List the reasons for variations in salinity in the various oceans.

The following factors are the reasons for salinity variation in the ocean,

1. Most common factor which affects or varies the salinity is the rock erosion or rock weathering in the ocean. It pours the salt as well as the minerals into the oceanic water.

2. Other factor is the rate of evaporation which differs as per the oceanic surroundings.

3. Then, ice formation in the sea that increases the salinity in the ocean.

4. Other cumulative factors decreases ocean's salinity. It includes the drainage of river or fresh water in the ocean, with the altered rate of precipitation and meltdown of ice.

answer (a) more rain in u s and less rain in australia and asia