Slow earthquakes are long-period earthquakes that are not so dangerous alone, but are able to trigger more destructive earthquakes. Their origins lie in tectonic plate boundaries where one plate subsides below another. Though the causal mechanism is already known, there has been a lack of data to accurately model the life cycle of slow earthquakes. For the first time, researchers use deep-sea boreholes to gauge pressures far below the seafloor. They hope data from this and future observations can aid the understanding of earthquake evolution.
The surface of the Earth lies upon gargantuan tectonic plates. The edges of these interact in different ways depending on the plates’ relative movement, composition and density. Where plates collide and one sinks below another is known as a subduction zone, often the site of what are known as slow earthquakes. These are low-frequency earthquakes which release their energy over longer periods — hours to months — than the earthquakes we might feel shaking the ground beneath us, which can last seconds to minutes.
Read more at University of Tokyo
Image: The team prepare the deep-sea drill for use on the seafloor. (Credit: © 2021 JAMSTEC-IODP)