open the curtains

and take a look out the window if you want to know what the weather's like

River Fal 1: Fal / Mouth

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Articles in this series form part of a longer piece on the tidal section of the River Fal in Cornwall. In it I imagine what it would be like to start at low tide at the river mouth, travelling upriver to the highest tidal point at high tide, and returning back to the sea, by exploring the locations on and around the river and making my own ‘tidal journey’ inland and back out to sea. There are thirteen parts to the series. They can of course be read in order, but you don’t necessarily have to start with part 1, it being a cyclical journey there is no definitive start and end point. Each section can also be read as a stand-alone piece.

– Pendennis Point, western bank of the Fal Estuary (where?)

Waking to a Falmouth alarm call, the sound of a hundred seagulls breaks into my consciousness from the pre-dawn still. All night the full moon has been troubling my repose, and now it’s nearly day I’m exhausted but wider awake than anyone has the right to be at this dead hour.

Water is said to be the moon’s element, and the tide, ebbing and flowing round the clock, neap-ing and spring-ing to the lunar wax and wane, washes the moon’s watery influence into mankind’s perception visibly and tangibly, and altogether outside of human control.

So I go to look for the tide.

I find it out on the farthest point of the town at the end of the headland; and almost as far out as it could be. Being full moon the tide’s coming up to a spring low, emersing rocks and pools unused to fresh air save for this their once-monthly unveiling. Uncountable other-worldly organisms collectively take a deep breath in the intermission, sounding as though a bowl of briny Rice Krispies has been scattered in and on and among the crannied rocks. This is the soundtrack of the slack of the tide.

It’s getting lighter. What at first appeared to be islands looming up out of the sea expand through the dawn dim to headlands and peninsulas. This apparently fragmented coastline is actually a drowned river valley, or ria, formed at the end of the last ice age when sea levels rose. All in all the Fal Estuary is made up of waters from six main, and twenty eight smaller rivers; plus the tidal incomings and outgoings of the sea. A seagull’s eye view of the landscape, courtesy of Google Earth for the benefit of the land-bound among us, shows how the current topography echoes the dendritic pattern of the original river system of well over ten thousand years ago, which would have meandered towards a shoreline situated miles away from where I am currently standing.

As the light levels increase so do the colours start to bleed into the scene. The transition from day into night seems almost imperceptible when it’s happening, but after a minute or two you suddenly start to notice how much more you can see, how much greener the grass on the Roseland opposite, how much paler the sky. It’s the same with the turn of the tide, which in most places is so barely discernible that it might as well not be happening. It only enters the consciousness some considerable time after it’s happened, when it becomes obvious the water’s not as high up as it was half an hour ago, or the rock you were standing on right down on the shoreline is now being submerged by every incoming wave, where a little earlier your feet were high and dry. I have always wanted that moment, that watery ellipsis between the incoming and outgoing, to be more obvious, a noticeable pause where the water stops, brimful but sloshing slowly in one place like a full bath, just stepped-out of. In reality the moment the tide is as far out as it’s going to be it has already started coming in again.

Virtually all river estuaries are tidal, except those where hydrological outputs are significantly greater than the incoming tidal flow. The River Fal is tidal up to Sett Bridge between the villages of Ruan Lanihorne and Lamorran, approximately nine miles inland. Here at the mouth of the estuary there is a maximum tidal depth of 5.6m on a spring tide, whilst inland at its tidal limits this is more like 3.5m. Tides are caused by the combination of the effects of the gravitational pull of the sun and the moon and the rotation of the Earth, but are also influenced by the shape of the coastline, near-shore bathymetry, and sometimes weather conditions such as strong winds.

It feels slightly auspicious to be standing here at daybreak watching the turn of  the low tide, as though marking both in place and time the beginning of river, sea, solar day, and tidal lunar day. Because the moon takes twenty five hours not twenty four to orbit the earth a lunar day will always be slightly longer than the more familiar solar day. There are two full tidal cycles to every lunar day, so tide and time never quite catch up with one another, and neither are prepared to wait. I imagine floating on the tide as it fills up the estuary, and wonder what reply I’d get if I were to ask the tidal river to tell me about its day, as the water wends its way upriver from the mouth. Perhaps I can find out for myself if I work my own way upriver with the tide, tracing its twelve hour twenty five minute commute inland, and back home out to sea.

More on this? 

Jen Hadfield’s Daed-traa – an intertidal poem for the slack of the tide

plus this little animation and more links on the ins and outs of Tides

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Author: Merryn

open the curtains and take a look out the window if you want to know what the weather's like

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