Quick answer
Fault proximity is one input into earthquake risk, while shaking probability combines fault behavior, regional seismicity, attenuation, and site conditions. A nearby fault can matter, and modeled shaking tells how that hazard may be felt at a location. The fault question asks how distance and probability interact. Fault proximity can explain one hazard source, while probabilistic shaking accounts for more complete regional behavior. On EarthquakeScore, use the 0 to 10 score as a local-area signal, then read the supporting metrics, confidence, and source notes before moving to a property decision.
The practical workflow is simple: review this article, compare real local pages, read the methodology, and then check an address when a street-address view is needed. For related context, use How to read an earthquake risk score, Why soil conditions change earthquake damage risk, What 2% in 50 years means in seismic hazard.
How to interpret the signal
EarthquakeScore estimates earthquake risk at neighborhood-scale resolution, which is designed for comparing places more locally than broad county or city summaries. The model pays close attention to probabilistic shaking, fault proximity, site class, spectral acceleration, and recurrence assumptions. Those inputs give the score its shape, while the page-level metrics explain which part of the record is driving a particular location.
A careful reading avoids treating the headline score as the whole answer. The score is the entry point. The supporting metrics show severity, frequency, source coverage, and confidence. When those signals agree, the score is easier to compare across nearby places. When they diverge, the article and local page should be read together.
Local examples from current score pages
- ZIP 95537, Humboldt County, CA has a published score of 9.7. Use it as a concrete comparison point when reading nearby pages.
- ZIP 92254, Riverside County, CA has a published score of 9.7. Use it as a concrete comparison point when reading nearby pages.
- San Jose, CA has a published score of 9.6. Use it as a concrete comparison point when reading nearby pages.
These examples use existing score pages from the same site, with the same scoring scale and local page format. They give readers concrete comparison points across ZIPs, cities, counties, and states. A high score in one local page can sit beside lower or differently driven risk in another part of the same state, which is why the supporting metrics matter.
What official sources contribute
- USGS National Seismic Hazard Model is useful for probabilistic shaking hazard across the United States. A limitation to keep in mind: hazard values need site and building interpretation before they describe property damage.
- USGS Quaternary Fault and Fold Database is useful for mapped fault traces and fault activity context. A limitation to keep in mind: fault distance explains one part of hazard while shaking probability also reflects regional seismicity and soil response.
- USGS earthquake hazards program is useful for public earthquake hazard, monitoring, and science context. A limitation to keep in mind: program resources support hazard interpretation and still need building-specific vulnerability review.
Official sources provide the public record behind the analysis. The model turns those records into comparable local signals, while the source notes explain where confidence and interpretation matter. This source-aware reading is especially important for earthquake because public data can vary by reporting density, map update cycles, instrument coverage, or local documentation practice.
How to use confidence, scale, and timing
Earthquake risk combines regional seismic hazard with local ground conditions and building vulnerability. A score can summarize modeled exposure, but the decision usually depends on the question being asked. A buyer may care about shaking probability, liquefaction potential, hillside stability, and retrofit history. An owner may care about cripple walls, soft-story conditions, foundation anchoring, and local soil response. A planner may care about consistent comparison across ZIPs and counties. Read the scale first: ZIP, city, county, and state pages answer different questions. Then read the confidence language and source notes. Higher confidence usually means hazard maps, fault context, and local indicators point in the same direction. Lower confidence calls for closer review of site class, building age, and parcel-level engineering information.
Timing also matters. Seismic probabilities describe long-run likelihood across a time window, while damage depends on the shaking from a future event at a specific site. Long quiet periods can occur in active seismic regions. Align the metric with the decision before comparing locations.
How this connects to property decisions
A local score helps readers decide where to look more closely. Property-level review asks a narrower question: how does this specific building or parcel respond to the local hazard context? For earthquake, property factors include building age, structural system, retrofit status, foundation type, soft-story conditions, and soil class. These details can change vulnerability, expected damage, or the cost of mitigation.
Use the local score for screening, comparison, and research. Use the address check for the building and parcel context. That sequence creates a clearer audit trail: official source, EarthquakeScore methodology, local score page, and property-specific review.
Related reading and next steps
For more context, continue with How to read an earthquake risk score, Why soil conditions change earthquake damage risk, What 2% in 50 years means in seismic hazard. The articles library covers related questions in the same scoring system, so the terminology and examples stay consistent across the site.
Next, browse one of the local examples above, open the methodology, and check an address for a property-specific PerilScore. That path keeps the analysis grounded in source data, local scoring, and property context.