A jökulhlaup (Icelandic pronunciation: [ˈjœːkʏlˌl̥œip] pronunciation (last word in a list) (help·info)) (literally "glacial run") is a type of glacial outburst flood.[1] It is an Icelandic term that has been adopted in glaciological terminology in many languages. It originally referred to the well-known subglacial outburst floods from Vatnajökull, Iceland, which are triggered by geothermal heating and occasionally by a volcanic subglacial eruption, but it is now used to describe any large and abrupt release of water from a subglacial or proglacial lake/reservoir.