I know less about tides than I realised

[opps]

I have spent the last few months walking over Hammersmith Bridge twice a day. On Saturday morning, I noticed the tide going out to the east, in the mean time the moon was visible in the west.

How does that work?

 

[gant]

 

[Pat ex]

I have spent the last few months walking over Hammersmith Bridge twice a day. On Saturday morning, I noticed the tide going out to the east, in the mean time the moon was visible in the west.

How does that work?

You don't get tides in the rivers as such, it's influenced by the tide (in the relevance to the Thames) by the tide in the Channel.
Low tide flows down the Channel to the SW,
Flood tide flows NE up the Channel.

At low tide in the Channel the Thames will flow out and at flood tide in the Channel the Thames will flow back up stream.

 

[opps]

Thanks @gant

I have no idea what the video of Bob Hope has to do with my question though.

 

[bernardgreen]

When the moon is pulling water in the oceans towards the west the sea level in the east ( English Channel ) is lowered and hence the Thames can flow east into the lowered English Channel

 

[opps]

You don't get tides in the rivers as such, it's influenced by the tide (in the relevance to the Thames) by the tide in the Channel.
Low tide flows down the Channel to the SW,
Flood tide flows NE up the Channel.

At low tide in the Channel the Thames will flow out and at flow tide in the Channel the Thames will flow back up stream.

That kind makes sense, but if the moon is still visible in the western sky, wouldn't it be attracting water from the
English Channel?

I often walk over the bridge at (approximately) the same time each day. The extent of visible mud banks can vary a lot.

 

[opps]

When the moon is pulling water in the oceans towards the west the sea level in the east ( English Channel ) is lowered and hence the Thames can flow east into the lowered English Channel

Ahh... I think I now see [not sea]. it has moved the larger volume of water, eg the Atlantic.

 

[noseall]

I have spent the last few months walking over Hammersmith Bridge twice a day. On Saturday morning, I noticed the tide going out to the east, in the mean time the moon was visible in the west.

How does that work?

It's pulling the sea up and away from the direction you are looking. Like your missus pulling the quilt off.

 

[Nige F]

Time and tide wait for no man

 

[fillyboy]

Basically the moon will have pulled the English channel and the water in Biscay westwards, so the North Sea will flow south toward the English channel and any river estuaries will empty into the North sea. The pull of the moon will shift large areas of water but it has to find it's way around any land masses. There are tidal maps showing the direction and speed of the water all around the coast as they are entirely predictable.

There is almost no tide in the Med because it's effectively landlocked other than a narrow channel to the Atlantic.

 

[Justin Passing]

Tides aren't quite that simple. Locally there are resonances, eg when the tide is high in the middle of the Channel it's low at the ends, and vv. There are 2 nodes where you get very little tide reach.
I think there's something similar in the North Sea.
Like a fat person walking, lots of wobbles...

I'm sure the boatists amongst us would know more.

 

[fillyboy]

Tides aren't quite that simple. Locally there are resonances, eg when the tide is high in the middle of the Channel it's low at the ends, and vv. There are 2 nodes where you get very little tide reach.
I think there's something similar in the North Sea.
Like a fat person walking, lots of wobbles...

I'm sure the boatists amongst us would know more.

I was trying to simplify it for him, I do know it's complex, very complex. I sailed for a little over ten years, South coast and North Wales and my knowledge of tides is probably still only patchy and limited to my local areas at the time.

 

[robinbanks]

There are two tides a day because the water is pulled into an oval shape; it doesn't all slump to the one side of the planet the moon is on, but instead bulges toward the moon and away from it on the opposite side of the planet. The sun has an effect on tides too, either strengthening or diminishing the moon's effect, and there's a delay between moon position and tide position, so you wouldn't necessarily say "the moon is overhead so the tide must be high"; it's much more involved. https://moon.nasa.gov/resources/444/tides/ has a good animation

 

[gant]

Thanks @gant

I have no idea what the video of Bob Hope has to do with my question though.

Now you've had some feed back is it a clearer?

 

[Pat ex]

Now you've had some feed back is it a clearer?

It'll still be muddy.
Don't start on pollution.