Mawmluh Cave: The Key to the Past and the Future

Said to be the fourth longest cave in the Indian subcontinent, 7 km long Mawmluh cave in Meghalaya has evoked considerable interest among world geologists.

UNESCO’s International Union of Geological Sciences (IUGS) recently listed the cave as one of the ‘First 100 IUGS Geological Sites’ in the world. The formal announcement is to be made at the IUGS 60th anniversary celebration in Spain 25-28 October 2022, Meghalaya chief minister Conrad Sangma shared on Twitter.

The cave, with its entrance located at a height of 10 feet above the sea level, boasts of calcite formations of various kinds, massive caverns and columns of stalagmite, waist-deep pools, “a few metres of belly crawl and a few climbs”. Only a fourth of the cave is said to receive sunlight. People with respiratory problems and those who suffer from claustrophobia are advised against visiting the cave. There is also a pool inside the cave formed, it is believed, by five different rivers finding their way inside the cave.

Geologists from across the country and several from abroad have evinced great interest in the cave, where columns of calcium, limestone and other minerals deposited by monsoon water dripping from the roof have formed stalagmites and calcites. The layers of mineral deposited over thousands of years, geologists say, are helping them understand climatic changes, especially the pattern of the monsoon, in the past. They also believe it is possible to forecast possible changes in the future. It will be possible to predict weather patterns, droughts and floods with greater accuracy.

A research paper published in the September 19 issue of the ‘Proceedings of the National Academy of Sciences’ has confirmed that mineral deposits caused by centuries of water seepage in the cave close to Cherrapunji, 53 km from Shillong, are helping scientists unravel weather patterns. In 2019 a research team from Vanderbilt University in the US had also claimed, after a visit to the cave, that it held the key to several mysteries related to climate change.

The mineral deposits, researchers believe, have formed over a thousand years or more because of rainwater dripping from the roof. Over centuries, the sediments gave rise to columns of calcium carbonate. The layers of the minerals hide the history of rainfall patterns in the past, they have concluded. By extrapolating the data, they can now even predict large-scale climate changes.

The scientific paper in the research journal claims that severe and prolonged periods of drought had occurred between 1595 AD and 1620 AD in several parts of India. It goes on to speculate that this could have been one of the reasons for the Mughals to shift their capital from Fatehpur Sikri.

An optimistic Dr. Tilak Thakuria of North Eastern Hill University, Meghalaya, hopes the studies will prove valuable in dealing with severe weather changes in the future.

Scientific and systematic measurement of rainfall during monsoon began only in 1870. The paper records that since then 27 spells of severe drought have been recorded in the country including the drought over three consecutive years between 1985 to 1987. While the data do not help looking into the past, the deposits inside the Mawmluh cave, the scientists hope, will help unravel several of the mysteries.