Strongest estimated shaking: SEVERE at Napa — MMI VIII, 9.4 km from epicenter

Modified Mercalli Intensity Scale

The 2014 South Napa, California Earthquake

Max Est. MMI	VIII Severe at Napa
Magnitude	M6.0
Local Time	3:20 AM PT, August 24, 2014
UTC	10:20:44, August 24, 2014
Depth	11 km
Epicenter	38.2152°N, -122.3123°
Event ID	nc72282711

● Official Sources

● Nearby Cities (ShakeMap MMI)

Shaking at the closest named locations in the Intensity Lab gazetteer:

Location	Region	Dist (km)	Est. Vs30	MMI
American Canyon	CA	6.3	760 m/s Default (760 m/s)	VI Strong
Napa	CA	9.4	760 m/s Default (760 m/s)	VIII Severe
Vallejo	CA	13.3	760 m/s Default (760 m/s)	VI Strong
Green Valley	CA	13.8	760 m/s Default (760 m/s)	V Moderate
Sonoma	CA	15.3	760 m/s Default (760 m/s)	VI Strong
Temelec	CA	16.8	760 m/s Default (760 m/s)	V Moderate
El Verano	CA	18.1	760 m/s Default (760 m/s)	V Moderate
Boyes Hot Springs	CA	18.4	760 m/s Default (760 m/s)	V Moderate
Fetters Hot Springs-Agua Caliente	CA	19.3	760 m/s Default (760 m/s)	V Moderate
Agua Caliente	CA	19.5	760 m/s Default (760 m/s)	V Moderate
Crockett	CA	20.1	760 m/s Default (760 m/s)	VI Strong
Rodeo	CA	20.6	760 m/s Default (760 m/s)	V Moderate
Black Point-Green Point	CA	20.8	760 m/s Default (760 m/s)	V Moderate
Yountville	CA	21.2	760 m/s Default (760 m/s)	V Moderate
Hercules	CA	22.1	760 m/s Default (760 m/s)	V Moderate

● MMI vs Distance

NGA-West2 GMPE predictions (colored lines) vs. ShakeMap interpolated MMI (gray dots) at all gazetteer sites. Shown here with a uniform 760 m/s rock-site reference for comparison; actual GMPE calculations use site-specific Est. Vs30 values shown in the table above.

Plot lines: ASK14, BSSA14, CY14, CB14 (NGA-West2 GMPEs). Dots: ShakeMap interpolated MMI at gazetteer sites.