Deadline 9 June 2019
Organisation: Royal Observatory of Belgium
The Seismology-Gravimetry section of the Royal Observatory of Belgium (ROB) is looking for an early career and dynamic collaborator for the seismological branch of the BELSPO EPOS-BE project. This 2-year position is open at the post-doctoral level, but candidates who can prove enough knowledge on the following are still eligible (e.g. Engineering studies).
The ROB’s existing seismic and accelerometric observation infrastructure must be included in EPOS in order for the international seismological research community to get open access to research-proof seismic waveform data from the BE network. The BELSPO EPOS-BE project targets to:
- Replace short-period seismic stations by the installation of newly acquired broadband equipment at key locations in Belgium;
- Perform a full site characterization of selected seismic stations of the Belgian seismic network, with a priority on the broadband and accelerometric stations.
The candidate will be responsible for the site characterisation of network stations, hereby helped by the permanent researchers and technicians of the section. Tasks to perform for each site can be summarised as:
- Compiling all available data (geology, geomorphology, topography, geotechnical information, soil classes, etc.)
- Conducting field surveys to measure:
- H/V spectral ratios (HVSR)
- Recording surface waves using passive seismic array techniques
- If needed, complemented with active seismic profiling, electrical resistivity tomography or other non-invasive geophysical methods.
- Computing key parameters:
- Wavefield polarization
- Resonance frequency
- Rayleigh ellipticity
- A site’s Love and Rayleigh dispersion curve
- Shear-wave velocity (VS) profile
- Producing information sheets on network stations including:
- 1D velocity models obtained through dispersion curve inversion
- Vs30 and bedrock Vs
- Frequency dependent polarizations, evaluating the influence of topographical or local geological effects
As final product, an evaluation of site conditions using earthquake data needs to be performed which are needed to better correct instrumental records and to select appropriate GMPEs. This task will be performed in collaboration with the scientific staff of the section. The obtained site characterisation sheets will be implemented in European databases (e.g. SERAseismology, ORFEUS).
To meet the EPOS-BE site characterisation goals, the candidate must:
- Be independent, motivated, and capable to lead field surveys with colleagues and technicians
- Have strong field experience using the aforementioned survey techniques with emphasis on seismic array techniques
- Have an extensive knowledge of the processing, inversion and interpretation of HVSR and seismic array data, using the Geopsy software or equivalent
- Demonstrate proficiency in producing scientific reports and respecting deadlines
- Hold a driving licence (B)
- Show knowledge of or be ready to learn basic French and/or Dutch
- Proficiency in Python and Obspy.