Seasonal origin of the thermal maxima at the Holocene and the last interglacial

AbstractPollen and spores in stratigraphic sections located between 40 and 42°S range in age from the Holocene, through much of the Llanquihue Glaciation, to the last interglaciation. Chronology of the stratigraphy derives from some 35 14C ages and the age relations of Llanquihue Drift and related deposits. Q-Mode, rotated, principal-components analysis of four key pollen records covering the last interglacial-glacial cycle resulted in four leading components: Nothofagus dombeyi type, Gramineae, Weinmannia-Fitzroya type, and Myrtaceae. Analysis emphasizes interaction between the first two components. Loadings of Gramineae during the interglaciation are high, unlike the Holocene; Weinmannia-Fitzroya-type loadings, prominent in the Holocene, are negligible during the interglaciation. N. dombeyi type is the primary component during Llanquihue Glaciation; it becomes modified by increases of Gramineae sometime after 31,000 and before 14,000 yr B.P. and of Myrtaceae later. The Myrtaceae with Weinmannia-Fitzroya type also registers some activity around 42,000 yr B.P. Fluctuations in the belt of westerly winds, reflecting changing meteorological conditions in polar latitudes, are suggested by these data. With the belt located farther south than it is today, interglacial climate was much drier and warmer than during the Holocene; more northerly displacement of the belt obtained when climate was colder during Llanquihue Glaciation. Evidence from comparable latitudes in the Southern Hemisphere points toward a synchrony of major climatic events indicating harmonious fluctuations in the position of the westerlies.

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Sensitivity of Red Sea circulation to sea level and insolation forcing during the last interglacial

Climate of the Past Discussions ◽

10.5194/cpd-7-1195-2011 ◽

2011 ◽

Vol 7 (2) ◽

pp. 1195-1233 ◽

Cited By ~ 3

Author(s):

G. Trommer ◽

M. Siccha ◽

E. J. Rohling ◽

K. Grant ◽

M. T. J. van der Meer ◽

...

Keyword(s):

Sea Level ◽

Red Sea ◽

Planktonic Foraminifera ◽

Gulf Of Aden ◽

Last Interglacial ◽

The Holocene ◽

Circulation Mode ◽

Monsoon Strength ◽

Mis 5E ◽

Mis 5

Abstract. This study investigates the response of Red Sea circulation to sea level and insolation changes during termination II and across the last interglacial, in comparison with termination I and the Holocene. Sediment cores from the central and northern part of the Red Sea were investigated by micropaleontological and geochemical proxies. The recovery of the planktonic foraminiferal fauna following high salinities during MIS 6 took place at similar sea-level stand (~50 m below present day), and with a similar species succession, as during termination I. This indicates a consistent sensitivity of the basin oceanography and the plankton ecology to sea-level forcing. Based on planktonic foraminifera, we find that increased water exchange with the Gulf of Aden especially occurred during the sea-level highstand of interglacial MIS 5e. From MIS 6 to the peak of MIS 5e, northern Red Sea SST increased from 21 °C to 25 °C, with about 3 °C of this increase taking place during termination II. Changes in planktonic foraminiferal assemblages indicate that the development of the Red Sea oceanography during MIS 5 was strongly determined by insolation and monsoon strength. The SW Monsoon summer circulation mode was enhanced during the termination, causing low productivity in northern central Red Sea core KL9, marked by high abundance of G. sacculifer, which – as in the Holocene – followed summer insolation. Core KL11 records the northern tip of the intruding intermediate water layer from the Gulf of Aden and its planktonic foraminifera fauna shows evidence for elevated productivity during the sea-level highstand in the southern central Red Sea. By the time of MIS 5 sea-level regression, elevated organic biomarker BIT values suggest denudation of soil organic matter into the Red Sea and high abundances of G. glutinata, and high reconstructed chlorophyll-a values, indicate an intensified NE Monsoon winter circulation mode. Our results imply that the amplitude of insolation fluctuations, and the resulting monsoon strength, strongly influence the Red Sea oceanography during sea-level highstands by regulating the intensity of water exchange with the Gulf of Aden. These processes are responsible for the observation that MIS 5e/d is characterized by higher primary productivity than the Holocene.

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High-resolution mineral dust and sea ice proxy records from the Talos Dome ice core

Climate of the Past ◽

10.5194/cp-9-2789-2013 ◽

2013 ◽

Vol 9 (6) ◽

pp. 2789-2807 ◽

Cited By ~ 18

Author(s):

S. Schüpbach ◽

U. Federer ◽

P. R. Kaufmann ◽

S. Albani ◽

C. Barbante ◽

...

Keyword(s):

Southern Ocean ◽

Sea Ice ◽

Ross Sea ◽

Transport Model ◽

Mineral Dust ◽

Ice Core ◽

Ice Cores ◽

Last Interglacial ◽

The Holocene ◽

Proxy Records

Abstract. In this study we report on new non-sea salt calcium (nssCa2+, mineral dust proxy) and sea salt sodium (ssNa+, sea ice proxy) records along the East Antarctic Talos Dome deep ice core in centennial resolution reaching back 150 thousand years (ka) before present. During glacial conditions nssCa2+ fluxes in Talos Dome are strongly related to temperature as has been observed before in other deep Antarctic ice core records, and has been associated with synchronous changes in the main source region (southern South America) during climate variations in the last glacial. However, during warmer climate conditions Talos Dome mineral dust input is clearly elevated compared to other records mainly due to the contribution of additional local dust sources in the Ross Sea area. Based on a simple transport model, we compare nssCa2+ fluxes of different East Antarctic ice cores. From this multi-site comparison we conclude that changes in transport efficiency or atmospheric lifetime of dust particles do have a minor effect compared to source strength changes on the large-scale concentration changes observed in Antarctic ice cores during climate variations of the past 150 ka. Our transport model applied on ice core data is further validated by climate model data. The availability of multiple East Antarctic nssCa2+ records also allows for a revision of a former estimate on the atmospheric CO2 sensitivity to reduced dust induced iron fertilisation in the Southern Ocean during the transition from the Last Glacial Maximum to the Holocene (T1). While a former estimate based on the EPICA Dome C (EDC) record only suggested 20 ppm, we find that reduced dust induced iron fertilisation in the Southern Ocean may be responsible for up to 40 ppm of the total atmospheric CO2 increase during T1. During the last interglacial, ssNa+ levels of EDC and EPICA Dronning Maud Land (EDML) are only half of the Holocene levels, in line with higher temperatures during that period, indicating much reduced sea ice extent in the Atlantic as well as the Indian Ocean sector of the Southern Ocean. In contrast, Holocene ssNa+ flux in Talos Dome is about the same as during the last interglacial, indicating that there was similar ice cover present in the Ross Sea area during MIS 5.5 as during the Holocene.

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Comparison of the amount of rainfall between the Eemian and the Holocene and the turbulent transition to the last interglacial period recorded in freshwater tufas from Central Spain

Quaternary International ◽

10.1016/j.quaint.2012.08.011 ◽

2012 ◽

Vol 279-280 ◽

pp. 121-122

Author(s):

David Domínguez-Villar

Keyword(s):

Interglacial Period ◽

Last Interglacial ◽

Central Spain ◽

The Holocene ◽

Turbulent Transition ◽

Last Interglacial Period

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Holocene and Last Interglacial cloudiness in eastern Baffin Island, Arctic CanadaThis article is one of a series of papers published in this Special Issue on the theme Polar Climate Stability Network.GEOTOP Publication 2008-0027.

Canadian Journal of Earth Sciences ◽

10.1139/e08-053 ◽

2008 ◽

Vol 45 (11) ◽

pp. 1221-1234 ◽

Cited By ~ 9

Author(s):

Bianca Fréchette ◽

Anne de Vernal ◽

Pierre J.H. Richard

Keyword(s):

Air Temperature ◽

Growing Season ◽

Dwarf Shrub ◽

Interglacial Period ◽

Vegetation Changes ◽

Baffin Island ◽

Last Interglacial ◽

The Holocene ◽

Growing Season Length ◽

Shrub Tundra

This study presents Last Interglacial and Holocene vegetation and climate changes at Fog Lake (67°11′N, 63°15′W) on eastern Baffin Island, Arctic Canada. The vegetation cover is reported as vegetation structural types (or biomes). July air temperature and sunshine during the growing season (June–July–August–September) were reconstructed from pollen assemblages using the modern analogue technique. The vegetation of the Last Interglacial period evolved from a prostrate dwarf-shrub tundra to a low- and high-shrub tundra vegetation. The succession of four Arctic biomes was distinguished from the Last Interglacial sediments, whereas only one Arctic biome was recorded in the Holocene sediments. From ca. 8300 cal. years BP to present, hemiprostrate dwarf-shrub tundra occupied the soils around Fog Lake. During the Last Interglacial, growing season sunshine was higher than during the Holocene and July air temperature was 4 to 5 °C warmer than present. A principal component analysis helped in assessing relationship between floristic gradients and climate. The major vegetation changes through the Last Interglacial and Holocene were driven by July air temperature variations, whereas the minor, or subtle, vegetation changes seem rather correlated to September sunshine. This study demonstrates that growing season sunshine conditions can be reconstructed from Arctic pollen assemblages, thus providing information on feedbacks associated with cloud cover and summer temperatures, and therefore growing season length.

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Comparison of the vegetational and hydroclimatic evolution during the Holocene and Last Interglacial in western Iran

Quaternary International ◽

10.1016/j.quaint.2012.08.1565 ◽

2012 ◽

Vol 279-280 ◽

pp. 467-468

Author(s):

Lora Stevens

Keyword(s):

Last Interglacial ◽

Western Iran ◽

The Holocene

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Lower oceanic <i>δ</i><sup>13</sup>C during the last interglacial period compared to the Holocene

Climate of the Past ◽

10.5194/cp-17-507-2021 ◽

2021 ◽

Vol 17 (1) ◽

pp. 507-528

Author(s):

Shannon A. Bengtson ◽

Laurie C. Menviel ◽

Katrin J. Meissner ◽

Lise Missiaen ◽

Carlye D. Peterson ◽

...

Keyword(s):

North Atlantic ◽

Interglacial Period ◽

Oceanic Circulation ◽

Last Interglacial ◽

The Holocene ◽

Last Interglacial Period ◽

Significant Difference ◽

Depth Extent ◽

Global Carbon

Abstract. The last time in Earth's history when high latitudes were warmer than during pre-industrial times was the last interglacial period (LIG, 129–116 ka BP). Since the LIG is the most recent and best documented interglacial, it can provide insights into climate processes in a warmer world. However, some key features of the LIG are not well constrained, notably the oceanic circulation and the global carbon cycle. Here, we use a new database of LIG benthic δ13C to investigate these two aspects. We find that the oceanic mean δ13C was ∼ 0.2 ‰ lower during the LIG (here defined as 125–120 ka BP) when compared to the Holocene (7–2 ka BP). A lower terrestrial carbon content at the LIG than during the Holocene could have led to both lower oceanic δ13C and atmospheric δ13CO2 as observed in paleo-records. However, given the multi-millennial timescale, the lower oceanic δ13C most likely reflects a long-term imbalance between weathering and burial of carbon. The δ13C distribution in the Atlantic Ocean suggests no significant difference in the latitudinal and depth extent of North Atlantic Deep Water (NADW) between the LIG and the Holocene. Furthermore, the data suggest that the multi-millennial mean NADW transport was similar between these two time periods.

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Differences in water mass geometry in the Atlantic Ocean during the Holocene and the last interglacial period

10.7185/gold2021.7951 ◽

2021 ◽

Author(s):

Julia Gottschalk ◽

Frerk Pöppelmeier ◽

Patrick Blaser ◽

Marcus Gutjahr ◽

Sophia Hines ◽

...

Keyword(s):

Atlantic Ocean ◽

Water Mass ◽

Interglacial Period ◽

Last Interglacial ◽

The Holocene ◽

Last Interglacial Period

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Holocene Coral Reef Terraces and Coseismic Uplift of Huon Peninsula, Papua New Guinea

Quaternary Research ◽

10.1006/qres.1993.1070 ◽

1993 ◽

Vol 40 (2) ◽

pp. 177-188 ◽

Cited By ~ 67

Author(s):

Y. Ota ◽

J. Chappell ◽

R. Kelley ◽

N. Yonekura ◽

E. Matsumoto ◽

...

Keyword(s):

Coral Reef ◽

Papua New Guinea ◽

Late Quaternary ◽

Mass Movement ◽

New Guinea ◽

Last Interglacial ◽

The Holocene ◽

Fluvial Terraces ◽

Uplift Rates ◽

Recurrence Intervals

AbstractAs many as six levels of emerged Holocene coral terraces occur along 40 km of coastline on the Huon Peninsula, Papua New Guinea, recording uplift history since culmination of the postglacial transgression. The Holocene reef crest, ca. 6000 yr B.P., is tilted down to the northwest, parallel to the coast and concordant with the deformation of the last interglacial coral reef terrace, and descends from 23 to 12 m in the study area. The pattern and rate of deformation have been uniform in the late Quaternary because average uplift rates have remained the same since the last interglaciation. The Holocene terraces described here are erosional features with regressive encrusting corals, developed upon the Holocene transgressive reef. The multiple levels represent episodic, probably coseismic uplift, which has occurred repeatedly in the last ca. 6000 yr. Significant longshore variation in the age of the lowest terrace, from 1700 to 2500 yr B.P., suggests independent coseismic uplift on different sectors of the coast. This is supported by age-height relationships of the higher Holocene terraces. Nonlinear uplift during the Holocene, with recurrence intervals increasing toward the present, is clearly recorded by the regressive terraces in each subregion. Some of the Holocene regressive terraces grade laterally into fluvial terraces capped with debris-flow deposits, probably reflecting seismically triggered mass movement.

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