Strange occurrence of stones

The relief of the ocean coast is changing very quickly. Two years ago, stones on the shore were no larger than the level of the adult's belt. But after a strong earthquake in 2016, appeared such giants.

A couple of years ago, the beach looked something like this

How did appear these multi-layered giants there?

Perhaps they were "squeezed" from under the earth's surface, thanks to the movement of tectonic plates, as some local people say.

Or maybe the stones just rolled off the coastal slopes and this sounds like the truth.

Camera: Sony rx10m3
Location: Ecuador coast