The  20-20-20 rule was developed by our founder, Ron Harrris, as a way to educate at risk communities on common signs of tsunamies. The rule states that if you feel the ground shake for at least 20 seconds, then a tsunami could arrive in the next 20 minutes so you need to get to an elevation of at least 20 meters. 

​

This rule of thumb is taught to those in at risk communities. Although it is simple and easy to remember and understand, it still clearly communicates when to expect tsunamies and how to stay safe.

​

It is also important to note that tsunamis have multiple waves. Although the first is often the most destructive, the waves that follow still have a lot of energy and destructive power. Not all tsunamis are preceded by a recession of the shore line. (see page on tsunamis)