeder stream could not however supply this amount of alkali nor could the other smaller supplies coming in during the rains, for on all sides of the lake vegetation is abundant, particularly where the main stream flows in continuously. Were any quantity of alkali present in this water, vegetation would suffer considerably and, with exception of a few varieties of plants, eventually die out entirely.
The salts collected from this lake vary in their nature and composition and from their-appearance are easily separated by men accustomed to handling them. Various names are given to some five or six main varieties, but there is no fixed line between one salt and another, their compositions depending upon the period and condition of crystallization. At the present time large quantities of these salts are lying on the shores of the lake...
With the process of crystallization,sodium chloride or common salt is formed along with the carbonates of soda resulting in a number of products, as explained below.[29]
Kala Namak and Nimak Dalla are found in white crystalline masses.Khuppal is obtained in solid compact lumps and consists of a mixture of carbonates and chlorides in roughly equal proportions.Pipadi orPapri, which has a similar chemical composition, is very different in appearance. It is frequently tinged, slightly pink in colour and hollow air spaces are found between the crystalline masses which are formed in flakes or layers.Bhuski has no definite structure but consists of a soft flaky powder mixed with a quantity of impurity. It can be compared to small salt substance or baking soda.The salts are not all obtained in the same way or at the same period of the year.Pipadi andbhuski are deposited on the shores of the lake as the water dries up in the hot weather,pipadi being the upper layer and therefore the purer. Except forbhuski, the salts are in a fairly pure state and contain only small proportions of earthy matter. Their further purification is not considered difficult.[29]
Commercial exploitation of the salts from the lake is recorded from 1842, including the period of Government of Nizam, and until 1903. Presently, there is only a very small local demand for these Lonar Lake products.[29]
Gaylussite is the mineral has been recently reported from drill core in Lonar lake.[30] Gaylussite is acarbonate mineral, a hydrated sodium calcium carbonate, formula Na2Ca(CO3)2·5H2O. It occurs as translucent, vitreous white to grey to yellowmonoclinic prismatic crystals. It is an unstable mineral which dehydrates in dry air and decomposes in water.[31]
Streptomyces alkalithermotolerans is analkaliphilic andthermotolerant bacterium species from the genus ofStreptomyces which has been isolated from the Lonar soda lake inIndia.[32][33]
The chemical characteristics of the lake shows two distinct regions that do not mix – an outer neutral (pH 7) and an inneralkaline (pH 11) each with its own flora and fauna. The lake is a haven for a wide range of plant and animal life.[34]
The site has 160 bird, 46 reptile and 12 mammal species.[35] Resident andmigratory birds such asblack-winged stilts,brahminy ducks,grebes,shelducks (European migrants),shovelers,teals,herons,red-wattled lapwings, rollers orblue jays,baya weavers,parakeets,hoopoes,larks,tailorbirds,magpies,robins andswallows are found on the lake.[34]
Among reptiles, themonitor lizard is reported to be prominent. The lake is also home to thousands ofpeafowls,chinkara andgazelles.[34] The area of 3.83 km2 (1.48 sq mi) was declared as Lonar Wildlife Sanctuary by the government on 20 November 2015.[36]
While the Lonar Lake appears green for most of the year due to the presence of dense blooms of cyanobacteria such asArthrospira spp.,[37] bacteria and archaea belonging to diverse functional groups such as methanogens, methanotrophs, phototrophs, denitrifiers, sulfur oxidizers, sulfate reducers, heterotrophs and syntrophs have been reported.[38][39][37][40][41][42][43][44][45][46][47][48][49] Diverse alveolates, fungi, stramenopiles, choanoflagellates, amoebozoans and cercozoans, and many novel lineages of putative micro-eukaryotes were detected in molecular surveys of Lonar Lake sediments. Gene sequences of ciliated protozoans such asOxytricha longa and fungi belonging toCandida spp. were also recovered from lake sediment microcosms containing enriched populations of methylotrophic bacteria.[38] A new species of fungusCurvularia lonarensis has been described from the lake.[50]
Methylotrophs belonging toMethylomicrobium,Methylophaga andBacillus species have been identified in the Lonar Lake sediments.[51] Methane-oxidizing methylotrophs (methanotrophs) were also detected in the surface scum atop the lake water-column.[37] A novel species of non-methane-utilizing methylotrophMethylophaga lonarensis was isolated in pure culture from lake sediment microcosms.[52] This haloalkaliphilic bacterium synthesizes and intracellularly accumulates organic solutes such as ectoine that are of biotechnological interest.[52][53] Methylotrophic methanogenesis has been reported in Lonar Lake sediments and the primary microorganism (archaeon) that is responsible was identified as being closely related toMethanolobus oregonensis.[54]
Endolithic bacteria belonging to the phylaActinobacteria,Acidobacteria,Proteobacteria,Firmicutes,Cyanobacteria andBacteroidetes, and endolithic archaea belonging to the phylaThaumarchaeota andEuryarchaeota were detected in Lonar basalt rock samples that were retrieved from the crater walls and the lake-bed. The diversity and richness of endolithic bacteria in these samples were estimated to be higher than that of endolithic archaea. Most of the detected endolithic prokaryotes were identified as being putative methanotrophs, methanogens, phototrophs, ammonia-oxidizers, nitrogen-fixers, denitrifiers, dissimilatory sulfate-reducers and metal-reducers.[41]
Nonsymbioticnitrogen-fixing microorganisms such asHalomonas sp.,Paracoccus sp.,Klebsiella sp.,Slackia sp., andActinopolyspora sp. have been reported from this lake. All the nitrogen fixers arehaloalkaliphilic in nature as they can grow only at pH-11. Some of thebacteria andactinomycetes isolated from this lake are able to grow on some components of inorganic medium containingmartian soil simulant components.[55]
In early June 2020, the lake turned red/pink in a span of 2–3 days.[56][57][58] Reports byAgharkar Research Institute,National Environmental Engineering Research Institute andGeological Survey of India suggested that lowered water levels and high salinity caused growth ofHalobacterium and increasedCarotenoid levels, which in turn led to color change.[59][60][61]
Numerous temples surround the lake, most of which stand in ruins today, except for the temple of Daityasudana at the centre of the Lonar town, which was built in honour of Vishnu killing the asura Lonasura. It is a fine example of early Hindu architecture.[62]Vishnu,Shiva,Brahma,Lakshmi,Parvati,Sarasvati are deities present in other temples found inside the crater.
Daityasudana Temple is aVishnu temple created by theChalukya dynasty which ruled Central and Southern Indian subcontinent in the 6th century CE and 12th century CE. It belongs to theHemadpanthi class and is built in the form of an irregular star. It features carvings similar to those seen atKhajuraho temples. The deity of this temple is made of an ore with a high metal content that resembles stone. The ceiling of the temple has carvings. The exterior walls are also covered with carved figures. The plinth of the temple is about 1.5 m (4.9 ft) in height and the unfinished roof shows a pyramidal form for the tower.
The temple of Daityasudana at Lonar is the best example of theHemadpanthi style. From the standing image ofSurya in the principal niche on the back of the temple, it is conjectured that the temple was originally dedicated to Surya. However, in the present form it is aHindu temple to Vishnu as Daityasudana. Lonasura is anasura who lived in this place along with his siblings. He was killed by Vishnu as Daityasudana hence is the name.
The temple measures 32 m (105 ft). long by 25.8 m (84.5 ft). broad. It is a tree chamber temple, the inner most being sanctum sanctorum, where the statue of Vishnu standing atop dead Lonasura is there. The present day idol was made by Bholse rulers ofNagpur after the original was destroyed. The second chamber is antari where individual pooja are performed, on the roof of this block one created the statues ofVishnu killing Lonasura andKrishna killingKamsa,Narasimha killingHiranyakashipu andKrishna andRukmini. The outermost chamber is sabhamandapa which is meant for group offerings and performance. This portion as well as the entrance gate does not match the style and construction elements of the temple overall. The brickwork was added later to the unfinished temple, which was to various destructions in the 10th century CE.
The main entrance of the temple is east facing. The principle niche at the back of the temple has an image ofSurya, the sun god, which gives rise to the speculation that this might have been dedicated to him. The niche on south has an image ofChamunda. The one on left of the temple i.e. north hasNarasimha in it. All of these three niches are built like mini temples in themselves having elaborate pillars, base and decoration.
There are numerous ridges onto the temple with different decorations and significant images. Many of the images depict deities and incidents related to HinduPuranas.[63]
Lonar lake faces anthropological and environmental problems as listed below:
The crater is protected as a geological landmark and authorities have recognized the role of the historical and archaeological heritage in the lake. Nevertheless action is needed to prevent the adverse impact of settlements and religious festivities on the local ecosystem. Various civic activities (e.g. "Save Lonar") for the protection of Lonar crater are on-going.
Panoramic views of Lonar Crater
