Explanation: Isochrones. Isohaline – A line drawn on a map to indicate connecting points of equal salinity in the ocean. Isonomal – A line on a chart connecting points of equal abundance values of a plant species sampled in different sections of an area. Isobronts – A line drawn through geographical points at which a given phase of thunderstorm activity occurred simultaneously.

Explanation: Parallels of Latitude. The parallels of latitude refer to the angular distance, in degrees, minutes and seconds of a point north or south of the Equator.

Explanation: Itanagar (capital of Arunachal Pradesh). Other State Capital Latitude and Longitude – Patna (25 North, 85 East), Dispur (26 North, 91 East), Hyderabad (17 North, 78 East).

Explanation: i-c, ii-b, iii-a, iv-d. Abundances of other Element in the Earth’s Crust: Calcium (Ca) – 3.63%, Sodium (Na) – 2.83%, Potassium (K) – 2.59%, Magnesium (Mg) – 2.09% and others – 1.41%. Earth has three layers: crust (upper layer), mantle (middle layer), and core (lower layer).

Explanation: 1° or even less. The Continental Shelf is the extended margin of each continent occupied by relatively shallow seas and gulfs. About Continental Shelf : The shelf typically ends at a very steep slope, called the shelf break. Their width varies globally, with an average of about 80 km, but can be narrower or even absent in some regions, such as the coasts of Chile and the west coast of Sumatra.

Explanation: January. Perihelion – It is the point of the Earth’s orbit that is nearest to the Sun. This always happens in early January about two weeks after the December Solstice. Aphelion – It is the point of the Earth’s orbit that is farthest away from the Sun. It always happens in early July about two weeks after the June solstice.

Explanation: Pangea. Alfred Wegener propounded Continental Drift Theory in 1912. He proposed that the continents were once united into a single supercontinent called Pangaea (meaning all earth). The evidence in support of the continental drift theory: Jigsaw Fit, Geological Fit, Tectonic Fit, Glacial Deposits, Fossil Evidence.

Explanation: 80%. Taking Earth’s age as nearly 4.6 Billion Years (BY), instead of 13.7 BY from the Big Bang, unicellular life appeared nearly 3.8 BY ago. This percentage is 3.8/4.6 X 100 = 82.6%, nearly.

Explanation: a and b. Continentality – Found in inland areas. It is very hot during summers and very cold during winters. Continental climates are common between 40° and 70° north latitude and experience large temperature differences between day and night.

Explanation: Indian ocean is the only ocean in the world which has been named after a country. The Indian Ocean bridges the gap between East and the West. The Western and Eastern parts are known as the Arabian Sea and Bay of Bengal. Pacific Ocean – Largest and deepest ocean in the world.

Explanation: Hot water current. The term El Nino (Little Boy in Spanish) – Warming of the ocean surface, or above-average sea surface temperatures, in the central and eastern tropical Pacific Ocean on the coast of Peru. El nino leads to weakening of trade winds in a region. La Nina (Little Girl in Spanish) – The periodic cooling of ocean surface temperatures in the central and east-central equatorial Pacific.

Explanation: Pacific Ocean (world’s largest and deepest ocean): It represents 45 percent of the global ocean surface. The International Date Line (established in 1884) passes through the mid-Pacific Ocean. Atlantic Ocean (S – shaped) : Deepest trench – Puerto Rico; The Sargasso sea, the only sea in the world without any shore (land boundary), is present in the Atlantic ocean. Indian Ocean (the warmest) : Deepest trench – Sunda (or Java trench). The Antarctic Ocean (Southern Ocean) is known for its turbulent waters.

Explanation: Atlantic Ocean is the 2nd largest ocean in the world. The Mediterranean is an intercontinental sea spread between Europe, North Africa, and Western Asia and connected to the Atlantic Ocean through the strait of Gibraltar. Indian Ocean – 3rd largest Ocean in the world. Pacific Ocean – Largest ocean in the world. Arctic Ocean – Smallest ocean in the world.

Explanation: Earth’s crust and the mantle. Moho discontinuity – It occurs at an average depth of about 8 kilometers beneath the ocean basins and 32 kilometers beneath continental surfaces.

Explanation: Tide: Forms when there is an increase or decrease in the sea level that happens periodically because of the gravitational force of the moon and sun. Types of Tides: Tides Based on Frequency – Semi-Diurnal Tides, Diurnal Tides, Mixed. Tides Based on the Position of Earth, Sun, and the Moon – Spring Tides, Neap Tides.

Explanation: Two. When the Earth, Sun, and Moon line up, their gravitational power combines to make exceptionally high tides where the bulges occur, called spring tides, as well as very low tides where the water has been displaced. When the Sun is at a right angle to the Moon, moderate tides, called neap tides. There are generally three types of tides: Diurnal – One high and low tide each day, Semi-diurnal – Two high and low tides each day, and Mixed – Two high and low tides each day of different heights.

Explanation: Above. Salinity is the measure of the amount of dissolved salts in water. Evaporation of ocean water and formation of sea ice both increase the salinity of the ocean. Lake Van of Turkey has the highest salinity in the world at 330 %. The saltiest ocean water is in the Red Sea and in the Persian Gulf region (around 40 ppt) due to very high evaporation. Freshwater from rivers has a salinity value of 0.5 ppt or less.

Explanation: Pacific Ocean (the world’s largest) : The name was given by Ferdinand Magellan; The International Date Line passes through the Pacific Ocean.

Explanation: The Oceanic Slope. Continental Shelf – Extends from the coastline of a continent to a drop-off point called the shelf break. Continental Slope – From the break, the shelf descends toward the deep ocean floor. The Deep Sea Plain (Abyssal plain) is an underwater plain on the deep ocean floor, usually found at depths between 3,000 meters and 6,000 meters. Trenches (The ocean deeps) are prominent long, narrow topographic depressions of the ocean floor

Explanation: Pacific Ocean – largest ocean on the Earth. It occupies one-third of the earth’s surface. It separates Asia and Australia from North America and South America.

Explanation: Bering. Bosphorus strait is a natural strait, located in northwestern Turkey, connecting the Black Sea to the Sea of Marmara. Hudson Strait links the northern seaports of Manitoba and Ontario with the Atlantic Ocean. Palk Strait is a strait between India and Sri Lanka. It connects the Bay of Bengal in the northeast with the Gulf of Mannar in the southwest.

Explanation: Asia. It is the largest (30% of the Earth’s land area) and most populous (60% of the total population) continent. Asia is the biggest producer (90% of the world’s production) of rice. About 30% of the world’s reserves of iron ore are found in Asia. Biggest producer of tin (in the world) – China. Leading tin producing state in India – Chhattisgarh.

Explanation: Ocean currents are the continuous, predictable, directional movement of seawater driven by gravity, wind (Coriolis Effect), and water density. Largest ocean current on Earth: Antarctic Circumpolar Current (ACC).

Explanation: 97.2 percent. Water covers 71 percent of Earth’s surface. Distribution of Earth’s water: Oceans (97.2%), Glaciers (2.1%), Groundwater (0.61 percent); Freshwater lakes (0.009 percent), Inland seas (0.008 percent), Soil Moisture (0.005 percent), Atmosphere (0.001 percent), Rivers (0.0001 percent).

Explanation: 10 to 200 km. The lithosphere is the outermost and mechanical layer of the Earth that consists of the entire crust and the top-most portion of the mantle. Mechanically, the earth’s layers can be divided into lithosphere, asthenosphere (80-200 km), mesospheric mantle , outer core, and inner core.

Explanation: 7. A tectonic plate (lithospheric plate) is a massive, irregularly-shaped slab of solid rock, generally composed of both continental and oceanic lithosphere. In 1967, McKenzie and Parker suggested the theory of plate tectonics. It states that the Earth’s solid outer crust, the lithosphere, is separated into plates that move over the asthenosphere, the molten upper portion of the mantle.

Explanation: 1. The average density of oceanic crust is 3.0 g/cm3 , while continental crust has an average of 2.7 g/cm3 . The mass of the continental crust is 2.195. The continental crust (about 30 km) is composed of lighter (felsic) sodium potassium aluminum silicate rocks, like granite. The oceanic crust (about 5 km) is composed of dense (mafic) iron magnesium silicate igneous rocks, like basalt.

Explanation: 2.7 Percent. The present Antarctic ice sheet accounts for 90 percent of Earth’s total ice volume and 70 percent of its fresh water.

Explanation: An Earthquake. Over 80 percent of earthquakes occur around the edges of the Pacific Ocean, an area known as the ‘Ring of Fire’. Instrument used for measuring Earthquake: Seismograph.

Explanation: Nazca plate : Between South America and the Pacific plate. Seven major plates: African, Antarctic, Eurasian, Indo-Australian, North American, Pacific and South American.

Explanation: 35 o/oo (35 parts per thousand). Salinity is the amount of salt present in 1000 grams of water. A salinity of 24.7 % has been regarded as the upper limit to fix ‘brackish water’.

Explanation: Hurricanes. Tsunamis are giant waves caused by earthquakes or volcanic eruptions under the sea.

Explanation: Gulf stream. The Gulf Stream current in the North Atlantic and the Kuroshio Current in the North Pacific are warm currents. Warm Currents – Alaskan Current, Tsushima Current, Brazilian Current etc. Cold Current – Labrador Current, Canary Current, Benguela Current, Falkland Current, South Indian Ocean Current, Okhotsk Current, Humboldt or Peruvian Current etc.

Explanation: three. The movement of the plates creates three types of tectonic boundaries: convergent, where plates move into one another; divergent, where plates move apart; and transform, where plates move sideways in relation to each other.

Explanation: Carbon dioxide. Ocean acidification is the worldwide reduction in the pH of seawater as a consequence of the absorption of large amounts of carbon dioxide by the oceans. It results in the alteration of marine food chains and food supply to humans.

Explanation: Challenger Deep. It is located beneath the western Pacific Ocean. Factorian Deep is the new deepest point in Antarctica’s Southern Ocean. The Great Blue Hole is a giant marine sinkhole off the coast of Belize. The great barrier reef is the world’s largest coral reef located in Australia.

Explanation: water cools slower than land. The wind blowing from land towards the sea is the Land breeze. The wind blowing from the sea towards the land is a Sea breeze. Both are induced by differences that occur between the heating or cooling of the water surface and the adjacent land surface.

Explanation: Canada. The Polar region covers parts of eight countries: Canada, Greenland, Iceland, Norway, Sweden, Finland, Russia, and the United States.

Explanation: Infiltration occurs when surface water enters the soil. Depletion is an accrual accounting technique used to allocate the cost of extracting natural resources such as timber, minerals, and oil from the earth. Replenishment of the mineral resources includes the process of mineral deposit exploration.

Explanation: Arctic Ocean is the smallest and shallowest of the world’s five major oceans. The Arctic Ocean is centered approximately on the North Pole. The Pacific Ocean represents 45 percent of the global ocean coverage. The Indian Ocean occupies 20 percent of the global sea area. The Southern Ocean circles Antarctica and connects the Indian, Atlantic, and Pacific oceans.

Explanation: The Siberian shelf in the Arctic Ocean. A continental shelf is the edge of a continent that lies under the ocean. Example of a Continental Shelf Landform: Siberian Shelf, Arctic Ocean.

Explanation: Continental crust, the the outermost layer of Earth’s lithosphere is mostly composed of different types of granites. It is rich in Aluminium and silica.

Explanation: Atoll. Examples – Atoll Caroline Islands, the Coral Sea Islands, the Marshall Islands, the Tuamotu Islands, Kiribati, Tokelau, and Tuvalu. Guyot is an undersea mountain. Lagoons are shallow bodies of water that are separated from the ocean by a barrier reef. Seamounts are underwater mountains that rise above the ocean floor but do not reach the surface.

Explanation: Atlantic Ocean. Arabian Sea, Northwestern part of the Indian Ocean, lying between India and the Arabian Peninsula. The Red Sea contains some of the world’s hottest and saltiest seawater. It is red because it contains a cyanobacteria called Trichodesmium erythraeum.

Explanation: One cycle of tides actually takes 24 hours and 50 minutes. The highest tides occur when the Moon is new or full.

Explanation: Sargasso Sea. It is a part of the Atlantic Ocean. It is named so because of the presence of brown Sargassum seaweed.

Explanation: North America. The ancient supercontinent Gondwana incorporated present-day South America, Africa, Madagascar, India, Australia, and Antarctica.

Explanation: 1013.25 millibars. The air pressure decreases as the altitude increases.

Explanation: 4. The Bureau of Indian Standards has classified regions in India into 4 seismic zones on the basis of historical seismic activity. These are zones II, III, IV and V. Zone V is the most seismically active region and Zone II is the least active. The magnitude scale used to measure earthquakes ranges from 1 to 12.

Explanation: Tethys. This Sea separated the supercontinent of Laurasia in the north from Gondwana in the south.