scholarly journals Late Holocene climatic changes in Tierra del Fuego based on multiproxy analyses of peat deposits.

2004 ◽  
Vol 61 (2) ◽  
pp. 148-158 ◽  
Author(s):  
Dmitri Mauquoy ◽  
Maarten Blaauw ◽  
Bas van Geel ◽  
Ana Borromei ◽  
Mirta Quattrocchio ◽  
...  
Keyword(s):  
Fungal Spores ◽  
Plant Macrofossils ◽  
Medieval Warm Period ◽  
Warm Period ◽  
Tierra Del Fuego ◽  
Ice Age ◽  
Raised Bog ◽  
Climate Fluctuations ◽  
Peat Deposits ◽  
Tree Ring Data

A ca. 1400-yr record from a raised bog in Isla Grande, Tierra del Fuego, Argentina, registers climate fluctuations, including a Medieval Warm Period, although evidence for the ‘Little Ice Age’ is less clear. Changes in temperature and/or precipitation were inferred from plant macrofossils, pollen, fungal spores, testate amebae, and peat humification. The chronology was established using a 14C wiggle-matching technique that provides improved age control for at least part of the record compared to other sites. These new data are presented and compared with other lines of evidence from the Southern and Northern Hemispheres. A period of low local water tables occurred in the bog between A.D. 960–1020, which may correspond to the Medieval Warm Period date range of A.D. 950–1045 generated from Northern Hemisphere tree-ring data. A period of cooler and/or wetter conditions was detected between ca. A.D. 1030 and 1100 and a later period of cooler/wetter conditions estimated at ca. cal A.D. 1800–1930, which may correspond to a cooling episode inferred from Law Dome, Antarctica.

scholarly journals Climate Variability in Central Europe during the Last 2500 Years Reconstructed from Four High-Resolution Multi-Proxy Speleothem Records

Geosciences ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 166
Author(s):  
Sarah Waltgenbach ◽  
Dana F. C. Riechelmann ◽  
Christoph Spötl ◽  
Klaus P. Jochum ◽  
Jens Fohlmeister ◽  
...  
Keyword(s):  
Trace Elements ◽  
High Resolution ◽  
Climate Variability ◽  
Little Ice Age ◽  
Medieval Warm Period ◽  
Warm Period ◽  
Ice Age ◽  
Cold Period ◽  
Cave System ◽  
Dark Ages

The Late Holocene was characterized by several centennial-scale climate oscillations including the Roman Warm Period, the Dark Ages Cold Period, the Medieval Warm Period and the Little Ice Age. The detection and investigation of such climate anomalies requires paleoclimate archives with an accurate chronology as well as a high temporal resolution. Here, we present 230Th/U-dated high-resolution multi-proxy records (δ13C, δ18O and trace elements) for the last 2500 years of four speleothems from Bunker Cave and the Herbstlabyrinth cave system in Germany. The multi-proxy data of all four speleothems show evidence of two warm and two cold phases during the last 2500 years, which coincide with the Roman Warm Period and the Medieval Warm Period, as well as the Dark Ages Cold Period and the Little Ice Age, respectively. During these four cold and warm periods, the δ18O and δ13C records of all four speleothems and the Mg concentration of the speleothems Bu4 (Bunker Cave) and TV1 (Herbstlabyrinth cave system) show common features and are thus interpreted to be related to past climate variability. Comparison with other paleoclimate records suggests a strong influence of the North Atlantic Oscillation at the two caves sites, which is reflected by warm and humid conditions during the Roman Warm Period and the Medieval Warm Period, and cold and dry climate during the Dark Ages Cold period and the Little Ice Age. The Mg records of speleothems Bu1 (Bunker Cave) and NG01 (Herbstlabyrinth) as well as the inconsistent patterns of Sr, Ba and P suggests that the processes controlling the abundance of these trace elements are dominated by site-specific effects rather than being related to supra-regional climate variability.

scholarly journals Vegetation changes in the Hotyn Upland over the last 2000 years (based on pollen data)

2019 ◽  
Vol 28 (1) ◽  
pp. 51-58 ◽  
Author(s):  
N. Gerasimenko ◽  
T. Yurchenko ◽  
Ye. Rohozin
Keyword(s):  
Little Ice Age ◽  
Environmental Changes ◽  
Medieval Warm Period ◽  
Warm Period ◽  
Ice Age ◽  
Humid Climate ◽  
Cool Period ◽  
Surface Samples ◽  
Pollen Surface ◽  
Short Period

Pollen study of two soil sections, located in two different relief positions (the gully bottom at Sadgora 1 and the upper part of a slope at Ridkivtsi I) enables us to show vegetational and climatic changes in the Bukovyna area (the Chernivtsi region) during the last 2000 years (the end of the Early Subatlantic, the Middle and Late Subatlantic). The reconstructions of past vegetation are based on the analyses of pollen surface samples, taken from the soils of different ecotops in the sites’ vicinity. The reconstructed short-period phases of environmental change correspond well with those established in other areas. These are the end of the “Roman warm period” (before the 14C date of 1.74 ka BP), with the humid climate; the relatively dry “Dark Ages cool period” (before the 14C date of 1.19 ka BP); the wet “Medieval warm period”; the cool “Little Ice Age” (with its wetter beginning and drier ending) and the modern warm phase (the last 150 years).Centennial environmental changes − the cooling within the Medieval Warming (XI cent.) and the warming within the “Little Ice Age” (XV cent.) – have been detected. Human impact on the vegetation can be demonstrated – forest clearance (with the presence of particles of microscopic charcoal and pollen of pyrophitic plants), the introduction of thermophilous walnut during warm periods, and the appearance of pasture lands in the place of former fern patches and woods during the “Little Ice Age”, and the last warm phase (with the presence of pollen of pastoral synanthropic plants). In the last 2000 years, broad-leaved woodland, dominated by hornbeam, grew extensively near Sadgora and Ridkivtsi only during the “Medieval Warm Period”.

PRELIMINARY RESULTS FROM POLLEN AND FUNGAL SPORES IN HOLOCENE TERRACE DEPOSITS: EVIDENCE FOR ECOSYSTEM CHANGE FOLLOWING THE MEDIEVAL WARM PERIOD

2017 ◽  
Author(s):  
Emma C. Marriner ◽  
◽  
Noelia B. Nuñez Otaño ◽  
Kristina F. Gardner ◽  
Mercedes M. di Pasquo ◽  
...  
Keyword(s):  
Fungal Spores ◽  
Medieval Warm Period ◽  
Warm Period ◽  
Ecosystem Change ◽  
Preliminary Results

Geological records of changes in wind regime over south Greenland since the Medieval Warm Period: a tentative reconstruction

Polar Record ◽  
2009 ◽  
Vol 45 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Antoon Kuijpers ◽  
Naja Mikkelsen
Keyword(s):  
Atmospheric Circulation ◽  
Medieval Warm Period ◽  
Warm Period ◽  
Ice Age ◽  
East Greenland Current ◽  
Aeolian Deposits ◽  
New Information ◽  
North Atlantic Climate ◽  
Wind Activity ◽  
Marine Data

ABSTRACTPublished marine sediment core records and new information from terrestrial aeolian deposits from the surroundings of Igaliku Fjord, south Greenland, have been used for a tentative reconstruction of multi-decadal to centennial scale changes in the intensity of regional atmospheric circulation since the Medieval Warm Period. The marine data show that aeolian activity over southern Greenland was generally enhanced in the Medieval Warm Period between c. AD 900 and c. AD 1300. The preliminary data from the onshore aeolian deposits suggest that wind activity was strongest after AD 1000, reaching a peak close to AD 1300, after which atmospheric circulation intensity decreased. A comparison with the marine data shows that this decrease coincides with increased advection of Polar Water by the East Greenland Current at the beginning of the Little Ice Age. The aeolian sediment record suggests foehn wind activity displaying multi-decadal oscillations in the range of known north Atlantic climate oscillations. The intensity of erosional processes in south Greenland has previously often been attributed to farming activities initiated after AD 1000 by the Norse who disappeared a few hundred years later. Our findings suggest, however, that erosion in this area is mainly related to marked variations in wind strength.

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