Geophysical Institute of the ASCR

It is thus possible to roughly estimate that about one third of the contemporary warming may have
its origin in the local environmental pollution (Čermák et al., 2004).
iv. The practical use of the “geothermal” inversion method is based on the assumption, that the heat
transfer in the subsurface is managed by the heat conduction, i.e. the temperature field is not
affected by local hydrogeological conditions. We have inverted T(z)-records from four closely
spaced boreholes at Tachlovice (15 km SW of Prague) when the heat conduction equation was
completed by an additional assumption of the existence of a horizontal water migration, the
measured temperature were then correlated with the theoretical response on the changing surface
(climate) condition simulated by the air temperature-time series from the Karolinum
meteorological station. It was possible then to estimate the so-called “pre-observational mean”
POM-temperature, the conditions existing before the registration had started (before year 1791) and
also the (Darcy) velocity of the hypothetical water movement. It could be proved that for a slightly
advectively disturbed case the difference between the POM-value for the pure conduction and
combined conduction/convection amounted to 0.3 – 0.5 K and approximatelly equaled to the
generally accepted warming for the 20th century based on the long-term meteorological records
(Bodri and Čermák, 2005).
References
Bodri L. and Čermák V., 2001. Neural network prediction of monthly precipitation: application to summer flood occurrence
in two reghions of Central Europe. Stud. Geophys. Geod., 45, 155-167.
Bodri L.and Čermák V., 2003a. High-frequency variability in recent climate and the North Atlantic Oscillation. Theoretical
and Applied Climatology, 74, 33-40.
Bodri L. and Čermák V., 2003b. Prediction of surface air temperature by neural network, examples based on three-year
temperature monitoring at Sporilov station. Stud. Geophys. Geod., 47, 173-184.
Čermák V. and Bodri L., 1999. Climate Change Inferred from Borehole Temperatures: Regional Pattern of Climatic Changes
in the Czech Republic. World Resource Review, 11, No.2, 220-228.
Čermák V., Šafanda J., Krešl M. and Dědeček P., 2004. Geotermika mapuje klimatické změny, Čas.čs.fyz., 54 (4), 244-246.
Bodri L. and Čermák V., 2005. Borehole temperatures , climate change and the pre-observational surface air temperature
mean: allowance for hydraulic conditions, Global Planet.Change, 45, 265-276.
Bodri L., Čermák V. and Krešl M., 2005. Trends in precipitation variability: Prague (The Czech Republic). Climatic Change,
67 (in print).
Šafanda J., Čermák V. and Bodri L., 1997. Climate history inferred from borehole temperatures, data from the Czech
Republic. Surveys in Geophysics, 18, 197-212.
Structural aspects of the evolution of volcanic centres: the České
středohoří Mts. as an example
Former geophysical surveys performed in the region of the volcanic centre of the České středohoří
Mts. in North Bohemia (the Ohře/Eger Rift zone) showed that anomalous volcanic bodies and features
can be effectively identified within a sedimentary environment. For this reason we carried out new
geophysical measurements in the area of the main mafic intrusion of essexitic character. The target
was the exact location and geometry of the intrusion and its relation to other components of the
volcanic centre.
We used gravity, magnetic, shallow seismic and electromagnetic techniques. The new gravity and
magnetic data were tied to the old databases so that we could investigate the area as a whole complex.
Residual gravity fields enhanced the image of trachytic breccia collapse structure to the north of the
intrusion and the impressive positive anomaly of the intrusion itself. As well, other volcanic bodies
were expressed in these maps and contributed to the volcanic sequences extent limitation.
Electromagnetic measurements were applied in the area of the expected extent of the intrusion, and
the seismic measurements in the central part of the intrusion.
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