Geospatial warning systems
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Project > Methodologies > Oceanographic and Geophysical Surveys
Oceanographic and Geophysical Surveys
The Ocean Floor Mapping System Using Sea Beam
Seismic Monitoring (The Generation of a Regional Velocity Model)
Seismic monitoring is the key method in any geodynamically active volcanic field because of its wide range of application. For this reason, a continuous seismic monitoring system was established in the Kos - Yali - Nisyros - Tilos volcanic field consisting of nine land and six ocean bottom seismic stations (see Fig. 1).
The following aspects were considered as part of this section of the project:
1. Location of earthquake sources with an accuracy of better than a few hundred meters, in order to relate eruptive-tectonic behaviours. This resolution requirement constrains the type of sensors, i.e. to several three-component velocity-meters and ideally a spatial array of sensors.
2. Instrumentation was chosen to maximize the dynamic range, in order to be
able to detect the faintest, negative magnitude earthquakes and correctly record
larger earthquakes (magnitude 3 and over), or earthquakes closer to the location
of the monitoring equipment.
Fig. 14 Regional velocity model down to 30 km depth, shown
as cross-section of the Kos-Yali-Nisyros-Tilos volcanic field. University of
Hamburg (UHIG), GeoPro and NOAIG
The Regional Seismic Velocity Model (Fig. 14)
The sedimentary succession is typically 4 to 5 km thick. The sedimentary layers
are flat laying but show significant dips in the Kos-Nisyros volcanic area.
The 160,000 year old Kos Plateau Tuff volcanic caldera could be conclusively
identified by the geometry of the sedimentary sequences, which cover an area
of 30 x 40 km with a depth between 0.8 to 1.0 km.
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