Seismic Crew Activity in the Wilmington Area
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Published: Tuesday, September 18, 2012
Updated: Saturday, September 22, 2012 09:09
WILMINGTON TOWNSHIP, Pa.-- Drivers and residents in the Wilmington Area of Lawrence County have noticed strange little probe-like devices along some local roads connected by bright yellow cables. Dozens of these gadgets have been strategically placed around the township. They are equipped with radio antenna and connections to sensors embedded into the earth next to the road.
These roadside devices are called geophones. They are used by seismic crews. According to the company conducting the seismic survey, the geophones collect data to map the rock formations for drillers preparing to tap into the Marcellus and Utica Shale formations.
“We’ll be around this fall and then before you know it our crews will be gone,” Geophysical Pursuit operation manager Rick Drake told WCN. “We’ve received the needed permits for rights-of-ways and permission from local landowners for the survey. Our crews will place the sensors around the area to track vibrations.”
Drake also expressed appreciation to local drivers for watching out for the seismic crews as the position the geophones throughout the Wilmington Township area.
A seismic survey uses technology that tracks reflected sound waves generated by a special vehicle called vibroseis trucks or shaker trucks. The seismic crews use the network of geophones collect data on the frequencies generated by the trucks positioned around the area. Companies like Texas-based Geophysical Pursuit can create three-dimensional images deep below the surface of the ground.
“You could say it is like the way medical technicians use an ultrasound,” Drake said.
Drake says his company is mapping the rock formations for unnamed clients. Those clients are drillers looking to identify the best places to tap into the natural gas deposits in the area.
Similar seismic surveys are underway in nearby communities in Butler and Mercer counties. Drake said the shaker trucks will only generate low-level vibrations and will not cause any damage.
Drillers need to map the rock formations as a preliminary step for drilling into the shale formations under the region
Hydraulic fracturing, or fracking, is the process those drillers will use to free natural gas trapped in the sale. The process injects millions of gallons of chemically treated water and sand into wells to free the gas.
Critics of fracking say more testing and regulation is needed to protect the health and safety of local residents and the local ecosystems.