A variety of cameras have been, and presently are, mounted on remotely-operated vehicles (ROVs) owned by JAMSTEC. Usages of this video data is varied ― from front-mounted cameras for research and research-related observations, to rear-mounted cameras for checking for tether cable entanglement, and pen cameras to check sample canister contents or dial readouts. For biological research it is mostly the high definition video camera data that is used for studies where species identifications are a prerequisite. In 2012, “Ultra High Definition television” was presented as a new digital video format. The most popular format at present is what is termed “4K”, which has a resolution four times that of regular HD resolution. These movies are not only beautiful but reduce the need for zooming to identify organisms and thereby allow a stable, wider field of view for in situ field investigations. Therefore, 4K technologies are slowly being introduced into the arsenal of ROV-mounted cameras. In particular, one camera capable of capturing video at 4K resolution, the “GoPro” camera, is cheaper than almost all other 4K-capable cameras and has begun to be used widely experimentally. The large file sizes of ultra-high definition video files presents something of a problem concerning how the movie files can be best managed, archived and used. With the arrival of the “era of ultra-high resolution video” at our doorstep, we have to explore different integration techniques and analyze their advantages and disadvantages, particularly with the dual perspective of “how to take advantage of ultra-high definition video resolution” and “dealing with legacy video data”. Consequently, we have developed a method to integrate multiple video camera streams synchronously and output them as a single 4K video file. For this pilot study, video collected by the uROV PICASSO during a dive on November 13, 2013, was used. Video generated by the broadcast quality HDTV camera, two GoPro HERO 3⁺ cameras, and three NTSC “standard definition” cameras, as well as video captured from PICASSO's Logging System computer were captured and converted to .mov files. These were edited in Quicktime Player Pro and output as 4K video files with embedded timecode. In this paper, we discuss the full scope of the method development, as well as a protocol for naming video and video frame capture files. A step-by-step manual for the methodology is attached as an appendix.

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We developed a post-processing diagnostics package for output from regional weather or climate research models. The output data size of high-resolution models, even for regional studies, is considerably large due to the model complexity and integration of additional elements according to advances in computer technology. Therefore, the large amount of effort and time required for handling and analyzing such data seem to hinder the use of a high-resolution model for obtaining available and more detailed information. This diagnostics package supports and reduces workloads simultaneously performing necessary routine processing for analysis, comparisons to observations, and drawing figures, as seen in a web browser. The package was built for data analysis of long-term simulation outputs of the Altai Mountains area by using a regional climate model, the Weather Research and Forecasting (WRF) model.

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Laboratory experiment of electrical resistivity measurement using an alternative current (AC) impedance method is important to interpret the electrical survey and logging data, and to understand the electrical properties of rocks and sediments. This study investigated the accuracy and applicability of the AC impedance method by measuring resistors of known resistance (Experiment 1), electrolyte solutions of known resistivity (Experiment 2), and rocks and deep-sea core samples (Experiment 3). We confirmed that the accuracy of the measurement system was the same as that provided by manufacture in the Experiment 1. Two-electrode method was used for the Experiment 2, and the results showed that resistivity and phase angle increased with lowering of frequency and decreasing of the sample resistivity. The resistivity data was more accurate when the phase angle was close to zero. In the Experiment 3, we examined the way to prevent overestimation and underestimation of resistivity by drying and wetting of the sample surface, respectively, and wrapping a sample with parafilm was the most effective. In addition, we measured the samples of various porosity using two- and four-electrode methods. Four-electrode method had an advantage that is applicable to wide range of frequency (10² to 10⁵ Hz) because of its less influence of electrode polarization at low frequency, but reliable data ware also obtained using two-electrode method by measuring highly resistive samples or measuring with high frequency. Our data showed both two- and four-electrode methods were applicable to samples of various porosity (0.3 to 67％).

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We report in detail deep-sea sediments around the Japan Trench. We have collected core samples using a piston corer system and a MBARI type corer during the cruises KH-05-3 and KH-07-3 by R/V Hakuho-maru and KR04-08, KR08-10, KR09-16 and KR10-12 by R/V Kairei of Japan Agency for Marine-Earth Science and Technology. We recovered totally sixteen piston core samples and two MBARI type core samples in these cruises before the 2011 Tohoku earthquake. Fourteen coring sites are located on the outer rise on the Pacific plate, and 4 sites are on the landward trench slope. The core sediments are predominantly composed of diatomaceous silty clay interbedded with volcanic ash layers. Physical and magnetic properties of the core sediments, and lithological characteristics of tephras such as the refractive indices of volcanic glass and phenocrysts are reported as well.

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Increasing anthropogenic CO₂ in the atmosphere causes global warming and subsequent environmental changes, which may lead to an increase in natural disasters jeopardizing human society. Prompt technological development for CO₂ capture and sequestration is required in the international community. In this study, we performed CO₂ emission and shallow-type methane hydrate decomposition experiments at the Joetsu Knoll, offshore Joetsu, Niigata, Japan, as pilot studies to test feasibility of CO₂ sequestration and methane recovery using methane-CO₂ replacement in shallow-type methane hydrates. An isobaric cylinder pump and probe with a built-in heater (“Heat sonde”) were developed to inject CO₂ in deep-sea, high-pressure conditions. Before injecting CO₂ into a methane hydrate located in deep-sea sediments, we attempted CO₂ emission directly into deep-seafloor. In the experiment, liquid CO₂ was emitted at the head of Heat sonde, however, the isobaric cylinder pump became clogged during operation. The result reveals that precipitates of CO₂ hydrate, which are generated during mixing of inflow seawater and outflow liquid CO₂, blocked flow lines of the isobaric cylinder pump and Heat sonde. This suggests that our developed instruments must be improved for future work. We also observed the collapse of an exposed methane hydrate layer at the seafloor upon contact with the Heat sonde in our experiment.

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