Aathira Perinchery 
Bengaluru: On Friday (August 9) morning, residents in and around Wayanad’s Nenmeni and Ambalavayal villages reported hearing a loud, thunderclap-like sound echoing from underground, near a mountain. Houses shook, windows and doors rattled, and many residents ran out of their homes. And they had much reason to worry — their villages are just within a 10-13 km-radius from where the multiple landslides on July 30 occurred, claiming more than 220 lives as per official estimates. More than 100 people are still missing.
Residents in villages and towns across the neighbouring districts of Malappuram, Kozhikode and Palakkad also reported hearing the noise and feeling vibrations. Seismologists and geologists, however, say that though caution is necessary, there is not too much to worry about. These are possibly natural phenomena caused by the shifting of rock masses in the aftermath of the Wayanad landslides, they added.
Wayanad, meanwhile, is set to welcome Prime Minister Narendra Modi tomorrow (August 10). Modi is scheduled to visit relief camps in the area. The rescue personnel are still unearthing dead bodies. On August 9, the 11th day of rescue operations, personnel unearthed four more dead bodies from Soochipara near Meppadi, , one of the affected sites.
Like a very loud “thunderclap” and “gunshot”
On the morning of August 9, at around 10.15 a.m., residents in and around the villages and towns of Nenmeni, Ambalavayal and several other places in Wayanad district heard a loud, echoing sound emanating from the ground. Some described it as a very loud thunderclap, booming from underground; one person compared it to a loud gunshot.
Vessels clattered, windows and doors rattled, and houses shook. Many residents ran out of their homes. A middle-aged man told local news channels that the jeep he was driving at the time shook and he had to stop the vehicle.
According to local television channels, areas that experienced the phenomenon included Mundakkai and Chooralmala which have borne the brunt of the recent landslides, as well as Vythiri, Kurichiarmala and Sugandhagiri. Residents living below the Edakkal caves near Nenmeni also confirmed hearing the sound and feeling the vibrations.
Panchayat authorities immediately closed local schools and anganwadis. They stopped workers engaged in work under the MGNREGA scheme, and asked them to go home. Within a few hours, authorities had even set up a potential relief camp in the Ambalavayal government school in case things got worse.
No losses or damages have been reported so far. Several areas in some neighbouring districts too experienced the vibrations or “prakambanam”, including Edappal in Malappuram, Kuttiyady in Kozhikode district and Ottapalam and Lakkidi in northern Palakkad.
Possibly caused by shifting of underground rock masses
K. Rajan, state revenue minister, told local television channels that it was not an earthquake because none of the government’s seismographs in the state, including the Kerala State Electricity Board, registered any readings.
I.C. Balakrishnan, MLA from Wayanad said that after discussions with the district collector and officials of the disaster management authority, they had come to the conclusion that it was not an earthquake as locals suspected.
The head of the State Disaster Management Authority has also asked people not to worry, Balakrishnan told the media. He said that authorities would undertake a field study to ascertain the cause of the sound and vibrations.
The phenomenon in Wayanad is likely to be a shifting of land, a “completely natural phenomenon”, O. P. Mishra, director of the National Center for Seismology in New Delhi told Mathrubhumi News. He told the local news channel that none of the government’s seismographs in stations in or around Kerala registered vibrations: they would have, if it had been an earthquake. It is likely to be a “localised event”, a shifting of rock masses from the upper to the lower level underground. When rock masses move this way, they can hit against each other and the resulting frictional energy can cause a soundwave, Mishra said. It is probably an aftereffect of the Wayanad landslides, he added.
S. Sreekumar, retired professor and geologist who has studied landslides in Kerala in detail, concurred. He told The Wire that this is normal to hear such sounds and echoes from under the ground during the rains in the state.
“These processes are usually associated with the movement of water through various levels of rock underground,” he told The Wire.
So when water passes through the cracks and fissures in rocks in these areas it can cause what is known as hydraulic fracturing, he said, adding that this can cause a loud noise.
Can such movement of water and the shifting of rock masses cause land subsidence — or the sinking of land — in some areas? Such phenomena can sometimes lead to land subsidence too but not always – there’s no way to know, Sreekumar said.
“We do have to be careful and alert, but at the same time there is no need for undue panic.”
Arrangements on for PM’s visit
Meanwhile, arrangements for Prime Minister Modi’s visit to Wayanad on August 10 are ongoing. Modi is scheduled to land at Kannur airport and reach the town of Kalpetta via helicopter, from where Meppadi is around 11 km by road.
The prime minister is scheduled to pay a visit to the Meppadi and Chooralmala relief camps, per local news channels.
The state and its people are on tenterhooks, wondering whether the Union government will finally declare the Wayanad landslides as a national disaster after Modi’s visit — the declaration will come as a relief for the state as it will enable the availability of additional funds for survivors’ rehabilitation and more.
Several Members of Parliament from Kerala and other states including Rahul Gandhi, who won the recent Lok Sabha elections from Wayanad and also visited the relief camps in the area after the tragedy, have requested the Union government to declare the landslides as a national disaster.
While official estimates provided by the state peg the death toll caused by the landslides at 226, the count is likely to be higher, as more than 100 people are still unaccounted for.
The Kerala high court on August 9, meanwhile, called for an “environment audit” in Wayanad district after the landslides.