World Trade Center Jet Impact Seismic Signals
NOTE: The various Disinformation operations always mix in real info to discredit it, and the seismic signals are a common target.
FEMA: "Although dramatic, these fireballs did not explode or generate a shock wave."
1. Why is the first seismic signal twice as long as the second?
2. Why was the 1993 2100MJ high explosive (HE) detonation two floors underground not detected seismically?
3. How does a jet impacting parallel with the ground between floors 94 and 98 with 2,358MJ of kinetic energy cause a larger seismic signal than a 3,150MJ HE detonated two floors underground?
4. Can a low order jet fuel explosion between floors 94 and 98 or between floors 78 and 84 cause the seismic signals?
A 1993 World Trade Center Truck Bomb truck bomb at the WTC in 1993 , in which approximately 0.5 tons of explosive were detonated, was not detected seismically, even at a station only 16 km away. ldeo.columbia.edu
Seismic signals from both impacts are characterized by relatively periodic motion and their spectra are above the noise only for frequencies from about 1.3 to 1.6 Hz. Those frequencies are more than 10 times the frequency of the lateral fundamental mode of each tower. ldeo.columbia.edu
Seismic signals associated even with high-speed impacts of the heaviest aircraft types are small, typically equivalent to those from magnitude 2 earthquakes or even smaller, which means they are generally detectable only within a few hundred kilometers of the crash site even by the most sensitive equipment under optimal conditions. http://www.ctbto.org/fileadmin/content/reference/outreach/spectrum_issues_singles/ctbto_spectrum_2/p1.pdf