Max Est. MMI
9 km WSW of South Lake Tahoe, CA
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).
Show ▼
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).
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) |
|---|---|---|
|
South Lake Tahoe
CA |
760 | 305 |
|
Kingsbury
NV |
760 | 662 |
|
Tahoma
CA |
760 | 394 |
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 — Est. Vs30
GMPEs use the Est. Vs30 values shown in the table above. ShakeMap values are independent of 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 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 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 | +0.02 | 0.10 | 0.10 |
| BSSA14 | +0.02 | 0.10 | 0.10 |
| CY14 | +0.02 | 0.10 | 0.10 |
| CB14 | +0.02 | 0.10 | 0.10 |
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) |
|---|---|---|---|---|
| Weber Reservoir, near Camino (BK.WEBR) | 0.0028 | Not felt(I) | 0.044 | Not felt(I) |
| Blue Mountain (BK.BLUE) | 0.0016 | Not felt(I) | 0.026 | Not felt(I) |
| Weller Cave, Western Cave Conservancy, Sutter Creek, CA (BK.WELL) | 0.0014 | Not felt(I) | 0.030 | Not felt(I) |
| Signal Peak, Yuba Pass, CA (BK.YUBA) | 0.0012 | Not felt(I) | 0.013 | Not felt(I) |
| Dodge Ridge (BK.DRDG) | 0.0007 | Not felt(I) | 0.009 | Not felt(I) |
| Donner Summit, California (NN.DON) | 0.0005 | Not felt(I) | 0.006 | Not felt(I) |
| Redfield Campus, S. Reno, Nevada (NN.REDF) | 0.0005 | Not felt(I) | 0.011 | Not felt(I) |
| Copperopolis #3 (NC.MCUC) | 0.0004 | Not felt(I) | 0.006 | Not felt(I) |
| Montezuma Slough (WR.MOFF) | 0.0003 | Not felt(I) | — | — |
| Farmington Tower (NC.MFA) | 0.0003 | Not felt(I) | 0.009 | Not felt(I) |
| Antelope Valley (NC.MAV) | 0.0003 | Not felt(I) | 0.008 | Not felt(I) |
| Lincoln Peak (NC.MLI) | 0.0003 | Not felt(I) | 0.007 | Not felt(I) |
| Bloomer Hill #3 (NC.OBHB) | 0.0002 | Not felt(I) | 0.008 | Not felt(I) |
| Holt Union Elementary School (WR.HLT) | 0.0002 | Not felt(I) | 0.008 | Not felt(I) |
| Turlock Lake (NC.MTL) | 0.0002 | Not felt(I) | 0.007 | Not felt(I) |
| Sutter Buttes, CA, USA (BK.SUTB) | 0.0002 | Not felt(I) | 0.006 | Not felt(I) |
| Sherman Island (NP.SIA) | 0.0002 | Not felt(I) | 0.010 | Not felt(I) |
| Staten Island Levee Array (WR.STNI) | 0.0002 | Not felt(I) | 0.010 | Not felt(I) |
| Clifton Court Forebay South (WR.CLFS) | 0.0002 | Not felt(I) | 0.012 | Not felt(I) |
| New Hogan Dam (NC.MNHB) | 0.0002 | Not felt(I) | 0.007 | Not felt(I) |
| Miami Mountain, Sierra National Forest, Mariposa County (BK.MMI) | 0.0002 | Not felt(I) | 0.004 | Not felt(I) |
| Twitchell Island Reclamation, Rio Vista, CA (BK.TWIT) | 0.0002 | Not felt(I) | 0.015 | Not felt(I) |
| Forest Hills Divide #2 (NC.AFD) | 0.0002 | Not felt(I) | 0.006 | Not felt(I) |
| Lake Thomas A Edison (NC.MED) | 0.0002 | Not felt(I) | 0.005 | Not felt(I) |
| Sierra Foothills REC, Browns Valley, CA (BK.SFRE) | 0.0002 | Not felt(I) | 0.004 | Not felt(I) |
Ground Shaking Intensities — Interpolated ShakeMap MMI
3 sites| Location | MMI Description |
|---|---|
|
South Lake Tahoe
CA |
Weak(III) |
|
Kingsbury
NV |
Weak(II) |
|
Tahoma
CA |
Weak(II) |
Seismic Station Observed MMI
MMI values are derived directly from observed ground motion measurements at seismic stations and are not spatially interpolated.
| Station | MMI Description |
|---|---|
| Donner Summit, California (NN.DON) | Not felt(I) |
| Weber Reservoir, near Camino (BK.WEBR) | Weak(II) |
| Antelope Valley (NC.MAV) | Not felt(I) |