1987 Whittier Narrows-01, Norwalk

Plots of original ground motion, extracted pulse, and residual ground motion:

Map of epicenter, rupture extent and station location:

Ground motion information:

NGA Record Sequence Number 668

Magnitude = 6
Closest Distance = 20.4 km
Hypocentral Distance = 20.92 km
Vs30 = 306 m/s
Mechanism = Reverse-oblique

T_p = 0.9 s
PGV = 28 cm/s

Orientation of strongest pulse, relative to north = 162 degrees
Orientation of strongest pulse, relative to fault parallel = 62 degrees
Pulse in fault normal direction = 0
Pulse due to directivity = 0

Comments:

Poor directivity geometry, large distance given the amount of rupture between the fault and site

Directivity parameters:

X = 0.36
s = 3.59 km
θ = 76.1

Y = 0.03
d = 0.19 km
φ = 15.1

IDP = 0.05
Rowshandel parameter = -0.16

Notes:

These results were computed November 1st, 2012
These results are based on the June 2012 version of the NGA West 2 database
If you have any observations, comments or requests regarding this data, please e-mail Jack Baker and Shrey Shahi