Washington’s Blog 
Dec 2, 2012
André Rousseau is a Doctor of Geophysics and Geology, a former researcher in the French National Center of Scientific Research (CNRS), who has published 50 papers on the relationships between the characteristics of progressive mechanical waves and geology.
Dr. Rousseau is an expert on measurement of acoustic waves.
Rousseau says that the seismic waves measured on September 11th proves that the 3 buildings were brought down by controlled demolition. Specifically, in a new scientific article published by the Journal of 9/11 Studies , Rosseau writes:
The seismic signals propagating from New York on September 11, 2001, recorded at Palisades (34 km) and published by the Lamont-Doherty Earth Observatory of Columbia University (LDEO), have here been subjected to a new critical study concerning their sources. The aim of this paper is to demonstrate that the nature of the waves, their velocities, frequencies, and magnitudes invalidate the official explanations which imply as sources the percussion of the twin towers by planes and the collapses of the three buildings, WTC1, WTC2 and WTC7.
First of all, we show the contradictions in the official explanation between the seismic data and the timing of the events. Then we point out that it is strange that identical events (percussions of identical towers on the one hand, and collapses of identical towers on the other hand) at the same location would have generated seismic sources of different magnitudes. We demonstrate that only strong explosives could be the cause of such seismic waves, in accordance with the observed low frequencies. According to the nature of the recorded waves (body and surface waves), we can propose a location of each explosive source. According to the presence of shear waves or the presence of Rayleigh waves only, we hypothesize a subterranean … explosion.
Near the times of the planes’ impacts into the Twin Towers and during their collapses, as well as during the collapse of WTC7, seismic waves were generated. To the degree that (1) seismic waves are created only by brief impulses and (2) low frequencies are associated with energy of a magnitude that is comparable to a seismic event, the waves recorded at Palisades and analyzed by LDEO undeniably have an explosive origin.Even if the planes’ impacts and the fall of the debris from the Towers onto the ground could have generated seismic waves, their magnitude would have been insufficient to be recorded 34 km away and should have been very similar in the two cases to one another.
As we have shown, they were not.
We can only conclude that the wave sources were independently
detonated explosives ….
Controlled demolition of the three towers, suggested by the visual and audio witness testimony as well as by observations of video recordings of their collapses, is thus confirmed and demonstrated by analysis of the seismic waves emitted near the time of the plane impacts and at the moments of the collapses.
This seismic analysis is just one of multiple lines of scientific evidence implying that 3 buildings were brought down by controlled demolition: