Successive Oceanic and Solar Forcing Indicated by Younger Dryas and Early Holocene Climatic Oscillations in the Jura

1995 ◽  
Vol 43 (3) ◽  
pp. 279-285 ◽  
Author(s):  
Michel Magny
Keyword(s):  
Lake Level ◽  
Younger Dryas ◽  
Early Holocene ◽  
Solar Forcing ◽  
Proxy Data ◽  
Climatic Oscillations ◽  
Middle Latitudes ◽  
The Alps ◽  
Second Period ◽  
Recent Extension

AbstractThe recent extension of (1) the residual Δ14C curve back to 11,400 cal yr B.P. and (2) the lake-level reconstruction in the Jura back to ca. 13,500 cal yr B.P. offers the opportunity of testing by proxy data the relationships between climate, atmospheric 14C, the sun, and the ocean recently suggested from the atmospheric 14C record. The climatic significance of the Jura record is supported by correlations with climatic oscillations reconstructed in the Alps from glaciers and timberline movements. Correspondence between the 14C and paleoclimatic record from the Jura suggests a working hypothesis: two intervals within the Holocene can be distinguished in the middle latitudes of western and central Europe. An early Holocene period shows abrupt climatic oscillations linked to ocean forcing. Major colder climate phases developed between ca. 9000 and 8800, and between ca. 8000 and 7000 cal yr B.C. that coincide with higher Δ14C values. After 6000 cal yr B.C., a second period is characterized by smoother multicentury climatic oscillations linked to solar forcing.

scholarly journals Revisions and Extension of the Hohenheim Oak and Pine Chronologies: New Evidence About the Timing of the Younger Dryas/Preboreal Transition

Radiocarbon ◽  
1998 ◽  
Vol 40 (3) ◽  
pp. 1107-1116 ◽  
Author(s):  
Marco Spurk ◽  
Michael Friedrich ◽  
Jutta Hofmann ◽  
Sabine Remmele ◽  
Burkhard Frenzel ◽  
...  
Keyword(s):  
Calibration Curve ◽  
Younger Dryas ◽  
Ice Cores ◽  
Early Holocene ◽  
Proxy Data ◽  
The Past ◽  
Varve Chronology ◽  
New Evidence ◽  
Radiocarbon Calibration

Oak and pine samples housed at the Institute of Botany, University of Hohenheim, are the backbone of the early Holocene part of the radiocarbon calibration curve, published in 1993 (Becker 1993; Kromer and Becker 1993; Stuiver and Becker 1993; Vogel et al. 1993). Since then the chronologies have been revised. The revisions include 1) the discovery of 41 missing years in the oak chronology and 2) a shift of 54 yr for the oldest part back into the past. The oak chronology was also extended with new samples as far back as 10,429 BP (8480 BC). In addition, the formerly tentatively dated pine chronology (Becker 1993) has been rebuilt and shifted to an earlier date. It is now positioned by 14C matching at 11,871-9900 BP (9922–7951 BC) with an uncertainty of ±20 yr (Kromer and Spurk 1998). With these new chronologies the 14C calibration curve can now be corrected, eliminating the discrepancy in the dating of the Younger Dryas/Preboreal transition between the proxy data of the GRIP and GISP ice cores (Johnsen et al. 1992; Taylor et al. 1993), the varve chronology of Lake Gościąż (Goslar et al. 1995) and the pine chronology (Becker, Kromer and Trimborn 1991).

scholarly journals A major hydrobiological change in Dasht-e Arjan Wetland (southwestern Iran) during the late glacial – early Holocene transition revealed by subfossil chironomids

2019 ◽  
Vol 56 (8) ◽  
pp. 848-856
Author(s):  
Cyril Aubert ◽  
Morteza Djamali ◽  
Matthew Jones ◽  
Hamid Lahijani ◽  
Nick Marriner ◽  
...  
Keyword(s):  
Lake Level ◽  
Regional Scale ◽  
Younger Dryas ◽  
Late Glacial ◽  
Early Holocene ◽  
Geochemical Data ◽  
The Holocene ◽  
Chironomus Plumosus ◽  
Subfossil Chironomids ◽  
Southwestern Iran

The late glacial – early Holocene transition is a key period in the earth’s history. However, although this transition is well studied in Europe, it is not well constrained in the Middle East and palaeohydrological records with robust chronologies remain scarce from this region. Here we present an interesting hydrobiological record showing a major environmental change occurring in the Dasht-e Arjan Wetland (southwestern Iran, near to Persepolis) during the late glacial – early Holocene transition (ca. 11 650 years cal BP). We use subfossil chironomids (Insecta: Diptera) as a proxy for hydrological changes and to reconstruct lake-level fluctuations. The Arjan wetland was a deep lake during the Younger Dryas marked by a dominance of Chironomus plumosus/anthracinus-type, taxa adapted to anoxic conditions of deep waters. At the beginning of the Holocene, a drastic decrease (more than 80% to less than 10%) of Chironomus plumosus/anthracinus-type, combined with diversification of littoral taxa such as Polypedilum nubeculosum-type, Dicrotendipes nervosus-type, and Glyptotendipes pallens-type, suggests a lake-level decrease and a more vegetalized aquatic environment. We compare and contrast the chironomid record of Arjan with a similar record from northwestern Iran. The palaeoclimatic significance of the record, at a local and regional scale, is subsequently discussed. The increase in Northern Hemisphere temperatures, inferred by geochemical data from NGRIP, at the beginning of the Holocene best explains the change from the Younger Dryas highstand to early Holocene lowstand conditions in the Dasht-e Arjan wetland. However, a contribution of the meltwater inflow from small local glaciers in the catchment basin is not excluded.

Stratigraphy and paleolimnologic record of lower Holocene sediments in northern Lake Huron and Georgian Bay

1994 ◽  
Vol 31 (11) ◽  
pp. 1586-1605 ◽  
Author(s):  
David K. Rea ◽  
Theodore C. Moore Jr. ◽  
C. F. Michael Lewis ◽  
Larry A. Mayer ◽  
David L. Dettman ◽  
...  
Keyword(s):  
Seismic Reflection ◽  
Lake Level ◽  
Younger Dryas ◽  
Lake Huron ◽  
Early Holocene ◽  
Georgian Bay ◽  
Ice Cap ◽  
Lake Algonquin ◽  
Seismic Reflectors ◽  
Cold Lakes

Seismic reflection profiling and piston coring identified seismic reflectors in northern Lake Huron and Georgian Bay linked with unconformities caused by at least six reductions in lake level. In ascending stratigraphic order, these lowstands occurred at about 11 200 BP, associated with the Kirkfield outlet from early Lake Algonquin; 10 200 – 9900 BP, associated with the post-Algonquin lake level fall; 9800 – 9050 BP, the most extreme lowstand, associated with the main Stanley – Hough draw down; and 7800 – 7450 BP. The concomitant highstands are Lake Algonquin, from about 11 200 – 10 200 BP; early Lake Mattawa, between 9600 and 9350 BP; the main Mattawa phase, 9050–7800 BP; and the Nipissing highstand, at about 4700 BP. Isotopic and paleoecological data show that all of the lowstands are characterized by cold, dilute, and isotopically very light (< −20‰) waters from the melting Laurentian ice cap. Highstands, on the other hand, are characterized by higher dissolved solid concentrations and a much smaller meltwater component. Oxygen isotope values of the waters in these lakes were −15 to −17‰ in Lake Algonquin, −13 to −14‰ for the early and middle Mattawa stages, −9 to −8‰ for the main Mattawa stage, and −7‰ for modern waters. This association of lowstands and not highstands with isotopically light waters is a new contribution to early Holocene hydrology of the Great Lakes. The Younger Dryas cool episode is coeval with the Lake Algonquin highstand and a younger cool episode is generally coeval with the Mattawa highstand. This supports the hypothesis of C.F.M. Lewis and T.W. Anderson that these large cold lakes were responsible for regional cooling during the early Holocene.

scholarly journals Paleohydrological Changes in Jura (France), and Climatic Oscillations around the North Atlantic from Allerød to Preboreal

2007 ◽  
Vol 49 (3) ◽  
pp. 401-408 ◽  
Author(s):  
Michel Magny
Keyword(s):  
Lake Level ◽  
Environmental Changes ◽  
Greenland Ice Sheet ◽  
Climatic Changes ◽  
Early Holocene ◽  
Oceanic Circulation ◽  
Cool Period ◽  
Climatic Oscillations ◽  
The North ◽  
Swiss Lake

ABSTRACTRegional palaeohydroiogical changes recorded in the Jura lakes, France, have led to a tentative reconstruction of a fine-scale pattern of climatic changes from Allerød to the early Holocene. The Younger Dryas (YD) can be subdivided into three parts: after a first wet phase, this cool period was characterized by increasing dryness; a short rise in lake level developed during its last part. Moreover, the YD was preceded and followed by two short rises in lake-level, which interrupted the lake-level lowerings developing during the Allerød and the Preboreal. Climatic oscillations reconstructed in Jura appear to be in phase with glacier and tree-limit movements in the Alps, with fluctuations in oxygen-isotope records from the Swiss lakes and the Greenland ice sheet, and with climatic oscillations recorded in the Norwegian Sea. Other correlations between (1) these climatic oscillations, (2)14C plateaux recorded in Swiss lake sequences, and (3) fluctuations in the residual ∆14C, support a correlation between regional palaeohydroiogical changes defined in Jura and broad-scale climatic oscillations; they also support the existence of a link between climatic changes in Western and Central Europe and oceanic circulation. Moreover, as working hypothesis, these correlations suggest high-precision timing for the climatic and environmental changes occurring during the early Holocene.

Younger Dryas to early Holocene (12.9 to 8.1 ka) limnological and hydrological change at Barley Lake, California (northern California Coast Range)

2021 ◽  
pp. 1-15
Author(s):  
Jenifer A. Leidelmeijer ◽  
Matthew E.C. Kirby ◽  
Glen MacDonald ◽  
Joseph A. Carlin ◽  
Judith Avila ◽  
...  
Keyword(s):  
Climate Change ◽  
Lake Level ◽  
Global Climate ◽  
Younger Dryas ◽  
Winter Precipitation ◽  
Early Holocene ◽  
Lake Productivity ◽  
Radiocarbon Dates ◽  
Lower Productivity ◽  
Abrupt Shifts

Abstract Paleoperspectives of climate provide important information for understanding future climate, particularly in arid regions such as California, where water availability is uncertain from year to year. Here, we present a record from Barley Lake, California, focusing on the interval spanning the Younger Dryas (YD) to the early Holocene (EH), a period of acute and rapid global climate change. Twelve radiocarbon dates constrain the timing between 12.9 and 8.1 ka. We combine a variety of sediment analyses to infer changes in lake productivity, relative lake level, and runoff dynamics. In general, the lake is characterized by two states separated by a <200-year transition: (1) a variably deep, lower-productivity YD lake; and (2) a two-part variably shallow, higher-productivity EH lake. Inferred EH winter-precipitation runoff reveals dynamic multidecadal-to-centennial-scale variability, in agreement with the EH lake-level data. The Barley Lake archive captures both hemispheric and regional signals of climate change across the transition, suggesting a role for both ocean-atmosphere and insolation forcing. Our paleoperspective emphasizes California's sensitivity to climate change and how that change can generate abrupt shifts in limnological regimes.

Hydrological changes in the European midlatitudes associated with freshwater outbursts from Lake Agassiz during the Younger Dryas event and the early Holocene

2004 ◽  
Vol 61 (2) ◽  
pp. 181-192 ◽  
Author(s):  
Michel Magny ◽  
Carole Bégeot
Keyword(s):  
Lake Level ◽  
Thermohaline Circulation ◽  
Younger Dryas ◽  
Early Holocene ◽  
Last Deglaciation ◽  
Lake Agassiz ◽  
Westerly Jet ◽  
Cyclonic Track ◽  
Climate Cooling ◽  
Younger Dryas Event

Recent studies of lake-level fluctuations during the last deglaciation in eastern France (Jura Mountains and Pre-Alps) and on the Swiss Plateau show distinct phases of higher water level developing at the beginning and during the latter part of Greenland Stade 1 (i.e. Younger Dryas event) and punctuating the early Holocene period at 11,250–11,050, 10,300–10,000, 9550–9150, 8300–8050, and 7550–7250 cal yr B.P. The phases at 11,250–11,050 and 8300–8050 cal yr B.P. appear to be related to the cool Preboreal Oscillation and the 8200 yr event assumed to be associated with deglaciation events. A comparison of this mid-European lake-level record with the outbursts from proglacial Lake Agassiz in North America suggests that, between 13,000 and 8000 cal yr B.P. phases of positive water balance were the response in west-central Europe to climate cooling episodes, which were induced by perturbation of the thermohaline circulation due to sudden freshwater releases to oceans. This probably was in response to a southward migration of the Atlantic Westerly Jet and its associated cyclonic track. Moreover, it is hypothesized that, during the early Holocene, varying solar activity could have been a crucial factor by amplifying or reducing the possible effects of Lake Agassiz outbursts on the climate.

Early-Holocene climatic oscillations recorded by lake-level fluctuations in west-central Europe and in central Italy

2007 ◽  
Vol 26 (15-16) ◽  
pp. 1951-1964 ◽  
Author(s):  
Michel Magny ◽  
Boris Vannière ◽  
Jacques-Louis de Beaulieu ◽  
Carole Bégeot ◽  
Oliver Heiri ◽  
...  
Keyword(s):  
Central Europe ◽  
Lake Level ◽  
Central Italy ◽  
Early Holocene ◽  
Climatic Oscillations ◽  
Lake Level Fluctuations ◽  
West Central

Rock varnish record of the African Humid Period in the Lake Turkana basin of East Africa

The Holocene ◽  
2021 ◽  
pp. 095968362110116
Author(s):  
Tanzhuo Liu ◽  
Christopher J Lepre ◽  
Sidney R Hemming ◽  
Wallace S Broecker
Keyword(s):  
East Africa ◽  
Lake Level ◽  
Drainage System ◽  
Early Holocene ◽  
Lake Turkana ◽  
Moisture Condition ◽  
Turkana Basin ◽  
Rock Varnish ◽  
Geomorphic Features ◽  
Humid Period

Rock varnish is a manganiferous dark coating accreted on subaerially exposed rocks in drylands. It often contains a layered microstratigraphy that records past wetness variations. Varnish samples from latest Pleistocene and Holocene geomorphic features in the Lake Turkana basin, East Africa display a regionally replicable microstratigraphy record of Holocene millennial-scale wetness variability and a broad interval of wetter conditions during the African Humid Period (AHP). Three major wet pulses in the varnish record occurred during the generally wet interval of the early Holocene (11.5–8.5 ka) when the lake attained its maximum high stand (MHS) at 455–460 m. A >23 m drop from the MHS occurred between 8.5 and 8 ka. Subsequently two additional wet pulses occurred during the early to middle Holocene (8–5 ka) when the lake occupied its secondary high stand at 445 m. Collectively, these five wet phases represent an extended wet interval coincident with the AHP in the region. One moderate wet phase occurred during the subsequent climatic transition from the humid to arid regime (5–4.3 ka) after the lake level dropped rapidly from 445 m to <405 m. Five minor wet phases took place during the overall arid period of the late Holocene (4.3–0 ka) when the lake level oscillated below 405 m. These findings indicate that the AHP terminated rapidly around 5 ka in the Turkana basin in terms of lake level drop, but the regional shift in relative humidity from the AHP mode to its present-day condition lagged for about 700 years until 4.3 ka, hinting at a gradual phasing out in terms of moisture condition. These findings further suggest that Lake Turkana overflowed intermittently into the Nile drainage system through its topographic sill at 455–460 m during the early Holocene and has become a closed-basin lake thereafter for the past 8 ky.

Recurrent outburst floods and explosive volcanism during the Younger Dryas–Early Holocene deglaciation in south Iceland: evidence from a lacustrine record

2021 ◽  
Author(s):  
Áslaug Geirsdóttir ◽  
Gifford H. Miller ◽  
David J. Harning ◽  
Hrafnhildur Hannesdóttir ◽  
Thor Thordarson ◽  
...  
Keyword(s):  
Younger Dryas ◽  
Explosive Volcanism ◽  
Early Holocene ◽  
Outburst Floods
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