# Seismic Observations in Bucharest Area with a Raspberry Shake Citizen Science Network
## 2 Bucharest Raspberry Shake Seismic Network  
The Raspberry Shake is a plug-and-go solution for seismological applications. It can record earthquakes from very small magnitudes that are not felt by humans to destructive earthquakes that occur in many places on Earth. This seismometer, with similar characteristics to professional ones, but with much lower production and maintenance costs, is produced in a wide variety of setups: 1D, 3D, 4D, Boom, and Shake&Boom. Due to the widespread installation of these RSs, the Raspberry Shake Citizen Science Network currently lists over 2000 online seismometers and their number is continuously increasing [11]. RS4D is a seismograph equipped with multiple sensors (Figure 1). RS4D includes a Raspberry Pi computer, a vertical geophone (4.5 Hz and sampling rates are adaptable up to 100 Hz), a triaxial accelerometer, a digitizer, and near-real-time miniSEED data transmission. The performance of RS4D in the context of seismic wave propagation monitoring was evaluated by laboratory tests and field observations by [20]. During the investigated period, no significant earthquakes occurred in the Vrancea region and therefore no data from accelerometers were used [21]. Unlike RS4D, RS1D (Figure 1) contains a Raspberry Pi computer, a vertical geophone, a digitizer, and near-real-time miniSEED data transmission. Moreover, also in [22], it was observed that RSs are more suitable for characterizing local events with magnitude M > 2.5, regional events with magnitude M > 4.5, or teleseismic events with magnitude M > 6. However, given their easy installation, relatively low cost, and real-time data transmission, RS sensors may be an ideal candidate for the densification of seismic networks for local and regional events whose data can be used in both public information programs and research studies. The power supply is 5 V (2.5 A) and the power consumption for an RS unit is estimated at 2.8 W at start-up and 1.5 W during operation. Data are stored on a local SD card (default 8 Gb, but larger cards can be installed). The estimated amount of data per channel is less than 10 Mb per day. The local storage can thus be adapted according to the SD card fitted, the number of sensors, and the selected sampling rate. Time synchronization is based on NTP (Network Time Protocol), but a GPS module can be connected via USB. The Raspberry Pi computer is pre-programmed and contains the SeisComP3 software [23]. SeisComP is a  
Figure 1: (**a**) Raspberry Shake 4D sensor (vertical geophone, triaxial accelerometer and digitizer) and (**b**) Raspberry Shake 1D sensor (vertical geophone and digitizer). seismological software for interactive data acquisition, processing, distribution, and analysis. It includes many features based on standard protocols (e.g., seedling) and allows data acquisition, waveform distribution and archiving, and real-time data exchange archiving. Waveforms are saved in miniSEED format. Using the SeisComP software package, data from seismometers are accessed via FDSN (International Federation of Digital Seismograph Networks [24]) web services. A data-flow transmission scheme is presented in Figure 2.  
From the Raspberry Shake FDSN web services, the data is downloaded with Python notebooks from JupyterHub. The notebooks are based on the ObsPy Python module, which is a collection of open-source programs developed to provide a Python framework for the acquisition/processing and analysis of seismological data [25; 26; 27]. For amateurs, there is the possibility to view the data in the manufacturer's apps on both internet-connected devices [28] and smartphones [29]. Earthquake citizen science networks can significantly contribute to mitigating seismic risk and improving citizens' knowledge of seismology and earthquakes [30; 31; 32] in areas with intense seismic activity or that are affected by the seismic activity in the surrounding areas.