Home | Contact ST  
Follow ST

Environmental Monitoring


October 2015 Issue

Southern Ocean Affected
Ice Age Global Cooling

In the last 30,000 years there was, at times, more mixing in the Southern Ocean than previously thought, according to a study by the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI). This meant that vast quantities of nutrients were available to phytoalgae, which in turn contributed to storing carbon dioxide during the last glacial period.

The study shows that during the last glacial period, the water column in the area of the seasonal sea ice zone was more mixed in autumn and winter than previously thought. Only in the short Southern spring and summer, for just a few months in the year, was there a marked stratification at the ocean’s surface.

Up until now, researchers assumed that during the last glacial period there was a layer of freshwater created by melting icebergs that sat on the ocean like a lid all year round, which would have greatly reduced the supply of nutrients from the ocean’s depths to the surface leading to low biological production.

However, the new findings show that in the last glacial period in the seasonal sea ice zone, which was twice as large as it is today, the water was well mixed to a depth of a few hundred meters. This allowed nutrients to reach the surface from deeper levels.

In addition, melting ice in spring released the trace element iron, which had been transported with dust from South America. This created ideal conditions for microscopic, exoskeleton algae (diatoms) that used the nutrients to bind carbon during photosynthesis, and so store carbon dioxide.

When they died, these phytoplankton sank to the ocean floor thousands of meters below. In this biological pump, atmospheric carbon dixode is stored in sedimentary deposits over geological time periods. During the ice ages, storage of carbon dioxide in the Southern Ocean contributed significantly to global cooling.

New Dispersion, Water
Quality Modeling Tool

Recently, Makai completed an effort to adapt the EPA-approved Environmental Fluid Dynamics Code (EFDC) into a robust and flexible dispersion and water quality modeling tool. The new Makai EFDC modeling system (M-EFDC) is designed to simulate and predict the dispersion of large industrial water flows. It enables cost-effective modeling solutions ranging from initial project planning to more rigorous regulatory submittals and watershed management efforts.

The M-EFDC model simulates aquatic systems in three dimensions across a wide range of sizes and time scales. The results are used in the design, planning and permitting process for the intake or discharge of a variety of facilities, including: desalination, seawater cooling systems, LNG processing plants, petroleum refineries, traditional thermoelectric power plants, pulp and paper mills, chemical manufacturing plants, food processing plants, and metal manufacturing plants.

Indian Ocean
Security Warning

The security situation in the Indian Ocean could very quickly change for the worse, according to MAST.

“The current security framework is working, but it remains extremely fragile and dependent on international navies maintaining a presence in the Indian Ocean, Best Management Practice 4 (BMP4) being diligently applied, and for at least the majority of vessels to be protected by armed guards,” said Gerry Northwood, COO of MAST. “Yet we continue to see speculative approaches by skiffs equipped with assault rifles and ladders. There are other warning signs indicating the security situation could deteriorate.”

Alan Cole, an official at the United Nations Office for Drugs and Crime, recently expressed concern that illegal fishing in the Indian Ocean and Horn of Africa might be a catalyst for a return to piracy.

In July, Kenya released a number of convicted pirates enabling them to return to their homes in Somalia.

“Released pirates are reportedly seeking work as armed guards in oceangoing fishing vessels,” Northwood said.

Repeat Order for Exhaust
Cleaning Scrubber Systems

Finnlines has contracted Wärtsilä to supply three of its vessels with exhaust cleaning scrubber systems. This is a repeat order, with delivery expected in early 2016.

The system selected is Wärtsilä’s Hybrid in-line scrubber system, providing the flexibility to operate in both open and closed loop modes. The compact in-line version also provides an efficient space- and weight-saving solution.

Funding to Set Up
Climate Change Center

University of California, San Diego has received a charitable gift from Richard and Carol Dean Hertzberg of $5 million to establish the Center for Climate Change Impacts and Adaptation at Scripps Institution of Oceanography.

The center will provide science-based strategies for adapting to climate change and will focus on how society can address the consequences that are already unfolding or appear to be inevitable. These consequences range from sea level rise to more extreme weather with the potential to disrupt commerce, agriculture and the habitability of certain regions on a large scale.

Successful Trials
For GeoWing

Fugro has undertaken successful trials of its new GeoWing, designed to detect low-ferrous content unexploded ordnance (UXO) items in challenging marine environments. The system is especially beneficial for subsea construction projects, such as wind farms and cable route developments, particularly in magnetically “noisy” marine environments and areas affected by strong tidal currents.

The magnetic signature from small items of UXO can often be masked by the magnetic signature of other sources, such as the background geology. The GeoWing, a fixed gradiometer array consisting of five magnetometers mounted behind an ROTV, detects variations in both vertical and transverse magnetic gradient, which enables the ferrous signature from background geology and motion noise to be almost entirely removed from the analysis.


-back to top-

Sea Technology is read worldwide in more than 110 countries by management, engineers, scientists and technical personnel working in industry, government and educational research institutions. Readers are involved with oceanographic research, fisheries management, offshore oil and gas exploration and production, undersea defense including antisubmarine warfare, ocean mining and commercial diving.