• journal_title：Journal of Environmental & ; Engineering Geophysics
• Contributor：Seth S. Haines
• Publisher：Environmental & Engineering Geophysical Society
• Date：2006-
• Format：text/html
• Language：en
• Identifier：10.2113/JEEG11.1.9
• journal_abbrev：J ENVIRON ENG GEOPHYS
• issn：1083-1363
• volume：11
• issue：1
• firstpage：9
• section：Research Article

Vibrational seismic sources frequently provide a higher-frequency seismic wavelet (and therefore better resolution) than other sources, and can provide a superior signal-to-noise ratio in many settings. However, they are often prohibitively expensive for lower-budget shallow surveys. In order to address this problem, I designed and built a simple but effective vibrator source for about one thousand dollars. The “EMvibe” is an inexpensive electromagnetic vibrator that can be built with easy-to-machine parts and off-the-shelf electronics. It can repeatably produce pulse and frequency-sweep signals in the range of 5 to 650 Hz, and provides sufficient energy for recording at offsets up to 20 m. Analysis of frequency spectra show that the EMvibe provides a broader frequency range than the sledgehammer at offsets up to ~10 m in data collected at a site with soft sediments in the upper several meters. The EMvibe offers a high-resolution alternative to the sledgehammer for shallow surveys. It is well-suited to teaching applications, and to surveys requiring a precisely-repeatable source signature.