Earthquakes strike without warning, often with devastating consequences. The tremors in Bangladesh on Friday (21 November), Afghanistan in August this year, and Turkey and Syria in 2023 underscore how unpredictable they remain.
A massive tremor struck at 10:38am, shaking several districts in Bangladesh including Dhaka as well as parts of India. The Bangladesh Meteorological Department reported the magnitude of 5.7.
At least 10 people were killed and more than 600 injured on Bangladesh on Friday. More than 1,400 people were killed in Afghanistan in August. Two devastating earthquakes have claimed thousands of lives and left many more injured or without shelter in Turkey and Syria in 2023.
However, scientists still cannot forecast when a major earthquake will occur.
The Earth’s crust is divided into massive tectonic plates that constantly shift over hot, moving rock beneath. These plates usually remain locked, accumulating stress until something deep underground snaps.
The sudden release of pressure sends energy surging through surrounding rock along fractured lines called faults. While this mechanism is well understood, predicting when a fault will fail remains elusive.
Earthquake strength is measured on the Richter scale, which runs from 1 to 10. A quake of magnitude 6 is classified as strong—it can cause objects to topple and damage to houses.
How do we know if an earthquake is coming?
Seismographs, GPS-linked surface sensors and satellite tools like InSAR allow scientists to map earthquake size, location and ground deformation with remarkable accuracy after an event.
Machine learning now analyses massive datasets to detect subtle signals faster than humans can. Still, as experts note, the problem lies beneath the surface. Tim Wright of the UK-based Centre for Observation and Modelling of Earthquakes, Volcanoes and Tectonics (COMET) said, “We aren’t anywhere near a short-term forecast.”
Laboratory experiments offer some hope. Using granite blocks to simulate faults, researchers can predict “labquakes” by tracking small cracks and changing elastic properties. “We’d love to port this to the Earth, but we are not there yet,” said Chris Marone of Sapienza University of Rome and Penn State University.
Real-world faults, such as the East Anatolian system where three tectonic plates converge, are far more complex. Although many believed the region was “overdue” for a large earthquake, scientists could not pinpoint when it would strike.
According to the United States Geological Survey (USGS), useful prediction requires knowing the exact location, timing and magnitude of a future quake – something no current method can deliver. The USGS records global seismic events and maintains a webpage devoted to debunking prediction myths.
Researchers are experimenting with numerous potential signals, including electrical disturbances in the ionosphere, water vapour changes, gravity ripples and even animal behaviour.
China’s satellite-based monitoring has detected electron density drops days before some quakes, but scientists caution that these signs remain inconsistent and difficult to interpret. As Mei Li of the China Earthquake Network Centre noted, “We cannot specify the right location where a forthcoming event will happen.”
Even as prediction remains out of reach, engineering advances offer protection. At the University at Buffalo’s earthquake simulation lab, engineers design structures that can withstand major quakes by directing damage to replaceable components.
Meanwhile, artificial intelligence is helping responders map destruction from satellite images and assess aftershock risks.
For now, as experts repeatedly warn, earthquakes will continue to surprise. The science is advancing but the Earth continues to keep many of its secrets hidden deep below.
