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Bajard, Manon Juliette Andree
(2022).
Agricultural and climatic contexts associated to the Fimbulwinter in the area of Gardermoen: when pre-Viking societies adapted to the climate.
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Ballo, Eirik Gottschalk; Bajard, Manon Juliette Andree; Bakke, Jostein; Støren, Eivind Wilhelm Nagel; D'Andrea, William J. & Høeg, Helge Irgens
(2022).
Lake Sagtjernet hydrogen isotopes and pollen
.
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Ballo, Eirik Gottschalk; Bajard, Manon Juliette Andree; Bakke, Jostein & Støren, Eivind Wilhelm Nagel
(2021).
Using CT scans to count varves: Application to Lake Sagtjernet.
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Ballo, Eirik Gottschalk; Bajard, Manon Juliette Andree; Bakke, Jostein & Støren, Eivind Wilhelm Nagel
(2021).
Using CT scans to count varves in Lake Sagtjernet.
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Bajard, Manon Juliette Andree
(2021).
PC1. Improving food security: new techniques.
[Internett].
Press conference/EGU General Assembly 2021.
Vis sammendrag
"In 2019, nearly 750 million people were exposed to severe levels of food insecurity. Conservative estimates indicate that more than 3 billion people can’t afford healthy diets, and that the social costs of greenhouse gas emissions associated with current food-consumption patterns will top $1.7 trillion per year within the next decade.
This press conference will introduce journalists to some of the latest geoscience research being conducted to help improve global food security, including two types of forecasting that support early warnings in Africa. Additional research strives to improve agricultural management strategies with respect to greenhouse gas emissions and to balance food and water security in cities. Lastly, we will hear how one group of scientists is researching how pre-Viking and Viking societies adapted their agricultural practices to a changing climate to glean fresh insights into how we can improve our future food security." (EGU: 2021)
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Bajard, Manon Juliette Andree & Dacey, James
(2021).
Food Security Lessons from the Vikings.
[Tidsskrift].
EOS Science News by AGU.
Vis sammendrag
Scandinavian societies of the first millennium adapted their farming practices to volcano-driven climate changes.
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Bajard, Manon Juliette Andree
(2021).
PC1. Improving food security: new techniques.
[Tidsskrift].
Press conference/EGU General Assembly 2021.
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ter Schure, Anneke; Bajard, Manon Julietto Andree; Loftsgarden, Kjetil; Høeg, Helge Irgens; Ballo, Eirik Magnus Gottschalk & Bakke, Jostein
[Vis alle 12 forfattere av denne artikkelen]
(2021).
Disentangling anthropogenic and environmental drivers of biological change in southeastern Norway during the Holocene.
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ter Schure, Anneke; Bajard, Manon Julietto Andree; Loftsgarden, Kjetil; Høeg, Helge Irgens; Ballo, Eirik Magnus Gottschalk & Bakke, Jostein
[Vis alle 12 forfattere av denne artikkelen]
(2021).
Anthropogenic and environmental drivers of biological change in southeastern Norway during the Holocene.
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Bajard, Manon Julietto Andree; Ballo, Eirik Magnus Gottschalk; Høeg, Helge I.; Bakke, Jostein; Støren, Eivind N. & Loftsgarden, Kjetil
[Vis alle 11 forfattere av denne artikkelen]
(2021).
Instability or adaptation of the pre-Viking society to the climate variability of the Late Antiquity?
Vis sammendrag
Understanding how agricultural societies were impacted and adapted to past climate variations is critical to adapt to contemporary climate change and guaranty the food security. However, linking climate and change in the behaviour of a population are difficult to evidence. Here, we studied the climate variations of the period between 200 and 1300 CE and its impact on the pre-Viking and Viking societies in south Norway. We used a retrospective approach combining a multi-proxy analysis of lake sediments, including geochemical and palynological analyses, to reconstruct past changes in temperature and agricultural practices during the period 200-1300 CE. We associated variations in Ca/Ti ratio as a result of change in lake productivity with the temperature. The periods 200-300 and 800-1300 CE were warmer than the period between 300 and 800 CE, which is known as the “Dark Ages Cold Period” in the Northern Hemisphere. During this colder period, phases dominated by grazing activities (280-420 CE, 480-580 CE, 700-780 CE) alternated with phases dominated by the cultivation of cereals and hemp (before 280 CE, 420-480 CE, 580-700 CE, and after 800 CE). The alternation of these phases is synchronous of temperature changes. Cold periods are associated to livestock farming, and warmer periods to crop farming. This result suggests that when temperature no longer allowed crop farming, the food production specialized in animal breeding. The development of activities reached a maximum between 400 and 550 CE and a minimum between 680 and 800 CE, in agreement with archaeological findings. The Viking Age (800-1000 CE) started with an increase in temperature and corresponds to the warmest period between 200 and 1300 CE, allowing a larger development of the agriculture practices and society. Our results prove that the pre-Viking society adapted their agricultural practices to the climate variability of the Late Antiquity and that the Vikings expanded with climate warming.
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Bajard, Manon Julietto Andree
(2020).
The hidden face of lakes: how natural archives bring us back to the Viking Age and beyond.
Vis sammendrag
Since 10,000 years, lakes have continuously accumulated sediments. These sediments contain particles of soil, plant, pollen and DNA from the surrounding environment, brought by rivers, runoff and the wind. They allow us to reconstruct the past evolution of the landscapes, the vegetation and agricultural practices, but also climate changes. By studying and dating cores of lake sediments in Norway, we can reconstruct the history of the environment throughout the last 10 000 years and explore the Viking Age.
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Bajard, Manon Julietto Andree; Ballo, Eirik Magnus Gottschalk; Støren, Eivind Wilhelm Nagel; Bakke, Jostein; Høeg, Helge Irgens & Loftsgarden, Kjetil
[Vis alle 8 forfattere av denne artikkelen]
(2020).
Volcanic Eruptions and their Impacts on Climate, Environment, and Viking Society in 500-1250 CE
.
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Bajard, Manon Julietto Andree; Ballo, Eirik Magnus Gottschalk; Støren, Eivind Wilhelm Nagel; Bakke, Jostein; Høeg, Helge Irgens & Loftsgarden, Kjetil
[Vis alle 9 forfattere av denne artikkelen]
(2020).
Record of climate and environmental changes in a dead-ice lake close to Gardermoen told by a 10 000 years old freshwater fish and a Viking King.
Vis sammendrag
We studied a six-meter long sediment sequence retrieved from the kettle lake Ljøgottjern, close to Oslo-Gardermoen Airport, to reconstruct environmental and climate changes during the last millennia. The lake is 18 m depth and located at 185 m a.s.l., under the maximum postglacial sea level. The largest burial mound of Northern Europe was built in the mid-6th century on the shore of this lake allegedly for King Rakni and makes this place ideal to study human-environment interactions in a paleo-perspective approach.
Using a multi-proxy sedimentological analysis of this record, including 14C dating, paleo-secular variations, XRF and CT scans, and pollen, this study highlights different climate patterns throughout the Holocene.
At the bottom of the core, a carbonated sandy-clayey layer with centimetric twigs overlays an organic rich black peaty-type layer, suggesting a continental environment. On top of that, a disturbed clay layer containing fish bones from a freshwater Carpinidae species was found. The fish could have been buried by the massive (70 cm) sandy carbonated deposit covering it. A sharp transition separates a clay cap on top of the deposit and the start of a finely laminated lacustrine sedimentation dated 9.3 ka cal. BP. The massive deposit could be associated to the outburst flood from the glacial lake Nedre Glomsjø dated 10-10.4 ka cal BP (Longva, 1984; Høgaas and Longva, 2016).
A major change in the sedimentation occurred around 8 ka cal. BP, with darker sediments and a lower sedimentation rate. This change could be related to a warming climate and stabilization of the catchment by soil and forest development around the lake in the mid-Holocene. The sedimentation rate increased again between 2000 and 3000 years cal. BP as a result of the development of first human activities and major change in the vegetation (Høeg, 1997). We reconstructed temperature changes during the first millennia and compared it to societal dynamics. The period between 300 and 800 years cal. CE is colder than the period 800-1300 years cal. CE. After 1600 years cal. CE, an increase in erosion could be associated to the extension of the population and agriculture in Scandinavia and revealed a chronicle of the major floods in this area.
The presence of freshwater fish older than 9,3 ka attests of their early and natural colonization of Scandinavian lakes. The comparison of this record with archaeological data will allow us to discuss socio-environmental dynamics following the deglaciation in the area.
References:
Smith, A.A. 2010. CO2 stor¬age. Journal of Sciences 32, 10-20.
Høeg, H.I., 1997. Pollenanalytiske undersøkelser på Øvre Romerike : Ullensaker og Nannestad, Akershus fylke : Gardermoprosjektet, Varia (Universitetets oldsaksamling : trykt utg.). Universitetets oldsaksamling, Oslo.
Høgaas, F., Longva, O., 2016. Mega deposits and erosive features related to the glacial lake Nedre Glomsjø outburst flood, southeastern Norway. Quat. Sci. Rev. 151, 273–291. https://doi.org/10.1016/j.quascirev.2016.09.015
Longva, O., 1984. Romeriksmjelen danna ved ein storflaum på Austlandet for vel 9000 år siden. Norges geologiske undersøkelse, Årsmelding 1984 8–11.
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Bajard, Manon Julietto Andree; Ballo, Eirik Magnus Gottschalk; Støren, Eivind Wilhelm Nagel; Bakke, Jostein; Høeg, Helge Irgens & Loftsgarden, Kjetil
[Vis alle 9 forfattere av denne artikkelen]
(2020).
Tracing socio-environmental dynamics and climate changes in the period 300-1300 CE in Scandinavia from lake sediments.
Vis sammendrag
Understanding large volcanic eruptions impacts on environments and societies is necessary to consider future climate and socio-environmental interactions. Lake sediments can record these dynamics on a continuous long time scale and include at the same time footprints from volcanic eruptions, climate changes and human activities.
We analysed the sediments of Lake Ljøgottjern, located southeastern Norway. The largest burial mound of Northern Europe was built in the mid-6th century on the shore of this lake and makes this place an ideal site to study human-environmental interactions throughout the last millennia.
Using a multi-proxy analysis of this sedimentary record, including 14C dating, geochemistry, as well as palynological data, we reconstructed temperature and socio-environmental changes in this area between 300 and 1300 CE (Common Era).
We associated changes in Ca/Ti ratio with changes in temperature. The period between 300 and 800 CE was colder than the periods 200-300 and 800-1300 CE. Five abrupt cooling events seem to be linked to weakened positive NAO (North Atlantic Oscillation) phases, and two of them can also be linked to the two largest volcanic events of the period (i.e. the 536/540 CE double event, and 1257 CE eruption of Samalas).
Palynological data indicate a decrease of the human activities and reforestation of the area in the 6th century. This abandonment is consistent with archaeological findings and could be related to the 536/540 cooling event. Very little activities are then recorded between 700 and 850 CE. Agricultural activities start again strongly in the Viking age with increase in temperature.
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Ballo, Eirik Magnus Gottschalk; Bajard, Manon Julietto Andree; Bakke, Jostein & Støren, Eivind Wilhelm Nagel
(2019).
Reconstructing climate and socio-environmental changes using lake sediments
.
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Ballo, Eirik Magnus Gottschalk; Bajard, Manon Julietto Andree; Bakke, Jostein & Støren, Eivind Wilhelm Nagel
(2019).
Reconstructing climate and socio-environmental changes using lake sediments
.
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Ballo, Eirik Magnus Gottschalk; Bajard, Manon Julietto Andree; Bakke, Jostein & Støren, Eivind Wilhelm Nagel
(2019).
Reconstructing climate and socio-environmental changes using lake sediments
.
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Ballo, Eirik Magnus Gottschalk; Bajard, Manon Julietto Andree; Støren, Eivind Wilhelm Nagel; Bakke, Jostein & Svensen, Henrik
(2019).
High-resolution lacustrine records of
environmental changes in Scandinavia:
a focus on the Migration period and Viking age.
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Ballo, Eirik Magnus Gottschalk; Bajard, Manon Julietto Andree; Støren, Eivind Wilhelm Nagel; Bakke, Jostein & Svensen, Henrik
(2019).
High-resolution lacustrine records of
environmental changes in Scandinavia:
a focus on the Migration period and Viking age.
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Ballo, Eirik Magnus Gottschalk; Bajard, Manon Julietto Andree; Støren, Eivind Wilhelm Nagel; Bakke, Jostein & Svensen, Henrik
(2019).
High-resolution lacustrine records of
environmental changes in Scandinavia:
a focus on the Migration period and Viking age.
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Ballo, Eirik Magnus Gottschalk; Bajard, Manon Julietto Andree; Støren, Eivind Wilhelm Nagel; Bakke, Jostein & Svensen, Henrik
(2019).
High-resolution lacustrine records of environmental changes in Scandinavia: a focus on the Migration period and the Viking age.
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Bajard, Manon Julietto Andree; Støren, Eivind Wilhelm Nagel; Bakke, Jostein & Svensen, Henrik
(2019).
High-resolution lacustrine records of environmental changes in Scandinavia: a focus on the Migration period and Viking age.
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Bajard, Manon Julietto Andree & Eirik, Ballo
(2019).
First insight in Norwegian sedimentary archives
.
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Bajard, Manon Julietto Andree; Jérôme, Poulenard; Pierre, Sabatier; Anne-Lise, Develle; Fernand, David & Jacques-Louis, De Beaulieu
[Vis alle 17 forfattere av denne artikkelen]
(2019).
Non-linear soil evolution trajectories from the Holocene to the Anthropocene.
Vis sammendrag
Soils have a substantial role in the environment as they give back several ecosystem services as food supply and carbon storage. But agricultural practices can modify soil properties and soil evolution processes, threatening these services. These modifications are poorly studied and resilience/adaptation times of soils to disruptions are unknown on pedogenesis time scale.
Lake sediment sequences can be used as continuous archives of long soil evolution. The study of four lake-catchment systems from the western North Alps inquires both soil evolution and the development of human activities throughout the Holocene.
The compared multiproxy analysis of sedimentary sequences of Lake La Thuile (875 m, Bauges), Lake Bénit (1450 m, Bargy), Lake Gers (1540 m, Giffre), Lake Verney (2088 m, Italy, Petit Saint-Bernard Pass) and the soils of their catchment, allowed to decipher the interactions between agro-pastoral system, erosion and soils. Our main objective is to determine whether human became, over the Holocene, the overriding factor of the pedogenesis and what are the ecosystem responses to disruptions, in terms of resilience and sustainability.
The comparison of paleoenvironmental reconstructions, derived from lacustrine archives evidenced a progressive development of soils during the first part of the Holocene, associated with substrate decarbonatation, acidification then podzolization of soils in the Holocene Climate Optimum. The second part of the Holocene is characterized by regressive pedogenesis, in response to agro-pastoral activities development, mainly around the Roman and Medieval periods, along with erosion increases. Environmental disruptions triggered colluviation movements and a regression of soil weathering, leading to a multiplication of (non-linear) soil evolution trajectories and a higher soil diversity in the Anthropocene.
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Bajard, Manon Julietto Andree; Eirik, Ballo; Jostein, Bakke; Eivind, Støren; Helge, Høeg & Frode, Iversen
[Vis alle 8 forfattere av denne artikkelen]
(2019).
Socio-environmental dynamics and volcanic eruptions in the 500-1250 CE period in Scandinavia: new sight in Lake Ljøgottjern sediment sequence.
Vis sammendrag
Large volcanic eruptions are the major drivers of climate variability in the pre-industrial era of the last two millennia. Understanding their impacts on societies is necessary to consider future climate and socio-environmental interactions. Lake sediments can record these dynamics on a continuous time scale and include at the same time footprints from volcanic eruptions, climate changes and human activities associated to vegetation changes. Lake Ljøgottjern is located in southeastern Norway and is of glacial origin. The lake is 18 m depth, groundwater-fed and provide a sediment sequence covering the last 8000 years. The largest burial mound of Norway was built in the mid-6th century on the shore of this lake for King Rakni and makes this place an ideal site to study human-environmental interactions throughout the last millennia, confronting them to archaeological evidences.
Using a high-resolution multi-proxy analysis of this record, including 14C dating, sedimentological and both mineral and organic geochemical analyses as well as palynological data, this study will allow reconstructing climate and socio-environmental changes in this area, with a focus on the 500-1250 CE (Common Era) period.
A previous palynological study evidenced the first openings of the environment linked to the development of agriculture between 3000 and 3500 yrs cal. BP. This change in land use was associated with changes in the geochemistry of the sediment. Maximum anthropogenic impacts were recorded in ca. 600 CE, when the mound was raised, and in the Little Ice Age, between the 13th and 17th centuries. The pollen diagram of Lake Ljøgottjern presents also three substantial decreases in charcoal particles between 500 and 1250 CE. An updated and high resolution dating of the new sequence will allow to associate or not these changes in fire regimes to major volcanic events (i.e., 536-540 unknown, 939 Eldgjà and 1257 Samalas).
The comparison of this record with other environmental archives from Norway, as well as climate reconstructions from ice cores and tree rings will allow us to discuss resilience times and adaptation of the Viking society in a changing Scandinavian environment.
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Bajard, Manon Julietto Andree; Eirik, Ballo; Jostein, Bakke; Eivind, Støren; Helge, Høeg & Frode, Iversen
[Vis alle 8 forfattere av denne artikkelen]
(2019).
Socio-environmental dynamics and volcanic eruptions in the 500-1250 CE period in Scandinavia: new sight in Lake Ljøgottjern sediment sequence.
Vis sammendrag
Large volcanic eruptions are the major drivers of climate variability in the pre-industrial era of the last two millennia. Understanding their impacts on societies is necessary to consider future climate and socio-environmental interactions. Lake sediments can record these dynamics on a continuous time scale and include at the same time footprints from volcanic eruptions, climate changes and human activities associated to vegetation changes. Lake Ljøgottjern is located in southeastern Norway and is of glacial origin. The lake is 14 m depth, groundwater-fed and provide a sediment sequence covering the last 8000 years. The largest burial mound of Norway was built in the mid-6th century on the shore of this lake for King Rakni and makes this place an ideal site to study human-environmental interactions throughout the last millennia, confronting them to archaeological evidences.
Using a high-resolution multi-proxy analysis of this record, including 14C dating, sedimentological and both mineral and organic geochemical analyses as well as palynological data, this study will allow reconstructing climate and socio-environmental changes in this area, with a focus on the 500-1250 CE (Common Era) period.
A previous palynological study evidenced the first openings of the environment linked to the development of agriculture between 3000 and 3500 yrs cal. BP. This change in land use was associated with changes in the geochemistry of the sediment. Maximum anthropogenic impacts were recorded in ca. 600 CE, when the mound was raised, and in the Little Ice Age, between the 13th and 17th centuries. The pollen diagram of Lake Ljøgottjern presents also three substantial decreases in charcoal particles between 500 and 1250 CE. An updated and high resolution dating of the new sequence will allow to associate or not these changes in fire regimes to major volcanic events (i.e., 536-540 unknown, 939 Eldgjà and 1257 Samalas).
The comparison of this record with other environmental archives from Norway, as well as climate reconstructions from ice cores and tree rings will allow us to discuss resilience times and adaptation of the Viking society in a changing Scandinavian environment.
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Svensen, Henrik; John, Timm; Weyer, Stefan; Fristad, Kirsten; Polozov, Alexander & Bajard, Manon Julietto Andree
[Vis alle 8 forfattere av denne artikkelen]
(2019).
Bacterial sulphate- and iron reduction in a Siberian Traps crater lake during the end-Permian crisis .
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Bajard, Manon Julietto Andree; Eirik, Ballo; Henrik, Svensen; Helge, Høeg; Frode, Iversen & Jostein, Bakke
[Vis alle 7 forfattere av denne artikkelen]
(2018).
Norwegian lakes and what they can tell us about the Vikings
.
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Bajard, Manon Julietto Andree & Kirstin, Krüger
(2018).
VIKINGS Project
Volcanic Eruptions and their Impacts on Climate, Environment,
and Viking Society in 500-1250 CE
.