Is the tidal triggering of earthquakes at Axial Seamount predictive of eruptions?

TitleIs the tidal triggering of earthquakes at Axial Seamount predictive of eruptions?
Publication TypeThesis
Year of Publication2022
AuthorsCarlson, A
Academic DepartmentSchool of Oceanography
UniversityUniversity of Washington
CitySeattle, WA, USA
Thesis TypeSenior Thesis

Scientists have long hypothesized that tidal forces can trigger earthquakes due to the change in stress along a fault. This phenomenon is called tidal triggering of earthquakes. My study investigated the tidal triggering of earthquakes at Axial Seamount, Juan de Fuca Ridge from the time of the last eruption in 2015, to the present. This study tests the validity of the correlation between tidal triggering and volcanic cycles. My hypothesis is that the fraction of earthquakes is highest at low tidal heights / phases, and that tidal triggering increases in strength over time, therefore a potential sign during the onset of an eruption. Using data from the Ocean Observatories Initiative Regional Cabled Array, and the Oregon State University Tidal Model, I interpolated the time of earthquakes with the tidal cycle. Data from an earthquake catalog was plotted against the tidal model. Results prove my hypothesis to be valid. On an annual basis, the highest percentage of earthquakes occur within 30° of lowest tide (180°), and the highest rate of earthquakes per hour occur between -2m to -1m tidal height. On average, the percentage of earthquakes between 150° to 210° increases annually with a slope 1.88 %/y. Additionally, the relative rate of earthquakes at -2m to -1m increases by 0.24 per year. I propose that the Axial Seamount will erupt soon, given tidal triggering has increased in strength and current data reflects similar data to what was seen prior to the 2015 eruption.