An Advanced Dynamic Visualization Method of Global Ocean Tide with Multi-core Processor Based on OpenGL

In terms of ocean tide visualization, to meet the requirement of both display range and operational efficiency, an advanced method is proposed, in which the tide height is rapidly computed with global tide model EOT10a, and dynamically displayed by OpenGL. Aiming at the large amounts of calculation of global tide height, the feature of multicore processor is integrated into the method. The experiment shows that, compared to a single-core processor, when using a 6-core processor, the speedup ratio is about 5.4, parallel efficiency reaches 90%, and 880 000 tide heights can be calculated per second. Eventually, the result would be output as a tide height graph by OpenGL. This method could be a useful tool for marine cartography due to the large display range and the high efficiency.

First results of undersea muography with the Tokyo-Bay Seafloor Hyper-Kilometric Submarine Deep Detector

Tidal measurements are of great significance since they may provide us with essential data to apply towards protection of coastal communities and sea traffic. Currently, tide gauge stations and laser altimetry are commonly used for these measurements. On the other hand, muography sensors can be located underneath the seafloor inside an undersea tunnel where electric and telecommunication infrastructures are more readily available. In this work, the world’s first under-seafloor particle detector array called the Tokyo-bay Seafloor Hyper-Kilometric Submarine Deep Detector (TS-HKMSDD) was deployed underneath the Tokyo-Bay seafloor for conducting submarine muography. The resultant 80-day consecutive time-sequential muographic data were converted to the tidal levels based on the parameters determined from the first-day astronomical tide height (ATH) data. The standard deviation between ATH and muographic results for the rest of a 79-day measurement period was 12.85 cm. We anticipate that if the length of the TS-HKMSDD is extended from 100 m to a full-scale as large as 9.6 km to provide continuous tidal information along the tunnel, this muography application will become an established standard, demonstrating its effectiveness as practical tide monitor for this heavy traffic waterway in Tokyo and in other important sea traffic areas worldwide.

Fix Ballas Simulation to Achieve The Stability of The Shipyard Graving Dock Door

Indonesia’s geograpycal is archipelago. As archipelago, Indonesia has been recognized world by internationally. Srategic conditions in Indonesia demand that the county is able to develop the potential of the maritime. One of the efforts in develelopment about maritime potential is one of them is manufacture model dry dock gate is stable. Dry Dock Shipyard Door Modeling is used to carry out the analyzes needed by the research and also wants to promote the use according to the needs of the field, both in terms of safety, comfort and budget in terms of operational safety. This research program aims to resolve the stability of Dry Dock doors with a length of 40.4 meters using Maxsurf and Hydromax software in analyzing estimates using intervals of 500 mm in length expected to produce detailed data leading to longitudinal and transverse data as asked by the process ship planning in general. The result of dry dock gate analysis with a length of 40.4 m meets IMO standards where ballast construction requires 54% and 68% and using ballast fix will be able to produce a GMt value of 1.693 m with a tide height of 10.393 m. GMt values indicate the gate dick can remain stable and sturdy standing at the bottom of the dock when dry. when the ballast is empty, it will produce GMt 1,007, which means the dock is stable, but it is still easily broken down. These conditions govern when maintaining dry dock doors

Harbour seals responded differently to pulses of out-migrating coho and Chinook smolts

There is increasing evidence that predation by harbour seals on out-migrating salmon smolts may be responsible for the low return of adult coho and Chinook salmon in the Salish Sea. However, little attention has been given to understanding where and when this predation occurs and the extent to which it might be conducted by few or many seals in the population. We equipped 17 harbour seals with data loggers to track seal movements and used accelerometry to infer prey encounter events (PEEs) following the release of ~384000 coho (May 4, 2015) and ~3 million Chinook (May 14, 2015) smolts into the Big Qualicum River. We found a small proportion (5.7%) of all PEEs occurred in the estuary where salmon smolts entered the ocean—and that only one-quarter of the seals actively fed there. PEE counts increased in the estuary after both species of smolts were released. However, the response of the seals was less synchronous and occurred over a greater range of depths following the release of the smaller-bodied and more abundant Chinook smolts. Harbour seals feeding in the estuary appeared to target coho smolts at the beginning of May but appeared to pursue predators of Chinook smolts in mid-May. PEE counts in the estuary increased as tide height rose and were higher at dusk and night—especially during full moonlight. Such fine-scale behavioural information about harbour seals in relation to pulses of out-migrating smolts can be used to design mitigation strategies to reduce predation pressure by seals on salmon populations.

Behavioral aspects of waterbirds

Estuaries are used by waterbirds as foraging, resting and nesting sites, serving also as shelter for migratory birds. The dynamics of this avifauna in an aquatic environment may be associated with the differences of time of day, tide height, temperature, wind speed and use of the site by different species. This study had the objective of evaluating behavioral aspects of aquatic birds, relating the influence of environmental variables with their activities. Bird counts were performed at the mouth of two important rivers of the state of Santa Catarina, Brazil, during two-hour intervals throughout the day in monthly samplings between June (2015) and May (2016). A total of 44 species were recorded, ten of which were migratory. The most recorded behaviors were foraging and resting. The Kruskal-Wallis analysis indicated no significant difference in behavior between the sampling intervals. The Bray-Curtis similarity test resulted in three groups: 1) - species that foraged most of the time; 2) - species that rested most of the time; and 3) - same time in both activities. The Indicator Species Analysis showed that 17 species were associated with only one microhabitat and 15 species with more than one. The Canonical Correlation Analysis indicated that only tide height, temperature and rainfall variables were correlated with the behaviors performed and only the resting activity was positively correlated with all variables. This may be associated with thermoregulation and the ability of some species to stay in midlitoral at high tide. The results demonstrate that different waterbird species used the studied areas in different ways. Thus, the heterogeneity of microhabitats in an aquatic environment of extreme importance for the coexistence and maintenance of the diversity of waterbirds.

Determining the gravitational effects on tide height on an stuary and theoretical comparisons

Two identical homemade prototypes are used to monitoring the tide levels on two strategic points of the Serinhaém estuary. This monitoring was realized along a period close to the new moon phase. From the analysis of the experimental results, the average height of the tide is determined between each period of high-tide and low-tide. These estimations show discrepancies minors than half order of magnitude, compared to the theoretical predictions of the static and dynamic oceanic tide models. Also the amplification effects of the tide in the estuary head can be quantified exhibiting a maximum gain 1.33, which is observed in the new moon phase.