Category Ecology

WHAT TREE HAS 2 TYPES OF LEAVES?

Redwood trees have been studied extensively but only recently did the scientist discover that they have two types of leaves – peripheral leaves and axial leaves – that look different and perform different tasks. They help redwood trees adapt to both wet and dry conditions – an ability that could be key to their survival in a changing climate. Redwoods are among those super-trees that can survive pest attacks, fire and even perhaps climate change. They are also among the planet’s biggest, tallest and oldest trees.

Unlike each other

While the peripheral leaf takes care of the food preparation via photosynthesis, the axial is devoted to absorbing water. A large redwood can absorb up to 14 gallons of water in just the first hour its leaves are wet!

The two types of leaves look different from each other, inside out. When scientists looked at the leaves under a microscope, they understood that they were completely different from each other. The axial leaves were packed with water storage cells, but their phloem- tubes in the leaves that export photosynthetic sugars to the tree – appeared to be blocked and useless.

Adaptation technique

Analysis showed that the redwoods’ axial leaves account for only about 5% of the trees’ total leaf area, and barely produce enough energy through photosynthesis to maintain themselves. But they contribute up to 30% of the trees’ total water absorption capacity.

Together these two types of leaves balance the dual requirements of photosynthesis and water absorption, allowing redwoods to thrive in both wet and dry habitats.

Redwoods are found in both wet and dry environments with intense seasonal variation. In the wet, rainy areas, the axial is found on the tree’s lower branches, leaving the upper, sunnier levels to the peripheral leaf type. This completely flips for redwoods in drier areas: The axial leaves live among the tree’s higher levels to take more advantage of fog and rain, which occur less often in the drier environment.

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WHAT IS A WADI?

A wadi is a freshwater ecosystem and a type of fluvial landform, which is considered any type of geological feature that is related to rivers or streams. The term wadi comes from both the Arabic and Hebrew languages. Specifically, it refers to a dry riverbed that contains water during rainy seasons and is located in a valley-like area of the desert.

Characteristics Of a Wadi

Wadis are generally located in the flat or slightly rolling areas of deserts and often leads to dry lakes as well. A wadi can be recognized by its braided appearance, which is caused by a lack of constant water flow and an excess of sediment build-up. Sometimes, this sediment may collect in significant amounts, blocking water flow and effectively changing the direction of seasonal rivers. In addition to the low water levels, wind also affects sediment buildup by bringing in dry sands that collect on top of moist sand.

The bottoms of wadis are often covered in sand and loose gravel. The lower levels of this sediment are often packed very densely. This means that during rainy season, water is not quickly absorbed by the ground and has nowhere to drain, resulting in rapid flooding. Flash flooding in wadis is made even more dangerous because of the previously mentioned directional changes, which can send waters into communities unexpectedly.

Credit: World Atlas

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WHAT IS AN OASIS?

An oasis is where water from a source deep underground comes to the surface in a desert, supporting life and vegetation.

An oasis is a lush green area in the middle of a desert, centered around a natural spring or a well. It is almost a reverse island, in a sense, because it is a tiny area of water surrounded by a sea of sand or rock.

Oases can be fairly easy to spot—at least in deserts that do not have towering sand dunes. In many cases, the oasis will be the only place where trees such as date palms grow for miles around. For centuries, the sight of an oasis on the horizon has been a very welcome one for desert travelers.

Scientific Explanation

It seems amazing that trees could sprout in an oasis. Where do the seeds come from? As it happens, scientists believe that migrating birds spot the glint of water from the air and swoop down for a drink. Any seeds that they happen to have swallowed earlier will be deposited in the damp sand around the waterhole, and those seeds that are hard enough will sprout, providing the oasis with its tell-tale splash of color in the sand.

Caravans in desert areas such as Africa’s Sahara or the dry regions of Central Asia have long depended on such oases for food and water, both for their camels and their drivers, during difficult desert crossings. Today, some pastoral peoples in western Africa still depend on oases to keep themselves and their livestock alive as they travel through deserts between different grazing areas. In addition, many kinds of desert-adapted wildlife will seek water and also take shelter from the blazing sun in local oases.

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WHAT ARE FJORDS?

Fjords are very deep, long and narrow inlets with steep sides or sheer cliffs, seen along the coasts of Norway, New Zealand and Canada. A fjord is formed when the sea comes in to fill the U-shaped valley left by a glacier after it has retreated.

A fjord is a long, deep, narrow body of water that reaches far inland. Fjords are often set in a U-shaped valley with steep walls of rock on either side.

Fjords are found mainly in Norway, Chile, New Zealand, Canada, Greenland, and the U.S. state of Alaska. Sognefjorden, a fjord in Norway, is more than 160 kilometers (nearly 100 miles) long.

Fjords were created by glaciers. In the Earth’s last ice age, glaciers covered just about everything. Glaciers move very slowly over time, and can greatly alter the landscape once they have moved through an area. This process is called glaciation.

Glaciation carves deep valleys. This is why fjords can be thousands of meters deep. Fjords are usually deepest farther inland, where the glacial force was strongest.

Some features of fjords include coral reefs and rocky islands called skerries.

Some of the largest coral reefs are found at the bottom of fjords in Norway. They are home to several types of fish, plankton and sea anemones. Some coral reefs are also found in New Zealand. Scientists know much less about these deep, cold-water reefs than they do about tropical coral reefs. But they have learned that the living things in cold-water reefs prefer total darkness. Organisms in cold-water reefs have also adapted to life under high pressure. At the bottom of a fjord, the water pressure can be hundreds or even thousands of kilograms per square meter. Few organisms can survive in this cold, dark habitat.

Skerries are also found around fjords. A skerry is a small, rocky island created through glaciation. Most of the Scandinavian coastline is cut into thousands of little blocks of land. These jagged bits of coastline are skerries. The U.S. states of Washington and Alaska also have skerries.

Even though skerries can be hard to get around in a boat, fjords are generally calm and protected. This makes them popular harbors for ships.

Credit:  National Geographic Society

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How are mountains created?

Most of the world’s greatest mountain ranges the Himalayas, the Andes, the Rockies, the Caucasus and the Alps were created as Earth’s tectonic plates collided. As the huge tectonic masses crashed into each other, they forced the layers of rock to fold. This is why these mountains form long, narrow ranges along the edges of continents. Mountains are also created as powerful earthquakes move Earth’s crust and lift up huge blocks of rock. Volcanic eruptions can also create mountains.

Mountains are formed by movement within the Earth’s crust. The crust itself is made up of several large plates, called tectonic plates, which are free floating. These huge chunks of the Earth’s crust move within molten rock called magma, which allows them to shift and collide over time. Even though humans live on the crust, they do not often feel these movements as they are very slow, and the sheer size of each plate is so large. Nevertheless, these shifts still have great impacts on human life as the movement of plates is what creates changes in the geographical structure of the surface of the earth. In this way, mountains are created over time. When these plates collide, there is a great deal of mass and pressure which suddenly comes to a stop, and it is this movement that forces the Earth into buckles or protrusions which are known as mountains. Depending on how these plates move or collide, one of three types of mountains can be formed. The three types of mountains or mountain ranges are: volcanic, fold, and Block Mountains, each of which is formed in a different way.

Volcanic Mountains:

Volcanic mountains are formed when a tectonic plate is pushed beneath another (or above a mid-ocean ridge or hotspot) where magma is forced to the surface. When the magma reaches the surface, it often builds a volcanic mountain, such as s shield volcano or a strato-volcano.

Fold Mountains:

As the name suggests, Fold Mountains occur when two tectonic plates collide at a convergent plate boundary, causing the crust to over thicken. This process forces the less dense crust to float on top of the denser mantle rocks – with material being forced upwards to form hills, plateaus or mountains – while a greater volume of material is forced downward into the mantle.

Block Mountains:

Block Mountains are caused by faults in the crust, a seam where rocks can move past each other. Also known as rifting, this process occurs when rocks on one side of a fault rise relative to the other. The uplifted blocks become Block Mountains (also known as horsts) while the intervening dropped blocks are known as graben (i.e. depressed regions).

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NAME EUROPE’S HIGHEST MOUNTAIN?

Mont Blanc, Italian Monte Bianco, mountain massif and highest peak (15,771 feet [4,807 metres]) in Europe. Located in the Alps, the massif lies along the French-Italian border and reaches into Switzerland. It extends southwestward from Martigny, Switzerland, for about 25 miles (40 km) and has a maximum width of 10 miles (16 km). The summit is in French territory. Surrounding the massif are the Graian Alps (south), the Chamonix Valley and Savoy Alps (west), the Pennine Alps (northeast), and the Valley of Courmayeur (east). Other principal peaks within the massif include Mont Blanc du Tacul, Mont Maudit, Aiguille (“Peak”) du Géant, Les Grandes Jorasses, Mont Dolent, and Aiguille du Midi.

Glaciers cover approximately 40 square miles (100 square km) of Mont Blanc (whence its name, meaning “white mountain”). Ice streams stretch from the central ice dome down to below 4,900 feet (1,490 metres). The Mer de Glace, the second longest glacier in the Alps, reached the elevation of 4,100 feet (1,250 metres) in 1930. At the beginning of the 17th century, glaciers advanced to the bottom of the Chamonix Valley, destroying or burying cultivated land and dwellings. Since that time, the glaciers have periodically advanced and retreated.

 

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WHICH Is JAPAN’S HIGHEST MOUNTAIN?

Japan’s highest mountain, peaking at 3776 m, is Mount Fuji, an active volcano that sits on a triple junction of tectonic activity. Interestingly, it is made up of three different volcanoes. At the base is Komitake, in the middle, Kofuji, and at the top is Mount Fuji. The volcano last erupted in December, 1707.

Mount Fuji is a symbol of Japan. The mountain contributes to Japan’s physical, cultural, and spiritual geography.

Mount Fuji is the tallest mountain in Japan, standing at 3,776 meters (12,380 feet). It is an active volcano, sitting on a “triple junction” of tectonic activity: the Amurian plate (associated with the Eurasian tectonic plate), the Okhotsk plate (associated with the North American plate) and the Filipino plate all converge in the region beneath Mount Fuji. It is only 100 kilometers (62 miles) from Tokyo, Japan’s capital and largest city. In fact, the last time Mount Fuji erupted, in 1707, volcanic ash fell on Tokyo.

Mount Fuji is the single most popular tourist site in Japan, for both Japanese and foreign tourists. More than 200,000 people climb to the summit every year, mostly during the warmer summer months. “Huts” on the route up the mountains cater to climbers, providing refreshments, basic medical supplies, and room to rest. Many people start climbing Mount Fuji at night, as better to experience sunrise from the summit—Japan, after all, is nicknamed “the Land of the Rising Sun.” The sunrise from Mount Fuji has a special name, Goraiko.

Mount Fuji has been a sacred site for practicers of Shinto since at least the 7th century. Shinto is the indigenous faith or spirituality of Japan, many Shinto shrines dot the base and ascent of Mount Fuji. Shinto shrines honor kami, the supernatural deities of the Shinto faith. The kami of Mount Fuji is Princess Konohanasakuya, whose symbol is the cherry blossom. Konohanasakuya has an entire series of shrines, called Segen shrines. The main Segen shrines are at the base and summit of Mount Fuji, but there are more than 1,000 across all of Japan.

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WHY ARE SOME MOUNTAINS SNOW-CAPPED?

As altitude increases, the air gets colder. There comes a certain height, called the snow line, above which it is always too cold for the snow to melt, which is why some mountaintops are snow-capped all year round. The snowline is at 5000m in the tropics, 2700 m in the Alps and at sea level at the poles.

The top of the mountain is actually its coldest spot. As you climb a mountain to a higher altitude (height), the atmosphere gets thinner and thinner. This is because air pressure decreases with altitude.

Even though warm air rises, as it does so the rising air expands and cools. When it expands and cools, it can’t absorb and retain heat the way it does at the bottom of the mountain.

Although mountaintops are closer to the Sun, they’re also farther away from the thermal heat of the Earth’s core that keeps the ground warm. So the top of the mountain can be much colder than the bottom.

In fact, the bottom of a mountain can be located in a tropical jungle while the top of the mountain has snow on it! That’s why it’s possible to have snow at the equator.

Cooler temperatures at the top of a mountain also mean that there’s less evaporation taking place. This leads to greater amounts of moisture in the air. More moisture means more rain and, at the very top of a mountain, more snow.

Not all mountains have snowcaps, and not all mountains that get snow have snowcaps all year. A lot depends upon their location and how tall they are. Mountains lower in altitude are less likely to have snowcaps or to have them all year long.

Many mountains, though, have snowcaps year-round. Above a certain point — called the snow line — it stays cold enough that the snow never melts.

The height of the snow line varies around the globe. It depends upon both altitude (height of the mountain) and latitude (where the mountain is located). The snow line is much higher near the equator (about 15,000 feet), for example, than it is near the poles (sea level or 0 feet in altitude).

The snow line can be affected by other factors, too. For example, in the Andes Mountains of South America, it is so dry that the mountains rarely see snow, despite their height and distance from the equator. Monte Pissis in Argentina is the tallest mountain in the world without a permanent snowcap.

Mountains that are near coastlines may have a lower snow line than other areas with the same altitude and latitude. As you get closer to a coastline, the amount of moisture in the air tends to produce more snowfall at higher altitudes.

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Why have beach sands different colors?

Sand is basically the small particles of eroded larger rocks. The erosion is caused by several factors, including water and wind. Depending on the geography, the composition and colours of the sand vary. For instance, beach sand could be lighter because of calcium carbonate desposits from shells and skeletons of marine creatures. Meanwhile, desert sand comprises fine, light-weight particles that have been brought in by wind. River sand is likely to be coarse, containing even bright-coloured stones.

On some beaches, sand grain size composition varies with distance from the water. A greater proportion of finer, smaller sand grains may be pushed higher up the beach by waves or by wind, whereas larger, coarser grains are deposited closer to the water. However, beaches are complex and highly variable environments, and there are many areas where this distribution is not found because there are many conditions that affect sand size and distribution. Additional factors influencing sand grain size include the nearshore and offshore seafloor features, substrate type, sand source, currents, wind exposure, and coastline shape.

Beach sand can appear fairly uniform, but it is actually a complex mixture of substances with various dimensions. When scientists study sand, some qualities are particularly useful in characterizing the type of sand. These qualities include the colors, texture, and size of the sand grains and their material origins. In general, sand observations can be divided into three broad categories:

observations about size,

observations about shape, and

observations about the probable source of the sand.

 From these three characteristics scientists can learn about the physical, chemical, and biological processes at the beach from which the sand came.

The Wentworth scale is one system used to classify sediments, including sand, by grain size. The word sediment is a general term for mineral particles, for example individual sand grains, which have been created by the weathering of rocks and soil and transported by natural processes, like water and wind. In decreasing order of size, sediments include boulders, gravel, sand, and silt.

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WHO STUDIES ROCKS AND MINERALS?

A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, although backgrounds in physics, chemistry, biology, and other sciences are also useful. Field research (field work) is an important component of geology, although many subdisciplines incorporate laboratory and digitalised work.

Geologists work in the energy and mining sectors searching for natural resources such as petroleum, natural gas, precious and base metals. They are also in the forefront of preventing and mitigating damage from natural hazards and disasters such as earthquakes, volcanoes, tsunamis and landslides. Their studies are used to warn the general public of the occurrence of these events. Geologists are also important contributors to climate change discussions.

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WHAT IS FLUORITE?

Fluorite is a very popular mineral, and it naturally occurs in all colors of the spectrum. It is one of the most varied colored minerals in the mineral kingdom, and the colors may be very intense and almost electric. Pure Fluorite is colorless; the color variations are caused by various impurities. Some colors are deeply colored, and are especially pretty in large well-formed crystals, which Fluorite often forms. Sometimes coloring is caused by hydrocarbons, which can be removed from a specimen by heating. Some dealers may apply oil treatment upon amateur Fluorite specimens to enhance luster.

Fluorite has interesting cleavage habits. The perfect cleavage parallel to the octahedral faces can sometimes be peeled off to smooth out a crystal into a perfect octahedron. Many crystals, especially larger ones, have their edges or sections chipped off because of the cleavage.

Fluorite is one of the more famous fluorescent minerals. Many specimens strongly fluoresce, in a great variation of color. In fact, the word “fluorescent” is derived from the mineral Fluorite. The name of the element fluorine is also derived from Fluorite, as Fluorite is by far the most common and well-known fluorine mineral.

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WHY ARE AMETHYSTS PURPLE?

The color in amethyst comes from color centers in the quartz. These are created when trace amounts of iron are irradiated ( from the natural radiation in the rocks).

The purple color in ghost town glass comes from small amounts of manganese in the glass when it has been exposed to ultraviolet light. The manganese was used as a clarifying ingredient in glass from 1860 to 1915. Prior to that, lead was used, and subsequently, selenium is used.

Quartz will commonly contain trace amounts of iron ( in the range of 10’s to 100’s parts per million of iron). Some of this iron sits in sites normally occupied by silicon and some is interstitial (in sites where there is normally not an atom). The iron is usually in the +3 valence state.

Gamma ray radiation can knock an electron from an iron lattice site and deposit the electron in an interstitial iron. This +4 iron absorbs certain wavelengths (357 and 545 nanometers) of light causing the amethyst color. You need to have quartz that contains the right amounts of iron and then is subjected to enough natural radiation to cause the color centers to form.

The color of amethyst has been demonstrated to result from substitution by irradiation of trivalent iron (Fe+3) for silicon in the structure, in the presence of trace elements of large ionic radius, and, to a certain extent, the amethyst color can naturally result from displacement of transition elements even if the iron concentration is low.

Amethyst occurs in primary hues from a light pinkish violet to a deep purple. Amethyst may exhibit one or both secondary hues, red and blue. The best varieties of amethyst can be found in Siberia, Sri Lanka, Brazil and the far East. The ideal grade is called “Deep Siberian” and has a primary purple hue of around 75–80%, with 15–20% blue and (depending on the light source) red secondary hues.

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WHAT ARE VALUABLE MINERALS?

Valuable minerals are either metal or rock that can be processed and converted for economic purposes. Gemstones such as diamonds, rubies, sapphires and emeralds are valuable minerals. Gold and silver are also precious. Palladium is considered more precious than gold and it is very valuable to automotive industries.

Diamond

Diamond is commercially the most popular mineral because of its eminent role in the world of jewelry trading.

 Rubies

Rubies are considered to be the most expensive gemstones in the world. They get their alluring red color from the presence of chromium. The largest supply of this mineral was harvested in Burma, which is known as the Mecca for rubies.

Gold

Many people think gold is the most valuable and most expensive mineral in the world, but this is a common misconception because there are other minerals that are far more worthy than gold. Still, it is a highly valued, expensive mineral.

Rhodium

Because of its rarity and industrial application, this silver-white noble metal is the world’s most expensive mineral. Rhodium became popular as a result of its highly valued catalytic application in the automotive industry. The largest supply of this mineral was found in 2009 in South Africa and Russia.

Lithium

This mineral which is commonly known as a crucial ingredient in the production of rechargeable batteries was first discovered in 1817 in Stockholm by the Swedish chemist Johan August Arfvedson. Lithium is a highly valued mineral which represents a billion dollar industry. The largest supplies of this mineral are found in Afghanistan.

Blue Garnet

Garnets can be found in various colors like brown, green, orange, pink, purple, red and yellow. Among all these colors the blue garnet is the only one with a considerably high value. This mineral was first discovered in the 1990s in Madagascar, and since then it has been mined in Russia, Turkey and the United States.

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WHY ARE DIAMONDS EXTRAORDINARY?

Very hard, very rare and very old, diamonds are essentially carbon that has been transformed under great pressure deep inside Earth. It is usually volcanic activity that brings them near the surface again after billions of years and makes mining possible. Diamonds are the hardest natural substance ever found.

  1. The ancient Romans and Greeks believed that diamonds were tears cried by the gods or splinters from falling stars, and Romans believed that Cupid’s arrows were tipped with diamonds (perhaps the earliest association between diamonds and romantic love).
  2. Diamonds are nearly as old as the earth and take billions of years to form deep in the pit of the earth. Very few diamonds survive the trip from the depths of the earth to the crust where they can be mined. No two diamonds are the same and carry their own unique properties such as internal inclusions and color. 
  3. Diamonds form about 100 miles below ground and have been carried to the earth’s surface by deep volcanic eruptions.
  4. Diamonds are made of a single element—they are nearly 100% carbon. Under the extreme heat and pressure far below the earth’s surface, the carbon atoms bond in a unique way that results in diamonds’ beautiful and rare crystalline structure.
  5. The word diamond derives from the Greek word “adamas,” which means invincible or indestructible.
  6. Diamonds are the hardest natural substance on earth ranking a 10 on the Mohs Scale of Hardness. The only thing that can scratch a diamond’s surface is another diamond.
  7. Diamonds have been valued and coveted for thousands of years by the likes of royalty and mythical beings. There is evidence that diamonds were being collected and traded in India as early as the fourth century BC. In the first century AD, the Roman naturalist Pliny is quoted as having said, “Diamond is the most valuable, not only of precious stones, but of all things in this world.”
  8. Ancient Hindus used diamonds in the eyes of devotional statues and believed that a diamond could protect its wearer from danger.
  9. Many ancient cultures believed that diamonds gave the wearer strength and courage during battle, and some kings wore diamonds on their armor as they rode into battle.
  10. During the Middle Ages diamonds were thought to have healing properties able to cure ailments ranging from fatigue to mental illness. 

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WHAT ARE MINERALS?

Minerals are natural chemicals from which Earth’s crust is formed. There are around 2000 individual minerals, each with a unique colour and shape. A few are powdery or resinous, but most are crystals. Some minerals, such as gold and silver, are pure chemical elements, but the majority are compounds, of which silicates are most common.

The earth is composed of mineral elements, either alone or in a myriad of combinations called compounds. A mineral is composed of a single element or compound. By definition, a mineral is a naturally occurring inorganic substance with a definite chemical composition and ordered atomic structure.

  • Table salt is a mineral called sodium chloride. Its ordered structure is apparent because it occurs in crystals shaped like small cubes.
  • Another common mineral is quartz, or silicon dioxide. Its crystals have a specific hexagonal shape. Coal is a mineral composed entirely of carbon, originally trapped by living organisms through the process of photosynthesis.
  • The carbon in coal is therefore of organic origin which leads some authorities to object to the definition of a mineral as an inorganic substance.
  • Limestone is a rock composed of a single mineral calcium carbonate. On the basis of their origin on earth rocks may be divided into three primary categories: igneous, sedimentary and metamorphic.

Minerals have been broadly classified into two classes, primary minerals and secondary minerals. Minerals which were formed by igneous process that is from the cooling down of the molten materials called magma, have been put in the primary category, while those formed by other processes have been put in the secondary category. Primary minerals which occur in the sand fractions of the soil had not undergone any change.

Other primary minerals had been altered to form the secondary minerals for example, the primary mineral mica had been altered to form the secondary mineral illite. Some other primary minerals for example, olivine, anorthite, hornblende etc., had been completely decomposed; the decomposition products recombined together to form the secondary minerals.

Minerals may be identified by their crystal structure, physical properties and chemical composition.

Like vitamins, minerals help your body grow, evolve and remain healthy. The body uses minerals to perform many functions — from building strong bones to nerve impulse transmission. Some minerals also create hormones or hold a regular heartbeat.

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ARE GEMS AND CRYSTALS THE SAME?

Crystals are glassy-looking, brittle solids that form shapes with sharp corners and flat sides. Natural crystals form when a liquid cools and hardens, and the molecules in the liquid cluster in a particular pattern – a pyramid, cube, etc.

Rare and beautiful crystals such as rubies and emeralds are valued as gems. Many are termed ‘precious’. They are rare because they only form naturally under very special conditions – usually deep within volcanic rocks.

Crystals are pure substances whose atoms, molecules, or ions are arranged in an ordered pattern, where they extend in all three spatial dimensions. A gem can be a crystal, while a crystal cannot be called as a gem.

Gemstone and Crystals are both used in various applications in today’s world. While gemstones are primarily used in jewelry and decoration pieces, crystals can be used in various applications such as healing, jewelry, vases, scientific purposes, etc.

Gemstones are rare pieces of minerals that are found in the ground, which are then cut and polished to be used in jewelry and other decorative pieces. Not all gems are minerals, such as lapis lazuli, a rock, and amber or jet, which are organic materials. A gemstone can also be known as precious or semi-precious stones. Precious stones include diamonds, emerald, ruby and sapphire, while the rest are qualified as semi-precious stones. Gemstones are classified by their color, translucency and hardness. Gems can also come with mineral bases like diamonds or rubies and with organic bases like amber. Today, geologists use the chemical composition of a gemstone to classify it into groups, species and varieties. The price of the gemstones depends on the rarity, color, composition, hardness and cut.

Crystals are pure substances whose atoms, molecules, or ions are arranged in an ordered pattern, where they extend in all three spatial dimensions. The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification. Not all crystals need to be in solid formation, where water freezing also begins with small ice crystals that grow. Crystal symmetry requires that the unit cells stack perfectly with no gaps. Crystals are classified as Hexagonal, cubic, orthorhombic, tetragonal, rhombohedral, and monoclinic shapes. Crystals are light in color and are mostly translucent. The color of crystal is determined by the light passing through it.  Crystals are less expensive compared to gemstones. Salt and snowflakes are the most common types of crystals that are encountered.

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WHAT ARE SILICATES?

When silicon and oxygen, the two most common chemical elements on Earth, combine with a metal, they forma silicate. There are over 500 silicates that exist, quartz is one.

Silicate mineral, any of a large group of silicon-oxygen compounds that are widely distributed throughout much of the solar system.

The silicates make up about 95 percent of Earth’s crust and upper mantle, occurring as the major constituents of most igneous rocks and in appreciable quantities in sedimentary and metamorphic varieties as well. They also are important constituents of lunar samples, meteorites, and most asteroids. In addition, planetary probes have detected their occurrence on the surfaces of Mercury, Venus, and Mars. Of the approximately 600 known silicate minerals, only a few dozen—a group that includes the feldspars, amphiboles, pyroxenes, micas, olivines, feldspathoids, and zeolites—are significant in rock formation.

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How many watts is a lightning strike?

Lightning is a natural electrical discharge created by imbalances between a cumulonimbus cloud and the ground or within itself. Lightning is pure electricity involving small particles with positive and negative charges that pull toward each other like the north and south ends of magnets. Lightnings are scary and of course dangerous, but it is a subject of fascination for scientists. During thunderstorms, scientists  witness a lot of lightning.  On an average, scientists have mapped, there are about 100 lightnings per second worldwide.That’s a whopping number. Imagine the amount of energy that’s shooting up from the clouds. Each bolt can contain up to one billion volts of electricity. This means a single lightning flash has enough energy to light a 100-watt bulb for three months!  So, How many homes could a lightning bolt power? Every lightning bolt on Earth in one year, captured perfectly with no loss of energy, would contain about 4*10^17 joules of energy. Thus, all the lightning in the entire world could only power 8% of US households. Human body can tolerate a maximum of between 20,000 and 50,000 volts, which might prove to be lethal. In most cases, a person’s heart will stop after being struck by lightning, so the key to survival is having someone nearby who can administer CPR. Even if you survive, a lightning strike will have long-lasting effects on your body, including memory issues, muscle soreness and changes in mood.

People often confuse lightning with thunder. To put it simply, lightning is electricity; thunder is sound. In other words, lightning is the sudden flash of light spotted in the sky, while thunder is the roaring, cracking sound that is commonly heard during thunderstorms. And because light travels faster than sound, lightning is seen before thunder can be heard.

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How heavy can clouds be?

Clouds are like light fluffy, white cotton candies on the sky. How much could they weigh? Our first guess would be “Since they float in the air, perhaps, close to nothing!” Well, we are wrong. Researchers have calculated that the average cumulus cloud weighs an incredible 5,00,000 kg. That’s a hundred elephants!

Clouds, after all, are made up of water, and water is quite heavy. The density of cumulus clouds is around 0.5 gram of water per cubic metre. A 1 cubic km cloud contains 1 billion cubic metre. Doing the math: 1,000,000,000 x 0.5 = 500,000,000 grams of water droplets in our cloud. That is about 5,00,000 kg or 1.1 million pounds (about 551 tonnes).

So now, the next question is, how does all this massive weight stay afloat in the sky? How come they don’t fall on our heads? Because the air below it is even heavier. That is, the density of the same volume of cloud material is less than the density of the same amount of dry air. Just as oil floats on water because it is less dense, clouds float on air because the moist air in clouds is less dense than dry air.

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Is Meghalaya the wettest place on Earth?

Mawsynram in Meghalaya is the wettest place, based on rainfall in the world. Located in the Khasi Hills, it receives about 11,872mm (nearly 467 inches) of average annual rainfall According to the Guinness Book of World Records, the region received 26,000mm of rainfall in 1985. The mountainous terrain of Mawsynram and the nearby Cherrapunji, the second wettest place, are known for their lush greenery and scenic beauty The “living bridges are one of the most beautiful features of this region. These have been created by the local people by training the roots of rubber trees into natural bridges. With the root systems constantly growing, these bridges are self-sustaining.

Primarily due to the high altitude, it seldom gets truly hot in Mawsynram. Average monthly temperatures range from around 11 °C in January to just above 20 °C in August. The village also experiences a brief but noticeably drier season from December until February, when monthly precipitation on average does not exceed 30 millimetres (1.2 in). The little precipitation during the village’s “low sun” season is something that is shared by many areas with this type of climate.

Three reasons can be cited for high rainfall at Mawsynram:

The warm moist winds of the northward-moving air from the Bay of Bengal during the monsoon, which cover an extensive area but are forced to converge into the narrower zone over the Khasi Hills, thus concentrating their moisture.
The alignment of the Khasi Hills (east to west) places them directly in the path of the airflow from the Bay of Bengal, producing a significant uplift (plus cooling, further condensation and thus more rain).
Finally, uplift over the Khasi Hills is virtually continuous in the monsoon period because the lifted air is constantly being pulled up by vigorous winds in the upper atmosphere; hence, the rainfall is more or less continuous.

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WHICH ROCKS ARE COMMONLY USED FOR BUILDINGS?

Many types of stones are available such as basalt, marble, limestone, sandstone, quartzite, travertine, slate, gneiss, laterite, and granite, which can be used as construction materials. The stones used for building construction should be hard, durable, tough, and should be free from weathered soft patches of material, cracks, and other defects that are responsible for the reduction of strength and durability. Stones for construction purposes are obtained by quarrying from massive solid rocks.

Each type of stone lends itself to various construction applications based on its properties. For instance, certain types like basalt and granite have superior characteristics like high compressive strength and durability and hence employed in major construction works. However, there are stones that their characteristic makes them suitable for minor construction works, for example, gneiss. So, stones are used as a building material and also for decorative purposes.

TYPES OF BUILDING STONES

Some of the common building stones which are used for different purposes in India are as follows:

GRANITE

It is a deep-seated igneous rock, which is hard, durable and available in various colours. It has a high value of crushing strength and is capable of bearing high weathering.

BASALT AND TRAP

They are originated from igneous rocks in the absence of pressure by the rapid cooling of the magma.

TRAP STONE

They have the same uses as granite. Deccan trap is a popular stone of this group in South India.

LIMESTONE

Limestone is used for flooring, roofing, pavements and as a base material for cement. It is found in Maharashtra, Andhra Pradesh, Punjab, Himachal Pradesh and Tamil Nadu.

SANDSTONE

This stone is another form of sedimentary rock formed by the action of mechanical sediments. It has a sandy structure which is low in strength and easy to dress.

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WHAT IS PUDDING STONE?

A mixture of different-sized pebbles cemented by sand, formed in river channels over thousands of years. It looks a bit like a Christmas pudding.

Puddingstone is a nonscientific name for a conglomerate in which subrounded to rounded pebbles occur in a matrix of sharply contrasting color.

The name “puddingstone” was first used in Great Britain where the rocks were said to “look like a plum pudding”. A well-known example is the Hertfordshire Puddingstone, from the lower Eocene of the London Basin. It consists of colorful flint pebbles in a white to brown silicate matrix. It is a rock found at many locations in Hertfordshire County, England.

Puddingstones immediately catch the eye of the geologist and the eyes of people who otherwise have no special interest in rocks. People have an immediate interest in the rocks and carry them home from beaches, streams, and wherever they are found.

Many particularly nice specimens find a place on desks, bookshelves, window sills and other locations where they will be seen by and delight even more people. Their popularity greatly exceeds their abundance.

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WHAT MAKES LIMESTONE INTERESTING?

Limestone is a sedimentary rock composed mainly of the mineral calcite, which is a crystalline form of Calcium Carbonate (CaCO3). Limestone often contains variable amounts of silica in the form of Jasper or Flint, as well as amounts of clay, silt, and sand as disseminations, nodules, or layers within the rock unit. The main source of this calcite in limestone is speleothems such as stalagmites and stalactites. The secondary source of calcite is the shells of sea animals and corals.

Limestone makes up about 10 percent of the total volume of all sedimentary rocks. Most Limestone starts as the floor of shallow tropical seas and can be seen in parts of the tropics that are only 30 to 40 years old. The stone has the unique property of retrograde solubility, meaning that the stone is less soluble in water as the temperature increases.

Limestone is also classified as a young marble formed from the consolidation of seashells and sediment. Shells of sea animals form grains in limestone that promotes the growth of cement crystals around themselves.

Limestone is a popular building material because of its availability and the relative ease with which it can be worked with and cut. The stone can have a very diverse chemical composition, which can result in a variety of different colours of limestone or even within a single cut of the stone.

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IS COAL A ROCK?

No. Although coal is sometimes called an organic rock, it is not a proper rock as rocks are inorganic (lifeless). Coal is a fossil fuel – like oil and gas- that formed over millions of years from the remains of once-living matter.

Coal is the largest source of energy for generating electricity in the world, and the most abundant fossil fuel in the United States.

Fossil fuels are formed from the remains of ancient organisms. Because coal takes millions of years to develop and there is a limited amount of it, it is a nonrenewable resource.

The conditions that would eventually create coal began to develop about 300 million years ago, during the Carboniferous period. During this time, the Earth was covered in wide, shallow seas and dense forests. The seas occasionally flooded the forested areas, trapping plants and algae at the bottom of a swampy wetland. Over time, the plants (mostly mosses) and algae were buried and compressed under the weight of overlying mud and vegetation.

As the plant debris sifted deeper under Earth’s surface, it encountered increased temperatures and higher pressure. Mud and acidic water prevented the plant matter from coming into contact with oxygen. Due to this, the plant matter decomposed at a very slow rate and retained most of its carbon (source of energy).

These areas of buried plant matter are called peat bogs. Peat bogs store massive amounts of carbon many meters underground. Peat itself can be burned for fuel, and is a major source of heat energy in countries such as Scotland, Ireland, and Russia.

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WHAT IS THE ROCK CYCLE?

Rocks are continually being recycled to make new rocks in a process called the rock cycle. For example, igneous rocks are gradually worn away by the weather. The weathered fragments are washed down to the sea and eventually form sedimentary rocks. Similarly, metamorphic rocks can be formed from both igneous and sedimentary rocks.

The rock components of the crust are slowly but constantly being changed from one form to another and the processes involved are summarized in the rock cycle. The rock cycle is driven by two forces: (1) Earth’s internal heat engine, which moves material around in the core and the mantle and leads to slow but significant changes within the crust, and (2) the hydrological cycle, which is the movement of water, ice, and air at the surface, and is powered by the sun.

The rock cycle is still active on Earth because our core is hot enough to keep the mantle moving, our atmosphere is relatively thick, and we have liquid water. On some other planets or their satellites, such as the Moon, the rock cycle is virtually dead because the core is no longer hot enough to drive mantle convection and there is no atmosphere or liquid water.

Magma is rock that is hot to the point of being entirely molten. This happens at between about 800° and 1300°C, depending on the composition and the pressure, onto the surface and cool quickly (within seconds to years) — forming extrusive igneous rock.

Magma can either cool slowly within the crust (over centuries to millions of years) — forming intrusive igneous rock, or erupt onto the surface and cool quickly (within seconds to years) — forming extrusive igneous rock. Intrusive igneous rock typically crystallizes at depths of hundreds of metres to tens of kilometres below the surface. To change its position in the rock cycle, intrusive igneous rock has to be uplifted and exposed by the erosion of the overlying rocks.

Through the various plate-tectonics-related processes of mountain building, all types of rocks are uplifted and exposed at the surface. Once exposed, they are weathered, both physically (by mechanical breaking of the rock) and chemically (by weathering of the minerals), and the weathering products — mostly small rock and mineral fragments — are eroded, transported, and then deposited as sediments. Transportation and deposition occur through the action of glaciers, streams, waves, wind, and other agents, and sediments are deposited in rivers, lakes, deserts, and the ocean.

Unless they are re-eroded and moved along, sediments will eventually be buried by more sediments. At depths of hundreds of metres or more, they become compressed and cemented into sedimentary rock. Again through various means, largely resulting from plate-tectonic forces, different kinds of rocks are either uplifted, to be re-eroded, or buried deeper within the crust where they are heated up, squeezed, and changed into metamorphic rock.

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HOW MANY TYPES OF ROCKS ARE THERE?

There are three kinds of rocks: igneous, sedimentary and metamorphic. Igneous rocks are formed when red-hot magma flows up from Earth’s hot core and cools down. Sedimentary rocks form when debris, including plant and organic matter, usually deposited on the seabed in layers, is built up, compressed and cemented into solid rock over millions of years. Metamorphic rocks are created when movements of Earth’s crust or the heat of its magma transforms one kind of rock into another.

Rocks are mineral aggregates with a combination of properties of all the mineral traces. Any unique combination of chemical composition, mineralogy, grain size, texture, or other distinguishing characteristics can describe rock types. Additionally, different classification systems exist for each major type of rock. There are different types of rocks existing in nature.

Rocks which are found in nature rarely show such simple characteristics and usually exhibit some variation in the set of properties as the measurement scale changes.

Types of Rocks

There are three types of rocks:

Igneous Rock

Igneous rock is one of the three main rock types. Igneous rock is formed through the cooling and solidification of magma or lava. Igneous rock may form with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.

Sedimentary Rock

The sedimentary rocks are formed by the deposition and subsequent cementation of that material within bodies of water and at the surface of the earth. The process that causes various organic materials and minerals to settle in a place is termed as sedimentation.

Metamorphic Rocks

The metamorphic rocks make up a large part of the Earth’s crust and are classified by texture and by chemical and mineral assemblage. They may be formed simply by being deep beneath the Earth’s surface, subjected to high temperatures and the great pressure of the rock layers above it.

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Does deserts ‘breathe’ water vapor?

Deserts are arid ecosystems, receiving fewer than 25 cm of precipitation a year. They are hot dry and deserted. But the sand dunes aren’t just inert masses. They, in fact. “breathe” water vapor and are very much alive. Scientists have developed a super-sensitive probe that has recorded how water vapor from the surrounding air percolate between sand grains.

Researchers at Cornell University, New York, and University of Nantes, France, developed over a decade a new form of instrumentation called capacitance probes. to study the moisture content in sand dunes to better understand the process by which agricultural lands turn to desert. The probe uses multiple sensors to record everything from solid concentration to velocity to water content, all with unprecedented spatial resolution. It is so sensitive to moisture that it can pick up tiny films of water on a single grain of sand!

Conducting the research at Qatar, they combined data on wind speed and direction as well as ambient temperature and humidity. The study revealed just how porous sand is, with a tiny amount of air seeping through it.

When wind flows over the dune, it creates imbalances in the local pressure. This forces air to go into and out of the sand. “So, the sand is breathing, like an organism breathes,” the researchers note. This breathing could be the reason behind how microbes live deep in sand dunes, even when no liquid water is available. The researchers also found that at the surface of the dune, the probe measured less evaporation than scientists were predicting. This shows that the leaching of moisture from the sand dune to the atmosphere is a slow chemical process.

The team’s paper has been published in the Journal of Geophysical Research-Earth Surface. Probes that can sensitively measure moisture within sand could help experts find invisible signs of water, say, on Mars.

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Six environmental issues and how to solve them?

Earth has undergone many environmental changes in its history. But the current ones are being caused by one species: humans. Our activities contribute to global warming, climate change, extreme weather events, species extinction, resource depletion, and what not. Let’s take a closer look at six of them to mark Earth Day, observed on April 22.

1. POLLUTION

Since the industrial revolution, environmental pollution has been on the rise. Pollution is the introduction of harmful contaminants into the environment that negatively alters our surroundings. While pollution can take several forms, such as light and noise, the three major types are air, land, and water pollution. Humans contribute to each of these every day. Pollution affects biodiversity, ecosystems, and human health worldwide. Air pollution is attributed to 11.65% of deaths globally, for instance. Vehicular and industrial emission, and basically, our dependence on fossil fuel for energy, is the chief cause of air pollution. While water pollution comes from sewage, chemicals, agricultural runoffs, etc. land pollution is caused by indiscriminate dumping of garbage, toxic materials, and industrial waste. Not to mention the harm caused by plastic pollution to marine and terrestrial life. As economies and population grow, pollution too increases at an alarming rate globally.

 2.GLACIER MELT AND SEA-LEVEL RISE

Nineteen of the warmest years in the recorded history of the planet has occurred since 2000. Models predict that as the world consumes more fossil fuel, greenhouse gas concentrations will continue to rise, and Earth’s average surface temperature will rise with them. Average surface temperatures could rise between 2°C and 6°C by the end of the 21st Century. A warmer atmosphere causes glaciers and polar ice sheets to melt rapidly. Glacial melt has a direct impact on freshwater flow because glaciers store water in the form of ice during the colder seasons and release it during warmer seasons by way of melting. This serves as a water source for humans, animals, and vegetation. Glacier melt also contributes to unusual rise in sea level. The impact of sea-level rise includes flooding of coastal areas, increased soil erosion, disappearance of some low-lying islands, saltwater intrusion, and habitat destruction in coastal areas, which, in turn, can affect coastal ecosystems.

What can you do?

A few tips on how we can reduce our impact on global warming: 1. Urge your parents to switch to renewable sources such as solar to power your home.

2. Use energy-efficient appliances at home and school

3. Support local businesses that use and promote sustainable, climate-smart practices

3. DEFORESTATION

Deforestation is the destruction of forests in order to make the land available for other uses. Earth loses 18.7 million acres of forests per year, which is equal to 27 football fields every minute, according to the World Wildlife Fund. Farmers clear forests to use the land for agriculture. Trees are cut for mining. for use as fuel. housing, and urbanisation, contruction of dams and infrastructual projects, and for making furniture. Deforestation is considered to be one of the contributing factors to global warming and climate change. Trees absorb not only the carbon dioxide that we exhale, but also the other heat-trapping greenhouse gases that human activities emit. With increase in deforestation, larger amounts of these gases will enter the atmosphere and global warming will increase further. As much as 70 % of the world’s plants and animals live in forests. They are losing their habitats due to deforestation. Loss of habitat can lead to species extinction.

What can you do?

1. Plant saplings

2. Go paperless

3. Go for used-furniture instead of buying new ones every time.

4.WATER CRISIS

If global temperatures continue to rise, rainfall will increasingly become a thing of extremes: long dry spells here. dangerous floods there and in some places, intense water shortages. This will also affect agriculture. Worldwide, farmers are struggling to keep up with shifting weather patterns and increasingly unpredictable water supplies. Extreme weather patterns also destroy life, property. and livelihood. The rapid increase in population and the massive growth in the industrial sector have increased the demand for water multifold. Overexploitation and wastage of water are major issues, especially in urban areas. A UN report says that at least two billion people live in countries with high water stress. That is more than a quarter of the world population. Ecosystems and biodiversity are threatened by the scarcity of water resources. Water crisis can also lead conflict between States that share water sources such as river.

What can you do?

1. Do not waste water

2. Fix leaking tap and try to reuse water wherever possible

3. Urge your parents to install rainwater harvesting facility

4. Don’t pollute water: Do not dump household solid waste or oil and chemicals into the drainage system. Do not litter. They are likely to end up in a waterbody.

5.WILDFIRE

As warmer temperatures increase evaporation, the land becomes drier and drier, enhancing the chances of wildfires. The intense, destructive fires that have dominated headlines in recent years are expected to become more frequent, even in places such as the Arctic. Extreme fires are projected to rise up to 14% by 2030 and 30% by mid-century, according to a new report by the UN Environment Programme.

Wildfires not only destroy forests and cause loss of life, they emit large amounts of greenhouse gases such as CO2, methane, and carbon monoxide. The smoke from burning vegetation can pose serious risks to respiratory health. Animals are directly impacted by wildfire. They lose their life or their home and food source.

What can you do?

1. Build your campfire in an open location and far from flammables

2. Do not contribute to global warming

3. Avoid burning wastes around dry grass.

6. WILDLIFE TRADE

Wildlife trade is a big business, run by international networks. Animals and birds are trafficked across the globe for meat, skin, bone, fur, and other body parts. In addition, many species are sold as pets. Experts at TRAFFIC, the wildlife trade monitoring network, estimate that the illegal wildlife commerce runs into billions of dollars. Wildlife trafficking threatens the survival of some of the Earth’s most iconic species: tiger, elephant, rhinoceros, pangolin, etc. It affects food chain and threatens the local ecosystem. Wildlife trade also increases the chances of human-animal contact, putting humans at the risk of contracting diseases. COVID-19 was linked to wildlife trade and eating of wildlife. People who handled, killed, and sold wild animals made up nearly 40 % of the first cases of SARS. Poorly regulated wet markets and illegal wildlife trade offer a unique opportunity for viruses to spill over from wildlife hosts into the human population.

What can you do?

1. Create awareness among the public about wildlife trade.

2. Say no to exotic pets. They may have been trafficked and kept in unsafe conditions before being sold.

3. Avoid buying things made from ivory, horns, and leather. This discourages illegal trading.

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