SEISMOLOGICAL INVESTIGATIONS 



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British Earthquake Inquiry. 

 The Organisation for the Collection of Seismic Data. 



Through the agency of an organisation developed since October 1935 to 

 collect detailed non-instrumental data about earthquakes disturbing the 

 British Isles, twenty-one undoubted earth tremors, thirteen doubtful 

 tremors, six land-subsidences and the seismic effects of three explosions 

 have been investigated to date, and material gathered for a catalogue of 

 quakes noticed between January i, 1916 and October i, 1935. 



At present the personnel of the organisation involves 287 permanent 

 voluntary reporters, recruited from forty-four counties in Great Britain 

 and the Irish Free State, and others in the Channel Islands, each of whom 

 notifies Dr. Dollar at Emmanuel College, Cambridge, immediately any 

 earth tremor disturbs the locality of the reporter concerned. Often these 

 reporters assist in the subsequent distribution and re-collection of question- 

 naires relating to effects of such a tremor. Their number has been in- 

 creased by 221 since July i, 1937, and additional help has been obtained 

 from officials in Government, University and private seismological ob- 

 servatories, the British Broadcasting Corporation, the Trinity House 

 Corporation, meteorological observatories and schools, as well as from the 

 Press Association and daily newspapers. 



The greatest part of the information is gathered by questionnaires, more 

 than 95 per cent, of which are dispatched from Emmanuel College. In June 

 1938 a third and abbreviated edition of the questionnaire was issued ; this 

 has proved of greater general utility than previous more elaborate editions. 



The Seismic Data gathered between July i, 1937, and June 30, 1938. 



Since July i, 1937 details have been collected about the following tremors 

 felt in the British Isles : 



Earthquakes : 

 July 9, 1937 

 July 20, 1937 

 September 8, 1937 

 December 4, 1937. 

 March 21, 1938 

 June II, 1938 



Subsidences and Mine-shakes 

 September 13, 1937 

 December 14, 1937 

 December 30, 1937 

 January i, 1938 



Explosions : 



November 20, 1937 

 December i, 1937 



Origins not Established : 

 November 21, 1937 

 December 6, 1937 

 January 29, 1938 . 

 April 13, 1938 

 April 20, 1938 

 June 18, 1938 



Walsall, Staffordshire. 



Perthshire. 



Horsham, Sussex. 



Comrie, Perthshire. 



South-East Edinburgh, Edinburgh. 



Ghent, Belgium. 



Cudworth, Yorkshire. 

 Nelson, Glamorganshire. 

 Norwich, Norfolk. 

 New Tredegar, Monmouthshire. 



Thrapston, Northamptonshire. 

 Waltham Abbey, Essex. 



Worthing, Sussex. 

 Tenby, Pembrokeshire. 

 Great Missenden, Buckinghamshire. 

 Stepney, London. 

 Golders Green, Middlesex. 

 Gilfach Goch, Glamorganshire. 

 (Now being investigated.) 



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