What caused the Red Sea to widen?

The Red Sea is widening due to the tectonic activity associated with the East African Rift system. This rifting occurs as the African tectonic plate splits into two smaller plates, causing the seafloor to stretch and create new oceanic crust. As a result, the Red Sea is slowly expanding, with new magma rising from the mantle to fill the gap. This geological process contributes to the ongoing formation of the sea and the surrounding landmasses.