Were Explosives the Source of the Seismic Signals Emitted from New York on September 11, 2001?

Journal of 9/11 Studies Volume 34, November 2012

Were Explosives the Source of the Seismic Signals Emitted from New

York on September 11, 2001?

By Dr. André Rousseau

1

We would like to thank Tod Fletcher, who provided

editorial assistance by revising an

earlier version of this article.

ABSTRACT

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 or a subaerial explosion. The magnitude of an aerial explosion is insufficient to provide seismic waves at 34 km.

The witnesses and video observation confirm our conclusions of subaerial explosions close to the times of aircraft impacts on WTC1 and WTC2, a strong

subterranean explosion closely correlated

with the WTC1 collapse,

and subaerial

explosions closely correlated

with the WTC2 and WTC7 collapses,

WTC7 not having

been hit by a plane. As a consequence, we draw the conclusion that the three buildings

were

demolished by a controlled process.

1

Dr. Rousseau is a

former researcher in

geophysics and geology at the National Center

for

Scientific Research

(CNRS) of France

and

a specialist in acoustic waves. He is also a

m

ember of Scientists for 9/11 Truth.

Journal of 9/11 Studies

Volume 34, November 2012

2

IN

TRODUCTION

When major shocks occur at the Earth'

s surface or at depth, waves of different types,

magnitudes and speeds may move out from the source location. Such waves can be

detected by seismometers located at recording stations and the data from the rec

ordings

can be analyzed to learn many details of the source events. Seismic signals were recorded

at stations in New York and four neighbouring states on September 11, 2001 during the

period when the North and South Towers (WTC1 and WTC2, respectively) wer

e struck

by airliners and collapsed, as well as during the collapse of Building 7 of the WTC,

which had not been hit by a plane.

Data from the Palisades, NY recording station, located 34 km north

-

north

-

east of

Manhattan, published by the Lamont

-

Doherty Ear

th Observatory of Columbia University

(LDEO), provide the most detailed seismic waveforms for analysis, particularly for the

determination of the locations (surface or underground) and timing of the events that

created the seismic waves.

Some authors have

been puzzled in their analysis of signals recorded for the events at the

World Trade Center, as the contradictions are significant. They are particularly intrigued

by the presence of seismic "

peaks"

before the collapses. (

S

ee MacQueen, 2009). This text

fo

cuses on the study of the seismic signals from Palisades. The new interpretation

presented here renders the assertions of the seismic analysis of the events at the WTC, as

presented by the government in the NIST and other reports, null and void. On the

co

ntrary, all the documented evidence points to explosions as the source of the recorded

seismic signals.

COMPOSITION OF DIFFERENT WAVEFORMS

Five waveforms will be analyzed below. They are attributed by the LDEO team to

specific causes, as follows:

1.

the sig

nals that, according to LDEO, match the moment when the planes hit

WTC1 and WTC2, respectively, shown in figures 1a and 1b;

2.

the signals that match the collapses of WTC1 and WTC2, respectively, shown in

figures 2a and 2b; and

3.

the signal that shows the col

lapse of WTC7, shown in Figure 2c.

The analysis presented here will question LDEO'

s identifications of the causes of the

waveforms.