Buffalo Seismic Source
Efficient, Safe, Cheap

Quality seismic data, especially seismic reflection, requires a repeatable, efficient seismic source generating a high-frequency, high-energy pulse and low source generated noise.

The buffalo can satisfy these criteria, and be tuned to the exact application by varying firing depth, cartridge load and number of stacks. The buffalo is supplied complete with trigger switch, ready to use.
Firing below the surface gives the advantages of:

• Lower near-source attenuation
• Higher frequency P-waves
• Reduced Ground-Roll
• Reduced Airwave
  

Comparison with the sledge-hammer in a wide variety of geological situations confirms the advantages of the Buffalo as shown in Figure 2

Buffalo Seismic Source
Description

An auger-fitted Buffalo may be used as a source of high-frequency seismic energy (Fig. 1). It consists of three component parts:

1) A tube 1.4 m in length, 33 mm in diameter with a robust metal cross-handle fixed just below the top end of the tube while the bottom end is threaded internally to allow the cartridge chamber to be screwed in. An auger thread is added to the tube to help to drive the device deeper into the ground to ensure good coupling and to prevent recoil and escape of high pressure gas.
2) A cartridge chamber comprising a 70 mm long steel cylinder machined internally to house a 12-gauge shotgun cartridge and fitted to the buffalo's tube by a screw thread.
3) A firing pin made from thin steel rod inserted inside the main tube where its tip rests on the primer cap of the cartridge.
A cylindrically shaped impact switch fits into one end of the tubular cross-handle. The buffalo is deployed in a previously prepared hole in the ground. After firing, the cavity produced is a relatively smooth sphere with a radius of approximately 60 mm.
The characteristics of the Buffalo signal are largely determined by the nature of the cartridge fired. Buffalos are available from Allied Associates to fire 8 gauge, 12 gauge and 9mm cartridges. Buffalos can fire pelleted cartridges or blanks, but blanks are preferred on both efficiency and safety grounds. Yachting blanks are recommended as they offer more energy.
Operating procedure.
1. Ensure the cartridge chamber is empty.
2. Ensure the buffalo is clean internally with no mud or rust particles which may obstruct the firing orifice between the shaft and the chamber.
3. Remove the firing pin.
4. Select one cartridge from the clearly marked carrying box and insert it in a clean chamber.
5. Ensure the firing pin is not in the buffalo, and screw the cartridge chamber onto the buffalo. This is easiest done with the buffalo inverted. Tighten the chamber with a pipe wrench.
6. Keeping the buffalo inverted carry it to a pre-drilled hole, which should have a closely matching diameter and be water-filled.
7. Insert the buffalo, screwing the auger flight (if fitted) into the ground.
8. Lower the firing pin gently into the buffalo so that it rests on the cartridge.
9. Connect the impact switch to the appropriate tube in the buffalo handle.
10. To fire the buffalo, lift the firing pin 100 mm and drop it. Do not lean over the buffalo while firing.

Safety

• Shotgun cartridges used are all blanks but can still cause injury if accidentally fired. Treat then gently and keep live cartridges in one place only.
• Never place firing pins in the buffalo before the buffalo is inserted in the ground.
• Never lean over the buffalo when it is being fired.
• Beware of back injury and muscular strain if trying to use brute force to insert or remove buffalo from the ground.