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Recent Workshop

OGW BG provides formal and informal geophysical training to USGS offices and cooperators. This page provides an overview of a recent workshop conducted by OGW BG. Because training is customized to address specific interests and needs, each training event is unique.

In October 2006, the USGS Office of Ground Water, Branch of Geophysics (OGW BG) conducted a workshop on the multi-channel analysis of surface waves (MASW) land seismic imaging method. This course provided instruction in the basic theory and application of the MASW method.

The MASW method uses surface (Raleigh) waves to image near-surface (1-50 meters) shear-wave velocity structure. This method can be used to delineate and identify:

• unconsolidated material properties
• bedrock surface
• faults
• buried channels
• sinkholes and voids

Recently developed acquisition and analysis methods, including a seismic land streamer and accelerated weight-drop energy source, permit safe, rapid, and inexpensive data acquisition and processing.

The workshop included hands-on field work using a land seismic streamer as well as computer processing, analysis, and interpretation of the field data. Participants also had the opportunity to review and discuss case studies of MASW application in different hydrogeologic environments. The GW1439 workshop participants included USGS ground-water hydrologists as well as cooperator and University scientists.

The workshop included hands-on field work using a land seismic streamer and hands-on computer processing, analysis, and interpretation of the field data. Participants also had the opportunity to review and discuss case studies of MASW application in different hydrogeologic environments. Workshop participants included USGS ground-water hydrologists as well as cooperator and University scientists.

Figure 1. Course participants listen to instructor John Lane (USGS) provide an overview of field activities.	Figure 2. Eric White (USGS) sets up the source/receiver offset.
Figure 3. Course participants assist in the setup of the land seismic streamer system, which is towed behind the vehicle.	Figure 4. The geophones and cable are housed in a protective fire hose for towing.
Figure 5. Class participant attaches metal plate to the accelerated weight drop. The plate and portable accelerated weight drop (seismic energy source) are mounted on the truck and towed ahead of the streamer.	Figure 6. The seismic land streamer used in the class consists of the geophone and a cable, housed in a fire hose. The streamer is towed behind a vehicle, such as a truck.
Figure 7. MASW shear-wave velocity profile (smooth model). Data collected during the course by workshop participants using the land streamer.

You can also read about and see photos from other past OGW BG courses and USGS project support.