Newport Tide Gauge Shows Kamchatka Tsunami Wave Energy Resonating Around the Pacific for Days

by Brian Bahouth

If you look at the NOAA online Tides and Currents prediction graph for Yaquina Bay, Oregon, the thin blue line undulates from low to high, and when you add the data for actual tide levels to the graph, a smooth red line virtually mirrors the highly accurate NOAA prediction. But roughly 7 hours after the Kamchatka earthquake on July 29, the usually smooth red line of actual tide data in the Yaquina Bay began to rise and lower by some 6 to 8 inches every 20 minutes or so.

The gradually decreasing oscillation continued for days and by August 4 had mostly subsided .

To learn what’s behind this distinct change in Yaquina Bay tide data, we turned to Dr. Chris Goldfinger, Professor Emeritus, College of Earth, Ocean and Atmospheric Sciences at Oregon State University.

“The deviations from predicted are most likely resonance of the tsunami energy bouncing around the Pacific basin, and possibly within the harbor itself, this goes on for days as you can see, as the waves reflect and refract around the Pacific,” Dr. Goldfinger wrote in an email.

This striking video shows how tsunami wave energy from the Kamchatka earthquake propagated around the vast Pacific ocean.   

Dr. Goldfinger added that wave reverberations can pose an unexpected hazard.

“This is in part why tsunami warnings are not taken down for quite a while after the first arrival.  People may wonder about that and think it’s just caution to the extreme, but it’s not, it’s possible for significant waves to arrive hours after the early large ones and catch people by surprise. This happened in Chile in 2010.”