(We just couldn't stop ourselves)
When the entire field of play had been covered by the six rolling rows of Texans a different type of experiment was performed. This time the 600 Texans were all spread out so as to cover the entire area of the experiment at the same time as seen in the photograph below. The Texans were programmed to record data for three seconds, every 30 seconds, 999 times (a little over 8 hours). Every 30 seconds a shot was made next to a Texan. If the shot was good then the gun was moved to the next Texan and the shot made there, and so on until a shot had been made next to all of them.
The last experiment done at the site was what is called a downhole experiment.
Basically, two wells are drilled, geophones are lowered into the wells, an
active source is set off somewhere between the two wells, the geophones are
raised some amount, and the whole thing is repeated until the geophones reach
the surface. Then they are lowered into the wells again and the whole process
is repeated for a shot hole in a new location between the wells.
Below are the two downhole geophones that were used for the this part of the experiment.
Below are "GG" and Bix placing marks on the downhole geophone cables every 50 centimeters.
The two wells were about 20 meters apart and were about 15 meters deep. There were 60-something shot holes between the two wells. The geophones were lowered to the bottoms of the wells and raised 50 centimeters after each shot. The point of this experiment was to give the geophysists an idea of the velocity of the sound waves through the various layers of rock in the area of the experiment. This information was needed to make sense of all of the data that was gathered with the Texans.
Since the area was contaminated with TCE, the geophones that were placed down the wells had to be decontaminated at the end of the experiment.
DIRECT LINKS TO PAGES:
ANATOMY OF AN EXPERIMENT
HOW TO DO A SEISMOLOGY EXPERIMENT
600 HEAD OF TEXANS
MORE FUN AND GAMES
ALL GOOD PROJECTS MUST COME TO AN END