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Context of '9:37 a.m. September 11, 2001: Unlike Other Three Crashes, Pentagon Attack Does Not Produce Clear Seismic Signal'

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The strike on the Pentagon does not generate a clear seismic signal. A study by the Maryland Geological Survey will state, “We analyzed seismic records from five stations in the northeastern United States, ranging from 63 to 350 km from the Pentagon. Despite detailed analysis of the data, we could not find a clear seismic signal. Even the closest station… did not record the impact. We concluded that the plane impact to the Pentagon generated relatively weak seismic signals.” The study, which is conducted at the request of the Army, states that there are seismic signals for the two planes impacting the World Trade Center and for the Flight 93 crash in Pennsylvania, which allow times to be determined for these events. [Kim and Baum, 2002 pdf file]

Timeline Tags: Complete 911 Timeline, 9/11 Timeline

Smoke rising, minutes after Flight 93 crashes in Pennsylvania.Smoke rising, minutes after Flight 93 crashes in Pennsylvania. [Source: CNN]Exactly when Flight 93 crashes is unclear. According to NORAD, Flight 93 crashes at 10:03 a.m. [North American Aerospace Defense Command, 9/18/2001] The 9/11 Commission gives an exact time of 11 seconds after 10:03 a.m. It will claim this “time is supported by evidence from the staff’s radar analysis, the flight data recorder, NTSB [National Transportation Safety Board] analysis, and infrared satellite data.” It does note that “[t]he precise crash time has been the subject of some dispute.” [9/11 Commission, 6/17/2004] However, a seismic study authorized by the US Army and drafted by scientists Won-Young Kim and Gerald Baum to determine when the plane crashed will conclude that the crash happened at 10:06:05 a.m. [Kim and Baum, 2002 pdf file; San Francisco Chronicle, 12/9/2002] The discrepancy is so puzzling that the Philadelphia Daily News will publish an article on the issue, titled “Three-Minute Discrepancy in Tape.” This notes that leading seismologists agree on the 10:06 a.m. time, give or take a couple of seconds. [Philadelphia Daily News, 9/16/2002] The New York Observer will note that, in addition to the seismology study, “The FAA gives a crash time of 10:07 a.m. In addition, the New York Times, drawing on flight controllers in more than one FAA facility, put the time at 10:10 a.m. Up to a seven-minute discrepancy? In terms of an air disaster, seven minutes is close to an eternity. The way our nation has historically treated any airline tragedy is to pair up recordings from the cockpit and air traffic control and parse the timeline down to the hundredths of a second. However, as [former Inspector General of the Transportation Department] Mary Schiavo points out, ‘We don’t have an NTSB (National Transportation Safety Board) investigation here, and they ordinarily dissect the timeline to the thousandth of a second.’” [New York Observer, 2/15/2004]

Entity Tags: 9/11 Commission, North American Aerospace Defense Command, Federal Aviation Administration, Won-Young Kim, Mary Schiavo, Gerald R. Baum

Timeline Tags: Complete 911 Timeline, 9/11 Timeline

Flight 93 crashed in the Pennsylvania countryside. Resue vehicles arrive in the distance.Flight 93 crashed in the Pennsylvania countryside. Resue vehicles arrive in the distance. [Source: Keith Srakocic/ Associated Press]Flight 93 crashes into an empty field just north of the Somerset County Airport, about 80 miles southeast of Pittsburgh, 124 miles or 15 minutes from Washington, D.C. Presumably, hijackers Ziad Jarrah, Ahmed Alhaznawi, Ahmed Alnami, Saeed Alghamdi, and all the plane’s passengers are killed instantly. [CNN, 9/12/2001; North American Aerospace Defense Command, 9/18/2001; Guardian, 10/17/2001; Pittsburgh Post-Gazette, 10/28/2001; USA Today, 8/13/2002; Associated Press, 8/21/2002; MSNBC, 9/3/2002] The point of impact is a reclaimed coal mine, known locally as the Diamond T Mine, that was reportedly abandoned in 1996. [Pittsburgh Tribune-Review, 9/12/2001; St. Petersburg Times, 9/12/2001; Pittsburgh Tribune-Review, 9/11/2002] Being “reclaimed” means the earth had been excavated down to the coal seam, the coal removed, and then the earth replaced and planted over. [Kashurba, 2002, pp. 121] A US Army authorized seismic study times the crash at five seconds after 10:06 a.m. [Kim and Baum, 2002 pdf file; San Francisco Chronicle, 12/9/2002] As mentioned previously, the timing of this crash is disputed and it may well occur at 10:03 a.m., 10:07 a.m., or 10:10 a.m.

Entity Tags: San Francisco Chronicle, Ziad Jarrah, Ahmed Alhaznawi, Saeed Alghamdi, NBC, Ahmed Alnami

Timeline Tags: Complete 911 Timeline, 9/11 Timeline

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