Kelduhverfi, the district at the head of Öxarfjörður between the mountains of Tjörnes and the river Jökulsá. Inland there are many fissures and chasms, difficult and dangerous to cross. At about the time of the volcanic activity by Leirhnjúkur in 1975 (see Road 848) there were repeated earthquakes in the Kelduhverfi district, very frequent and some quite severe in early 1976. There was another series of severe earthquakes in early 1978. The land is thought to be spreading and indeed, many new fissures and cracks have appeared and some older ones have got wider and deeper. These changes can be seen as far north as the sea. At the same time the land has subsided by at least a meter. The greatest changes are in the area between the farms Lindarbrekka and Hlíðargerði, most obviously by the farms Lyngás, Framnes and Hlíðargerði. Warm water has come up in many of the fissures. Down on the flat land called Vestur–Sandur a new lake has appeared, Skjálftavatn (“Quake Lake”). This has meant that the courses of many rivers have changed radically.