The hydroacoustic method for the quantification of the gas flux from a submersed bubble plume |
| |
| Authors: | S I Muyakshin E Sauter |
| |
| Institution: | (1) Department of Geological Sciences, University of California, Santa Barbara, CA 93106, USA;(2) Chemical Engineering Department, University of California, Santa Barbara, CA 93106, USA;(3) Department of Geography, University of California, Santa Barbara, CA 93106, USA |
| |
| Abstract: | This article presents an inverse hydroacoustic method for the remote quantification of the total gas flux transported from
an underwater bubble plume. The method includes the surveying of the bubble plume by a vertically looking echo sounder and
the calculation of the flux using the spatial distribution of the ultrasound backscattering at a fixed depth. A simplified
parameterization containing only a few parameters is introduced to describe the empirical bubble size distribution. The linear
correlation between the backscattering cross section of the bubble stream and the vertical gas flux is found. The calculation
procedure takes into account the occurrence of a gas hydrate film at the bubble’s surface. The influence of different parameters
on the accuracy of the method is investigated. The resolution volume of the echo sounder corresponding to the fixed distance
is considered as a two-dimensional spatial window. The method was applied to quantify the total convective methane flux at
the Haakon-Mosby mud volcano (HMMV) depth 1280 m. The calculated values of the total flux near the bottom (100–400 t/year)
are in good agreement with the independently estimated flux for the single bubble jet observed from the ROV (70 t/year). These
calculations also show significant temporal variability of the flux at the HMMV. The total flux was found to vary by about
a factor of 2–3 within time scales of days. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
