## Earthquake Awareness > [!INFO]- YouTube > <center><iframe width="560" height="315" src="https://www.youtube.com/embed/9kcqPguyAR8" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe></center> - Evelyn Roeloffs, geophysicist - Three types of earthquakes can affect Portland - Giant subduction zone earthquakes along the coast, as large as magnitude 9 - Subduction zones produce world's largest magnitude earthquakes because the plate can't slide smoothly under the continent - Geologists found evidence of at least 8 tsunamis/earthquakes in the last eight thousand years, but most were closer to California - Most recent was on January 26, 1700 - Every 400–600 years (on average) - Earthquake would be similar to one in Japan, March 2011 - crustal earthquakes as large as 7, much closer and relatively shallow - Similar to Christchurch, New Zealand earthquake February 2011 - Deep intraplate earthquakes directly under Portland, magnitude 6.5, 20 miles deep - 2001 "Masquale"(?) Puget Sound earthquake - Strength of shaking depends not just on magnitude but proximity - Earthquakes are always followed by aftershocks within a magnitude of the first —and sometimes larger - Aftershocks can continue for weeks or years?! - Biggest risk factors are pre-1990s construction - [x] [[N2 NET Volunteer Training Videos 20231114|Continue NET volunteer training]] with [[#9. Earthquake Awareness|next video]] 📅 2023-12-15 ✅ 2023-12-07 --- - [[N2.21 Portland NET Basic Training Index 20240120|Portland NET Basic Training]]