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

History of the Seismological Observatories in the British Isles 485A Milne-Shaw seismograph was installed in 1914 (no. 1) and an improved versionof the same instrument replaced it in 1924 (no. 32). The static magnification ofthese instruments was 150. A second component was added in 1934. The stationceased recording in 1957.3.2. DurhamDurham University Seismological Observatory was set up in 1930, with the installationof a Milne-Shaw (N-S component) seismograph which started operationin January, 1931. A second Milne-Shaw (EW component) was added in January1938. The station ceased operation in July, 1939 and restarted in January, 1946.A vault was constructed in 1955 and a Wilson-Lamison vertical instrument wasinstalled, together with the two Milne-Shaw seismographs, in October 1956. Thestation was still in operation in 1985.3.3. Dyce/AberdeenThe first seismological observatory to be established in the Aberdeen area was atParkhill House, Dyce. This observatory was founded by J. E. Crombie. Recordingwas begun in 1914 using two Mainka horizontal seismographs and an Agamennoneinstrument. The Mainkas had a free period of 10 seconds and a static magnificationof 150. In 1918 a Milne-Shaw seismograph was added. All these instrumentsran until Crombie’s death in August 1932, when the Agamennone and one of theMainkas was donated to the Science Museum. The Milne-Shaw, which was donatedto Aberdeen University, was set up for testing in the basement of King’s College,Aberdeen in 1932, and eventually became the EW component of the Aberdeen stationwhich operated continuously from December 1936 to June 1967. A Milne-ShawN-S component was added in 1938. The Milne-Shaw instruments ceased recordingin 1966 (Neilson, 1981).3.4. The Royal Observatory, EdinburghThe first instrument to operate in Edinburgh was a Darwin bifilar pendulum,which was originally installed in the Calton Hill Observatory in March 1894 andmoved to the Royal Observatory, Blackford Hill, in October 1895. Photographicregistration apparatus was added in August 1896 and a second pendulum was purchasedin May 1898. In 1900 a Milne pendulum was installed. New recording drumswere added in 1909, which gave a faster paper speed of 240 mm per hour.A Milne-Shaw seismograph (no. 3), formerly at Eskdalemuir, was moved toEdinburgh and began recording on July 4, 1919. The E-W component had a staticmagnification of 250.After World War 11, E. Tillotson took over the reading of the Edinburgh seismograms.During the period 1939-1940 various interruptions to recordings occurredowing to defects of the drum drive and to quarry blasting.The Milne-Shaw instrument ceased operation in April 1962, when it was transferredto the Royal Scottish Museum.