The earthquake of 5.1 magnitude on the Richter scale that hit the Bay of Bengal around 12:35 p.m., about 296 km south-southeast of Kakinada, was due to differential compaction, as per an expert in earth sciences.
Explaining it in simple words, Prof. K.S. Krishna from the University of Hyderabad, who had earlier written a research paper along with M. Ismaiel titled ‘presence of fracture line in off-shore of Krishna-Godavari basin’ said, “There are a number of fracture lines or fault lines under Bay of Bengal and the accumulation of sediment from various river systems might trigger a slip in the fault line, which can lead to an earthquake, further resulting into a Tsunami, depending on the intensity of the earthquake.”
According to Prof. Krishna, apart from the presence of a 300-km-long fracture line in the offshore region of north A.P., about 100 km away from the coastline off Visakhapatnam, there are a number of fault lines in the deep water region in the Bay of Bengal and all of them can experience differential compaction. The one that happened on Tuesday off the coast of Kakinada, can be attributed to this.
A number of mighty rivers such as Krishna, Godavari and Brahmaputra flow into the Bay of Bengal carrying a huge amount of sediment, which increases the load on the fault lines and may result into underwater earthquakes.
Continental shift
In the last 200 million years, two super-continents,Gondwana and Laurasia, broke into a number of continental blocks and wandered to the present position. The edges of the continents are either active or passive.
The eastern margin of India broke apart from the East Antarctica 130 million years ago and the continental collision that occurred between India and Asia around 40 million years ago led to the formation of the highest mountain range in the world, the Himalayas.
“This was responsible for major changes in regional and global climatic conditions. Interactions between the Himalayan mountain range and Asian climate initiated erosional process in the Himalayan and Tibetan regions, thereby the river systems of the sub-continent carried copious amount of terrigenous material to the Bay of Bengal with a thickness reaching up to 22 km in Bengal offshore basin,” he explained.
