The effects of bottom sediments on the measured spectrum of seismic airgun pulses as a function of range

Abstract

Sound from seismic airgun pulses is well known to be a measurable component of the marine soundscape even hundreds of kilometers from the source vessel. The peak frequency of the pulses is normally below 100 Hz, and hence the concern is often raised that the airguns may mask the communications of large baleen whales. Recently, there have been reports of significant energy from seismic airguns in the range of 1–10 kHz which could mask calls from a wider range of marine life. Measurements and modeling of a variety of deep water environments are compared to show that environments with very hard bottom types support the long-range propagation of frequencies above 500 Hz from seismic airgun arrays.

The automation control system of intelligent flexible clearing robot

“…The working principle of the air cleaner is that the compressed air in the container, due to the reversing effect of the solenoid valve, the airflow is ejected instantly and at high speed, which directly acts on the material to cause it to spread or collapse. 1,2 This operation can be manual control or automatic control, which is quite easy to use. There are many types of shakers, the most widely used of which are electric shakers.…”