Supervolcano

9 September 1958, Edmonton, Alberta, Canada

31 March 1974, Wrexham, North Wales, UK

25 May 1957, Middlesbrough, Teeside, England, UK

1949, Columbus, Ohio, USA

1943

4 February 1962, London, Ontario, Canada

22 July 1960, Vancouver, British Columbia, Canada

13 January 1974, Terrace, British Columbia, Canada

8 December 1955, Penticton, British Columbia, Canada

17 February 1952, Southampton, England, UK

14 March 1955, Truro, Nova Scotia, Canada

1958, Glasgow, Strathclyde, Scotland, UK

1959, Innisfail, Alberta, Canada

20 January 1983, Toronto, Ontario, Canada