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(DOC) available for degradation, are lim- re-deposition events will increase their E.A.G., Turetsky, M.R., 2016, Circumpolar
ited. If a significant volume of POC is bur- impact on the local and regional carbon distribution and carbon storage of thermokarst
ied in delta deposits, however, the potential stores. Further work is required to identify landscapes: Nature Communications, v. 7, p.
1–11, https://doi.org/10.1038/ncomms13043.
for GHG release is minimized. Counter- the precise role of catastrophic thermokarst Planet Team, 2017, Planet Application Program
intuitively, catastrophic drainage of ther- lake drainage in Arctic carbon fluxes. Interface: In Space for Life on Earth: San Fran-
mokarst lakes, and gully and lake margin cisco, California, https://api.planet.com/ (accessed
erosion, may provide limited carbon release ACKNOWLEDGMENTS 26 Feb. 2021).
to the atmosphere. We thank Georgina Heldreich for valuable dis- Schuur, E.A., Mcguire, A.D., Schädel, C., Grosse,
cussions on delta formation, and the two construc- G., Harden, J.W., Hayes, D.J., Hugelius, G.,
METHODS AND RESULTS tive anonymous reviews, which greatly improved Koven, C.D., Kuhry, P., Lawrence, D.M., Natali,
S.M., Olefeldt, D., Romanovsky, V.E., Schaefer,
the manuscript.
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1 Supplemental Material. Table S1: Geometric measurements obtained from satellite imagery of rapidly drained thermokarst lakes and associated deltas and thermo-erosion
gullies. Lake ID relates to drained lakes identified in Nitze et al. (2020). Table S2: Estimated soil organic carbon content measured in gigagram (Gg) in top 2 m removed
from thermo-erosion gullies. Estimates and approximate spatial resolution are derived from spatial statistical models presented in Zhu and McGuire (2016). Go to https://
doi.org/10.1130/GSAT.S.19083299 to access the supplemental material; contact editing@geosociety.org with any questions.

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