According to information provided by the National Geographic Institute, a magnitude 1.9 earthquake occurred at 14.26 hours off the coast of Torrevieja and Orihuela. The epicentre of the quake was located in the sea, 5 km deep.
This small earthquake is one of many that occur annually in the Vega Baja, an area of high seismic risk. Many go unnoticed but some of them are felt and heard as in this case.
Generally speaking, earthquakes off shore that are deep down are not felt at all but this one was quite shallow.