1998/11/01 by Hiroshi Matsumoto, Motoji Ikeya, C. Yamanaka · 2 citations
Earth and Planetary Sciences · Engineering · #Earthquake Detection and Analysis #Seismic Waves and Analysis #Geophysical Methods and Applications #Van de Graaff generator #Fault (geology) #Geology #Noise (video) #Seismology #Quartz #Microwave #Acoustics #San andreas fault #Optics #Physics
paper · doi:10.1143/jjap.37.l1409
openalex publication_date 1998/11/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
Barber-pole color shift and speckle noise in the images on the videotape of a TV program recorded six and a half hours before the Kobe earthquake have been analyzed and are considered to be due to electromagnetic (EM) noise of a few tens of mV/m around 217 MHz and pulsed noise with a width of about µs, respectively. Such images were reproduced by artificial means using a microwave synthesizer and from air-gap discharges using a Van de Graaff generator. An EM model of a fault with piezo-compensating free charges around quartz in granitic rocks gave pulsed EM waves having a pulse width of 0.5 µs and height of 0.5 V/m at a point 50 km from the fault.