Changing Climate and Microseismic Noise in Alaska
Description:
Arctic Climate is changing much more rapidly compared to the rest of the world. Numerous studies suggest an increase in the number and strength of extratropical cyclones along with the poleward shift of storm track over the years. These changes in the pattern can be accompanied by severe weather conditions such as winter storms, the build-up of waves and storm surges, or extreme precipitation events. Sea ice extent, on the other hand, has been declining since 1979 continuously in each month of the year. Historical reconstructions and palaeoclimate evidence suggest that Arctic sea ice loss in summer months since 1979 is unprecedented in the past 1000 years. Arctic sea ice decline, coupled with changing extratropical storm patterns, are resulting in rampant coastal erosion and pose severe threats to the arctic communities and ecology.
Ocean storms have long been understood to be the primary driver of microseism noise. Sea ice, on the contrary, suppresses the wave action on oceans dampening microseism production. The objective of our study is to identify how these ocean processes are linked to microseismic noise across the Alaska Seismic Network and by doing so obtain the ability to track, monitor, and forecast the impacts of these arctic changes. We find that waves in the Gulf of Alaska tend to create higher amplitude microseisms than waves of equivalent height in the Bering Sea. We trained a machine learning algorithm to predict microseismic power from significant wave height and sea ice concentration data with substantial accuracy. Feature importance from the model suggests that sea ice build-up close to the coast is what plays the major role in dampening microseismic noise. We also provide baseline observations for tracking microseismic noise and quantify the spatial and seasonal variation of the microseismic noise in different bands. Finally, we provide insights into the increasing coastal erosion period over the years. These patterns suggest more rapid coastal erosion in the future.
Session: Monitoring Climate Change With Seismology [Poster]
Type: Poster
Date: 4/18/2023
Presentation Time: 08:00 AM (local time)
Presenting Author: Sebin John
Student Presenter: Yes
Invited Presentation:
Authors
Sebin John Presenting Author Corresponding Author sjohn19@alaska.edu University of Alaska Fairbanks |
Michael West mewest@alaska.edu University of Alaska Fairbanks |
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Changing Climate and Microseismic Noise in Alaska
Category
Monitoring Climate Change With Seismology