Repeated tremors create panic in Sylhet

Frequent earthquakes have created panic among the people of Sylhet as at least seven mild tremors jolted the region recently.

Experts feared that the series of tremors could be a warning sign of a major earthquake in Dauki faultline. About a 300-km faultline stretches south of the Shillong plateau and right at the northern border of Bangladesh's Mymensingh and Sylhet division.

Many people expressed their fear of recurrence of the bigger earthquake that happened on June 12 in 1897.

In 1897, a magnitude 8 plus earthquake jolted in Dauki faultline destroyed many structures of northeastern part of Bangladesh and India’s Meghalaya and Assam. The earthquake struck Sylhet at around 5:15pm on June 12 in 1897 and it had been known as the ‘Great Indian Earth Quake’. 

In Sylhet district, 545 buildings collapsed and a large number of people died. Sylhet experienced some other massive earthquakes in the past.

In 1548, another massive earthquake caused a huge landslide in the Sylhet region. The earthquakes of 1642, 1663, 1812 and 1869 changed the map of Sylhet considerably.

Analysing the past earthquakes of Sylhet region, experts said that in earthquake prone areas, earthquakes occur more frequently after every 100 years. They also said that the Dauki faultline has made the region prone to earthquakes. 

“The Dauki faultline has huge strain energy stored that will be released at any time and can cause 7.5 to 8.5 magnitude earthquake,” said Dr Syed Humayun Akhter, a professor of the Geology Department of Dhaka University and director of Dhaka University Earth Observatory.

“The location of the most of the Sylhet tremors was at the hilly terrain right in the upstream of Sari river in Jaintiapur. It is the eastern part of Dauki faultline.

Dr Jahir Bin Alam, a professor of Civil and Environmental Engineering Dept of Shahjalal University of Science and Technology (SUST), echoed the same as Prof Humayun, saying that the seven recent earthquakes in Sylhet might be a warning signal. 

“It could be due to the climate change or plate shifting. We need to be alert about the possibility of a major earthquake in the next four or five days,” he added.

Abdul Hye Al-Hadi, an environmentalist and a resident of Jaintiapur upazila, told the Bangladesh Post on Friday (June 11) that following the seven recent tremors in their district, they fear recurrence of a major earthquake like the 1897 earthquake that hit Sylhet and other regions.   

Abdul Hye Al-Hadi urged the authorities concerned to carry out regular earthquake drills and training over earthquake to deal with a possible disaster.

Four mild earthquakes hit Sylhet on May 29 in quick succession. Sylhet city dwellers experienced the first mild tremor at 10:36am on that day, a second one-stronger than the first-- at 10:50 am and a third mild one at 11:30 am. Residents of the city experienced the fourth one at 1:58pm on the same day. The second tremor of the day was of the highest magnitude 4.1 in Richter scale.

After the four successive earthquakes in a day, another earthquake jolted the district in the early morning on May 30. The earthquake, measuring 2.8 magnitude on the Richter scale, was felt at 4:35 am on that day. The epicenter of the earthquake was in the bordering area of the district.

After the five successive earthquakes on May 29 and 30, two other earthquakes in two minutes jolted Sylhet on June 7 evening. A building of Raja GC High School in Sylhet city tilted and developed huge cracks following the earthquakes. The tremors spread fresh panic among the people of the district. The epicentre was in South Surma upazila in the district. 

Between January and April in 2020, two consecutive earthquakes originated in Gowainghat upazila in Sylhet near the Dauki faultline.

Saeed Ahmad Chowdhury, chief meteorologist at the Sylhet Meteorological Office, said that after the 1897 bigger earthquake, another earthquake, measuring a magnitude 7.6, originated at Srimangal in Sylhet on July 18 in 1918.

Mominul Islam, in-charge of the Agargaon Earth Observatory, said that an earthquake caused aftershocks and foreshocks. It was a good thing that stored energy was being released through a few tremors. However, he said that Sylhet was at risk of earthquakes.