The international long-term experience in active volcanoes has demonstrated that the seismic method is one of the most effective monitoring methods.

It is based on the principle that as magma rises to the surface, it causes micro-earthquakes that can be recorded with high accuracy by the seismographs of a specially configured and installed local network. The precise location of the origins of such micro-earthquakes and the determination of their possible migration allows the detection of the position of the ascending magma in each instance, the rising rate and the possible outlet, within a sufficient time frame prior to the manifestation of volcanic action.

This is achieved through the installation of a permanent seismology network comprising significant number of seismographs (seismometers), located in selected points in the region.

The current seismic network of Nisyros consists of four three – directional seismographs installed at Stavros, Nikia, Spiliani and NE Yali. Each seismograph includes a solar cell for battery charging purposes and a proprietary telemetry system for transmission of analog signals to the main station using a suitable antenna.

The main station is located at the Observatory, in Emporeio. The roof of the Observatory includes the antennae receiving analog signals, used for internal transfer and logging of seismic events.

The recorded events are inspected and decoded on a daily basis by the local observer, according to the specifications of the Geophysics Laboratory of the Aristotle University of Thessaloniki.

The recordings of the seismology network, constituting the main tools for the appropriate, permanent monitoring of the Nisyros volcano, are then transmitted via satellite to the Seismology Station of the University of Thessaloniki, the latter ensuring round-the-clock supervision for all the signals from the Nation-wide earthquake monitoring network of Aristotle University.