Seismic Records of the Major Events in Manhattan
Seismographers recorded the five major events in Manhattan
on September 11.
Here are seismograms recorded by
Lamont-Doherty Earth Observatory of Columbia University, in Palisades, NY
A detailed description of how the data was collected is available
What these charts indicate about the collapse times of the towers is explored
Note that the vertical axes of the charts are not all to the same scale.
The charts for the leveling of WTC 1 and 2 have one-tenth the
vertical magnification of the three other charts.
Note also that the times given on the charts are in Greenwich Mean Time (GMT),
which is four hours ahead of Eastern Daylight Time (EDT),
the time in which
events of the 9/11/01 attack
are usually reported.
The jet impact with 1 World Trade Center
The jet impact with 2 World Trade Center
The leveling of 2 World Trade Center
The leveling of 1 World Trade Center
The leveling of 7 World Trade Center
World Trade Center Attack: Seismograms recorded by LCSN Station PAL (Palisades, NY), ldeo.columbio.edu,