ISSN:
1365-246X
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Geosciences
Notes:
Time series of annual Mean Tidal Range (MTR) have been assembled from 13 ports around the British Isles and secular trends in MTR computed at each site. Trends vary between – 1.8 and 1.3 mm yr-1 depending on location. At many sites the values are significantly non-zero implying different trends in Mean High Waters (MHWs) and Mean Low Waters (MLWs). Such tidal behaviour has also been observed previously at stations along the adjacent European coastline, but is not well understood. At several places, the trends are sufficiently large that they should be taken into account in investigations of impacts of sea level change and in extreme level engineering studies. They also suggest that, in general, time series of MWH should not be used as proxies for series of Mean Sea Level (MSL). For most of the British Isles data, MTR secular trend is larger (more positive) for larger trend in local MSL, or water depth. Lerwick and Newlyn hourly heights have been used to show that the observed MTR trends at most locations must be due primarly to changes in the dominant M2 tidal constituent. A comparison is given of the British Isles findings to those from neighbouring countries; British, Irish, French, Belgian and perhaps southern Dutch MTR trends are found to be considerably less than those reported from the northern Netherlands and the German Bight.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-246X.1991.tb05704.x
