Israel plans to flood Gaza tunnels, risking geological damage

Israel is planning to adopt drastic measures in its confrontation with Hamas, including flooding the tunnels beneath the Gaza Strip. Given that an estimated 310 miles of passages and tunnels may exist under the Strip's 141 square miles, this could potentially result in substantial geological and ecological damage.

There is ongoing conflict in the Gaza Strip. Israel continues its incursion into the territory, home to approximately 2.3 million Palestinians. However, victory is uncertain. Besides the visible aspects of the conflict, Israelis must combat what lurks underground.

The soil beneath the Strip is riddled with tunnels. This complex and extensive network -  potentially spans 310 miles.

These tunnels represent more than simple, continuous excavations. Beneath the surface, Hamas has constructed an alternative world complete with warehouses, training rooms, weapon production, and storage facilities. It is believed that individuals kidnapped during a Hamas attack on southern Israel on November 7th were kept there.

For the Israelis, Gaza poses a formidable challenge. Fighting underground in tunnels implies a drawn-out, bloody, and destructive engagement, a reality the Israelis are cognizant of. General Herszon Ha-Kohen of the Israel Defense Forces' reserve likened the war in the Gaza Strip to the conflict in Ukraine.

Gaza is more fortified than Mariupol or Bachmut in Ukraine. Both of these cities presented significant difficulties for the Russians. Israelis hope that by flooding the tunnels, they will also submerge the hidden leaders of Hamas, particularly those behind the October attack.

What will happen in Gaza is still uncertain. If Israelis proceed with their plan to pump seawater into the tunnels, they will inevitably flood the underground fortifications and potentially anyone and anything within them. This includes fighters and possibly unrescued or unexchanged prisoners.

Predicting the outcome is challenging. So challenging, in fact, that none of the geologists we contacted wanted to be named.

You need documentary materials, such as a geological cross-section, and knowledge of the depth of these fortifications underground. If these are indeed tunnels, this implies that the ceiling is supported, and the tunnels are bored into the rock. The outcome depends on the overburden, or what is above the tunnels. If it's limestone or sandstones, a disaster could ensue as they start to crumble, potentially resulting in a catastrophic situation with collapsing terrain and structures.

The Israelis plan to use seawater to flood the tunnels, which could induce a major humanitarian disaster. The Mediterranean Sea is much saltier than the Baltic Sea.

If the water reaches underground potable water sources, salinization could occur, rendering the water undrinkable. This would pose a serious issue for Gaza, where water supply is already unstable, following previous disruptions by Israelis.

Without sufficient knowledge of topography and geology, things are speculative. The landscape suggests that the Strip is located near a fault line, and if this is the case, any water Israelis pump in is likely to find a way out. The outcome greatly depends on the types of rocks comprising the terrain.