Climate change and seismic resilience: Key considerations for Alaska’s infrastructure and built environment

increase due to global climate warming, about 2.5 million square kilometers of permafrost in global arctic regions could be lost. In the discontinuous permafrost zone, where permafrost temperatures hover around the freezing point, the effects of rising temperatures are likely to be devastating. In these regions, even a small temperature increase may result in the total disap- pearance of permafrost [51]. Meanwhile, in the continuous permafrost zones, atmospheric temperature increase also raises the permafrost temperature, increasing the thickness of the active, seasonally thawed permafrost layer [52]. Estimates of the active layer thickness in Fig 3. Maps showing (a) The National Risk Index variation in Alaska determined based on earthquake hazard [25]. Republished from [25] under a CC BY license, with permission from the Federal Emergency Management Agency, original copyright 2021 and (b) Comparison of the 2008 Permafrost Characteristics of Alaska [45] and the United States Geological Survey (USGS) 2018 Long-Term National Seismic Hazard Map (public domain) [46] overlaid on the USGS National Map (public domain). The 2008 Permafrost Characteristics of Alaska map is republished from [45] under a CC BY license, with permission from the Institute of Northern Engineering, original copyright 2008. Permafrost distribution is classified as continuous (>90% of the land area underlain by permafrost), discontinuous (50–90% of the area), sporadic (10–50% of the area), or isolated (<10% of the area) [47]. https://doi.org/10.1371/journal.pone.0292320.g003 PLOS ONE

Climate change and seismic resilience: Key considerations for Alaska’s infrastructure and built environment PLOS ONE | https://doi.org/10.1371/journal.pone.0292320 October 18, 2023 6 / 17