1. Introduction

The IRIS-managed Seismological Facilities for the Advancement of Geosciences and EarthScope (SAGE) provided a suite of community-governed, multi-user facilities for instrumentation and data management to support research and education in seismology and geophysics, while inspiring careers in the Earth sciences.

This award funded the continued operation, maintenance, and improvement of the 150-station Global Seismographic Network, in collaboration with the US Geological Survey (USGS) and many international partners. Significant effort was placed on increasing data quality and updating stations with very-broadband sensors. This network is a cornerstone for global earthquake monitoring, earthquake source studies, earthquake emergency response, tsunami warning and research on Earth structure.

The SAGE facilities' portable seismic equipment pool supported about 70 temporary field projects annually around the world to image Earth beneath tectonic plate boundaries, stable parts of continents, mountain belts, and volcanoes. In addition to equipment loans for these experiments, the SAGE facility staff provided planning, logistical, instrumentation, and engineering services to the Principal Investigators and their teams to increase the quality of recorded data and the overall success of the projects.

SAGE Data Services continued to collect, curate, and distribute data from NSF-supported projects as well as seismic data from International Federation of Digital Seismograph Networks members, USGS-supported regional networks, and stations operated by partner organizations worldwide. As one of the largest free and open-access scientific archives of globally distributed observational data in the world, researchers in over 150 countries retrieved nearly one petabyte of data annually through web services. SAGE staff also developed data products for use by researchers and the public and provided training to foreign operators on network operation and data management to increase the quantity and quality of data available for research and for national and regional programs in earthquake hazard assessment and mitigation.

In September 2015, the Transportable Array completed its deployment, operation, and demobilization of nearly 1700 temporary seismic stations arranged in a rolling 70-km grid across the conterminous US that began in 2003 as part of the NSF-funded 15-year EarthScope initiative. Over 200 stations were adopted by universities, state agencies and the USGS which greatly increased its monitoring of earthquakes in the Central and Eastern US by retaining and continuing to operate 131 stations. The Transportable Array moved to Alaska and Northwestern Canada in 2015 where, over three summers, 194 new stations were installed in an 85-km grid and 32 existing stations received new sensors. Because of the harsh environment and remoteness of many areas in Alaska and Northwestern Canada, a new sensor emplacement technique and a new station design were developed. Many of the stations were also equipped with weather instruments and soil temperature profilers. COVID-19 travel restrictions resulted in deferred removal and continued operation of stations in Alaska and Northwestern Canada for an additional year. Again, many stations were retained by universities, USGS Alaska Volcano Observatory, and Canadian entities such that only 80 stations required removal during summer 2021. Data recorded by all stations in the Transportable Array network were transmitted within seconds and immediately available for public use from the SAGE Data Center. 

2. Intellectual Merit

Data collected from permanent networks and temporary deployments and distributed through the SAGE facilities form the observational basis for most of the fundamental studies in seismology conducted by researchers at US universities and organizations worldwide. These data, often combined with other geophysical data, help resolve features, processes, and understanding about Earth at scales ranging from the whole Earth to continents and regions to microstructures. The findings from these studies were shared with the scientific community at three IRIS-organized workshops during the first five years, in hundreds of oral and poster presentations delivered by researchers at professional conferences, and published in a wide variety of journals. IRIS and/or SAGE facilities were cited at least 825 times, on average, per year. 

3. Broader Impacts

SAGE Education and Public Outreach continued development of seismology and Earth science resources for classrooms and the public. Products included activities that follow best pedological practices and science standards, animations describing complex concepts, museum displays, slide sets following recent newsworthy earthquakes, and web-based applications that utilize or show seismic data recorded by stations around the world. The growing collection of resources were shared at professional meetings and public events and are freely accessible via the IRIS website (www.iris.edu). The Transportable Array partnered with the Alaska Earthquake Center and the University of Alaska Anchorage to develop and present a for-credit place-based online course for educators about earthquakes and seismology. Overall, the programs and activities enabled by the SAGE facilities advanced scientific understanding of Earth processes, contributed to hazard monitoring and evaluation efforts, and provided learning and professional development opportunities for individuals of all ages in both formal and informal settings.

Last Modified: 06/30/2022
Modified by: Robert L Woodward