1.
Western Ghats
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Western Ghats மேற்கு தொடர்ச்சி மலை is a mountain range that runs parallel to the western coast of the Indian peninsula, located entirely in India. It is a UNESCO World Heritage Site and is one of the eight hottest hot-spots of biological diversity in the world and it is sometimes called the Great Escarpment of India. The range runs north to south along the edge of the Deccan Plateau. These hills cover 160,000 km2 and form the catchment area for complex riverine drainage systems that drain almost 40% of India, the Western Ghats block southwest monsoon winds from reaching the Deccan Plateau. The average elevation is around 1,200 m, at least 325 globally threatened species occur in the Western Ghats. The Western Ghats are the mountainous faulted and eroded edge of the Deccan Plateau, geologic evidence indicates that they were formed during the break-up of the supercontinent of Gondwana some 150 million years ago. Geophysical evidence indicates that the west coast of India came into being somewhere around 100 to 80 mya after it broke away from Madagascar, after the break-up, the western coast of India would have appeared as an abrupt cliff some 1,000 m in elevation. Basalt is the predominant rock found in the reaching a thickness of 3 km. Other rock types found are charnockites, granite gneiss, khondalites, leptynites, metamorphic gneisses with detached occurrences of limestone, iron ore. Residual laterite and bauxite ores are found in the southern hills. The Western Ghats extend from the Satpura Range in the north and it traverses south past the states of Maharashtra, Goa, Karnataka and Kerala. Major gaps in the range are the Goa Gap, between the Maharashtra and Karnataka sections, and the Palghat Gap on the Tamil Nadu and Kerala border between the Nilgiri Hills and the Anaimalai Hills. The mountains intercept the rain-bearing westerly monsoon winds, and are consequently an area of high rainfall, particularly on their western side. The northern portion of the coastal plain between the Western Ghats and the Arabian Sea is known as the Konkan, the central portion is called Kanara. The foothill region east of the Ghats in Maharashtra is known as Desh, the range is known as Sahyadri in Maharashtra and Karnataka. The Western Ghats meets the Eastern Ghats at Nilgiris in northwestern Tamil Nadu, Nilgiris connects Biligiriranga Hills in southeastern Karnataka with the Shevaroys and Tirumala hills. In the southern part of the range is Anamudi, the highest peak in Western Ghats, following is a list of some of the highest peaks of the Western Ghats, The Western Ghats form one of the four watersheds of India, feeding the perennial rivers of India. The major river systems originating in the Western Ghats include Godavari, Kaveri, Krishna, Thamiraparani, majority of streams draining the Western Ghats join these rivers and carry large volume of water during the monsoon months
2.
Matheran
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Matheran is a hill station and a municipal council in the Raigad district in the Indian state of Maharashtra. It is a station in Karjat Tahsil and is also the smallest hill station in India. It is located on the Western Ghats range at an elevation of around 800 m above sea level and it is located around 90 km from Mumbai, and 120 km from Pune. Matherans proximity to metropolitan cities makes it a popular weekend getaway for urban residents. Matheran, which means forest on the forehead is a region, declared by the Ministry of Environment, Forest and Climate Change. It is Asias only automobile-free hill station, There are around 38 designated look-out points in Matheran, including the Panorama Point that provides a 360 degree view of the surrounding area and also the Neral town. From this point, the view of sunset and sunrise is dramatic, the Louisa Point offers crystal clear view of the Prabal Fort. The other points are the One Tree Hill Point, Heart Point, Monkey Point, Porcupine Point, Rambagh Point, to stay there, there are plenty of hotels. There are a lot of Parsi bungalows. Beautiful old British-style architecture is preserved in Matheran, the roads are not metalled and are made of red laterite earth. There are many points in Matheran which give a view of the plains below. Matheran was identified by Hugh Poyntz Malet, the district collector of Thane district in May 1850. Lord Elphinstone, the then Governor of Bombay laid the foundations of the development as a hill station. The British developed Matheran as a resort to beat the summer heat in the region. Matheran is birthplace of freedom fighter Veer Bhai Kotwal. He was born on 1 December 1912 in a barber family, State Govt. has built a monument in his memory. The Matheran Hill Railway was built in 1907 by Sir Adamjee Peerbhoy and covers a distance of 20 km, over large swathes of forest territory. The Matheran hill railway, also known as Matheran Light Railway, was inspected by UNESCO world heritage site officials, indias other Hill Railways like the Darjeeling Railway, the Kangra Valley Railway, Nilgiri Mountain Railway are already on the list. Matheran has been declared an Eco-Sensitive zone by the Union Environment Ministry, a good collection of the dried plants is deposited in Blatter Herbarium, St. Xaviers College, Bombay, Mumbai
3.
India
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India, officially the Republic of India, is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and it is bounded by the Indian Ocean on the south, the Arabian Sea on the southwest, and the Bay of Bengal on the southeast. It shares land borders with Pakistan to the west, China, Nepal, and Bhutan to the northeast, in the Indian Ocean, India is in the vicinity of Sri Lanka and the Maldives. Indias Andaman and Nicobar Islands share a border with Thailand. The Indian subcontinent was home to the urban Indus Valley Civilisation of the 3rd millennium BCE, in the following millennium, the oldest scriptures associated with Hinduism began to be composed. Social stratification, based on caste, emerged in the first millennium BCE, early political consolidations took place under the Maurya and Gupta empires, the later peninsular Middle Kingdoms influenced cultures as far as southeast Asia. In the medieval era, Judaism, Zoroastrianism, Christianity, and Islam arrived, much of the north fell to the Delhi sultanate, the south was united under the Vijayanagara Empire. The economy expanded in the 17th century in the Mughal empire, in the mid-18th century, the subcontinent came under British East India Company rule, and in the mid-19th under British crown rule. A nationalist movement emerged in the late 19th century, which later, under Mahatma Gandhi, was noted for nonviolent resistance, in 2015, the Indian economy was the worlds seventh largest by nominal GDP and third largest by purchasing power parity. Following market-based economic reforms in 1991, India became one of the major economies and is considered a newly industrialised country. However, it continues to face the challenges of poverty, corruption, malnutrition, a nuclear weapons state and regional power, it has the third largest standing army in the world and ranks sixth in military expenditure among nations. India is a constitutional republic governed under a parliamentary system. It is a pluralistic, multilingual and multi-ethnic society and is home to a diversity of wildlife in a variety of protected habitats. The name India is derived from Indus, which originates from the Old Persian word Hindu, the latter term stems from the Sanskrit word Sindhu, which was the historical local appellation for the Indus River. The ancient Greeks referred to the Indians as Indoi, which translates as The people of the Indus, the geographical term Bharat, which is recognised by the Constitution of India as an official name for the country, is used by many Indian languages in its variations. Scholars believe it to be named after the Vedic tribe of Bharatas in the second millennium B. C. E and it is also traditionally associated with the rule of the legendary emperor Bharata. Gaṇarājya is the Sanskrit/Hindi term for republic dating back to the ancient times, hindustan is a Persian name for India dating back to the 3rd century B. C. E. It was introduced into India by the Mughals and widely used since then and its meaning varied, referring to a region that encompassed northern India and Pakistan or India in its entirety
4.
Volcano
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A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. Earths volcanoes occur because its crust is broken into 17 major, therefore, on Earth, volcanoes are generally found where tectonic plates are diverging or converging. This type of volcanism falls under the umbrella of plate hypothesis volcanism, Volcanism away from plate boundaries has also been explained as mantle plumes. These so-called hotspots, for example Hawaii, are postulated to arise from upwelling diapirs with magma from the boundary,3,000 km deep in the Earth. Volcanoes are usually not created where two plates slide past one another. Erupting volcanoes can pose hazards, not only in the immediate vicinity of the eruption. Historically, so-called volcanic winters have caused catastrophic famines, the word volcano is derived from the name of Vulcano, a volcanic island in the Aeolian Islands of Italy whose name in turn comes from Vulcan, the god of fire in Roman mythology. The study of volcanoes is called volcanology, sometimes spelled vulcanology, at the mid-oceanic ridges, two tectonic plates diverge from one another as new oceanic crust is formed by the cooling and solidifying of hot molten rock. Most divergent plate boundaries are at the bottom of the oceans, therefore, most volcanic activity is submarine, black smokers are evidence of this kind of volcanic activity. Where the mid-oceanic ridge is above sea-level, volcanic islands are formed, for example, subduction zones are places where two plates, usually an oceanic plate and a continental plate, collide. In this case, the plate subducts, or submerges under the continental plate forming a deep ocean trench just offshore. In a process called flux melting, water released from the subducting plate lowers the temperature of the overlying mantle wedge. This magma tends to be very viscous due to its high content, so it often does not reach the surface. When it does reach the surface, a volcano is formed, typical examples of this kind of volcano are Mount Etna and the volcanoes in the Pacific Ring of Fire. Because tectonic plates move across them, each volcano becomes dormant and is eventually re-formed as the plate advances over the postulated plume and this theory is currently under criticism, however. The most common perception of a volcano is of a mountain, spewing lava and poisonous gases from a crater at its summit, however. The features of volcanoes are more complicated and their structure. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater while others have features such as massive plateaus
5.
Flood basalt
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A flood basalt is the result of a giant volcanic eruption or series of eruptions that coats large stretches of land or the ocean floor with basalt lava. Flood basalt provinces such as the Deccan Traps of India are often called traps, rampino and Stothers cite eleven distinct flood basalt episodes occurring in the past 250 million years, creating large volcanic provinces, plateaus, and mountain ranges. However, more have been recognized such as the large Ontong Java Plateau, Large igneous provinces have been connected to five mass extinction events, and may be associated with bolide impacts. These have a low viscosity, which is why they flood rather than form taller volcanoes. Another explanation is that they result from the release, over a time period. The Deccan Traps of central India, the Siberian Traps, the Mesoproterozoic Mackenzie Large Igneous Province in Canada contains the Coppermine River flood basalts related to the Muskox layered intrusion. The maria on the Moon are additional, even more extensive, flood basalts on the ocean floor produce oceanic plateaus. The surface covered by one eruption can vary from around 200,000 km² to 1,500,000 km², the thickness can vary from 2000 metres to 12,000 m. These are smaller than the original due to erosion. Flood basalts have tholeiite and olivine compositions, the composition of the basalts from the Paraná is fairly typical of that of flood basalts, it contains phenocrysts occupying around 25% of the volume of rock in a fine-grained matrix. These phenocrysts are pyroxenes, plagioclases, opaque crystals such as titanium rich magnetite or ilmenite, sometimes more differentiated volcanic products such as andesites, dacites and rhyodacites have been observed, but only in small quantities at the top of former magma chambers. Subaerial flood basalts can be of two kinds, with a smooth or twisted surface, very compact surface, vesicles are rare, such lava flows may form underground rivers, when degassing fractures and conduits are present, very large flows may reach the surface. With a chaotic surface, the flood is very rich in bubbles of gas, with an irregular. In the Massif Central in Auvergne, France, there is an example of chaotic lava flow, produced by eruptions from Puy de la Vache. Geochemical analysis of the major oxides reveals a close to that of mid-ocean ridge basalts. These are in fact tholeiites with a silicon dioxide percentage close to 50% and it is this contamination that explains the difference between the two kinds of basalt mentioned above. The low phosphorus and titanium type has an excess of elements from the crust such as potassium and strontium, the content in incompatible elements of flood basalts is lower than that of ocean island basalts, but higher than that of mid-ocean ridge basalts. Basalt floods on the planet Venus are larger than those on Earth. S, magmatism at rift zones, The generation of volcanic continental margins and flood basalts
6.
Geology
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Geology is an earth science concerned with the solid Earth, the rocks of which it is composed, and the processes by which they change over time. Geology can also refer generally to the study of the features of any terrestrial planet. Geology gives insight into the history of the Earth by providing the evidence for plate tectonics, the evolutionary history of life. Geology also plays a role in engineering and is a major academic discipline. The majority of data comes from research on solid Earth materials. These typically fall into one of two categories, rock and unconsolidated material, the majority of research in geology is associated with the study of rock, as rock provides the primary record of the majority of the geologic history of the Earth. There are three types of rock, igneous, sedimentary, and metamorphic. The rock cycle is an important concept in geology which illustrates the relationships between three types of rock, and magma. When a rock crystallizes from melt, it is an igneous rock, the sedimentary rock can then be subsequently turned into a metamorphic rock due to heat and pressure and is then weathered, eroded, deposited, and lithified, ultimately becoming a sedimentary rock. Sedimentary rock may also be re-eroded and redeposited, and metamorphic rock may also undergo additional metamorphism, all three types of rocks may be re-melted, when this happens, a new magma is formed, from which an igneous rock may once again crystallize. Geologists also study unlithified material which typically comes from more recent deposits and these materials are superficial deposits which lie above the bedrock. Because of this, the study of material is often known as Quaternary geology. This includes the study of sediment and soils, including studies in geomorphology, sedimentology and this theory is supported by several types of observations, including seafloor spreading, and the global distribution of mountain terrain and seismicity. This coupling between rigid plates moving on the surface of the Earth and the mantle is called plate tectonics. The development of plate tectonics provided a basis for many observations of the solid Earth. Long linear regions of geologic features could be explained as plate boundaries, mid-ocean ridges, high regions on the seafloor where hydrothermal vents and volcanoes exist, were explained as divergent boundaries, where two plates move apart. Arcs of volcanoes and earthquakes were explained as convergent boundaries, where one plate subducts under another, transform boundaries, such as the San Andreas Fault system, resulted in widespread powerful earthquakes. Plate tectonics also provided a mechanism for Alfred Wegeners theory of continental drift and they also provided a driving force for crustal deformation, and a new setting for the observations of structural geology
7.
Ajanta Caves
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The Ajanta Caves in Aurangabad district of Maharashtra state of India are about 30 rock-cut Buddhist cave monuments which date from the 2nd century BCE to about 480 or 650 CE. According to UNESCO, these are masterpieces of Buddhist religious art that influenced Indian art that followed, the site is a protected monument in the care of the Archaeological Survey of India, and since 1983, the Ajanta Caves have been a UNESCO World Heritage Site. The Ajanta Caves constitute ancient monasteries and worship halls of different Buddhist traditions carved into a 250 feet wall of rock, textual records suggest that these caves served as a monsoon retreat for monks, as well as a resting site for merchants and pilgrims in ancient India. The Ajanta Caves site are mentioned in the memoirs of several medieval era Chinese Buddhist travelers to India and they were covered by jungle until accidentally discovered and brought to the Western attention in 1819 by a colonial British officer on a tiger hunting party. The Ajanta caves are located on the side of a cliff that is on the north side of a U-shaped gorge on the small river Waghur. Further round the gorge are a number of waterfalls, which when the river is high are audible from outside the caves, with the Ellora Caves, Ajanta is the major tourist attraction of the Marathwada region of Maharashtra. They are about 60 kilometres from Pachora Junction railway station,104 kilometres from the city of Aurangabad and they are 100 kilometres from the Ellora Caves, which contain Hindu, Jain as well as Buddhist caves, the last dating from a period similar to Ajanta. The Ajanta style is found in the Ellora Caves and other sites such as the Elephanta Caves. The Ajanta Caves are generally agreed to have made in two distinct periods, the first belonging to the 2nd century BCE to 1st century CE. The caves consist of 36 identifiable foundations, some of them discovered after the numbering of the caves from 1 through 29. The later identified caves have been suffixed with the letters of the alphabet, the cave numbering is a convention of convenience, and has nothing to do with chronological order of their construction. The earliest group constructed consists of caves 9,10,12,13 and this grouping and that they belong to the Hinayana tradition of Buddhism is generally accepted by scholars, but there are differing opinions on which century the early caves were built. According to Walter Spink, they were made during the period 100 BCE to 100 CE, other datings prefer the period of the Maurya Empire. Of these, caves 9 and 10 are stupa containing worship halls of chaitya-griha form, and caves 12,13, according to Spink, once the Satavahana period caves were made, the site was not further developed for a considerable period until the mid-5th century. However, the caves were in use during this dormant period. The second phase of construction at the Ajanta Caves site began in the 5th century, Spink, have argued that most of the work took place over the very brief period from 460 to 480 CE, during the reign of Hindu Emperor Harishena of the Vākāṭaka dynasty. This view has been criticised by scholars, but is now broadly accepted by most authors of general books on Indian art, for example Huntington. The second phase is attributed to the theistic Mahāyāna, or Greater Vehicle tradition of Buddhism, Caves of the second period are 1–8,11, 14–29, some possibly extensions of earlier caves
8.
Cretaceous
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The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic Period 145 million years ago to the beginning of the Paleogene Period 66 Mya. It is the last period of the Mesozoic Era, the Cretaceous Period is usually abbreviated K, for its German translation Kreide. The Cretaceous was a period with a warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites and rudists, during this time, new groups of mammals and birds, as well as flowering plants, appeared. The Cretaceous ended with a mass extinction, the Cretaceous–Paleogene extinction event, in which many groups, including non-avian dinosaurs, pterosaurs. The end of the Cretaceous is defined by the abrupt Cretaceous–Paleogene boundary, the name Cretaceous was derived from Latin creta, meaning chalk. The Cretaceous is divided into Early and Late Cretaceous epochs, or Lower and Upper Cretaceous series, in older literature the Cretaceous is sometimes divided into three series, Neocomian, Gallic and Senonian. A subdivision in eleven stages, all originating from European stratigraphy, is now used worldwide, in many parts of the world, alternative local subdivisions are still in use. As with other geologic periods, the rock beds of the Cretaceous are well identified. No great extinction or burst of diversity separates the Cretaceous from the Jurassic and this layer has been dated at 66.043 Ma. A140 Ma age for the Jurassic-Cretaceous boundary instead of the usually accepted 145 Ma was proposed in 2014 based on a study of Vaca Muerta Formation in Neuquén Basin. Víctor Ramos, one of the authors of the study proposing the 140 Ma boundary age sees the study as a first step toward formally changing the age in the International Union of Geological Sciences, due to the high sea level there was extensive space for such sedimentation. Because of the young age and great thickness of the system. Chalk is a type characteristic for the Cretaceous. It consists of coccoliths, microscopically small calcite skeletons of coccolithophores, the group is found in England, northern France, the low countries, northern Germany, Denmark and in the subsurface of the southern part of the North Sea. Chalk is not easily consolidated and the Chalk Group still consists of sediments in many places. The group also has other limestones and arenites, among the fossils it contains are sea urchins, belemnites, ammonites and sea reptiles such as Mosasaurus. In southern Europe, the Cretaceous is usually a marine system consisting of competent limestone beds or incompetent marls
9.
Lava
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Lava is the molten rock expelled by a volcano during an eruption. The resulting rock after solidification and cooling is called lava. The molten rock is formed in the interior of planets, including Earth. The source of the heat melts the rock within the earth is geothermal energy. When first erupted from a vent, lava is a liquid usually at temperatures from 700 to 1,200 °C. A lava flow is an outpouring of lava, which is created during a non-explosive effusive eruption. When it has stopped moving, lava solidifies to form igneous rock, the term lava flow is commonly shortened to lava. Although lava can be up to 100,000 times more viscous than water, lava can flow great distances before cooling and solidifying because of its thixotropic, explosive eruptions produce a mixture of volcanic ash and other fragments called tephra, rather than lava flows. The word lava comes from Italian, and is derived from the Latin word labes which means a fall or slide. The first use in connection with extruded magma was apparently in an account written by Francesco Serao on the eruption of Vesuvius between May 14 and June 4,1737. Serao described a flow of lava as an analogy to the flow of water. The composition of almost all lava of the Earths crust is dominated by silicate minerals, mostly feldspars, olivine, pyroxenes, amphiboles, micas, igneous rocks, which form lava flows when erupted, can be classified into three chemical types, felsic, intermediate, and mafic. These classes are primarily chemical, however, the chemistry of lava also tends to correlate with the temperature, its viscosity. Felsic or silicic lavas such as rhyolite and dacite typically form lava spines, most silicic lava flows are extremely viscous, and typically fragment as they extrude, producing blocky autobreccias. Felsic magmas can erupt at temperatures as low as 650 to 750 °C, unusually hot rhyolite lavas, however, may flow for distances of many tens of kilometres, such as in the Snake River Plain of the northwestern United States. Intermediate or andesitic lavas are lower in aluminium and silica, and usually somewhat richer in magnesium, intermediate lavas form andesite domes and block lavas, and may occur on steep composite volcanoes, such as in the Andes. Poorer in aluminium and silica than felsic lavas, and also commonly hotter, greater temperatures tend to destroy polymerized bonds within the magma, promoting more fluid behaviour and also a greater tendency to form phenocrysts. Higher iron and magnesium tends to manifest as a darker groundmass, mafic or basaltic lavas are typified by their high ferromagnesian content, and generally erupt at temperatures in excess of 950 °C
10.
Erosion
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In earth science, erosion is the action of surface processes that remove soil, rock, or dissolved material from one location on the Earths crust, then transport it away to another location. Eroded sediment or solutes may be transported just a few millimetres, the rates at which such processes act control how fast a surface is eroded. Feedbacks are also possible between rates of erosion and the amount of eroded material that is carried by, for example. Processes of erosion that produce sediment or solutes from a place contrast with those of deposition, while erosion is a natural process, human activities have increased by 10-40 times the rate at which erosion is occurring globally. At well-known agriculture sites such as the Appalachian Mountains, intensive farming practices have caused erosion up to 100x the speed of the rate of erosion in the region. Excessive erosion causes both on-site and off-site problems, on-site impacts include decreases in agricultural productivity and ecological collapse, both because of loss of the nutrient-rich upper soil layers. In some cases, the end result is desertification. Off-site effects include sedimentation of waterways and eutrophication of bodies, as well as sediment-related damage to roads. Intensive agriculture, deforestation, roads, anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion, however, there are many prevention and remediation practices that can curtail or limit erosion of vulnerable soils. Rainfall, and the surface runoff which may result from rainfall, produces four types of soil erosion, splash erosion, sheet erosion, rill erosion. Splash erosion is generally seen as the first and least severe stage in the erosion process. In splash erosion, the impact of a falling raindrop creates a crater in the soil. The distance these soil particles travel can be as much as 0.6 m vertically and 1.5 m horizontally on level ground. If the soil is saturated, or if the rate is greater than the rate at which water can infiltrate into the soil. If the runoff has sufficient flow energy, it will transport loosened soil particles down the slope, sheet erosion is the transport of loosened soil particles by overland flow. Rill erosion refers to the development of small, ephemeral concentrated flow paths which function as both sediment source and sediment delivery systems for erosion on hillslopes, generally, where water erosion rates on disturbed upland areas are greatest, rills are active. Flow depths in rills are typically of the order of a few centimetres or less and this means that rills exhibit hydraulic physics very different from water flowing through the deeper, wider channels of streams and rivers. Gully erosion occurs when water accumulates and rapidly flows in narrow channels during or immediately after heavy rains or melting snow
11.
Climate change
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Climate change is a change in the statistical distribution of weather patterns when that change lasts for an extended period of time. Climate change may refer to a change in weather conditions. Climate change is caused by such as biotic processes, variations in solar radiation received by Earth, plate tectonics. Certain human activities have also identified as significant causes of recent climate change. Scientists actively work to understand past and future climate by using observations, more recent data are provided by the instrumental record. The most general definition of change is a change in the statistical properties of the climate system when considered over long periods of time. Accordingly, fluctuations over periods shorter than a few decades, such as El Niño, the term climate change is often used to refer specifically to anthropogenic climate change. Anthropogenic climate change is caused by activity, as opposed to changes in climate that may have resulted as part of Earths natural processes. In this sense, especially in the context of environmental policy, within scientific journals, global warming refers to surface temperature increases while climate change includes global warming and everything else that increasing greenhouse gas levels affect. A related term is climatic change, in 1966, the World Meteorological Organization proposed the term climatic change to encompass all forms of climatic variability on time-scales longer than 10 years, regardless of cause. Change was a given and climatic was used as an adjective to describe this kind of change, when it was realized that human activities had a potential to drastically alter the climate, the term climate change replaced climatic change as the dominant term to reflect an anthropogenic cause. Climate change was incorporated in the title of the Intergovernmental Panel on Climate Change, Climate change, used as a noun, became an issue rather than the technical description of changing weather. On the broadest scale, the rate at which energy is received from the Sun and this energy is distributed around the globe by winds, ocean currents, and other mechanisms to affect the climates of different regions. Factors that can shape climate are called climate forcings or forcing mechanisms, there are a variety of climate change feedbacks that can either amplify or diminish the initial forcing. Some parts of the system, such as the oceans and ice caps, respond more slowly in reaction to climate forcings. There are also key factors which when exceeded can produce rapid change. Forcing mechanisms can be internal or external. Internal forcing mechanisms are natural processes within the system itself
12.
Zeolite
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Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents and catalysts. Based on this, he called the material zeolite, from the Greek ζέω, meaning to boil and λίθος, the classic reference for the field has been Zeolite molecular sieves, structure, chemistry, and use by Donald W. Breck. Zeolites occur naturally but are produced industrially on a large scale. As of September 2016,232 unique zeolite frameworks have been identified, every new zeolite structure that is obtained has to be approved by the International Zeolite Association Structure Commission and receives a three letter designation. Zeolites have a structure that can accommodate a wide variety of cations, such as Na+, K+, Ca2+, Mg2+. These positive ions are rather loosely held and can readily be exchanged for others in a contact solution, some of the more common mineral zeolites are analcime, chabazite, clinoptilolite, heulandite, natrolite, phillipsite, and stilbite. An example of the formula of a zeolite is, Na2Al2Si3O10·2H2O. Natural zeolites form where volcanic rocks and ash layers react with alkaline groundwater, Zeolites also crystallize in post-depositional environments over periods ranging from thousands to millions of years in shallow marine basins. Naturally occurring zeolites are rarely pure and are contaminated to varying degrees by other minerals, metals, quartz, for this reason, naturally occurring zeolites are excluded from many important commercial applications where uniformity and purity are essential. Zeolites are the members of the family of microporous solids known as molecular sieves mainly consisting of Si, Al, O, and metals including Ti, Sn, Zn. The term molecular sieve refers to a property of these materials. This is due to a very regular structure of molecular dimensions. The maximum size of the molecular or ionic species that can enter the pores of a zeolite is controlled by the dimensions of the channels, therefore, the pores in many zeolites are not cylindrical. Zeolites transform to other minerals under weathering, hydrothermal alteration or metamorphic conditions, the sequence of silica-poor volcanic rocks commonly progresses from, Cowlesite → levyne–offretite → analcime → thomsonite–mesolite-scolecite → chabazite → calcite. Industrially important zeolites are produced synthetically, typical procedures entail heating aqueous solutions of alumina and silica with sodium hydroxide. Equivalent reagents include sodium aluminate and sodium silicate, further variations include changes in the cations to include quaternary ammonium cations. Synthetic zeolites hold some key advantages over their natural analogues, the synthetic materials are manufactured in a uniform, phase-pure state. It is also possible to produce zeolite structures that do not appear in nature, Zeolite A is a well-known example
