Seismometers earlier detected the major Hamas attack on Israel

Dec. 2 () –

A study in the field of forensic seismology at Tel Aviv University has identified the seismic signature of the movement of Hamas forces before the major attack on October 7, 2023.

Researchers from the Department of Geophysics at Tel Aviv University’s Porter School of Earth and Environmental Sciences and the Sackler Faculty of Sciences recently analyzed the data recorded at three seismic stations in southern Israel.

The findings reveal that on the morning of October 7, approximately half an hour before the deadly terrorist attack, the stations recorded weak but widespread seismic noise of human origin. Researchers attribute these anomalous seismic amplitudes to the unusual movement of heavy vehicles within the Gaza Strip towards staging points along the Israeli border up to 20 minutes before the breach of the land barrier.

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 movements resulting from preparations for a terrorist attack have been identified by analyzing the characteristics of seismic noise induced by vehicle traffic.

Researchers believe the discovery demonstrates the potential use of seismic detection technology to provide early warnings of terrorist activity. However, they emphasize that the identification of these movements in Gaza was done retrospectively, months after the attack.

The study, led by Dr. Asaf Inbal of the Department of Geophysics at the Porter School of Environment and Earth Sciences and the Sackler Faculty of Sciences at Tel Aviv University, was published in The Seismic Record.

Dr. Inbal explains in a statement: “The Geological Survey of Israel operates a nationwide network of dozens of highly sensitive seismometers that continuously monitor ground movements. This network is primarily designed to detect and locate earthquakes and provide warnings of strong ground shaking caused by large-scale seismic events. magnitude.

“However, three stations in the network, located in Amazia, Ktsiot and Yatir, between 30 and 50 kilometers from Gaza, They recorded unusual levels of seismic noise in the early hours of October 7, 2023.

“This noise can safely be attributed to vehicular activity in Gaza as Hamas terrorists were gathering for the attack. The time period was between 6:00 and 6:30 a.m., before the rocket fire began. “The probability that the recorded signals originated in Gaza is greater than 99.9%.”

Although seismometers are designed to detect extremely weak ground motions, Dr. Inbal notes that the ability to link seismic noise to vehicle movements in Gaza was facilitated by the quiet background seismic noise levels that prevailed in the southern Israel during the early morning hours of that Saturday, which coincided with the holiday of Simchat Torah.

“The movements recorded near the seismometers were in the range of tens of nanometers per second, while the minimum ground motion detectable by humans is several millimeters per second“explains Dr. Inbal.

“The characteristics of the noise originating in Gaza and picked up by Israeli stations are fundamentally different from those recorded at the same stations on previous Saturdays during those hours. We analyzed three years of data from the trio of Israeli stations recorded in the same time period as the prior to the attack.

“We found no instance of a Saturday morning in which correlated amplitudes were recorded at all three stations for more than 10 minutes.. It is important to note that these stations are widely spaced and that each of them is primarily sensitive to seismic noise generated by nearby human activity. For example, the distance between Ktsiot and Amazia is about 80 kilometers and, on previous Saturdays, there was no correlation between the data recorded at these stations.

“On the morning of the attack, when local activity near the stations was minimal, we found widespread and unique seismic amplitudes, which increased monotonically over time as the attack approached. No known natural or human source on the Israeli side could have generated seismic signals with a distribution and intensity similar to those attributed to Hamas movements.

“Although the open-air music festival near Re’im generated some seismic noise, our analysis shows that this noise does not match the strength or location of the noise sources recorded by the Israeli seismic network on October 7” .

Analysis indicates that the detected seismic noise began at 6:00 AM and intensified as the attack approached. Occasionally, the noise contained short bursts strong enough to locate its origin and track its progress.

The location and intensity of these sources in Gaza suggest vehicle movements moving south and north within Gaza, from Rafah in the south to the Erez crossing in the north, during the 30 minutes prior to the attack.

“We have good resolution along the Saladin Highway, a major route through Gaza from Rafah in the south to Beit Lahia in the north,” says Dr. Inbal.

“We can confirm with great certainty that their forces moved along this route at speeds of between 25 and 50 km/h. Observations made from stations located dozens of kilometers from the Gaza border indicate the presence of convoys of heavy vehicles, such as excavators and trucks, transporting the agents. Three minutes before the attack began, we detected noise sources reaching the northern edge of Gaza, near Beit Lahia, and the southern edge, near Khan Yunis.

“At the same time, we continue to receive signals from central Gaza, near Nuseirat. We know that the assault began almost simultaneously along the entire border, so these seismic observations provide further evidence of the extensive deployment of Hamas forces , which probably allowed the simultaneous breach of the land barrier.”