Continuous and Drift Free Vertical Deformation Measurements at Axial Seamount - Installation of a Self Calibrating Pressure Recorder on the OOI Cabled Array

University Of California-San Diego Scripps Inst Of Oceanography, La Jolla CA

Investigators

Abstract

Seafloor volcanoes are important dynamic features of our environment both in how they shape the surface of the earth and how they support life at the seafloor. Seafloor volcanoes are not easily accessible, however. The Cabled Array component of the Ocean Observatories Initiative provides the infrastructure and instruments to observe an active volcano offshore Oregon, Axial Volcano. Axial Volcano has erupted in 1998, 2011, and 2015. This project will add a new, continuously operating instrument, the Self-Calibrating Pressure Recorder (SCPR). The SCPR can, unlike conventional instruments, provide a drift free continuous estimate of height changes on the summit of Axial Volcano. The SCPR measurements will aid in understanding the processes occurring within Axial Volcano, and enable forecasts of future eruptions. These measurements are but one component of a larger investigation at Axial Volcano, and directly complements and supports other research efforts. The project supports the training of a Ph.D. student. Our knowledge of seafloor volcanoes is much more limited than our knowledge of continental volcanoes. Axial Volcano in the Northeast Pacific appears to be accelerating in its eruption cycle. Eruptions in 1998, 2011, and 2015 have been observed with sparse geodetic coverage. This coverage is increasing now that the OOI Cabled Array is in operation at Axial Volcano. Uplift rates preceding the two most recent eruptions are much higher than before, indicating an increase in magma supply. This project will install a continuously operating instrument, the Self-Calibrating Pressure Recorder (SCPR) on the OOI Cabled Array. The SCPR can provide drift free pressure measurements (using an internal drift free pressure reference), which in turn can be used as proxies for vertical deformation. The vertical deformation measurements can be used to better constrain models of magma eruption volume and recharge rates. Additionally, the SCPR can serve as a reference station for other geodetic arrays and surveys, including Remotely Operated Vehicle campaign pressure surveys and Autonomous Underwater Vehicle repeat bathymetric mapping. There are many potential applications of this technology to other disciplines, including physical oceanography for detecting decadal scale processes as well as sea level change.