Earthquakes happen around the globe all the time because of the stresses and strains in the Earth’s crust resulting from the motions of the tectonic plates. Fortunately, most are too small to cause much damage. Yet, sometimes the stresses are large and when the rocks finally break, the energy release can be catastrophic to people living on or near active fault zones. Alaska is “blessed” with a subduction zone and several major transform fault systems that create more earthquakes by far than anywhere else in the US. This content page includes the resources you need to start building your case study for your chosen earthquake disaster! Start by watching the short YouTube videos below that give examples of devastation and the ensuing panic that can happen after an earthquake (in this example, from Christchurch, New Zealand), and some history from the 1964 earthquake that struck Alaska.
__________________________________________________________
Science Topics and Resources for Earthquake Hazards:
Week 1: Basic science – follow the steps below to learn the basics. Week 1 assignments are given in the Case Study 1 page
1) What causes earthquakes? Plate tectonics creates forces on the lithospheric plates that stress, deform, and eventually break the rocks. Read about elastic rebound theory and watch the animation below:
- Read about Reid’s Elastic Rebound Theory from the USGS Earthquake Hazards program.
- Elastic Rebound Animation (from IRIS – Incorporated Research Institutions in Seismology) Note – you can find many more elastic rebound videos on IRIS YouTube Channel
2) What are faults? Faults are cracks in the Earth’s crust along which the rocks on either side of the fault move. Read about the different types of faults described in a publication by the IRIS program. Then, watch the fault motion animations below, also provided by IRIS.
- Strike Slip Faults
- Normal Faults
- Reverse Faults
3) Learn all about earthquakes, seismic waves, the Richter magnitude scale, and how they are measured by reading the content from the Michigan Tech UPSeis website. Be sure to watch the animations linked in that source (some are repeated on this webpage), and you can also view them on the website by Larry Braile at Purdue University, who created them.
4) Watch the seismograph animations below:
- Horizontal Seismograph
- Vertical Seismograph
__________________________________________________________________________
Week 2: Earthquake hazards, monitoring, damage, and mitigation-follow the steps below to learn the basics. Week 2 assignments are given in the Case Study 1 page
1) Read about locating earthquakes, estimating magnitude, and epicenter on the UPSeis and USGS websites:
- Estimating location and magnitude
- Modified Mercalli Intensity Scale
- Use the Virtual Earthquake program to locate your own earthquakes and estimate magnitude
2) Read about how earthquakes cause building damage, and watch animations about ground properties and liquefaction:
- Earthquakes and building damage
- Shaking and liquefaction animation from IRIS
- Shaking, ground properties, and building effects animation from IRIS
3) Read all of the sections in Earthquake Hazards 101 from the USGS Earthquake Hazards program.
4) Play the Stop Disasters Game Earthquake Module. You are in charge of keeping people in a city safe during a destructive earthquake!
_________________________________________________________________________
Week 3 and Case Study Report – Assignment is given on the Case Study 1 and 2 pages. For Case Study 2, you are required to provide one additional paragraph comparing and contrasting your two case studies disasters.