This was a talk focusing on the far reaching environmental and human impacts that 3 eruptions in Europe had in the last 13,000 years from Felix Reide (see Scientist Fact File). It encompassed many different collaborating scientists working together to create a story of change. Something a bit different to what I’ve talk about before but just as interesting, if not more so.
Blog Theme: volcanic induced environmental change in the past and how it could affect our future
Ongoing Blog Theme: climate change on Earth: past and present – the things that have and will change and what we can do about it
What was the talk about?
The talk discussed 3 eruptions associated with environmental and societal change in the northern regions of Europe. Past eruptions are synonymous with extinction, and floral and faunal turnover like the end Permian and end Cretaceous mass extinctions (and their associated volcanic eruptions – the Deccan traps and Siberian trapps). Felix’s talk focused on eruptions occurring in Europe starting at the end of the Pleistocene (the end of the last ice age in Europe). Talking briefly about the scale of the eruptions, Felix looked more closely at the ways these eruptions affected the climate across Europe and how this in turn affected human societies at the time.
1) Laacher See volcano, 13,000 ka
The Laacher See volcano is an active volcano in Germany. It erupted 13,000 years ago forming a large crater that is now filled with a lake, forming a beautiful but deadly area (see Figure 1).
It is still active today as CO₂ is constantly bubbling up through the lake. The volcano also emits deep low frequency earthquakes showing that there is still movement in the magma chamber.
The eruption 13ka years BP was one of the largest eruptions in the northern hemisphere in the past 40,000 years. It had a VEI of 6 (refer to Information Box 1) – larger than the Pinatubo eruption in 1991 and produced 20km³ of volcanic material.
Rain and groundwater would have interacted with the magma to form a very explosive eruption that would have continued for several months. Debris from the eruption blocked the Rhine causing much flooding, coupled with the production of multiple lahars (see Information Box 2).
The eruption was so powerful that is sealed off and preserved the late ice age environment beneath the ash (also called tephra). Preserved burnt trees and forests were found as well as animal tracks in the ash layers from bears, birds and horses. However, no human remains were found immediately above the tephra. Immediately below the tephra were the remains of fishing spears and other tools that showed there was a human presence in the area before the eruption.
What did the eruption do to the rest of Europe ?
Tephra fallout would have spread to cover a large proportion of Europe and terminated human settlements all over the continent – this is because at archaeological sites there are no human settlements directly on top of the tephra. Populations would have been fragmented and from archaeological excavations in Scandinavia, cultural change was brought about due to the eruption. After the eruption human populations were impoverished and led simpler lives. We know this because there was less art and culture and simpler tools were used compared to before the eruption.
The tephra would have caused multiple hazards such as blocking out the sun and causing up to 8 months of solid darkness as well as causing intense lightning storms. Due to the aerosols produced by the volcano, the climate would have been much colder due to less solar radiation being able to permeate into the atmosphere.
The eruption occurred in the spring/summer and would have destroyed animal and plant life, breaking the food chains and making the areas almost unlivable. The fine-grained ash would have made breathing difficult and the very hard grained ash particles would have caused tooth wear. The hard ash caused fluoride poisoning (very nasty) and if animals were to graze on ash covered vegetation, the ash would grind against their teeth causing them to wear out quicker than they would usually. Coupled with this, the fluoride in the ash would have softened the enamel and tooth causing them to wear away until an animal would starve due to it being unable to eat (see Fact Box).
2) Santorini eruption, 3600 BP
The island eruption of Santorini (see Figure 2) in Greece was a large and devastating eruption that caused much cultural change throughout Europe. The Minoan empire was based on the island of Santorini and was an important port for trading goods throughout Europe. The entire island is covered in volcanic deposits from the eruption and it had a VEI of 6 but was larger than the Laacher See eruption. Lots of people, goods and vessels were wiped out and the nearby island of Crete was impacted by a large tsunami.
After the eruption pottery style changed from floral to much darker marine styles. The eastern Mediterranean to Turkey was affected by ash fallout and the devastation from the eruption was thought to form the basis for the legend of Atlantis. As Santorini was such an important trading post, its destruction had geopolitical effects, and as such the Minoan empire collapsed.
How did the eruption affect the far north of Europe?
In Scandinavia, Bronze age people fled from the Mediterranean to the north of Europe and brought with them their trade-based knowledge. From excavations in Scandinavia after the eruption, the artefacts recovered started to mimic the Mediterranean ways of style and fighting. However, this golden age across Europe soon ended as the eruption started to have an effect on the climate. Dendrochronology studies (see Information Box 3) in Norway show that there was a massive drop in temperature and coupled with the archaeological record, showed that this caused major cultural changes. The beautiful artefacts were replaced with simple tools and the population became more reliant on reindeer for warm clothing.
3) Fimbul winter, 535 AD
The Fimbul winter was a period of prolonged climate change in Europe linked to an eruption possibly in Indonesia or Alaska, although it is not known which. The changes started around 535AD which was part of the Iron Age in Europe and lasted several decades. Northern Europe was severely affected by frost and the colder climates aided the spread of the ergot fungus (see Information Box 4 and Figure 3). This increase in the fungus coincided with a 50% decrease in the population.
Low lying lands is Europe became swampy and impossible to build on. Before 535AD, populations in Europe worshipped sun gods for good harvests. After 535AD this belief in the sun god failed as no more amulets and trinkets depicting those deities are ever depicted. The harsher Norse mythology then replaced the sun gods in the North of Europe and some of the myths even picture the sun being swallowed by a wolf.
Present day threats
Given modern societies infrastructure and global trade routes, volcanic eruptions can have huge impacts on current society. There are many large and active volcanoes close to major airports e.g. Laki, Iceland, could affect airports in London and Paris if it erupted. If a major eruption occurred in Europe to rival that of Santorini or Laacher See, Europe would be devastated and isolated from the rest of the world.
Current infrastructure is very susceptible to tephra fall – crops and forests would be covered in ash, causing fluoride poisoning for animals and even humans. Fine grained ash would cause respiratory problems and buildings and roads would be swamped in ash. Given how much devastation snowfall can cause in Europe, it is worrying to imagine how society would cope with a large eruption.
How suitable were the techniques used?
Dendrochronology
Although it can provide data relating dates to environmental conditions, the technique is limited to the last 12,000 years. This is due to the ages of trees being less than this and that before the Holocene (our current geological epoch) the glaciation across Europe in the Quaternary would have removed most trees prior to this date. Overall, the technique is very suitable for recent dates.
Archaeological Excavations
There can be issues with preservation at archaeological sites, meaning that some evidence may have been removed or stolen or have rotted away. There are also issues with finding enough tree debris e.g. timber from archaeological sites due it rotting or being discarded due it not looking as valuable as other artefacts. This can make accurately dating sites difficult sometimes. This can sometimes make excavations subjective as conclusions can only be made from material that is present. However, the technique is well used and can supply us with information about past people and how they lived.
How did the talk advance our knowledge?
The topic is an important and relevant one for Europe today as it focused on large eruptions and how they devastated Europe. Applying the lessons learned from these past eruptions can help us understand how a modern eruption in Europe would affect modern society today. Volcanic eruptions also cause much havoc with the climate which is another issue modern society faces.
To find out more follow these links:
Felix Reide and his current research: http://au.academia.edu/FelixRiede
Laacher See: https://www.academia.edu/37652235/Rockshelters_and_the_impact_of_the_Laacher_See_eruption_on_Late_Pleistocene_foragers
Thank you for reading!
My next post covers mangrove restoration and follows the theme of climate change.
References
Environmental Science. (2019). Dendrochronology: What Tree Rings Tell Us About Past and Present. Available at: https://www.environmentalscience.org/dendrochronology-tree-rings-tell-us [Accessed: 01/02/2019]
Greek Reporter. (2015). Taking a Look At What Makes Santorini So Special. Available at: https://greece.greekreporter.com/2015/07/19/taking-a-look-at-what-makes-santorini-so-special/ [Accessed: 01/02/2019]
Nothing Too Trivial. (2014). Ergot poisoning: the original Purple Haze. Available at: https://jackiefox1976.wordpress.com/tag/ergot-poisoning/ [Accessed: 01/02/2019]
SWR. (2019). Available at: https://www.swr.de/swraktuell/rheinland-pfalz/koblenz/Messergebnisse-des-Landeserdbebendiensts-Rheinland-Pfalz-Erdbeben-und-Magma-unter-dem-Laacher-See,vulkane-eifel-magma-steigt-nach-oben-100.html [Accessed: 01/02/2019]
USGS. (2016). Glossary – VEI. Available at: https://volcanoes.usgs.gov/vsc/glossary/vei.html [Accessed: 01/02/2019]
USGS. (2017). Volcano Updates. Available at: https://volcanoes.usgs.gov/vhp/lahars.html [Accessed: 01/02/2019]
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