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IV

Max Est. MMI

M4.4 earthquake · shaking intensity by town 6 km NW of Delta, B.C., MX

Magnitude4.4
Depth8.1 km
Time 2026-02-11T08:38:33.450000Z UTC: 2026-02-11T08:38:33.450000Z
USGS ID ci41395584
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)
Nuevo León
MX 		760 198
Delta
MX 		760 190
Michoacán de Ocampo
MX 		760 187

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 -0.20 0.37 0.42
BSSA14 -0.14 0.34 0.36
CY14 -0.10 0.32 0.34
CB14 -0.09 0.33 0.34
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)
CERRO PRIETO (BC.CPX) 0.1787 Strong(VI) 0.975 Weak(III)
Ejido Tlaxcala (BC.TL2X) 0.1323 Strong(VI) 0.667 Weak(III)
CA:El Centro;ECA11 McCabe Sch (NP.5058) 0.0159 Weak(III) 0.508 Weak(III)
Guadalupe Victoria (BC.GUVIX) 0.0127 Weak(III) 0.556 Weak(III)
El Centro (CI.ELO) 0.0117 Weak(III) 0.482 Weak(III)
Desert Research Extended Center (CI.DRE) 0.0102 Weak(III) 0.527 Weak(III)
UABC Campus Mexicali (BC.UABX) 0.0081 Weak(III) 0.462 Weak(III)
East Mesa (CI.EMS) 0.0079 Weak(III) 0.350 Weak(III)
Imperial (CI.IMP) 0.0058 Weak(III) 0.228 Weak(II)
Pescaderos la 14 (BC.PESCX) 0.0058 Weak(III) 0.292 Weak(III)
Fire Station (NP.5053) 0.0058 Weak(III) 0.215 Weak(II)
Bonds Corner, Omlin Residence (NP.5054) 0.0057 Weak(II) 0.259 Weak(II)
Ejido Aguascalientes (BC.AGSX) 0.0053 Weak(II) 0.163 Weak(II)
Riito (BC.RITX) 0.0039 Weak(II) 0.129 Weak(II)
Cook Ranch 2 (CI.COK2) 0.0031 Weak(II) 0.141 Weak(II)
Coachella (CI.COA) 0.0027 Weak(II) 0.172 Weak(II)
Signal Mtn (CI.SGL) 0.0026 Weak(II) 0.077 Weak(II)
Schaffner Ranch (CI.SNR) 0.0024 Weak(II) 0.130 Weak(II)
Midway Well (NP.5272) 0.0024 Weak(II) 0.211 Weak(II)
American Girl Mine (CI.AGM) 0.0020 Weak(II) 0.064 Weak(II)
Rancho Alamar- (BC.ALAMX) 0.0020 Weak(II) 0.049 Not felt(I)
Ocotillo Community Park (CI.OCP) 0.0019 Weak(II) 0.087 Weak(II)
El Centro Array 1, Borchard Ranches (NP.5056) 0.0019 Weak(II) 0.110 Weak(II)
San Luis Rio Colorado (BC.SLRCX) 0.0017 Weak(II) 0.070 Weak(II)
Ruthven (CI.RUN) 0.0015 Weak(II) 0.070 Weak(II)
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
Nuevo León
MX 		Light(IV)
Delta
MX 		Light(IV)
Michoacán de Ocampo
MX 		Light(IV)

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
CERRO PRIETO (BC.CPX) Weak(III)
Ejido Tlaxcala (BC.TL2X) Weak(III)
Ejido Aguascalientes (BC.AGSX) Weak(II)