Lucknow, Nov 12 (IANS): Three earthquake tremors within a month was something the residents of Lucknow were not prepared for.
The tremors that shook Lucknow and other parts of the state last week – third time in a row – indicate that the Himalayan region has become the zone of frequent release of seismic energy and that the possibility of more of such earthquakes soon cannot be ruled out, said experts.
The earthquake was followed by bouts of nine minor aftershocks till next morning. Seismologists say that the rapidity of the tremors calls for residents and authorities to remain vigilant and alert.
The reason for frequent earthquakes, according to experts, is that the Indian (tectonic) plate is constantly moving towards the North at the rate of about 6.5 cm every year and it is colliding with the south-moving Tibetan plates. This is leading to frequent earthquakes and the corresponding aftershocks.
“The Indian plates are constantly moving ahead towards the North and coming in conflict with the South-moving Tibetan belt. Due to the collision, there is a release of energy,” said Lucknow University Prof Dhruv Sen Singh, a glacier expert.
“While there is no need to panic for the people in the Indo-Gangetic belt, of which Lucknow is a part, we do need to be alert and prepared for more such tremors as the plates try to adjust themselves,” he added.
The Himalayan region is known to be seismically one of the most active continental regions. Moreover, over half a dozen earthquakes that have occurred since January this year indicate a pattern.
“The entire Nepal region falls in the central seismic gap. The Doti region where the earthquake occurred last week has become a narrow zone of frequent release of seismic energy. And this energy can possibly be released in the form of earthquakes in the range of 7 to 8 magnitude. It cannot be predicted but it cannot be ruled out either,” said Dehradun-based seismologist Ajay Paul.
The region around the Indo-Gangetic plains, including Lucknow, has been immune to the shocks of the earthquakes. The presence of the loose alluvial soil in the region acts as a shock absorber. The region, however, is not immune to the tremors and their aftermath.
“Since the history of humanity, the region has not seen any earthquake. It has felt tremors but they have not resulted in any catastrophe or massive disaster. Having said that, the recent experiences do call for alertness, adherence to the structural designs that can withstand tremors, and increased awareness among the residents on pre and post-tremors behaviour,” Prof Singh said.
Besides, experts further argued that one cannot expect the nature of the soil to be unchanging. And despite the alluvial soil acting as a shock absorber, danger could be lurking around the corner due to our ignorance.
“Indo-Gangetic plain can absorb shocks but is not earthquake-resistant. Soft alluvial soil can also amplify tremors. Moreover, it can suffer the threat of liquefaction, where the entire soil layer starts moving when the tremor sets in. This impacts the foundation of the building,” said a geophysicist B. K. Maheshwari.
Experts have called for increased mock drills and the creation of a district-wise task force that could respond effectively during instances of strong tremors in the region. Besides, strict adherence to earthquake-resistant design for construction can avert any untoward incident.
Loss of life and property during earthquakes occur mainly due to collapse of residential and commercial buildings. Further, people must learn about dos and don’ts when hit by tremors, and authorities should ensure a high level of preparedness to tackle any natural disaster.