A powerful 6.1 magnitude earthquake shook the Mediterranean Sea off the coast of Morocco on January 25, 2016.
It was then followed by a swarm of 6 moderately strong aftershocks ranging from 4.6 to 5.3 in magnitude. Strange roaring noises were heard. Pretty rare over there, no?
As shown on the map all epicenters are close to each others off the city of Al Hoceima, Morocco. The strong M6.1 tremor occurred at 4:22 am (UTC). The swarm began at 4:30 am (UTC) with a M5.0 earthquake followed by a M5.3 at 4:34 am (UTC), M4.6 at 5:03 am (UTC), M5.1 6:10 am (UTC), M5.3 at 6:54 am (UTC) and M4.7 at 8:25 am (UTC).
That demonstrates the rarity of this swarm.
The earthquake was felt in northern Morocco, in the south of Spain, in the north-west of Algeria, as well as in the south of Portugal.
People also heard strange roaring noises and booms, the so-called earthquake booms.