| Múlakvísl | |
| Subdivision Type1: | Country |
| Subdivision Name1: | Iceland |
| Subdivision Type2: | Region |
| Subdivision Name2: | Southern Region |
| Source1 Location: | Mýrdalsjökull |
| Source1 Coordinates: | 63.6306°N -19.8834°W |
| Mouth Location: | Between Vík í Mýrdal and Mýrdalssandur |
| Mouth Coordinates: | 63.4°N -18.8834°W |
| River System: | Múlakvísl |
The Múlakvísl (pronounced as /is/) is a river in the south of Iceland on the western side of Mýrdalssandur.
The river has a glacier flow which draws its water from the Mýrdalsjökull, mainly through the glacier tongue Kötlujökull. The river's floods are usually of gray-brown color, since it carries much sediment with it.[1]
At Selfjall, about 10km (10miles) east of the village Vík í Mýrdal, the Ring Road goes across a bridge over the Múlakvísl.
As increasing water levels of this river are an important indicator of Katla's upcoming volcanic eruptions, it is closely monitored.
A predecessor of the present bridge was demolished in 1955, during a jökulhlaup with 2,500 m3/s of water. A fissure formed on Katla in 1918 in the caldera of the volcano, and a kettle had formed upon the glacier. This showed volcanic activities under the glacier, which in turn initiated the jökulhlaup. However, there was no real outbreak in 1955.
On 9 July 2011, another jökulhlaup occurred, which was already anticipated hours and days before because of a series of quakes at up to 10km (10miles) depth in the Katla region.[2] [3] There was a small volcanic eruption under the glacier similar to 1955.[4] A jökulhlaup again destroyed the Ring Road bridge of the Múlakvísl, which was only 20 years old. A water level early warning system prompted the closing of the bridge and surrounding area, and no one was harmed.[5] By 11 July 2011, the tremor under Katla had calmed down again. On 15 July 2011, 1,500 people were transported via the Múlakvísl by means of special vehicles.[6] On 16 July, a temporary bridge was put into operation on the river.[7]