Category: Geography Notes PPT

Derived from the source location Alabaston in Egypt, alabaster is a fine grained, variety of Gypsum (calcium sulfate). This massive form of Gypsum is a translucent, beautiful stone that has been prized for thousands of years. It is somewhat similar to marble, and owing to the two stones is often confused. Alabaster is quarried for centuries in Egypt and Italy, though most supposedly alabaster artifacts from ancient Egypt and Rome are actually marble stones.

Similar Stones Like Alabaster

Alabaster is often confused with different stones. So, here you will learn how to distinguish alabaster stone with other similar appearing stones. Supplementing the confusion, the word “onyx” has been applied differently to marble, alabaster, and true onyx, which is a type of quartz. The smooth, translucent appearance of alabaster reflects superbly polished marble or onyx. The variety of color and veining observed in different types of alabaster is also evocative of white or colored marble.

Marble, particularly white marble, is primarily a calcite (calcium carbonate). Both of them are metamorphic rocks, occurring geologically under high temperature and pressure. That being said, Alabaster is also often confused with steatite (soapstone), another soft, smooth, easily polished stone. Steatite consists of the mineral talc, which is even quite softer than alabaster. Most alabaster objects are found indoors, subjected to their susceptibility to moisture. These pieces are usually curatively carved, smoothly polished, and are often decorated or colored with gilding.

Chemical Formula of Alabaster

The chemical formula of Alabaster is :CaSO₄ · 2H₂O

Alabaster Scripture

Alabaster (gypsum— calcium sulfate), also a sedimentary rock, is a chemical accumulation. Different varieties of limestone and sandstone, which differ largely in quality and suitability for carving, are used for making the sculpture. Due to their process of occurrence, the “alabaster” of the ancients, is now defined as alabaster of gypsum, a calcium sulfate rock. These marbles are generally yellow or brown in color owing to the presence of iron oxide. Classic examples of alabaster scripture include the giallo antico (“antique yellow marble”) in Italian marble.

Alabaster Bible

In the primitive times of the biblical era, when a young woman reached the age of marriage, her family would buy an Alabaster Box for her and fill it with ointment which was called the alabaster ointment. The value of the ointment and the size of the box were to show the amount of wealth her family took possession of. When a man would ask her to marry him, she would reply by breaking this precious box at his feet; additionally to the expensive ointment on his feet was meant to submit him respect.

What Does Alabaster Mean in the Bible?

While Jesus was in Bethany, a woman came to him with an alabaster jar filled with very expensive perfume that she poured on his head as he was resting at the table. When the disciples discerned this visually, they were upset. “Why this misspend?” they asked. The alabaster co bible reflects around this nuance.

Significance of Alabaster Box and the Ointment Inside it

It is believed that the intriguing Alabaster box and the magical ointment inside it healed Jesus. The nuance behind the Alabaster box can possibly be seen in different lights and the fact that it is continually making mentions makes it curious as to why it was so significant and of such great importance to the people and the use on Jesus’s body.

The connotation is that the box was made of Alabaster stone, and since then it also became rather dangerous and difficult when you imagine a woman breaking the Alabaster box. The liquid inside the box has been described as an alabaster ointment containing a particular element called Myrrh that flows from a tree in Arabia and Africa.

Jesus was crucified; the ointment was used by those who would die by death of Martyrdom (the execution of Christ).

Mary— Lady in Waiting for marriage broke her Alabaster box to help Jesus, becoming God’s best while waiting for Mr. Right.” However, when Mary broke her Alabaster box to Jesus, it’s not that she was expecting to marry him, but it was a sign of honor.

Psalms Alabaster

Psalms alabaster is a reading absolutely stunning that will help to engage with God in a new way. It’s an insight into the intersection of beauty, humanity, and faith. Beauty matters in our comprehension of who God is. Everyone makes certain images and we are shaped by what we see and believe. Psalms alabaster is about bringing this visual reality to a faith-based aspect in context to divine authority and inspiration of the alabaster ministries Bible. The alabaster ministries and alabaster international ministry also conduct activities on educating, guiding on religious activities, conducting charity and personal development.

Have you noticed the change in colours of the leaves of the plants or trees etc. around you? It all happens because of the change of season. It is one of the four seasons on the Earth which comes after the summer season and comes before the winter season. Here, we will be talking about this season only. We will learn about the autumn fall, autumn season’s meaning or definition, autumn months, temperature and climate, how seasons change, autumn time, etc. This article will help you to understand the base of the geographical phenomenon and helps to understand one of the seasons on earth and its various features.

()

Autumn Meaning

Autumn is a “Latin” word that first appeared in the 14th century. It is also known as harvest or fall. It comes in between the seasons of summer and winter and it works as a transitional season between the two. It is the time when the temperature starts reducing and the weather starts bringing changes and becomes neither too hot nor too cold. In India, we have 6 seasons namely Summer, Monsoon, Autumn, Pre winter, Winter, and Spring. Autumn in Hindi is known as Sharad Ritu.

Definition

According to the Oxford dictionary, “ autumn is ​the season of the year between summer and winter when leaves change color and the weather becomes colder”

Change of Seasons

()

Our planet is tilted by 23.5° and if it is not tilted then half earth would face the day and half earth would face night but we know that it is not the case here. We experience seasons because of a number of factors such as the earth’s tilt, angle of incidence, division of the earth into equator, tropic of cancer, tropic of Capricorn, and the apparent movement of the sun. Our earth experiences four seasons i.e summer, autumn, winter, spring. Where the sun is directly overhead, that region of the Earth experiences maximum temperature which leads to summers and further the cycle continues. 

In Northern Hemisphere

Here, the Autumn season comes after the summer season, and regions experience autumn during September. At this time, the southern hemisphere experiences the spring season.

In Southern Hemisphere

Here, the Autumn season comes after the summer season but during the period of March. At this time, there is spring season in the northern hemisphere.

Difference Between Spring and Autumn

Autumn always comes after the summer season and spring comes after the winter season. In autumn, the temperature gradually decreases and in spring the temperature starts increasing. The Autumnal Equinox is related to the autumn season and the term vernal equinox is related to the spring season.

Autumn starts in the Northern hemisphere around the time of the month of September and lasts till all the cold winter months. It is mostly experienced by people around the globe towards the end of the year. Nights become longer than days and days last for a short time. Whereas, spring starts in the Northern hemisphere around the time of the month of March and lasts till all the summer months. It is mostly experienced by people around the globe at the beginning of the year. Days become longer than nights and nights last for a short time.

The Autumn season is well known as the cooling-off season as the temperatures everywhere start to go down and drop. And it is also known as the fall season. On the other hand, during the spring season temperatures start to rise in the daytime as it starts nearing the summer season.

The ecological variations brought about in the period of the autumn and spring seasons are also fairly opposing to one another. While the trees of most deciduous forests turn into lovely shades of orange, red, in addition yellow throughout the autumn season, spring brings forth a conflicting impact on flora. The spring season is marked by the growing of floras and of new leaves on trees.

All of these seasons are allied with very diverse connotations that are basically used in storybook works. Owing to its natural values, the season of autumn is related with wind-ups, whereas the spring season is related to the progress of new leaves and plants is a sign of new life.

The climatic alterations that go with each of these times of year are also unfriendly to one another. While autumn is typically known as the ‘cooling-off season’, the spring season starts with an equal increase in temperatures, in groundwork for the forthcoming summer months.

 

Temperature and Climate

The weather in the region starts changing gradually and the temperature starts decreasing. Generally, it is a season between the summers and the winters but in some areas, it also brings rainfall with itself. For example in India, the monsoon comes after the summer season and succeeds by the autumn and winter season. In some temperate regions, it is also the time of harvesting crops. People generally love autumn weather because it is neither too cold nor too hot. People enjoy this season and love to celebrate various festivals and traditions or occasions etc. but Autumn 2020 was the worst because of the Covid-19 pandemic and people did not get a chance to enjoy the beauty of this season.

Vegetation and Wildlife

()

It is one of the beautiful seasons of the year in which plants and trees start changing their colours. You will experience colours of autumn such as golden, yellow, orange and red, etc. It is the time when plants and trees start shedding their leaves as well. It is also a season of harvest on one side and a season of new crops on the other side. Apple, blackberry, brussels sprouts, cabbage, carrot, cauliflower, mustard, spinach, garlic, etc. are grown in this season.

This is a period of transition from one extreme season to another i.e from summers to winters. Animals start preparation for the winter season. Thicker fur grows on the bodies of the animals so that they are able to survive the winters. For example, rabbits, cats, dogs, birds, etc. Some animals go to hibernation where they keep their body temperature low and save their energy. For example, chipmunks or skunks, etc. Some animals start finding places like under the trees or rocks or caves etc. Birds start to migrate from one colder region to some warmer places. 

Autumn Traditions

It is quite a good time to celebrate any occasion or tradition or festival. A number of festivals or traditions are being celebrated during this period. For example, Dia de Muertos, Chuseok, Thanksgiving, Dussehra, and Diwali, etc.

 Reasons as to why Autumn is Considered the Best Season of All!

1. You can catch some birds in the course of migration

The fall is the time of the year when many species of birds make their way to the warmer climes towards the south in preparation for the upcoming chilly winter months. While each and every species has its own path, there are a few popular “flyways” where keen people from all over take the trip to have a look at the view.

2. You can be lucky enough to get a glimpse of the harvest moon

The full moon appears during the time of the autumn equinox when the Earth’s equator is utmost closely lining up with the centre of the sun, and the sun becomes brighter and rises before the full moon. This phenomenon happens around the months of September or October.

3. It is the best time to enjoy a campfire

While some people might also enjoy camping trips during the summer season, the fall, when leaves are altering their colour and the air is a bit cold, is debatably the best time to get out in nature. A campfire can be best enjoyed during this time with friends and family.

Conclusion 

Thus, here we have covered the autumn season and its various features. We come to know about the meaning of autumn, autumn months, and timing, etc. We learned actually how this change comes and how seasons change. This article will help you to understand the very basic concept of seasons and will help you in studying Geography or Earth Science.It is important to learn about seasons so that we can be aware of the passage of time and also for general knowledge. While some changes are obvious like hot and cold weather, changing seasons precisely is very fascinating and is also something everyone must be aware of.

Did You Know?

Dia de Muertos is a kind of a tradition when people paint their faces and take part in the parades etc. to remember their loved ones to whom they have lost in their lives and this tradition is being followed to remember and honor them.

The Cambrian Period is not to be the most ancient geological period of the Paleozoic Era and the Phanerozoic Eon. The Cambrian lived for 55.6 million years from the completion of the preceding Ediacaran Period 541 million years ago (mya) to the commencement of the Ordovician Period 485.4 mya. The period was authenticated as a “Cambrian series” by Adam Sedgwick, who identified it after Cambria, the Latin title for ‘Cymru’ (Wales), where Britain’s Cambrian rocks are completely revealed. 

Cambrian Distinguished from Extension

Thin mineralized animal fossils, including sponge spicules and likely worm tubes, are distinguished from the Ediacaran Period directly preceding the Cambrian. Some of the unique fossils of the biota from the Ediacaran may also have been animals delegate to living phyla, although this continues a somewhat debatable topic.

Cambrian Period Landscape

The topography of the Cambrian system differed greatly from such of the contemporary day. The geographic reorganisation is based on integrated geologic and biological proof. Fossils in continental-shelf sediments indicate the presence of at least three major faunal territories. This geographic analysis is supported by the presence of thick, warm-water carbonate-platform sediments that accumulated in a broad belt encircling the mainland.

Cambrian Location

The largest Cambrian faunal region is located around Gondwana, which stretched from the low northern latitudes to the high southern latitudes, just bare of the South Pole. The rocks and fossil associations of Gondwana show major changes that correspond to its great size and wide range of climates and environments. The Antarctic and Australian sectors of Gondwana halted in low latitudes through the Cambrian and have extensive carbonate deposits, although these of Antarctica are poorly exposed through the present-day polar ice cap. 

Scientific proof states that present-day North and South China were on separate tectonic plates. The fossil assemblies of South China have strong connections with those of both Australia and Kazakhstan, but details of the Cambrian geographic relationships reside unclearly.

At times, two almost reciprocally exclusive ecosystems are separated by temperature and salinity limits in the shallow water on the carbonate floors. Outer open-shelf films are characterized by high-diversity ecosystems that were widely disseminated around the continent. Fossils are usually the most copious and most diverse near the outer boundaries of the carbonate platform. Another Cambrian faunal territory surrounded the small continent of Baltica, which was discovered in middle to high southern latitudes. Cambrian shelf sediments of Baltica are relatively thin, rarely exceeding 250 metres (820 feet) in thickness, and are formed primarily of sandstone and shale. Seemingly as an outgrowth of cool-water environments, carbonate deposits are comparatively minor and very thin.

Cambrian Animals

Flora: The Cambrian vegetation was a little unusual from the Ediacaran. The principal taxa were the aquatic macroalgaeFuxianospira, Sinocylindra, and Marpolia. No calcareous macroalgae are distinguished from the period. Neither land plant (embryophyte) fossils are identified from the Cambrian. However, biofilms and microbial mats were well manifested on Cambrian tidal flats and beaches around 500 mya. Concerning this also microbes forming microbial Earth ecosystems, similar to modern soil crust of desert regions, adding to soil formation.

Fauna: As most animal growth during the Cambrian was aquatic. So all the causes of Fauna in the Cambrian period were Oceanic life. Trilobites were once considered to be the dominant life form at that time, but this has proven to be inaccurate. Arthropods were by far the most authoritative animals in the ocean, but trilobites were only an insignificant part of the total arthropod diversity. What made them so seemingly plentiful was their heavy armour augmented by calcium carbonate.

The period noted a step-change in the diversity and synthesis of Earth’s biosphere. The Ediacaran biota experienced a mass extinction at the start of the Cambrian Period, which resembled an increase in the excess and complexity of burrowing behaviour, which converted the seabed ecosystems. The seafloor was incorporated by microbial covers. By the completion of the Cambrian, burrowing animals had destroyed the mats in many domains through bioturbation. As a result, many of those organisms that were conditioned on the mats became obsolete. 

Around the same time, there was a rapid presence of delegates of all the mineralized phyla besides the Bryozoa, which emerged in the Lower Ordovician.

Approximately 515 million years ago, the number of species fitting extinct exceeded the number of new species which created mass extinction.

Clay minerals are the hydrous aluminium phyllosilicates that are available at times with varying amounts of iron, alkali, metals, magnesium, alkaline earth, and such other cations. They are generally found on or near some planetary surfaces. Clay minerals are formed mainly in the presence of water. They are proved to be very important to our life. Other theories of abiogenesis are involved in them. With them, they carry important constituents of the soils which have been beneficial to humans since time immemorial. 

 

In this Section, we will know about Various Types of Clay and Their Constituents. 

Kaolinite Clay or China Clay

The clay mineral is termed Kaolinite which has Al₂Si₂O5(OH)4 as its chemical composition. Kaolinite Clay is very much important as an industrial mineral. Kaolinite is a layered mineral of silicate coupled with silica which is SiO4, this is further linked through the oxygen atoms to an octahedral sheet of the alumina (AlO₆) octahedra. Rocks that are rich in kaolinite are called the kaolin or also known as China Clay. 

Bentonite

Bentonite is a type of absorbent swelling clay which majorly consists of montmorillonite.  This type of clay usually is formed from the weathering of the volcanic ash in the presence of seawater, after which it converts into volcanic gases that are present in the ash and clayey minerals. The Bentonite beds are white or pale blue or green in colour when exposed to fresh exposures, they can also turn to a cream colour and after which they can turn into yellow, red, or brown as the exposure is more.  

Montmorillonite

Montmorillonite is a very soft mineral that comes under the group of phyllosilicate minerals. These mineral forms when they precipitate from the water solution in the form of microscopic crystals. Called clay. This clay is named after Montmorillon in the country France.  The clay is in the ratio of 2:1, which means that it has two tetrahedral sheets of silica and a single octahedral sheet of the alumina. The particles are featured as plate-shaped with an average diameter of around 1 micrometer and have a thickness of about 0.96 nm. 

Powdered Bentonite

Bentonite clay is used by human beings to remove impurities on their skin, like oils, and other toxins from the body. This practice is done for thousands of years. Bentonite clay is also present in many skincare products. While some people also add this to foods or drinks with the aim to improve digestive issues or to remove toxins from the body.

Types of Clays

The main four types of clay are as follow:

• Earthenware clay

• Stoneware clay

• Ball clay

• Porcelain. 

All of these clays are used to make pottery. These seem all same but the texture, colour, and flexibilities differ a great deal.  

Tosudite

Magnesium Tosudite is a clay mineral with a 1:1 ratio interstratification of the compound name trioctahedral Mg chlorite and Sudoite and also dioctahedral Smectite.

Smectite

Smectite is also a clay mineral (like bentonite) that undergoes reversible expansion while absorbing the water.

Sepiolite

Sepiolite is the English name, while in German it is known as meerschaum which means ‘sea foam’. This is soft textured while clayey mineral which is often used in making tobacco pipes also called the meerschaum pipes. This is a complex magnesium silicate which is a specific chemical formula Mg4Si6O15(OH)2·6H2O, this can be present in the fibrous, fine-particulate, and solid forms.

Pyrophyllite

Pyrophyllite is a type of mineral which is phyllosilicate and this is composed of aluminium silicate hydroxide, the chemical formula which is Al2Si4O10(OH)2. This occurs in two forms crystalline folia and the form of compact masses, while there are distinct crystals as well which are well known.  

Pyrophyllite which occurs in the phyllite and schistose rocks is generally associated with kyanite used as an altered product.

Ball Clay

Ball clays are made up of kaolinitic sedimentary clays which are commonly constituted with 20–80% of kaolinite, 10 to 25% mica 6 to 5% of quartz. The localized seams in the same deposit have variations in their composition, this includes the quantity of these major minerals, which are accessorized minerals and carbonaceous materials like lignite. They form fine-grained and quite is quite plastic in nature, and this is unlike the earthenware clay. They produce fine quality pottery with white colour body.

Coral Bleaching Meaning – You might have heard about scuba diving. It’s a very beautiful and thrilling experience. Isn’t it? The beautiful and coloured corals can be seen under the sea. Do you know how these corals look so beautiful? They look so beautiful because their stunning colours come from marine algae called zooxanthellae. These algae live inside their tissue. The function of these tissues is to provide food to the corals. The corals can grow and reproduce with the help of these algae. 

When the corals are disturbed by external factors such as pollution or heat, they start expelling the algae. This leaves just the ghostly and transparent skeleton behind known as coral bleaching. When the algae leave the corals, it keeps fading until it looks like it is bleached. So, if we have to write the coral bleaching definition, we will write as – The leaving of algae from the corals, leaving the coral reef dead is called reef bleaching.

What Triggers Coral Reef Bleaching?

One of the most common coral bleaching causes is the change in the climate. We know that at present, global warming is the greatest threat to life on Earth. Because of global warming, planet Earth is warming up – the seas are warming up. This heating of ocean waters is one of the major causes of coral bleaching. There are other causes too such as pollution, overfishing, low tides, too much sunlight, and coastal development that causes coral to bleach. 

Effects of Coral Reef Bleaching

Coral reef bleaching is a threat to the environment. When these corals die, they never or rarely come back. The number of corals becomes limited and they struggle to reproduce. As a result, the coral family is extinguishing. 

Coral Bleaching’s Impact on Wildlife

Coral reefs are the support system for many biodiverse ecosystems. They are the source of survival for many species such as sea turtles, fishes, crabs, sea birds, jellyfishes, starfishes, shrimps, and many more. They provide shelter, spawning grounds, and protection to many species. Coral Reefs also are an important part of ocean food chains. As the coral reefs are destroyed because of bleachings, these marine lives and the ocean food chain gets disturbed and some species may face extinction. 

Coral Bleaching’s Impact on Humans

Coral reefs are a support system for humans living in coastal areas. They have an impact on people’s safety, food, and livelihoods. The Coral Reefs act as natural barriers to absorb the storm surges and the force of waves keeping the people of coastal areas safe. If there are no coral reefs, we have to build a seawall manually which will be very costly, will have fewer effects, and will be damaging to the environment. Coral bleaching also impacts fishes and the people who rely on fishes for their source of income. Also, coral reef tourism is a source of income for many individuals and also contributes to a nation’s economy. 

Do You Know?

The largest and richest coral reef in the world is the Great Barrier Reef. It has been protected since the 1970s. The fish population tripled after the marine sanctuary for Apo Island in the Philippines was created in the year 1982. The marine protected areas, where fishing and fishing methods are regulated, are called Reefs at Risk Revisited. The bleached great barrier reef is a threat to our marine beauty and also to humans.

How to Stop Coral Bleaching and Protect Coral Reefs?

Either we live in coastal areas or far from the sea, we can do our part to protect the coral reefs and stop coral bleaching. Whatever we do on the land, in some ways affects the water. So, we should take care of our activities to stop the pollution which will eventually impact global warming and other activities too so that the coral reef bleaching can be stopped. 

Here are a few to-do lists to stop coral bleaching and protect the coral reefs:

• While visiting the coral reefs, we should avoid touching them or disturbing them anyway. If we make any contact, it can damage the corals and may even kill them.

• The cosmetics that we use may harm the coral reefs. So, we should avoid cosmetics while visiting them.

• We should be careful while throwing the trash as marine trash is very harmful to the coral reefs. We should never throw plastics and other nonbiodegradable things near the beach or in the water to stop debris pollution. 

• The fertilizers that we use for the plants wash away in the water which harms the marine animals and the coral reefs. We should minimize the use of fertilizers. 

• We should try to reduce the emission of greenhouse gases. The emission of greenhouse gases causes ocean acidification and increases ocean temperature. This becomes one of the main causes of coral bleaching. 

Drumlin’s meaning is quite simple. Drumlins are elongated, oval-shaped or say teardrop-hills of rock, sand, and gravel. A drumlin is by and large made up of glacial drift, formed underneath an ice sheet or moving glacier and oriented in the direction of ice flow. There are no strict specifications with respect to the size of a drumlin but they tend to be up to a few kilometers up to 2 kilometers long and up to 50m in relief.

How Do Drumlins Form?

Drumlin glacier develops in the form of clusters apparently close to the terminus of glaciers. The mechanisms of formation are though disputed. They seemingly have significant interpretive value for rate and direction of glacial movement.

Drumlins are usually found in wide-ranging lowland regions, with their long axes approximately parallel to the path of glacial flow. Though they are observed in a multitude of shapes, the glacier side is always steep and high, while the lee side is tapered and smooth mildly in the direction of ice movement. Drumlins can hugely differ in size, with lengths from 1 to 2 km, heights from 50 to 100 feet, and widths from 400 to 600 m.

Regions of Formation of Drumlins

They are extensive in formerly glaciated regions and are particularly copious in Canada, Finland, Ireland, and Sweden.

Besides, Drumlins are mostly found in clusters with their numbering counting in the thousands. Often organized in belts, they impede drainage such that the small lakes and swamps may form between them. Large drumlin fields are situated in central New York and central Wisconsin; in northwestern Canada; and southwestern Nova Scotia.

Composition of Drumlins

Most drumlins are made up of till, but they may differ largely in their composition. Some contain substantial amounts of gravel, whereas others are composed of rock underlying the till surface (rock drumlins). Drumlins are most commonly linked with smaller, glacially streamlined bedrock forms referred to as roches moutonnées.

Eskers

Eskers are the geological structures that are formed when the glacial melted water carries the sediments and deposit through subglacial tunnels. Thus, they can give relevant information with regard to the shape and dynamics of glaciers and ice sheets whereas Drumlins are developed when the ice sheets move in streamline over the rock residue. These are elongated, oval shaped hills.

Drumlins and Eskers

Drumlins and Eskers by definition may seem similar, but there are still certain differences that you need to know about. These are as follows:-

Bedrock

Bedrock, the sediment of solid rock which is essentially buried beneath the soil and other splintered or segregated substances (regolith). Bedrock is composed of igneous, metamorphic or sedimentary rock, and it often caters to as the parent substance (the source of rock and mineral particles) for soil and regolith. In Earth’s nitrogen cycle, bedrock is also a source of nitrogen. A bedrock accumulation which takes place at Earth’s surface is known as an outcrop.