The eruption of Hunga Tonga-Hunga Ha’apai volcano earlier this year created a tsunami that spread to Washington’s coasts. This may have been the first tsunami many residents of Washington had experienced, but it might not be the last. Tsunamis occur pretty frequently, with two damaging tsunamis occurring worldwide each year on average. In Washington State, there are multiple sources both near and far that can produce tsunamis that affect the state’s coastlines. The nearby Cascadia subduction zone has caused giant earthquakes and tsunamis in the past, but other crustal faults or landslides into Puget Sound have also caused tsunamis, and distant earthquakes in Alaska (or volcanoes across the Pacific!) have created tsunamis that traverse the ocean. You can read more about past tsunami events that impacted Washington here.
As residents of Washington State, and citizens of the world at large, it’s important to be aware of tsunami hazard zones and how to best prepare yourself for tsunami hazards. Whether you regularly frequent a tsunami hazard zone or not, knowing the natural warning signs of an impending tsunami can save your life. That’s exactly what happened for Tilly Smith, a 10-year-old girl from England who was on vacation in Thailand during December of 2004. Tilly noticed the ocean behaving in a strange fashion, and notified her parents that she thought a tsunami might be coming. Sure enough, her keen observations and quick thinking resulted in many lives being saved at the beach that day.
To help you and your school-aged children acquaint yourself with tsunami science and tsunami preparedness, we are releasing a Tsunami Interactive Web Guide for the content on our Tsunami webpage. The web guide is aimed at grades 6 and above, but can be adapted for other age groups.
The web guide includes four sections to learn about the basics of what tsunamis are and how they form, evidence for past tsunamis in the state, an introduction to the tsunami modeling products that we offer at the Washington Geological Survey, and emergency preparedness information for tsunami hazards. There is also a glossary of terms at the end of the web guide.
After working through the web guide, there is also a Capstone Project, where you can imagine that you get to travel back in time and space to Washington’s coast in January 1964, three months before the large Alaska earthquake and tsunami that impacted the west coast of the country in March 1964 (read firsthand accounts of Washington residents from the 1964 tsunami here). There are two options for the Capstone Project, where you can think about tsunami preparedness from two different perspectives and summarize your learning with a creative product. In one option, you can consider how you can help prepare the coastal community of Ilwaco in 1964 for the incoming tsunami. The other option is to focus on the warning system measurement and communication technology that was available during 1964 and today (see image below), compare the differences in how the hazard was recorded and communicated, and identify what improvements still need to be made.
There is also an additional Data Component for this tsunami curriculum. Students can look at real-time tide gauge data, learn about tides and how water levels are measured, and think about what a tsunami looks like when recorded by a tide gauge. Students can also look at tsunami travel time maps from historical events like the 2011 Japan earthquake and tsunami (see image below), and look at the tide gauge data from that event from many different places around the world.
WASHINGTON STATE GEOLOGY NEWS 