Main topic : Iceland attracts tourists as much as it does scientists tasked with forecastingthe significant natural hazards inherent in its unique geological context. There’s not aweek goes by when Iceland doesn’t feature prominently in the media, and even more sotoday with the evacuation of the population on 11 November following the awakening ofthe volcano at Grindavik, 40km southwest of Reykjavik.
The current eruption has been forecast since 21 July 2023, and was activated in December and on 14 January 2024. This is neither the first nor the last time that volcanism has made or will make news. Grindavik isnot the only eruption underway: between 40 and 50 of the 1,330 known volcanoes on Earth are erupting at any one time. This eruptive activity is accompanied by ‘disastrous’ effectssuch as frequent earthquakes, sulphur and ash aerosols, sub-glacial melting of the ice caps, glacio-isostatic discharges, and uplift… Yes, Iceland is under close survey… because it is located on an active hot spot.
Laki or ‘Lakagigar’ is a volcanic system in the graben across Iceland. Colossal fissure erupti
Less than a year has passed since lava stopped sputtering from Iceland’s Reykjanes Peninsula following the first major volcanic outburst from this region in almost 800 years. But now the island is once again bleeding molten rock. The start of a new eruption so soon after unrest in 2021 seems to underscore that this once quiescent peninsula has awoken from its long slumber.
“This could herald the start of decades of occasional eruptions,” says Dave McGarvie, a volcanologist at Lancaster University.
The new eruption, which started at 1:18 p.m. local time on August 3, sent scarlet ribbons streaming from the base of a small mountain into the uninhabited Meradalir Valley. Located far from populations, the volcanic burbles likely pose little danger to the public, at least in the near term. And this relative safety allows scientists and tourists alike to marvel at the geologic majesty and get excited for a possible onslaught of new scientific knowledge.
After all, each volcanic eruption here provides a “window into the abyss,” McGarvie says. The 2021 event yielded revelations about the personality of the peninsula’s exuberant eruptions—from their physical behaviors to their quirky chemistries. This new eruption promises even more insights as the nascent volcano forges the world’s youngest land.
It’s still unclear how prolific or lengthy the eruption will be; this information will only come to light with more time and continued monitoring. But this week’s show of fireworks strongly hints the peninsula will become one of the most volcanically active parts of the planet for several generations.
Permafrost developed from Termination Ia (Bölling interstadial, 14.5 cal ka BP) in Northern Iceland, in answer to deglaciation. Permafrost persisted or even re-extended during the Preboreal cooling events (at 11.2, 10.3 and 9.3 cal ka BP) synchronic with pulsated glacial advances. It disappeared below 1000 masl during the Thermal Optimum (8-5 cal ka BP). The present-day re-extent was controlled with the cooling related with the Little Ice Age and particularily the Maunder solar Minimum. Continuous permafrost is stable above 1000 masl, but is today melting between 900 and 800 masl. Discontinuous permafrost is vanishing today with the recent climate warming (from 1970), especially in palsa bogs, and on valley slopes with thermokarstic mass wasting.
The February 2021 data for Iceland and Greenland are available from the Japan Meteorological Agency (JMA), which means the latest meteorological DJF winter mean temperature can be computed.
Icelandic winters have cooled since 2001
We plotted the JMA data for three stations (the ones with sufficient data) in Iceland. Result: no warming over the past 18 winters!
A “seismic crisis” has been occurring in the area near Fagradalsfjall since late Feb 2021. This activity has been interpreted as intrusion of magma at shallow depths, which could lead to a new eruption.
Fadradalsfjall is a Pleistocene table mountain in the Reykjanes Peninsula, NE of Grindavik, Iceland.
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Of today’s reawakening volcanoes, those located in Iceland are perhaps the most concerning.
It is this highly-volcanic region that will likely be home to the next “big one” (a repeat of the 536 AD eruption that took out the Roman Republic…?) — the one that will return Earth to another volcanic winter.
Volcanic eruptions are one of the key forcings driving Earth into its next bout of global cooling.
Volcanic ash (particulates) fired above 10km –and so into the stratosphere– shade sunlight and reduce terrestrial temperatures. The smaller particulates from an eruption can linger in the upper atmosphere for years, or even decades+ at a time.
Today’s worldwide volcanic uptick is thought to be tied to low solar activity, coronal holes, a waning magnetosphere, and the influx of Cosmic Rays penetrating silica-rich magma.
Both NOAA and NASA appear to agree, if you read between the lines, with NOAA saying we’re entering a ‘full-blown’ Grand Solar Minimum in the late-2020s, and NASA seeing this upcoming solar cycle (25) as “the weakest of the past 200 years”, with the agency correlating previous solar shutdowns to prolonged periods of global cooling here.
Furthermore, we can’t ignore the slew of new scientific papers stating the immense impact The Beaufort Gyre could have on the Gulf Stream, and therefore the climate overall.
By Die kalte Sonne
[German text translated by P. Gosselin]
Many glaciers are currently shrinking, as they have always done in the past when the climate warmed up. What’s the news on the glacier front?
In August 2019, the Okjokull Glacier disappeared in Iceland with great media attention. The BBC reported:
Climate change: Iceland holds funeral for melted glacier
The glacier called Okjokull is the first in the country to be lost to climate change, after the warmest July ever on record. Iceland loses about 11 billion tonnes of ice per year, and scientists have warned that there are about 400 other glaciers also at risk. They fear all of the island’s glaciers will be gone by 2200. Glaciers cover about 11% of Iceland’s surface.”
Crater study offers window on temperatures 3.5 billion years ago
Once upon a time, seasons in Gale Crater probably felt something like those in Iceland. But nobody was there to bundle up more than 3 billion years ago.
The ancient Martian crater is the focus of a study by Rice University scientists comparing data from the Curiosity rover to places on Earth where similar geologic formations have experienced weathering in different climates.
Iceland’s basaltic terrain and cool weather, with temperatures typically less than 38 degrees Fahrenheit, turned out to be the closest analog to ancient Mars. The study determined that temperature had the biggest impact on how rocks formed from sediment deposited by ancient Martian streams were weathered by climate.
The study by postdoctoral alumnus Michael Thorpe and Martian geologist Kirsten Siebach of Rice and geoscientist Joel Hurowitz of State University of New York at Stony Brook set out to answer questions about the forces that affected sands and mud in the ancient lakebed.
Data collected by Curiosity during its travels since landing on Mars in 2012 provide details about the chemical and physical states of mudstones formed in an ancient lake, but the chemistry does not directly reveal the climate conditions when the sediment eroded upstream. For that, the researchers had to look for similar rocks and soils on Earth to find a correlation between the planets.
by K. Richard, Dec 15, 2020 in ClimateChange Dispatch
A wealth of new research in glacier and sea ice extent shows modern Iceland is 2-4°C colder than all of the last 8,000 years except for a slightly colder late 19th century.
Even the 1700s were warmer with less ice than today in and around Iceland.
A new study (Geirsdóttir et al., 2020) now affirms peak Holocene warmth at least “∼3–4 °C above modern in Iceland” prevailed throughout much of the last 8,000 years.
Data from tree growth, glacier-induced soil erosion, algae productivity, sea ice biomarker proxies (IP25), and other climate indices affirm these conclusions.
Harning et al., 2020 report an overall 7°C Holocene cooling trend In Iceland’s surrounding sea surface temperatures (SST).
“In terms of foraminifera-reconstructed SST, there is an overall trend of cooling throughout the last 8 ka from ~10 °C to ~3 °C.”
It is only in the last few centuries of the modern era that temperatures sharply plummeted to their lowest values of the last 10,000 years (Geirsdóttir et al., 2020).
“The coolest climate of the last 10 ka occurred in the late 1800s CE.”
Consequent to the peak cooling, glaciers and sea ice reached their maximum extents of the Holocene just 150 years ago.
While Iceland’s glaciers and North Shelf sea ice extent did partially recover in the first half of the 20th century, the ice extents are still beyond what they were in the 1700s and earlier.
There is nothing to indicate modern warmth or ice recession in and around Iceland is unprecedented or even unusual.
by P. Homewood, December 12, 2019 in NotaLotofPeopleKnowThat
Ancient tree stumps found under Breiðamerkurjökull glacier in Southeast Iceland are confirmed to be roughly 3,000 years old. RÚV reports.
A specialist believes the remarkably well-preserved stumps were part of a massive forest that disappeared after a long period of a warm climate.
One of the tree stumps was found in Breiðamerkursandur a couple of months ago, and once it was being salvaged a second, larger one was found. The smaller one was sent for examination while the larger will be examined at a later time.
Examinations revealed that the tree stump died very quickly at 89-years-old in the month of June. Nearby sediments and data suggest that the glacier itself was the culprit.
The tree stumps are from a period when Iceland was covered in forests. Even though 9th century Norse settlers reported vast forests across the country, it is believed that 3,000 years ago, the forests were much larger, even reaching the highlands. Approximately 500 BC, the climate became colder and glaciers began to form, destroying parts of the forests.
The 3,000-year-old remains of the forest are very well preserved and will be researched thoroughly. “It is absolutely incredible just how well preserved this tree stump is, having been buried under a glacier and that it still looks so whole, as opposed to being all wrinkled up like many of the specimens we have found.” Once examinations conclude, the water will be extracted from the tree stump and it will be filled with wax instead, allowing it to be exhibited.
Discovering ancient forests under receding glaciers is not confined to Iceland. Remains of trees dating back to the Middle Ages have been found under the Juneau and Exit Glaciers in Alaska, as well under glaciers in Patagonia.
Tree stumps have also turned up under Swiss glaciers, carbon dated to about 4000 years ago.
The simple reality is that glaciers worldwide expanded enormously during the Little Ice Age, arguably to their greatest extent since the Ice Age. Despite decades of retreat since the 19thC, they are still abnormally large by historical standards.
The Katla volcano, hidden beneath the ice cap of Mýrdalsjökull glacier in Iceland, has historically erupted violently once every 40-80 years. In-as-much as it’s last such eruption took place one hundred years ago, in 1918, Katla’s next eruption is long overdue.
An eruption in Katla would dwarf the 2010 Eyjafjallajökull eruption, scientists have warned.
A new study by Icelandic and British geologists showed that Katla is emitting enormous quantities of CO2 – at least 20 kilotons of CO2 every day. Only two volcanoes worldwide are known to emit more CO2, Evgenia Ilyinskaya a volcanologist with the University of Leeds told the Icelandic National Broadcasting Service RÚV.
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N ICE CAULDRON IN MÝRDALSJÖKULL Geothermal activity in the volcano’s caldera melts the glacier, creating cauldrons in the ice. Photo/Fréttablaðið
by Tony Heller, May 22, 2018 in TheDeplorableClimateScienceBlog
Settled science at NASA means constantly rewriting the past. Here are a few of the NASA Reykjavik, Iceland temperature graphs I have captured over the past six years.
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La géologie, une science plus que passionnante … et diverse
