Who Should Speak About Earthquakes?

In recent weeks, public anxiety about possible earthquakes in Bangladesh -- especially in Dhaka -- has increased sharply. Much of this fear is being fueled by alarming statements in traditional and social media.

To understand the real situation, it is essential to know how earthquake risk is actually studied and which institutions are responsible for informing the public and the government.

In 1979, an earthquake zoning map of Bangladesh (Fig. 1) was prepared along with a detailed report. The first official tectonic map of Bangladesh (Fig. 2) was produced in 1991 by the same department -- the Geological Survey of Bangladesh (GSB), the national agency responsible for studying the Earth’s structure and subsurface features.

These works were carried out by geoscientific experts from GSB in collaboration with specialists from universities, other organizations, and even the USGS.

The primary purpose of these maps was to guide safe construction practices and support the development of the national building code. In addition, earthquake hazard assessments across the country were also key objectives in producing the maps.       

Fig. 1. Earthquake zoning map of Bangladesh.                                                                  

 Fig. 2. Tectonic Map of Bangladesh.                                                                                         

In later years, a few studies have proposed the existence of megathrusts, plate boundaries, or subduction zones (Fig. 3) beneath Bangladesh, based primarily on computer models using gravity, magnetic, and GPS data -- without direct field confirmation or comprehensive analysis of other supporting datasets.

However, many geoscientists have continued to rely on this map (Fig. 3), assuming it to be a true representation of the tectonic elements of Bangladesh.

While scientific models are valuable, they remain theoretical until validated through extensive field-based investigations. When such unverified or misunderstood information is presented dramatically by media outlets or social media influencers, it creates unnecessary panic.

This not only frightens the public but also misleads policymakers and complicates decision-making.

Fig. 3. Topographic map of Ganges–Brahmaputra Delta and Burma Arc region showing tectonic features. Major faults and tectonic boundaries are indicated by heavy black lines, adopted from Stechler et al, 2008.

To assess earthquake risk, scientists consider many factors, including fault lines, plate movements, rupture lengths, underground rock structures, and historical earthquake records.

This information comes from geological, geophysical, and seismic research -- not from surface-level observations or unrelated data.

It is also important to understand that the impact of an earthquake does not depend solely on its magnitude. Building quality, construction practices, population density, and soil conditions play equally important roles.

This is why a moderate earthquake of around magnitude 5.5 can cause serious damage in a densely populated area with weak construction practices, while the same event may cause minimal damage in cities like Tokyo, Hong Kong, or San Francisco, where strict building codes are implemented and enforced.

Due to the recent earthquake near Dhaka, the capital of Bangladesh, some social media activists and even prominent public figures are attempting to predict earthquakes by misinterpreting complex tectonic maps that do not accurately represent the subsurface geological conditions of the country.

Tectonic maps are highly technical and difficult for the general public to understand. In some cases, even geoscientists have used questionable or incomplete datasets to predict extremely large earthquakes -- sometimes as high as magnitude 9. These claims are not based on fully verified, ground-tested evidence.

Globally, responsibilities are clearly defined: water-related information comes from water authorities, weather-related information comes from meteorological departments, and underground seismic matters are handled by geological or earth science agencies.

In Bangladesh, however, earthquake-related communication is often delivered through the Weather Department, although it neither studies the Earth’s interior nor conducts earthquake-related research. 

From a scientific and international-practice perspective, responsibility for earthquake and tectonic matters should logically rest with the Geological Survey of Bangladesh.

The truth is simple: Accurate earthquake prediction is extremely complex and has not yet been achieved anywhere in the world. No country can reliably predict the exact time, location, or magnitude of an earthquake.

What scientists can do is identify risk zones and recommend safer building practices. This requires long-term, detailed, field-based research -- which remains limited in Bangladesh.

Based on existing geological datasuch as known fault rupture lengths, the absence of mega-thrust faults or active subduction zones within Bangladeshi territory, and historical earthquake records -- there is currently no scientific basis for predicting an earthquake exceeding magnitude 6 inside Bangladesh.

Bangladesh’s basement is composed of continental crust and oceanic crust that are both integral parts of the Indian Plate, not separate tectonic plates.

Instead of spreading fear, the right approach is to:

• Strengthen and enforce building codes
• Conduct proper geological and seismic research
• Educate the public on earthquake safety
• Assign clear responsibility to the appropriate scientific authority
• Establish a dedicated earthquake information website under the Geological Survey of Bangladesh to prevent misinformation and fake predictions

If the government is serious about reducing earthquake risk, it should immediately form a national task force of experts, led by the Geological Survey of Bangladesh, to begin coordinated research and implement an effective risk-reduction program. Panic does not save lives -- preparation and proper planning do.

Sirajur Rahman Khan is the Director General (Retd), Geological Survey of Bangladesh, and Ex-Professor of the Department of Oceanography, University of Dhaka.