Archives par mot-clé : Iceland

Today’s Iceland Colder, Icier Than In Last 8,000 Years (Except the 1800s)

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.

Read more at No Tricks Zone

3000-Year-Old Trees Excavated Under Icelandic Glacier

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.

https://www.icelandreview.com/news/3000-year-old-trees-excavated-under-glacier/

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.

Iceland’s monster volcano charging up for eruption

by Anthony Watts, September 20, 2018 in WUWT


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.

N ICE CAULDRON IN MÝRDALSJÖKULL Geothermal activity in the volcano’s caldera melts the glacier, creating cauldrons in the ice. Photo/Fréttablaðið