These topics relate to the tidal and sea level research carried out at the National Oceanography Centre in Liverpool.
The alternating rise and fall of the sea surface are due mainly to the gravitational attraction of the moon and sun on the rotating earth – Read more →
Tidal predictions were first carried out in 1924 at Bidston Observatory (University of Liverpool Tidal Institute), initially by hand and then by early tide predicting machines – Read more →
Tide clocks and watches are practical ways of indicating the state of the tide, in addition to consulting local tide tables – Read more →
In most tidal rivers the change from ebb to flood is gradual: the ebb current downstream slows, there is a period of slack water, then slowly the flood tide starts flowing upstream. In a few rivers, the behaviour is remarkably different and the onset of the flood tide is marked by a distinct, sometimes very vigorous wave – a bore – Read more →
The River Dee, between Wirral and North Wales, is unusual in that comparatively little water occupies so large a basin. A recent theory is that the estuary was not formed by water, but by ice being pushed southwards by the pressure of an icecap over the Irish Sea – Read more →
The River Mersey begins at the confluence of the River Tame and River Goyt, and flows 70 miles to the Irish Sea; its estuary has the second highest tidal range in the UK – Read more →
Answers to a selection of questions asked by the public.
Find out about 'mean sea level', 'altitude above sea level', global sea level rise, and how measurements by GPS (Global Positioning System) and tide gauges help us to understand sea level change – Read more →