abstract

• We show how the concept of doorway states carries beyond its typical applications and usual concepts. The scale on which it may occur is increased to large classical wave systems. Specifically we analyze the seismic response of sedimentary basins covered by water-logged clays, a rather common situation for urban sites. A model is introduced in which the doorway state is a plane wave propagating in the interface between the sediments and the clay. This wave is produced by the coupling of a Rayleigh and an evanescent SP-wave. This in turn leads to a strong resonant response in the soft clays near the surface of the basin. Our model calculations are compared with measurements during Mexico City earthquakes, showing quite good agreement. This not only provides a transparent explanation of catastrophic resonant seismic response in certain basins but at the same time constitutes up to this date the largest-scale example of the doorway state mechanism in wave scattering. Furthermore the doorway state itself has interesting and rather unusual characteristics. Copyright © 2011 EPLA.

authors

• Flores J.
• Franco Villafañe John Alexander
• Mateos J.L.
• Méndez-Sánchez R.A.
• Novaro O.
• Seligman T.H.

publication date

• 2011-01-01

published in

• EPL  Journal

Digital Object Identifier (DOI)

• 10.1209/0295-5075/94/30005

start page

end page

volume

• 94

issue

• 3