Vatnaöldur

{{Infobox eruption | name = Vatnaöldur | image = Landmannalaugar Iceland 2005 3.JPG | image_size = | caption = Vatnaöldur fissure associated features are in the far distance over the river in this picture from Bláhnúkur towards the north-east | date = 877 ± 2 | start_date = | start_time = | end_date = | end_time = | volcano = Bárðarbunga | type = Fissure vents | location = | coordinates = | area = | volume = | VEI = 4 | map = {{maplink|frame=yes|frame-align=center|frame-width=260|frame-height=220|frame-long=-18.75|frame-lat=64.18|zoom=7|raw=[,,,,,,,{ "type": "Feature", "properties": { "marker-size": "small", "marker-color": "#ff0000", "marker-symbol": "volcano", "title": "Vatnaöldur" }, "geometry": {"type": "Point", "coordinates":[-18.7525, 64.181111]} }] |text=Selected geological features near Vatnaöldur (red marker). }} | map_size = | map_caption = | map_image = | impact = }} Vatnaöldur () is the name of a series of craters in the Suðurland region of Iceland. They are located in the Highlands of Iceland, north–west of the Veiðivötn and north–east of Landmannalaugar, within the municipality of Rangárþing ytra. It is part of the Eastern volcanic zone (EVZ).

The craters were formed during a series of eruptions associated with a basaltic dyke intrusion from the volcanic system of Bárðarbunga around the year 877. These eruptions, like those of the neighbouring Veiðivötn, were from about (or ) long volcanic fissures within the area of a lake. The mainly explosive eruptions emitted of tholeiite basalt. There was an associated rhyolite eruption near Torfajökull triggered by the intrusion. The associated tephra layer is called the Settlement layer, and covers more than half of Iceland’s land surface.