The enormously large-scale analysis of data obtained during the 2022 eruption of Hanga Tonga is endless and continues to unravel the secrets of the underwater volcano that produced the most powerful volcanic eruption of modern times. A new study suggests that this may be the trigger for this eruption.
We’ve almost forgotten it and yet, on January 15, 2022, the most powerful eruption ever occurred: the underwater volcano Hanga Tonga-Hunga Ha’apai, located off the coast of the Tonga Peninsula. Scientists remember it well, and for good reason: From start to finish, the eruption was closely monitored, and data collected in just a few hours is still being processed.
An hour before the eruption, a faint seismic signal of 750 km was recorded
These data, of very diverse origins, allow us to better understand the mechanics. ExplosiveExplosive Volcanoes and the results of such powerful eruptions, whether they are related to the atmosphere or the marine environment. However, many points are still mysterious, especially regarding the origin of this volcanic event.
However, a seismic signal recorded minutes before a volcanic eruption can help better understand this critical moment.
Researchers have actually identified the sensible arrival of seismic waves on recordings from two seismological stations located on the islands of Fiji and Futuna, 750 km from the underwater volcano. These are Rayleigh waves, a type of seismic wave that travels through the Earth’s surface. However, they were recorded at 3:45 UTC (Coordinated Universal TimeCoordinated Universal Time), while the eruption started a quarter of an hour later, around 4:00 UTC. For researchers, who present the results of their analyzes in a journal. Geophysical Research Lettersthis discrete seismic signal is directly associated with the eruption and indicates that an event occurred long before it was triggered. And if it was exactly that factor that caused the explosion. BoilerBoiler ?
A rift opening in the oceanic crust
For researchers, it is entirely possible. This could have been caused by the opening of a fracture in the precursor signal. Oceanic crustOceanic crust Beneath the caldera of the already active volcano, around 3:45 p.m MagmaMagma Rises in the crack, sea water seeps in. However, the collision between cold water and magma is particularly explosive! This is the meeting that may have led to the violent explosion of Hanga Tonga at 4:00 am.
Findings that help understand the stages of this eruption, but which may also have implications for early detection of underwater eruptions.
