Seismic refraction is a geophysics application that uses the movement of seismic waves on geologic layers to determine the conditions below the surface. This allows you to identify the structures of rocks and soils that are present. It is a common test before scheduling drilling or groundwater sampling, as it gives insight into the depth and quality of the subterranean environment, ensuring a targeted, more successful outcome. Below is a brief overview about how this test works and why you should consider it.

What Is It?

Different types of soil and rock produce different seismic velocities when a sound wave hits them. This means that the acoustic energy waves are refracted when they cross between substances of differing seismic velocities. By recording these speeds and calculating their exact velocities, you can identify what materials are below the surface. This helps you determine the suitability of the area for drilling, groundwater sampling, and other projects.

During seismic refraction, your geoscientist will usually use a small, controlled explosion to provide energy for the seismic waves, with the strength depending on the depth of the application. Then, geophones at the surface detect the spread of seismic waves resulting from this charge.

What Are the Benefits?

Seismic refraction offers an accurate picture of underground structures. It is a helpful approach in rippability analysis, which is a test that tells you how easy—or difficult—it will be to mechanically excavate specific areas of rock or soil. Seismic refraction also allows you to map the depth to a water table precisely, making groundwater sampling easier and more exact. You can even determine how deep the bedrock layer is with this method.

Additionally, earthquake researchers utilize seismic refraction to discover and map fault lines. This means they can determine when the next earthquake is likely to happen, as well as the location of the fault. No matter how you employ this method, it provides an in-depth snapshot of the subsurface. Furthermore, it requires fewer source and receiver locations than other methods and minimal processing, while still providing results that are easy to interpret.

If you need to schedule seismic refraction for your project, contact GeoTek Alaska in Anchorage. Since 2002, this team of geoscientists has been serving clients throughout the state. In addition to geophysical services like seismic refraction, they provide soil and groundwater sampling, auger drilling, and well monitoring. They have the skills, expertise, and tools to meet your goals and deliver dependable results. Call (907) 569-5900 to speak to a team member about your needs. Visit them online to learn more about their services.