Iceland Volcano Update: City Gas Warning, Lava Bed Map as Tongue Flows West

The Icelandic Meteorological Office has warned that gas being expelled from a lava fissure on the nation's Reykjanes Peninsula could be carried on westerly winds over the nearby capital, Reykjavík, as volcanic activity continues to decrease following Monday's eruption.

In an update on Wednesday, officials said that lava was flowing to the east of the fissure but noted that a tongue of lava was also flowing westward, to the north of Stóra-Scógsfell mountain. A geothermal power plant at Svartsengi sits to the west of the eruption zone—but is protected by higher terrain and earth walls—while the coastal town of Grindavik sits to the southwest of the fissure.

As of Tuesday evening, the lava had spread across an estimated area of 3.7 square kilometers (1.4 square miles). A map produced by the Icelandic Met Office, based on satellite imagery, shows where lava has flowed across the Reykjanes Peninsula, as well as the two active vents.

The molten rock is currently flowing into uninhabited land and, at its southwesterly tip, is around 1.7 miles from Grindavik, which is also protected with earth barriers and was evacuated prior to the eruption.

The Icelandic Met Office said the intensity of the eruption "continues to decrease," as has the seismic activity that preceded and accompanied the eruption, as magma propagated into a weak point in the Earth's crust to form a vertical dike.

The number of vents along the fissure had fallen from five to three by Tuesday evening, and it said on Wednesday that it had since gone down to two.

However, both officials and volcanologists have warned that further eruption sites along the fissure could yet open up. The vertical dike is thought to be fed by a horizontal intrusion under Svartsengi, which had been inflating since November 10 before falling by a fifth following the eruption—but still contains a large amount of magma.

While the lava fountains were estimated to reach as high as 656 feet into the air during the initial phase of the eruption, as of Tuesday, they were measured at around 98 feet.

The Icelandic Met Office assessed that the hazards in the region had "increased significantly" since the eruption occurred and that there remained an increased chance of further eruptions on the Reykjanes Peninsula. It saw the greatest risk along the 9.3-mile path of the dike, with elevated risks to Grindavik and Svartsengi.

Haraldur Sigurdsson, an emeritus professor of geophysics at the University of Rhode Island and a leading Icelandic volcanologist, told Newsweek on Tuesday that how quickly the eruption had slowed suggested it could be over by the end of the month.

He said the lava "is spreading over an uninhabited region and does not threaten lives or property at this time" and that residents of Grindavik "should be allowed home for Christmas"—though other experts said it was "too soon to say" how long the threat of eruption might last.