A huge earthquake may be building beneath Bangladesh, the most densely populated nation on earth. Scientists say they have new evidence of increasing strain there, where two tectonic plates underlie the world’s largest river delta. They estimate that at least 140 million people in the region could be affected if the boundary ruptures; the destruction could come not only from the direct results of shaking, but changes in the courses of great rivers, and in the level of land already perilously close to sea level.
The newly identified threat is a subduction zone, where one section of earth’s crust, or tectonic plate, is slowly thrusting under another. All of earth’s biggest known earthquakes occur along such zones; these include the Indian Ocean quake and tsunami that killed some 230,000 people in 2004, and the 2011 Tohoku quake and tsunami off Japan, which swept away more than 20,000 and caused the Fukushima nuclear disaster. The findings appear in this week’s issue of Nature Geoscience.
Is the country ready for this quake?
Akhter says that fast-growing, poor Bangladesh is unprepared; no building codes existed before 1993, and even now, shoddy new construction flouts regulations. Past quake damages and deaths are no indicator of what could happen now, he said; population and infrastructure have grown so fast that even fairly moderate events like those of past centuries could be mega-disasters. “Bangladesh is overpopulated everywhere,” he said. “All the natural gas fields, heavy industries and electric power plants are located close to potential earthquakes, and they are likely to be destroyed. In Dhaka, the catastrophic picture will be beyond our imagination, and could even lead to abandonment of the city.”