A primary infrasound station of the International Monitoring System (IMS) CTBTO “Aktyubinsk” IS31 (IS31KZ) is located at Tassay settlement of Chromtayu region, Aktyubinsk area. The station was constructed in 2001, the KNDC archive has the station’s data from December 2003.
The detailed information can be found at: here
Until the fall of 2019 the infrasound sensors – microbarometers МВ2000 together with Aubrac digitizers were installed in the bunkers. In total, there were eight such equipment vaults. Systems H and L differed by device construction for wind interference suppression. In the fall of 2019 there was thorough upgrade of the station. Another ninth element was added, the wind suppression systems were unified. The microbarometers were replaced with MB-3. The meteorological station was installed at the station. The sample rate is 20 samples/sec/channel. Time scale is GPS. Infrasound data are transferred to the Center Processing Facility via fiber optic lines , and then together with seismic data of AKTO station to the IDC via a satellite channel.
Below are some parameters of the Aktyubinsk station (IS31/I31KZ):
| Site # | Seismometer, type | Borehole depth, m | Latitude | Longitude | Elevation above sea level, m | Notes |
| H1 | MB3 | 0 | 50.40690°N | 58.03485°E | 367 | |
| H2 | MB3 | 0 | 50.40861°N | 58.03431°E | 367 | |
| H3 | MB3 | 0 | 50.40759°N | 58.03838°E | 367 | |
| H4 | MB3 | 0 | 50.40496°N | 58.03688°E | 368 | |
| H5 | MB3 | 0 | 50.40338°N | 58.03428°E | 373 | |
| H6 | MB3 | 0 | 50.40601°N | 58.03340°E | 369 | |
| H7 | MB3 | 0 | 50.41322°N | 58.04816°E | 365 | |
| H8 | MB3 | 0 | 50.39694°N | 58.03779°E | 360 | |
| H9 | MB3 | 0 | 50.41019°N | 58.01769°E | 372 |
Response and phase characteristics of the installed microbarometers are:
Configuration of “Aktyubinsk” infrasound station (IS31, I31KZ):
