Large volume air-gun sources and its seismic waveform characters
ZHAO Ming-Hui~1, QIU Xue-Lin~1, XIA Shao-Hong~1, WANG Ping~1, XU Hui-Long~1, YE Chun-Ming~2, KANG Ying~21 Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China 2 Earthquake Administration of Guangdong Province, Guangzhou 510070, China
The large volume air-gun sources have been successfully applied in onshore-offshore seismic experiments in northern South China Sea, and in a reservoir located in Hebei Province. The permanent stations can receive the seismic signals from the air-gun sources as far as 255 km away. The seismic waveform characters are easily identified comparing with the waveforms of natural earthquake and explosion of similar magnitude. The air-gun signals usually have 4～8 Hz dominant frequency, 3～5 wave peaks, ±0.15 μm·s ~ -1 amplitude, and distributed at regular time-intervals. And this kind of air-gun sources have many advantages, such as high energy, high repeatability of firing, high S/N ratio, and environmental protection. The above characters indicate that the new 1500 LL air-gun sources are very suitable for studying continental and oceanic crustal structures.