- Varkala cliffs offer snapshots of geological time covering millions of years.
- They sustain unique biodiversity, freshwater sources and fishing livelihoods.
- They are under threat from heavy rains, swells from distant storms and building activities.
With its honeycake-coloured layers of off-white, yellow, ochre, red and brown, the cliffs of Varkala in northern Thiruvananthapuram attract tourists from across the world starting November. This year, local conservationists are on a mission to save these ancient rock formations exposed to recent torrential rains, high waves, coastal erosion, and damage from infrastructure development measures.
Stretching 7.5 km on the backshore, the golden-sand beach between the high-water mark and the landward limit of wave action, these cliffs are a rare geodiversity spot. Their minerals, rocks, fossils, soils, sediments, and landforms, as well as land and water features merit conservation, going by the global norms.
They offer a timeline to study the earth’s evolution and offer a lifeline to the local communities with its biodiversity and freshwater resources.
Rampant destruction
Conservationists of Kerala, God’s Own Country, as the state tourism department advertises it, say the cliffs face challenges as the area gets crowded. A certain lack of awareness about their significance is probably the hardest to mount, they say.
Over the years, there has been hectic construction on the cliff – restaurants, resorts, parking lots and a helipad. The defining moment came in early June when the district administration of Thiruvananthapuram sent bulldozers to demolish a part of the cliffs to prevent landslides. The background is that landslides are threatening the highlands and hillslopes of Kerala as the changing climate brings more intense rains of late. The demolition happened near a spot where people perform last rites for their dear and near.
“The demolition of the cliff was shocking,” said Geological Survey of India Deputy Director General (Kerala Unit) V. Ambili while talking to the media. “The cliff is a prestigious site with immense geological and geomorphological relevance,” she said.
Geological Survey of India intervenes
Visiting Varkala, India’s Minister of State for Tourism Suresh Gopi, a former film star from Kerala, said that urgent measures would be taken to protect the cliffs.
Meanwhile, Geological Survey of India (GSI) noted that the cliffs have been declared a “national geo-heritage site” in 2014. The World Heritage Convention protects extraordinary places characterised by their beauty, biodiversity, ecosystem, and geological values. GSI also suggested a set of conservation measures ranging from slope and foot protection, greening, and a ban on further construction on the cliff.
“Unscientific construction of buildings, resorts, slope modification done for construction activities along the top of the cliff and both sides of the cliff are observed to be one of the causative factors of slope instability,” GSI noted.
The measures suggested by GSI include laying biodegradable jute mesh on the slope and planting deep-rooted stunted plants and shrubs. “In a year, the shrubs will grow and deep roots will hold the subsurface water and arrest the chances of the slide,” GSI noted in a recent reply to a Right to Information (RTI) query filed by Thomas Lawrence, who leads the conservation group Save Wetlands International Movement.
Geological heritage
Cliffs are massive rocks that rise high, almost vertically, cut, chiselled, and sandpapered by waves and weathered by wind and rain. On sea cliffs like the ones in Varkala, the waves wash away the sediment left by weathering and make it part of the seabed.
According to the GSI, the Varkala cliffs are at least 5.3 million years old. “It exposes the entire Mio-Pliocene sequence of Warkalli Formation,” noted a 2022 paper in the International Journal of Geoheritage and Parks. In the geologic timeframe, the Miocene extends from about 23 to 5.3 million years ago, followed by the Pliocene, which extends from 5.3 to 2.6 million years ago.
“The nearly straight west coast of India (a consequence of the West Coast Fault – WCF), as noticed in Varkala, is a manifestation of several episodes of tectonic activity. The Indian Peninsula, once part of the Gondwana Supercontinent, on breakup, detached from the Mascarene plateau during… the last episode of Gondwana split-up,” the above paper noted.
A fault is a fracture or zone of fractures between two blocks of rock, and they allow land masses to move against or along one another. Gondwana was the ancient supercontinent that included today’s South America, Africa, Arabia, Madagascar, India, Australia, and Antarctica, and started breaking up some 180 million years ago. By 23 million years ago, Gondwana no longer existed, but it left a common heritage of fauna, flora and landforms.
The Mascarene Plateau is a submarine formation in the Indian Ocean, north and east of Madagascar. “The WCF, between Panvel (Maharashtra) and Kanyakumari (Tamil Nadu), also reflecting the straight aspect of the west coast, was supposedly the zone of detachment,” noted the 2022 paper led by K. S. Sajinkumar, a faculty of Kerala University and Michigan Technological University.
The Red Planet nexus
Apart from its Gondwana connection, the cliffs of Varkala are also home to some rare minerals that aid scientists engaged in planetary studies. The cliff exposes formations of sandstones and grit of plastic clays and sandy clays enclosing thin seams of lignite with a top layer of hard laterite. “They are excellent analogues for Martian studies, as they contain a mineral called Jarosite,” Sajinkumar told Mongabay India. Jarosites are a major component of acidic soils, and they come as industrial byproducts.
“Jarosite is formed through the interaction of pyrite or marcasite – both iron sulphide minerals formed in anaerobic (no-oxygen) conditions – and is exposed to the atmosphere and saline water,” Sajinkumar, said. “This means that a conducive atmosphere and saline water source was available on Mars too.” Jarosites were the first hydrated minerals found on Mars, a key to unlock the environmental history of water on the Red Planet.
Fishers’ support system
In its crevices, fissures, ledges, and terraces, cliffs host plants that are not found in nearby forests, scrublands, or grasslands. These “microhabitats” with optimal humidity and temperature hold just enough soil for the microbes that help plant growth. “Laterite cliffs are excellent habitats for certain herbs,” said A. Bijukumar, professor and head of the Department of Aquatic Biology and Fisheries at the University of Kerala. “We have studied them in Kannur (in northern Kerala), but not here,” he told Mongabay India.
Besides, there are underwater reefs close to the Varkala cliffs that are rich fish habitats. There are also exposed laterite rock formations – that are connected to the cliffs – on the shores of nearby villages and elsewhere along the west coast. Fishermen often dive and chisel off mussels attached to these rocks. There are local fishing communities that specialise in this work.
“The wave action brings a lot of shellfish to the shore as well, and we could see a rich collection during our field visits to Varkala,” said Robert Panipilla, who leads the conservation group Friends of Marine Life (FML) based in Thiruvananthapuram.
“However, the greatest ecosystem service offered by the cliff is water harvesting for the coast,” Bijukumar said. “Places close to these cliffs have the finest water.” While the sandstone and grit act as aquifers, the hard laterite layer on top caps them, and the water spouts as free-falling springs, as research shows.
Scientists for conservation
Scientists are concerned that more human activity will hasten the erosion of the cliffs, a slow, inevitable, natural process. “Building activities destroy the top laterite layer of the cliffs, exposing its softer sandstone beneath to weathering,” Raghunathan Pillai, a former director of GSI, told Mongabay India.
“During the monsoon, the wave activity is very high, and it makes the cliffs more vulnerable,” he added. As such high wave and swell events are becoming more frequent due to climate change. Swells come from storms in distant oceans, ocean scientists have pointed out.
The Kerala government and GSI plan to preserve and protect the cliffs under the law. “But unfortunately, it is at a snail’s pace. GSI should take it up on a war footing,” Sajinkumar said. Meanwhile, Bijukumar and colleagues are planning to study the biodiversity of the cliffs and the reefs nearby.
Banner image: Varkala cliffs face rapid development, with restaurants, resorts, parking lots, and a helipad reshaping the landscape. Image by K. S. Sajinkumar
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