Intraplate seismicity and seismic risk in the Atlantic Ocean based on teleseismically observed earthquakes

This report is concerned with the seismic risk within the intraplate regions of the Atlantic Ocean and forms part of a programme to assess the suitability of the ocean floor for the disposal of high-level radioactive waste. Earthquakes with magnitude up to (Ms) 7.2 have been observed with epicentres within the intraplate region. Observations of oceanic intraplate earthquakes worldwide suggest an upper limit of (Ms) 7.3 on the magnitude of these events. Apart from an active zone to the E and NE of the Caribbean, seismicity appears uniformly distributed but with the observed level of activity in the North Atlantic twice that in the south. (author)