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Max Est. MMI

20 km WSW of Gerlach, Nevada

Magnitude4.1
Depth6.9 km
Time 2026-09-16T07:17:25.899000Z UTC: 2026-09-16T07:17:25.899000Z
USGS ID nn00924508
ShakeMap View USGS ↗

Engineering Ground Motion Parameters

GMPE predictions provide an independent check on the ShakeMap interpolated intensities above. ShakeMap relies on seismic station recordings; in areas with sparse station coverage — or for large teleseismic events and earthquakes outside dense West Coast networks — ShakeMap MMI can be inaccurate. A significant difference between ShakeMap and GMPE estimates is a signal that the ShakeMap result should be treated as preliminary. Also includes site Vs30 values and raw ground motion parameters (PGA/PGV).

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Est. Vs30 Values

Estimated shear-wave velocity in the upper 30 m used in GMPE calculations. Ref. column shows the 760 m/s rock-site reference for comparison.

Location Ref. (760 m/s) Est. Vs30 (m/s)
Janesville
CA
760 435
Johnstonville
CA
760 230
Susanville
CA
760 301

MMI vs Distance — Default Vs30 (760 m/s)

All methods using the 760 m/s rock-site reference. ShakeMap values are independent of Vs30.

MMI vs distance — default Vs30

MMI vs Distance — Est. Vs30

GMPEs use the Est. Vs30 values shown in the table above. ShakeMap values are independent of Vs30.

MMI vs distance — Est. Vs30

GMPE Residual — Observed − Predicted MMI

Signed residual at each seismic station. Positive values mean the GMPE underestimated shaking; negative values mean it overestimated. The dashed line at zero indicates perfect agreement.

GMPE residual plot

GMPE Predicted vs. Observed MMI at Seismic Stations

Each point is one seismic station. Points on the dashed 1:1 line indicate perfect agreement; above the line = GMPE underestimated shaking; below = overestimated.

GMPE predicted vs observed scatter

GMPE Performance — Station Observations

Statistics computed by comparing each GMPE's predicted MMI against ShakeMap observed MMI at seismic stations. Bias = mean(observed − predicted). Lower RMSE indicates better overall agreement with instrumental measurements.

GMPE Bias Sigma RMSE
ASK14 +0.09 0.24 0.25
BSSA14 +0.09 0.24 0.25
CY14 +0.09 0.24 0.25
CB14 +0.09 0.24 0.25
Bias > 0: GMPE underestimated shaking at stations. Bias < 0: GMPE overestimated shaking.

Peak Ground Motion — Seismic Station Observations

Recorded PGA and PGV at seismic stations, sorted by highest PGA. Top 25 stations shown. MMI (PGA) and MMI (PGV) are independent conversions via Worden et al. (2012) GMICE.

Station PGA (g) MMI (PGA) PGV (cm/s) MMI (PGV)
Pyramid Lake 2 (NN.PYM2) 0.0028 Not felt(I) 0.055 Not felt(I)
Fox Mountain, NV (NN.FOX) 0.0008 Not felt(I) 0.041 Not felt(I)
Winnemucca Valley, Nevada w84 (NN.WVA) 0.0008 Not felt(I) 0.025 Not felt(I)
Pah Rah Range, Nevada w84gm (NN.PAH) 0.0007 Not felt(I) 0.016 Not felt(I)
Manzanita Lookout (BK.MZTA) 0.0005 Not felt(I) 0.024 Not felt(I)
Washoe County DEM, Nevada (NN.WDEM) 0.0004 Not felt(I) 0.028 Not felt(I)
Shaffer Mountain (WR.SFM) 0.0003 Not felt(I) 0.016 Not felt(I)
Bishop Manogue Catholic High School, Reno, NV (NN.BMHS) 0.0003 Not felt(I) 0.016 Not felt(I)
Verdi Peak, California (NN.VPK) 0.0003 Not felt(I) 0.021 Not felt(I)
Sage Hen site 5, Independence Lake, CA (NN.SAG5) 0.0003 Not felt(I) 0.020 Not felt(I)
Diaz Spring, Lassen County (BK.DIAZ) 0.0002 Not felt(I) 0.016 Not felt(I)
Redfield Campus, S. Reno, Nevada (NN.REDF) 0.0002 Not felt(I) 0.008 Not felt(I)
Crater Lake (NC.LCL) 0.0002 Not felt(I) 0.012 Not felt(I)
Porcupine Ridge (BK.PORC) 0.0002 Not felt(I) 0.008 Not felt(I)
Beckwourth Peak (WR.BKW) 0.0002 Not felt(I) 0.014 Not felt(I)
Loyalton, CA digital upgrade (NN.LOYB) 0.0002 Not felt(I) 0.008 Not felt(I)
Ravendale, CA (BK.RAVE) 0.0002 Not felt(I) 0.013 Not felt(I)
Little Valley, Lassen County (BK.LITV) 0.0002 Not felt(I) 0.011 Not felt(I)
Swain Mt (BK.SWNM) 0.0001 Not felt(I) 0.008 Not felt(I)
Beckworth, California w84 (NN.BEK) 0.0001 Not felt(I) 0.003 Not felt(I)
Eagle Lake, Susanville, CA USA (BK.EAGL) 0.0001 Not felt(I) 0.015 Not felt(I)
Washoe Valley, Nevada;Laurence Kaplan Property (NN.WASH) 0.0001 Not felt(I) 0.005 Not felt(I)
Baker Forest (BK.BKFS) 0.0001 Not felt(I) 0.006 Not felt(I)
Dry Creek Basin Area (BK.DRYC) 0.0001 Not felt(I) 0.003 Not felt(I)
Butt Valley Reservoir (BK.BTVR) 0.0001 Not felt(I) 0.003 Not felt(I)
Source: USGS ShakeMap station recordings (view ShakeMap). PGA in g (fraction of gravitational acceleration); PGV in cm/s. The observed MMI shown on the map uses ShakeMap's reported instrumental intensity where available, or max(MMI from PGA, MMI from PGV) otherwise.

Ground Shaking Intensities — Interpolated ShakeMap MMI

3 sites
Location MMI Description
Janesville
CA
Not felt(I)
Johnstonville
CA
Not felt(I)
Susanville
CA
Not felt(I)

Seismic Station Observed MMI

MMI values are derived directly from observed ground motion measurements at seismic stations and are not spatially interpolated.

3 stations
Station MMI Description
Fox Mountain, NV (NN.FOX) Not felt(I)
Pyramid Lake 2 (NN.PYM2) Weak(II)
Ravendale, CA (BK.RAVE) Not felt(I)