Scientists say earthquake prediction is impossible, but studying the 2025 Myanmar earthquake may help forecast when and where the next big tremor could strike.During the midday prayers on March 28, a magnitude 7.7 earthquake struck central Myanmar along the Sagaing Fault. With an epicenter close to Mandalay, the country’s second-largest city, it was the most powerful earthquake to strike Myanmar since 1912. It caused widespread destruction of Mandalay’s infrastructure while reports have put the death toll between 3,700 and more than 5,000 people. Its seismic impacts reached as far as Bangkok, Thailand’s capital, where it collapsed a 30-story skyscraper, claiming at least 92 lives. Could seismologists have seen it coming?Scientists had been anticipating a large earthquake along a segment of the fault, which had not ruptured since a similarly destructive earthquake in 1839. But they couldn’t predict when the earthquake would hit, its epicenter or how destructive it would be. “Despite decades of effort, scientists still can’t reliably predict exactly when and where earthquakes will strike,” Kit Yates, a mathematician at the University of Bath in the UK, told DW.“The movements and interactions of the Earth’s tectonic plates are incredibly complex. Distinguishing meaningful earthquake warning signs from background seismic noise, especially with added human activity, is extremely difficult.”Five months after the Mandalay quake, scientists have been analyzing its destructive effects. Their findings could help predict features of earthquakes in the future.“The hope is that such [findings] might be used to forecast the time, magnitude and extent of future earthquakes,” said Jean-Philippe Avouac, a seismologist at California Institute of Technology, US, who led a new study published this week in the journal PNAS.Why was the Mandalay earthquake so destructive?Real-time footage of the quake revealed the Sagaing Fault’s movement in stunning detail. The Mandalay quake hit like a rapid, pulse-like rupture along the fault line. Beneath people’s feet, the ground moved three meters apart in just 1.3 seconds at the epicenter.In total the quake lasted 80 seconds, extending 460km (285 miles) down the fault, causing surface displacement six meters (20 feet) deep.Avouac’s team compared this data to past earthquakes with similar features. They then created a computer model that contained several predictions about the Sagaing Fault.The key ingredient of the model was its description of tectonic changes caused by past earthquakes. Avouac described this as a “memory effect” in the Sagaing Fault.“This is a nice result to show that our simple model results in a memory effect [and] is consistent with [real world] observations,” Avouac said.The model confirmed that a “supershear” rupture — which has amplified waves in the direction of the split — was anticipated on the fault because of its very straight geometry and its history of similar ruptures.Their model forecasts that large-magnitude earthquakes occur along the Sagaing Fault irregularly and with an interval of around 141 years — meaning the next quake to hit Myanmar could be in 2166, give or take 40 years.The model also identified features of the fault “slip” that help refine forecasts about future ruptures. Earthquake forecasts, not predictionsInstead of predicting quakes, seismologists are focused on forecasting seismic activity with better accuracy. Much like weather forecasts, they aim to estimate the likelihood of earthquakes over more extended periods and in specific regions.“There are consistent relationships between the frequency and energy of earthquakes. This allows scientists to estimate how often large quakes might occur based on smaller ones, for which there is more data,” said Yates.The hope is that models like Avouac’s might be used to forecast the time, magnitude and extent of future earthquakes.“Such forecasts are crucial for disaster planning. A city like San Francisco, with a high probability of a major quake in the next 30 years, can justify major investment in preparedness,” Yates said.Earthquake forecasts still have ‘large uncertainties’Current models “can only make probabilistic hazard assessments with large uncertainties,” said Avouac.Avouac said scientists are currently unable to forecast the time, location and magnitude of a future earthquake with enough precision to take action, like order evacuation of a city.Earthquakes are chaotic events, meaning even tiny changes in the initial conditions can lead to unpredictable shifts in seismic activity.“The challenge is that the model needs to be tuned to the state of the fault at present, but we don’t know how to measure the distribution of [tectonic] stress, and don’t know enough [about] past ruptures to reconstruct them,” Avouac said.Researchers are currently aiming to better understand how seismic activity can lead to different types of earthquakes in the hope they’ll lead to more accurate hazard assessments in the future.
