A different survey was performed in 2001, combining remote sensing techniques such as side scan sonar and an echo sounder with visual survey by archeologist divers.
Examples include: ferroelectrics - high dielectric capacitors, non-volatile memories; ferrites - data and information storage; solid electrolytes - energy storage and conversion; piezoelectrics - sonar; semiconducting oxides - environmental monitoring.
The second hit under the bridge with a dull thud, much louder than the duds heard only on sonar but lacking the whacking noise which accompanies a wholehearted explosion.
