Residents of Cairo and several other governorates felt an earthquake early Monday. The National Research Institute of Astronomy and Geophysics (NRIAG) said the quake had a magnitude of 5.6, struck at a depth of 10 kilometers, and was centered 38 kilometers north of Suez.
Hesham El-Askary, professor of Earth systems science and remote sensing at Chapman University in California, told Al Manassa that human activity may have been a contributing factor.
NRIAG President Bassem Nabawy said Monday on the Sadah Elbalad program that six aftershocks had been recorded so far, none of which residents felt. He said more were expected over the next 48 hours.
Aftershocks are a natural phenomenon and are usually weaker than the main earthquake, El-Askary told Al Manassa. They begin immediately afterward, then gradually decrease in intensity and frequency over hours or days until they fade, he added.
The US Geological Survey defines aftershocks as smaller earthquakes that occur in the same area after the main quake as the Earth’s crust continues to readjust following the release of large amounts of energy.
These tremors usually occur near the fault that caused the earthquake and may continue for days, weeks, or months, and in some cases for years, depending on the strength of the main quake and the region’s geology. They become less likely as the earthquake’s depth increases, particularly beyond 30 kilometers.
Geologists view these smaller tremors as a natural sign that the fault is gradually releasing its remaining energy and returning to a stable state. A geological fault is a fracture or crack in the Earth that allows blocks of the crust on either side to move, explained El-Askary.
He added that the earthquake struck an area where seismic activity is considered “unusual,” warranting further research into its cause.
Initial indications suggested that human activity, particularly intensive natural gas extraction in the eastern Mediterranean, may have been a contributing factor, El-Askary explained to Al Manassa. But he stressed that this was only a preliminary possibility and that detailed data and geological studies were needed before any firm scientific conclusions could be reached.
El-Askary denied that the seismic activity indicated Egypt was entering a new earthquake zone, saying earthquakes and aftershocks did not mean the country had become part of an “earthquake belt.”
According to the US Geological Survey, scientists cannot precisely predict when aftershocks will occur or how strong they will be. They can, however, estimate the likelihood of aftershocks following major earthquakes based on patterns recorded after previous quakes and the characteristics of the main earthquake.
Egypt’s Ministry of Health and Population said in a statement Monday that field monitoring had identified only a limited number of minor injuries caused by the earthquake. Those injured were treated immediately, with no deaths or disruptions to hospital operations reported.
The ministry also placed all health facilities on maximum alert and declared a 48-hour state of emergency as a precaution against possible aftershocks.
The Ministry of Transport, meanwhile, said rail services were operating normally on all lines, with trains running to schedule.
