This article is brought to you by Ms Jessica Klar, a PhD. candidate (Geochemistry Group) here at the National Oceanography Centre.
Jessica’s Klar NOC profile page: http://noc.ac.uk/people/jk2e09

Many of you might remember the European flight disruptions caused by the volcanic eruption of Eyjafjallajökull (Iceland) from the 14^th of April to the 22^nd of May 2010. Approximately 270 ± 70 ⋅ 10⁶ m³ of volcanic ash loaded with metals got expelled into the atmosphere and spread south-eastward over the Ocean and Europe.

Ash fall-out might have had a significant influence on the primary production in the high latitude North Atlantic Ocean. We had the very rare opportunity to investigate trace metal distributions and primary production rates in this area at the time of eruption during three cruises on the RRS Discovery.

The high latitude North Atlantic Ocean is described as a seasonal HNLC (high nutrient, low chlorophyll) region, where iron stress develops in the peak and post bloom stages during summer. Primary production can only be stimulated by ash if it adds a previously limiting nutrient to the surface ocean. During the volcanic eruption highly elevated concentrations of dissolved iron (an essential micronutrient for marine phytoplankton) and dissolved aluminium (a tracer for aerosol inputs), as well as high photosynthetic efficiencies, were observed directly under the plume. Ash addition experiments have also shown enhancement of primary production.

Due to the intermittent and unpredictable nature of volcanic eruptions it is difficult to quantify its impacts on trace metal cycling in the oceans. Volcanic ash is loaded in metals and its supply to the surface ocean promotes primary production on a local and sporadic scale, hence enhancing atmospheric carbon drawdown.

You can find more information about this study in the following article:

Achterberg, E P, Moore, C M, Henson, S A, Steigenberger, S, Stohl, A, Eckhardt, S, Avendano, L C, Cassidy, M, Hembury, D, Klar, J K, Lucas, M I, Macey, A I, Marsay, C M and Ryan-Keogh, T J, 2013. Natural iron fertilization by the Eyjafjallajökull volcanic eruption. Geophysical Research Letters, 40, 921-926.

The post Enhanced primary production following the eruption of an Icelandic volcano appeared first on Exploring our Oceans .

“I had fought on behalf of man against the sea, but I realized that it had become more urgent to fight on behalf of the sea against men.”

The post Ocean Quotes 10: Alain Bombard, Biologist appeared first on Exploring our Oceans .

This is one of my favorite quotes. I find it to be absolutely true.

“It is a curious situation that the sea, from which life first arose, should now be threatened by the activities of one form of that life. But the sea, though changed in a sinister way, will continue to exist: the threat is rather to life itself.”

Rachel Carson
1907 – 1964

The post Ocean Quotes 9: Rachel Carson, Marine Biologist appeared first on Exploring our Oceans .

“With every drop of water you drink, every breath you take, you’re connected to the sea. No matter where on Earth you live.”

See Sylvia’s TED talk about future ocean conservation:

The post Ocean Quotes 8: Sylvia Earle, Oceanographer appeared first on Exploring our Oceans .

This blog is brought to you by Dr. Aurélie. Duchez, a physical oceanographer at the National Oceanography Centre, Southampton. The topic of this blog is the Atlantic meridional overturning circulation (AMOC), which the RAPID project is aimed to monitor.

RAPID data available are freely available at: http://www.rapid.ac.uk/rapidmoc/

Observed decline of the Atlantic Meridional Overturning Circulation as observed by the RAPID array at 26°N

Global ocean circulation is an important factor in climate variability and change. In particular, changes in the strength of the Atlantic meridional overturning circulation (AMOC) have been implicated in ancient climate events, as well as in recent climate anomalies such as the rapid warming of the North Atlantic Ocean in the mid-1990s.

A mooring array known as the RAPID-MOCHA array, has been deployed at 26°N between the Bahamas and the Canary Islands and has provided continuous measurements of the strength and variability of this circulation since 2004. The AMOC and its component parts are monitored by combining a transatlantic array of moored instruments with submarine-cable based measurements of the Gulf Stream and satellite derived Ekman transport (Fig. 1 and 2).

The time series has recently been extended to October 2012 (Fig. 3) and the results show a downward trend since 2004. From April 2008 to March 2012 the AMOC was an average of 2.7 Sv weaker than in the first four years of observation (95% confidence that the reduction is 0.3 Sv or more). Ekman transport reduced by about 0.2 Sv and the Gulf Stream by 0.5 Sv but most of the change (2.0 Sv) is due to the mid-ocean geostrophic flow. The change of the mid-ocean geostrophic flow represents a strengthening of the subtropical gyre above the thermocline.

The increased southward flow of warm waters is balanced by a decrease in the southward flow of Lower North Atlantic Deep Water below 3000 m. The transport of Lower North Atlantic Deep Water slowed by 7% per year (95% confidence that the rate of slowing is greater than 2.5% per year).

For more information about this work, you can find in this paper:
Smeed, D. A., McCarthy, G., Cunningham, S. A., Frajka-Williams, E., Rayner, D., Johns, W. E., Meinen, C. S., Baringer, M. O., Moat, B. I., Duchez, A., and Bryden, H. L.: Observed decline of the Atlantic Meridional Overturning Circulation 2004 to 2012, Ocean Sci., 10, 29-38, doi:10.5194/os-10-29-2014, 2014.

The post The RAPID project: Monitoring the atlantic meridional overturning circulation (AMOC) appeared first on Exploring our Oceans .

Some of you might wonder, why is it that with modern technology, diving equipment companies can’t come up with a new diving system that will allow divers to go as deep as an ROV, right to the bottom of the deepest trenches?. Well, this blog might answer your question.

Jacques Yves Cousteau once said: “The future diver will be able to move freely from the ocean surface to its depths, while he breath liquids“. This idea of a diver ventilating liquids to overcome gas compressibility effects (which are associated with normal Scuba diving, such as decompression sickness), also played a major role in James Cameron’s 1989 sci-fi film
“The Abyss”, as you can see in this video:

But are they right?.
Until the late 70’s, a lot of research examined the option of man breathing liquid by using oxygenated perfluorocarbons (PFCs) – a type of liquid that can dissolve enormous quantities of gas. The general idea is that the liquid would be contained in an enclosed helmet that would replace all the air in the lungs, nose and ear cavities. Since the 90’s, liquid ventilation techniques have been used successfully on premature babies with lungs that are not developed enough to comfortably adjust from the liquid environment of the womb to inhaling gaseous air. Nevertheless, most of research in this field on adults, reached a conclusion that the spheric geometry of the human alveoli, makes it impossible to efficiently absorb oxygen into the blood stream and remove Co2 from it. And therefor, the idea was dropped by the science community.

Another revolutionary concept of a diving system, is the one based upon the idea of using ‘artificial gills’ which will enable the diver to extract the oxygen molecules from the sea water, much like the same way that fishes do. A recent design of such a system was developed by the South Korean designer Jeabyun Yeon, and it made the news headlines. Due, keep in mind that this system is still a conceptual design and not a feasible and functional unit yet. You can read more about this system by clicking on this image:

So meanwhile, until we’ll all be free to explore the abyss with our own deep diving systems,
I hope you enjoyed week 2 and you’re excited and ready for week 3.

Eric

The post Can divers breath liquids to reach greater depths? appeared first on Exploring our Oceans .

First, let’s review some of the common renewable energy which are suggested today:
1. Solar Energy – Can be used directly for heating and lighting homes and other buildings, for generating electricity, and for hot water heating.
2. Wind Energy – Captured with wind turbines and generate electricity.
3. Ocean Energy – Tidal or wave energy, which are driven by both the tides and the winds.
4. Geothermal Energy – Uses the Earth’s internal heat for electric power production
5. Bioenergy – The energy from any decomposed organic matter. Has the potential to greatly reduce our greenhouse gas emissions.
6. Hydrogen Energy – Can be found in many organic compounds, as well as water. Once separated from water, hydrogen can be burned as a fuel or converted into electricity.

In the UK, The total of all renewable electricity sources provided 11.3 % of the electricity generated in 2012, and predicted to rise up to 15 % by 2020. In the US, renewable electricity sources provided 13.2 % of the domestically produced electricity in 2012, using the different sources as shown in this following diagram.

Latest statistics indicates that the use of renewable energy is gradually growing yearly, though will it ever replace conventional sources?. To my opinion probably not, due to renewables reletivly high cost and availability. The general world trend in energy production seems to be a combination of all the different resources such as fossil fuels, nuclear and renewable energies.
In the future, with advanced and cheeper technologies, renewables will probably be more affordable and hopefully will increase their portion as a resource and replace the use of fossil fuels.

Watch this interesting video to learn more about the future of energy:

The post The future of renewable energy appeared first on Exploring our Oceans .

“It is said by the Eldar that in water there lives yet the echo of the Music of the Ainur more than in any substance that is in this Earth; and many of the Children of Ilúvatar hearken still unsated to the voices of the Sea, and yet know not for what they listen.”

The post Ocean Quotes 7: J.R.R. Tolkien appeared first on Exploring our Oceans .

“There’s nothing wrong with enjoying looking at the surface of the ocean itself, except that when you finally see what goes on underwater,you realize that you’ve been missing the whole point of the ocean. Staying on the surface all the time is like going to the circus and staring at the outside of the tent.”

The post Ocean Quotes 6: Dave Barry appeared first on Exploring our Oceans .

Click on the image to see a video of the ROV operation that capped the Horizon well:

The post The ROV team effort that stopped the Deepwater Horizon oil spill – Gulf of Mexico 2010 appeared first on Exploring our Oceans .