Kucera, Michal
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Kucera, Michal
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Kucera, Michal
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Item type:Publication, History of ice sheets surrounding Baffin Bay and its link with oceanic conditions since MIS3(2017-12-14); ; ; Baffin Bay provides the ideal setting for studying the past interaction between the marine realm and the cryosphere. It was an important, but often overlooked, conduit for meltwater into the Labrador Sea and North Atlantic: a key site for deep-water formation and thus climate modulation. Marine sediment archives capture evidence of both ice sheet behaviour and oceanic conditions. Using two sediment cores collected from central Baffin Bay, with good preservation of biogenic carbonate, allowed for the construction of a robust, radiocarbon-dated chronology, as well as multi-proxy paleoceanographic reconstructions. Results indicate several periods of ice-sheet instability (termed Baffin Bay Detrital Carbonate Events, BBDCs) that have no clear phase-relationship with abrupt climatic changes seen over the last ca. 50 kyr BP. During the last deglacial period, these events do not appear to have been directly triggered by changing oceanic conditions. Results highlight the need for understanding the region response of ice-sheets to abrupt climatic changes and complex phase-relationships between the ocean and the cryosphere.doctoral thesis532 183 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Global change stress on symbiont-bearing foraminifera(2015-03-18); ; ; Symbiont-bearing benthic foraminifera are important calcium carbonate producers and excellent model organisms for studying the global change effects. This study showed that when elevated temperatures and ocean acidification act in concert, the physiological negative effects on these organisms are stronger and even synergistic. We identified a strong photosynthetic thermal tolerance using Pulse Amplitude Modulated Fluorometry on the species Pararotalia from the Eastern Mediterranean, showing intact photosymbiosis up to 36°C. Chronic photoinhibition occurred at 42°C after one week, despite no obvious decreased survival in the species. We show that juvenile shell development in Pararotalia is highly temperature sensitive and inhibited at 20°C and 35°C. Our results point out that only some foraminiferal species seem to be well adapted to temperatures above current summer maxima. This indicates that living species have differential potential to face consequences of global warming.doctoral thesis556 136