Archive for 02/02/2012

Hydro International – 

A first order for a Dynamic Positioning Inertial Navigation System (DP-INS) on a drillship has been received by Sonardyne International.

Vantage Drilling’s new 12,000 feet-rated drillship, Dragonquest, is set to become the first deep water drilling unit in the world to be equipped with the new system when it begins operations in the Gulf of Mexico for Petrobras later this year.

Sonardyne DP-INS aids vessel positioning through the integration of acoustic and inertial technologies and has been developed to meet regulatory requirements which state that deep water drilling units must be equipped with three independent position reference inputs to their DP system.

Traditionally, an acoustic positioning system and two separate DGPS systems are used. However, a vulnerability remains should the acoustics be affected by aeration and noise and both GPS systems be simultaneously affected by signal disruption.

The latter is particularly common around equatorial regions and during periods of high solar radiation. Solar activity is currently increasing and is forecasted by NASA to peak in 2013.

Consequently, there is a recognised need amongst operators for a third, independent DP reference that would allow safe rejection of a positioning error in one of the other two reference types DP-INS combines the complementary characteristics of Sonardyne’s Long and Ultra-Short BaseLine (LUSBL) positioning technology, with high integrity inertial measurements from its Lodestar AHRS/INS platform.

The resulting output is resilient to short-term acoustic disruptions and completely independent from GPS.

Full story…

 

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Hydro International – 

Oceanographers have identified a series of ocean ‘hotspots’ around the world. Strengthening wind systems have driven a number of oceanic currents, including the East Australian Current, polewards beyond their known boundaries.

The hotspots have formed alongside ocean currents that wash the east coast of the major continents, and their warming is proceeding at a rate far exceeding the average rate of ocean surface warming, according to an international science team, whose work is published in the journal Nature Climate Change.

Paper co-author, CSIRO’s Dr Wenju Cai, said that while the finding has local ecological implications in the region surrounding the hotspots, the major influence is upon the ocean’s ability to take up heat and carbon from the atmosphere.

In Australia’s case, scientists report intensifying east-west winds at high latitudes (45º-55ºS) pushing southward and speeding up the gyre or swirl of currents circulating in the South Pacific, extending from South America to the Australian coast.

The resulting changes in ocean circulation patterns have pushed the East Australian Current around 350 kilometres further south, with temperatures east of Tasmania as much as two degrees warmer than they were 60 years ago.

CSIRO’s climate scientist at CSIRO’s Wealth from Oceans Research Flagship Dr Wenju Cai said that detecting these changes has been hindered by limited observations but with a combination of multi-national ocean watch systems and computer simulations CSRIO have been able to reconstruct an ocean history in which warming over the past century is 2-3 times faster than the global average ocean warming rate.

Full story…

 

Hydro international –

Fugro Subsea Services is a manufacturer and operator of ROVs and provider of subsea engineering, construction support and inspection, maintenance and repair services.

Its Robotic Technologies business line has announced the introduction of three-dimensional sea current profiles to its DeepWorks family of subsea simulators.

Users can model currents as they vary with depth and location, enabling more realistic representations of current flows across large sea areas, in shallow waters and around targets.

Complex current profiles can be quickly configured to better understand the physical effects on objects like the ROV tether as it moves through different current fields.

An user-interface allows the operator to define the strength, heading and elevation of currents, at different geographic coordinates and depths as a series of current profiles in a simulation.

Once set up, the user can readily modify values as required over the duration of the mission being simulated.

Each current is defined as a 3D vector and a set of these vectors defines a complex current profile from the sea surface to the seabed.

Full horizontal and vertical interpolation is supported, which allows the current’s strength and true direction to be calculated and monitored at any point in the current field.

Full story…

 

Kathleen Munson –

I returned from Hawai’i in mid-December with 700 bottles of seawater.

The bottles hold what I hope are solutions to an abiding mystery. In the middle of the ocean, waters at depths ranging from 100 to 1,000 meters contain high concentrations of the toxic form of mercury that accumulates in fish. Nobody knows why it’s there or where it comes from.

Mercury is unique among metals because it easily changes form between gas, liquid, and solid. It also exists in various chemical forms when it is dissolved in water.

One of those forms is monomethylmercury, which is found at high concentrations in the tissue of some fish and can have detrimental health impacts on people.

In particular, monomethylmercury hinders the neurological development of fetuses in pregnant women who eat large amounts of these fish.

However, monomethylmercury is very different chemically from the elemental mercury that is released from the burning of coal. The pathway between smokestack and fish is full of mysteries.

One mystery is where and how elemental mercury (Hg) takes on a methyl group (CH3) and is transformed into monomethylmercury (HgCH3) in marine environments.

Scientists do not know whether the monomethylmercury in the open ocean is made on location or whether it is brought into the ocean from the shore by currents.

The answer may lie within my bottles. Only a few scientists have measured monomethylmercury in the ocean, and they have found that the highest concentrations of monomethylmercury occur at mid-water ocean depths where oxygen concentrations are lowest.

These low-oxygen zones are created when plants and animals that grow at the ocean surface die.

They sink to mid-water depths and decompose, releasing large amounts of organic material to be recycled by marine bacteria. In that process, the bacteria use up oxygen.

This creates a complex environment where many different factors could trigger mercury methylation.

Full story…

 

The Jakarta Post –

Rescue crews have saved 28 people from the water off Papua New Guinea’s northeast coast after a ferry sank Thursday with as many as 350 people on board, officials said.

The MV Rabaul Queen went down when traveling between the coastal towns of Lae and Kimbe after it sent a distress signal early Thursday, PNG’s National Maritime Safety Authority (NMSA) said.

Rescue coordinator Captain Nurur Rahman said four merchant ships were delivered to the scene by Australian authorities to help with the rescue.

“They have rescued 28 people who are now on board one vessel,” Rahman said.

“I cannot confirm or deny the 350 missing number, it is hearsay. I have not seen the manifest as yet, but it is likely around 300,” he added.

Australian Prime Minister Julia Gillard said there were 350 people aboard and that Australia was providing assistance to its near neighbor, without elaborating on that help.

“This is obviously a major tragedy,”she told reporters in the Australian city of Melbourne.

“Given the likely very high loss of life here, I ink when this news comes to the attention of Australians around the country they will be thinking about the people of PNG as they respond to this tragedy,” she added.

Rahman said he was being fed information from an NMSA agent on board one of the ships.

Full story…