Unit Affiliation: Marine and Polar Geophysics, Lamont-Doherty Earth Observatory (LDEO)
This research will continue measurements of long term volcanic inflation of the seafloor at Axial Seamount on the Juan de Fuca Ridge using an innovative new pressure sensor/benchmarking method. Present data show Axial Volcano has been re-inflating since its 1998 eruption. The center of Axial caldera has been uplifted 2.4 m since then. At the current rate of inflation, it is estimated that in another 4-8 years Axial will be fully inflated and ready to erupt again. Axial volcano is the only underwater volcano in the world where inflation and deflation is being measured, where the magma supply rate can be quantified, and where an entire volcanic cycle can be documented. Data from the project will be able to be used to constrain the depth of magma movements beneath the caldera, show how the magma supply rate changes over time, and help determine whether or not eruptions can be forecast. Measurements of the volcano will be made in 2009 and 2011 at an array of seafloor benchmarks inside and outside the caldera using a remotely operated vehicle. The measurements follow a NOAA funded survey in the summer of 2007 and will provide inflation data every two years until 2011. Data will then be compared to other volcanic regions and used to optimize crustal deformation models. Goals will be to determine whether the inflation rate follows an exponential decay that is governed by the pressure gradient between a deep source that supplies magma to the shallow reservoir beneath the caldera. It will also seek to determine if magma delivery is focused, supplied at a higher rate, and stored in a deeper and larger reservoirs than at normal mid-ocean ridge segments.
OUTCOMES: Found that Axial was inflating at about 15cm a year and had inflated 2.4m since its last eruption. It erupted again in 2011 so now it is the only seafloor volcano that has been measured through its entire cycle.
Collaborative Research: A MCS Investigation to Study Axial Crustal Structure and Alteration of Upper Crust at the Juan de Fuca Spreading Center