Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 43: Gaṅgā Descends to the Earth
Text 1.43.19

गगनाच्छङ्करशिरस्ततो धरणिमाश्रिता।
व्यसर्पत जलं तत्र तीव्रशब्दपुरस्कृतम्॥

gaganāc chaṅkara-śiras tato dharaṇim āśritā
vyasarpata
jalaṁ tatra tīvra-śabda-puraskṛtam

gaganāt = thus, from the sky; śaṅkara-śiraḥ = Gaṅgā reached Lord Śaṅkara’s head; tataḥ = and then; dharaṇim āśritā = the earth; vyasarpata = fell; jalam = Her water; tatra = on the earth; tīvra-śabda-puraskṛtam = making a terrible noise.

Thus, from the sky, Gaṅgā reached Lord Śaṅkara’s head and then the earth. Her water fell on the earth, making a terrible noise.

Sage Viśvāmitra answered Lord Rāma’s question on how Gaṅgā came to traverse through three pathways. Now he answers His other question on the activities associated with her, that is, activities carried out by her.

The first half of the verse describes the reason for the terrible noise.