Effect of Space
Weather observed in the Czech oil pipeline network
Hejda, P. and Pek, J.
Institute of Geophysics of the CAS, Prague, Czech
Although the buried pipelines are provided
with an insulating coating, there are always points where the
insulation is defective and the pipeline is threatened by corrosion.
For this reason, the pipelines are equipped with a cathodic protection
system which keeps the pipeline at a negative potential of about 1 to
2 volts in relation to the ground. The pipe to soil voltage in the
Czech oil pipelines is checked and recorded at about 80 stations. As
the pipelines represent long electric conductors they respond to
electric fields induced by variations of the geomagnetic field.
Variation of the pipe to soil voltage does not represent a real threat
for the pipeline, as it is usually a short time effect. However the
data contain interesting information about geomagnetically induced
Data from autumn 2005 to 2017 were analyzed. The data were cleaned
from variations caused by local sources or by artificial effects. This
was done by comparison with data from neighboring stations. The
variation of the pipe to soil voltages was classified by several
characteristics and compared with planar model of the geoelectric
field computed from geomagnetic variation observed at the Budkov
Observatory. It was also possible to compare several events with data
obtained by magnetotelluric field measurements. It is shown that the
effect of weak magnetic disturbances is negligible as the cathodic
protection can compensate it promptly. On the other hand, the signal
of strong magnetic storms is quite pronounced. The statistics as well
as selected events are presented.