Most of us are able to imagine to destructive side to volcanoes – loss of life, damage to property and disruption to transport. The Icelandic volcano that erupted in 2010 brought air traffic in Western Europe to a stand-still and resulted in the near bankruptcy of several airlines around Europe as they were not permitted to fly. The huge ash cloud that this volcano emitted travelled across Europe at a height of about 11000 metres, which was hazardous to jet engined aircraft. However, volcanoes also bring benefits. In Iceland, for example, volcanic activity heats water close to the surface which is then used to generate geothermal energy. The positives and negatives of volcanoes are discussed in the physical geography page, where notes are provided on this topic.