IASPEI - Picture Gallery

IUGG XXIV General Assembly July 2-13, 2007 Perugia, Italy
(S) - IASPEI - International Association of Seismology and Physics of the Earth's
Interior
JSS010 Poster presentation 2088
Analysis of thermal neutron ground observations in accordance with space
observations of seismo-electromagnetic phenomena
Dr. Ekaterina Sigaeva
Space Physics Research Department Skobeltsyn Institute of Nuclear Physics
Irina Myagkova, Ekaterina Muravieva, Yuri Kuzmin
Long-term ground-based observations have shown that thermal neutrons' flux is very sensitive
regarding different processes both in the near-Earth space and in the Earth's crust due to the dual
nature of the neutron flux near the Earth's surface. The first source of neutrons is bound up with the
high-energy particles of cosmic rays, which produce neutrons in the interactions with the elements of
the atmosphere. The second source originates from the natural radioactive gases of the Earth's crust.
The calculations have shown that the impact of the second source strongly depends on geographical
location of the observation point, i.e. on the local conditions of the gases' emission. Besides any change
of these conditions will result in variations of the thermal neutrons' flux. For instance, tidal wave's
influence on the Earth's crust leads to presence of harmonics in the thermal neutrons' observations,
which are well known from grvaity surveys.The recent observations of the thermal neutrons' flux in the
seismic-active area of Kamchatka resulted in a conclusion that the most part of the strong earthquakes
occured in the sufficiently broad area along the boundary of the Pacific and Euro-Asian tectonic plates
"produce" increased neutrons' flux at Kamchatka experimental unit. At the same time there are a lot of
local effects (including climate, weather, etc.) which also lead to changes of neutrons' flux. Therefore
it's very important to separate the variations of geodynamical nature from the rest in order to use them
as earrthquake precursors and to develop a new method of earthquake prediction.One of the possible
ways for such separation can be implemented by means of analysis of the neutrons' flux data and the
seismo-electromagnetic data obtained by space missions. In this paper the results of cross-section
analysis of the neutrons' data and the charged particles' precipitation under the Earth's radiation belts in
order to find the characteristics of geodynamic variations of the neturons' flux are presented.
Keywords: neutron, precursor, seismo electromagnetic