Bulletin of the Seismological Society of America; February 2006; v. 96; no. 1;
p. 237-257; DOI: 10.1785/0120050052
© Seismological Society of America
Click on image to view larger version.
Figure 4. East–west components of CR-1 array in Millikan Library, recorded during
the M 6.1 Whittier Narrows earthquake 
= 19 km, velocity
time series. The top trace is from the basement, the second is from the sixth
floor, and the last two are from the roof. The last trace includes a sample of
how the fundamental frequency of the building is estimated, after the main
energy (seen from the basement trace) has passed.
