What do we know about the 2023 Reykjanes eruption at Litli-Hrútur? Skip to content
reykjanes eruption 2023
Golli. The 2023 Reykjanes eruption

What do we know about the 2023 Reykjanes eruption at Litli-Hrútur?


Update: The Litli-Hrútur eruption ended on August 5, 2023. For information on the ongoing 2023 eruption near Grindavík, see this article.

An eruption began on the Reykjanes peninsula at 4:40 PM on July 10, 2023. It is the third eruption in three years at the site, and experts say the region has entered a period of increased volcanic activity that could last decades or even centuries. No inhabited areas or infrastructure are currently threatened by lava flow from the eruption, but gas pollution is a significant risk, both at the site and across Southwest Iceland and the Reykjavík capital area. A seprate article provides information on hiking to the eruption.

Uplift, earthquakes, eruption

In June, Iceland Review reported that steady uplift (land rise) had been measured on the Reykjanes peninsula since early April of this year. While the uplift of over 2 centimetres (around one inch) indicated that magma was collecting below the surface of the peninsula, there were still no indications if or when it would breach the surface. In early July, an earthquake swarm began on the peninsula, culminating in an M5.2 earthquake on the evening of July 9. The eruption began the following day, July 10, at 4:40 PM. This pattern – uplift followed by a period of strong earthquakes and then finally an eruption – mirrored the 2021 and 2022 eruptions at the same site.

Rannsóknarstofa í eldfjallafræði og náttúruvá, Háskóli Íslands.

Typical fissure eruption

The eruption is a fissure eruption that opened exactly where experts had predicted it would: between Litli-Hrútur and Mt. Keilir, just north of the 2021 and 2022 eruption sites. As is typical for fissure eruptions, its activity was most intense when it began and has decreased since. The eruption is relatively small but could last a long time. While the 2022 Reykjanes eruption lasted just short of three weeks, the 2021 eruption lasted around six months.

2023 Reykjanes eruption july 17
The Volcanology and Natural Hazard Institute of the University of Iceland. Landsat image from July 17 showing the lava fields created by the 2021, 2022 and 2023 eruptions, as well as burning moss on a 2 km long stretch east of the lava flow.

Figures from the first week

Between July 11-23, the eruption’s lava flow averaged 14.5 cubic metres per second, lowering to 13 cubic metres per second between July 13-17. Due to the margin of error in measurements, researchers say the difference is not significant. By July 17, the surface area of the lava frield created by the eruption was 0.83 square kilometres [0.32 sq mi], and its volume was 8.4 million cubic metres. The edge of the lava advanced 300-400 metres [980-1,300 ft] daily within the first week, with the distance being highly variable from day to day. The lava is around 10 metres thick on average but over 20 metres at its thickest.

All of these figures are quite similar to last year’s eruption in Meradalir but 2-3 times higher than the figures of the Geldingadalir eruption in 2021. So far, the current eruption is not threatening inhabited areas or infrastructure, though pollution from its gases as well as from wildfires set off by the lava are a significant risk for people at the site as well as further off.

Where to find more information

Iceland Review’s most up-to-date coverage of the eruption can all be found in one place.

Those who would like to know more can read about the geology of the Reykjanes peninsula or follow the University of Iceland Volcanology and Natural Hazard Group on Facebook for scientific updates in Icelandic and English.

Several live feeds of the eruption are available online, including here and here.

Information on hiking to the eruption.

This article will be updated regularly.

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