The Icelandic volcanoes have often caused problems in Europe because most of the time the smoke and ashes from the volcanic activities on the island move towards the European mainland. When there's volcanic activity on Iceland it is always expected that there will be pollution of the air and limited visibility, and one of the most affected things is the air travel which is shut down for that time period because the conditions are not right for the flights to be taking place. This volcanic activity appears as a result of the divergent tectonic boundary between the North American and European tectonic plate which are moving away from one another.