Swedish National Seismic Network

The Swedish National Seismic Network (SNSN) started with the installation
of a Wiechert seismograph in Uppsala in 1904. Since 1998 the SNSN is a
part of the Department of Earth Sciences at Uppsala University. The SNSN
operates the only permanent, earthquake focused seismic network in Sweden
and is responsible for detecting and recording earthquakes in Sweden.
Near real-time automatic event detection has been an integral part of SNSN
operations since 2000 and continuous 100 Hz data has been collected since
2008. Information services is an important part of SNSNs operations, which
includes automatic risk assessment of large global events to Swedish
crisis management authorities, contacts with the authorities, information
to media and the public and outreach to schools. The SNSN operates 65-70
permanent stations, from Lund in southern Sweden to north of Torneträsk.
Approximately one-third of the instruments are 120 s and two-thirds 30 s,
sampling at 100 Hz. The sensors have unusually
high gain, mostly 2x10,000 V/m/s, in order to facilitate detection of
microearthquakes in the regional size network. With an average station
spacing of approximately 65 km, the SNSN is complete to magnitude 0.5 within the
network. The SNSN exports real-time data from 10 stations to ORFEUS and
additional real-time data from stations along the borders to the Danish,
Finnish and Norwegian seismic networks. For inquiries about data from
other stations than the ones exported to ORFEUS, please contact the
SNSN.