Geophones
By Andrew Alden, About.com Guide
Twenty-four geophones are set along the line and wired to the seismograph through a single cable so one shot makes 24 records. These are sensitive at 14 Hz.
Photo (c) 2007 Andrew Alden, licensed to About.com
©2009 About.com, a part of The New York Times Company.
All rights reserved.