The earthquake prediction is overly conjectural
Recent media report on the possibility of a giant earthquake in Bangladesh that could put millions at risk and make Dhaka unliveable, as per a research study, has stirred up panic and controversy in the public domain. The report is based on a research paper entitled "Locked and loading megathrust linked to active subduction beneath the Indo-Burman Ranges." published recently in the online jounal Geoscience nature.
While the paper is based on the research of a group of geoscientists with upscale technologies like GPS, the interpretations, as published in newspapers, have been overly conjectural. For example, the position of the plate boundary shown as the mega thrust has been shifted west to a significant distance and is placed to run right underneath the Dhaka city. There is no geological evidence to justify the existence the mega thrust running through the Bengal plain and Dhaka city as shown in the study. It is only a conjecture that geoscientists have put forward. But more importantly, making predictions of an unprecedented mega disaster based on such conjectural elements is even less acceptable.
A news reported quoted one of the co-authors of the paper, an academician in Bangladesh, as follows:
"Mud that has accumulated some 12 miles (19 km) deep in the delta of the Ganges and Brahmaputra rivers could shake like gelatin, and liquefy in many places, sucking in buildings, roads and people."
The above statement is not only unrealistic, but sounds like a fantasy. None of the deep oil and gas wells drilled in the Ganges-Brammaputra delta encountered 19 kilometres of mud. In the subsurface, the rocks down to about 5 m were drilled and these are found to be hard rock layers and include alternating sandstone and mudstone (shale). Liquefaction is a fact of earthquake geology, but not to the extent the statement suggests.
Bangladesh is positioned in the vicinity of a tectonic plate junction, and is therefore, likely to be more earthquake prone than an average area. But the report has been monstrously over-emphatic in its judgement of risk of Dhaka city. The suggestion that the "giant earthquake would make Dhaka unlivable" is also overly pessimistic and gives a negative signal to an aspiring mass of people who struggle to be industrially prosperous.
We appreciate academic research which links important national issues, disaster related or otherwise, but one should be more cautious in publicly commenting on the results and interpretations of scientific research. Scientific hypothesis or conjectures should not be translated into a pointed practical prediction that would spread unnecessarily spread panic among the public.
The writer is Professor, Department of Geology, University of Dhaka.