According to B. B. Lal, former DG of ASI, Kalibangan site shows that an earthquake occured around 2600 BC, which brought to an end the Early Indus settlement at the site. It is perhaps the earliest archaeologically recorded earthquake.
The Mauryan art is believed to be inspired from Achaemenid or Persian influence. We can find a lot of similarities in terms of form and style in the inscriptions of Ashoka and the Persian king Darius.