Part 4—Analyze Tsunami Risk for Coastal Oregon

Step 1 – Launch AEJEE and Adjust Layers

1. Launch AEJEE by double-clicking its icon on your desktop or by clicking its icon in the dock (Mac) or Launch Bar (Win).
2. Choose File > Open..., and navigate to the file, TsunamiRunup_Part3.axl, that you saved at the end of Part 3. Select it and then click Open.




3. Move the new layer, OR Coast contour 5m, in-between the Tsunami Inundation Area and Plate Boundary Types layers.
   Show me how to move a layer
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   1. To move a layer, single click on it in the Table of Contents, then drag it to a new location in the list. You will see a gray line indicating where the layer will end up. Release the layer and it will be in its new location.
      
      
   2. In this image the layer has been moved and the Tsunami Inundation Area layer turned on.
      
      
   Show me what to do if I accidentally discard a layer
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   At this point, it is easiest just to quit AEJEE and NOT save any changes. Then, re-launch the program and re-open the project file. When the project opens again, all the data will be there.

Step 2 – Turn on the Oregon Tsunami Events and Investigate the Relationship between Coastlines and Tsunamis

In this step, you will investigate whether tsunami run-up events occur more frequently on steeply-sloped or more gradual, beach-like, shorelines.

1. Turn on the Tsunami RunUp layer and investigate the relationship between coastal topography and tsunami events. Note: you may decide that you need to change the color of the tsunami run-up events for more contrast; magenta is a good choice.
Show me how to edit the properties
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Right click on the layer's name, use the drop-down menu to choose Properties.... In the Properties window change the color to magenta.


2. Use the Pan and Zoom / tools to move around the map. When you are done exploring, you should be able to describe the types of shorelines that seem more tsunami-prone.
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   There appear to be more tsunami occurrences on gradual shorelines.
3. Zoom back to the extent of the state of Oregon.
   Note: A quick way to accomplish this is to turn on and make active the Oregon Border layer and click the Zoom to Active Layer layer button.

Step 3 – Query the Oregon Coast Contour Layer to Locate Populated Areas that are at Risk

1. Turn on and make active the Oregon Place Names layer.
2. Click the Query Builder button .
3. In the Query Builder window, find the places whose designation (DESIG) is populated place (ppl). You can either make selections in the Select a field: and Values: lists or manually entering this query statement: (DESIG = 'ppl' ) in the query field. Click Execute. Note: Since there are over 100 results, it is not necessary to display the query results in the query box.
   Show me the query builder window
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Take a moment to observe the pattern of population in Oregon, shown as yellow dots on this map. Are there more populated areas by the coast or inland? What other questions do these population patterns raise?
Show me Oregon populated places
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4. Next, locate the areas of the Oregon coast that are at a low elevation level, and therefore the most tsunami-prone.
   • Turn on and make active the OR Coast contour 5m layer.
   • Click the Query Builder button .
   • Select a field: "elevation" whose values are greater than or equal to 0, and less than or equal to 25 by manually typing this equation into the query field (elevation >= 0 and elevation
   • Click Execute.
     Show me query builder window
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5. Once the selection is complete, return to the map. You will need to zoom, pan, and adjust layers to investigate this selection more carefully.
   Show me the results
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   The map below has been zoomed to the Northwestern corner of Oregon.
   
   
6. Use the Identify tool to learn the height above sea level of each of the selected contour lines. This tool is a quick way to gather information from an Active layer. Make the Oregon Coast contour 5m layer active, then select the Identify tool and click on the contour lines that are highlighted in yellow. The line will flash briefly and an Identify Results window will open.
Show me the results window
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7. In general, many beachfront towns seem vulnerable to a tsunami in this range (0-25 meters).
8. Turn off the Oregon Place Names layer.

Step 4 – Turn on the Tsunami Inundation Line Layer and Compare it with the 20-meter Tsunami Contour

1. Turn on the Tsunami Inundation Area layer and compare it with the contour lines that you highlighted in the last step.
2. How do the contour lines compare to the Tsunami Inundation Area?
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   They are pretty similar in most areas. The Tsunami Inundation Area is a more involved calculation that takes into account bathymetric contours and other variables. It seems to follow the 20-meter contour.
3. Turn off the OR Coast Contour 5m and Tsunami Inundation Area layers.

Step 5 – Locate the Town of Seaside, Oregon and use the Query Builder to find Tillamook Head

Recall that a large tsunami devastated the nearby town of Cannon Beach in March 1964. Seaside is the focus of our Case Study. Both of these towns are located near Tillamook Head. According to scientific research, one of the reasons that Seaside is at high risk of tsunami inundation is due to Tillamook Head, a large rock outcropping located south of the city. In the event of a tsunami, waves would pile up against this large outcrop concentrating their energy on Seaside.

1. Begin by turning on the Seaside Schools layer to locate the town of Seaside. Zoom into Northwest Oregon. Hint: it is easier to see the town if you turn off the OR Coast Contour 5m layer.
   Show me where Seaside is located
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   The town of Seaside is in northwest Oregon, near the mouth of the Columbia River. The schools are a pair of green dots in the center of the map below.
   
   
   
   
Where exactly is Tillamook Head? Use the Query Builder to locate this topographic feature along the Oregon coast.


2. Turn on and make active the Oregon Place Names layer. This layer contains names and locations of over 41,000 features in Oregon. By querying this dataset, you can find both natural and man-made locations. (Hint when querying: be patient, as this is a large dataset for AEJEE to handle.)
   
3. Begin by changing the symbol of the Oregon Place Names layer to green squares in the Properties of the layer.
4. In the Query Builder window type in the query statement: (NAME = 'Tillamook Head') and click Execute. AEJEE will search the database and locate the feature.
   Show me the query builder window
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   Close the query builder window to see Tillamook Head displayed on the map. Zoom in to the area of Tillamook Head and Seaside. Turn the OR Coast contour 5m layer on again. Seaside Schools, Tsunami Run-up Events, and Oregon Coast Contour 5m are displayed on the map. Notice that there have been several tsunami run-up events in this area.
   
   Note: The map below has been zoomed in and some layers have been turned off to simplify the map. To turn off the selections that you made earlier, select the OR Coast contour 5m layer and click the Clear all Selections button.
   
   
   

Step 6 – Save your Project and Quit AEJEE

1. Save your project with a new name, such as "Tsunami_runup_Part4".
2. Quit AEJEE.