Naked Science Forum

On the Lighter Side => That CAN'T be true! => Topic started by: chris on 24/08/2018 17:54:15

Title: Does the Bosut River sometimes flow backwards?
Post by: chris on 24/08/2018 17:54:15

A caller to the Ask! the Naked Scientists phone-in programme today (https://www.thenakedscientists.com/podcasts/ask-naked-scientists/why-do-galaxies-spin) spoke of the Bosut River that, he said, apparently sometimes flows backwards.

This sounds fishy to me! Anyone heard of this?

Title: Re: Does the Bosut River sometimes flow backwards?
Post by: evan_au on 25/08/2018 01:53:46

Could they be talking about a "tidal bore"?

This is where the incoming tide overcomes the outflowing river, producing a wave that travels upriver.
Some people even go surfing on them!

See: https://en.wikipedia.org/wiki/Tidal_bore

Title: Re: Does the Bosut River sometimes flow backwards?
Post by: evan_au on 26/08/2018 00:03:49

As I understand it, the tidal bore does not actually reverse the flow of water in the river...

The tidal bore occurs in the lower section of the river, near the sea, and the speed of water in the river is pretty low, here.
The shape of the bay channels a peak incoming tide into a surge, which creates a wave.
The velocity of a wave exceeds the velocity of the water, so the wave propagates upriver, even though the water in the river continues to flow down to the sea.