Monday, 15 September 2014

Magnitude 4.7 Earthquake in Dalarna County, Sweden.

The United States Geological Survey recorded a Magnitude 4.7 Earthquake at a depth of 14.3 km in Dalarna County, Middle Sweden, slightly before 3.10 pm local time (slightly before 1.10 pm GMT) on Monday 15 September 2014. This is a large event for Scandinavia, but not particularly dangerous, and there are no reports of any damage or injuries, but people have reported feeling the quake across much of Sweden and in parts of Norway and Finland.

The approximate location of the 15 September 2014 Dalarna County Earthquake. Google Maps.

Earthquakes are rare in Sweden, and the waters between them, and those that do occur tend to be small, which makes the causes hard to determine. The entire of Europe is being pushed eastward by the expansion of the Atlantic Ocean and northward by the impact of Africa from the south, though these are remote from the Kattegat. There are lesser areas of expansion beneath the North Sea and Rhine Valley, both of which will presumably have some effect on southern Scandinavia. 

Finally their is glacial rebound; until about 10 000 years ago much of northern Europe was covered by a thick layer of ice. This pushed the rocks of the lithosphere down into the underlying mantle, and now that the ice is gone these rocks are springing back up, albeit very slowly, a process which is not smooth as rocks  tend to stick to one-another, and which therefore causes the occasional small Earth tremor.

(Top) Simplified diagram showing principle of glacial rebound. (Bottom) The extent of glaciation in Europe at the last glacial maximum. Wikipedia.

See also...

Lake Vättern is the second largest lake in Sweden. It lies in the south of the country, and is 135 km long and 31 km in width at its widest...

The Kattegat Sea separates Denmark from Sweden, north of the Islands of the Straits of Denmark. On Monday 6 August 2012, slightly before 5 am local time (slightly before 3 am GMT), an Earthquake took place 5.8 km beneath this sea, according to the...

On Thursday 24 May 2012, slightly after 10.45 pm, GMT, the United States Geological Survey recorded an Earthquake on the Mid-Atlantic Ridge, roughly 600 km north of Tromsø, at a depth of 8.8 km, and measuring 6.2 on the Richter Scale. Since this time...

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