Character of seismic motion at a location of a gas hydrate‐bearing mud volcano on the SW Barents Sea margin. Issue 8 (14th August 2014)

• Record Type: Journal Article
• Authors: Franek, Peter; Mienert, Jürgen; Buenz, Stefan; Géli, Louis
• Is Part Of: Journal of geophysical research. Volume 119:Issue 8(2014:Aug.)
• Page Start: 6159
• Page End: 6177
• Publication Date: 2014-08-14
• Subjects: Håkon Mosby mud volcano -- seismic activity -- harmonic tremors -- tidal correlation -- earthquakes -- mud eruption; Geomagnetism -- Periodicals; Geochemistry -- Periodicals; Geophysics -- Periodicals; Earth sciences -- Periodicals; 551.1
• DOI: 10.1002/2014JB010990
• Languages: English
• ISSNs: 2169-9313

Abstract

Abstract: The Håkon Mosby mud volcano (HMMV) at 1270 m water depth on the SW Barents Sea slope has been intensively studied since its discovery in 1989. A variety of sensors monitored morphological, hydrological, geochemical, and biological parameters in the HMMV area. An ocean bottom seismometer deployment allowed us to register seismic motion for 2 years, from October 2008 to October 2010. The analysis of seismic records documents two types of seismic signals. The first type are harmonic tremors with frequency peaks around 4–5 and 8–10 Hz that occur in swarms. Their origin could be from fluid flow circulation or resonant vibrations of gas bubbles or from delayed movement of fluid‐rich sediments in the conduit or in a deeper pseudo‐mud chamber of the HMMV. Because swarms occur with a periodicity of ~ 6 h, tide‐related effects are suspected to influence the mechanism originating the tremors. The second type of signals are regional earthquakes that were in 15 cases recognized in seismic records. The activity of harmonic tremors was not significantly affected by earthquakes. Key Points: Processes in the mud volcano are the source of harmonic waveforms or tremors Harmonic tremors occur in swarms with a periodicity of 6 h Activity of the Håkon Mosby mud volcano is not affected by earthquakes