At least 3 seconds before any movement was recorded on video and/or photo in the city of New York.
Thus that huge seismic event took place in real 9/11 New York time, 20 seconds earlier.
Because it takes specific seismic signals full 17 seconds, to travel from Manhattan to Palisades Seismic Station in upper NY State.
That movement indicated the 8 seconds taking foreplay of a then following global collapse of that WTC 7 building, those 8 seconds shown as a "slow" sinking of the two penthouses into the roof, which event took a total of 8.3 seconds. Then the whole roof line started moving downwards, named later by NIST as the beginning of its "global" collapse.
NIST explained that 8.3 seconds slow sinking into the roof as a result of the sudden breaking of one column (nr 79) over the height of 5 low floors, situated under the eastern penthouse, then it took the other columns under the western penthouse with it in its fall...........Yep, unbelievable.
Imagine, they thus try to let you believe that the breaking of one internal huge column, 47 stories high, will sent a much stronger seismic signal out than the following breakage of all huge 47 stories high columns, including all 47 floors its cross beams, and the whole outer facade around the building lits steel columns, 47 floors high.
Are you so gullible that you will believe this kind of bended logic?
I was only able to connect the two time-lines regarding that seismic institute its seismometer readings, when NIST published a photograph of the onset of the WTC 7 global collapse in their reports. That Nicolas Cianca photo had a time stamp over it, which was connected to an atomic clock, as NIST explained. Note that they never retracted this time-stamped photo :
This is the start of the sagging of the east penthouse on top of the roof of WTC 7.
Note the time stamp, coupled to an atomic clock by NIST when indexing this photo and then labeling it with that 5:20:46 p.m. time stamp.
The whole sagging of both penthouses into the roof took 8.3 seconds (says NIST). Only then, began the global collapse, as NIST told us so too.
That means that all times provided by LDEO or NIST for this global collapse start, earlier than this 5:20:46 p.m. time stamp moment, plus 8.3 sec., are wrong.
Because this photo shows the earliest movement filmed (the initial sagging of the east penthouse roof), and it took 8.3 more seconds to reach the initiation of the real global collapse, which in fact was the first sign of sinking of the whole roof rim line downwards.
This is my own time table where the NIST table is re-shuffled and LDEO 2001 graph times added :
Those seismometer readings were 17 seconds later recorded than the seismic events in New York took place, and those were the real-time happening events in New York.
When however a (remotely recorded) seismometer reading would exist of such a machine at that time situated inside the WTC buildings, there would not have been any lag-behind of 17 seconds, but 0 seconds instead. This is sadly not the case, so we have to concentrate on the Palisades recordings and show what they meant.