In the event of a local tsunami, the best indicator is the occurrence of a strong earthquake. If you find yourself near a coastline during a major earthquake, you should assume that a tsunami is to follow. Take immediate evasive action as soon as the seeking has ceased. In the event of a distant tsunami, there may be time for authorities to issue a coordinated warning, sometimes via sirens or alert messages to your phone. Alternatively, you may witness a negative wave event prior to the tsunami’s arrival. This is when the tsunami wave’s trough (its lowest point) arrives before the crest (its highest point). Essentially, its like an extreme low tide event in which the ocean suddenly and dramatically retreats. If you see this, run!