Using advanced US laser technology, ISRO unravels Ram Setu secrets

In a pathbreaking discovery, the Indian Space Research Organisation (ISRO) has successfully mapped the submerged construction of Adam's Bridge, also called Ram Setu.

Now, the entire length of the underwater bridge can be seen in through a 10-meter resolution map created by the researchers using ICESat-2 data collected between October 2018 and October 2023 ― sufficient to catch features akin to the size of a train coach.

The bridge continues from Dhanushkodi in India to Talaimannar in Sri Lanka, as shown by the comprehensive underwater map, with an astounding 99.98% of its length submerged in shallow seas.

The ancient Adam's Bridge connects India and Sri Lanka, and is recorded in Indian religious writings as Ram Setu.

According to a report published in the Scientific Reports journal, a high-resolution map of the submerged bridge was made by ISRO scientists using advanced laser technology from a US satellite.

Under the direction of Giribabu Dandabathula, a scientist at ISRO, the research team discovered 11 narrow passages that allow water to pass between the Palk Strait and the Gulf of Mannar, and are essential for protecting the structure from the waves of the sea.

The research confirms the origins of Adam's Bridge, which was formerly a land bridge linking Sri Lanka and India. The findings offer fresh perspectives on the history of the area and the construction of the centuries-old structure.

A cartographer for the East India Company named is believed to have named it Adam's Bridge. The structure is recorded in the Ramayana as a bridge built by Lord Rama's army to help him reach Sri Lanka, Ravana's kingdom, to rescue his wife Sita.

In the ninth century AD, Persian navigators referred to the bridge as Sethu Bandhai, meaning "bridge over the sea." According to temple records from Rameswaram, the bridge stood above sea level until 1480, when it was wrecked by a violent storm.

Earlier, satellite observations indicated the presence of an underwater structure. However, the exposed portions of the bridge were the main subject of these observations. The area's sea is incredibly shallow, with sections only one to ten meters deep, making it challenging for ships to navigate and explore the ridge.