Traditional ocean-bottom seismometers often rest on or near the seabed, which limits their mechanical coupling to the underlying sediment and exposes them to water-column noise. As a result, detecting very faint deep-ocean microseismic activity can be difficult, especially in geologically active regions where signal levels are low and deployment conditions are demanding.

In my research, I designed and built a 3 tonne, 3-metre free-fall penetrator, together with embedded monitoring and acoustic transmission systems. The instrument was engineered to descend through the water column at speeds of over 100 mph before embedding itself tens of metres into the seabed, creating a stable, well-coupled platform for seismic sensing.

Once buried in the sediment, the system could record subtle seismic signals with improved fidelity compared with conventional seabed instruments. It also transmitted data acoustically back to the surface, allowing the instrument to function as a remotely monitored deep-sea observatory in an environment where conventional cabling and drilling would be impractical.

Sea trials were carried out in Greece near the Hellenic Arc subduction zone, a region chosen for its strong geological interest and challenging marine conditions. The project combined marine engineering, geophysics, and underwater telemetry in a single experimental system designed for deep-ocean deployment.