Since the 1930s, the study of seismic luminescence
has entered a comprehensive development stage. People
no longer doubt about the real existence of earthshine,
and theoretical hypotheses explaining this phenomenon
have emerged. Japan led the way in these studies.
After 1965, Japanese scholars Yasui, Goro Kondo, Heng
Kuribayashi and others used geomagnetometer and rotary
collector for observation and research and took the first
photo of earthshine. In 1974, Chinese scholar Ma Zongjin,
after studying the macroscopic phenomena of previous large
earthquakes since the Xingtai earthquake, put forward that
earthshine is not only the result of the derivation of
earthquake but should be regarded as the unified process
of joint development of impending earthquakes. That is to
say, the earthshine and other phenomenon occurring at the
same time should be related and taken into consideration together.
The Hypothesis and Theory of Seismic Luminescence
In 1972, Japanese scholar Yasui and others proposed the view
of "low-level atmospheric oscillation". They argued that the
earth is weakly conductive because of the presence of various
positive and negative ions in the atmosphere. When gas molecules
in the atmosphere are hit by cosmic rays from space and radiation
from the earth's own radioactive elements, these ions are charged.
Radon is a major component of the radioactive materials in
earthquake zones, which are shaken into the atmosphere by
crustal vibration. Especially in the neutral and acidic rock
distribution areas with lots of radioactive materials and near
faultage, the content of radon in the atmosphere will be
significantly increased, which will also enhance the ionic
conductivity of the atmosphere.
If there is a natural electric field on the ground, there will
be a large discharge into the air will cause the ground to glow.
This kind of theory is the hypothesis that comparatively is the
case at present.
On February 4, 1975, there was an earthquake of 7.3 magnitude in
Haicheng and Yingkou, from Xiuyan in the east to Mian county in
the west, Liaozhong in the north and Xinjin in the south. Others
saw blue and white light directly from cracks in the ground
and pink fireballs coming out of the nozzle of the ground.