The silly thing about volcanic eruptions is that individuals (broadly speaking) listen when (1) a volcano that hasn’t erupted recently erupts; (2) a volcano come of us erupts and (3) a brand recent eruption begins where a illustrious outdated eruption came about. The media descends and also you should per chance well per chance doubtless also find volcanologists (esteem me!) being interviewed about the ramifications of this, that and the different volcanic thing.
That is great (initially), attributable to awareness of the volcanic exercise on Earth arrangement that individuals might well very well be less at risk of think every eruption arrangement world doom and that maybe they’re going to settle to be ready in the occasion that they live come a volcano.
Case in point: Iceland. The eruptions come Grindavík during the final six months hang continued to threaten the town, the Blue Lagoon and the geothermal plant on the Reykjanes Peninsula. On the different hand, with every recent salvo, the glory it will get from the world media goes down. “Or no longer it is appropriate one more eruption in Iceland” seems to be to be the perspective.
What’s Up (and No longer Up) Correct Now?
Basically the most recent eruption come Grindavík began on March 16 and if it used to be esteem the outdated ones, we’re going to must hang anticipated about a days of eruption that created lava fountaining, some lava flows after which a behind petering out of the exercise. But, right here we are, ~10 days later and right here’s what it seems esteem authorized now:
The cone fashioned during the present Sundhnúksgíga eruption come Grindavík in Iceland seen on March 27, 2024. Credit: MBL.is webcam quiet.
That is … diversified! Instead of the an identical pattern of inflation on the land floor, a brand recent (and transient) eruption and repeat, this eruption north of the metropolis has been going stable for days. What’s changed?
Maybe no longer distinguished. The Icelandic Meteorological Administrative center studies that the rates of lava coming out of the bottom at Sundhnúksgíga will no longer be too diversified than past eruptions in the train. On the different hand, what has changed is that magma rising up into the crust doesn’t seem like stalling on the technique to the floor. The IMO has famed that there might be dinky to no earthquake exercise in the dike or its vicinity and uplift in the train round Svartsengi has been very slight since the eruption began on March 16.
To paraphrase the IMO’s evaluate, which capability that that less magma is accumulating and is instead “flowing more straight out of the reservoir thru the eruptive fissures”. This style we are getting a relentless spin alongside with the poke of liquid rock from its sources tens of kilometers down to the floor.
Why it has changed is a more subtle to pinpoint. Maybe the conduits that bring magma to the floor hang develop into “primed” by outdated eruptions so there are no longer impediments to it making a straight shot. Maybe the feature that the magma is using to succeed in the floor gives less resistance to eruption. Maybe none of these things.
The line of eruptive vents alongside the fissure at Sundhnúksgíga that fashioned starting March 16, 2024. This photo used to be taken on March 20, 2024. Credit: IMO.
Now, instead of a fissure erupting lava flows now we hang a series of cones (above) that are building as the lava spurts out of the bottom esteem a hose. The debris from this spattering piles up at some point of the vent to make what might well per chance indirectly develop into cinder cone that line up alongside what used to be the fissure. If you look for at a topographic scheme of the Reykjanes Peninsula, you should per chance well per chance doubtless also find a total bunch examples of these clusters associated to eruptions appropriate esteem these in the past.
Fresh Eruption by the Numbers
Mapping of the present exercise has lava flows as thick as 16 meters (50 feet) come the vents at Sundhnúkar. Since this eruption began on March 16, the IMO estimates the eruption rate at ~14.5 cubic meters (~500 cubic feet) per second — a rate that is authorized in line with other eruptions in this sequence and earlier eruptions at Fagradalsfjall since 2021. This recent eruption has dumped over 20 million cubic meters (700 million cubic feet) of basaltic lava onto the floor … that is roughly 350 great oil tanker ships!
The hazard for folks round Grindavík hasn’t changed that distinguished. The lava flows might well per chance murder properties and infrastructure. On the different hand, Iceland has originate lava spin alongside with the poke levees to relieve divert the flows from the metropolis as finest as they’ll (as soon as in a while using the recent lava itself to originate the levees!) Maps of the lava flows from March 20-26 explain how they’ve mostly been diverted by the walls and levees built to the north and west of Grindavík.
Lava spin alongside with the poke scheme of the present exercise come Grindavík in Iceland showing the thickness of lava measured on March 20, 2024. Credit: IMO.
On the different hand, with the constant eruption of sulfur-rich basaltic lava from these vents, the volcanic gasoline hazard has increased. Sulfur and water make sulfuric acid, so when the fumes from the eruption blow into a populated train, breathing can develop into … sinful. It might well per chance be downright uncertain to of us with respiratory situations. The IMO maps where the volcanic gases are headed in line with the climate to present of us a “heads up” for capability volcanic fog (vog) or other breathing hazards.
It might well per chance be vital to be mindful that an eruption might well per chance has drifted from the headlines, nonetheless as exercise esteem this continues, of us’s lives are quiet highly disrupted. The eruption to this point has no longer broken distinguished of Grindavík, nonetheless the volcanic gases and incessant threat of original exercise has doubtless made life a sing. It’s easy to think of volcanic failures as points in time, nonetheless eruptions esteem these are better regarded as marathons, no longer sprints.