Researchers from Tel Aviv University‘s Porter School of the Environment and Earth Sciences have uncovered critical seismic evidence that preceded the October 7th terrorist attack. The study provides unprecedented insights into pre-attack movements by analyzing data from three seismic stations in southern Israel.
The groundbreaking research detected unusual seismic signatures approximately 30 minutes before the assault. Specifically, the stations recorded weak but widespread human-induced seismic noise, indicating significant vehicular activity. Scientists identified anomalous seismic amplitudes consistent with heavy vehicle movements within the Gaza Strip, tracing routes toward border organizational points up to 20 minutes before the ground barrier was breached.
This forensic seismology study represents a significant advancement in understanding pre-attack movement patterns. It offers a scientific approach to analyzing complex security events through geophysical data analysis.
The researchers explain that forensic seismology is often used to monitor conventional and nuclear explosions. However, this is the first time in history that weak ground motions resulting from preparations for a terrorist attack have been identified by analyzing the characteristics of seismic noise induced by vehicular traffic. They believe the discovery demonstrates the potential usage of seismic-based sensing technology to provide early warnings of terrorist activity. However, they emphasize that the identification of these movements in Gaza was conducted retrospectively, months after the attack.
The study, led by Dr. Asaf Inbal of the Department of Geophysics at Tel Aviv University’s Porter School of the Environment and Earth Sciences and Sackler Faculty of Exact Sciences, was published in The Seismic Record, a journal of the Seismological Society of America.
Dr. Inbal explains: “The Israeli Geological Survey operates a nationwide network of dozens of highly sensitive seismometers that continuously monitor ground motions. This network is primarily designed to detect and locate earthquakes and provide warnings of strong ground shaking caused by large-magnitude seismic events. However, three stations in the network—located in Amazia, Ktsiot, and Yatir, between 30 and 50 kilometers from Gaza—recorded unusual seismic noise levels early in the morning of October 7th, 2023.
This noise can be attributed with confidence to the vehicular activity in Gaza as Hamas terrorists gathered for the attack. The time frame was between 6:00 and 6:30 AM before the rocket fire began. The likelihood that the recorded signals originated from Gaza is over 99.9%.”
Although the seismometers are designed to detect extremely weak ground motions, Dr. Inbal points out that the ability to link the seismic noise to Gazan vehicle movements was facilitated by the quiet background seismic noise levels that prevailed in southern Israel during the early hours of that Saturday morning, which coincided with the holiday of Simchat Torah.
The analysis indicates the seismic noise detected began at 6:00 AM and intensified as the attack approached. Occasionally, the noise contained short bursts strong enough to pinpoint their source and track their progress. The location and intensity of these sources in Gaza suggest vehicle movements advancing southward and northward within Gaza, from Rafah in the south to the Erez crossing in the north, during the 30 minutes leading up to the attack.
“We have good resolution along Salah al-Din Road, a major thoroughfare crossing Gaza from Rafah in the south to Beit Lahia in the north,” says Dr. Inbal. “We can confirm with high certainty that their forces moved along this route at speeds of 25 to 50 km/h. Observations from stations dozens of kilometers from Gaza’s border indicate convoys of heavy vehicles such as bulldozers and trucks carrying operatives. Three minutes before the attack began, we detected noise sources reaching the northern end of Gaza near Beit Lahia and the southern end near Khan Yunis. At the same time, we continued receiving signals from central Gaza, near Nuseirat. We know the assault began almost simultaneously along the entire border, so these seismic observations provide further evidence of the extensive deployment of Hamas forces, likely enabling the simultaneous breach of the ground barrier.”
