A locally generated tsunami may reach a nearby shore in less than ten minutes. There may not be sufficient time for tsunami warning centers, such as the Pacific Tsunami Warning Center, or for local authorities to issue a warning. For people living near the coast, the shaking of the ground from an earthquake is nature's natural warning that a tsunami may be imminent. Observation of unusual ocean changes, or the hearing of loud ocean roars are also nature's natural tsunami warning signs. If you sense of these and are near the occean, evacuate immediately inland and to higher ground.
For tsunamis from more distant sources, however, tsunami warning centers play an important role in ensuring public safety. Accurate warnings of when a tsunami might arrive are possible because tsunamis travel at a known speed. Warning centers will work with local authorities to advise them on whether a tsunami will impact their coasts.