Mahaadweep aur mahaasaagar: duniya ka chhota sa tour

Saat mahaadweep, paanch mahaasaagar

Mahaadweep zameen ka ek bada, lagaataar faila hissa hai. Aam ginti mein saat hain: Asia, Africa, North America, South America, Antarctica, Europe aur Australia. Inke chaaron taraf paanch jude hue mahaasaagar hain: Pacific, Atlantic, Indian, Southern aur Arctic. Pacific sabse bada aur sabse gehra hai, jismein whales aur tuna hain; Atlantic jahazon ke sabse vyast raaston mein se ek aur machhli ka bhandaar hai; Hind Mahaasaagar garam hai, jeevan se bhara hai aur hazaaron saal se vyapaar le jaata raha hai; Southern Ocean Antarctica ko gherta hai, jahan penguins aur seals hain; aur Arctic, sabse chhota aur uthla, samudri barf se dhaka hai aur polar bears aur walruses ka ghar hai.

Mahaasaagar kyon zaroori hain

Khaara paani Prithvi ki satah ka lagbhag 71% dhakta hai, isliye astronauts ne ise blue planet kaha, aur mahaasaagaron mein Prithvi ka lagbhag 97% paani hai. Nanhe plankton, jo dhoop aur carbon dioxide se khaana banaate hain, hamari saans ki lagbhag aadhi oxygen dete hain. Mahaasaagar climate ko bhi sambhaalte hain: garmi sokhte hain, use dheere chhodte hain aur hawa mein nami jodte hain, jo baadal aur baarish banti hai. Inka jeevan plankton se blue whale tak hai, jo sabse bada mammal hai aur 30 m se lamba hota hai. Samudra tal bhi samtal nahi hai; usmein zameen ki tarah pahaad, ghaatiyaan aur maidaan hain.

Currents, trenches aur reefs

Samudra ka paani hamesha chalta rehta hai. Currents badi nadiyon ki tarah behti hain: garam currents Equator se dhruvon ki taraf paani le jaati hain, aur thandi currents dhruvon se Equator ki taraf. Garam Gulf Stream Atlantic paar karke Western Europe pahunchti hai aur United Kingdom jaisi jagahon ko apne jaise latitude ki doosri jagahon se naram rakhti hai. Samudra tal ke sabse gehre hisse V-aakaar ki trenches hain. Mariana Trench mein Challenger Deep 11,000 m se zyada neeche jaata hai, jahan thanda, andhera aur kuchalne wala dabaav hai, aur jeev chemicals se khaana banaate hain. Reefs, yaani satah ke paas ki patti jo aksar corals banaate hain, Prithvi ke sabse samriddh ecosystems mein hain. Australia ke paas Great Barrier Reef 2,000 km se lamba hai.

Seas, gulfs, bays, straits aur canals

Geographers chhote jal-kshetron ke naam unke aakaar se rakhte hain. Sea, jaise Arabian Sea, kuch had tak zameen se ghira hai par mahaasaagar se juda hai. Gulf, jaise Persian Gulf, zameen mein gehraai tak jaata hai, jabki bay, jaise duniya ki sabse badi bay, Bay of Bengal, chhoti aur chaudi hoti hai. Strait, jaise Strait of Malacca, do samudron ya mahaasaagaron ko jodne wali sankari patti hai, aur canal insaan khodte hain: 1869 mein khuli Suez Canal Red Sea ko Mediterranean se jodti hai.

Har mahaadweep ke landforms

Zameen par mukhya landforms pahaad, plateau aur maidaan hain, aur registaan bhi, jahan saal mein 25 cm se kam baarish hoti hai aur jo garam ya thande ho sakte hain. Har mahaadweep ki apni mashhoor misaalein hain: Asia mein Tibetan Plateau aur Gobi Desert, Europe mein European Plain aur Alps, Africa mein Sahara aur Nile, South America mein Andes aur Amazon, North America mein Rocky Mountains aur Great Lakes, aur Great Australian Desert. Sabse bada registaan barfeela Antarctica hai. Poora tour Chapter 1 ke notes mein hai; maps ke liye Prithvi ka map banaana padho, aur har sawaal ka jawab NCERT solutions mein hai.