Hundreds of earthquakes every week are registered by the elaborate monitoring system run by the Iceland Met. Office. Most of them are very small (up to magnitude M2 or 2.5) and generally not felt. Larger quakes, from M3 to 4.5 even 5 do occur every year and still lager ones (M5-M7) have a recurrence period of years or up to many decades, even centuries, depending on the area. Currently, two types of earthquake series have hit the news in Iceland, both well known in our times. Typical rifting events (tectonic earthquakes) have occurred at the seabed SW and NE of Iceland as well as on land, for example on the Reykjanes Peninsula close to Reykjavík. They don´t cause general alarm and did not cause any damage. The other type is bouts of quakes in the centres (large volcanoes) of some of the volcanic systems, especially Katla and Bárðarbunga. The trembles have either origins at shallow depth (purely tectonic events – like subsidence in calderas) or much deeper down, due to magma movements.