IRIS DMC Data Center Measurement Stats

Read the description of method for details of how the measurments are conducted.

Last 24 hours (updated hourly):

Last 48 hours (updated hourly):

Last 7 days (updated daily):

Last 31 days (updated daily):

All time (updated daily):


The IRIS DMC monitors the status FDSN data centers by requesting small amounts of time series data from their fdsnws-dataselect web service interfaces.

Measurement sites: 7 geographically dispersed sites independently send measurement requests to each monitored data center. Measurement sites include: IRIS DMC (Seattle, WA), IRIS ADC1 (Livermore, CA), UNAVCO (Boulder, CO), UCSD (San Diego, CA), LDEO (Palisades, NY), SED (Zurich, Switzerland), IRIS HQ (Washington DC).

Measurement interval: each measurement site sends a request every 5 minutes to each monitored data center.

Measurement results: all measurements are aggregated at the IRIS DMC into the following classifications:

UP - At least 3 measurements total and at least one of them was successful.
DOWN - At least 3 measurements total and all of them were unsuccessful.
No measurement - Less than 3 measurements are available.
The classification is biased towards indicating that a data center is UP. Partial measurement failures are not indicated in the aggregated results as a single positive measurement results in UP. Obviously, down time in-between the measurements are not recorded. On the other hand, when an aggregate result is DOWN it is a very strong indicator that the data center's service was unreachable by anyone.

Measurement details

Each measurement is a small time series request, specific to each data center. Theses are the requests used:

NCEDC    -
SCEDC    -
RESIF    -
SED      -
INGV     -
BGR      -
LMU      -
USPSC    -
KOERI    -
IPGP     -
NIEP     -
NOA      -