The fissure vents from the 1783 Laki eruption.
Alexandra Witze & Jeff KanipeIsland on Fire, by Alexandra Witze and Jeff Kanipe, was recently released in the U.S. It is an excellent book that tells the story of the 1783 eruption of the Laki fissures in Iceland, an event that not only have a profound impact on Iceland itself, but also the world for years (decades?) afterwards. The Laki fissures were a series of very large lava flows that covered the landscape with over 14 cubic kilometers of lava and over 120 megatons of sulfur dioxide (compare that to Pinatubo in 199 that released only 20 megatons.)
What is most gripping about Island on Fire is the narrative told from records of the local people living near the Laki fissures, especially Jón Steingrímsson. Without the look at the personal trials and tribulations that the people of Iceland felt before, during and after the eruption, it is merely a story of a bunch of molten rock spilling onto the Earth's surface. However, the Laki eruption was much more than that for the people of Iceland, much like the Dust Bowl was much more than a dry period for the people of the Midwest. Witze and Kanipe capture that drama and encapsulate it an appropriate (and accurate) geologic and volcanologic context that makes you really understand what it might have been like to live through such an event. Eruptions readers had a chance to send in some questions for the authors of the book, so without further ado, here are the answers. Enjoy! Karl Kopp: Which was the largest eruption in Iceland since men (and of course women) lived there? The eruption of Laki or the Eldgja eruption of 934? Were there even larger eruptions prior to these?Witze and Kanipe: The Eldgjá eruption that began in the tenth century was even bigger than Laki 1783: it lasted for maybe six years rather than eight months, and erupted more than 18 cubic kilometers of lava compared to Laki’s 14.7. It must have been devastating to Iceland’s early settlers. It was also the most polluting eruption in recent history, pumping out twice as much sulfur dioxide as either Laki 1783 or Tambora 1815. There just isn’t very much known about Eldgjá, though that may soon change: Thor Thordarson, who did the seminal work on mapping the Laki lava flows, has started a project with Will Moreland and others to better understand exactly what happened during Eldgjá. (Incidentally, there have been a couple of papers arguing that the Eldgjá eruption began in the year 939 and not 934. See for instance this 2013 publication that looked at the annals of Irish monks.) If you want to look instead at big explosive rhyolitic eruptions from a single mountain (as opposed to the lava-oozing fissures), the largest in Iceland since settlement was Öraefajökull in southeastern Iceland, in 1362. A modern parallel to that might be the 1991 eruption of Mount Pintabubo in the Philippines.
The road to Laki.
Alexandra Witze & Jeff KanipeSnailofFail: Firstly, how did the rate of lava flow [for Laki] compare to that of the current eruption at Holuhraun?Witze and Kanipe: The new lava flow at Holuhraun is the largest in Iceland since 1783, but it’s only a fraction of what Laki put out. You can see a map comparing the erupted lava so far here (it dates back to November, but it’s still generally accurate at the scales we’re talking about). SnailofFail: How come the current eruption hasn't been nearly as destructive as the Laki eruption even though they are both large fissure eruptions?Witze and Kanipe: See above: the amount of lava coming from the Holuhraun fissure is nowhere close to what Laki put out. The same is true for the sulfur dioxide coming from Holuhraun: although it emits some 35,000 tons of SO2 daily (levels that threaten scientists working at the site, and sometimes Icelanders farther away), that’s still only about a tenth of Laki’s sulfur production rate. The Holuhraun eruption is also happening in a very remote part of the country. There are no towns being threatened by the lava flow, as there were with Laki in 1783. SnailofFail: Finally do you believe the current eruption will ever come close to equaling the volume of lava produced by Laki?Witze and Kanipe: The current eruption would have to up its game dramatically to get anywhere close. So far there’s been little indication that might happen — but you never know! Emulsies: I enjoyed your book so much that I have now lent it to a cousin. But I had one burning question about the figure showing the level of the Nile supposedly reacting to Laki atmospheric impact (I think page 141 if I remember correctly). However, looking carefully at the figure it seems that Laki occurs AFTER the biggest change in the Nile level. So that suggests that, if there is any correlation, it is the other way round (which is very very unlikely'. Just wishful thinking in interpreting the Nile date or an error in the axis of the figure or a different explanation?Witze and Kanipe: You’re absolutely right — the Nile level drops in 1782, the year before the Laki eruption. The paper from which that figure comes (Oman et al., 2006, available via open access here) acknowledges that by simply saying that a low-flow event was reported the year before Laki, as well as in 1783 and 1784. “Those three years had the lowest river levels of the surrounding 50 years,” the authors write. They go on to make a statistical argument that there is an incredibly small chance that the 1783 and 1784 low river levels were due to natural variability and not the Laki eruption. It’s not incredibly satisfying from a layperson’s point of view. Kver: Has anyone tried to explain the mechanism in Iceland that makes so many of the melt's rich in Florine?Witze and Kanipe: It probably traces back to primitive geochemistry of the mantle plume, or hot jet of molten rock, that is thought to rise beneath Iceland. Martijn Keizer: Laki is mostly infamous for causing a humanitarian crisis in Iceland and (to a lesser extent) in Europe. With modern developments in medicine and international aid, you could argue that these effects would be less. However, nowadays there is a much bigger population density, which might counteract this. If a Laki-style eruption would occur today, do you think the humanitarian problems would be less or more severe, and by how much?Witze and Kanipe: We think a Laki-style eruption would cause more devastation today than in 1783, simply because of the sheer amount of people who would be involved and the interconnected nature of modern society. Look at how European business was devastated in the spring of 2010 by planes being grounded during the Eyjafjallajökull eruption, which was only a relative pipsqueak. The UK Cabinet Office is studying scenarios to better understand the economic and social consequences of a gas-rich eruption like Laki 1783. The emergency preparedness experts there are taking the threat of a Laki-style eruption quite seriously.
Thor Thordarson having a smoke atop ash layers from another Icelandic eruption.
Alexandra Witze & Jeff Kanipejduexf: How was estimated the height of the eruptive column of Laki? Witnesses or empirical calculations? How high was this eruptive column?Witze and Kanipe: Laki’s ash plume rose 10 to 13 kilometers high, an estimate based on both eyewitness accounts and model calculations. jduexf: How fast was eliminated the sulfur dioxide in the atmosphere? Was the sulfur dioxide in low (high) atmosphere responsible for the transient climatic change?Witze and Kanipe: Some 80 percent of the sulfur dioxide erupted by Laki would have been lofted high enough in the atmosphere to spread long distances. Sulfur in the lower part of the atmosphere would have been cleared out in about a year, while the particles higher up would have lasted a bit longer, maybe up to several years. It would have been these higher-elevation sulfur particles that contributed the most to short-term climate change. jduexf: Is the current eruption likely to have any effects on climate?Witze and Kanipe: Not the way it’s going. The gas isn’t being lofted high enough into the atmosphere to be carried long distances and have a climatic effect. Me: How is the Laki eruption held in the minds of Icelanders? Is there an American equivalent for a natural disaster, culturally-speaking?Witze and Kanipe: Icelanders learn about the Laki eruption and the resulting ‘mist hardships’ in school, and the non-scientists we talked to in Iceland all knew about it. There are lots of potential American analogues, though it’s a bit more complex because the US is such a big country and events that radically re-shape one region can barely register a cultural blip elsewhere. Some examples might be the 1906 San Francisco earthquake or the 1900 Galveston hurricane. Iceland’s a bit of an unusual case. First, because the country is so small and insular that anything that happens tends to get held in a sort of national memory. Second, there is a long tradition of oral histories going back to the days of the sagas, so that even the most well-connected and modern Icelander tends to remember these old stories. Me: What was the most striking place/feature you saw in Iceland related to the eruption?
Jon Steingrimsson memorial chapel in Klaustur.
Alexandra Witze & Jeff KanipeWitze and Kanipe: Physically, the Laki lava flows are visually striking. They are covered with an ethereal-looking greenish Arctic moss, so that you drive mile after mile through this soft rolling landscape. It’s hard to imagine it was all a roiling sea of molten rock just a few centuries ago. Culturally, we became fascinated with the story of Jón Steingrímsson, the Lutheran pastor who witnessed the Laki eruption and became its scientific chronicler. On Easter Sunday of 2014, we were in the town of Kirkjubaejarklaustur where Jón had worked. We watched as a local clergyman held a sunrise service in the chapel built to commemorate Jón’s work during the eruption. We literally got chills on seeing villagers walk through the grounds of the old church where Jón had led his famous fire mass, and the cemetery that contains a mass grave of Laki victims. Past and present seemed to meld in one moment. Me: What were the challenges of trying to extract a geologically-accurate volcanic story from historical records?Witze and Kanipe: Fortunately scientists had already done that work for us. Starting in the early 1990s Thor Thordarson did extraordinary research on Laki, from digging through Icelandic-language records of eyewitnesses to exploring European sources describing the spread of its volcanic haze. He also mapped the crater row for the first time in modern history, and analyzed its lava to come up with estimates for how much sulfur, fluorine and other volatiles it emitted. It’s not an exaggeration to say that nearly everything scientists know about Laki today traces back to something Thor began. Historically, we were lucky in that English-language translations of Jón Steingrímsson’s eruption chronicle and autobiography have become available in recent years. Me: What drew you to working on the Laki eruption in particular? There are a lot of eruptions with good historical records from which to choose, so what made Laki stand out?Witze and Kanipe: It was the human story that drew us. Jón’s story of surviving the eruption is incredible – he lost his wife, his friends, his community, and yet he pushed on. And then you had people across Europe basically freaking out about the eruption, with no idea where this weird haze came from that seemed to be making them sick. There are amazing accounts of scientists like Ben Franklin, in Paris, trying to understand the bizarre phenomena seen in the ‘annus mirabilis’ of 1783 across Europe. There are a lot of eruptions with good historical records, yes, but few with as many widespread and compelling human dramas. Me: How much volcanology did you have to learn during the course of writing the book?Witze and Kanipe: You mean other than reading Eruptions? We spent a lot of time with the Encyclopedia of Volcanoes. [Note from me: I highly recommend that book for those who really want to know about volcanoes.] Me: What is your favorite Icelandic volcano (after the Laki fissures, of course)?Witze and Kanipe: Holuhraun! Because it is so much like Laki.