ISRO reveals detailed undersea mapping of ancient Ram Setu
Covering a 29-kilometer stretch of limestone shoals submerged in shallow waters between Dhanushkodi in India and Talaimannar in Sri Lanka, the survey marks the most precise mapping of this ancient structure to date.
News Arena Network - Bengaluru - UPDATED: July 9, 2024, 06:26 PM - 2 min read
(Image on left) Location map of Adam’s Bridge. (a) The map shows India and Sri Lanka by highlighting the extent of Adam’s Bridge with a yellow box. (b) The map shows Rameshwaram Island (Indian side) and Mannar Island (Sri Lankan side) and highlights Adam’s Bridge with a white box that constitutes the study area. (c) Satellite Image showing Adam’s Bridge, which stretches from Dhanushkodi to Talaimannar. (Image on right) (a) Perspective view of Adam’s Bridge from the Gulf of Mannar as an observer position. (b) Perspective view of Adam’s Bridge from Palk Strait as an observer position.
In a remarkable breakthrough, scientists from the Indian Space Research Organisation (Isro) have meticulously mapped Adam’s Bridge, popularly known as Ram Setu, using advanced laser technology.
Covering a 29-kilometer stretch of limestone shoals submerged in shallow waters between Dhanushkodi in India and Talaimannar in Sri Lanka, the survey marks the most precise mapping of this ancient structure to date.
The mapping exercise, conducted with data from a US satellite reflecting laser beams off the sea floor, confirmed that 99.98 percent of Ram Setu remains submerged.
This initiative was led by Giribabu Dandabathula and his team from Isro’s National Remote Sensing Centre in Jodhpur regional center, detailed in the journal Scientific Reports.
Originally named Adam’s Bridge by a British East India Company mapper, the structure holds significant cultural and historical importance in Indian mythology, known as Ram Setu from the epic Ramayana.
According to legend, it was built by Lord Ram's army to reach Sri Lanka, the kingdom of Ravana, and rescue Goddess Sita.
Geological evidence supports the belief that this submerged ridge once served as a land bridge between India and Sri Lanka.
Records from Persian navigators in the ninth century AD referred to it as Sethu Bandhai, highlighting its strategic importance in maritime history.
Isro’s detailed mapping using ICESat-2 data from 2018 to 2023 revealed that the ridge averages around 8 meters above the sea bed, with only a fraction visible above water.
The structure, primarily composed of limestone formed from marine fossils over millions of years, includes 11 narrow passages facilitating water exchange between the Gulf of Mannar and Palk Strait.
(Left) Depiction of the narrow channels along Adam’s Bridge’s crest line. (a) Satellite image showing the exposed sand banks along the Adam’s Bridge crest line. (b) The Elevation profile along Adam’s Bridge’s crest line shows narrow channels up to a depth of 3 m. (c) The three-dimensional perspective of Adam’s Bridge shows the narrow channels enabling water exchange between the Gulf of Mannar and the Palk Strait. (Right) New ICESat-2 data reveals detailed bathymetric features of Adam’s Bridge, highlighting its submerged limestone structure and narrow water passages."n
These passages, crucial for managing wave impact during monsoons, underscore the bridge’s resilience against the forces of nature.
They facilitate the flow of water between the Arabian Sea and the Bay of Bengal, contributing to the conservation of this ancient marvel.
The evolution of Adam’s Bridge dates back millions of years when India and Sri Lanka were part of the ancient supercontinent Gondwanaland.
Subsequent geological shifts and sea level changes shaped the land bridge, which has alternately been exposed and submerged over epochs of time.
Isro’s findings not only provide unprecedented insights into the structure’s geological formation but also reaffirm its cultural significance in Indian heritage.
This meticulous mapping sets a new benchmark in underwater archaeological studies, shedding light on a relic of antiquity that continues to intrigue and inspire.
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