Max Est. MMI
M3.9 earthquake · shaking intensity by town 6 km WNW of Wauna, Washington
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) |
|---|---|---|
|
Wauna
WA |
760 | 555 |
|
Key Center
WA |
760 | 464 |
|
Burley
WA |
760 | 373 |
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 | -0.07 | 0.51 | 0.51 |
| BSSA14 | +0.11 | 0.48 | 0.49 |
| CY14 | -0.47 | 0.57 | 0.74 |
| CB14 | -0.20 | 0.52 | 0.55 |
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) |
|---|---|---|---|---|
| Seahawks 6, Seattle, WA, USA (UW.HWK6) | 0.0118 | Weak(III) | 0.699 | Weak(III) |
| South Pierce Fire and Rescue, Eatonville, WA, USA (UW.SPFR) | 0.0104 | Weak(III) | 0.173 | Weak(II) |
| Kent Elementary, WA, USA (UW.KNEL) | 0.0097 | Weak(III) | 0.506 | Weak(III) |
| Bethel School District OSC, Spanaway, WA, USA (UW.BRAV) | 0.0091 | Weak(III) | 0.225 | Weak(II) |
| Vashon High School, Vashon Island, WA, USA (UW.VVHS) | 0.0090 | Weak(III) | 0.259 | Weak(II) |
| McLane Black Lake Fire Department, Olympia, WA, USA (UW.MCLN) | 0.0086 | Weak(III) | 0.224 | Weak(II) |
| Evergreen Elementary, Lakebay, WA, USA (UW.KEYP) | 0.0077 | Weak(III) | 0.269 | Weak(II) |
| Komachin High School, Lacey, WA, USA (UW.KWOLF) | 0.0075 | Weak(III) | 0.227 | Weak(II) |
| Tumwater School District #33, Tumwater, WA, USA (UW.TUMW) | 0.0075 | Weak(III) | 0.195 | Weak(II) |
| Purdy Elementary School, Lakebay, WA, USA (UW.PURDY) | 0.0075 | Weak(III) | 0.189 | Weak(II) |
| Lacey Fire Station 36, Lacey, WA, USA (UW.TORK) | 0.0072 | Weak(III) | 0.230 | Weak(II) |
| Lakebay, WA, USA (UW.TKEY) | 0.0071 | Weak(III) | 0.299 | Weak(III) |
| West Thurston Regional Fire Authority, Olympia, WA, USA (UW.TRFA) | 0.0069 | Weak(III) | 0.244 | Weak(II) |
| Lake Cushman Maintenance Company, Lake Cushman, WA, USA (UW.LCMC) | 0.0068 | Weak(III) | 0.205 | Weak(II) |
| City of Normandy Park, Normandy Park, WA, USA (UW.NMDY) | 0.0063 | Weak(III) | 0.361 | Weak(III) |
| South Kitsap Fire Station #11, Port Orchard, WA, USA (UW.SKIT) | 0.0062 | Weak(III) | 0.101 | Weak(II) |
| Celestial Japanese Maples, Gig Harbor, WA, USA (UW.MAPLE) | 0.0062 | Weak(III) | 0.183 | Weak(II) |
| Pierce County Sheriff Department Training CTR, Roy, WA, USA (UW.PCFR) | 0.0059 | Weak(III) | 0.169 | Weak(II) |
| Green Mountain, WA, USA (UW.GNW) | 0.0059 | Weak(III) | 0.044 | Not felt(I) |
| Dosewallips, Brinnon, WA, USA (UW.DOSE) | 0.0059 | Weak(III) | 0.130 | Weak(II) |
| Seahawks 2, Seattle, WA, USA (UW.HWK2) | 0.0053 | Weak(II) | 0.334 | Weak(III) |
| Sun Top (CC.SUNT) | 0.0052 | Weak(II) | 0.216 | Weak(II) |
| Tacoma, WA, USA (UW.MAC) | 0.0051 | Weak(II) | 0.183 | Weak(II) |
| Mount Baker Middle School, Auburn, WA USA (UW.BLDG) | 0.0050 | Weak(II) | 0.223 | Weak(II) |
| DuPont City Hall, DuPont, WA, US (UW.DUPO) | 0.0048 | Weak(II) | 0.197 | Weak(II) |
Ground Shaking Intensities: Interpolated ShakeMap MMI
3 sites| Location | MMI Description |
|---|---|
|
Wauna
WA |
Weak(II) |
|
Key Center
WA |
Weak(II) |
|
Burley
WA |
Weak(II) |
Seismic Station Observed MMI
MMI values are derived directly from observed ground motion measurements at seismic stations and are not spatially interpolated.