Learning and teaching resources on Cascadia (northern California, Oregon, Washington, and southern British Columbia) earthquakes and tsunamis are provided in this section. The scientific detective story of Cascadia tsunami geology and the orphan tsunami of 1700 observed in Japan are central themes. WE also explain how Global Positioning System (GPS) data demonstrate that the Cascadia continental margin is storing elastic energy that will be released in the next great Cascadia earthquake with the resulting tsunami arriving onshore within 30 minutes. In addition to great subduction zone earthquakes, Cascadia also experiences “deep” earthquakes that occur within the subducting Juan de Fuca Plate and crustal earthquakes on faults that some times lie beneath densely-populated cities. These three kinds of Cascadia earthquakes present three distinct sets of challenges to earthquake preparedness. Finally, we the introduce learners to the newly discovered phenomenon of Episodic Tremor and Slip (ETS) and explain how motions of the Juan de Fuca and North American plates cause ETS in Cascadia.
We recommend that you start learning about Cascadia Earthquakes and Tsunamis using the TOTLE web site by viewing the Cascadia Earthquakes and Tsunamis PowerPoint Presentation. This presentation provides the basic concepts and observations as well as links to teaching resources appropriate for a middle school audience.
A PDF Guide to Cascadia Earthquakes and Tsunamis is also available. This guide is an outline of the Cascadia Earthquakes and Tsunamis topic that contains links to and a table of contents of TOTLE teaching resources on this topic.
Roger Groom (Science teacher at Mt Tabor Middle School in Portland, OR) explains the organization of the Cascadia GPS Gumdrop Lesson Plan. Part 1 explains the materials and construction of the gumdrop model of a GPS receiver. Part 2 explains a classroom demonstration showing how distances from three GPS satellite to a GPS receiver uniquely locates that receiver location.
Roger Groom (Science teacher at Mt Tabor Middle School in Portland, OR) explains Parts 3, 4, and 5 of the Cascadia GPS Gumdrop Lesson Plan. Part 3 deals with how time-series graphs show the motion of a GPS receiving station. Part 4 shows how to help students determine the direction and rate of movement of a GPS receiver from the time-series graphs.