Yutaka Yasui, a Japanese seismologist for Kakioka Magnetic Observatory made his personal observations and documented 34 detailed accounts of EQL including 14 sketches and 10 photographs taken by residents in the Matashiro area. Later, Yasui concluded that 18 of the 34 detailed accounts could not be elucidate by known lighting activity like twilight, zodiacal light, auroras, meteors and other sources and the other 16 accounts cannot be considered natural phenomena (Wagner, 1978).
The appearances of these strange lights during and after an earthquake are also visible in other parts of the globe. In 1976, a stunning EQL activity covering several hundred of square kilometers was seen in mainland China. Many other recorded sightings in various parts of the world including Hawaii, Taiwan, Alaska, Soviet Union, and the United States.
Earthquake Lights or EQL are generally known as bright luminescence based near ground level or broad sky glows that cover areas up to several square kilometers and sometimes more (Wagner, 1978). EQL varies in color from bright white and blues to reds and oranges, occurrence with other colors than those mentioned said to be effects of variations in the atmosphere such as humidity, barometric pressure, pollutants and cloud cover (Wagner, 1978).
According to Wagner's (1978) article, a more detailed description of EQL summarized by two seismologists Yutaka Yasui and John Derr as:
a) Flashes of lights lasting from 10 seconds to 10 minutes.
b) Extensive blaze like search light beams limited to point sources. The estimated luminescent spheres are between 50-100cm in diameter up to 200m in diameter.
c) Incidences of EOL are mostly near areas of known active faulting, mountain peaks, and areas with rich deposit of high normative quarts or silicia minerals.
d) Usually occurring accompanied by major weather fronts instantaneous with earthquake activity.
e) Large decrease in electric potential gradient, radio interference ranging from 10-20KHZ, absence of anomalies in magnetometer and spectroscope readings during EQL activity.
f) Presence of atmospheric potential gradients and increase in radon gas near mountain peaks and fault zones.
The most widespread explanation of EQL's mechanism is the violent low-level air oscillation due to tremor movement that sets up electrical disparity in the air. The other is the piezoelectric effects that occur when SiO2 rich rocks undergo stress. The theory is a less accepted because of the facts that EOL's are sighted and visible before the earthquake take place.
According to Wagner 1978, another weak theory is the explanation that some earthquake radiance is auroras (northern lights). Auroras are made up of charged particles about 60 miles above the earth and comes naturally in colors of blue and green. Auroras occur year round and most visible in fall and spring months and typically last an hour. Earthquake lights are only visible whenever there is a tremor and last for a few minutes.
There is a great possibility that EQL's are spawn by electrostatic charges considering animal behavior when an earthquake is about to take place (Wagner, 1978).