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Interactive California Earthquake Hazard Zone Map

April 2, 2018

Wondering if you live near an earthquake fault? An avalanche area? A liquefaction zone?

Now you can find out from the State of California Department of Conservation.

I don’t think the research is complete. It doesn’t show the Northridge Fault (which broke in 1994) for example, and the liquefaction zone around that fault seems incomplete. Large areas, in fact, are color-coded white for “Areas not evaluated for liquefaction or landslides.” So just because you live on flat land with no nearby fault marked, don’t assume you’re free from danger.

But it’s a work-in-progress and interesting to look at. If a danger is indicated, it’s probably accurate. If no danger is indicated, you’re probably looking at an “Area not [yet] evaluated for liquefaction or landslides.”

The screen shot below is based on the address 1000 Wilshire Blvd., the small dark dot in lower left of picture. Green areas are liquefaction, yellow are fault zones, broken lines are approximately located faults. Right half of the screen is the legend, which disappears with a button click to leave a full-screen map. Map includes all of California.

Santa Monica Earthquake, Liquefaction & Avalanche areas (4/2/18 screenshot)

In 1994 we lived at 1533 11th St. in Santa Monica. The map does not indicate that this in a liquefaction or earthquake fault zone. Yet the 1994 Northridge quake gave us quite a shaking. All the dishes leaped from the cupboards, bookshelves collapsed and the TV set rolled freely across the floor. Sleep for that night had ended.

Brief instructions.
1. Go to the website
2. Click the button “Launch EQ Zapp” and wait a few minutes for it to fully load the map.
3. You can move the map around and zoom in/out with your mouse and mouse scroll wheel.
4. Enter an address into the box titled “Esri World Geocoder.” A drop down menu will probably appear to make the typing easier.
5. The map will zoom in and your desired location will be in the screen center. Click the “X” on the “Search Result” label to make it disappear. A dot will remain on the location.
6. Use your mouse and scroll wheel to move around and zoom in/out to see what’s around.
7. When colors appear (yellow, dark green-blue, aqua, peach, pink), click the legend (three horizontal bars in upper right corner). An explanation of all the colors and lines will appear.
8. Click the down arrows in upper right corner to shrink the legend.
9. Start all over by typing in a different address.

Live dangerously, but have fun, kids!
[Chuck Almdale]



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