महासागर

prithvi ke lagabhag 71 pratishat bhag par sagar phaile hue haian. vishv ke mahasagaroan evan sagaroan ka kshetraphal 367 miliyan varg kilomitar hai, jo mangal grah ke kshetraphal ka do guna tatha chaand ke kshetraphal ka nau guna hai. vishv ka lagabhag 98 pratishat jal sagaroan mean, lagabhag 2 pratishat nadiyoan, jhiloan, bhoogart tatha mitti mean hai. jal ki bahutayat ke karan prithvi ko 'jal grah' (Water Planet) kaha jata hai. yadi prithvi ke uchchavach ko sagar mean dalakar samatal kar diya jae to poori prithvi par sagar ki gaharaee lagabhag 2.25 kilomitar hogi. jal ke karan hi prithvi par jivan sambhav ho saka. prithvi ke 70.8 pratishat par mahasagar evan sagar phaile hue haian. vishv ke paanch mahasagar haian, jinake nam-

1. prashaant mahasagar (Pacific Ocean)
2. aandh mahasagar (Atlantic Ocean)
3. hiand mahasagar (Indian Ocean)
4. arkitak mahasagar (Arctic Ocean)
5. aantarkitak athava dakshini mahasagar (Antarctic or Southern Ocean)

mahasagaroan ke adhikatar tal bad mean bane hue haian, jinaki ayu ath karo d varsh se kam hai. yooreshiya tatha aphriki pletoan ke ek doosare ke nikat ane tatha takarane (Collision) se aj ke mahadvipoan tatha mahasagaroan ka svaroop bana.

panne ki pragati avastha

adhar

prarambhik

madhyamik

poornata

shodh