Did you know that that about 18,000 years ago, the sea was 50 km away from the spot you are standing today? The question posed by D. Rajasekhar Reddy, INTACH’s adviser for geo-heritage and convener of its Visakhapatnam Chapter, left the participants of a ‘geo-heritage walk’ organised on Thursday at the Mangamaripeta beach surprised.
The walk organised by the INTACH’s Vizag Chapter and Eastern Naval Command (ENC) marked the UNESCO’s International Geo-Heritage Day, which is observed on October 6 every year.
Professor Rajasekhar explained the participants that every site, including the beaches, have geo-heritage values and they need to be protected.
“Blessed with ample geo-diversity, the beaches in Visakhapatnam are unique. The 25-km coastal stretch from Visakhapatnam to Bheemunipatnam exhibits a lot of diversity in material content, beach geomorphic features and straightness of the coastline, which are the outcome of centuries of natural process and response system,” said prof. Rajasekhar.
He pointed out that towards north of Bheemunipatnam, the Gosthani River joins the Bay of Bengal. It is estuarine beach system and the corresponding features include well-developed sand dunes. Further south, towards the central part, it is a rocky beach while towards the southern end towards the Ramakrishna beach, the coastline is sandy.
Showcasing various features at the Mangamaripeta beach, he explained how sea water over the years had contributed in the formation of features such as natural bridge, stacks, sea caves, serpentine hoods, sheath structures and wave-cut platforms.
“All these features are the result of continuous hydrodynamic actions of sea waves, tides and currents on the rocks and the nature and orientation of their weaker planes such as the foliation planes, joints, fractures and mineral susceptibilities,” explained prof. Rajasekhar.
The hydrodynamic forces continue to exert pressure on the rocks and keep modifying them, he said.
About 150 members from the ENC and their families and INTACH members took part in the geo-heritage walk.
