Glacial climate variations in southwestern Iran, 50 to 10 ka

2021 ◽  
Author(s):  
Mojgan Soleimani ◽  
Stacy Carolin ◽  
Alireza Nadimi ◽  
Gideon Henderson ◽  
Christoph Spötl
Keyword(s):  
Middle East ◽  
Environmental Changes ◽  
Eastern Mediterranean ◽  
Global Climate ◽  
Glacial Period ◽  
Zagros Mountains ◽  
Last Glacial ◽  
Southwestern Iran ◽  
The Persian Gulf ◽  
The Last Glacial

<p>Records of paleoclimate in the Middle East are particularly sparse in comparison with other regions around the world. In order to better resolve how Middle East climate responded to large global climate and environmental changes in the past, here we present the first glacial record of southwestern Iran climate constructed using speleothem climate proxies. We analyzed two stalagmites collected from a cave on the western side of the Zagros mountains, ~100 km north of the Persian Gulf. The average annual precipitation and temperature close to the cave site are ~350 mm and ~21.6 °C, respectively. Our data yield continuous δ<sup>18</sup>O and δ<sup>13</sup>C records from 45-35 kyr and 25-10 kyr BP, which show prominent millennial-scale events during the last glacial period and Termination I. The timing of these events is in agreement with North Atlantic Heinrich events and Greenland Daansgard-Oeschger events, within the respective records’ age errors. Moreover, unlike the generally stable NGRIP δ<sup>18</sup>O record, a proxy for high-latitude Northern Hemisphere temperatures, the stalagmite δ<sup>18</sup>O and δ<sup>13</sup>C records reveal clearly evident periodic variations during the Last Glacial Maximum. δ<sup>18</sup>O values are consistently heavier than eastern Mediterranean stalagmite δ<sup>18</sup>O values during both the glacial period and throughout Termination I, suggesting at least one source of moisture to the southwestern Iran site in addition to the westerlies.</p>

scholarly journals Cliff-front aeolian and colluvial deposits, Mallorca, Western Mediterranean: a record of climatic and environmental change during the last glacial period

2001 ◽  
Vol 48 ◽  
pp. 217-232
Author(s):  
Lars B. Clemmensen ◽  
Thomas Lisborg ◽  
Richard G. Bromley ◽  
Joan J. Fornós
Keyword(s):  
Environmental Change ◽  
Environmental Changes ◽  
Western Mediterranean ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Last Glacial ◽  
Aeolian Deposits ◽  
Climatic And Environmental Change ◽  
Sea Cliff ◽  
The Last Glacial

Large, cliff-front accumulations of Late Pleistocene aeolian and colluvial deposits on southeast Mallorca provide a terrestrial record of climatic and environmental change in the Western Mediterranean during the last glacial period. The cliff-front deposits are lithified and form ramps sloping toward the southeast (i.e. seaward). Radiocarbon dating suggests that the deposits formed in Oxygen Isope Stage 3, when sea level was about 50 m lower than today, and the fossil sea-cliff situated 1.5 to 2 km from the palaeo-shore. The aeolian deposits are composed of marine carbonate sand that was transported inland episodically and accumulated in embayments along the fossil sea-cliff. The sand initially formed steadily growing and forward-moving dunes, then sloping sand ramps and finally relatively small ascending dunes. Aeolian accumulation was interrupted by erosion and colluvial ramp formation, and the cliff-front sediments can be divided into two sedimentary cycles each composed of basal colluvial deposits overlain by aeolian deposits. Colluvial deposition probably records relatively humid climatic intervals, whereas aeolian accumulation probably reflects relatively arid climatic intervals. It appears that climatic and environmental changes were rapid, and it is speculated that the dynamics of the cliff-front system on Mallorca were tied to North Atlantic millennial-scale climate oscillations.

Rapid environmental changes in southern Europe during the last glacial period

Nature ◽  
10.1038/23432 ◽  
1999 ◽  
Vol 400 (6746) ◽  
pp. 740-743 ◽  
Author(s):  
Judy R. M. Allen ◽  
Ute Brandt ◽  
Achim Brauer ◽  
Hans-Wolfgang Hubberten ◽  
Brian Huntley ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Southern Europe ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Last Glacial ◽  
The Last Glacial

Improving age models for abrupt climate changes during the last glacial by pattern recognition

2020 ◽  
Author(s):  
Mark Turner ◽  
Sandy Harrison
Keyword(s):  
Pattern Recognition ◽  
Goodness Of Fit ◽  
Climate Changes ◽  
Global Climate ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Last Glacial ◽  
Global Climate Changes ◽  
Pollen Records ◽  
The Last Glacial

<p>Quaternary records provide an opportunity to examine how regional climates and vegetation reflect global climate changes comparable in magnitude and velocity to those expected during the 21st century.  The Dansgaard-Oeschger (D-O) cycles of the last glacial period provide the best documented examples of such rapid climate warmings (Greenland interstadials, GIs). However, the age models of pollen records that document regional responses to D-O events are, in general, poorly constrained beyond the radiocarbon timescale. Here we use a pattern-recognition approach, based on matching oscillations in palaeoclimate records to a template of D-O events seen in the Greenland record, to provide better constrained age models. We create a series of templates of Greenland Interstadials (GIs) and compare these to a normalised and detrended time series from a target record using a sliding window and measuring goodness-of-fit using Euclidian distance. We show that this approach can identify D-O events in well-dated records, including reproducing the Greenland record itself. We then apply this approach to the less well-constrained pollen records from the last glacial period from southern Europe. The re-aligned age models permit a more robust comparison of the reconstructed vegetation and climate changes through time and across sites, allowing for regional differences in the response to individual GIs to be identified.</p>

Paleoclimatic and archeological implications of Pleistocene and Holocene environments in Azraq, Jordan

2011 ◽  
Vol 76 (3) ◽  
pp. 363-372 ◽  
Author(s):  
Matthew D. Jones ◽  
Tobias Richter
Keyword(s):  
Environmental Changes ◽  
Eastern Mediterranean ◽  
Human Occupation ◽  
Last Glacial ◽  
The North ◽  
Time Period ◽  
Dry Conditions ◽  
Archeological Evidence ◽  
Climatic Transition ◽  
The Last Glacial

AbstractWetlands are a key archive for paleoclimatic and archeological work, particularly in arid regions, as they provide a focus for human occupation and preserve environmental information. The sedimentary record from 'Ayn Qasiyya, a spring site on the edge of the Azraq Qa, provides a well-dated sequence through the last glacial–interglacial transition (LGIT) allowing environmental changes in the present-day Jordanian desert to be investigated robustly through this time period for the first time. Results show that the wettest period at the site preceded the last glacial maximum, which itself was characterised by marsh formation and a significant Early Epipaleolithic occupation. A sedimentary hiatus between 16 and 10.5 ka suggests a period of drought in the region although seasonal rains and surface waters still allowed seasonal occupation of the Azraq region. Archeological evidence suggests that conditions had improved by the Late Epipaleolithic, about the time of the North Atlantic Younger Dryas. The changes between wet and dry conditions at the site show similarities to patterns in the eastern Mediterranean and in Arabia suggesting the Jordan interior was influenced by changes in both these regions through the LGIT climatic transition.

The diatom flora of Lake Lisan (Israel): a preliminary investigation

2020 ◽  
Author(s):  
Hannah Hartung ◽  
Jane M. Reed ◽  
Thomas Litt
Keyword(s):  
Lake Level ◽  
Eastern Mediterranean ◽  
Sediment Cores ◽  
Dead Sea ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Diatom Flora ◽  
Last Glacial ◽  
The Dead ◽  
The Last Glacial

<p>The Eastern Mediterranean, and the southern Levant in particular, is a key region for palaeoclimatological and palaeoenvironmental research due to its highly complex topography and climatic variability. Our understanding of environmental variability and its possible drivers, and the interaction with migration processes of modern <em>Homo sapiens</em> from a source area in Africa to Europe, is still limited. This is partly because continuous sediment records of sufficient age are rare across the Mediterranean Basin. The deposits of the Dead Sea represent an ideal archive to investigate palaeoenvironmental conditions during human migration phases in the Last Glacial period (MIS 4-2). </p><p>Diatoms (single-celled siliceous algae, Bacillariophyceae) have well-recognised potential to generate high-quality palaeolimnological data, especially in closed-basin saline lakes, but they remain one of the least-exploited proxies in Eastern Mediterranean palaeoclimate research. Here, we present preliminary results of a low-resolution diatom study derived from analysis of sediment deposits of Lake Lisan, the last glacial precursor of the Dead Sea. Sediment cores were recovered during an ICDP campaign in 2010/2011 from the centre of the modern Dead Sea. 18 sediment samples were analysed to investigate (a) the preservation of diatom valves in various evaporitic deposits (b) possible shifts in diatom species composition of Lake Lisan during the Last Glacial period, and (c) if diatoms can be used as proxy indicator for lake-level and, thus, palaeoclimate reconstruction. We focus on a prominent lake-level high stand of Lake Lisan at around 28-22 ka BP, which resulted in the merging Lake Lisan and freshwater Lake Kinneret.</p><p>First results show that the diatom preservation is exceptionally good in evaporitic deposits of the sediment cores from Lake Lisan, which is contradictory to the available literature. In contrast to Holocene deposits from the Dead Sea, diatoms are abundant in all analysed samples from laminated deposits from Lake Lisan: the diatom flora is dominated by halophilous benthic diatoms, such as <em>Amphora</em> spp., <em>Halamphora</em> spp. and <em>Nitzschia</em> spp. In phases of lake-level high stands of Lake Lisan, the diatom flora shifts towards a more plankton-dominated freshwater flora containing <em>Aulacoseira</em> spp. and taxa from the <em>Cyclotella-ocellata-</em>species complex.</p>

Bouldery slope landforms on Mt. Biseul, Korea, and implications for paleoclimate and slope evolution

2017 ◽  
Vol 88 (2) ◽  
pp. 293-312 ◽  
Author(s):  
Hyun-Hee Rhee ◽  
Yeong-Bae Seong ◽  
Young-Gweon Jeon ◽  
Byung-Yong Yu
Keyword(s):  
Chemical Weathering ◽  
Global Climate ◽  
Terrain Analysis ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Oxygen Isotope Stage ◽  
Last Glacial ◽  
Exposure Dating ◽  
Exposure Ages ◽  
The Last Glacial

AbstractIdentification of bouldery landforms in mountains and correctly understanding their formative processes play an important role in reconstructing the geomorphic history of a region. We propose that blocks were liberated by frost cracking and wedging of cliff walls during the last glacial period. However, we further suggest and test four hypotheses comprising different scenarios for preconditioning by chemical weathering and subsequent block transport using terrain analysis, characterization of boulders, and 10Be exposure dating. Frost shattering from the backing cliff produced the boulders since the beginning of the last glacial period (~80 ka), and gelifluction transported them downslope throughout the last glacial period. Their activity then entered a dormant phase at the beginning of the Holocene. Distribution patterns of exposure ages of tors and block streams are similar to those of previous studies, implying that bouldery landscapes in the southern Korean Peninsula were likely to be formed by similar processes under periglacial conditions. The timing of active periods in transport of block streams corresponds well with the cold periods identified in regional and global climate proxy records. Interestingly, the activity of block streams in the study area reached a maximum during Marine Oxygen Isotope Stage 3 to 2 when the growth rate of nearby speleothems was lowest.

Reconstructions of the past distribution of Testudo graeca mitochondrial lineages in the Middle East and Transcaucasia support multiple refugia since the Last Glacial Maximum

2021 ◽  
pp. 10-17
Author(s):  
Oguz Turkozan
Keyword(s):  
Middle East ◽  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Testudo Graeca ◽  
Last Glacial ◽  
The Past ◽  
Precipitation Seasonality ◽  
Multiple Refugia ◽  
The Last Glacial Maximum ◽  
The Last Glacial

A cycle of glacial and interglacial periods in the Quaternary caused species’ ranges to expand and contract in response to climatic and environmental changes. During interglacial periods, many species expanded their distribution ranges from refugia into higher elevations and latitudes. In the present work, we projected the responses of the five lineages of Testudo graeca in the Middle East and Transcaucasia as the climate shifted from the Last Glacial Maximum (LGM, Mid – Holocene), to the present. Under the past LGM and Mid-Holocene bioclimatic conditions, models predicted relatively more suitable habitats for some of the lineages. The most significant bioclimatic variables in predicting the present and past potential distribution of clades are the precipitation of the warmest quarter for T. g. armeniaca (95.8 %), precipitation seasonality for T. g. buxtoni (85.0 %), minimum temperature of the coldest month for T. g. ibera (75.4 %), precipitation of the coldest quarter for T. g. terrestris (34.1 %), and the mean temperature of the driest quarter for T. g. zarudyni (88.8 %). Since the LGM, we hypothesise that the ranges of lineages have either expanded (T. g. ibera), contracted (T. g. zarudnyi) or remained stable (T. g. terrestris), and for other two taxa (T. g. armeniaca and T. g. buxtoni) the pattern remains unclear. Our analysis predicts multiple refugia for Testudo during the LGM and supports previous hypotheses about high lineage richness in Anatolia resulting from secondary contact.

scholarly journals Post-depositional manganese mobilization during the last glacial period in sediments of the eastern Clarion-Clipperton Zone, Pacific Ocean

2020 ◽  
Vol 532 ◽  
pp. 116012 ◽  
Author(s):  
Jessica B. Volz ◽  
Bo Liu ◽  
Male Köster ◽  
Susann Henkel ◽  
Andrea Koschinsky ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Last Glacial ◽  
The Last Glacial
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