Shloka 5.1.18
समुद्रलङ्घनारम्भः — Commencement of the Ocean-Crossing
स महासत्त्वसन्नादः शैलपीडानिमित्तजः।पृथिवीं पूरयामास दिशश्चोपवनानि च।।।।
sa mahāsattvasannādaḥ śailapīḍānimittajaḥ | pṛthivīṃ pūrayāmāsa diśaścopavanāni ca ||
That loud clamor of the great creatures, born from the crushing of the mountain, filled the earth, the directions, and the groves.
Due to the crushing of the mountain, a loud noise of the various creatures shot up filling the earth in all directions and groves around.
The noise was caused by the distress of the great creatures (mahasattvas) resulting from the pressure exerted on the mountain by Hanuman's leap.
It signifies the immense physical force generated by Hanuman, which was sufficient to crush the mountain (shaila) and disturb its ecosystem, illustrating his extraordinary strength.