Earth and Space Science (Dec 2019)

Ocean Observatories as a Tool to Advance Gas Hydrate Research

  • M. Scherwath,
  • L. Thomsen,
  • M. Riedel,
  • M. Römer,
  • D. Chatzievangelou,
  • J. Schwendner,
  • A. Duda,
  • M. Heesemann

DOI
https://doi.org/10.1029/2019EA000762
Journal volume & issue
Vol. 6, no. 12
pp. 2644 – 2652

Abstract

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Abstract Since 2009, unprecedented comprehensive long‐term gas hydrate observations have become available from Ocean Networks Canada's NEPTUNE cabled ocean observatory at the northern Cascadia margin. Several experiments demonstrate the scientific importance of permanent power and Internet connectivity to the ocean floor as they have advanced the field of gas hydrate related research. One example is the cabled crawler Wally at Barkley Canyon, enabling live in situ exploration of the hydrate mounds and its associated benthic communities through the crawler's mobility and permanent accessibility throughout the year. Another example is a bubble‐imaging sonar at Clayoquot Slope, revealing the strong relationship between ebullition of natural gas and tidal pressure, without apparent correlation to earthquakes, storms, or temperature fluctuations, in year‐long continuous recordings. Finally, regular observatory maintenance cruises allow additional science sampling including echo‐sounder surveys to extend the observatory footprint. Long‐term trends in the data are not yet apparent but can also become evident from continuous measurements, as ocean observatories such as NEPTUNE are built for a 25‐year lifetime, and expansion of the observatory networks makes these findings comparable and testable.

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