Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The near surface vertical atmospheric electric field abnormality could
  be as a promising imminent precursor of major earthquakes   A promising short term precursor of major earthquakes (EQ) is very crucial in
saving people and preventing huge losses. Ez, atmospheric electrostatic field
vertical component, under fair air conditions, is generally oriented downwards
(positive). Anomalous negative Ez signals could be used as an indicator of a
great number of radioactive gases which are released from great number of rock
clefts just before major earthquakes. Enhanced emission of radon radioactive
decay will produce an anomalously large number of ion pairs. The positive
particles will be transported downward by the fair weather electrostatic field
and pile up near the surface. Finally, obviously and abnormally, an oriented
upward atmospheric electric field Ez near the ground could be formed.
Therefore, monitoring this Ez may be applied effectively in earthquake warning.

26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio