Tunnel Detection Research (image) DOE/Sandia National Laboratories Caption Researchers deploy instruments for a seismic data acquisition survey parallel to a border fence in California. The photo shows some acquisition equipment, including an SUV-mounted accelerated weight drop to generate seismic waves. Credit Sandia National Laboratories Usage Restrictions Credit to Sandia National Laboratories Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.