A seismic refraction investigation of a glacial outwash aquifer in southwestern, New Brunswick
Loading...
Date
1998
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of New Brunswick
Abstract
The purpose of this project was to conduct an initial geophysical survey of the Utopia
Delta outwash aquifer using modern seismic refraction methods. The results of the
seismic refraction survey are to aid in the ongoing groundwater investigation conducted
by the University of New Brunswick Groundwater Studies Group.
Overall it was found that the 11.16-Kg weight drop was the most practical seismic source
for the Utopia Delta seismic refraction survey considering energy output and field time
requirements. Site conditions were beneficial for the use of the 11.16-Kg weight drop
because of excellent on-site vehicle access. It was observed that the 12-gauge Buffalo
gun has the highest amount of overall energy output including high frequency energy in
the 83.3 Hz range.
The depth section for Array A revealed an undulating bedrock topology with bedrock
depth varying between 16.6 and 21.8 metres. The water table was mapped at a depth
ranging from 7.7 to 8.9 metres. This range correlates well with average water levels for
October taken at MW-3, located 200 meters west, of approximately 8 metres below
ground (Reeves and MacQuarrie, 1997).
Results from the velocity analysis for array A indicate refractor velocities for the
saturated sand and gravel layer ranging from 2198 m/sec to 3279 m/sec. These values are
generally acceptable for water saturated sand (Kearey and Brooks, 1991).
The lack of quality data for arrays B and C due to windy conditions seriously affected the
interpretation of these sections. In addition, the phantoming technique was not
implemented, and therefore, refractor coverage was minimal.