by During the midday prayers on March 28th, an earthquake of the strength 7.7 in central -Myanmar met along the Sagaing Reflection.
With an epicenter near Mandalay, the second largest city in the country, it was the most powerful earthquake that Myanmar has been roaming since 1912. This led to a widespread destruction of Mandalay’s infrastructure, while the reports gave the fatalities between 3,700 and more than 5,000 people.
His seismic effects achieved to Bangkok, Thailand’s capital, in which she collapsed a 30-story skyscraper and claimed at least 92 lives.
Could seismologists see it coming?
Scientists had expected a large earthquake along a fault, which had not been broken since a similarly destructive earthquake in 1839.
But what they could not predict was when the earthquake, its epicenter or how destructive it would be.
“Despite decades of efforts, scientists still cannot reliably predict when and where earthquakes will strike,” said Kit Yates, a mathematician at the University of Bath, Great Britain.
“The movements and interactions of the tectonic plates of the earth are incredibly complex. The distinction between sensible earthquake warning signs due to seismic background noise – especially with additional human activities – is extremely difficult,” Yates told DW.
Five months after Mandalay’s quake, scientists have analyzed their destructive effects – and their results could help to predict features of earthquakes in the future.
“Hope is that such [findings] Could be used to predict the time, size and scope of future earthquakes, “said Jean-Philippe Avouac, seismologist at the California Institute of Technology, US, which was led by a new study this week published in the PASS magazine.
Why was Mandalay’s earthquake so destructive?
Real-time film material of the quake showed the movement of the sagaing error in breathtaking details. The mandalay quake hit like a faster, pulse-like break along the fault line. Under the feet of the people, the floor in the epicenter moved three meters from each other only 1.3 seconds.
Overall, the quake lasted 80 seconds and extended over the error by 460 km (285 miles), which the surface shift of six meters (20 feet) deep.
The Avouac team compared this data with similar features with previous earthquakes. Then they created a computer model that contained several predictions about the sagaing error.
The main component of the model was, as tectonic changes, which were caused by past earthquakes. Avouac described this as a “memory effect” in Sagaing error.
“This is a nice result to show that our simple model leads to a memory effect [and] right with [real world] Observations, “said Avouac.
The model confirmed that a “Supershear” break that reinforced waves in the direction of the split – was expected on the mistake due to its very straight geometry and its history.
Their model forecasts predict that earthquakes in large size and with an interval of around 141 years along the sagaing fault, what does the next quake for Myanmar in 2166 may be 40 years.
The model also identified features of the “Slip” error, with which the forecasts for future ruptures are refined.
The break along the sagaing error was unusually long and even.Hla myo aung/afp
Earthquake forecasts, no predictions
Instead of predicting quake forecasts, seismologists focus on the forecast of seismic activity with better accuracy. Similar to weather forecasts, they want to estimate the probability of earthquakes over longer periods and in certain regions.
“There are consistent relationships between the frequency and energy of the earthquakes. This enables scientists to appreciate how often large quakes can occur on smaller ones, for which more data are available,” said Yates.
The hope is that models such as avouacs could be used to predict time, size and extent of future earthquakes.
“Such forecasts are of crucial importance for disaster planning. A city like San Francisco with a high probability of a great quake in the next 30 years can justify great investments in preparation,” said Yates.
Earthquake forecasts still have “great uncertainties”
Current models “can only carry out probabilistic danger reviews with great uncertainties,” said Avouac.
According to Avouac, scientists are currently unable to predict the time, the place and size of a future earthquake with sufficient precision to take measures, e.g. B. the evacuation of a city.
Earthquakes are chaotic events, which means that even tiny changes in the initial conditions can lead to unpredictable changes in seismic activity.
“The challenge is that the model must currently be tailored to the condition of the error, but we do not know how to measure the distribution of trade fairs [tectonic] Stress and not enough know [about] Last breaks to reconstruct them, “said Avouac.
Researchers currently want to better understand how seismic activities can lead to different types of earthquakes, hoping that they will lead to more precise danger reviews in the future.
Published by: MW Agius
