Mapping the Impacts of Iceland's Katla Subglacial Volcano on the Mýrdalsjökull Glacier

Abstract

Jökulhlaup is the Icelandic term for a sudden and substantial release of subglacial and/or proglacial water. The subglacial volcano Katla and its associated glacier Mýrdalsjökull, near Iceland's southern coast, have the potential to cause catastrophic jökulhlaups through geothermally induced melting and volcanic eruptions. The resulting jökulhlaups can cause destruction of property and detriment to human life. Water-filled ice depressions (termed ice cauldrons) are produced by enhanced geothermal heating/melting and are large enough to be identified through remote sensing; therefore, ice cauldrons can be used to infer geothermal hot-spot locations and melt rates. To assess the risk of surrounding communities and infrastructure, a map of geothermal hot spots, loss of glacial mass, and meltwater flow paths of the Mýrdalsjökull glacier were created and analysed. Using geospatial analysis, it was determined that three hazard zones – two towns, Alftaver (to the east) and Vik (to the south), as well as Iceland's main highway, Route 1 – are directly in the path of potential jökulhlaups originating from the Mýrdalsjökull-Katla complex. Future research should further constrain meltwater flow paths to determine potential flow discharge rates and areas that are at the greatest risk of flooding.