Starting around 2017-02-17 16:20 UTC (11:20 EDT / 8:20 PDT) IRIS Data Services experienced a network outage. We are still looking into the cause of the outage and hope to be back online as soon as possible. We apologize for the inconvenience to your workflow.
Calibrations on USArray TA data are run within a few days to weeks both after sensor installation and before sensor removal (if possible). The signal looks like large amplitude white noise with an abrupt start and end and lasts for about 2 hours. Two examples are illustrated below: