National Western Greece Seismic Network
1. Introduction
GEObit instruments won, (Bid tender, July 2018), the contract for the supply of digitizers to the Seismological Laboratory of the University of Patras (UPSL) [2]. The UPSL replaces old or damaged seismic digitizers with new, state of the art units, integrated with onboard seedlink servers, according to the national regulations of seismic station requirements. Six (6) GEObit SRi32S [1] data-loggers are going to get connected with already existing broadband seismometers.
2. Seismic Network
The National Western Greece Seismic network is part of the Hellenic Unified Seismic Network [3] (HUSN) located in western Greece. It consists of 22 stations (July 2018), some of them in operation and some others, not. During the first phase of the upgrade/replacement, three more stations (PRA, AMPL, DRO) were equipped with GEObit data-loggers. The seismometer is an NMX Trillium120T.
Figure 1
The
Figure 2: The UPSL seismic network and second phase installation GEObit data-loggers (blue triangles)
3. Installations – Second phase
The GEObit data-loggers replaced NMX Trident at station DRO. Stations PRMD and AMPL are new installations.
3.1. The PRMD station
This is a new station located at Pramanta Village in Tzoumerka – Epirus and installed in July 2019. The station is hosted in the region of the local Health Center, getting power and internet connection. The data are transmitted in real time over seedlink using ADSL line.
Figure 3: The PRMD station and GEObit SRI32S data-logger
Figure 4: The PRMD station and GEObit SRI32S data-logger
3.2. The AMPL station
This is a new station located in Ampelaki Village, Etoloakarnania and installed in June 2019. The data are transmitted in real time over seedlink using GSM/3G network
Figure 5 & 6: The AMPL station and GEObit SRI32S data-logger
3.3. The DRO station
This station was equipped with NMX Cygnus/Trillium digitizer and replaced because of malfunction. The seismometer is a NMX Trillium120T.
Figure 7 & 8: The DRO station and GEObit SRI32S data-logger
4. Performance
All three stations are performing extremely well in terms of signal quality, stability and data transmission. The data are acquired by the UPSL with Seiscomp3 software and shared to an Earthworm sever as well. They are also shared to the HUSN over seedlink protocol.
The PSD of the signal is calculated at National Geodynamics Institute of Greece [3]. The heliplots are produced by UPSL Earthworm [2].
4.1. PRMD station Signal and PSD
Figure 9: Typical PRMD Z channel helicorder plot
Figure 10: Typical PRMD Z channel PSD plot
Figure 11: Typical PRMD Y channel PSD plot
Figure 12: Typical PRMD X channel PSD plot
4.2. AMPL station Signal and PSD
Figure 13: Typical AMPL Z channel helicorder plot
Figure 14: Typical AMPL Z channel PSD plot
Figure 15: Typical AMPL Y channel PSD plot
Figure 16: Typical AMPL X channel PSD plot
4.3. DRO station Signal and PSD
Figure 17: Typical DRO Z channel helicorder plot
Figure 18: Typical DRO Z channel PSD plot
Figure 19: Typical DRO Y channel PSD plot
Figure 20: Typical DRO X channel PSD plot
Figure 21: UPATRAS GEObit stations
