Lamont-Doherty Earth Observatory categorized September 11th as Nuclear Explosion Seismology

LCSN catalog 2001

2001/09/11 16:02:17  42.52N  73.71W   0.0 2.39Ml   13.9 km S of Rensselaer, NY *
2001/10/27 05:42:21  40.79N  73.97W   5.0 2.6 Mc   Manhattan

Seismic records was recorded at each event, details have been withdrawn and kept secret. Lamont-Doherty Earth Observatory only had only two stations running for WTC events 1. PAL and 2. BRNJ.. The two stations are kept in wave form only so select a station and date 9/11/2001. http://www.ldeo.columbia.edu/cgi-bin/LCSN/WebSeis/24hr_heli.pl



William Annin Middle School, NJ (BRNJ) 

BRNJ 49.647 Miles from the World Trade Center or 79.788991016 KM

Lamont-Doherty Earth Observatory, Palisades, NY (PAL) 

61 Route 9w, Palisades, NY 10964PAL 20.878 Miles away from the World Trade Center


World Trade Center Missing Seismic Data

Does "it is not possible to infer what the near-in ground motions must have been" contradict  "Seismic waves generated by aircraft impacts and building collapses".. 

Lamont-Doherty Earth Observatory defined the 9/11 events as
"Nuclear Explosion Seismology" and be found via keywords "Nuclear Explosion Seismology"

6605 Education, 7219 Nuclear explosion seismology
http://adsabs.harvard.edu/abs/2002AGUFM.S11D..03K
"is not possible to infer (with detail sufficient to meet the demands of civil engineers in an emergency situation) just what the near-in ground motions must have been."
Again 

Seismic waves generated by aircraft impacts and building collapses at World Trade Center, New York City. 

But unfortunately, we also conclude that from the distance at which our own detections were made (the nearest station is 34 km away at Palisades) it is not possible to infer (with detail sufficient to meet the demands of civil engineers in an emergency situation) just what the near-in ground motions must have been.
source

"A "sharp spike of short duration" is how seismologist Thorne Lay of Univ. of California at Santa Cruz told AFP an underground nuclear explosion appears on a seismograph" 

So why Did Won-Young Kim became so interested in underground nukes after 9/11?
http://www.ldeo.columbia.edu/news-events/won-young-kim-wins-eastern-section-ssa-award 

Collapse Times and Resistance of the World Trade Center Towers Based on the Seismic Record of 11 September 2001

ARTICLE in SEISMOLOGICAL RESEARCH LETTERS 86(5):1310-1317 · AUGUST 2015 with 13 READS

Impact Factor: 2.16 · DOI: 10.1785/0220140161

Mechanics of Progressive Collapse: Learning from World Trade Center and Building Demolitions

 Preview · Article · Mar 2007 · Journal of Engineering Mechanics

 Mathieu Verdure