The feasibility of laser strainmeters for sea floor diagnostics

Supersensitive Detector of Hydrosphere Pressure Variations

“…The interval in recording these oscillations by the laser strainmeter and the detector of hydrosphere pressure variations is about 38 min 35 s. Detection of synchronous oscillations with such a delay indicates that the source of oscillations is in water and the signal has come through the Earth's crust to the laser strainmeter and through the water to the detector of hydrosphere pressure variations. In accordance with Dolgikh et al [24], we calculate the speed of a surface wave in deep water using the formula The processed record fragment began at 08 h 53 min 35 s and ended at 08 h 55 min 30 s on 3 June 2019. During processing of the synchronous record of the supersensitive detector of hydrosphere pressure variations, the presence of oscillations with characteristic periods, singled out from the laser strainmeter record, was established, but time-wise they were recorded much later than the oscillations singled out on the laser strainmeter.…”

“…The interval in recording these oscillations by the laser strainmeter and the detector of hydrosphere pressure variations is about 38 min 35 s. Detection of synchronous oscillations with such a delay indicates that the source of oscillations is in water and the signal has come through the Earth's crust to the laser strainmeter and through the water to the detector of hydrosphere pressure variations. In accordance with Dolgikh et al [24], we calculate the speed of a surface wave in deep water using the formula…”

“…From left to right: harmonic signal with a duration of 30 s, phase-shift keyed signal (M-sequence) with a duration of 30 s, phase-shift keyed signal (M-sequence) with a duration of 10 s, sweep signal with a duration of 10 s, two phase-shift keyed signal (M-sequence) with a duration of 15 s. In the summer of 2019, we researched the regularities of low-frequency hydroacoustic signals propagation from the open sea to a semi-closed bay through the land part of Shultz Cape. Generation of low-frequency harmonic signals was made using two hydroacoustic emitters of the electromagnetic type, operating at frequencies of 33 [24] and 22 Hz [25]. The detector of hydrosphere pressure variations was located inside the Vityaz Bay.…”

“…Generation of low-frequency harmonic signals was made using two hydroacoustic emitters of the electromagnetic type, operating at frequencies of 33 [24] and 22 Hz [25]. The detector of hydrosphere pressure variations was located inside the Vityaz Bay.…”

“…The developed and created supersensitive detector of hydrosphere pressure variations based on an equal-arm Michelson interferometer, which has unique amplitude-frequency characteristics, is designed In the summer of 2019, we researched the regularities of low-frequency hydroacoustic signals propagation from the open sea to a semi-closed bay through the land part of Shultz Cape. Generation of low-frequency harmonic signals was made using two hydroacoustic emitters of the electromagnetic type, operating at frequencies of 33 [24] and 22 Hz [25]. The detector of hydrosphere pressure variations was located inside the Vityaz Bay.…”