Historical Seismograms - Evidence from the AD 2000 Izu Islands ...

486 G. Neilson and P. W. Burton9.5. EskdalemuirThe first instruments at Eskdalemuir were a Milne twin boom instrument whichbegan operating in 1908 shortly after the observatory opened, and a Wiechert wasinstalled in 1909. The installation of an Omori followed in 1910. In the sameyear Professor Schuster of Manchester University presented the observatory withtwo Galitzin horizontal seismographs, which were set up as a N-S and an E-Wcomponent. Two years later he donated a vertical instrument, and these threeinstruments remained for many years the only three component set of seismographsin operation in the United Kingdom. The instruments were made in St. Petersburgby H. Masing and their installation was supervised by Prince Galitzin. Recordingwith the Galitzins began in July 1910 (Jacobs, 1964). In July 1915 a Milne-Shawinstrument was installed for comparison with the Galitzin. This instrument wastransferred to the Royal Observatory, Edinburgh, in June 1919. The Omori wasdonated to the Science Museum in 1921 and the Galitzins were transferred to KewObservatory in 1925 (Scrase, 1969).After 1925 seismology studies ceased at Eskdalemuir until the World Wide StandardStation was installed in 1963 and began continuous operation in 1964.3.6. Jersey, Channel IslandsAfter the plans fell through to move one of J. E. Crombie’s Mainka instrumentsfrom Dyce Observatory to St. Louis Observatory, St. Helier, Jersey, M. E. Rothkof the Institut de Physique du Globe, Strasbourg, lent an instrument of the sametype to St. Louis Observatory. This seismograph was set up in Jersey in 1935. Ithas a mass of 450 kg, a static magnification of 140, a free period of 13.7 seconds,and a damping ratio of 2.9.The station began operating in June 1936 and recording was interrupted in 1940by the German occupation of the Channel Islands. Recording recommenced in June1946 and the station is still in operation.3.7. KewInitially the body responsible for seismology at Kew Observatory was the NationalPhysical Laboratory. Later the responsible body became the MeterologicalOffice, which was also responsible for seismology at Eskdalemuir Observatory. Thefirst seismograph installed at Kew was a Milne seismograph, which began operationin 1898. This instrument, the ninth to be manufactured, was set up as an E Wcomponent.Operation of the Milne instrument was discontinued in 1925. In the same year,the Galitzin three components were transferred from Eskdalemuir to Kew and wereinstalled in the basement of the main building. This location was not satisfactory,because the instruments suffered severely from strong, wind-induced noise (Lee,1939).Two Wood- Anderson torsion seismographs were constructed at the Observatoryin 1933 and 1935 and put into operation. The year 1936 saw the construction ofa new building designed to house all the seismographs and in February 1937 theWood-Anderson instruments were moved into it, followed by the Galitzin horizon-