Tidal Bore
Context: Recently, a thunderous pororoca tidal bore wave was created on the Mearim River in the Amazon jungle, near the northern Brazilian city of Arari.
Important Pointers:
► Definition: A tidal bore is a sudden and strong surge of tidal water that travels upstream in a river or narrow bay against the direction of the river current due to an incoming high tide.
► Formation Conditions: • Large tidal range (typically more than 6 meters) • Funnel-shaped river mouth or estuary • Shallow and narrowing river channel • Presence of an estuary that amplifies the tidal wave
► Geographical Occurrence: • A rare phenomenon, observed in a few places globally • India: Hooghly River (West Bengal) – most notable example • World: Qiantang River (China), Amazon River (Pororoca) in Brazil, Severn River (UK)
► Impact: • Affects river navigation and port operations • Can cause erosion of riverbanks and damage to structures • Sometimes attracts tourists and surfers (e.g., Pororoca in Brazil)