See supplement

Review of Bryant et al., for The Cryosphere

This is a very well written paper that explores shoreline change for a region of the Alaskan Beaufort Sea Coast near Drew Point. They utilize ICESat2 data alongside high-resolution Planet imagery to quantify coastal change rates and morphology. Through this exploration, they examine the processes controlling coastal change and variability in process and form along the shoreline in three different regions.

I found this paper extremely easy to read and follow. I often found myself writing a comment to suggest some addition, only to find that it was addressed in the next paragraph I read. Thus, my review is quite short, as this paper is clear and worthy of prompt publication.

My only significant comment is that the authors would benefit from more clearly and directly explaining the novelty and scientific advance. I think that lies in two areas: first in the use of ICESat2 to explore coastal change and second in the authors’ ability to interpret mechanisms and processes of coastal change from remotely sensed data, which is often quite difficult if not impossible. These are both stated in the paper, but the language can be beefed up a bit in the intro, discussion, and conclusions to really emphasize this.

Other, more minor comments:

L91-92: I don’t think this rate is representative of the entire Beaufort Sea Coast of Alaska. Isn’t the average reported rate there on the order of -1 m/yr? This is according to the Gibbs and Richmond 2017 data. Erosion is locally very fast at Drew Point, but this region is not representative of the broader Alaskan Beaufort Sea coast (Piliouras et al., 2023).

What is the reasoning/justification for calculating shoreline change in the north-south orientation rather than perpendicular to the local shoreline? This should be included in the paper.

The authors state that they manually identified the boundaries for the lower and upper shorelines from ICESat2 data. Can you provide some information in the main text about the criteria used to delineate these?

To what extent could you use other geospatial data products to help interpret these results? This may be especially helpful if you are concerned that ShoreZone is out of date given the rates of erosion here. The Jorgenson 2014 maps of thermokarst, ice content, etc. may be especially helpful and can be directly overlain on the modern landscape/shoreline, or Lara et al., 2018 landform mapping. References below.

Several typos throughout (some examples):

L103 typo ‘strudy’ should be ‘study’

L156 typo ‘only occur when retreat when ocean temperatures’

L252: spatially averaged shoreline retreat rate? Missing ‘retreat rate’

The Gibbs & Richmond dataset citation is, I believe, incorrect. And the DOI link ‘cannot be found.’ The 2017 reference should be more appropriate: https://pubs.usgs.gov/publication/ofr20171107

The referencing is mostly quite thorough, but a few others that I would suggest and have referenced above in individual comments:

Baranskaya A, Novikova A, Shabanova N, Belova N, Maznev S, Ogorodov S and Jones B M 2021 The role of thermal denudation in erosion of ice-rich permafrost coasts in an enclosed bay (Gulf of Kruzenstern, Western Yamal, Russia) Front. Earth Sci. 8 566227

Erikson L H, Gibbs A E, Richmond B M, Storlazzi C D, Jones B M and Ohman K A 2020 Changing storm conditions in response to projected 21st century climate change and the potential impact on an arctic barrier island–lagoon system—a pilot study for Arey Island and Lagoon, eastern Arctic Alaska U.S. Geological Survey Open-File Report 2020–1142 p 68

Jorgenson T, Shur Y, Kanevskiy M and Grunblatt J 2014 Permafrost database development—Characterization and mapping for Northern Alaska

Lara M J, Nitze I, Grosse G and McGuire A D 2018 Tundra landform and vegetation productivity trend maps for the Arctic coastal plain of northern Alaska Sci. Data 5 180058

Piliouras A, Jones B, Clevenger T, Gibbs A and Rowland J C 2023 Variability in terrestrial characteristics and erosion rates on the Alaskan Beaufort Sea coast. Env. Res. Letters.

Wobus C, Anderson R, Overeem I, Matell N, Clow G and Urban F 2011 Thermal erosion of a permafrost coastline: improving process-based models using time-lapse photography Arct. Antarct. Alp. Res. 43 474–84