Landfast Ice and Coastal Wave Exposure in Northern Alaska

Abstract

Arctic coastlines experience rapid rates of erosion, up to tens of meters per year Jones et al., 2009). The mean retreat rate for coastlines throughout the Arctic is 0.5 m/yr (Lantuit et al., 2012), with the highest rates reported in the Laptev (Günther et al., 2013;Nielsen et al., 2020) and Beaufort Seas (Gibbs et al., 2015;Obu et al., 2017). The ice-rich soils are particularly sensitive to thermal niching by seawater at the coastal interface, a process which promotes failure of large blocks of ground along ice wedges (Aré, 1988a(Aré, , 1988bHequette & Barnes, 1990;Günther et al., 2015). Incident wave energy and storm surges are considered dominant factors influencing the erosion rate, as these carry seawater into contact with ice-rich soils and mobilize nearshore sediments (Wobus et al., 2011). In recent decades, summertime pack ice extents in the Arctic have been declining, and the length of the open-water season has been increasing (Barnhart et al., 2016;Meier et al., 2013), a trend that is projected to continue. These changes have been linked to an increase in wave climate (

Assessing Drivers of Coastal Tundra Retreat at Point Hope, Alaska

“…Given that there were observed differences in the RDD and ERA5 products relative to local site measurements and the unique geometry of the Point Hope site, the generated long‐term oceanographic record likely does not characterize the details of all extreme storms correctly along the northern shore of Point Hope (e.g., Sections 3.1.2 and 3.1.3). This includes potential biases from coarse resolution of the shoreline and potential inadequate definition of shorefast ice and their relative effects on waves in ERA5 (e.g., Hošeková et al., 2021). Thus, while the data indicates the relative rigor of these products, it is important to note that the timing and magnitude of predicted erosional impacts is dependent on these datasets for which the ultimate uncertainty on their use at Point Hope is unknown beyond the summer and fall 2021 data collection period.…”

Climate change hotspots and implications for the global subsea telecommunications network

“…sea ice that is fixed along the coast) often acts to protect the coast from such ice pile-up and wave inundation; however, the length of the landfast ice period has been decreasing since the 1980s, which may mean coastlines are increasingly exposed in future. This reduction has been linked with a recent increase in nearshore wave energy and the reduced protection of the coast (e.g., Hošeková et al, 2021;Walsh et al, 2022, see Section 3.6). Icebergs, including their smaller counterparts 'bergy bits', can plough (or gouge) the seabed.…”

Observations of Ocean Surface Wave Attenuation in Sea Ice Using Seafloor Cables

“…We also compare wave measurements from both methods with bulk wave parameters provided by the European Centre for Medium-Range Weather Forecasts Reanalysis v5 (ERA5) hindcast product (Hersbach et al, 2020). The waves from this reanalysis have already been shown to be inaccurate during seasonal transitions, when the hindcast lacks the necessary resolution (Hošeková et al, 2021). The native grid resolution of 31 km cannot be expected to capture on-shelf processes, though there is some representation of sub-grid bathymetry as "obstructions" that should be especially important for transformation of longer waves (Bidlot, 2012).…”