No, do not be frightened! There was no earthquake here on Madeira. On the contrary of the Azores Islands … the archipelago of Madeira is very stable. Even when you consider that the whole archipelago (Madeira, Porto Santo and Desertas) emerged from the sea thanks to large eruptions and volcano activities 700,000 years ago.
Below you will see an image of the seismic activity of the mainland (Portugal) and Madeira (left corner below) of the last month.
The next image is of the seismic activity of AÃ§ores the last month:
For more seismologic information go to The Portuguese Meteorological Institute
Of course … this does not mean we will never have a quake …. you never know when Mother Nature will a bad day ….