occurred since then). This road, which encircles Iceland and was completed in 1974, has since been repaired. The 1996 jökulhlaup was caused by the eruption of the volcano, with peak flow estimated to be compared to the normal summer peak flow of . Net deposition of sediment was estimated to be . The main braided channels of are the Gígjukvísl and rivers, which incurred net gains of respectively during the 1996 jökulhlaup. In the Gígjukvísl there was massive sediment deposition of up to , which occurred closest to the terminus of the glacier. The erosional patterns of can be seen by looking at the centimetre-scale elevation differences measured with repeat-pass laser altimetry (LIDAR) flown in 1996 (pre-flood), 1997, and 2001. Of the overall deposition during the 1996 jökulhlaup, nearly half of the net gain had been eroded 4 years after the flood. These two rivers on the sandur display drastically different erosional patterns. The difference in sediment erosion can be attributed to the wide trench near the terminus where the Gígjukvísl flows, in contrast with the , which has braided flows directly onto the outwash plain. The Gígjukvísl river is where some of the highest level of sediment deposit occurred and also where the largest erosion happened afterward. This indicates that these massive jökulhlaup deposits may have a large geomorphic impact in the short term, but the net change on the surface relief could be minimal after a couple of years to a decade. The observed change of from a diffuse to a channelized distributary system where it has the most observed sediment deposit has a significant impact on the development of the fluvial succession in the proximal zone. However, in order to have sustained active accretion across the entire sandur there needs to be a diffuse, multipoint distribution system. The system of accumulation on , which is a product of glacier retreat, can be seen as multiple regions of differing channel patterns that distribute sediment across the plain in dynamic configurations. Fossil sandar Fossil sandar (i.e. no longer active) are found in areas which were formerly glaciated. An example would be the Usk Valley of South Wales where, towards the end of the last ice age, the receding Usk valley glacier left behind a series of recessional moraines and sandar deposits down-valley of them. Many of the sandar surfaces are still visible, albeit degraded over succeeding millennia. Extensive sandar