The Montserrat Volcano Observatory was established in 1995 to monitor the activity of the Soufrière Hills volcano on Montserrat, in the Caribbean.
Currently operated by staff from the Government of Montserrat and the British Geological Survey, the Montserrat Volcano Observatory is based in a purpose-built facility 6 km from the volcano.
The MVO's role is to monitor and predict volcanic activity on Montserrat, and to advise the authorities of potential risk.
In early 2005, the MVO installed 10 high dynamic range CMG-40T seismometers in shallow postholes around the volcano, together with a CMG-3TB weak motion borehole installation.
Each CMG-40T instrument is connected to a CMG-DM24 digitizer and spread spectrum radio unit, which transmits seismic data direct to the MVO facility. The instrumentation is entirely powered by solar panels, backed up with 12 V batteries, so that each location operates autonomously.
Layout of the stationAt the CMG-3TB site, a weather recording station provides temperature, pressure and humidity information which is digitized by an additional CMG-DM24 module. Data from this and the 3TB's own digitizer module are combined on site by a CMG-SAM before being transmitted over the radio link.
Data streams are received at the MVO's central facility by a PC running Scream! 4.1 and converted to Earthworm format using the scream2ew module.
The Earthworm system performs calculations on the streams to determine triggers using carlstatrig for individual instruments and carlsubtrig for network triggering. Triggers are recorded and passed to a custom cellphone alarm system. The RSAM seismicity is also calculated and used to trigger the alarm system.