EGU21-12312
https://doi.org/10.5194/egusphere-egu21-12312
EGU General Assembly 2021
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Geophysical study of viability for a new geomagnetic observatory at São Marcos (Portugal)

M. Alexandra Pais1,2, Paulo Ribeiro2, Katia Pinheiro3, Marcos Vinicius3, and Juergen Matzka4
M. Alexandra Pais et al.
  • 1University of Coimbra, CITEUC, Physics Department, Coimbra, Portugal (pais@fis.uc.pt)
  • 2University of Coimbra, CITEUC, Geophysical and Astronomical Observatory, Coimbra, Portugal
  • 3Department of Geophysics, Observatório Nacional, Rio de Janeiro, Brazil
  • 4GFZ German Research Centre for Geosciences, Potsdam, Germany

The magnetic observatory of Coimbra (IAGA code COI) measures the geomagnetic field components since 1866. These long time series were disturbed by the urban expansion in Coimbra city, causing anthropogenic perturbations in particular to the high frequency spectral band of the vertical Z component.

We plan to move the observatory to another site with less magnetic disturbances. The new site is about 15 km west of Coimbra over limestone Cretaceous terrains, in São Marcos (SMC). It is far from important industrial facilities, high voltage lines, and DC electrified railways. This farm is under administration of the University of Coimbra and is surrounded by walls.  

Both magnetic surveys and electrical soundings were carried out at SMC. Results show low values for the magnetic gradients and resistivity profiles of relatively low to moderate values (~ 10-1000 ohm.m), typical of the studied lithological types (sandstone, marl and limestone). In this study we characterize the geomagnetic field as measured at SMC, in comparison with COI and SPT (San Pablo/Toledo) in Spain, the nearest observatory in the INTERMAGNET network of magnetic observatories.

How to cite: Pais, M. A., Ribeiro, P., Pinheiro, K., Vinicius, M., and Matzka, J.: Geophysical study of viability for a new geomagnetic observatory at São Marcos (Portugal), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12312, https://doi.org/10.5194/egusphere-egu21-12312, 2021.

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