Dhaka [Bangladesh], November 21 : Dhaka and several parts of Bangladesh experienced strong tremors on Friday morning following a 5.5-magnitude earthquake near Narsingdi, according to the United States Geological Survey (USGS).
The USGS reported that the quake occurred at 10:08 am (IST). Tremors were widely felt in Dhaka around 10:40 am and were also reported in parts of India, including West Bengal and adjoining north east India.
There have been no reports of casualties or damage so far, and authorities have not issued any advisory.
Last month, in October, an earthquake of magnitude 3.4 struck Bangladesh, the National Centre for Seismology (NCS) reported.
Shallow earthquakes like this one tend to cause stronger shaking because seismic waves travel a shorter distance to the surface. According to global seismic data, an earthquake occurs somewhere in the world roughly every 30 seconds, although most are too weak to be detected.\\
The Daily Star, citing USGS figures, reported that a magnitude 4.0 earthquake releases energy equivalent to about 6 tons of TNT, while a magnitude 5.0 earthquake corresponds to around 200 tons. The energy rises sharply with each increase in magnitude: a 7.0 quake equals nearly 199,000 tons of TNT, and a 9.0 quake releases about 99 million tons, comparable to roughly 25,000 nuclear bombs.
Bangladesh sits on a highly active junction of three tectonic plates--the Indian, Eurasian and Burma plates. The Indian plate moves northeast at about 6 cm per year, while the Eurasian plate moves northward at around 2 cm per year over it.
The country lies close to several major fault lines, including the Bogura fault, Tripura fault, Shillong Plateau, Dauki fault and Assam fault, making it part of 13 earthquake-prone zones. Areas such as Chattogram, the Chattogram Hill Tracts and Jaintiapur in Sylhet fall in the highest-risk category.
Dhaka, with more than 30,000 people per square kilometre, is one of the densest cities in the world and has been identified as one of the 20 most earthquake-vulnerable cities globally, according to The Daily Star.