Timing and Recording
Timing is critical when using recording systems that use absolute time (non-cabled). It is important to understand how to time shots based on source types. Select the link to see available options (explosive initiation systems will require supervision due to liability reasons).
Point Sources
The chart above shows calculated source energies related to commonly used sources. The actual energy transmitted into the earth will be largely related to the source coupling. Attenuation is related to the medium in which the seismic waves travel.
Hammer
This is a sledgehammer hitting a metal plate to induce elastic waves into the ground.
Accelerated Weight Drop
A source attached to a vehicle that uses a spring or high gas pressure to accelerate a mass into a plate coupled with the ground. We have the United Service Alliance A200 P&S, and the Propelled Energy Generator (PEG-40Kg) source. The specifications can be found in the link below.
Learn more about Accelerated Weight Drops
PEG-40Kg – EPIC
Betsy Seisgun
Uses a blank 8 or 12 Ga shotshell placed underground (~18”) to fire, creating elastic energy.
Explosive
Explosive sources typically range from 150g to 907kg. They generally require drilling small to large holes depending on shot size. We have licensed and credentialed personnel to transport, store and explosives onsite. This lowers large transportation costs and storage issues associated with many projects.
Source Comparison and Testing
Vibratory Sources
We do not contain these sources in the inventory. However, we have agreements with other agencies such as Natural Hazards Engineering Research Infrastructure (NHERI) and New Mexico Institute of Mining and Technology (NMT).
NHERI
NHERI is located on the University of Texas at Austin campus. The equipment facility is not located on the main campus. However, it is located in Austin, Texas, nearby. They maintain an assortment of P & S vibratory vehicles. Prices and associated costs can be found here.
Learn more about NHERI
Experimental Protocol (Prices)
NMT
NMT is located in Socorro, New Mexico. They have an Industrial Vehicles International (IVI) mini-vibe. This is a trailer-mounted vertical only vibrator with a 4500-lb. force. Water tanks are included on the trailer to add weight. The imaging depth is generally 600 – 800 meters.
