Earthquakes are vibrations caused by sudden displacement of land. This was only known recently, however this was portrayed in the Quran 1400 years before it was discovered.
١٦ أَأَمِنْتُمْ مَنْ فِي السَّمَاءِ أَنْ يَخْسِفَ بِكُمُ الْأَرْضَ فَإِذَا هِيَ تَمُورُ
"Yakhasif in Arabic يَخْسِفَ" means downward collapse. "Tamur تَمُورُ" means vibrate. Here the land collapse causes vibrations.
How could an illiterate man who lived 1400 years ago have known that earthquakes are vibrations caused by displacement of land?
In earthquakes most of the energy is released by the mainshock (first quake). The rest of the energy is released by the following weaker aftershocks. The Quran describes both of them:
How could an illiterate man who lived 1400 years ago have known that mainshocks are followed by aftershocks?
The Quran (Koran, the book of Islam) contains scientific knowledge that could not have been known 1400 years ago. It ranges from basic arithmetics to the most advanced topics in astrophysics. You are invited to go through those miracles and judge for yourself.