Point TT-7: Why Did the Twin Towers Collapse? The Seismic Evidence
[1] The 9/11 Commission Report also cited the LDEO analysis,
[2] although it did not confirm LDEO’s analysis of plane-impact times, basing its own conclusions on ground radar data instead of seismic wave data.
But independent analyses have disputed LDEO’s conclusions and thereby the conclusions reached by FEMA and NIST. These independent analyses dispute even more the conclusions of the 9/11 Commission.
[3] The magnitudes of the airplane impact shocks at WTC 2 and WTC 1, respectively, were 0.7 and 0.9. The collapse of WTC 2 caused a shock of magnitude 2.1; the collapse of WTC 1 caused a shock of magnitude 2.3.
[4] The signals were used to determine accurately when the plane impacts and collapses occurred.
[5]
The Best Evidence
The results of independent research conflict with the conclusions by LDEO (Lamont Doherty-Earth Observatory) that the waves were caused by airplane impacts and resulting building collapses.
In 2006, engineers Craig Furlong and Gordon Ross showed that the plane impacts could not have caused the seismic signals attributed to them by LDEO, because they originated several seconds before the 9/11 Commission’s radar-based times of impact.
The seismic events, therefore, must have resulted from causes of a different type. The best (and probably only plausible) candidate for these causes would seemingly be explosions in the basements of the Twin Towers, for which there is abundant physical and testimonial evidence.