Estimation of sea surface temperature (SST) using marine seismic data
DRS at CSIR-National Institute of Oceanography
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Title |
Estimation of sea surface temperature (SST) using marine seismic data
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Creator |
Sinha, S.K.
Dewangan, P. Sain, K. |
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Subject |
METEOROLOGY AND CLIMATOLOGY
METEOROLOGY AND CLIMATOLOGY GEOLOGY AND GEOPHYSICS OCEANOGRAPHY AND LIMNOLOGY OCEANOGRAPHY AND LIMNOLOGY |
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Description |
Not much attention is given to direct wave arrivals in marine seismic data that are acquired for petroleum exploration and prospecting. These direct arrivals are usually muted out in routine seismic data processing. In the present study, we process these direct arrivals to accurately estimate soundspeed in near-surface seawater and invert for sea surface temperature. The established empirical equation describing the relationships among temperature, salinity, pressure and soundspeed is used for the inversion. We also discuss processing techniques, such as first-break picking and cross-correlation for the estimation of soundspeed, that are well known among petroleum-industry geophysicists. The accuracy of the methods is directly linked to the data quality and signal processing. The novelty in our approach is in the data conditioning, which consists essentially of spectral balancing based on a wavelet transform that compensates for spherical spreading and increases the signal-to-noise (S/N) ratio. The 2D seismic data used in this paper are from the offshore Krishna-Godavari Basin east of India. We observe a significantly higher soundspeed of 1545 m/s for near-surface water than the commonly used value of ~1500 m/s. The estimated temperature (from velocity) is about 30 °C. Interestingly, the estimated temperature matches well with the temperature recorded in the CTD profile acquired in the study area during the month of May, the month corresponding to the acquisition of seismic data. Furthermore, the estimated temperatures during different times of data acquisition correlate well with the expected diurnal variation in temperature
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Date |
2016-05-12T12:43:54Z
2016-05-12T12:43:54Z 2016 |
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Type |
Journal Article
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Identifier |
Pure and Applied Geophysics, vol.173(4); 2016; 1305-1316
http://drs.nio.org/drs/handle/2264/4969 |
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Language |
en
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Rights |
An edited version of this paper was published by Springer. This paper is for R & D purpose and Copyright [2015] Springer
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Publisher |
Springer
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