PANAJI: In a major find through a project undertaken by the Goa-based National Institute of Oceanography ( NIO ), scientists have excavated the ancient submerged site of the Harappan port town of Dholavira which reveals to the world India’s maritime history.Located in Gujarat, Dholavira was the largest port-town of the Harappan civilization that flourished for about 1,500 years. Researchers have been perplexed about why the civilization came to an abrupt end. Archaeological excavations indicate that the township comprised of the castle, the middle town and the lower town.Dholavira is the oldest known site in the world which could have been hit by the tsunami, experts at the NIO said. As per their latest findings, there is indication of marine sediments possibly transported to the site by an extreme oceanic incident, which they attribute to the tsunami.A team of palaeo-climatologists, marine archaeologists and geophysicists from NIO surveyed an unexcavated area of the lower town using ground penetrating radar (GPR).What lay beneath the surface were remains of construction from the civilization that were buried under a layer of 2.5 to 3.5 meter thick homogenous soil.After systematically collecting the soil samples and examining the same, the scientists found fossils of foraminifera, that is, microscopic organisms that build calcareous shells and live only in seawater.The presence of these shells in the soil strongly suggests an episodic deposition of marine sediments in the area. “The deposition of such a component from seawater into the soil could have occurred due to forceful movement caused by an extreme oceanic event, like the tsunami,” said director, NIO, Dr S W A Naqvi.One of the most intriguing features of Dholavira is the presence of a 14-18 meters thick wall at the site.Sharing his thoughts about the same, chief scientist, Dr Rajiv Nigam who led the research said, “Most Harappan walls have fortification but nowhere have any walls been constructed with such thickness. This indicates that ancient Indians were aware of protection measures against the tsunami or storms surges. Harappans were thus pioneers in coastal disaster management. Most importantly, results of this study opens the possibility that Dholavira, at least in part, could have been destroyed by such a tsunami,”This begs the question as to why the people of Dholavira would choose to build a civilization around such a vulnerable area. “Dholavira was an economically strategic location. So they built the city despite being prone to storms and protected it with a thick wall,” added Nigam.Dholavira was well connected to the ocean 5,000 years ago but it’s not anymore owing to shifts due to tectonic movement.Further research will enable NIO to date the calcareous shells and determine when the tsunami may have taken place.“We would like to pursue this project and are currently awaiting funds from the central government,” said Nigam.For more research, close grid survey of the site is required for which NIO has applied to the Union ministry of art and culture. The budget for the same is Rs 35 lakhs. NIO doesn’t have a mandate for excavation as the authority for the same is only under the archaeological survey of India (ASI). They are optimistic that the ASI will go ahead with the excavation.