Iceland has a high concentration of volcanoes. When Eyjafjallajökull erupted in April of 2010, it halted air travel for 10 million travelers in 20 different countries. The dispersion of the volcanic ash (see global map) caused the largest disruption of air travel since World War II. The airspace over northern Europe was affected for three weeks.
Many Icelanders attempted to help me, however, I still cannot pronounce this word that means “island-mountain-glacier.” I have the t-shirt and I’m working on it!