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

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.

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

ISRN Geology ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Elhoucine Essefi ◽  
Jamel Touir ◽  
Mohamed Ali Tagorti ◽  
Chokri Yaich
Keyword(s):  
Little Ice Age ◽  
Climatic Variability ◽  
Low Frequency ◽  
Climatic Conditions ◽  
Ice Age ◽  
Global Changes ◽  
Medieval Climatic Anomaly ◽  
Grey Scale ◽  
Sedimentary Dynamics ◽  
The Last Two Millennia

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.

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

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.

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

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.

scholarly journals 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

2015 ◽  
Vol 11 (9) ◽  
pp. 1239-1248 ◽  
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.

scholarly journals Climatic variability and human impact during the last 2000 years in western Mesoamerica: evidences of late Classic and Little Ice Age drought events

2015 ◽  
Vol 11 (3) ◽  
pp. 1887-1911
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 ◽  
North American Monsoon ◽  
Cultural Tradition ◽  
Late Classic ◽  
Western Mexico ◽  
The North

Abstract. Results are presented from biological (diatoms and ostracodes) and non-biological (Ti, Ca/Ti, total inorganic carbon, magnetic susceptibility) proxy analyses from an 8.8 m long laminated, high resolution (~20 yr sample−1) sediment sequence from lake Santa María del Oro (SMO), in western Mexico. This lake is at a sensitive location between the dry climates of northern Mexico, under the influence of the north Pacific High Pressure Subtropical 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 that last 2000 years and gives evidence of two periods of human impact in the lake, shown by increases in Achnanthidium minutissimum, the first related with the Shaft and Chamber Tombs Cultural Tradition from 100 BC to AD 300 and a second late Postclassic occupation from AD 1100 to 1300. Both periods correspond to relatively wet conditions. The sequence also gives evidence of three dry intervals with high carbonates, ostracodes and aerophilous Eolimna minima concentrations. The first, from AD 500 to 1000 (most intense from AD 600 to 800), correlates with the end of the Shaft and Chamber Tradition after ca. AD 600. This late Classic dry period is the most important climatic signal for the Mesoamerican region during the last 2000 years, as it 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 between AD 850 and 950. The last two dry events correspond with the onset and late Little Ice Age (1400 to 1550 and 1690 to 1770), and follow the Spörer and Maunder minima in solar radiation. The first of these intervals (1400–1550) shows the most intense signal over western Mexico, however this pattern changes at other sites. Dry/wet intervals in the SMO record are related with lower/higher intensity of the NAM over this region.

scholarly journals De sequías a riadas: casos de alta variabilidad climática desde las fuentes eclesiásticas de Orihuela (1700-1750)

2019 ◽  
pp. 37-67
Author(s):  
Claudio Cremades Prieto
Keyword(s):  
Little Ice Age ◽  
18Th Century ◽  
Climatic Variability ◽  
Ice Age ◽  
Historical Evolution ◽  
Religious Institution ◽  
Droughts And Floods ◽  
The Relationship ◽  
Industrial Societies ◽  
Over Time

RESUMENEste estudio analiza los impactos de sequías e inundaciones en el Bajo Segura durante la primera mitad del siglo xviii. Apoyándonos en trabajos precedentes, hemos tratado de aportar datos inéditos sobre las repercusiones de los riesgos naturales. Para ello hemos analizado los Libros de Actas Capitulares del cabildo eclesiástico oriolano, custodiados en el Archivo Diocesano de Orihuela. El resultado es un recorrido cronológico por los contrastes climáticos del marco geográfico, acentuando los episodios hidrometeorológicos más extremos y delimitando en el tiempo los períodos de mayor irregularidad. Igualmente nos aproximamos a la relación entre el clima y el devenir histórico de las vulnerables sociedades preindustriales desde la perspectiva de la referida institución religiosa. Para dotar de mayor dimensión al estudio, nos acercaremos sucintamente a las fundamentales rogativas pro pluvia y pro serenitate, y cómo estas evolucionaron entre 1700 y 1750.PALABRAS CLAVEOrihuela, Pequeña Edad del Hielo, sequías, inundaciones, riadas, rogativas. TITLEFrom droughts to fl oods: high climatic variability cases from the ecclesiastical sources of Orihuela (1700-1750)ABSTRACTThis study analyzes the droughts and floods impacts in Bajo Segura during the first half of the 18th century. Supporting us in the precedents works, we tried to provide unpublished data on the repercussions of natural risks. For this purpose, we have turned over and analyzed the Chapter Record Books of the Oriolan Ecclesiastical Chapter, kept in the Diocesan Archives of Orihuela (A.D.O). The result is a chronological journey through the climatic contrasts of the geographical frame, accentuating the most extreme hydrometeorological episodes and delimiting periods of greatest irregularity over time. We also approach the relationship between the climate and the historical evolution of the vulnerable pre-industrial societies from the aforementioned religious institution perspective. To give a greater dimension to the study, we will briefly approach the fundamental rogation pro pluvia and pro serenitate, and how they evolved between 1700 and 1750.KEY WORDSOrihuela, Little Ice Age, droughts, floods, stream, rogation.

scholarly journals New Little ICE Age Instead of Global Warming?

2003 ◽  
Vol 14 (2-3) ◽  
pp. 327-350 ◽  
Author(s):  
Theodor Landscheidt
Keyword(s):  
Global Warming ◽  
Solar Activity ◽  
Little Ice Age ◽  
Orbital Motion ◽  
Maunder Minimum ◽  
Ice Age ◽  
Centre Of Mass ◽  
Long Period ◽  
The Last Two Millennia ◽  
Cool Climate

Analysis of the sun's varying activity in the last two millennia indicates that contrary to the IPCC's speculation about man-made global warming as high as 5.8°C within the next hundred years, a long period of cool climate with its coldest phase around 2030 is to be expected. It is shown that minima in the secular Gleissberg cycle of solar activity, coinciding with periods of cool climate on Earth, are consistently linked to an 83-year cycle in the change of the rotary force driving the sun's oscillatory motion about the centre of mass of the solar system. As the future course of this cycle and its amplitudes can be computed, it can be seen that the Gleissberg minimum around 2030 and another one around 2200 will be of the Maunder minimum type accompanied by severe cooling on Earth. This forecast should prove ‘skilful’ as other long-range forecasts of climate phenomena, based on cycles in the sun's orbital motion, have turned out correct, as for instance the prediction of the last three El Niños years before the respective event.

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

2014 ◽  
Vol 82 (2) ◽  
pp. 318-330 ◽  
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.

Indian Monsoon Rainfall Variability and associated Climatic forcings in the last two millennia inferred by a Stalagmite from the peninsular India

2020 ◽  
Author(s):  
Naveen Gandhi ◽  
Phannindra Reddy A. ◽  
Raghavan Krishnan ◽  
Madhusudan G. Yadava
Keyword(s):  
Little Ice Age ◽  
Monsoon Rainfall ◽  
Southern Oscillation ◽  
Indian Subcontinent ◽  
Rainfall Variability ◽  
Warm Period ◽  
Ice Age ◽  
Peninsular India ◽  
Rainfall Variations ◽  
The Last Two Millennia

<p>We present high temporal (near-annually) resolved δ<sup>18</sup>O values from absolutely dated stalagmite record that represents the Indian Summer Monsoon (ISM) rainfall variations for the Indian subcontinent spanning from 207 AD to 2014 AD. This rainfall reconstruction shows ISM varaitions for four major global climatic periods viz., Roman Warm Period (RWP), Dark Ages Cold Period (DACP), Medieval Warm Period (MWP) and Little Ice Age (LIA). Cave records from different patrs of the sub-continent synchronously show enhanced precipitation during DACP. This wet period was forced by Solar-induced El-NiNo Southern Oscillation (ENSO) and Tibetan Plateau Temperature. Cliamtic conditions were wetter during LIA than that during MWP, as the former witnessed more number of wet monsoon years. However, MWP witnessed the strongest and the weakest monsoon years in the last two millennia. The direct influence of Soalr activity on the position of Inter Tropical Convergance zone (ITCZ) might have caused the observed ISM variability of MWP. Altough ISM shows largest variability during MWP, the overall monsoon state was moving towards wetter conditions, forced by ENSO. Solar induced forcings on ENSO influenced ISM during LIA. Our results suggest of non-stationary dynamical forcings over ISM during different periods in the last two millennia.</p>

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