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II

Max Est. MMI

M3.4 earthquake · shaking intensity by town 16 km WSW of Toms Place, CA

Magnitude3.4
Depth7.3 km
Time 2026-07-30T15:34:57.120000Z UTC: 2026-07-30T15:34:57.120000Z
USGS ID nc75408617
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)
Mammoth Lakes
CA
760 519
West Bishop
CA
760 352
Dixon Lane-Meadow Creek
CA
760 294

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 +0.03 0.16 0.17
BSSA14 +0.02 0.16 0.16
CY14 +0.01 0.16 0.16
CB14 +0.02 0.17 0.17
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)
Lake Thomas A Edison (NC.MED) 0.0176 Weak(III) 0.388 Weak(III)
Convict Moraine #3 (NC.MCO) 0.0084 Weak(III) 0.084 Weak(II)
Casa Benchmark (NC.MCB) 0.0052 Weak(II) 0.100 Weak(II)
Lincoln Peak (NC.MLI) 0.0044 Weak(II) 0.086 Weak(II)
East Mammoth (NC.MEM) 0.0040 Weak(II) 0.062 Weak(II)
Long Valley Fire Station (NP.1576) 0.0039 Weak(II) 0.061 Weak(II)
Mammoth (CI.MLAC) 0.0037 Weak(II) 0.086 Weak(II)
Mammoth Lakes Knolls (NC.MMLB) 0.0036 Weak(II) 0.072 Weak(II)
Fire Station (NP.1679) 0.0022 Weak(II) 0.030 Not felt(I)
Dry Creek (NC.MDY) 0.0021 Weak(II) 0.054 Not felt(I)
Owens Valley Radio Observatory, Big Pine, CA (BK.OVRO) 0.0021 Weak(II) 0.059 Weak(II)
UCLA Research Station (NP.1589) 0.0021 Weak(II) 0.043 Not felt(I)
Cedar Grove (BK.CGRV) 0.0018 Weak(II) 0.034 Not felt(I)
Mammoth Mtn McCoy #2 (NC.MCY) 0.0018 Weak(II) 0.032 Not felt(I)
Highway Maintenance Yard (NP.2021) 0.0017 Weak(II) 0.037 Not felt(I)
White Mountain Estates (NC.MWE) 0.0015 Weak(II) 0.023 Not felt(I)
Patterson Mtn (BK.PATT) 0.0014 Weak(II) 0.026 Not felt(I)
Chidago Canyon (NC.MCC) 0.0013 Weak(II) 0.026 Not felt(I)
Bald Mountain (NC.MBM) 0.0011 Not felt(I) 0.029 Not felt(I)
Five Bridges (NC.MFBB) 0.0011 Not felt(I) 0.024 Not felt(I)
Lookout Mountain (NC.MLMB) 0.0010 Not felt(I) 0.035 Not felt(I)
Bear Mountain (NC.MBEB) 0.0009 Not felt(I) 0.016 Not felt(I)
Minaret Summit (NC.MINS) 0.0008 Not felt(I) 0.024 Not felt(I)
Petersen Ranch, Tollhouse, CA (BK.TOLH) 0.0006 Not felt(I) 0.009 Not felt(I)
Lindcove REC, Exeter, CA (BK.LIND) 0.0005 Not felt(I) 0.007 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
Mammoth Lakes
CA
Weak(II)
West Bishop
CA
Not felt(I)
Dixon Lane-Meadow Creek
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
Long Valley Fire Station (NP.1576) Weak(II)
Convict Moraine #3 (NC.MCO) Weak(II)
Mammoth (CI.MLAC) Weak(II)