Geology · Glossary

Liquefaction

Updated 2026-07-18

Liquefaction is the earthquake-induced loss of strength in loose, saturated granular soil. California Seismic Hazard Zone maps identify areas where liquefaction investigation may be required, but mapped status is not a parcel-specific conclusion.

What it means

Shaking can increase pore-water pressure so soil temporarily behaves more like a fluid, causing settlement, lateral spreading, or bearing failure.

Why it matters for land decisions

Potential liquefaction can affect foundations, utilities, grading, project cost, and permit studies.

  • Check CGS regulatory maps.
  • Use a site-specific geotechnical investigation.

People also ask

Does a liquefaction zone mean liquefaction will occur?

No. It identifies potential conditions warranting investigation, not certainty at every location.

Can engineering mitigate liquefaction?

Often risks can be reduced through foundation, ground-improvement, drainage, or site-design measures based on geotechnical analysis.

Official sources

Related terms

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