Working Group on the Design Goals for the Global Seismographic Network

Charge to the Working Group on GSN Design Goals

The creation of this Working Group (WG) is motivated by the findings of the 2015 external review of the GSN.  From the external-review report:

The original [GSN] design goals have largely been met, although there are important exceptions. Developments in seismographic instrumentation generally have kept pace with the needs of the research and monitoring communities. However, in recent years, novel analyses of GSN data, new array deployment strategies, and improvements in seismographic and other geophysical instrumentation have led to new discoveries across a range of solid-­earth deformation phenomena. These new discoveries, including the “Grand Challenges in Seismology” enumerated in a recent report, suggest that the design goals for the GSN should be revisited in the context of both research and monitoring.

The first recommendation to IRIS by the external review is (we boldface the key sentence):

To date, the established design goals have served both the research and monitoring communities well, and their stability over time has provided a stable target for technical innovation. However, design goals should be continuously evaluated in response to the evolution of research and monitoring needs. IRIS should establish a procedure that monitors community needs and technical innovation and reevaluates GSN design goals in response. Changes to design goals should occur on a timetable that allows strategic study, planning, deployment and assessment, that is, it is important that the GSN have a stable configuration for a significant (decadal, for example) period of time but not long enough to delay important design changes in response to scientific and monitoring needs.

The GSN Standing Committee proposes to establish this working group in response to this recommendation.  The WG would mainly meet by conference call, email and face-to-face gatherings at AGU meetings and the IRIS Workshop.

Working Group Tasks

The GSN design goals were originally formulated in 1985, and revised in 2002.  The WG is tasked primarily with updating the design goals in light of new technologies in motion sensors, data-acquisition systems, data-analysis algorithms, and the siting of long-term seismographic stations in extreme environments.  

Review of Existing Design Goals in Light of Current Scientific and Monitoring Uses:

  1. Update GSN Design Goals to meet the evolving needs and challenges facing basic science and earthquake monitoring.
  2. Update aspects of the 2002 GSN Design goals, based on advances in 21st century technology capability, e.g. sensor and data-acquisition hardware, low-power systems, and telemetry options.
  3. Assess the design goals and corresponding rationale for auxiliary equipment currently deployed at some GSN stations, such as microbarographs, infrasound sensors and other geophysical sensors.
  4. Update Design Goals to allow for corrections (e.g. tilt effects) to be made at GSN sites that have large natural noise sources, e.g., ocean-island stations.
  5. Address whether the current design goals address the challenges of long-term stations sited on land-based ice sheets, e.g. in Greenland or Antarctica or other extreme environments.

Design Goals for the Next Generation GSN System:

  1. Long-Term Seafloor Seismographic Stations:  What alterations/additions to the GSN Design Goals should be made for these stations? (This question will largely be addressed by the Working Group on Long-Term Seafloor Seismographs. Its deliberations will transfer to this WG through its shared members and its formal report to the BOD.)
  2. Addition of the Broad-Band Array Capability to facilitate the ability to perform Frequency-Slowness Stacking and Migration of Seismic Phases:   This includes defining how many GSN stations should have arrays, how many stations should be in an array, and how wide the array’s aperture should be.


 Milestones and Outcomes:

  1. Short presentations at the following meetings:
    1. SIG at the 2019 SAGE-GAGE Workshop
    2. SIG dedicated to GSN Design Goals during AGU Fall Mtg, December 2019.
    3. Poster at the 2020 EGU meeting, fronted by any WG member who attends (cancelled due to Pandemic) - Virtual Meeting held with Global Seismic Network Operators)
  2. 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.
  3. Submittal of working group report to Seismological Research Letters, IRIS Newsletter, or similar publication.
  4. Written Report to be completed April 2021


May 2019 to April 2021:  Meetings will initially take place virtually, via conference calls or go-to-meeting sessions.

Meeting Minutes and Action Items