The soil that becomes similar to mobile sands, collapsing any building or infrastructure is above. While the victims of the 7.7 magnitude earthquake are counted – followed 12 minutes away from a second shock of 6.4 – which hit Myanmar with a devastating power, the experts speak of “risk of liquefaction of the soil”. “If even in Bangkok, which is located on several hundred kilometers away, there have been collapses, inside the epicentral area there will certainly be great destruction, many landslides and liquefaction phenomena”, explains the president of the National Institute of Geophysics and Volcanology, Carlo Doglioni. That is, he continues, “the shaking of the soil that seems solid, liquefies and if there are homes above these they collapse and there may be further damage”.
What is the liquefaction of the ground and why it can have a destructive impact
What exactly is it about? Liquefaction is a phenomenon that occurs in conjunction with seismic events of a certain intensity, with a magnitude generally greater than 5.5-6.0. It manifests itself due to an increase in interstitial pressure, or the pressure that water normally exerts in the land.
Under normal conditions, this pressure does not come to overcome the resistance to the deformation of the soil, but in the case of powerful seismic shocks it may happen that the grains of sediment that make up the soil begin to move, making the ground lose cohesion and behave like a fluid.
https://www.youtube.com/watch?v=19ujjfxlgyu
This involves heavy impacts on the infrastructures that are above, explains Salvatore Stramondo, research manager of the Ingv. The ground takes to behave “similarly to mobile sands”, putting at risk the stability of the structures on the surface, greatly altering the landscape. The phenomenon of liquefaction was also recorded in conjunction with the seismic events that affected Emilia-Romagna in 2012.
What can happen in the next few hours
Professor Doglioni then clarified the reason for the devastating power of the earthquake. It is “an area of the world where the Indian plaque moves north-northeast under Asia and in that area of Burma it has an oblique component, they are earthquakes that have a compressive component but also of lateral movement between the plates what we call right transpression”.
Therefore, “the effect of this oblique convergence between India and Asia of about 4 cm per year, speed 10 times larger than those we have in Italy where the deformation is of the order of millimeters per year: this explains why there are much more energetic earthquakes there than with us”, clarifies Doglioni.
Magnitude 7.7 Earthquake in Myanmar,
– Science girl (@gunsnrosgesgirl3) March 28, 2025
What happened is called a “main shock, that is, a main shock”, explains the president of the Ingv and it may happen that the main shocks are accompanied by others of magnitude similar to a few hours. “There is a sequence that decays over the days in terms of number of shocks of magnitude that become smaller and more increasingly branched. But if the descent has begun definitively we do not know – clarifies – because if there is a further resurgence, with another main shock, the clock is re -tanned”.