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Quake Risk for Earthen Buildings

Check before you build.

Scientists update risk maps when they get more information. Most recent is best. If you can't find accurate local maps, check out our estimated risk maps. Our measurement units match those used in New Zealand for their unique standards-based earthen building code.

Download 170 kb map pdfs below:

Seismic risk apps

Other online resources

If developed world building officials say quake risk doesn't require engineering for unreinforced masonry, earthen buildings may have low risk. But many government web tools can give precise data for an address. Look for Ss (short period or 0.2 second) pga values that apply to low-rise buildings.
GEM has a global seismic hazard map online (excerpts shown below) and Preventionweb has more local information. The GEM maps at 10% probability in 50 years differ:
BSI maps: 2% in 50 years      GEM maps: 10% in 50 years
Low risk                                0.25- 0.6 g                          0.05- 0.12 g
Medium- high risk              0.6- 1.7 g                            0.12- 0.34 g

Australia

Australia updated their map in 2018. They may not have a web tool, but their seismic hazard map is online.

Europe

The EFHR's online hazard data access allows you to zoom in on a map. Type latitude and longitude, select SA 0.2, POE 2% in 50, rock, arithmetic. Turn on layers for roads. 

United States

Use ATC's hazards by location app. After the address, choose seismic, and specify risk category II (unless it's a church or school) and site class D (hard ground unless it's very soft or bedrock). Look for the Ss number.

Canada

Use Natural Resources Canada's seismic hazard values tool. Type your latitude and longitude in, then click submit. Scroll down to see the top table (2%/50 yrs), then click on the 3rd column to the right (Sa 0.2).