Title | Revised Magmatic Source Models for the 2015 Eruption at Axial Seamount Including Estimates of Fault‐Induced Deformation |
Publication Type | Journal Article |
Year of Publication | 2020 |
Authors | Hefner, WL, Nooner, SL, Chadwick, WW, Bohnenstiehl, DWR |
Journal | Journal of Geophysical Research: Solid Earth |
Volume | 125 |
Type of Article | Journal Article |
Abstract | Axial Seamount is an active submarine volcano located at the intersection of the Cobb hot spot and the Juan de Fuca Ridge (45°57′N, 130°01′W). Bottom pressure recorders captured co-eruption subsidence of 2.4–3.2 m in 1998, 2011, and 2015, and campaign-style pressure surveys every 1–2 years have provided a long-term time series of inter-eruption re-inflation. The 2015 eruption occurred shortly after the Ocean Observatories Initiative (OOI) Cabled Array came online providing real-time seismic and deformation observations for the first time. Nooner and Chadwick (2016, https://doi.org/10.1126/science.aah4666) used the available vertical deformation data to model the 2015 eruption deformation source as a steeply dipping prolate-spheroid, approximating a high-melt zone or conduit beneath the eastern caldera wall. More recently, Levy et al. (2018, https://doi.org/10.1130/G39978.1) used OOI seismic data to estimate dip-slip motion along a pair of outward-dipping caldera ring faults. This fault motion complicates the deformation field by contributing up to several centimeters of vertical seafloor motion. In this study, fault-induced surface deformation was calculated from the slip estimates of Levy et al. (2018, https://doi.org/10.1130/G39978.1) then removed from vertical deformation data prior to model inversions. Removing fault motion resulted in an improved model fit with a new best-fitting deformation source located 2.11 km S64°W of the source of Nooner and Chadwick (2016, https://doi.org/10.1126/science.aah4666) with similar geometry. This result shows that ring fault motion can have a significant impact on surface deformation, and future modeling efforts need to consider the contribution of fault motion when estimating the location and geometry of subsurface magma movement at Axial Seamount. |
DOI | 10.1029/2020jb019356 |
Array | Regional Cabled |
Bibliometrics |
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