scholarly journals Environmental conditions of interstadial (MIS 3) and features of the last glacial maximum on the King George island (West Antarctica)

2015 ◽  
Vol 121 (1) ◽  
pp. 111
Author(s):  
S. R. Verkulich ◽  
M. V. Dorozhkina ◽  
Z. V. Pushina ◽  
A. Tatur ◽  
D. I. Sukhomlinov ◽  
...  
Geology ◽  
2005 ◽  
Vol 33 (4) ◽  
pp. 281 ◽  
Author(s):  
E.D. Waddington ◽  
H. Conway ◽  
E.J. Steig ◽  
R.B. Alley ◽  
E.J. Brook ◽  
...  

2021 ◽  
Author(s):  
Fabrizio Antonioli ◽  
Lucio Calcagnile ◽  
Luigi Ferranti ◽  
Giuseppe Mastronuzzi ◽  
Carmelo Monaco ◽  
...  

<p>Estimates of global ice volume during MIS 3 (60-29 ka) can be constrained between -25 and -87 m (Shackleton, 2000; Waelbroeck et al., 2002; Clark et al., 2009; Hughes et al., 2013; Grant et al., 2014). As regards the maximum altitude reached during this period there are few observed data for a comparison between the global curves and the variations due to different rheostay of the mantle in coastal areas. Uncertainties on the rheostatic behaviour near- or far-fields from the ice bulk during cold period, make it very difficult to estimate the local sea level during MIS 3. Several factors make investigations of  MIS 3 sea level difficult: i) the areas where suitable coastal sediments formed are currently submerged at depths of few tens of meters below present sea level; ii) the preservation of geomorphic features and sedimentary records is limited due to the erosion occurred during the Last Glacial Maximum (LGM) with sea level at depth of -130m, followed by marine transgression that determined  the development of ravinement surfaces).</p><p>Few data were observed worldwide, especially when tectonics or GIA in the near field leads to uplifts. Our research aims to point out what has been published globally and in the Mediterranean, but, above all, to illustrate the sections of new outcrops in Cannitello (Calabria, Italy) where we have found and dated fossiliferous marine pocket beaches deposited on uplifted bed metamorphic rock. Radiocarbon ages of marine shells (about 43 kyrs cal BP) indicate that these outcrops (presently at 28 and 30 meters above sea level) belong to MIS 3.1. Based on some considerations regarding the altitude of MIS 3.1 highstand, the correction for altitude with the local vertical tectonic movements and GIA of the Cannitello outcrops allows us to revise the eustatic altitude of this highstand. This is consistent with the recent findings (Gowan et al., 2020), which are based on a novel ice sheet modelling technique.</p><p>Clark, P.U., Dyke, A.S., Shakun, J.D., Carlson, A.E., Clark, J., Wohlfarth, B., Mitrovica, J.X., Hostetler, S.W., McCabe, A.M., 2009. The Last Glacial Maximum. Science 325, 710–714. doi:10.1126/science.1172873</p><p>Gowan, E.J., Zhang, X., Khosravi, S., Rovere, A., Stocchi, P., Hughes, A. C., Gyllencreutz, R., Mangerud, J., Svendsen, J. I., Lohmann, G. (in print): Global ice sheet reconstruction for the past 80000 years. PANGEA, Earth & Environmental Science https://doi.org/10.1594/PANGAEA.905800.</p><p>Grant, K.M., Rohling, E.J., Ramsey, C.B., Cheng, H., Edwards, R.L., Florindo, F., Heslop, D., Marra, F., Roberts, A.P., Tamisiea, M.E., Williams, F., 2014. Sea-level variability over five glacial cycles. Nature Communications 5, 5076. doi:10.1038/ncomms6076</p><p>Hughes, P.D., Gibbard, P.L., Ehlers, J., 2013. Timing of glaciation during the last glacial cycle: evaluating the concept of a global ‘Last Glacial Maximum’ (LGM). Earth-Science Reviews 125, 171–198. doi:10.1016/j.earscirev.2013.07.003</p><p>Shackleton, N.J., 2000. The 100,000-Year Ice-Age Cycle Identified and Found to Lag Temperature, Carbon Dioxide, and Orbital Eccentricity. Science 289, 1897–1902. doi:10.1126/science.289.5486.1897</p><p>Waelbroeck, C., Labeyrie, L., Michel, E., Duplessy, J.C., McManus, J.F., Lambeck, K., Balbon, E., Labracherie, M., 2002. Sea-level and deep water temperature changes derived from benthic foraminifera isotopic records. Quaternary Science Reviews, EPILOG 21, 295–305. doi:10.1016/S0277-3791(01)00101-9</p>


2021 ◽  
pp. 10-17
Author(s):  
Oguz Turkozan

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.


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