Following the earthquake that struck Egypt in the early hours of Monday, 3 August 2026, social media posts began circulating claims that the tremor may have been caused by a “secret underwater nuclear explosion”, or that such a blast had triggered movement along a fault near Egypt. The claims were widely promoted, including by several Egyptian actors.
However, this theory is not supported by any verifiable data. It also conflicts with the earthquake’s location and depth, as well as the methods used by global monitoring networks to detect nuclear explosions.
According to data reviewed by the United States Geological Survey, the earthquake had a magnitude of 5.3 and occurred at 00:00:33 UTC, or approximately 3:00 am Cairo time. Its epicentre was located around 41 kilometres north-east of Suez, at an estimated depth of 10 kilometres within the Earth’s crust.
After reviewing the seismic data, the US Geological Survey explicitly classified the event as an earthquake.
Egypt’s National Research Institute of Astronomy and Geophysics later revised its preliminary estimate of the tremor’s strength to approximately magnitude 5.6, placing the epicentre around 38 kilometres from Suez.
Minor differences between estimates are normal because monitoring networks use different wave-velocity models and different combinations of seismic stations. Such variations do not transform a natural earthquake into an explosion.
Earthquakes and Explosions Leave Different Signatures
Large explosions can generate waves that are recorded by seismometers, but scientists can usually distinguish an explosion from an earthquake by analysing the waveform, the source depth and the way the energy travels.
A tectonic earthquake occurs when two masses of rock slip along a fault that may extend for several kilometres. This movement generates strong compressional and shear waves.
An explosion, by contrast, releases its energy within a very small volume, sending a largely spherical pressure wave outwards from the source.
The Comprehensive Nuclear-Test-Ban Treaty Organisation explains that earthquakes generally produce relatively stronger S-waves, or shear waves, while explosions tend to generate stronger P-waves, or pressure waves, in comparison with their shear-wave output.
Monitoring centres analyse the ratios and frequencies of these waves, together with the source depth and surface waves, to distinguish earthquakes from explosions, which do not produce the same seismic pattern.
The fact that residents felt shaking, or that seismic stations recorded waves, is therefore not enough to conclude that an explosion occurred. The recordings themselves must be analysed, and monitoring networks treated the Suez event as an earthquake, not an explosion.
What an Underwater Explosion Would Produce
An underwater nuclear explosion would not leave only a seismic signature. It would also generate a highly distinct hydroacoustic signal.
Sound travels through water very efficiently and can cross thousands of kilometres while losing relatively little energy, particularly within deep ocean sound channels.
For this reason, the Comprehensive Nuclear-Test-Ban Treaty Organisation established a global network of hydroacoustic stations specifically designed to detect underwater explosions.
The organisation states that only 11 stations are required to monitor the world’s major oceans, and that the technology can distinguish signals generated by nuclear explosions from those caused by underwater earthquakes, volcanic activity or military exercises.
The monitoring system does not rely solely on underwater sound. It also includes 170 seismic stations, 60 infrasound stations that monitor the atmosphere, and 80 stations that detect radioactive particles and gases.
Underwater nuclear explosions can release radioactive particles that eventually reach the atmosphere, providing another form of evidence that would be difficult to conceal.
Claims that a marine nuclear explosion powerful enough to shake Cairo and several Egyptian governorates occurred without producing any hydroacoustic recording, radioactive evidence or report from a specialised monitoring body do not amount to scientific analysis. They remain unsupported speculation.
Could an Explosion Trigger a Fault?
In theory, some extremely powerful explosions may cause very small tremors near the detonation site, particularly when a fault is already under heavy stress and close to slipping.
However, this limited possibility does not support the circulating claim.
The US Geological Survey states that earthquakes associated with nuclear tests have generally been smaller than the explosions themselves. Many detonations caused no earthquakes at all, while any potential effects were usually confined to an area extending only a few dozen kilometres from the blast site.
When the United States conducted the underground Benham nuclear test, with a yield of approximately 1.1 megatons, the related fault movement and tremors were confined to an area within roughly 13 kilometres of the detonation point.
Even the 1971 Cannikin test, which had a yield of five megatons and produced seismic energy comparable to an earthquake of approximately magnitude 6.9, did not trigger other earthquakes across the seismically active Aleutian Islands.
Proving that an explosion caused the Suez earthquake would therefore require evidence that the explosion itself occurred, along with its location, timing and strength. It would then be necessary to demonstrate that it preceded the earthquake and was close enough to affect the relevant fault.
The circulating posts provide none of this evidence.
A Natural Tectonic Explanation Requires No Bomb
The Suez region lies within an area known for tectonic activity and faulting. The Gulf of Suez forms part of a rift system that developed as the Arabian Plate moved away from Africa.
Seismic studies indicate continuing activity along several faults connected to the Gulf of Suez and the Cairo-Suez region.
The area has also experienced moderate earthquakes in the past without any industrial or artificial cause.
This provides a natural geological explanation for the earthquake and is consistent with scientific studies of the region and its history of recurring seismic activity over several decades.
