The salinity and temperature of the Irish Channel and the waters south of Ireland / by Donald J. Matthews.

  • Matthews, Donald John, 1873-1956.
Date:
1914
Catalogue details

Licence: In copyright

Credit: The salinity and temperature of the Irish Channel and the waters south of Ireland / by Donald J. Matthews. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    too high and the salinity too low. The most difficult section to draw on this account has been No. IX. Here the depth increases very rapidly seawards outside the 200-fathom line and it appears from the soundings made on the various cruises that the line of stations runs out along a submarine valley pushing up to the coast from the deeper water. Identical depths may be found here at the bottom of the valley at its shoreward end and on its slopes much further seawards ; but as will be shown later, there is strong reason to suppose that the isohalines and isotherms are tilted up the sides of the valley and so the salinity and temperature would not be the same at the two positions in spite of the agreement of the depths. The Plymouth and Liverpool Observations. In order to make the report as complete as possible use has been made of the results obtained in connection with the International Fishery Investigations by the Marine Biological Association at Plymouth and by the Liverpool Marine Bio- logical Committee. The Plymouth observations consist of five stations (E on the charts) (Plates XI to XV), on the western side of the Irish Channel and south of the latitude of the Smalls Light, and of a series of surface observations at the Cardigan Bay and Seven Stones Lightships, of which the former is now removed. Of these stations, E6 has been worked on all quarterly cruises except one, from the beginning of the investigations in February 1903 to November 1909, the last cruise before the work was transferred to the Board of Agriculture and Fisheries. Stations E26 to E30 have been worked twice in February and three times in May, August, and November; E30 has since been adopted as an Irish Station so that in some cases there are four sets of observations from this position. In the Irish Sea the Liverpool Marine Biological Committee has a line of stations running westwards from Morecambe Bay, along the fifty-fourth parallel, to the Isle of Man, and then turn- ing southwards a short distance to the east of the easterly Irish stations. There are here sets of observations for each of the quarterly cruises, for the years 1907 to 1910 inclusive ; on some cruises only surface observations have been made, and in order to calculate the mean bottom salinity and temperature the missing values have been interpolated by calculation of the difference between the surface and bottom for the dates when observations at both are available. There is therefore some uncertainty as to the true bottom conditions, but the char- acter of the water changes so rapidly as we cross from the shal- lows of Liverpool Bay to the deep water westward of the meridian of the Isle of Man that the error in the charts is negligible. It will be seen that in some cases the isohaline or isotherm running through these Liverpool Stations is shown by a broken line, indicating some doubt; this is not intended to convey that the observations here are doubtful, but that they are not such that the course of any one isohaline can be accurately traced.