Distressing Math Collective with Sophia Midgley

Abstract: The National Tsunami Warning Center (NTWC), located in Palmer, Alaska, maintains and operates sea level gauges in the Barry Arm fjord, Prince William Sound, to detect tsunamis from a potentially catastrophic landslide. While this low probability, high-impact event has yet to occur, numerous smaller events have created measurable wave disturbances, including from ship wakes and glacier calving events. Identifying these events and determining their characteristics can be used to verify numerical models that are used to model a large landslide-induced tsunami that could have a devastating impact on communities in Prince William Sound. Detecting seiche resonances is challenging because they are low-amplitude events contaminated by additive sensor noise and structured interference, such as wind-driven waves. Fortunately, their frequency content is repeatable, which allows them to be isolated from the background interference. We identify these events by decomposing the time series from a known calving event over the frequency band of interest to create a target function prototype. We then perform a hypothesis test to determine if a test signal is statistically the same as the target signal. Sea level data recorded from 2022 to 2024 are used to identify several events that can be used for more in-depth oceanographic analysis.