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.