Earthquakes and Ground Motions - Earthquake Engineering for Structural Design - page 285

-Accordingly, the number of important cycles is larger than for crustal
earthquakes, an observation involving special requirements for structures in the
areas affected by this earthquake type.
-Contrary to the crustal earthquakes, where the seismic-radiated energy is
dominated by surfaces waves (L and R), for the deep earthquakes the radiated
energy is mainly produced by the body waves (P and S).
-Due to the fact that the velocities are strongly attenuated by the large distance
of the source-site, they have no great influence on the characteristics of ground
motions, contrary to the great role they have for the crustal events. So, the
accelerations remain the most important characteristic for this kind of ground
motions.
-The local soil conditions may have a leader role in the pattern of these ground
motions. The bad soil conditions, as in the Eastern part of Bucharest, influenced
the recorded accelerations, introducing a long time vibration pulse.
-By comparing the North and South American earthquakes, Saragoni et al
(2004) show that the intraslab earthquakes are more damaging than the crustal
ones. The same conclusion results for Europe, if the crustal earthquakes from
Western and Central zones are compared with the intraslab Vrancea (Romania)
earthquakes.

7.8 REFERENCES

Aagaard, B.T. (2000): Finite-element simulation of earthquakes. Ph. D. Thesis,
California Institute of Technology, Pasadena, California
Aagaard, B.T. (2003): High quality earthquake animations, US Geological
Survey, Pasadena, California
http://pasadena.wr.usgs.gov/office/baagaard/research/animations/animations.html
Aagaard, B.T., Hall, J.F., Heaton, T.H. (2000): Simulation of near-source
ground motions with dynamic failure. ASCE Structure Congress, Philadelphia,
May 2000
Aagaard, B.T., Hall, J.F., Heaton, T.H. (2000): Sensitivity study near-source
ground motion. 12

th

World Conference on Earthquake Engineering, Auckland,
Aagaard, B.T., Hall, J.F., Heaton, T.H. (2001a): Characterization of near-source
ground motions with earthquake simulations. Earthquake Spectra, Vol. 17, No. 2,
177-207
Aagaard, B.,T., Heaton T.H., Hall, J.F. (2001b): Dynamic earthquake ruptures
in the presence of lithostatic normal stresses: Implications for friction models and
heat production. Bulletin of Seismological Society of America, Vol. 91, No. 6,
1761-195
Aagaard, B.T., Hall, J.F., Heaton, T.H. (2001c): Effect of fault dip and slip rake
on ground motions: Why Chi-Chi was a relatively mild M7.6 earthquake. Pacific
Earthquake Engineering Research Center, University of California, Berkeley
Report. (See also Bulletin of Seismological Society of America, Vol. 94, No. 1,
155-170)