Holocene Rapid Climate Change Research Articles

Rapid climate changes and human dynamics during the holocene in the eastern mediterranean (Lower Strymon Valley, northern Greece)

The study was conducted in the southern part of the lower Strymon valley, in northern Greece, and revealed up to 25 m of fluvio-lacustrine sediments deposited over the last seven millennia. This sedimentary record represents a significant opportunity for high-resolution palaeoenvironmental studies of the period from 6 to 3 ka cal BP linked to land use and climate change. The results of geophysical investigations, multi-proxy sedimentological (grain size, magnetic susceptibility, loss-on-ignition), pollen and NPP analyses, based on high-precision radiocarbon dating enabled reconstruction of past landscapes as well as a comprehensive discussion of anthropogenic responses and their impact on the vegetation cover, especially during periods with well-known Holocene Rapid Climate Change events (5.6, 4.2 and 3.2 ka cal BP).During the 7–5.7 ka cal BP corresponding to the Late and Final Neolithic, wet conditions created an extended lake surrounded by the densely wooded Strymon watershed, followed by a shift to a shallower lake environment that lasted until ca. 4.5 ka cal BP. The continuous presence of anthropogenic taxa suggests the persistence of human activities even in the absence of formally recognized sites, suggesting the relocation of settlements. The first signs of human disturbance of the landscape at regional scale occurred toward 5.2 ka cal BP (onset of the Early Bronze Age). The so-called « 4.2 ka BP event », which coincided with the end of the Early Bronze Age and the transition to the Middle Bronze Age, is divided into three distinct periods (4.35–4.1, 4.1–3.95 and 3.95–3.75 ka cal BP). The first corresponds to gradual aridification before a period with severe dry conditions that marks a tipping point toward wetland contraction. From this period on, diversification, and multiplication of anthropogenic species including Olea, Juglans and Castanea reflect a global trend toward cultural landscapes. The later periods are characterized by dramatic climatic change around 3.2–3 ka cal BP, at the end of Late Bronze Age, and increasing impacts of agro-pastoral activities and forest clearing starting at the beginning of Antiquity, around 2.8 ka cal BP (Thracian period). After the 4.2 ka cal BP event and we suggest that climatic adversity may have acted as a stimulus to innovation and relocation rather than retarding societal development in the region. To conclude, environmental factors in the lower Strymon valley were not sufficient on their own to trigger a social crisis similar to that mentioned in the Middle East.

Dating Neolithic rubble layers from Ba'ja and Basta sites in southern Jordan using luminescence

There is considerable evidence of widespread damage in the 7th millennium habitation sites across Jordan. The origins of this damage are unknown, but the most widely accepted hypothesis associates the resulting rubble and gravel deposits with the Holocene Rapid Climate Change. One way of testing the various hypotheses is to provide a more reliable chronology for the event(s) in question. In this study, we used quartz OSL and feldspar IRSL signals to date accumulative rubble layers at two archaeological sites in Southern Jordan; Ba'ja and Basta. By comparison with the OSL ages, the IRSL ages demonstrate that most of the quartz samples were sufficiently well bleached at deposition to provide accurate ages. Quartz ages show that deposition of the rubble layers took place in different episodes starting around 8.5 ka and 6.0 ka. Ages from Ba'ja site agree with the archaeological expectations of time of deposition. However, the results from Basta are younger than the archaeological expectations, which are based mainly on architectural style and stratigraphy.

High-resolution geochemical (μXRF) and palynological analyses for climatic and environmental changes in lake sediments from Sultansazlığı Marsh (Central Anatolia) during the last 14.5 kyr

Multi-proxy analyses of Sultansazlığı Marsh sedimentary sequence covering the last ∼14.5 kyr documents climatic and environmental changes in Central Anatolia (Turkey) and can be correlated with Holocene Rapid Climate Changes (RCCs). Well-correlated geochemical compositions (μXRF), pollen and lithological analyses, together with an age-depth model, were used to determine the time intervals of cold, dry, warm, and wet conditions in Sultansazlığı. Geochemical and pollen data including Younger Dryas (YD) revealed 9 arid periods RCCs; 11.1 ka, 10.3 ka, 9.3 ka, 8.2 ka, 7.3 ka (for this study), 6.5 ka (for this study), 5.9 ka, 4.2 ka, and 2.8 ka. The analysis of glacial advance during the Lateglacial suggests that the climate was cold and wet. YD and two more hiatuses have been accurately determined from the μXRF geochemical proxies. However, YD cold period does not show severe conditions like in other areas in the world. Moreover, the other two hiatuses were clearly determined between Early- Middle and inside the Middle Holocene. In general, the period after 9.8 ka indicates warming conditions towards the recent with some fluctuations compared to an overall trend of the climate.

RETRACTED ARTICLE:Monsoon climate change based on cloud data and numerical simulation of basketball

Holocene is an important period for the evolution of human civilization and the study of the relationship between climate change and the development of human society. In the Asian monsoon region, monsoon climate change is an important factor affecting social culture and the change of historical dynasties. Therefore, the evolution of Holocene East Asian monsoon and the abrupt change of Millennium scale are the focus of scientific research. Holocene, as a typical interglacial period, is characterized by a series of abrupt climatic events on a millennium scale, such as Holocene rapid climate change (RCC) and high latitude bond events. In this paper, the quality of point cloud data and the quality of point cloud processing and rendering algorithm can be indirectly evaluated by evaluating the image quality of point cloud data directly drawn, so as to study the monsoon climate change. This paper also analyzes the origin of basketball, which originated in Massachusetts. It was invented by James Naismith, a Christian in Springfield, in 1891. It was introduced to China’s Tianjin YMCA in 1895. In 1896, the Tianjin YMCA held a basketball game performance. As a result, modern basketball officially began in China and gradually spread to the whole country extension. Basketball has been invented for more than 100 years. This paper analyzes and simulates the kinematic data of basketball players in the four stages of holding the ball preparation stage, kicking off stage, shooting in the air stage, and landing buffer stage, such as the movement time, joint angle change, and speed change. It promotes the improvement of basketball players’ shooting skills.

Holocene rapid climate changes and ice-rafting debris events reflected in high-resolution European charcoal records

In contrast to marked climate change across glacial-interglacial cycles, the Holocene epoch represents a relatively warm, stable interval. However, on finer temporal scales, it too has experienced both gradual and rapid changes in climate. In the North Atlantic region, many rapid climate changes (RCCs) coincide with ice-rafted debris (IRD) or Bond events, which are associated with cooling and suggested to occur with periodicities of 1370 ± 500 years. Given that climate is a dominant control of fire activity, regulating both vegetation productivity and fuel moisture, this study investigated the linkage between Holocene fire, IRD episodes and associated RCCs in seven high-resolution charcoal records distributed across Europe. Results show low-frequency fire periodicities of 500–600 years, 900–1400 and 2400 years that occurred simultaneously across northern and mid-latitude Europe, suggesting that regional fire disturbance responded to large-scale climate drivers. The 900–1400 year periodicity is most common among sites and of similar frequency to IRD episodes, potentially reflecting a connection between mechanisms regulating IRD flux in the North Atlantic and wildfire activity in Europe. Although the data indicate some spatial variability in fire induced by local drivers (such as vegetation and human impact) during RCC events associated with IRD peaks, broad-scale patterns are discernible. Specifically, Northern Europe burned more during the 10.2, 9.4, 8.2, 5.9 and 4.2 kiloannum before present (ka) RCC events when climate was drier, and less during the 2.9 and 1.4 ka events when climate was moister. In contrast, in mid-latitude Europe, a higher incidence of fire is documented at 8.2 and 1.4 ka when climate was drier and a lower incidence of fire is associated with moister conditions at 10.2, 9.4 and 2.9 ka. Spatial heterogeneity is evident in mid-latitude Europe during the 5.9, 4.2 and 0.4 ka events. These spatially explicit sub-continental scale differences in fire activity may be related to differences in moisture availability resulting from shifts in associated atmospheric circulation patterns.

Ocean-atmosphere interactions as drivers of mid-to-late Holocene rapid climate changes: Evidence from high-resolution stalagmite records at DeSoto Caverns, Southeast USA

Oxygen and carbon isotope time-series derived from an actively growing aragonitic stalagmite in DeSoto Caverns exhibit with unusual clarity rapid hydroclimate changes in the mid-to-late Holocene. Data consist of 1884 δ18O and δ13C determinations whose chronology is anchored on 35 230Th/234U absolute dates in the interval 6.0–1.1 cal ka BP. Exceptional 18O and 13C-enrichments centered at 4.8 ± 0.14 cal ka BP likely represent the imprints of a severe drought. Isotope cycles from 4.7 to 1.3 cal ka BP, exhibit a dominant periodicity of 68 ± 4 yrs. A gradual cooling trend of ∼0.6 °C/103 yrs is attributed to a declining seasonal contrast in insolation. The synchronicity of the mega-drought in the Southeast US with the (1) termination of the African Humid Period; (ii) abrupt reduction of the North Atlantic Deep Water production, and (iii) rapid sea-ice expansion in the polar regions of both Hemispheres testifies to the global extent and rapidity of the “5 ka” event and points to the North Atlantic Deep Water variability as the likely controlling factor. The multidecadal cycles are consistent with alternating dry and wet summers occurring during a long-term switch in the seasonal rainfall amount dominance from winter to summer. The periodic summer droughts in the Southeast US support climate models that predict profound hydroclimate changes in the late Holocene governed by the Atlantic Multidecadal Oscillation. The relatively short and rapid hydroclimate phase transitions documented in this study introduce a complication in the correlation of late Holocene drought events that had significant societal impacts.

Fluvial response to the last Holocene rapid climate change in the Northwestern Mediterranean coastlands

The variability of fluvial activity in the Northwestern Mediterranean coastal lowlands and its relationship with modes of climate change were analysed from the late 9th to the 18th centuries CE. Geochemical analyses were undertaken from a lagoonal sequence and surrounding sediments in order to track the fluvial inputs into the lagoon. An index based on the K/S and Rb/S ratios was used to evidence the main periods of fluvial activity. This index reveals that the Medieval Climate Anomaly (MCA) was a drier period characterized by a lower fluvial activity, while the Little Ice Age (LIA) was a wetter period with an increase of the river dynamics. Three periods of higher than average fluvial activity were evidenced at the end of the first millennium CE (ca. 900–950calyrCE), in the first half of the second millennium CE (ca. 1150–1550calyrCE), and during the 1600s–1700s CE (ca. 1650–1800calyrCE). The comparison of these fluvial periods with other records of riverine or lacustrine floods in Spain, Italy, and South of France seems to indicate a general increase in fluvial and flood patterns in the Northwestern Mediterranean in response to the climate change from the MCA to the LIA, although some episodes of flooding are not found in all records. Besides, the phases of higher than average fluvial dynamics are in good agreement with the North Atlantic cold events evidenced from records of ice-rafted debris. The evolution of fluvial activity in the Northwestern Mediterranean coastlands during the last millennium could have been driven by atmospheric and oceanic circulation patterns.

Terrestrial and aquatic ecosystem responses to early Holocene rapid climate change (RCC) events in the South Carpathian Mountains, Romania

As demonstrated by an increasing number of palaeoclimatic and palaeoecological studies, rapid climate change events (RCCs) occurred frequently in the Holocene and their timing correlates well in the European records. Changes in vegetation composition and environmental conditions were significant during these RCC events. In this study we use high resolution pollen, stomata, micro- and macrocharcoal, macrofossil, siliceous algae, biogenic silica and organic content analyses from two alpine lake sediments (Lake Brazi, 1740 m a.s.l.; Lake Gales, 1990 m a.s.l.) in the Retezat Mts, South Carpathian Mountains, Romania. Our aim is to study ecosystem responses to RCCs between 12,000 and 7000 cal yr BP using high-resolution proxy analyses of the relevant sediment sections. We detected several significant changes in the terrestrial vegetation composition and aquatic ecosystems in case of both lakes. Complex ecosystem responses were found in connection with the early Holocene RCC intervals. Most prominently, the 10.2 ka climatic change likely fostered the extinction of Larix decidua from the shore of Lake Brazi, while climatic change during the 8.2 ka event facilitated the establishment of Carpinus betulus in the lower deciduous mixed oak forests, due to decreasing growing season temperatures, frequent summer droughts and associated recurrent fire events. Taken together, most of the significant pollen compositional changes reflected the periodic spread of pioneer deciduous tree taxa (mainly Fraxinus excelsior and Corylus avellana) during the early Holocene RCCs. In all cases, this change was connectable to increased regional fire activity and the temporary increase of herbs. The most significant change in the lake-ecosystems was often the short-lived spread of various planktonic diatom species, mainly the members of genus Aulacoseira. Sudden appearance and large-scale percentage increase of these taxa suggested higher water-depth and/or intensified water turbulence.

Interactions between climate change and human activities during the early to mid-Holocene in the eastern Mediterranean basins

Abstract. This paper focuses on early Holocene rapid climate change (RCC) records in the Mediterranean zone, which are under-represented in continental archives (9.2 to 8.2 ka events) and on their impact on prehistoric societies. This lack of data handicaps the general interpretation of climate impacts on human societies, which flourished in recent years. Key questions remain about the impact of early Holocene cooling events on the Mediterranean climate, ecosystems and human societies. In this paper, we discuss some examples from river and lake systems from the eastern to central Mediterranean area (central Anatolia, Cyprus, northeastern and northwestern Greece) that illustrate some palaeohydrological and erosion variations that modified the sustainability of the first Neolithic populations in this region. Results allow us to present direct land–sea correlations and to reconstruct regional long-term trends as well as millennial- to centennial-scale climatic changes. In this context, we question the socio-economic and geographical adaptation capacities of these societies (mobility, technology, economic practices, social organisation) during the “early Holocene” interval (11.7 to 8.2 ka), which corresponds partly to the Sapropel 1 deposition in the eastern Mediterranean sea.

Synchronous Environmental and Cultural Change in the Emergence of Agricultural Economies 10,000 Years Ago in the Levant.

The commonly held belief that the emergence and establishment of farming communities in the Levant was a smooth socio-economic continuum during the Pre-Pottery Neolithic (ca. 12,000-9,000 cal BP) with only rare minor disruptions is challenged by recently obtained evidence from this region. Using a database of archaeological radiocarbon dates and diagnostic material culture records from a series of key sites in the northern Levant we show that the hitherto apparent long-term continuity interpreted as the origins and consolidation of agricultural systems was not linear and uninterrupted. A major cultural discontinuity is observed in the archaeological record around 10,000 cal BP in synchrony with a Holocene Rapid Climate Change (RCC), a short period of climatic instability recorded in the Northern Hemisphere. This study demonstrates the interconnectedness of the first agricultural economies and the ecosystems they inhabited, and emphasizes the complex nature of human responses to environmental change during the Neolithic period in the Levant. Moreover, it provides a new environmental-cultural scenario that needs to be incorporated in the models reconstructing both the establishment of agricultural economy in southwestern Asia and the impact of environmental changes on human populations.

Non-linear regime shifts in Holocene Asian monsoon variability: potential impacts on cultural change and migratory patterns

Abstract. The Asian monsoon system is an important tipping element in Earth's climate with a large impact on human societies in the past and present. In light of the potentially severe impacts of present and future anthropogenic climate change on Asian hydrology, it is vital to understand the forcing mechanisms of past climatic regime shifts in the Asian monsoon domain. Here we use novel recurrence network analysis techniques for detecting episodes with pronounced non-linear changes in Holocene Asian monsoon dynamics recorded in speleothems from caves distributed throughout the major branches of the Asian monsoon system. A newly developed multi-proxy methodology explicitly considers dating uncertainties with the COPRA (COnstructing Proxy Records from Age models) approach and allows for detection of continental-scale regime shifts in the complexity of monsoon dynamics. Several epochs are characterised by non-linear regime shifts in Asian monsoon variability, including the periods around 8.5–7.9, 5.7–5.0, 4.1–3.7, and 3.0–2.4 ka BP. The timing of these regime shifts is consistent with known episodes of Holocene rapid climate change (RCC) and high-latitude Bond events. Additionally, we observe a previously rarely reported non-linear regime shift around 7.3 ka BP, a timing that matches the typical 1.0–1.5 ky return intervals of Bond events. A detailed review of previously suggested links between Holocene climatic changes in the Asian monsoon domain and the archaeological record indicates that, in addition to previously considered longer-term changes in mean monsoon intensity and other climatic parameters, regime shifts in monsoon complexity might have played an important role as drivers of migration, pronounced cultural changes, and the collapse of ancient human societies.

Seasonality variations in the Central Mediterranean during climate change events in the Late Holocene

Holocene rapid climate change (RCC) events, such as the Little Ice Age (LIA), are thought to have influenced average annual temperatures only marginally, but to have affected winter temperatures relatively strongly. With summer temperatures relatively unaffected, reconstructing climate change at a seasonal resolution is crucial to fully capture Holocene climate variability. Mediterranean climate is highly seasonal, being influenced by the subtropical high-pressure belt in summer and the mid-latitude westerlies combined with outbreaks of polar winds in winter. We identified events of high- and low-detrital input to the Gulf of Taranto (Central Mediterranean Sea), anticipated to be linked to humid and dry conditions, respectively and, thereby, potentially reflecting seasonal contrasts. These events represent the Bronze Age (BA), Roman Humid Period (RHP), Medieval Climate Anomaly (MCA), LIA and present-day, and were selected for the analysis of single specimen Globigerinoides ruber (white) carbonate chemistry (Mg/Ca, δ18O and δ13C). The dynamic range found for these parameters for the measured single individuals in the most recent interval reflects the present-day seasonal contrasts in temperature and precipitation, albeit with a bias towards the summer season. These results are compared with high-resolution (<15years/sample) Sea Surface Temperature (SST) and Bottom Water Temperature (BWT) reconstructions based on the δ18O of G. ruber (white) and Mg/Ca of benthic foraminifer Hyalinea balthica. Although the seasonal temperature contrast remains relatively stable, significant winter cooling is observed during the BA and LIA. Connections between high-latitude climate (winter conditions) and low-latitude climate (summer conditions) appear not straightforward during RCC events. This results in changes in the moisture balance, and in shifts in seasonal dominance between RCCs. During the LIA, winter-like conditions (cold and humid) prevail throughout the year. In contrast, winters are dry and cold during the BA, and are accompanied by dry and warm summers, suggesting year-round aridity and a relatively high seasonal temperature contrast. This could have had a profound impact on early agriculture in Southern Italy.

Climatically-driven impacts on sedimentation processes in the Bay of Quiberon (south Brittany, France) over the last 10,000 years

The Bay of Quiberon (NW France), which is protected by the Quiberon Peninsula, provides well-preserved sedimentary archives for high-resolution reconstruction of Holocene climate variability. Very-high-resolution seismic profiles were obtained from two Seistec boomer seismic campaigns conducted in the bay. The seismic surveys reveal the deposition of five distinct sedimentary units. This succession is correlated with radiocarbon-dated sediments sampled in a long CASQ core (MD08-3204CQ). The analysis of the sediments shows significant changes in grain size, indicating a complex series of palaeo-climate events dated at 8800, 8600, 4270, 3860, 2470 and 1060 cal. yr BP. These may be correlated with millennial timescale climate variability corresponding to the phases of Holocene rapid climate changes (RCCs), associated with negative North Atlantic Oscillation (NAO) index and usually characterized by weaker winter storms. On the contrary, periods between RCCs are characterized by the predominance of westerly winds and stormy conditions for Brittany (i.e. positive NAO). However, only storm events occurring during the RCCs have been preserved in the Bay of Quiberon. This paper aims to reconstruct the Holocene sedimentary infill of the bay, highlighting the role of episodic acceleration phases of the sea-level rise on the preservation of sedimentary archives. Thus, the Bay of Quiberon provides substantially a complete sedimentation record of the last 10,000 years characterized by a series of complex palaeo-environmental changes.

Thresholds and sensitivity of fragile Western Mediterranean landscapes during Holocene Rapid Climate Changes

Thresholds and sensitivity of fragile Western Mediterranean landscapes during Holocene Rapid Climate Changes

Fragility of Western Mediterranean landscapes during Holocene Rapid Climate Changes

In this paper we explore the evidence for Holocene Rapid Climate Changes (RCCs) in Western Mediterranean records, examining similarities and differences in the timing and nature of impacts on different components of the natural environment (vegetation, fluvial and coastal sedimentation, fire activity, soil formation). Marine, lacustrine, and fluvial archives of the Western Mediterranean (Iberian Peninsula and Northwest Africa) provide evidence for both pervasive millennial-scale climatic variability and abrupt (decadal- to centennial-scale) transitions. We focus in particular on three RCCs characterised by high-latitude cooling, glacier advances and North-Atlantic ice-rafting events: the mid-Holocene RCC interval 6–5 cal ka BP, the late-Holocene RCC interval 3.5–2.5 cal ka BP, and the historical RCC interval known as the Little Ice Age (LIA, 1300–1950 AD). Evidence from multiple records indicates wide-ranging impacts of RCCs in the Western Mediterranean region. The three RCC intervals were characterised, however, by contrasting hydrological situations in the Western Mediterranean, with prevailing dry conditions including marked aridification events during the RCC intervals 6–5 and 3.5–2.5 cal ka BP, and prevailing or recurrent wet conditions during the LIA. We examine issues of proxy sensitivity in palaeoecological and geomorphological records and evaluate examples of contrasting geomorphological responses to regional climatic triggers between humid and semi-arid sectors of the Western Mediterranean. Finally, we consider the long-term sensitivity of the region to rapid climate change, the role of threshold changes, and the extent to which this region represents a “fragile” landscape.

Using seismic facies and pollen analyses to evaluate climatically driven change in a Scottish sea loch (fjord) over the last 20 ka

Abstract Loch Sunart is a glacially over-deepened sea loch (fjord) on the west coast of Scotland, UK. The loch is divided into three sub-basins, separated by relatively shallow and narrow sills. A programme of data collection including high-resolution bathymetric sonar and sub-bottom seismic surveys were conducted in the loch as part of an investigation into the sedimentological and climatic change signatures preserved in western sea lochs since the Last Glacial Maximum. Very-high-resolution sub-bottom profiles were obtained using the SEISTEC boomer system. The seismic profiles revealed an igneous and metamorphic basement covered by a 10–70 m thick sediment sequence. Five different acoustic facies were recognized and interpreted in terms of glacial activity, ice retreat and subsequent Holocene sedimentation. These facies have been correlated to sediments sampled in a radiocarbon-dated 12 m long giant piston core (MD04-2833) acquired from the main basin of Loch Sunart. Pollen analyses conducted along the length of the core, together with 14 C dating, indicate a complex series of palaeoclimate changes in the loch. In particular, five distinct cooling events have been recognized c . 9.8, 8.2, 5.8, 1.2 cal ka BP and 771–1211 cal a BP (possibly the Little Ice Age), corresponding to phases of Holocene rapid climate change.

Flood frequencies reveal Holocene rapid climate changes (Lower Moulouya River, northeastern Morocco)

AbstractCurrent high‐resolution palaeoenvironmental records reveal short‐term Holocene coolings. One of these major Holocene rapid climate changes occurred between 3.2 and 2.7 cal. ka BP. The sensitivity of river systems vis‐à‐vis slight and short‐term Holocene climatic variations is a subject of controversy in the scientific community. In this paper, we present a 4.0 to 1.4 cal ka BP palaeoflood record from the Lower Moulouya River (northeastern Morocco) to demonstrate the high sensitivity of semiarid rivers in the southwestern Mediterranean towards Holocene environmental changes. The Lower Moulouya flood deposits are characterised by thick, well‐stratified, predominantly clayey to silty overbank fine sediments. These cohesive sediments show evidence of excellent preservation conditions against fluvial erosion and contain a continuous record of mid to late Holocene flood sequences. The Moulouya palaeoflood record can be interpreted in the context of regional and global high‐resolution proxy data, revealing a strong coupling with Holocene rapid climate changes. The centennial‐scale Moulouya palaeohydrological history will be discussed with palaeoenvironmental data from the same record (palaeomagnetics, sedimentary charcoal record, anthracological analyses, snail analyses) to generate new ideas about the mid to late Holocene hydrological cycle in the southwestern Mediterranean. The deduced features of pronounced Lower Moulouya flooding and the decreased fire recurrence during Holocene cooling remain somewhat inconsistent with the interpretation of other palaeohydrological and paleaoecological records from the southwestern Mediterranean. However, enhanced Lower Moulouya flood frequencies between 3.2 and 2.7 cal. ka BP agree with increased floodplain aggradation in other major river systems of Mediterranean North Africa. Copyright © 2009 John Wiley &amp; Sons, Ltd.

Impacts of late Holocene rapid climate changes as recorded in a macrotidal coastal setting (Mont-Saint-Michel Bay, France)

Research Article| November 01, 2009 Impacts of late Holocene rapid climate changes as recorded in a macrotidal coastal setting (Mont-Saint-Michel Bay, France) I. Billeaud; I. Billeaud 1Morphodynamique Continentale et Côtière, Université de Caen, UMR CNRS 6143, 24 rue des Tilleuls, 14000 Caen, France Search for other works by this author on: GSW Google Scholar B. Tessier; B. Tessier 1Morphodynamique Continentale et Côtière, Université de Caen, UMR CNRS 6143, 24 rue des Tilleuls, 14000 Caen, France Search for other works by this author on: GSW Google Scholar P. Lesueur P. Lesueur 1Morphodynamique Continentale et Côtière, Université de Caen, UMR CNRS 6143, 24 rue des Tilleuls, 14000 Caen, France Search for other works by this author on: GSW Google Scholar Author and Article Information I. Billeaud 1Morphodynamique Continentale et Côtière, Université de Caen, UMR CNRS 6143, 24 rue des Tilleuls, 14000 Caen, France B. Tessier 1Morphodynamique Continentale et Côtière, Université de Caen, UMR CNRS 6143, 24 rue des Tilleuls, 14000 Caen, France P. Lesueur 1Morphodynamique Continentale et Côtière, Université de Caen, UMR CNRS 6143, 24 rue des Tilleuls, 14000 Caen, France Publisher: Geological Society of America Received: 10 Apr 2009 Revision Received: 19 Jun 2009 Accepted: 30 Jun 2009 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2009 Geological Society of America Geology (2009) 37 (11): 1031–1034. https://doi.org/10.1130/G30310A.1 Article history Received: 10 Apr 2009 Revision Received: 19 Jun 2009 Accepted: 30 Jun 2009 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation I. Billeaud, B. Tessier, P. Lesueur; Impacts of late Holocene rapid climate changes as recorded in a macrotidal coastal setting (Mont-Saint-Michel Bay, France). Geology 2009;; 37 (11): 1031–1034. doi: https://doi.org/10.1130/G30310A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The impacts of rapid climate changes during the Holocene are well documented in deep oceanic and lacustrine sediments. Until now, no studies have shown the effects of rapid climate change on tidal successions in coastal wedges formed during the late Holocene transgression. Cores and very high resolution seismic data collected in Mont-Saint-Michel Bay, France, a macrotidal setting, demonstrate that rapid climate changes, with ~1500 year periodicity, are recorded in the sedimentary successions that constitute the late Holocene infill of the bay. The sedimentary expressions of rapid climate changes vary according to the different subenvironments within Mont-Saint-Michel Bay; cycles, a few meters thick, can be correlated throughout the bay, and radiocarbon dating suggests that they have a millennial time scale. The various changes reflect an increase in wave dynamics in association with Bond cold events, possibly in conjunction with long-term (1800 year periodicity) tidal cycles. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Regional fire history shows abrupt responses of Mediterranean ecosystems to centennial-scale climate change ( Olea–Pistacia woodlands, NE Morocco)

The reconstruction of regional fire history with the aid of a sedimentary charcoal record (1.4–4.0 ka cal BP) of semiarid Pistacia and Olea woodlands from NE Morocco demonstrates a high sensitivity of desert margins in the SW Mediterranean towards Rapid Climate Changes. The sedimentary charcoal record derives from alluvial archives of the Lower Moulouya River. These archives contain a centennial-scale proxy record for Mid- to Late Holocene fire histories. We analyse the charcoal data together with proxy data from the same record (palaeomagnetics, anthracological and snail analyses, palaeoflood chronology) to determine palaeoenvironmental conditions. The environmental history of the SW Mediterranean is discussed with respect to our data, and in the context of other regional palaeoenvironmental archives. We demonstrate a strong coupling of charcoal accumulation with Holocene Rapid Climate Changes. We deduce low charcoal densities and pronounced Lower Moulouya flood events in the course of Holocene cooling between 2.7 and 3.2 ka cal BP, and interpret them carefully as a fuel load limited ecosystem during a regional phase of aridity with lower mean annual rainfall but more intense precipitation patterns.

High-resolution isotope records of early Holocene rapid climate change from two coeval stalagmites of Katerloch Cave, Austria

Two coeval stalagmites from Katerloch Cave show pronounced intervals of low δ18O values around 8.2, 9.1, and 10.0kyr (all ages are reported before the year 2000 AD) and represent an inorganic U–Th dated climate archive from the southeast of the European Alps, a region where only very few well-dated climate records exist. The O isotope curves, providing near-annual resolution, allow a direct comparison to the Greenland ice core records, as temperature was the primary factor controlling the O isotopic composition of Katerloch speleothems.The 8.2kyr climate anomaly lasted about one century, from 8196 to 8100yr, with a maximum amplitude of 1.1‰ at 8175yr. The event is characterized by a rapid onset and a more gradual demise and U–Th data as well as annual lamina counting support a rapid climate change towards cooler conditions within 10–20yr. There is no strong evidence that the 8.2kyr anomaly was superimposed on a pronounced longer-term cooling episode, nor do the new data support two separate cooling events within the 8.2kyr event as reported by other studies. Our record also shows a distinct climate anomaly around 9.1kyr, which lasted 70–110yr and showed a maximum amplitude of 1.0‰, i.e. it had a similar duration and amplitude as the (central) 8.2kyr event. Compared to the 8.2kyr event, the 9.1kyr anomaly shows a more symmetrical structure, but onset and demise still occurred within a few decades only. The different progression of the 8.2 (asymmetrical) and 9.1kyr anomaly (symmetrical) suggests a fundamental difference in the trigger and/or the response of the climate system. Moreover, both stalagmites show evidence of a climate anomaly around 10.0kyr, which was of comparable magnitude to the two subsequent events.Using a well constrained modern calibration between air temperature and δ18O of precipitation for the study area and cave monitoring data (confirming speleothem deposition in Katerloch reflecting cave air temperature), a maximum cooling by ca 3°C can be inferred at 8.2 and 9.1kyr, which is similar to other estimates, e.g., from Lake Ammersee north of the Alps. The O isotopic composition of meteoric precipitation, however, is a complex tracer of the hydrological cycle and these temperature estimates do not take into account additional effects such as changes in the source area or synoptic shifts. Apart from that, the relative thickness of the seasonally controlled lamina types in the Katerloch stalagmites remains rather constant across the intervals comprising the isotopic anomalies, i.e. the stalagmite petrography argues against major shifts in seasonality during the early Holocene climate excursions.