Multidisciplinary Oceanic Information SysTem (MOIST) INGV Integrated Systems for Marine Environmental Infrastructures (SIIAM) paolo.favali@ingv.it 1 0 999999 SMO 1 - Seismometer 2012-06-10T00:00:00+00:00 2013-06-12T19:52:30+00:00 15.397500,37.547650,-2036.6 Web page: <a href='http://www.moist.it/sites/western_ionian_sea/2/SMO1/seismometer/35'>MOIST dataset metadata</a> Area: East Sicily Instrument: Guralp CMG-1T 3 component broadband seismometer (360 s-50 Hz) Period: June 10, 2012 - June 12, 2013 Abstract: This digital database comprises seismological data recorded during the SMO project by a 3 component broadband seismometer. The sensor was installed on the the NEMO-SN1 (Neutrino Mediterranean Observatory - Submarine Network 1) seafloor observatory, offshore of the Eastern coast of Sicily (Southern Italy) at a depth of 2036 m. The seismometer is installed in a dedicated vessel integrated in a separate structure connected to the observatory via a special mechanical release. To guarantee a good coupling with the sea bottom, the structure is disconnected just after the observatory touch-down and kept linked to the frame by a slack rope (Favali et al., 2006). The sensor is connected to a 24 bit digitizer on the observatory. The GPS signal is transmitted underwater to the digitizer, so that the data packages are time-stamped locally. Purpose: This project is a continuation of GNDT 1 and GNDT 2 where the main objective was to establish a multiparameter seafloor observatory off-shore eastern Sicily. One of the main aspects of SMO remains long-term geophysical monitoring and broad-band seismic measurements from this site is of great interest given its proximity to the Etna volcano (~ 50 km) and to offshore seismogenic structures where some of the most destructive earthquakes in Italy took place (some of them generated tsunamis). For this reason a tsunami detection systems is implemented on-board the observatory and the seismometer is an important component. Quality of data: The Z (vertical) and N components have recorded data of good quality for the duration of the deployment. The E component recorded only electronic noise from the beginning of the experiment till the 24th of August (~9 UTC) due to the fact that the mass was not released. After we were able to release the mass the E component recorded good quality signal for the rest of the mission. Due to tests, during June 2012, there are periods with electronic disturbances and presence of gaps in the data. A periodic disturbance is visible on all components due to the acoustic signal emitted when the ADCP is sampling (2 profiles/hour).