Measuring the sound speed in deep-sea first sediment layer using a high-frequency submersible sub-bottom profiler: Method and sea trial application

2021 ◽  
pp. 1-11
Author(s):  
Zhiguo Qu ◽  
Dapeng Zou ◽  
Mingguang Shan ◽  
Xinghui Cao ◽  
Yongqiang Xie
Keyword(s):  
Deep Sea ◽  
High Frequency ◽  
Sound Speed ◽  
Sediment Layer ◽  
Sea Trial

A Study of the Sealing Performance of a New High-Pressure Cone Valve for Deep-Sea Gas-Tight Water Samplers

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Shi-Jun Wu ◽  
Can-Jun Yang ◽  
Ying Chen ◽  
Yan-Qing Xie
Keyword(s):  
Finite Element Analysis ◽  
High Pressure ◽  
Deep Sea ◽  
Hydrothermal Fluid ◽  
Contact Model ◽  
Element Analysis ◽  
Sea Trial ◽  
Sealing Performance ◽  
Pressure Cone ◽  
Gas Tight

The cone valve plays an important role in high-pressure sealing applications. In this paper, a new high-pressure cone valve, based on the titanium alloy poppet-to-polyetheretherketone seat sealing structure, is proposed for deep-sea gas-tight water samplers. In order to study the sealing performance of the new valve, both the conforming poppet-seat contact model and the nonconforming poppet-seat contact model were evaluated. Finite element analysis based on the two models was performed and validated by experiments. The results indicate that the nonconforming poppet-seat contact model has a better sealing performance than the conforming poppet-seat contact model. The new cone valve also was applied in a gas-tight hydrothermal fluid sampler and successfully tested in a sea trial during the KNOX18RR cruise from 9 July to 12 August 2008.

Depth Profiling Investigation of Seawater Using Combined Multi-Optical Spectrometry

2020 ◽  
Vol 74 (5) ◽  
pp. 563-570 ◽  
Author(s):  
Wangquan Ye ◽  
Jinjia Guo ◽  
Nan Li ◽  
Fujun Qi ◽  
Kai Cheng ◽  
...  
Keyword(s):  
Deep Sea ◽  
Depth Profiling ◽  
Deep Ocean ◽  
Euphotic Zone ◽  
Depth Resolution ◽  
Remotely Operated Vehicle ◽  
Sea Trial ◽  
Depth Profiles ◽  
Diving Depth ◽  
Optical Spectrometry

Depth profiling investigation plays an important role in studying the dynamic processes of the ocean. In this paper, a newly developed hyphenated underwater system based on multi-optical spectrometry is introduced and used to measure seawater spectra at different depths with the aid of a remotely operated vehicle (ROV). The hyphenated system consists of two independent compact deep-sea spectral instruments, a deep ocean compact autonomous Raman spectrometer and a compact underwater laser-induced breakdown spectroscopy system for sea applications (LIBSea). The former was used to take both Raman scattering and fluorescence of seawater, and the LIBS signal could be recorded with the LIBSea. The first sea trial of the developed system was taken place in the Bismarck Sea, Papua New Guinea, in June 2015. Over 4000 multi-optical spectra had been captured up to the diving depth about 1800 m at maximum. The depth profiles of some ocean parameters were extracted from the captured joint Raman–fluorescence and LIBS spectra with a depth resolution of 1 m. The concentrations of [Formula: see text] and the water temperatures were measured using Raman spectra. The fluorescence intensities from both colored dissolved organic matter (CDOM) and chlorophyll were found to be varied in the euphotic zone. With LIBS spectra, the depth profiles of metallic elements were also obtained. The normalized intensity of atomic line Ca(I) extracted from LIBS spectra raised around the depth of 1600 m, similar to the depth profile of CDOM. This phenomenon might be caused by the nonbuoyant hydrothermal plumes. It is worth mentioning that this is the first time Raman and LIBS spectroscopy have been applied simultaneously to the deep-sea in situ investigations.

A Pressure-Tight Sampler with Flexible Titanium Bag for Deep-Sea Hydrothermal Fluid Samples

2020 ◽  
Vol 37 (11) ◽  
pp. 2065-2073
Author(s):  
Xun Wang ◽  
Shi-Jun Wu ◽  
Zhen-Fang Fang ◽  
Can-Jun Yang ◽  
Shuo Wang
Keyword(s):  
Organic Carbon ◽  
Deep Sea ◽  
Hydrothermal Vents ◽  
Hydrothermal Fluid ◽  
Titanium Foil ◽  
Fluid Sample ◽  
Sea Trial ◽  
Diaphragm Valve ◽  
Metal Seal

AbstractThis paper details the development and application of a novel pressure-tight sampler with a metal seal capable of acquiring high-purity fluid samples from deep-sea hydrothermal vents. The sampler has a titanium diaphragm valve for sampling and a flexible titanium foil bag to store the fluid sample. Hence, all parts of the sampler in contact with the sample are made of titanium without elastomer O-ring seals to minimize the organic carbon blank of the sampler, which makes it suitable for collecting organic samples. A pressure-tight structure was specially designed to maintain the sample at in situ pressure during the recovery of the sampler. The sampler has been successfully tested in a sea trial from November 2018 to March 2019, and pressure-tight hydrothermal fluid samples have been collected.

Sea Trial Results of ROV “ABISMO” for Deep Sea Inspection and Sampling

2008 ◽  
Author(s):  
Tomoya Inoue ◽  
Hiroyuki Osawa ◽  
Hiroshi Yoshida ◽  
Junichiro Tahara ◽  
Shojiro Ishibashi ◽  
...  
Keyword(s):  
Water Depth ◽  
Deep Sea ◽  
Earth Science ◽  
Sagami Bay ◽  
Sampling System ◽  
Sediment Samples ◽  
Sea Trial ◽  
The Third ◽  
Onboard Equipment ◽  
Water Depths

JAMSTEC (Japan Agency for Marine-Earth Science and Technology) has been developing the deep sea ROV ABISMO (Automatic Bottom Inspection and Sampling Mobile) having the capability to dive to the deepest sea. The purposes of ABISMO are to inspect on the seabed in the deep sea and to obtain sediment samples from there. ABISMO consists of a launcher and a vehicle which is launched from the launcher and surveys on the seabed to determine the place for sampling. Core sampling system, which is exchangeable with a gravity piston type or a grab type, is equipped in the launcher. The both of the launcher and the vehicle have cameras to observe. One of the features of ABISMO is that the vehicle has crawlers in addition to thrusters in order to advance mobility. ABISMO is operated with the support ship KAIREI and dived by means of its onboard equipment including a primary cable. We conducted sea trials in January and September 2007 at the areas with the water depths up to 1,300m in Sagami Bay as primary function tests. And we conducted the third sea trial at Izu-Ogasawara trench in December 2007 and made the successful results of diving to the depths up to 9707 m and obtaining a sediment sample from the seabed in 9760 m water depth. This paper describes the features and the outline of ABISMO as well as the sea trial results.

Study of the Sealing Characteristic of Polytetrafluoroethylene-Coated O-Ring Applied in Gas-Tight Deep-Sea Water Sampler

2011 ◽  
Vol 295-297 ◽  
pp. 3-10 ◽  
Author(s):  
Hao Cai Huang ◽  
Yan Ying Ye ◽  
Can Jun Yang ◽  
Jian Xing Leng ◽  
Ying Chen
Keyword(s):  
Deep Sea ◽  
Sea Water ◽  
Theory And Practice ◽  
Gas Content ◽  
Element Analysis ◽  
Sea Trial ◽  
Deep Sea Water ◽  
Ocean Science ◽  
Water Sampler ◽  
Gas Tight

In ocean science research, it often requires the integrity of the gas content in samples of seawater. The gas-tight deep-sea water sampler (GTWS) based on pressure self-adaptive equalizer (PSAE) can satisfy the requirement very well. The PSAE is required to achieve a reliable dynamic sealing in deep sea. The general O-ring is difficult to meet this requirement. The polytetrafluoroethylene (PTFE)-coated O-ring is chosen as the sealing parts. The finite element analysis (FEA) software ANSYS is used to analyze the contact pressure of the PTFE-coated O-ring in different conditions, that is, analyze the GTWS’s gas tightness theoretically. Combine with the sea trial results, the feasibility and reliability of the PTFE-coated O-ring in deep-sea dynamic sealing in PSAE can be prove both in theory and practice.

SURFACE-GENERATED NOISE IN AN OCEAN WAVEGUIDE WITH A TRANSITION LAYER OF CONTINUOUSLY VARYING DENSITY AND SOUND SPEED

1999 ◽  
Vol 07 (04) ◽  
pp. 253-268 ◽  
Author(s):  
JIN-YUAN LIU ◽  
CHEN-FEN HUANG
Keyword(s):  
Continuous Spectrum ◽  
Sound Speed ◽  
Noise Intensity ◽  
Normal Modes ◽  
Vertical Direction ◽  
Sediment Layer ◽  
Noise Generation ◽  
Oceanic Waveguide ◽  
Noise Sources ◽  
Noise Field

This paper considers the noise field generated by surface random processes in an oceanic environment with a sediment layer possessing a continuously varying density and sound-speed profile. This model closely resembles the oceanic waveguide environment and therefore enables the simulation of surface noise generation. Many results of the noise field were generated, including the noise intensity distribution, vertical and horizontal correlations. It is demonstrated that the noise intensity may be affected by the stratification mainly through the continuous spectrum, in that the continuous spectrum is equally important as the normal modes in the present analysis. Moreover, the results for the correlations show that the noise field in the horizontal direction becomes more coherent when the noise sources are more correlated, while in the vertical direction, the results tend to reverse. The horizontal correlations of the noise field due to surface random sources with nonisotropic power spectrum, such as nonisotropic Gaussian and Pierson–Moskowitz, were generated and analyzed.

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