Seismic Reflection Methods Applied To Engineering, Environmental, And Ground-Water Problems

The seismic-reflection method is a powerful geophysical exploration method that has<br>been in widespread use in the petroleum industry for more than 60 years. Since 1980, it has<br>been increasingly used in applications shallower than 30 m, and that is the principal subject of<br>this paper. The seismic-reflection method measures different parameters than other<br>geophysical methods, and it requires careful attention to avoid possible pitfalls in data<br>collection, processing, and interpretation. Part of the key to avoiding the pitfalls is to<br>understand the resolution limits of the technique, and to carefully plan shallow-reflection<br>surveys around the geologic objective and the resolution limits. Careful planning is also<br>necessary to make the method increasingly cost effective relative to test drilling and/or other<br>geophysical methods. The selection of seismic recording equipment, energy source, and dataacquisition<br>parameters are often critical to the success of a shallow-reflection project. It is<br>important to carefully follow known seismic reflections throughout the data-processing phase<br>to avoid misinterpretation of things that look like reflections but are not. The shallowreflection<br>technique has recently been used in mapping bedrock beneath alluvium in the vicinity<br>of hazardous waste sites, detecting abandoned coal mines, following the top of the saturated zone<br>during a pump test in an alluvial aquifer, and in mapping shallow faults. As resolution<br>improves and cost-effectiveness increases, other new applications will be added.