This is the dictation tape made by a lawyer which captures the sounds of the blast which destroyed the Oklahoma Federal Building on April 19th, 1995. Note the sounds of a rattle which precedes the blast by one second. This sound is the surface wave from the ANFO Truck Bomb which arrives ahead of the airborne concussion, traveling through the Earth's surface. 4.2 seconds ahead of the start of the rattle, a "thump" is heard on the tape, overlapping the second syllable of the word "attorneys".
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Events marked on the jpg file
http://www.whatreallyhappened.com/RANCHO/POLITICS/OK/spectrum2.jpg
1. The thump at -4.2 seconds.
2. An airborne event which arrives at the correct place to be associated with event 1, if it originates at the same location as the truck bomb itself.
3. This marks the start of the arrival of the surface wave from the truck bomb. On the tape, this can be heard as a rattle building under the lawyer's voice. Note that unlike the lawyer's voiceprints, which show clear banding in frequency, the sounds from the truck bomb surface wave are smoothly distributed in the lower frequencies.
4. This is the arrival of the airborne concussion from the truck bomb. Like the surface wave, this signal lacks the striations of the lawyer's voice. The most notable difference is the sudden transition to high frequency components.
Note that the Surface Wave / Air Wave delays are identical in both cases, indicating similar distances from the recording device.
When I originally heard this tape, I discarded the "pop" at the -4.2 second mark as just noise on the tape. However, when the Water Board tape (which follows) also had an artifact at the -4.2 second mark, I ran a frequency domain audio spectrogram on the lawyer's dictation tape. The spike corresponding to the pop at the -4.2 second mark is circled. The other event marks were added later. The stripe at the top is electronic noise, possibly from the dictation machine itself.
At the time when the Truck Bomb exploded outside the Murrah Federal Building on April 19th, The Oklahoma Water Board was meeting in a building diagonally across the street. 4.2 seconds prior to the truck bomb blast, a loud "thump" is heard on the tape, just as the speaker finishes the phrase," are four elements that I have to..".
On this tape, the speaker pauses after the thump is heard, and just prior to the main blast, if you listen real close, other voices can be heard just starting to speak up.
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From the above evidence, it is clear that an event which generated a high frequency surface wave which preceded the main truck bomb blast by 4.2 seconds. This event was recorded at two different locations at distances of 100 yards and 1/3 of a mile. Because the 4.2 second interval remains constant at both distances, theories of mechanism producing echoes are eliminated. Because the spectrogram of the lawyer's tape shows BOTH surface and airborne waves separated by 4.2 seconds from BOTH surface and airborne waves of the truck bomb, arguments of a surface/air phenomenon are invalid. Two events at the Murrah building 4.2 seconds apart produced two sets of surface/air pairs 4.2 seconds apart at the lawyer's office.
These images are scans of the seismographic output from the Norman Oklahoma Z-axis recorder for April 19th and May 23rd; the bombing and the demolition respectively. This is the raw data which led Ray Brown and Charles Mankin to decide that there may have been a second explosion. It turns out that the 10 second delay is caused by differing propagation times through the layers of shale and sandstone that lie under Oklahoma City.
April 19th: The Bombing of the Murrah Building
http://www.whatreallyhappened.com/RANCHO/POLITICS/OK/ok_geo.jpg
http://www.whatreallyhappened.com/RANCHO/POLITICS/OK/lo_19.jpg
http://www.whatreallyhappened.com/RANCHO/POLITICS/OK/hi_19.jpg
May 23rd: The Sequenced Demolition of the Murrah Building
The additional spikes on this record are caused by wind flexing the radio antenna which is used to transmit the data to the Oklahoma Geological Survey.
Seismographic record of the Murrah Building Demolition
http://www.whatreallyhappened.com/RANCHO/POLITICS/OK/lo_22.jpg
http://www.whatreallyhappened.com/RANCHO/POLITICS/OK/hi_22.jpg
Note that the 8 second long sequenced demolition of the remainder of the Murrah Building yielded a trace the same length as the original bombing. The first trace, if indeed a single explosion, should be shorter. But it isn't, suggesting that BOTH events consisted of multiple sequenced detonations over several seconds' duration.
