Working Group on Long-Term Seafloor Seismographs (WGLTSS)

Charge to the Long-Term Seafloor Seismograph Working Group

The scientific needs of global and regional seismology require long-term (~permanent), highquality, telemetered seismic observations from key seafloor sites in order to complement existing high-quality stations on land. This working group will take the first steps towards developing a pilot project for installation of a high-quality permanent seismic network in the open ocean. This is a working group of the GSNSC with ties to the OBSIP oversight committee and the Instrumentation Services SC, and will define the key elements of a small pilot network that could be proposed to an appropriate funding agency. The committee will report to the GSNSC, with the written report also forwarded to the OBSIP oversight committee and the ISSC for discussion.

Working Group Tasks

  1.  The working group shall consider the GSN design goals to map how these goals translate to the seafloor. The seafloor is a much different environment with unique technical challenges and thus requires some modification of goals set for land stations. The working group will prioritize the design goals, identify likely tradeoffs, and signpost the development of a feasible project within a 5-10-year time frame.
  2.  Conceptualize the operations for a pilot project to operate a GSN-like station on the seafloor. This may include:
    1. Identify several potential locations for a pilot station(s) on the seafloor based on science needs for imaging global earth structure and observing seismic sources.
    2. Investigate models of operations and maintenance.
    3. Identify instrumentation and station configuration needs.
    4. Investigate whether/how ships of opportunity can be used to minimize logistical cost.
  3. Identify any similar or relevant activities occurring within the U.S. and in international OBS communities.
  4. Identify relevant OBS and telemetry technology (with specific consideration of important requirements for the spectral response). Prioritize the need for telemetry relative to additional cost.
  5.  Review the literature and access the archive of publicly available broadband OBS data, as needed. Summarize the characteristics of high-quality sites for installation and instrumentation strategies. Identify any further quantitative analyses that may be required. The deep oceans require an installation strategy that will differ vastly from highly controlled GSN installations on land. However, in several instances OBSIP experiments have provided vastly improved long- period performance from broadband sensors through next-generation hardware, deployment methods, and data processing techniques.

6. Write a report summarizing the findings.

Membership

  • Jeffrey Park (GSNSC chair)
  • Monica Kohler, chair (GSNSC member)
  • Jessica Irving (GSNSC member)
  • Bob Woodward (IRIS, Director of Instrumentation Services)
  • Katrin Hafner (IRIS, GSN Program Manager)
  • Barbara Romanowicz (member at-large)
  • Jackie Caplan-Auerbach (OBSIP oversight committee member)
  • Anne Trehu (ISSC representative)
  • Jon Berger, Ex-officio (GSNSC member)
  • John Collins, Ex-officio (OBSIP IIC representative)

Milestones and Outcomes

  • Short presentations at the following meetings:
    • Town Hall on “International Ocean Bottom Seismometer Experiments and Data” during AGU on December 12, 2016. (Completed)
    • Poster (and oral presentation if planning committee is interested) at the OBSIP Symposium in September 2017.
    • SIG dedicated to WGLTSS during AGU, December 2017. These meetings are expected to provide good venues for letting others know what the global seismology community is planning, and to gather information about other international activities.
  • Submittal of working group report to Seismological Research Letters, IRIS Newsletter, or similar publication.
  • Written Report to be completed October 2018

Term

June 2017 to October 2018: The GSN has $5K in its SAGE YR4 budget that was approved by the IRIS BoD for this activity. Meetings will initially take place virtually, via conference calls or go-to-meeting sessions.

Action Items

2017 Jul