Iceland sits in the North Atlantic Ocean between Europe and North America. It is one of the most volcanic places on Earth. The island formed from eruptions along the Mid-Atlantic Ridge, where two tectonic plates pull apart. In April 2010, a volcano with a very long name -- Eyjafjallajokull -- erupted beneath a glacier. When hot lava met the ice, it created an enormous explosion of fine ash. The ash rose over thirty thousand feet into the sky. Winds carried the ash cloud southeast across Europe. Volcanic ash is dangerous to airplanes. The tiny particles of glass and rock can melt inside jet engines. Airlines had no choice but to cancel flights. Over one hundred thousand flights were grounded in six days. About ten million travelers were stranded at airports across Europe. Trains and buses filled up as people searched for other ways to get home. The disruption cost airlines an estimated 1.7 billion dollars. The eruption showed how connected the modern world is. A natural event on a small island in the middle of the ocean affected daily life across an entire continent.