I. Introduction II. Study area III. Methods IV. Results V. Discussion - - PowerPoint PPT Presentation

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Jul 10, 2023 17 likes •213 views

Carbon and nitrogen mobilization along thermokarst-affected permafrost coasts and its degradation mechanisms before entering the near shore zone a George Tanski, Hugues Lantuit, Saskia Ruttor, Christian Knoblauch, Boris Radosavljevic, Jens

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Carbon and nitrogen mobilization along

thermokarst-affected permafrost coasts and its degradation mechanisms before entering the near shore zone

George Tanski, Hugues Lantuit, Saskia Ruttor, Christian Knoblauch, Boris Radosavljevic, Jens Strauss, Juliane Wolter, Anna Maria Irrgang, Justine Ramage, and Michael Fritz

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34% of global coasts 400,000km coastline 1/3 unlithified cliffs 18% ground ice 0.6m yr-1 erosion

Lantuit et al. 2012

I. Introduction II. Study area III. Methods IV. Results V. Discussion VI. Conclusion

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Tarnocai et al. 2009

*SOC content in 0–3 m of soils: 1035 ±150 Pg (Hugelius et al. 2014) 66 Pg nitrogen (N) in the uppermost 3 m (Harden et al. 2012)

Gt Corg. Global carbon storage in soils *

I. Introduction II. Study area III. Methods IV. Results V. Discussion VI. Conclusion

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Quantify and compare terrestrial OM contents
Assess transformation processes after affected by thermokarst
Track fate of terrestrial OM in the nearshore zone
I. Introduction II. Study area III. Methods IV. Results V. Discussion VI. Conclusion

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Ground ice 37% Coastal erosion 0.7m yr-1

Cont. permafrost

~600m depth

I. Introduction II. Study area III. Methods IV. Results V. Discussion VI. Conclusion

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I. Introduction II. Study area III. Methods IV. Results V. Discussion VI. Conclusion

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I. Introduction II. Study area III. Methods IV. Results V. Discussion VI. Conclusion

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I. Introduction II. Study area III. Methods IV. Results V. Discussion VI. Conclusion

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Undisturbed

(Active layer, Permafrost)

Disturbed

(Mudpool, Transition zone, Slump floor, Thaw stream)

Nearshore

(Marine sediments)

TOC TN δ13C-TOC DOC DN/DIN δ13C-DOC Bio- marker Ice volumes C/N δ13C NH4-N

I. Introduction II. Study area III. Methods IV. Results V. Discussion VI. Conclusion

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I. Introduction II. Study area III. Methods IV. Results V. Discussion VI. Conclusion

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Height 0.4m 2.5m 14.0m Vol. 3% 14% 83% DOC conc. 65.9 mg L-1 66.8 mg L-1 2.9 mg L-1

13.9 mg L-1 26.5 mg L-1

I II III

I. Introduction II. Study area III. Methods IV. Results V. Discussion VI. Conclusion

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I. Introduction II. Study area III. Methods IV. Results V. Discussion VI. Conclusion

C/N

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I. Introduction II. Study area III. Methods IV. Results V. Discussion VI. Conclusion

NH4-N

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I. Introduction II. Study area III. Methods IV. Results V. Discussion VI. Conclusion

Bio- marker

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I. Introduction II. Study area III. Methods IV. Results V. Discussion VI. Conclusion

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I. Introduction II. Study area III. Methods IV. Results V. Discussion VI. Conclusion

 OM contents decrese substantially due to thermokarst formation before entering the nearshore zone  Dilution, mineralzation, direct transport, and plant uptake as main transformation mechanisms  OM directly buried in nearshore sediments, esp. heavier fractions  OM characteristics are drastically changed due to theromkarst  Thermokarst along ice-rich coasts with strong impact on the coastal environment

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What happens with permafrost carbon after transport into the ocean? What are possible impacts on marine ecosystem in the nearshore? How is OC incorporated into local food webs?

I. Introduction II. Study area III. Methods IV. Results V. Discussion VI. Conclusion

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Acknowledgement

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Thank you very much for the attention!

www.awi.de/forschung/nachwuchsgruppen/coper Arctic coastal erosion group