Utah Home Hazard Map

Check a spot against mapped faults, liquefaction, landslides and recorded earthquakes before you buy or build.

Data: Utah Geological Survey, USGS, UGRC
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Find a place

Or click anywhere on the map to check that spot.

Site check

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Map layers
moved in last 15,000 yrlast 130,000 yrolder or undated
Where the state recommends a fault study before building.
very lowlowmoderatehighvery high
Detailed study areas plus the 1990s Wasatch Front regional maps. No color means not studied.
active or historicaldormant or undetermined
historical movementprehistoric or undated
M2.5M4M5.5+
Adds the four ratings together for every 1 km square, 0 to 12.
0–12–34–56–78 or more
How the ratings work
  • Faults. High inside a surface-fault-rupture study zone or within 150 m (500 ft) of a mapped trace. Elevated within 1 km, some within 5 km. Faults with no movement in the last 130,000 years count one step lower.
  • Liquefaction. The mapped class at the spot: high and very high rate High, moderate rates Elevated, low rates Some. A detailed study wins over the older regional map where both exist, and a range such as “moderate to high” counts as its upper end.
  • Landslides. High inside a mapped landslide, elevated within 300 m, some within 1 km.
  • Earthquakes. Counts recorded M2.5+ events within 25 km (15.5 mi) since 1990. High with 40 or more, or any M5+. Elevated with 15 or more, or any M4+. Some with 4 or more.

The screening index adds the four ratings. Unmapped liquefaction adds nothing, so a low index in an unmapped area tells you less.

What this map cannot tell you

This is a first screen for comparing areas. It does not replace a site-specific geotechnical study, and the Utah Geological Survey says its hazard maps should not be used that way.

  • Blank does not mean safe. Liquefaction is mapped for the Wasatch Front valleys, Tooele Valley, Cache Valley and a few study areas such as St. George and Zion. Detailed landslide mapping covers only parts of the state. Everywhere else is unstudied.
  • Strong shaking reaches far beyond the fault that causes it. A Wasatch fault earthquake would shake every valley along the Wasatch Front, whatever the distance rating says here.
  • Recorded earthquakes show where the ground has been active since 1990. Coal-mining areas in Carbon and Emery counties include mining-related events.
  • Flooding, debris flows, rockfall, radon, problem soils and wildfire are not included.
  • Shapes are simplified for the web by roughly 10 to 30 m. Do not read them to the lot line.
Sources
  • Utah Geological Survey: Quaternary Fault and Fold Database; Utah Geologic Hazards database (liquefaction susceptibility, surface-fault-rupture special study zones, landslide inventory, legacy landslide compilation); Wasatch Front liquefaction potential maps (Contract Reports 94-1 to 94-5 and Special Study 96, 1994–1999). Utah Geologic Hazards Portal
  • USGS earthquake catalog (ComCat), M2.5+ since 1990. Search the catalog
  • Utah Geospatial Resource Center: county and municipal boundaries, lakes, highways.