povratne brzice / reversing rapids

Naravni pojav povratnih brzic povzroča visoka razlika med plimo in oseko. Ob plimi teče morska voda pri izlivu v morje v rečno korito, ob oseki se brzice obrnejo in voda teče v znižano gladino morskega zaliva. Pojav je znan pri izlivu reke St. John v provinci New Brunswick v Kanadi. Pojav obratnega rečnega toka seže vse do glavnega mesta New Brunswicka, Frederictowna, ki leži 120 km v notranjosti.

glej: bibavica

The phenomenon of the Reversing Rapids is caused by the extreme amplitude of the tides. Well-known reversal rapids are on the St. John River at St. John, New Brunswick, Canada. The Bay of Fundy receives ocean tides directly like a funnel, squeezing the water as it travels up the bay. The incoming tide eventually collides with and overcomes the river flow, forcing it upstream in a process called resonance.

see: tide