The quake was felt 8 to 10 times in two consecutive days in Sylhet, causing some panic among the common people. The Housing and Building Research Center (HBRC) is closely monitoring the issue and feels the need to share some issues with everyone. We can learn two things from the analysis of experts given in the media. Firstly, small earthquakes can be an early warning of a large earthquake and secondly, they can reduce the tendency and intensity of potential earthquakes in the future by releasing some of the long-term stored pressure.
HBRC’s analysis on the subject:
Before and after large or medium earthquakes there are usually some small earthquakes, which we call pre-shock and after-shock. With this in mind, we can consider these earthquakes as a precaution for moderate or large earthquakes.
The idea of reducing the magnitude of possible future earthquakes by releasing some of the long-term stored stress cannot be dismissed as inaccurate. However, there is considerable doubt as to how much security will be ensured by reducing the amount of energy. From the concept of magnitude, vibration, and energy emission on the Richter scale, we find that for every 1 magnitude increase, the magnitude of the earthquake increases 10 times, but for every 2 magnitude, the magnitude of the force increases 32 times, and for every 2 magnitude, the magnitude increases to 1000 times.
In other words, the energy emitted in a 4 magnitude earthquake is 1000 times more than the energy emitted in a 6 magnitude earthquake and the amount of energy emitted in a 6 magnitude earthquake is 1 million times more. So, there is a rough idea of how much pressure will be released in small earthquakes.
It would be astute for us to consider the seismic tremors of the most recent two days as a notice indication of a huge or moderate quake and make the fundamental arrangements.
For this situation we need to receive in any event three level arrangement.
To start with, crisis readiness arranging.
Second, momentary designs to decrease seismic tremor hazard.
Third, long-haul arranging.
The plan of action to deal with emergencies is mainly to raise awareness of earthquake risk reduction at all levels of people and the necessary advance preparation of all organizations involved in search and rescue operations. One of the reasons for raising awareness may be the widespread dissemination of ‘Permanent Disaster Orders’ guidelines on what to do before, during, and after an earthquake.
