Certain submarine earthquakes occur with almost perfect regularity over decades.
An international team of researchers claims to have solved one of the most persistent mysteries of modern seismology: the reason why certain Undersea earthquakes occur with almost perfect regularity over decades.
The identified a set of geological mechanisms that function as “natural brakes”, preventing certain earthquakes from reaching potentially more destructive magnitudes.
The phenomenon was observed on the Gofar fault, located in the Pacific Ocean, about 1,600 kilometers west of the coast of Ecuador. In this region, scientists recorded, for more than 30 years, earthquakes of magnitude close to 6 that recur approximately every five or six years, almost always appearing in the same areas and with similar intensity. This unusual regularity led researchers to seek an explanation for the fault’s seemingly predictable behavior.
The research was based on data collected by seismometers installed on the seabed during two scientific campaigns carried out between 2008 and 2022. The equipment recorded tens of thousands of small tremors before and after two large earthquakes, allowing experts to observe in detail the evolution of seismic activity in the region.
The results revealed the existence of intermediate zones, designated by the researchers as “structural barriers”, located between the most active segments of the fault.
These areas have a complex geological configuration, marked by multiple fractures and the infiltration of seawater at depth, details the .
When a seismic rupture hits one of these zones, there is a sudden drop in pressure in the fluids present in the rocks, causing a temporary hardening of the structure.
This process, known as “strengthening by dilatancy”acts as a natural brake capable of slowing down or stopping the spread of the earthquake.
According to the authors, these barriers are not simple inactive areas, but dynamic elements that play a determining role in limiting the size of earthquakes.
Although the Gofar fault is far from densely populated areas, researchers believe similar mechanisms may exist in other submarine faults.
