Yesterday lunchtime at 1pm, the National Geographic Institute (IGN) registered an earth tremor which reached 5.7 on the Richter scale, in the sea off the west coast of El Hierro. The quake occurred at a depth of 15 kilometres and was also noticed by the public. A total of six tremors of between 2.3 and 5.7 on the Richter scale occurred during the same day.