The evolution of tides and tidal dissipation over the past 21,000 years

The 120 m sea-level drop during the Last Glacial Maximum (LGM; 18–22 kyr BP) had a profound impact on the global tides and lead to an increased tidal dissipation rate, especially in the North Atlantic. Here, we present new simulations of the evolution of the global tides from the LGM to present for...

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Bibliographic Details
Published in:Journal of Geophysical Research: Oceans
Main Authors: Wilmes, S.B., Green, J.A.M.
Format: Article in Journal/Newspaper
Language:English
Published: 2014
Subjects:
Online Access:https://research.bangor.ac.uk/portal/en/researchoutputs/the-evolution-of-tides-and-tidal-dissipation-over-the-past-21000-years(59568041-954c-43d1-bfb7-2a7d17b04444).html
https://doi.org/10.1002/2013JC009605
https://research.bangor.ac.uk/ws/files/7307781/PDB236-00.pdf
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Summary:The 120 m sea-level drop during the Last Glacial Maximum (LGM; 18–22 kyr BP) had a profound impact on the global tides and lead to an increased tidal dissipation rate, especially in the North Atlantic. Here, we present new simulations of the evolution of the global tides from the LGM to present for the dominating diurnal and semidiurnal constituents. The simulations are undertaken in time slices spanning 500–1000 years. Due to uncertainties in the location of the grounding line of the Antarctic ice sheets during the last glacial, simulations are carried out for two different grounding line scenarios. Our results replicate previously reported enhancements in dissipation and amplitudes of the semidiurnal tide during LGM and subsequent deglaciation, and they provide a detailed picture of the large global changes in M2 tidal dynamics occurring over the deglaciation period. We show that Antarctic ice dynamics and the associated grounding line location have a large influence on global semidiurnal tides, whereas the diurnal tides mainly experience regional changes and are not impacted by grounding line shifts in Antarctica.