Record of the Climatic Variability and the Sedimentary Dynamics during the Last Two Millennia at Sebkha Dkhila, Eastern Tunisia

This paper aimed to study the record of the climatic variability during the last two millennia within the sebkha of Dkhila. Six climatic stages were recognized along the 104 cm core: the Warming Present (WP), the Late Little Ice Age (Late LIA), the Early Little Ice Age (ELIA), the Medieval Climatic Anomaly (MCA), the Dark Age (DA), and the Roman Warm Period (RWP). The WP stretches along the uppermost 1 cm with a high grey scale as sign of a dry climate. The Late LIA is located between 1 cm and 6 cm. The ELIA is located between 6 cm and 40 cm. The MCA spanning from 40 cm to 72 cm is marked by a sharp increase of the GS revealing a wet period. The DA appears along the part between 72 cm and 84 cm; a shift from light to dark sediments is recorded. The RWP appears between 84 cm and 104 cm. Based on the grain size distribution, two low frequency cycles were identified indicating radical global changes of climatic conditions, the differential tectonics, and the groundwater fluctuations. On the other hand, high frequency cycles indicate local modifications of the climatic conditions.

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Variability to sedimentary dynamics and climatic conditions during the last two millennia at sebkha Souassi in eastern Tunisia

Papers on Global Change IGBP ◽

10.2478/igbp-2013-0001 ◽

2013 ◽

Vol 20 (1) ◽

Author(s):

Elhoucine Essefi ◽

Hayet Ben Jmaa ◽

Jamel Touir ◽

Mohamed Ali Tagortig ◽

Chokri Yaicha

Keyword(s):

Grain Size ◽

Size Distribution ◽

Grain Size Distribution ◽

Little Ice Age ◽

Climatic Variability ◽

Climatic Conditions ◽

Ice Age ◽

Global Changes ◽

Sedimentary Dynamics ◽

The Last Two Millennia

AbstractThis paper covers work intended to study the interplay of sedimentary dynamics and climatic variability over the last two millennia within Tunisia’s sebkha Souassi. Based on the Visual Core Description, and magnetic susceptibility, we date the core from sebkha Souassi to the last two millennia. Genetic grain-size distribution then provided a basis for the identification of six climatic stages, i.e. the Warming Present (WP), the Late Little Ice Age (Late LIA), the Early Little Ice Age (ELIA), the Medieval Climatic Anomaly (MCA), the Dark Ages (DA), and the Roman Warm Period (RWP). The WP stretches across the uppermost 3 cm, with a high grey scale indicating a dry climate. The Late LIA is located between 3 and 7 cm, and the ELIA between 7 and 28 cm. Intermediate values for GS indicate that this stage may be classified as moderate. The MCA spanning from 28 to 40 cm is marked by a sharp decrease in GS indicative of a wet period. The DA appear along the part between 40 and 79 cm, a shift from light to dark sediments being recorded. The RWP in turn appears between 79 and 114 cm. Based on the grain-size distribution, two low-frequency cycles were identified, indicating radical global changes in climatic conditions, differential tectonics and groundwater fluctuations. High-frequency cycles in turn attest to local modifications of climatic conditions.

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Sedimentary Dynamics Within the Sedimentary Filling of Sebkha Sidi El Hani, Eastern Tunisia

10.4018/978-1-7998-8459-0.ch012 ◽

2022 ◽

pp. 235-259

Author(s):

Elhoucine Essefi ◽

Soumaya Hajji ◽

Mohamed Ali Tagorti

Keyword(s):

Little Ice Age ◽

Climatic Variability ◽

Ice Age ◽

Genetic Approach ◽

Grey Scale ◽

Stable Conditions ◽

Salt Crust ◽

Sedimentary Dynamics ◽

Core Description ◽

The Last Two Millennia

The Sidi El Hani Wetland is located in Eastern Tunisia. It represents the natural outlet of an endorheic system, Mechertate-Chrita-Sidi El Hani, and it collects all the eroded sediment from this watershed. In this chapter, the visual core description focused on three reference sandy bands and on the concept of grey scale variability in order to infer the clay pan response to the climatic variability and erosion during the last two millennia. First, in the uppermost part, the stage Warming Present (WP) stretches from (1954-80= 1874) to 1993, i.e. ≈120yrs; the establishment of modern conditions is characterized by stable conditions with high grey scale. Added to a small salt crust, this period is dominated by a clayey sedimentation. Second, the stage C4 is called the Late Little Ice Age (Late LIA); it stretches between the 80yrBP and 400yrBP, i.e., 320yrs. It is characterized by intermediate GS values; the clayey sedimentation makes up the twofold and threefold laminates. Based on laser granulometer, the genetic approach shows the interplay of eolian and hydraulic erosion.

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Record of the Sedimentary Dynamics and Climatic Variability Within the Sedimentary Filling of Mchiguig Wetland During the Late Holocene

10.4018/978-1-7998-9498-8.ch015 ◽

2022 ◽

pp. 252-266

Author(s):

Elhoucine Essefi

Keyword(s):

Solar Activity ◽

Little Ice Age ◽

Climatic Variability ◽

Ice Age ◽

Medieval Climatic Anomaly ◽

Climatic Anomaly ◽

Sedimentary Dynamics ◽

Atmospheric Factors ◽

Sun Activity ◽

Great Acceleration

This work aimed to study the cyclicity of the geochemical chemical parameters and the carbonate percentages along a 59 cm core from the sebkha of Mchiguig, Central Tunisia. In fact, from the bottom upwards, six climatic phases were recorded including the Warming Present (Great Acceleration), the Late Little Ice Age (Anthropocene), the Early Little Ice Age, the Medieval Climatic Anomaly, the Dark Age, and the Roman Warm Period. In fact, the spectral analysis of the studied parameters visualized many cycles. Those cycles are related to sun activity, oceanographic, and atmospheric factors. Solar activity generated 500 yr cycles; however, the oceanographic circulation generated other cycles of 1500 yr and 700-800 yr. The 1500 yr cycle may be the result of the solar activity and NAO-like circulation.

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Marsh benthic Foraminifera response to estuarine hydrological balance driven by climate variability over the last 2000 yr (Minho estuary, NW Portugal)

Quaternary Research ◽

10.1016/j.yqres.2014.04.014 ◽

2014 ◽

Vol 82 (2) ◽

pp. 318-330 ◽

Cited By ~ 11

Author(s):

João Moreno ◽

Francisco Fatela ◽

Eduardo Leorri ◽

José M. De la Rosa ◽

Inês Pereira ◽

...

Keyword(s):

Little Ice Age ◽

Climatic Variability ◽

Ice Age ◽

High Marsh ◽

Ne Atlantic ◽

Hydrological Balance ◽

Medieval Climatic Anomaly ◽

Low Salinity ◽

Salt Marsh Species ◽

Minho Estuary

AbstractA high-resolution study of a marsh sedimentary sequence from the Minho estuary provides a new palaeoenvironmental reconstruction from NW Iberian based on geological proxies supported by historical and instrumental climatic records. A low-salinity tidal flat, dominated by Trochamminita salsa, Haplophragmoides spp. and Cribrostomoides spp., prevailed from AD 140–1360 (Roman Warm Period, Dark Ages, Medieval Climatic Anomaly). This sheltered environment was affected by high hydrodynamic episodes, marked by the increase in silt/clay ratio, decrease of organic matter, and poor and weakly preserved foraminiferal assemblages, suggesting enhanced river runoff. The establishment of low marsh began at AD 1380. This low-salinity environment, marked by colder and wet conditions, persisted from AD 1410–1770 (Little Ice Age), when foraminiferal density increased significantly. Haplophragmoides manilaensis and Trochamminita salsa mark the transition from low to high marsh at AD 1730. Since AD 1780 the abundances of salt marsh species (Jadammina macrescens, Trochammina inflata) increased, accompanied by a decrease in foraminiferal density, reflecting climate instability, when droughts alternate with severe floods. SW Europe marsh foraminifera respond to the hydrological balance, controlled by climatic variability modes (e.g., NAO) and solar activity, thus contributing to the understanding of NE Atlantic climate dynamics.

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Climatic variability and human impact during the last 2000 years in western Mesoamerica: evidence of late Classic (AD 600–900) and Little Ice Age drought events

Climate of the Past ◽

10.5194/cp-11-1239-2015 ◽

2015 ◽

Vol 11 (9) ◽

pp. 1239-1248 ◽

Cited By ~ 13

Author(s):

A. Rodríguez-Ramírez ◽

M. Caballero ◽

P. Roy ◽

B. Ortega ◽

G. Vázquez-Castro ◽

...

Keyword(s):

Human Impact ◽

Little Ice Age ◽

Climatic Variability ◽

Seasonal Migration ◽

Ice Age ◽

Cultural Tradition ◽

Late Classic ◽

High Pressure Cell ◽

Western Mexico ◽

The North

Abstract. We present results of analysis of biological (diatoms and ostracodes) and non-biological (Ti, Ca / Ti, total inorganic carbon, magnetic susceptibility) variables from an 8.8 m long, high-resolution (~ 20 yr sample−1) laminated sediment sequence from Lake Santa María del Oro (SMO), western Mexico. This lake lies at a sensitive location between the dry climates of northern Mexico, under the influence of the North Pacific subtropical high-pressure cell and the moister climates of central Mexico, under the influence of the seasonal migration of the intertropical convergence zone and the North American monsoon (NAM). The sequence covers the last 2000 years and provides evidence of two periods of human impact in the catchment, shown by increases in the diatom Achnanthidium minutissimum. The first from AD 100 to 400 (Early Classic) is related to the shaft and chamber tombs cultural tradition in western Mexico, and the second is related to Post-Classic occupation from AD 1100 to 1300. Both periods correspond to relatively wet conditions. Three dry intervals are identified from increased carbonate and the presence of ostracodes and aerophilous Eolimna minima. The first, from AD 500 to 1000 (most intense during the late Classic, from AD 600 to 800), correlates with the end of the shaft and chamber tradition in western Mexico after ca. AD 600. This late Classic dry period is the most important climatic signal in the Mesoamerican region during the last 2000 years, and has been recorded at several sites from Yucatan to the Pacific coast. In the Yucatan area, this dry interval has been related with the demise of the Maya culture at the end of the Classic (AD 850 to 950). The last two dry events (AD 1400 to 1550 and 1690 to 1770) correspond with the onset of, and the late, Little Ice Age, and follow largely the Spörer and Maunder minima in solar radiation. The first of these intervals (AD 1400 to 1550) shows the most intense signal over western Mexico; however this pattern is different at other sites. Dry/wet intervals in the SMO record are related with lower/higher intensity of the NAM over this region, respectively.

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Late Holocene environmental reconstructions and the implications on flood events, typhoon patterns, and agriculture activities in NE Taiwan

Climate of the Past Discussions ◽

10.5194/cpd-10-1977-2014 ◽

2014 ◽

Vol 10 (3) ◽

pp. 1977-2009 ◽

Cited By ~ 1

Author(s):

L.-C. Wang ◽

H. Behling ◽

T.-Q. Lee ◽

H.-C. Li ◽

C.-A. Huh ◽

...

Keyword(s):

Little Ice Age ◽

Phase 1 ◽

Warm Pool ◽

Climatic Conditions ◽

Environmental Stability ◽

Ice Age ◽

Flood Events ◽

Hydrological Conditions ◽

Enso Events ◽

The Pacific

Abstract. In this study, we reconstructed the paleoenvironmental changes from a sediment archive of the floodplain lake in Ilan Plain of NE Taiwan on multi-decadal resolution for the last ca. 1900 years. On the basis of pollen and diatom records, we evaluated the record of past vegetation, floods, typhoons and agriculture activities of this area, which is sensitive to the hydrological conditions of the West Pacific. High sedimentation rates with low microfossil preservations reflected multiple flood events and humid climatic conditions during 100–1400 AD. A shortly interrupted dry phase can be found during 940–1010 AD. The driest phase corresponds to the Little Ice Age phase 1 (LIA1, 1400–1620 AD) with less disturbance by flood events, which enhanced the occurrence of wetlands (Cyperaceae) and diatom depositions. Humid phases with frequent typhoons are inferred by high percentages of Lagerstroemia and high ratios of planktonic/benthic diatoms, respectively, during 500–700 AD and Little Ice Age phase 2 (LIA2, 1630–1850 AD). The occurrences of cultivated Poaceae (Oryza) during 1250–1300 AD and the last ~400 years, reflect agriculture activities, which seems to implicate strongly with the environmental stability. Finally, we found flood events which dominated during the El Niño-like stage, but dry events as well as frequent typhoon events happened during the La Niña-like stage. After comparing our results with the reconstructed proxy for tropical hydrological conditions, we suggested that the local hydrology in coastal East Asia were strongly affected by the typhoon-triggered heavy rainfalls which were influenced by the variation of global temperature, expansion of the Pacific warm pool and intensification of ENSO events.

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A importância da acção do frio do Quaternário final em Portugal e suas implicações nas morfodinâmicas de vertente.

Revista Brasileira de Geografia Física ◽

10.26848/rbgf.v5i2.232748 ◽

2012 ◽

Vol 5 (2) ◽

pp. 421

Author(s):

António Sousa Pedrosa

Keyword(s):

Little Ice Age ◽

Late Quaternary ◽

Climatic Conditions ◽

Ice Age ◽

Glacial Deposits ◽

Central Portugal

Resumo De entre os factores que tiveram maior influência na evolução do relevo de Portugal no decurso final do Quaternário é incontestável que o frio e os processos que lhe estão associados tiveram um papel muito importante na modelação das formas de relevo. Neste trabalho procuraremos fazer uma síntese dos principais aspectos da evolução das vertentes relacionados com os frio, inferir através dos vestígios que chegaram até ao nossos dias quais as condições morfo-climáticas em que ocorreram e quais os processos que lhes estavam encontravam associados. Realçamos assim o papel da acção dos glaciares nas áreas onde ocorreram assim como a importância dos processos periglaciares na evolução das vertentes. O período tardiglaciar também se mostrou marcante na dinâmica de vertentes tendo mobilizado e remobilizado muito material nas vertentes através de solifluxões generalizadas levando muitas delas à sua regularização. O período conhecido como a pequena idade do gelo também deixou as suas marcas na dinâmica das vertentes às quais se associam as escombreiras de gravidade. Por fim enfatizamos um pouco o papel do frio na actual morfodinâmica de vertentes no Norte de Centro de Portugal. Palavras-chave: Norte de Portugal; Montanhas, depósitos glaciares, depósitos periglaciares, dinâmica de vertentes Summary Among the factors that most influenced the evolution of the relief of Portugal during the late Quaternary is incontestable that the cold and the processes associated with it had a very important role in modeling the forms of relief. In this paper, we will try to summarize the importance that the cold had on the evolution of slopes, inferred through the vestiges that have come down to our day, which morpho-climatic conditions in which they occur, and also what processes if they were associated with. Thus enhancing the role of action in areas where glaciers have occurred and the importance of periglacial processes in the evolution of the slopes. In tardiglaciar the dynamics of slopes was very active and mobilized a lot of material through the process of solifluction regularized many of them. The period known as the Little Ice Age has also left its mark on the dynamic slopes which relate to tailings heaps of gravity. Finally we emphasize the role of cold in the current slopes of morphodynamics in north and central Portugal. Keywords: North of Portugal; mountains, glacial deposits, periglacial deposits, morphodynamics of slopes

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The Toledo Mountains: A Resilient Landscape and a Landscape for Resilience? Hazards and Strategies in a Mid-Elevation Mountain Region in Central Spain

Quaternary ◽

10.3390/quat2040035 ◽

2019 ◽

Vol 2 (4) ◽

pp. 35 ◽

Cited By ~ 1

Author(s):

Reyes Luelmo-Lautenschlaeger ◽

Sebastián Pérez-Díaz ◽

Olivier Blarquez ◽

César Morales-Molino ◽

José Antonio López-Sáez

Keyword(s):

Climatic Variability ◽

Central Area ◽

Climatic Conditions ◽

Mediterranean Vegetation ◽

Ice Age ◽

Mountain Range ◽

Taxus Baccata ◽

Central Spain ◽

Ilex Aquifolium ◽

Original Distribution

The Toledo Mountains are a mid-elevation mountain range that separates the Tagus and Guadiana basins in the central area of the Iberian Peninsula. The location of these mountains allows the development of typical Mediterranean vegetation with some Atlantic influence. Consequently, typical broadleaved evergreen Mediterranean vegetation currently dominates the regional landscape, with the remarkable presence of more mesophilous species in sheltered and more humid microsites such as gorges (e.g., Prunus lusitanica, Taxus baccata, Ilex aquifolium) and mires/bogs (e.g., Betula pendula susbp. fontqueri, Erica tetralix, Myrica gale). Palaeoecological studies in these mountains are essential to understand the long-term ecology and original distribution of these valuable communities and are key to assess their resilience. Understanding the hazards and opportunities faced in the past by the plant communities of the Toledo Mountains is necessary to enhance the management and protection of those species currently threatened. This study focuses on El Perro mire, a peatland on the southern Toledo Mountains (central Spain) where climatic variability has played a major role in landscape dynamics at multi-decadal to millennial timescales. Climatic events such as the 4.2 ka cal. Before Present (BP) or the Little Ice Age triggered relevant landscape changes such as the spread and latter decline of birch and hazel forests. Human communities also seemed to be affected by these events, as their resilience was apparently jeopardized by the new climatic conditions and they were forced to find new strategies to cope with the new scenarios.

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Recent Climatic Mass Balance of the Schiaparelli Glacier at the Monte Sarmiento Massif and Reconstruction of Little Ice Age Climate by Simulating Steady-State Glacier Conditions

Geosciences ◽

10.3390/geosciences10070272 ◽

2020 ◽

Vol 10 (7) ◽

pp. 272

Author(s):

Stephanie Suzanne Weidemann ◽

Jorge Arigony-Neto ◽

Ricardo Jaña ◽

Guilherme Netto ◽

Inti Gonzalez ◽

...

Keyword(s):

Steady State ◽

Mass Balance ◽

Air Temperature ◽

Little Ice Age ◽

Similar Rate ◽

Climatic Conditions ◽

Ice Age ◽

Balance Model ◽

Climate Conditions ◽

Recent Climate

The Cordillera Darwin Icefield loses mass at a similar rate as the Northern and Southern Patagonian Icefields, showing contrasting individual glacier responses, particularly between the north-facing and south-facing glaciers, which are subject to changing climate conditions. Detailed investigations of climatic mass balance processes on recent glacier behavior are not available for glaciers of the Cordillera Darwin Icefield and surrounding icefields. We therefore applied the coupled snow and ice energy and mass balance model in Python (COSIPY) to assess recent surface energy and mass balance variability for the Schiaparelli Glacier at the Monte Sarmiento Massif. We further used COSIPY to simulate steady-state glacier conditions during the Little Ice Age using information of moraine systems and glacier areal extent. The model is driven by downscaled 6-hourly atmospheric data and high resolution precipitation fields, obtained by using an analytical orographic precipitation model. Precipitation and air temperature offsets to present-day climate were considered to reconstruct climatic conditions during the Little Ice Age. A glacier-wide mean annual climatic mass balance of −1.8 ± 0.36 m w.e. a − 1 was simulated between between April 2000 and March 2017. An air temperature decrease between −0.9 ° C and −1.7 ° C in combination with a precipitation offset of up to +60% to recent climate conditions is necessary to simulate steady-state conditions for Schiaparelli Glacier in 1870.

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Impacts of climate and river flooding on the hydro-ecology of a floodplain basin, Peace-Athabasca Delta, Canada since A.D. 1700

Quaternary Research ◽

10.1016/j.yqres.2005.05.001 ◽

2005 ◽

Vol 64 (2) ◽

pp. 147-162 ◽

Cited By ~ 48

Author(s):

Brent B. Wolfe ◽

Tammy L. Karst-Riddoch ◽

Sheila R. Vardy ◽

Matthew D. Falcone ◽

Roland I. Hall ◽

...

Keyword(s):

Lake Sediment ◽

Climatic Variability ◽

Ecological Status ◽

Ring Width ◽

Climatic Conditions ◽

Ice Age ◽

Water Flooding ◽

Hydroelectric Power ◽

Peace River ◽

Isotopic Analyses

AbstractMulti-proxy paleolimnological analyses on lake sediment cores from "Spruce Island Lake" (58° 50.82′ N, 111° 28.84′ W), a perched basin in the northern Peace sector of the Peace-Athabasca Delta (PAD), Canada, give insights into the relative roles of flow regulation of the Peace River and climatic variability on the basin hydro-ecology. Results indicate substantial variability in basin hydro-ecology over the past 300 years ranging from seasonal to periodic desiccation in the 1700s to markedly wetter conditions during the early 1800s to early 1900s. The reconstruction is consistent with (1) dry climatic conditions that defined the peak of the Little Ice Age and subsequent amelioration evident in conventional ring-width and isotopic analyses of tree-ring records located hydrologically and climatically upstream of the PAD, and (2) Peace River flood history inferred from sub-annual magnetic susceptibility measurements from another lake sediment record in the Peace sector of the PAD. Although regulation of the Peace River for hydroelectric power generation since 1968 has long been considered a major stressor of the PAD ecosystem leading to reduced frequency of ice-jam and open-water flooding and an extended period of drying, our results show that current hydro-ecological status is not unprecedented as both wetter and drier conditions have persisted for decades in the recent past under natural climatic variability. Furthermore, paleolimnological evidence from Spruce Island Lake indicates that recently observed dryness is part of a longer trend which began some 20�"40 years prior to Peace River regulation.

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