Learning and teaching resources on hazards posed by earthquakes and tsunami and methods for mitigating those hazards are provided in this section. The treatment of earthquake hazards and damage highlights the main factors that control the violence of ground shaking produced by earthquakes. These include: earthquake magnitude; distance from the earthquake; local geology; building style; and duration of ground shaking. Using lesson plans provided, students can explore engineering approaches that minimize building damage from earthquake ground shaking. Basic concepts and properties of tsunami include: generation of tsunami by shallow great earthquakes at subduction zones; speed and travel times of tsunami in deep ocean and amplification of wave height upon landfall; and the contrast in time available for evacuation from a distant tsunami compared to a local tsunami.
To efficiently learn about Earthquake and Tsunami Hazards using the TOTLE web site and to locate teaching resources on this topic, we recommend that you start by viewing the PowerPoint presentations. First-time users should download and view these presentations to understand the logical sequence of observations and concepts. The presentation Earthquake Hazards PowerPoint Presentation provides fundamental concepts of earthquake damage and mitigation along with links the teaching resources for a middle school audience. The Tsunamis PowerPoint Presentation provides background information and links to tsunami teaching resources.
A PDF Guide to Earthquake and Tsunami Hazards is also available. This guide is an outline of the Earthquake and Tsunami Hazards topic. The guide contains links to TOTLE Earthquake ad Tsunami Hazards teaching resources and a table of contents of teaching resources on this topic.
The simplest form of base isolation uses flexible pads between the base of the building and the ground. When the ground shakes, inertia holds the building nearly stationary while the ground below oscillates in large vibrations. Thus, no force is transferred to the building due to the shaking of the ground. The flexible pads are called base-isolators and structures using these devices are called base-isolated buildings.
Building Oscillation Seismic Simulation, or BOSS, is an opportunity for students to explore the phenomenon of resonance of buildings that experience earthquake shaking. All buildings have a natural “resonance” frequency. If a building is shaken at this frequency, it will oscillate with large amplitude and may be severely damaged or destroyed. If the same building is shaken at either lower or higher frequencies, it will oscillate with smaller amplitudes and may withstand earthquake shaking without significant damage.
The classroom activity is from “Unit 4. Can Buildings Be Made Safer?” of the five-part Seismic Sleuths earthquake guide. The lesson ids “designed to allow students to construct an understanding of how buildings respond to earthquakes. Lessons on design and how earthquake forces act on various designs provide students with information on how to build earthquake resistance structures.”
This role-playing activity was adapted by Michael Clapp, Battleground School District from a Washington State Department of Emergency Management document. The activity focuses specifically on tsunami hazards in Oregon coastal communities that are particularly vulnerable to tsunamis. References to online introductory and supporting documents are provided on the last page.
Relative earthquake hazard maps compare the expected violence of earthquake ground shaking and likely damage over a map area produced by a generic earthquake outside of the mapped region. Relative earthquake hazard maps are usually a combination of several different earthquake risks added together. For example, the Oregon Department of Geology and Mineral Industries (DOGAMI) constructed relative earthquake hazard maps for regions in Oregon by combining slope instability (landslide), amplification of ground shaking by weak near-surface geology, and liquefaction potential into one map.
Word format file on liquefaction containing a student worksheet.
Poster illustrates the violence of ground shaking expected for three kinds of earthquakes: (1) Cascadia subduction zone great earthquake; (2) “deep” earthquake within subducting Juan de Fuca Plate beneath Pacific Northwest (e.g. Nisqually 2001); and (3) local magnitude 7 earthquake on Portland Hills Fault.
Poster illustrates the violence of ground shaking expected for three kinds of earthquakes: (1) Cascadia subduction zone great earthquake; (2) “deep” earthquake within subducting Juan de Fuca Plate beneath Pacific Northwest (e.g. Nisqually 2001); and (3) local magnitude 7 earthquake on the Seattle Fault.