Monterey Bay broadband Ocean Bottom Observatory (MOBB)

This is a collaborative project between the Berkeley Seismological Laboratory (BSL) and the Monterey Bay Aquarium Research Institute (MBARI) PI's are Barbara Romanowicz at UC Berkeley and Paul McGill at MBARI. A three component very broadband seismometer package (CMG-1T), recording system, as well as auxiliary differential pressure gauge (DPG) and current meter, were installed on the seafloor, in Monterey Bay, 40 km off-shore, at 1000m water depth, in April of 2002. The seismic package was installed in a PVC pipe using the MBARI ROV Ventana and is buried under the seafloor, covered with glass beads. The recording system and battery package sits 10m away in an anti-trawling device, whose design served as prototype for the housing of the MARS cable junctions (see: http://www.mbari.org/mars). The MOBB observatory is currently autonomous: data cartridges and batteries are exchanged every 4 months using dives of the ROV Ventana from the MBARI ship Point Lobos. We are currently working on hardware and software to connect the observatory to the MARS cable. Once connected, the data from MOBB will be combined in real-time with the data from the landbased broadband network in northern California. For more information on the project, see the MOBB page at MBARI:", as well as the following papers:

  • Romanowicz, B., D. Stakes, R. Uhrhammer, P. McGill, D. Neuhauser, T. Ramirez, D. Dolenc (2003) "The MOBB experiment: a prototype permanent off-shore ocean bottom broadband station," EOS Trans AGU, 84, 325-332.

  • Romanowicz, B., D. Stakes, D. Dolenc, D. Dolenc, P. McGill, R. Uhrhammer and T. Ramirez (2006) The Monterey Bay Broadband Ocean Bottom Seismic Observatory, {\it Annals of Geophysics}, http://hdl.handle.net/2122/1067

    • For all enquiries, please contact Barbara Romanowicz:
    barbara@seismo.berkeley.edu
     

     

    See also information on the "Moise experiment" below.

     

    Location of the MOBB station (red star) with respect to nearby station of the Berkeley Digital Seismic Network (BDSN, blue squares), NOAA buoys (Yellow circles) and major faults (red lines).


     

    Left: The MOBB seismometer package is being installed in a PVC pipe on the ocean floor, using the arm of the ROV Ventana. Right: the underwater connector from the seismometer package is being carried by the ROV Ventana to the anti-trawling mount containing battery and recording package. The cover of the anti-trawling mount can be removed and the package brought back to the surface and exchanged for a new one. This has been occurring every 3-4 months since the installation in April 2002.


    Publications related to MOBB data analysis

    The MOBB data have been used for a variety of purposes.


      Two sources of background noise are particularly problematic in ocean bottom broadband seismic deployments:

    1) long period noise in the infragravity wave band and
    2) signal generated noise due to reverberations in the sediment column.

    We explored these two issues in the following paper:

  • Dolenc, D., B. Romanowicz, R. Uhrhammer, P. McGill, D. Neuhauser and D. Stakes (2006) Identifying and Removing Noise from the Monterey Ocean Bottom Broadband Seismic Station (MOBB) data, {\it G-cubed}, 8, doi:10.1029/2006GC001403.
    See also BSL Annual report for more detailed information

    • Documenting the origin of the infragravity wave noise and its relation to ocean storms and ocean waves as well as the earth's hum have been explored in the following papers:

  • Dolenc, D., B. Romanowicz, D. Stakes, P. McGill and D. Neuhauser (2005) Observations of infragravity waves at the Monterey Ocean Bottom broadband station (MOBB), {\it Geochem, Geophys. geosyst.}, 5, Q09002, doi:10.1029/2005GC000988.
    See also BSL Annual report for more detailed information

  • Dolenc, D., B. Romanowicz, P. McGill and W. Wilcock (2008) Observations of Infragravity waves at the Ocean-Bottom Broadband seismic stations Endeavour (KEBB) and Explorer (KXBB), G-Cubed, 9, doi:10.1029/2008GC001942.
    See also BSL Annual report for more detailed information.

    • The MOISE experiment

    This project follows a 3 months deployment in 1998 of a "half-buried" broadband seismic package in a similar location in Monterey Bay. This temporary deployment, MOISE (MOnterey Ocean bottom International Seismic Experiment) was a collaboration between MBARI, the Institut de Physique du Globe in Paris (IPGP), the Universite de Bretagne Occidentale (UBO), and the Berkeley Seismological Laboratory. The seismic package and recording system was installed with the help of the ROV Ventana, and featured the first underwater connections, performed from the ship Point Lobos, between the seismometer package, and recording and battery packages. The first time around, it took 3 hours for the Point Lobos operators to successfully achieve the connection. The experience gained led to a redesign of the topology of the interfaces, more practical for maneuvering with the ROV. For MOBB it now takes about 10 mn to disconnect and reconnect the seismometer package to the recording/battery system. The MOISE experiment also showed the importance of burying the seismometer package under the seafloor to reduce the influence of ocean bottom currents, leading to the MOBB design.

    The MOISE deployment also included a 3 component electromagnetic package, which was deployed independently directly from the ship. For more information about MOISE and the data produced, see the following papers:

  • Stakes, D., B. Romanowicz, J.P. Montagner, P. Tarits, J-F. Karczewski, S. Etchemendy, D. Neuhauser,P. McGill, J.C. Koenig, J.Savary, M. Begnaud, M. Pasyanos (1998) "MOISE: Monterey Bay Ocean Bottom Intermational Seismic Experiment", EOS Trans AGU, 79, 301-309.

  • Romanowicz, B., D. Stakes, J.P. Montagner, P. Tarits, R. Uhrhammer, M. Begnaud, E. Stutzmann, M. Pasyanos, J-F. Karczewski, S. Etchemendy, D. Neuhauser (1998) "MOISE: A pilot experiment towards long term sea-floor observatories," Earth, Planets and Space, 50, 927-937.

  • Stutzmann, E. JP Montagner, et al. (2001) "MOISE: A prototype multiparameter Ocean-bottom station", Bull. Seism. Soc. Amer., 91, 885-892

  • Stakes, D. S., B. Romanowicz, M. Begnaud, K. McNally, J.P. Montagner, E. Stutzmann and M. Pasyanos (2002) "The MBARI Margin Seismology Experiment: A prototype seafloor observatory ", in "Science-Technology Synergy for Research in the Marine Environment: Challenges for the XXI Century, L. Beranzoli, P. Favali and G. Smirglio, Eds, Developments in Marine Technology, 12, 93-110.


    • Last update: 30 May 2008.