Data Services Newsletter

Volume 5 : No 2 : April 2003

The Possible Impact of the USArray Project on the DMC

(text extracted from the EarthScope proposal document)

In February of 2003, the US President signed into law the long-awaited Omnibus Spending Bill for fiscal year 2003. Included within the Bill is $30 million to fund the first year of EarthScope.

Among the fundamental principles underlying the collection and distribution of EarthScope/USArray data are that:

  • All data will be freely and openly available to all interested parties.
  • Wherever possible, data will be collected and distributed in near-real-time.
  • Data (including both time series from sensors and associated metadata) will be reviewed to ensure quality.
  • All data will be archived at the IRIS Data Management Center (DMC).
  • All data will be distributed by the IRIS DMC using both traditional and newer Data Handling Interface (DHI)-based data distribution methods.

USArray will roughly double the DMC’s current rate of data collection and archiving. Because of the modular hardware configuration and highly automated procedures established at the DMC, this increase in data flow can be incorporated with relatively minor increases in staffing and hardware.

For more about the expected impact of this data flow to the DMC, review this PDF version of the Data Management section of the recent EarthScope proposal (extracted from the complete report available at

Planned data flow of the USArray
Figure 1: Planned data flow impact of the USArray: RTDN – Real Time Distribution Node, ANF – Array Network Facility

by Tim Ahern (IRIS Data Management Center)

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