A technical issue related to internal epochal time in certain earlier-generation Quanterra data acquisition systems has been identified. The issue will first express itself on December 31, 2017, when the epochal time will cause these systems to cease operating. A second issue, related to GPS time, would express itself in April 2019.

Affected systems are the following: Q380, Q680, Q4120, Q730.

Owing to the age of these systems (they are past their anticipated period of operation), the manufacturer (Quanterra/Kinemetrics) does not maintain an inventory of owners and operators. It is unknown how many of these systems are still in use around the world, collecting valuable data.

The purpose of this communication is twofold:

1) Alerting any operators of these legacy systems of this issue.

2) Identifying legacy systems of this kind around the world, and providing an opportunity for operators of these systems to share and define common concerns.

If you are an operator of one of these systems and would like to participate, please reply to the questions below. We will then create an inventory of affected systems, and share this information within the FDSN. Depending on the number of systems identified, we will then collect and distribute information that may be useful for addressing this issue. Whether the technical issue can be feasibly addressed is not yet known. Any potential action, however, must include as a first step assessing the number of affected operators and systems.

G?ran Ekstr?m, Chair, FDSN
Joe Steim, Quanterra

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Questions:

If you are operating any of the systems mentioned above, please provide:

(1) The number and types of systems.

(2) The serial number(s) of the operating systems.

(3) Existing plans for retiring/replacing these systems before the end of 2017.

(4) If this equipment was acquired or donated from another seismic network, please indicate which network the equipment came from.

Please send the replies to ekstrom@ldeo.columbia .edu