Ocean Circulation

1. Waves 

 

✅Example : Tsunami→ Japanese word Harbour Waves 

✅ First indication that tsunami is approaching is the rapid withdrawal of water from coastal region, followed by destructive wave. 

  

✅ Due to earthquake => Indian plate moved under Burma Plate. 

✅Some common methods to predict earthquake adopted locally by people→ studying animal behaviour, fish in ponds get agitated, snakes come to surface.

 

2. Tides 

 

✅Rhythmic rise and fall of ocean water twice in a day is called tide. 

✅High Tide→ when water covers much of the shore by rising to its highest level. 

✅ Low Tide→ When water falls to its lowest level and recedes from the shore. 

✅Cause→ The strong gravitational pull exerted by the sun and the moon on the  

earth’s surface causes the tides.

✅The water of earth closer to the moon gets pulled under the influence of moon’s gravitational force and causes high tide.

 

🔸Types

 

1. Neap Tide 

2. Spring Tide 

✅Spring Tides: During full moon and new moon days. The sun, the moon and earth are in the same line and tides are highest. These tides are called spring tides. 

 

✅Neap Tides: When moon is in its first and last quarter, the ocean waters get drawn in diagonally opposite directions by gravitational pull of sun and  

earth resulting in Low Tides. 

✅These tides are called Neap Tides.

#geography 

#prelims 

#mains