A Seismic Victory in Gaza: Mapping the Tunnels of the “Gaza Metro”

According to sources, Hamas’ tunnels under Gaza extend “a few dozen miles.” Other sources believe these tunnels extend hundreds of miles and rival the underground of a major European city. This has caused some commentators to refer to Hamas’ tunnels as the “Gaza metro.” The ‘Gaza metro’: The mysterious subterranean tunnel network used by Hamas | CNN. Whatever their length, they shield fighters from surveillance and allow movement without fear of observation or attack. What if these tunnels could be precisely located? Rather than being safe locations, they would become death traps.

Commentators suggest the tunnels give Hamas an asymmetric advantage. The noted publication Foreign Affairs, states that only

[b]ulldozers can be used to expose tunnels during a ground operation. Drones, robots, or dogs can help clear tunnels. There might be a need to enter the tunnels to rescue hostages, as a measure of last resort. … This is how most states have eliminated subterranean threats in the past, and this is what Israel should do, as well. (November 9, 2023, “Israel Must Destroy Hama’s Tunnels, Demolishing the Groups Infrastructure Is More Important Than Eliminating Its Leaders”)

In short, according to Foreign Affairs, only personnel on the ground can locate and destroy Hamas’ tunnels. Of course, Israeli personnel searching open ground to locate the entrances to the tunnels would be exposed to attack.

Currently used seismic equipment could locate tunnels using a system of geophones and pulse generators. However, personnel placing the geophone data acquisition equipment on the surface would be exposed to small arms fire and potential capture. The need to potentially expose personnel to attack while emplacing geophones would seem to defeat use of this well understood technology that could readily and accurately locate Hamas’ tunnels.

At its most basic, a seismic system can map layers in the earth’s surface. To do so, as seen in the figure below, a source generates a seismic wave. This wave travels through the earth and reflects off reflecting subsurface layers, such as the roof and floor of a tunnel, and these reflected waves are collected by a receiver. A source and be anything that generates a seismic wave. Currently, stamper trucks and explosives are frequently used to generate these waves. Seismic receivers are generically referred to as “geophones.” Geophones collect seismic data, i.e., seismic waves, and map the earth’s subsurface.

Current seismic technology readily available from the oil field will allow identification (and then destruction) of these tunnels. Wireless Seismic METIS (Multiphysics Exploration Technology Integrated System) uses a seismic recording channel collected by autonomous drones. These drones also drop DART (Downfall Air Receiver Technology) receivers, i.e., geophones. The DARTs are dropped by the drone and impale themselves into the ground creating a system of geophones to model the subsurface data. This system was thoroughly evaluated in Papua New Guinea in 2018. Wireless Seismic News — METIS field test yields excellent results. A single drone dropped 60 DARTs in one hour and these drones recovered “real time seismic data” thereby imaging subsurface data of underground voids. Precision guided artillery shells could provide the seismic source needed for the geophones to collect subsurface data. The DART’s would be dropped inside Gaza to model any location, i.e., not just locations close to where Israeli troops are located. Thus, METIS could accurately map the entire Gaza strip.

Once the location of the tunnels is known, they can be destroyed using deep penetrating bombs fused to detonate deep in the ground and dropped from aircraft. This could potentially interdict the entire system of tunnels. Even an extensive metro-like system of tunnels could be defeated if important chokepoints could be detected and collapsed.

Finally, this technology could resolve the ongoing factual dispute over whether Hamas has placed tunnels underneath hospitals, United Nations positions, schools, and other places that are protected from attack. While not a panacea, the METIS system could answer these basic questions and, potentially, turn Hama’s tunnels into a death trap for fighters using the tunnels. At least, it would mitigate any asymmetric advantage Hama’s tunnels provide.

This article was originally published by RealClearDefense and made available via RealClearWire.