Here's a crossover story for you. (nice photo on the site...) Btw... Frogner et al 2001 has a nice paper on this...
http://www.takepart.com/news/2010/04/16/is-ash-from-the-iceland-volcano-good-for-the-ocean Is Icelandic Volcano Ash Good for the Ocean? Ben Murray | 2 days ago | Comments (1) | Flag this The Current By now, you may know that airborne ash from the volcano that erupted through Iceland's Eyjafjallajökull glacier this past Wednesday is like floating Kryptonite for airplanes. The ash clogs engines and threatens aeronautic safety. And in the right concentrations, it can be bad for both people and animals when it lands. The falling cinders—a mix of crushed rock, glass and some toxic chemicals—are considered generally bad for the body. So what happens when this particulate cloud of doom settles on the surface of the ocean? You might picture it creating a floating blanket of poison that would give the people at Ocean Conservancy cardiacs. But does it? volcanic_ash1 A plume of volcanic ash rises into the atmosphere from a crater under about 656 feet ice at the Eyjafjallajokull glacier in southern Iceland April 14, 2010. A huge ash cloud from the Icelandic volcano turned the skies of northern Europe into a no-fly zone on Thursday, stranding hundreds of thousands of passengers. Photo: Olafur Eggertsson/Reuters Well, according to several scientific studies, the ash could actually be good for oceans. What? It’s like something dreamed up by the people from Union of Concerned Scientists, but this 2001 report, which looked at the effects of an earlier eruption in Iceland, shows that the ash could act sort of like an ocean fertilizer, feeding the waters’ most basic organisms. When it comes into contact with seawater, volcanic ash releases large amounts of phosphate, iron, and other “macronutrients and ‘bioactive’ trace metals,” which can support microscopic biological life, like phytoplankton. “This study shows that the initial dissolution of volcanic ash in seawater provides an external nutrient source for primary production in ocean surface waters that may stimulate biological drawdown of CO2,” reads the conclusion. That’s a lot of science-speak, so TakePart asked Kathy Barbeau, a marine bio-geochemist who specializes in trace elements in seawater at the Scripps Institution of Oceanography in San Diego to explain. On the "primary production," the ash can support, Barbeau says: “That’s essentially a measurement of the amount of carbon that is ‘fixed’ by the marine phytoplankton. By that we mean carbon, as CO2, that is converted into phytoplankton biomass via photosynthesis.” Well...that was still pretty science-y. So Barbeau broke it down further: primary productivity, essentially, is the process by which the seas’ most basic organisms turn one of their main building blocks, carbon, into body mass. For the complete process, it also needs the sun and various nutrients—which the ash can drop on the surface in large amounts. Of course, too much of those nutrients at once can create an ocean dead zone, but the Iceland eruption doesn't appear to have the potential to make that a threat, she says. On the ash-as-fertilizer front, a 2007 study by a group of European scientists followed up on the 2001 results, and their title says it all: Subduction zone volcanic ash can fertilize the surface ocean and stimulate phytoplankton growth. Regardless of what a subduction zone is, in the right places, with the right components, a descending cloud of volcanic ash can create a smorgasbord for phytoplankton, the base of the oceanic food chain that in turn feed larger and larger species… So volcanic ash, in the right concentrations, could save the world. That’s going a bit far, and of course there are caveats. For instance, without actually knowing the particular chemical makeup of this Icelandic ash and the water column it settles on, it’s hard to know what effect this particular eruption will have, Barbeau says. “There could be toxic substances in this ash. Copper, for example, is a toxic trace element, and potentially the minerals in this ash might release something that could actually inhibit phytoplankton growth.” And certainly a whale taking a big swallow of waterborne cinders might find itself with some side effects, or at least a lot of dirty baleen. But airborne nutrients that originated in the core of the earth settling down to feed the ocean’s most basic life forms? That’s a solid example of a natural cycle. Quick Study: Ocean Pollution | Ocean Dead Zones Related Stories: Iceland Moves Full Steam Ahead | Volcano Power As a Renewable Energy Source -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
