GNSS reference station seismic monitoring

Saba and St. Eustatius (‘Statia’) are volcanic islands in the Caribbean Netherlands (Dutch Carribean). Due to subduction of the North and South American Plates under the Caribbean Plate, this region has active volcanoes. The KNMI (Koninklijk Nederlands Meteorologisch Instituut) uses the PolaRx5S and PolaRx5 GNSS receivers, seismometers and temperature sensors to monitor the activity of volcanoes Mt. Scenery on Saba and The Quill on St. Eustatius.

The ionospheric monitoring capabilities of PolaRx5S receivers are also used to collect measurements for space weather research. These receivers located on Saba and Statia are part of a vast space weather monitoring network together with PolaRx5S receivers from INGV (Italian National Institute of Geophysics and Volcanology), which monitor ionospheric scintillations in regions of heightened solar activity such as around the equator and at the poles.

GNSS observations are well suited to help monitoring active volcanoes.

Elske de Zeeuw - van Dalfsen

Scientist at R&D Dept. Seismology and Acoustics, KNMI

In the past 5 years KNMI installed 2 monitoring sites equipped with PolaRx5S reference receivers and PolaNt Choke Ring B3/E6 antennas and 6 sites with PolaRx5 reference receivers. Signals from multiple GNSS constellations are used to calculate the location of each antenna with high accuracy, sufficiently precise to detect minute motions caused by tiny deformations of the volcanic bedrock and surface. With the combined seismic and GNSS monitoring network, KNMI can actively monitor the volcanoes, the seismic activity and contribute to tsunami warnings in the Dutch Caribbean.

GPS/GNSS antenna siesmic monitoring Statia

Images above from left to right show the following:

PolaNT Choke Ring B3/E6 antenna at St. Eustatius, with the Quill volcano in the background.
Installation of a GNSS monument in volcanic bedrock.
GNSS time series from a monitoring site on Saba.

The Royal Netherlands Meteorological Institute (in Dutch KNMI or Koninklijk Nederlands Meteorologisch Instituut) is the Dutch national weather service, which has its headquarters in De Bilt, in the province of Utrecht, The Netherlands. The primary tasks of KNMI are weather forecasting and monitoring of weather, climate, air quality and seismic activity. KNMI is also the national research and information centre for meteorology, climate, air quality and seismology.