Doublet earthquake

A doublet earthquake is a special kind of earthquake that happens when two big shakes occur very close together in the same place. These shakes are almost the same size, which makes them different from smaller shakes that usually follow a big quake.

These earthquakes happen because parts deep in the Earth called asperities stop the shake from moving smoothly. This lets only a little bit of pressure go away at first, and then another big shake can happen soon after.

Scientists learned about doublet earthquakes in the 1970s and 1980s. Studying them helps us understand how Earth moves and shakes better. Even though they can be surprising, they teach us important things about our planet.