Category Earth Science

What is the career in the field of Earth Sciences?

Our Earth is extremely fragile, and human activities are making it more vulnerable. One of the recent examples of the impact of indiscriminate development and climate change is the shocking collapse of a portion of the Nanda Devi glacier in Uttarakhand’s Chamoli district on February 7, 2021, and the ensuing floods that claimed many lives. The deadly disaster brings to light the need to rigorously study the impact of human activity on the environment. And that’s exactly what earth scientists do.

What is Earth Science?

Earth science is the study of the structure, composition, and evolution of the Earth, the life it supports, and the processes that govern the formation and behaviour of the Earth’s materials. It seeks to find answers to questions such as how ice moves, where the mineral resources are, and the rate of permafrost thaw. Understanding these phenomena is essential to the maintenance of life on the planet.

Different branches:

  • Glaciology: Glaciologists assess the impact of climate change, look for alternatives to sustain Earth’s depleting resources, and forecast avalanches.
  • Geology: Geologists study Earth and the processes that act on its materials. It also traces the history of the planet and its life forms since origin.
  • Hydrogeology: The study of water flow on and below the Earth’s surface and its chemistry.
  • Limnology: Limnology examines lake sediments to determine past climate and ecological environments.
  • Oceanography: The study of the ocean, including its water, boundaries and topography, types of currents, and marine biology.
  • Volcanology and Seismology: The scientific study of the dynamics of volcanoes and earthquakes.

What to study?

Universities in India and abroad offer a range of courses in Earth Sciences. You can pursue a Master of Science (M.Sc) and specialise in the field of your choice. A Ph.D is required to start working in the field.

Where: India

  • Wadia Institute of Himalayan Geology, Dehradun: Training and research programmes on Geomorphology and Environmental Geology. Geophysics, Petrology and Geochemistry
  • Indian Institute of Science Education and Research, Pune: Dual degree programme Bachelor of Science and Master of Science
  • Sharada University. Noida, and Pondicherry University: M.Sc in Environmental Sciences
  • Bharatiya Vidyapeeth, Insitute of Environment Education and Research. Punes M.Sc in Environment Science and Technology
  • Annamalai University, Cuddalore: M.Sc Earth Sciences and PG diplomas in Petroleum and Remote Sensing


  • Utrecht University, the Netherlands, M.Sc Earth Surface and Water
  • University of Helsinki, Finland: M.Sc Geology and Geophysics
  • The University of Westent Australia: Master of Geographic Information Science
  • Massachusetts Institute of Technology, the U.S. M.SC Atmospheres, Oceans and Climate: M.Sc Geology, Geochemistry and Geobiology; Master of Environmental Policy and Planning

What are the job prospects?

Earth scientists primarily work in research organisations and environmental monitoring agencies.

These organisations could be in the private as well as the public sector.

Depending on your field of interest, you can also work with non-profit organisations and think-tanks on environment conservation and policy. If you have an academic bent of mind, then working in a university as a professor in the field of your choice could also suit you.


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What is GPS map?

This accurate, up-to-date map is created using digital technology. You can view GPS maps on your phone, tablet, or computer. They can tell you exactly where you are at any time. The coordinates and position as well as atomic time obtained by a terrestrial GPS receiver from GPS satellites orbiting Earth interact together to provide the digital mapping programming with points of origin in addition to the destination points needed to calculate distance. This information is then analyzed and compiled to create a map that provides the easiest and most efficient way to reach a destination.

More technically speaking, the device operates in the following manner:

  • GPS receivers collect data from at least four GPS satellites orbiting the Earth, calculating position in three dimensions.
  • The GPS receiver then utilizes position to provide GPS coordinates, or exact points of latitudinal and longitudinal direction from GPS satellites.
  • The points, or coordinates, output an accurate range between approximately “10-20 meters” of the actual location.
  • The beginning point, entered via GPS coordinates, and the ending point, (address or coordinates) input by the user, are then entered into the digital mapping software.
  • The mapping software outputs a real-time visual representation of the route. The map then moves along the path of the driver.
  • If the driver drifts from the designated route, the navigation system will use the current coordinates to recalculate a route to the destination location.


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What is political world map?

A political map shows you the countries of the world. You see where borders and cities are, including national capitals. Imaginary, numbered lines- the equator and lines of latitude and longitude – give you the exact position on Earth of places they pass through. Some of the largest independent nations in the world are the Russian Federation, People’s Republic of China, the United States of America, Canada, Australia, India, Brazil, Saudi Arabia, and Argentina. While the smallest nations include Vatican City, Monaco, Andorra, and Singapore.

As represented on the world map, some countries like Brazil, Australia, the USA, and Indonesia have long coastlines, while others are completely landlocked like Bhutan, Switzerland, Mongolia, and Lesotho.

The world political map shows dependent territories such as Greenland and the Faroe Islands of Denmark, as well as the French Overseas Territories, which are geographically and culturally distinct, enjoying some degree of autonomy but are not independent states.


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What is street map?

This type of map shows where the streets and roads in a town or city are. It will also show bus stops, stations, schools, hospitals, parks, and other useful and important places. The maps are of different sizes, shapes, and scales. Small maps are used to show the overview of a region’s major roads or routes while large maps give greater details and cover a large area. Highway maps give the overview of major routes within a region. Street maps mainly cover areas within a city or metropolitan area. A collection of road maps bound together in a book is referred to as road atlas. Road maps often use thin lines to indicate minor roads and thicker or bolder colors to indicate major roads.


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What is physical map?

This type of map shows you the natural features in an area. These include mountains, volcanoes, rivers, lakes, seas, oceans, and deserts. Different colours and symbols are used to represent these features.


The physical land mass of the world, the planet Earth, is divided into seven continents of Africa, North America, South America, Europe, Australia, Asia and Antarctica (It being the only uninhabited continent) . Asia with 29% of the world land mass is the largest and Australia with 5.9% of landmass the smallest. Mount Everest is the highest point on earth and Dead Sea the lowest.


Deserts occupy about 33% of the world land mass. Deserts, places on earth which have very little rainfall, can be either hot or cold. The largest cold deserts are the polar deserts of Antarctica and Arctic Circle. The largest sub tropical or hot deserts are the Sahara and Arabian Desert. Gobi and Kalahari are other large deserts.

Mountain ranges:

Mountains cover 24% of the earth land mass and are spread over all the continents. Asia has the largest area covered with mountains and Africa the least- only 3%. Himalayas, the Earth’s youngest mountains are also the highest. These mountains are still growing. Mount Everest at 8848 meters is the highest peak and K2 at 8611 meters, the second highest. Alps are the mountain ranges in Europe and Rockies in North America.


Over two-third of the Earth’s surface is covered with water and more than 97% of this water is contained in the oceans. The Pacific Ocean is the largest and deepest ocean in the world. The other oceans are Atlantic, Indian, Pacific, Southern and Arctic.


The earth is dotted with lakes-bodies of fresh or salt water surrounded by a land mass. Northern hemisphere has the majority of fresh water lakes. Aral Sea, Dead Sea, and Great Salt Lake are salt water lakes. Caspian Sea, if considered as a lake is the largest. Other large lakes are Lake Michigan in North America, Lake Victoria in Africa, and Lake Eyre in Australia.


Rivers are watercourses flowing towards oceans, seas, lakes or another river. The Nile River, in Africa, with a length of 6695 kilometers is the longest in the world. The Brahmaputra and the Ganges are rivers in Asia. The Colorado and the Mississippi are rivers in North America. The Amazon, the second largest river, is in South America. River Congo, in Africa is the deepest river though it is the ninth longest.


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What are urban areas?

An urban area is the region surrounding a city. Most inhabitants of urban areas have non agricultural jobs. Urban areas are very developed, meaning there is a density of human structures such as houses, commercial buildings, roads, bridges, and railways.

“Urban area” can refer to towns, cities, and suburbs. An urban area includes the city itself, as well as the surrounding areas. Many urban areas are called metropolitan areas, or “greater,” as in Greater New York or Greater London.

When two or more metropolitan areas grow until they combine, the result may be known as a megalopolis. In the United States, the urban area of Boston, Massachusetts, eventually spread as far south as Washington, D.C., creating the megalopolis of BosWash, or the Northeast Corridor.


Settlement refers to the physical spaces and environments in which households are sheltered, and how one shelter relates to others. The term is generally used in the context of displaced populations to describe the temporary or sometimes permanent living arrangements of displaced families. In this context settlements can range from planned camps to dispersed accommodation in host villages/neighbourhoods, collective centres, spontaneous camps, rental accommodation, etc.

An urban settlement is where displaced populations settle within an urban agglomeration such as a town or city. A master plan usually divides towns or cities into zones regulated by norms based on specific sectors such as housing, hygiene, habitat, and environment. Zones are inclusive of residential areas, services and infrastructures, and spaces for administrative, commercial and industrial activities.


Usually, there are lots of shops, schools, libraries, and hospitals. There may also be sports centres and swimming pools. The land uses and buildings that are used to serve the educational purposes of the community. These facilities very often have a secondary function of providing a location for social and recreational activities of the community. Health category of urban object includes all facilities where medical treatment of some form is offered. For example, it would include a local GP clinic or a city hospital. This category is, however, not limited to clinical or medical healthcare, it includes all object related to the diagnosis, treatment and rehabilitation of people with sickness or illness. Buildings and facilities relating to government departments or entities. This would include, for example administration office associated with a government department or agency, police and fire services stations, etc. For the purposes of Urban Securipedia, government assets do not extend to recreational services or utilities such as water/waste/energy infrastructure or facilities.


In many countries, most of the populations now live in towns and cities. This is because there are plenty of jobs and houses there. In the mid 1800s, only 2% of the entire human population lived in urban areas. By the 1950’s, the percentage of the human population living in urban areas was up to around 29%, and by 2009, that number had reached 50%. This number is expected to increase rapidly and by 2050, it is predicted that over 70% of the human population will live in urban areas.


 Most towns and cities have good transport links. These include roads for buses and cars, railways, and airports. Travel is necessary to engage in spatially dispersed activities such as work, shopping, visits to friends, etc. In economic terms, travel is an intermediate good, because demand for travel is derived from the demand for other spatially separated goods and services. Thus, one travels in order to engage in work or to do shopping or see a film. Apart from sightseeing and some types of holiday, rarely do people travel simply for the sheer pleasure of the trip.


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What are rural areas?

A rural area is an open swath of land that has few homes or other buildings, and not very many people. 

A rural areas population density is very low. Many people live in a city, or urban area. Their homes and businesses are located very close to one another. In a rural area, there are fewer people, and their homes and businesses are located far away from one another.

Agriculture is the primary industry in most rural areas. Most people live or work on farms or ranches. Hamlets, villages, towns, and other small settlements are in or surrounded by rural areas. 

Wildlife is more frequently found in rural areas than in cities because of the absence of people and buildings. In fact, rural areas are often called the country because residents can see and interact with the country’s native wildlife.

Throughout the world, more people live in rural areas than in urban areas. This has been changing rapidly, however. Urbanization is happening all over the world. In Asia, for example, the United Nations estimates that the urban population will increase by almost 2 billion by 2050. 

Open spaces:

These are common in rural areas. Some are conservation areas that are specially protected. The purpose of an open space reserve may include the preservation or conservation of a community or region’s rural natural or historic character; the conservation or preservation of a land or water area for the sake of recreational, ecological, environmental, aesthetic, or agricultural interests; or the management of a community or region’s growth in terms of development, industry, or natural resources extraction.


Rural areas often have few or no shops, hospitals, or post offices. Peoples may have to travel to the city to find them. People in rural areas generally have less access to healthcare than their urban counterparts. Fewer medical practitioners, mental health programs and healthcare facilities in these areas often mean less preventative care and longer response times in emergencies. The lack of healthcare workers has resulted in unconventional ways of delivering healthcare to rural dwellers, including medical consultations by phone or internet as well as mobile preventative care and treatment programs. There have been increased efforts to attract health professionals to isolated locations, such as increasing the number of medical students from rural areas and improving financial incentives for rural practices.


Settlement refers to the physical spaces and environments in which households are sheltered, and how one shelter relates to others. The term is generally used in the context of displaced populations to describe the temporary or sometimes permanent living arrangements of displaced families. In this context settlements can range from planned camps to dispersed accommodation in host villages/neighbourhoods, collective centres, and spontaneous camps, etc.

A rural settlement is where displaced populations settle on land outside of cities and towns. The population is often dependent on agricultural and pastoral practices, and has fewer community infrastructure systems than in urban settlements.


A lot of the land in rural areas is used for growing crops and rearing animals for food. In rural areas throughout the world, agriculture represents the predominant land use and a major component of the viability of rural areas. Farming and related activities make up the basic fabric of rural life, contributing significantly to the overall state of rural regions in terms of employment and business opportunities, infrastructure and quality of the environment.


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What are the uses of rocks?

Rocket and minerals make up much of our planet. They are formed deep inside the Earth over millions of Years. Rocks exist in lots of different shape, textures, and colours. They are mined to provide any of the things around us. Can you guess which rock is used where?


Granite is and igneous rock which has extremely good weathering properties because it is very hard. This hardness makes it relatively difficult to work. Granite has been used in a large number of important buildings in the UK including Truro Cathedral, London Tower Bridge, Parts of St Pauls Cathedral, and Nelson’s Column. Granite has been mostly mined in the South West of England (Devon and Cornwall and in Aberdeenshire. Aberdeen is called the Granite City.

Iron ore:

Earth’s most important iron ore deposits are found in sedimentary rocks. They formed from chemical reactions that combined iron and oxygen in marine and fresh waters. The two most important minerals in these deposits are iron oxides: hematite (Fe2O3) and magnetite (Fe3O4). These iron ores have been mined to produce almost every iron and steel object that we use today – from paper clips to automobiles to the steel beams in skyscrapers.


Turquoise is an opaque mineral that occurs in beautiful hues of blue, bluish green, green, and yellowish green. It has been treasured as a gemstone for thousands of years. Isolated from one another, the ancient people of Africa, Asia, South America and North America independently made turquoise one of their preferred materials for producing gemstones, inlay, and small sculptures.

 Rock salt:

Rock Salt is a chemical sedimentary rock that forms from the evaporation of ocean or saline lake waters. It is also known by the mineral name “halite”. It is rarely found at Earth’s surface, except in areas of very arid climate. It is often mined for use in the chemical industry or for use as a winter highway treatment. Some halite is processed for use as a seasoning for food. 


Marble is a metamorphic rock that forms when limestone is subjected to the heat and pressure of metamorphism. It is composed primarily of the mineral calcite (CaCO3) and usually contains other minerals, such as clay minerals, micas, quartz, pyrite, iron oxides, and graphite. Under the conditions of metamorphism, the calcite in the limestone recrystallizes to form a rock that is a mass of interlocking calcite crystals. A related rock, dolomitic marble, is produced when dolostone is subjected to heat and pressure.


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What are the types of rocks?

There are three different groups of rock: igneous, sedimentary, and metamorphic. Rocks are classified into these three different groups, depending on how they were formed.

Igneous rock:

Igneous rocks (from the Greek word for fire) form from when hot, molten rock crystallizes and solidifies. The melt originates deep within the Earth near active plate boundaries or hot spots, then rises toward the surface. Igneous rocks are divided into two groups, intrusive or extrusive, depending upon where the molten rock solidifies.

Intrusive Igneous Rocks:
Intrusive, or plutonic, igneous rock forms when magma is trapped deep inside the Earth. Great globs of molten rock rise toward the surface. Some of the magma may feed volcanoes on the Earth’s surface, but most remains trapped below, where it cools very slowly over many thousands or millions of years until it solidifies. Slow cooling means the individual mineral grains have a very long time to grow, so they grow to a relatively large size. Intrusive rocks have a coarse grained texture.

Extrusive Igneous Rocks:
Extrusive, or volcanic, igneous rock is produced when magma exits and cools above (or very near) the Earth’s surface. These are the rocks that form at erupting volcanoes and oozing fissures. The magma, called lava when molten rock erupts on the surface, cools and solidifies almost instantly when it is exposed to the relatively cool temperature of the atmosphere. Quick cooling means that mineral crystals don’t have much time to grow, so these rocks have a very fine-grained or even glassy texture. Hot gas bubbles are often trapped in the quenched lava, forming a bubbly, vesicular texture.

Sedimentary rock:

Sedimentary rock is one of the three main rock groups (along with igneous and metamorphic rocks) and is formed in four main ways: by the deposition of the weathered remains of other rocks (known as ‘clastic’ sedimentary rocks); by the accumulation and the consolidation of sediments; by the deposition of the results of biogenic activity; and by precipitation from solution.

Sedimentary rocks include common types such as chalk, limestone, sandstone, clay and shale.

Sedimentary rocks cover 75% of the Earth’s surface.

Four basic processes are involved in the formation of a clastic sedimentary rock: weathering (erosion) caused mainly by friction of waves, transportation where the sediment is carried along by a current, deposition and compaction where the sediment is squashed together to form a rock of this kind.

Sedimentary rocks are formed from overburden pressure as particles of sediment are deposited out of air, ice, or water flows carrying the particles in suspension.

As sediment deposition builds up, the overburden (or ‘lithostatic’) pressure squeezes the sediment into layered solids in a process known as lithification (‘rock formation’) and the original connate fluids are expelled.

The term diagenesis is used to describe all the chemical, physical, and biological changes, including cementation, undergone by sediment after its initial deposition and during and after its lithification, exclusive of surface weathering.

Metamorphic rock:

Metamorphic rocks are rocks that have become changed by intense heat or pressure while forming. In the very hot and pressured conditions deep inside the Earth’s crust, both sedimentary and igneous rocks can be changed into metamorphic rock. In certain conditions these rocks cool and crystallize usually into bands of crystals. Later they can become exposed on Earth’s surface. One way to tell if a rock sample is metamorphic is to see if the crystals within it are arranged in bands.

One way to think about the metamorphic process (metamorphism) is to consider what happens when soft clay objects are put into a kiln and heated to a very high temperature. They change from being squashy to rock hard. They cannot be changed back to their original form. The material has been changed. This is what happens on a huge scale underground producing metamorphic rock.


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What are the seven continents of the world?

All of the land on Earth is divided up into seven large areas, called continents. These are North America, South America, Europe, Africa, Asia, Australia, and Antarctica. Each continent is divided u p again into a number of different countries.

North America:

This is the third largest continent, and has the fourth-largest population. North America runs from the America runs from the Arctic down to the equator, so the climate varies a lot.

North America occupies the northern portion of the landmass generally referred to as the New World, the Western Hemisphere, or simply the Americas. Mainland North America is shaped roughly like a triangle, with its base in the north and its apex in the south; associated with the continent is Greenland, the largest island in the world, and such offshore groups as the Arctic Archipelago, the West Indies, Haida Gwaii (formerly the Queen Charlotte Islands), and the Aleutian Islands.

South America:

South America, fourth largest of the world’s continents. It is the southern portion of the landmass generally referred to as the New World, the Western Hemisphere, or simply the Americas. The continent is compact and roughly triangular in shape, being broad in the north and tapering to a point—Cape Horn, Chile—in the south.

South America is bounded by the Caribbean Sea to the northwest and north, the Atlantic Ocean to the northeast, east, and southeast, and the Pacific Ocean to the west. In the northwest it is joined to North America by the Isthmus of Panama, a land bridge narrowing to about 50 miles (80 km) at one point. Drake Passage, south of Cape Horn, separates South America from Antarctica.


Antarctica, fifth in size among the world’s continents. Its landmass is almost wholly covered by a vast ice sheet.

Lying almost concentrically around the South Pole, Antarctica—the name of which means “opposite to the Arctic”—is the southernmost continent, a circumstance that has had momentous consequences for all aspects of its character. It covers about 5.5 million square miles (14.2 million square km), and would be essentially circular except for the outflaring Antarctic Peninsula, which reaches toward the southern tip of South America (some 600 miles [970 km] away), and for two principal embayments, the Ross Sea and the Weddell Sea. These deep embayments of the southernmost Pacific and Atlantic oceans make the continent somewhat pear-shaped, dividing it into two unequal-sized parts. The larger is generally known as East Antarctica because most of it lies in east longitudes. The smaller, wholly in west longitudes, is generally called West Antarctica. East and West Antarctica are separated by the approximately 2,000-mile- (3,200-km-) long Transantarctic Mountains. Whereas East Antarctica consists largely of a high ice-covered plateau, West Antarctica consists of an archipelago of mountainous islands covered and bonded together by ice.


Europe, second smallest of the world’s continents, composed of the westward-projecting peninsulas of Eurasia (the great landmass that it shares with Asia) and occupying nearly one-fifteenth of the world’s total land area. It is bordered on the north by the Arctic Ocean, on the west by the Atlantic Ocean, and on the south (west to east) by the Mediterranean Sea, the Black Sea, the Kuma-Manych Depression, and the Caspian Sea. The continent’s eastern boundary (north to south) runs along the Ural Mountains and then roughly southwest along the Emba (Zhem) River, terminating at the northern Caspian coast.

Europe’s largest islands and archipelagoes include Novaya Zemlya, Franz Josef Land, Svalbard, Iceland, the Faroe Islands, the British Isles, the Balearic Islands, Corsica, Sardinia, Sicily, Malta, Crete, and Cyprus. Its major peninsulas include Jutland and the Scandinavian, Iberian, Italian, and Balkan peninsulas. Indented by numerous bays, fjords, and seas, continental Europe’s highly irregular coastline is about 24,000 miles (38,000 km) long.


Africa, the second largest continent (after Asia), covering about one-fifth of the total land surface of Earth. The continent is bounded on the west by the Atlantic Ocean, on the north by the Mediterranean Sea, on the east by the Red Sea and the Indian Ocean, and on the south by the mingling waters of the Atlantic and Indian oceans.

Africa’s total land area is approximately 11,724,000 square miles (30,365,000 square km), and the continent measures about 5,000 miles (8,000 km) from north to south and about 4,600 miles (7,400 km) from east to west. Its northern extremity is Al-Gh?r?n Point, near Al-Abya? Point (Cape Blanc), Tunisia; its southern extremity is Cape Agulhas, South Africa; its farthest point east is Xaafuun (Hafun) Point, near Cape Gwardafuy (Guardafui), Somalia; and its western extremity is Almadi Point (Pointe des Almadies), on Cape Verde (Cap Vert), Senegal. In the northeast, Africa was joined to Asia by the Sinai Peninsula until the construction of the Suez Canal. Paradoxically, the coastline of Africa—18,950 miles (30,500 km) in length—is shorter than that of Europe, because there are few inlets and few large bays or gulfs.


Australia is a continent in the Southern Hemisphere, which comprises the countries of Australia, Tasmania, Seram, New Guinea, Timor, and other neighbouring islands. It is the smallest among the seven continents of the world, and lies on a continental shelf. Shallow seas divide the continent in to the different landmasses. The Torres Strait and Arafura Sea separate the mainland of Australia and New Guinea, and the Bass Strait lies between Tasmania and mainland Australia. They were actually connected by dry land in earlier times during the time around 18,000 BC, when the sea levels were lower. It was the Pleistocene ice age then. The sea levels have risen in the past ten thousand years, and that overflowed the lands and separated the different landmasses. New Zealand is not a part of the continent of Australia, but of the separate continent of Zealandia which is submerged. Both New Zealand and Australia are parts of the wider regions well known by Oceania or Australasia.


Asia, the world’s largest and most diverse continent. It occupies the eastern four-fifths of the giant Eurasian landmass. Asia is more a geographic term than a homogeneous continent, and the use of the term to describe such a vast area always carries the potential of obscuring the enormous diversity among the regions it encompasses. Asia has both the highest and the lowest points on the surface of Earth, has the longest coastline of any continent, is subject overall to the world’s widest climatic extremes, and, consequently, produces the most varied forms of vegetation and animal life on Earth. In addition, the peoples of Asia have established the broadest variety of human adaptation found on any of the continents.Africa: This is the second-largest continent and has the most countries. The world’s longest river and the world’s largest desert are in Africa.


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