India has a coastline of 7516.6 km (Mainland: 5422.6 km; Island Territories: 2094 km). The straight and regular coastline of India is the result of faulting of the Gondwanaland during the Cretaceous period. The origin of Western and Eastern Coasts of India may be attributed to faulting and subsidence of the Arabian Sea and Bay of Bengal blocks towards the end of the Ecocene period.
Eastern Coast of India
It extends from the Ganga delta to Kanyakumari.
1. This coast is emergent type which is characterised by offshore bars, sea beaches and lagoons.
2. It is aggradational plain (It is the term used in geology for the increase in land elevation, typically in a river system, due to the deposition of sediment) formed by the rivers sediments.
3. Get maximum cyclonic storms and fit for predominantly rice and jute cultivation.
4. It is sandy with alluvium and slopes gently towards the sea. Sand dunes and marshy lands are also found. In some Coastal strips lagoons (Chilka, Pulicat) are formed.
5. It has straight shorelines and consists mainly of recent and tertiary alluvium deposits.
6. It is washed by the Bay of Bengal.
7. It receives comparatively low rainfall.
8. It receives rains from North East Monsoons.
9. Regional names of Eastern Coast: Odisha= Utkal Coast; Tamil Nadu= Coromandal Coast or Payan Ghat.
Western Coast of India
The west coast extends from the Gulf of Cambay in the north to Cape Comorin.
1. It is fault coast and shows marks of subsidence except in Malabar coast in south where evidence of emergence is found.
2. It is narrow plain drained by many swift but small rivers.
3. Estuaries are predominantly instead of deltas as in Eastern coast.
4. It is relatively rocky with sand and sand dunes. It slopes abruptly down to the sea. There is no lagoon on the northern part. It has many estuaries on the Konkon Coast. But the southern part especially the Malabar Coast has the beautiful scene of back-water country with a series of lagoons. Back waters locally called Kayals are found in Malabar Coast, e.g. Vembanad Lake.
5. Western continental margin is much broader than the Eastern counterpart.
6. It is washed by the Arabian Sea.
7. It receives heavy rainfall.
8. It receives rains from South West Monsoons.
9. Regional names of the western coast: Konkan coast = Maharashtra coast and Goa coast; Malabar Coast = Kerala and Karnataka coast.