Дигха Никая 1:558
SUJATOPuna caparaṁ, ānanda, yadā tathāgato anuttaraṁ sammāsambodhiṁ abhisambujjhati, tadāyaṁ pathavī kampati saṅkampati sampakampati sampavedhati.
Furthermore, when the Realized One awakens to the supreme perfect awakening, the earth shakes and rocks and trembles.