Does Seismic Evidence Imply Controlled Demolition on 9/11

It's admittedly hard to know what happened in the brief instant as the plane blasted itself into the building spilling/spraying and flooding the fuel which could ignite from arcing /shorted electrical risers and exploded possibly/ probably. There was a freight car (55) shaft in the center of the core which went from the sub basement to the top mech floors... and this would be the likely path of fuel reaching down as low as the sub basement. I don't know where that car was at the time and it's impact of the fuel going down at whatever speed in the shaft.

Is it unreasonable to assume that fuel did pour down the shaft of car 55?
 
Jeffrey, I know that many elevator cars didn't go all the way from bottom to top, but that doesn't mean the shafts didn't! Elevators were stacked, right?
I think there's a chance of a car that's cut loose falling through the bottom of its designed range and into the basement, drawing behind it a fuel-air mix.
 
Jeffrey, I know that many elevator cars didn't go all the way from bottom to top, but that doesn't mean the shafts didn't! Elevators were stacked, right?
I think there's a chance of a car that's cut loose falling through the bottom of its designed range and into the basement, drawing behind it a fuel-air mix.


Not really stacked... and they do have to have pits and machine rooms so they still wouldn't be continuous even if they were stacked one on top of the other.

They had local banks divided into I think it was 4 sets of floors... and they were accessed from the same EW hallway... the so the floor area (24 floors of it) of the first 8 floor rise would be available for tenant use... and then 16 above the second bank and then 8 floors above the 3rd bank and then no floors above the 4th bank.
 
I don't know about how the circuit protection and switch gear worked. It wouldn't surprise me if it arced and overheated and caused some other gear to explode down there. This is speculation... but the timing seems to link this to the actual plane strike... and I find it hard to believe that these were two isolated but time coordinated events. Whatever exploded did not structural damage to the massive columns at the sub basement level.

The explosions could have occurred no earlier than 10 seconds after the plane strike if it were fuel.... as it would take about that time for it to even drop that far... I suspect the times and what happened when were not something that people recorded or remembered with accuracy... who looks at their watch at these moments? And of course the plane strike would be experienced a second or so after it happened from down in the lobby. I would trust the time memory stuff too much.

The arcs produced by activation of protective devices are very short in time duration and generally don't cause extensive and additional overheating on their own. These devices are tested in pretty extreme fault conditions and designed to operate under just the kind of fault events likely produced by the severing of the mains due to the airplane collision. I think my point was that all such analysis is purely speculative at this point, including the speculation that whatever happened down there didn't structurally damage the core columns. In lieu of further evidence I don't think these type of things can be truly investigated at a level with even an iota of certainty. We can of course conclude that whatever happened wasn't enough to initiate a collapse from the lower levels. :)

I do find the reports sub level explosions interesting mostly because, regardless of the timing, they seem to have been well identified as coming below the lobby level by multiple sources and the fact that terrorists had previously and successfully set off explosions in the lower levels of the WTC.
 
I do find the reports sub level explosions interesting mostly because, regardless of the timing, they seem to have been well identified as coming below the lobby level by multiple sources and the fact that terrorists had previously and successfully set off explosions in the lower levels of the WTC.
Implying you think they were able to rig up the basement to explode in unison with the impacts?
Wouldn't it be more likely that security precautions would have been put in place to prevent it reoccurring since then?
 
Implying you think they were able to rig up the basement to explode in unison with the impacts?
Wouldn't it be more likely that security precautions would have been put in place to prevent it reoccurring since then?

Yes certainly, I'm not implying that I think that is what happened just pointing out there was precedent for such actions at the WTC and there is little doubt explosives are one of the main tools of terrorists, which is why I think such reports are interesting. I imagine if some truck (or just people ) filled with explosives did manage to make it into the basement it wouldn't have been very difficult for them to time the detonation with the plane impacts, pretty sure everyone in the building felt those impacts and especially considering the prevalence of suicide bombers in those extremist groups.

I mean who would have thought terrorists could level both WTC's and fly a plane into the Pentagon with the security precautions that were supposedly in place at NORAD? Easy to argue that it would have been more likely that one or all of those events would have been prevented as well. Obviously sometimes the unlikely scenario is actually the correct one.
 
Yes certainly, I'm not implying that I think that is what happened just pointing out there was precedent for such actions at the WTC and there is little doubt explosives are one of the main tools of terrorists, which is why I think such reports are interesting. I imagine if some truck (or just people ) filled with explosives did manage to make it into the basement it wouldn't have been very difficult for them to time the detonation with the plane impacts, pretty sure everyone in the building felt those impacts and especially considering the prevalence of suicide bombers in those extremist groups.

I mean who would have thought terrorists could level both WTC's and fly a plane into the Pentagon with the security precautions that were supposedly in place at NORAD? Easy to argue that it would have been more likely that one or all of those events would have been prevented as well. Obviously sometimes the unlikely scenario is actually the correct one.
Explosives were ruled out on 911 for causing injury and death, one died on 911 from explosives. Anyone in the basement with explosives brains would be jelly, dead.
UBL was not an idiot, to add explosives to the mix could lead to discovery of the plot; plus the bomb in the WTC in 93 did not bring down the towers - it takes big fires and lots of insulation removed.
NORAD did not patrol over the USA, it used the ADIZ and WARNING areas to intercept outside threats and planes. 911 truth had problems understanding what NORAD did before 911, and that there were zero procedures for NORAD to run intercepts in civilian FAA controlled airspace.
The impact of the planes, with KE of 1300 and 2000 pounds of TNT would be like an explosion in the basement, as the sound/vibration travels faster than the speed of sound in air; you would feel the impact/explosion, and then hear the explosion a second later; two blasts from one aircraft impact. Any transformers in the WTC connected to the impact area might have major problems and could explode... or cause a lot of breakers to ... have to ask a electric power expert...
 
IMO it is safer and grades more efficient to address the "bangs in basement" issue from the perspective of forensic engineering - examining plausibles - there was no prima-facie evidence of explosive damage at that level so why speculate on "how it could have been if we were the terrorists?" We can engage in unlimited speculation about what might have been IF.... - 9/11 discussion abounds with pursuit of truth movement unfounded assertions about "might haves" usually framed in Reversed Burden of DISproof - "We truthers say it was - you lot prove it wasn't."
 
I suspect that shorts of high tension risers would likely case explosions in the switch gear in the basement. Have you seen the various explosions in sub stations? What is exploding? Answer: transformers and switch gear. Look it up!
 
I think perhaps the effects of the fuel/air explosions were greater than supposed, and explain quite adequately all the basement events.
Fuel/air bombs are known to be devastating in confined spaces. How big is this one relative to the two 767s?
To save anyone the effort, it is thirty-three times smaller than just one of them.

I appreciate that the demonstrated bomb is perfectly spread and ignited, but it's obvious that had the 767s' explosions been only 3% "efficient" they would still be as strong as the above, and depositing swathes of fast-moving hot fuel, to boot. (Nice blast wave).
Confining surfaces increased the propagation speed of this wave, and for a moment the same conditions existed as you would find in the combustion chamber of a diesel engine.
So it isn't correct to imply that this explosion wasn't a detonation.
 
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Yes certainly, I'm not implying that I think that is what happened just pointing out there was precedent for such actions at the WTC and there is little doubt explosives are one of the main tools of terrorists, which is why I think such reports are interesting. I imagine if some truck (or just people ) filled with explosives did manage to make it into the basement it wouldn't have been very difficult for them to time the detonation with the plane impacts, pretty sure everyone in the building felt those impacts and especially considering the prevalence of suicide bombers in those extremist groups.

I mean who would have thought terrorists could level both WTC's and fly a plane into the Pentagon with the security precautions that were supposedly in place at NORAD? Easy to argue that it would have been more likely that one or all of those events would have been prevented as well. Obviously sometimes the unlikely scenario is actually the correct one.
You make a good point.
 
This thread is for discussing the seismic evidence from 9/11. Please stay on topic, thanks!
 
I am curious to the sensitivity of the seismic sensors at Lamont Doherty (sp?) what sort of event would trigger a response distinguishing it from background?
 
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.

http://www.consensus911.org/point-tt-7/

psik
 
Then why did the Twin Towers collapse from the area of the plane impacts and not the basements?
It's a topic-stopping question: there is no logically-arguable reason why.
It stops the topic from even being a topic.
This question should have been the first.
It isn't sensible to propose a basement explosion might create a situation where the tower might not collapse immediately but WAIT an hour for a fire to burn eighty floors up before initiating a collapse around the fire - a fire which was burning offices capable of supplying thirty times the heat needed to fail the floors - floors without which the tower's columns couldn't stand.
There is no engineering sense to this proposition. There is no point in continuing a discussion around the seismic monitoring of these impacts and collapses in order to further a nonsensical proposition: an explosion that is both unnecessary, and one that WAITS.
The topic is an argument from disbelief: proponents cannot believe that the towers' columns couldn't stand alone. Nor can they believe that the towers' floors in motion possessed an unstoppable momentum. There are other crucial disbeliefs listed elsewhere... May such beliefs and disbeliefs be replaced with comprehension.
Better science education in schools might help - if it ever were to occur.
[...]
 
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Sure Jazzy, but....... Were there any other mechanisms? :D
Your question is rather general, isn't it?
"Mechanisms"? What do you mean by that, Polly? "Mechanisms" of what sort, and located where?
(And keep your green smiles to yourself.)

Landru said:
So your response is to evade the question?
I thought my response a wordy "NO".
So, to be clear, the seismic evidence does NOT imply controlled demolition at 911.
It implies seismically-registered impacts at times which correlate with the witnessed 911 events.
Not only that, but the seismic signals correlate in proportion with the energies released on each occasion of 20 and 250 tons of TNT. Approximately...

I particularly object to the following:
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.
Content from External Source
"Originated several seconds before" - Is not a legitimate claim unless clock synchronicity were to be proved, along with proof of the true propagation speed of the pressure waves along that particular path.

"abundant physical and testimonial evidence" - There is no physical evidence of CD explosives at all. Explosions within fires do not require explosives, so testimony mentioning "explosions" merely confirms fire. This applies in particular to fuel/air blasts centred within confined volumes with multiple voids (elevator shafts) running down through them to their basements.

Your particular point, Landru, coupled with mine about the delayed effect of the "basement explosion", should have been enough, but the "proponents" are searching for gaps to stand in, so are keen to misdirect one's attention by attributing the fuel/air blasts following the aircraft impacts to some other agency.
So there is a "gap" where the seismic timing may be (and has been) exploited, to conflate with the fuel/air "basement" explosions.
But there has never been any true evidence of CD, of any sort, at all. It's all words, and I thought I was a dreamer...
 
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there is a "gap" where the seismic timing may be (and has been) exploited, to conflate with the fuel/air "basement" explosions.

There is a visualisation of how much fuel would have made these fuel/air explosions at 2m15s in this short (6min) video.

 
There is a visualisation of how much fuel would have made these fuel/air explosions at 2m15s in this short (6min) video.


Thanks. I recommend you make a study of primary and secondary explosion initiation conditions as evidenced in the historical records of fires before you trip lightly down a "planted explosives" route.
Also you should remember that each 4,900 sq yd floor was calorifically equivalent to 200 cu M of aircraft fuel. Approximately.
Any dense smoke-filled volume of space has explosive potential and may suffer random ignition in a fire. Were there any?
Doesn't "any dense smoke-filled volume of space" apply to elevator shafts similarly-filled?
 
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Thus the http://www.consensus911.org/point-tt-7/ web page is based on nonsense and failed opinions
I don't understand it. Certainly not this:
Ranking Methodology
The members of the Panel were asked to rate the validity of the points as follows:
1. strongly agree
2. agree
3. agree, but with (stated) reservations
4. disagree
5. strongly disagree
6. uncertain
If points were rated 4 (disagree) or 5 (strongly disagree), they were either dropped or modified until rankings of 1 (strongly agree) or 2 (agree) were reached by at least 85% of respondents.
If points were rated 3 (agree with reservations) or 6 (uncertain), they were, whenever possible, modified as suggested.
If Panelists were unavailable to vote or refrained from voting through insufficient knowledge, the percentages were calculated on the number who did vote.
Content from External Source
I'm reminded of "The Hitchhiker's Guide"'s spaceship of hairdressers.

The above comes with a homily to the scientific method. So that was all right, then.

There are many things I could say about the above. You will find them here > [...].
 
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Can't be explosions from explosives in the basement because the people in the basement did not have mush for brains after the "explosions"

But people said that they heard "explosions"!!!!!! "Explosions" = Explosives = Bombs = Controlled Demolitions, right?

The problem with the above "equation" is.... A handful of people said they heard explosions, so nut jobs say "must have been bombs", and won't let it go. Just because something goes "boom", doesn't mean it was from a bomb!! A few weeks after 911, there was an incident on a plane traveling toward O'Hare airport where a mentally unstable person tried to get into the cockpit of the plane. Due to the recent events in New York, the authorities were a little "jumpy" and scrambled jets. Living near Chicago, I heard an explosion that I would have sworn was something blowing up. To tell you the truth, I thought it was a plane crash for a moment, as I was always waiting for that, living so close to a major airport. I later found out that it was the scrambling of the passing jets (so I heard) creating sonic booms that I heard. Made sense to me. I had never actually heard that before, so it sounded legit. But, up until that moment, I thought something blew up. So, explosions heard doesn't always mean bombs.

Sort of makes you wonder how I can eat those Pillsbury crescent rolls after the tube "explodes" when I tear off the wrapper. You would think all of that explosive charge, or C4, or Thermite, or whatever would taste bad.

Hmmm....
 
Too right, ever heard a car crash? A peel of thunder? Something heavy dropped from a great height? all can sound like explosions when heard.
Agreed, and the word is so common that it loses meaning. Any rapidly escaping gas is not called an explosion, included the whale carcasses that washed up recently in the UK. They were described as 'exploding' during their autopsies, which is of course absurd.

Also, the average person has never experienced an actual explosion, and only have Hollywood as their point of reference. An elevator crashing down a shaft, or debris or even people hitting the floor have been described as 'explosions'... the 'ear witnesses' to these events often have no real-world ability to describe 'explosions' than I have to describe nuclear physics.
 
In fact the problem is that the term explosion is used for so many things... it has no single meaning and one can't know precisely what the phenomena is that the word is used to describe.

It's like a vehicle... what is it? A car? a motor cycle? a bus? a truck? a train? and so on

" a machine that is used to carry people or goods from one place to another"
 
I think people sometimes use the term "explosion" when it would generally be more accurate to use the term "bang". They don't use "bang" as it sounds a bit silly.
 
There is a visualisation of how much fuel would have made these fuel/air explosions at 2m15s in this short (6min) video.


I am not too sure if the visualizations of the volume comparison's is very accurate.... It compares the 50 CY of fuel to the 2,160,000 cubic yards of volume in the towers. No one said that it filled the entire volume of the towers, just the elevator shafts where the alleged fireball(s) came down. Has anyone ever heard which elevator shaft was said to have the fireball(s)? Was it one of the ones that go the entire height of the towers? Also, "they" look at the elevator shafts as having to "fill" with fuel. In order for fuel to burn, it needs to mix with air and be atomized. An automotive engine burns at about 15:1 ratio. That is 15 parts of air to 1 part of fuel. The fuel is atomized and burns and expands tremendously. That is regular gasoline. I don't know much about the air fuel ration of jet fuel. But a small amount of fuel can take up a large amount of space when it is atomized and ignited.

So, as the fuel was spilled into the elevator shafts and turned into more of a raining aerosol, it could have covered way more ground and still ignited further down. This would have increased the pressure in the shafts and could have easily caused the elevator doors to blow out... giving the burning fuel an escape route. = Fireball blowing out the lobby elevator doors.
 
In order for fuel to burn, it needs to mix with air and be atomized. An automotive engine burns at about 15:1 ratio. That is 15 parts of air to 1 part of fuel. The fuel is atomized and burns and expands tremendously. That is regular gasoline. I don't know much about the air fuel ration of jet fuel. But a small amount of fuel can take up a large amount of space when it is atomized and ignited.

And for the record, the A/F ratio is by mass, not volume. So there's a LOT more air needed than one might think. A quick Google search indicates that the A/F is about the same for jet fuel, though 14.7:1 is the ideal, and fuel can burn at richer or leaner ratios, there's always a buttload of air.
 
There is a visualisation of how much fuel would have made these fuel/air explosions at 2m15s in this short (6min) video.


That is the most misleading and obvious bogus representation of fuel in the elevator shafts that I have seen.
5 Cu.yds. of fuel and the utterly stupid reference to how little could "reach the lobby". More to the point we can visualize 1000 gallons of fuel entering the shaft and falling, as it falls it atomizes or worse, evaporates. Then it ignites. A similar air fuel mix occurs in a piston engine. The resultant explosion in a car's engine cylinder has the expanding gases push the piston down with enough force to move a car or truck weighing several tons. That amount of fuel is minuscule. Even the amount of fuel in a real fuel-air thermobaric bomb is tiny compared to this example of 1000 gallons. Yet for some reason truthers cannot understand how the elevator doors get blown off? Astounding.
 
While reading this, some points occur to me that I think have not been raised.

My recent experience with seismic waves is confined to feel the ground tremble as a heavy train passed the crossing where I was waiting. The train certainly didn't "thump" the ground! But I'm pretty sure if any big force affected the central column, it would transmit that event to the ground, being anchored to it. This is obvious for the plane hitting the building, but it also occurs when a floor detaches: the loss of weight is a sudden upward force that gets added to the column (or rather, a downward force getting subtracted), and would be expected to cause a seismic event at the time, and it doesn't require the falling floor to actually hit anywhere.

Re: the electrical circuits, how hard would you have to "thump" a relay for the contacts to separate?
This possibility applies to both the assumed "live" transmission via the WTC antenna, and the power distribution circuits. Thumped a live circuit breaker lately?
 
"his is obvious for the plane hitting the building, but it also occurs when a floor detaches: the loss of weight is a sudden upward force that gets added to the column (or rather, a downward force getting subtracted)"

There is no upward force if a load is removed from a structure.
 
"his is obvious for the plane hitting the building, but it also occurs when a floor detaches: the loss of weight is a sudden upward force that gets added to the column (or rather, a downward force getting subtracted)"

There is no upward force if a load is removed from a structure.
Consider the 95th floor, and the cross section of the central column between floors 94 and 95. The weight of the 95th floor causes a force, which creates a pressure across the cross section. Since the structure is not moving, there is an equal and opposite force or pressure from below across that cross-section. (A pressure always indicates a force over an area, so with a constant area, a pressure change always corresponds to a change of force.)

Now assume the 95th floor detaches, what happens? Its weight no longer rests on the central column, the downward pressure on the 94/95 cross-section is reduced, and the opposite pressure from below is unbalanced, creating a net upward force until it is relieved. But then the downward pressure of that section of the column on the section below it is reduced, etc., so we have an upward pressure wave travelling down the central column into the bedrock, where it causes a seismic wave that seismometers can register.
 
You don't understand gravity or structure. For one, the floors to not rest ON the columns. The are attached to the SIDES of columns. Gravity is the downward force equal to a constant gravitational constant times the the mass of an object. All loads... mass in a structure is prevented from moving downward by columns. If you remove load the columns do not fly up. They simply have less weight directed to the foundation.

A seismometer is an instrument that responds to ground motions, such as caused by earthquakes, volcanic eruptions, and explosions. It man measure magnitude, direction and intervals between pulses of energy travelling through the earth.
 
You don't understand gravity or structure. For one, the floors to not rest ON the columns. The are attached to the SIDES of columns. Gravity is the downward force equal to a constant gravitational constant times the the mass of an object. All loads... mass in a structure is prevented from moving downward by columns. If you remove load the columns do not fly up. They simply have less weight directed to the foundation.

A seismometer is an instrument that responds to ground motions, such as caused by earthquakes, volcanic eruptions, and explosions. It man measure magnitude, direction and intervals between pulses of energy travelling through the earth.
Why are they attached to the columns? To transfer the downward force. The columns transfer the force to the foundations. That's where my pressure argument starts.

A seismometer does not respond to a ground motion. It responds to a pressure wave, which is a ground motion, but need not have been caused by one. Up in this thread you can see testimony how hurricane waves can cause a seismometer to register, or how footsteps can affect a measurement. A ground pressure wave results in a miniscule ground motion, as does the shifting of several tons of weight. I experienced that myself as the freight train passed by me.

You seem to say that there is no potential energy created when a floor settles on its supports, and hence no energy can be released when the floor detaches. If that was true, rock would not be compressible at all, and could not conduct sound, or rather, it would do so at infinite speed.
 
Why are they attached to the columns? To transfer the downward force. The columns transfer the force to the foundations. That's where my pressure argument starts.

A seismometer does not respond to a ground motion. It responds to a pressure wave, which is a ground motion, but need not have been caused by one. Up in this thread you can see testimony how hurricane waves can cause a seismometer to register, or how footsteps can affect a measurement. A ground pressure wave results in a miniscule ground motion, as does the shifting of several tons of weight. I experienced that myself as the freight train passed by me.

You seem to say that there is no potential energy created when a floor settles on its supports, and hence no energy can be released when the floor detaches. If that was true, rock would not be compressible at all, and could not conduct sound, or rather, it would do so at infinite speed.

Wrong.. You don't understand. Mass has no force. The floors have potential energy like an apple on a tree. The stem falls the potential energy becomes kinetic energy. The force of the falling apple is proportional to the the square of distance it drops.

The energy (force) that the dropping floors is applied to what the mass falls upon... is it concentrated in one point or spread out over a larger area. Strength of floors is given as pounds per square foot. The design load for a wtc office floor was about 50# / SF. It's yield strength would be much higher. Before it yields it would deform.

There is no upward force exerted by columns.


Waves... shock waves such as a building falling are transmitted through a medium.... the earth... soil, bedrock, water and so on. Sound are waves transmitted through air. Different materials conduct energy differently.
 
Jeffrey, YOU do not understand.

The columns, loaded with the weight of whatever load they bear statically, are - well - loaded. Like a spring. Like a string on my guitar when I pull and hold it.

The vibration of the guitar string is not caused by me applying a lateral load on it, but by me releasing the load.

Similarly, releasing the gravity load from a column will result in an elastic upwards response, and possibly to a vertical vibration. Either way, measurable (in principle) by a seismograph. (I just would not want to speculate on the magnitute of the signal)
 
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