Welcome to the NOAA Institutional Repository |
Stacks Logo
Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.
Clear All Simple Search
Advanced Search
Posteruption Enhancement of Hydrothermal Activity: A 33-Year, Multieruption Time Series at Axial Seamount (Juan de Fuca Ridge)
  • Published Date:
  • Source:
    Geochemistry, Geophysics, Geosystems, 20(2), 814-828.
Filetype[PDF-7.37 MB]

This document cannot be previewed automatically as it exceeds 5 MB
Please click the thumbnail image to view the document.
Posteruption Enhancement of Hydrothermal Activity: A 33-Year, Multieruption Time Series at Axial Seamount (Juan de Fuca Ridge)
  • Description:
    Abstract Mid-ocean ridge eruptions, initiating or revitalizing hydrothermal discharge and disrupting seafloor ecosystems, occur regularly as a consequence of plate spreading. Evaluating their impact on long-term hydrothermal discharge requires information on the scale and duration of any posteruption enhancement. Here we describe a unique hydrothermal plume time series of annual (or more frequent) observations at Axial Seamount vent fields from 1985 through 2017, missing only 7 years. Axial, a hot spot volcano astride the Juan de Fuca Ridge, experienced eruptions in 1998, 2011, and 2015. In 1998 and 2011 lava flooded the SE caldera and south rift zone, but in 2015 most lava was extruded in a series of flows extending ~20 km down the north rift zone. Response cruises occurred within 18 days (1998) to about 4 months, followed by regular posteruption observations. All 30 cruises measured plume rise height (a proxy for heat flux) and turbidity (indicative of chemical changes in vent discharge) at several vent sites, yielding an integrated view of vent field activity. Venting in the SE caldera area persisted throughout the time series, consistent with the imaged location of the shallowest portion of the melt-rich magma reservoir. Eruptions produced substantial and diagnostic increases in plume rise and turbidity, and posteruption enhancements lasted 2–5 years, totaling ~10 years over the course of the time series. Estimates of the relative heat flux indicate a sixfold increase during eruption-enhanced periods, implying that generalizations about mid-ocean ridge hydrothermal fluxes may be underestimates if based on non–eruption-enhanced hydrothermal activity alone.
  • Document Type:
  • Main Document Checksum:
  • Supporting Files:
    No Additional Files
You May Also Like: