He may be a historian by training, but Dr. Ralph Harrington really gets his blood pumping by studying volcanoes, a past time that has followed him since seeing his first volcano Vesuvias alongside the Bay of Naples when he was very small.
He seems to know quite a lot about the connection between volcanoes and marine life too. Through this Q&A with him, I learned that 80% of the world's volcanoes are beneath the ocean, many volcanoes are often associated with saltwater, but freshwater too, and that ocean acidification is often increased by volcanic activity (he points out a huge example in the interview below.)
To appease his insatiable curiosity for volcanoes and earth science, Dr. Harrington started the Volcanism blog--the kind of blog he wished for in the past, but created himself.
Volcanoes and marine biology: Truly an ever intriguing topic, and one that has become even more fascinating thanks to Dr. Ralph Harrington.
Why study volcanoes?
There are countless reasons – volcanoes are such many-faceted and fascinating phenomena. Volcanism has played a key role in shaping the world around us: whatever processes you look at, from the shaping of the continents to the creation of the Earth’s oceans and atmosphere, volcanism has had a role to play. The organic building-blocks of life itself may owe their existence to volcanic activity in the oceans. Then there is the question of how humanity lives with volcanoes: the risks they pose, the benefits they offer. Finally, I would mention the cultural and historical aspects of volcanoes, their role in art, religion, the human imagination.
Does your research on and fascination and experience with volcanoes connect or relate to the marine world?
Perhaps here I should mention some personal influences. The first volcano I ever saw was Vesuvius, when I was a small child. The Bay of Naples region, with its deep and complex geological and human history, and that image of the sea, the volcano and the town spreading itself between the two – these have always remained in my mind as an archetype of the interaction between volcanoes and human society, which is where my fascination with volcanoes begins. As a historian I have researched the development of ideas about volcanoes in the eighteenth and nineteenth centuries, when debates about the supposed role of the sea in volcanic activity were at the core of disputes between those who believed volcanoes were unimportant superficial phenomena and those who saw them as fundamental geological processes. My work as a historian and my fascination with volcanoes continually seem to bring me back to the marine world.
What would the world be surprised to learn about volcanoes existing in or near the ocean?
Perhaps how many of them there are, for a start. It’s been estimated that 80 per cent of the world’s volcanoes are beneath the oceans. These submarine volcanoes are very active, and in some cases surprisingly explosive. Very recently there has been some interesting news coverage of West Mata, a submarine volcano at the northern end of Tonga Trench in the south-west Pacific that U.S. scientists visited in remotely-operated submersibles in the spring of 2009. The vents at West Mata are over a kilometer below the surface, where the pressure should be too great for explosive activity, and yet the video these scientists shot shows the volcano roaring away like a firework display. The reason must be in the volatility of the magma, but surprises like this show how much there is still to explore and understand about submarine volcanism.
Of course, even when volcanoes are not beneath the seas, they like to cluster in oceanic settings, as anyone looking at a map of the Earth’s volcanoes will notice. Most of the active continental volcanism on the planet is near the sea, because of the role of plate tectonics: heavy oceanic crust is subducted beneath lighter continental crust, so that classically you get a trench in the seabed and a line of volcanoes offset from the trench, fed by magma that rises from the subduction zone to the surface. Those volcanoes may be in the coastal region of a landmass or in a chain of islands: if you look down the Pacific coast of Russia, along the Kuril Islands and down through Japan, you can see how the volcanoes crowd along the coastal areas and island chains. Indeed, practically the whole Pacific Ocean is circled by regions of active volcanism, the famous Pacific ‘Ring of Fire’. It’s understandable that some volcano-watchers of previous ages thought that the sea directly drove volcanism, when you look at how many volcanoes are in marine settings.
And people might be surprised by how important the relationship between volcanoes and water is, even when not directly concerned with the seas. Hydrovolcanism is an important aspect of volcanic activity, the relationship between volcanic activity and rainfall is a very important one, and many volcanoes are associated with bodies of fresh water. Crater lakes, often rendered highly acidic by volcanic emissions, are a whole area of study – and of potential volcanic hazard – in themselves.
How does having a volcano in the area affect the marine life there?
Superficially, it would appear that an active volcano is a disaster for the life around it, in a marine setting as much as on land. A volcano might erupt on an island and destroy everything living there, or a flank collapse could produce a destructive tsunami; ashfall or acidic emissions might destroy life in a lake or an area of ocean. But there’s much more to the interaction of volcanoes and marine life than that, and it is far from being all a tale of destruction.
As I mentioned earlier the building blocks of life on this planet may owe their very existence to marine volcanic processes. As we’ve come to know more about spreading ridges, black smokers and other aspects of submarine volcanism we’ve come to realize that an active volcano in the ocean does not result in a dead zone – anything but. Life is highly dynamic and will adapt to whatever conditions it finds itself in. The relationship between life and volcanism is an excellent example. Despite the poisonous and acidic emissions, heat and disruptive activity of active volcanism, certain forms of life flourish around volcanoes, relishing the heat and thriving on the emissions. Volcanism has been part of the marine biosphere for as long as there has been such a thing, and until plate tectonics grinds to a halt and the last volcano goes cold, marine life and volcanism will continue to get on fine.
You recently wrote a great blog entry in September about how a volcano in the Pacific is causing ocean acidification. What other issues (marine conservation, climate change, etc.) can a volcano in or near a body of water cause.
‘In or near’ is an important distinction. A volcano in the water directly impacts upon its composition and behavior – acidification is an example, and this has a clear effect upon the life around it. A volcano near the water will impact upon it indirectly: its ash will fall into the water, flank collapses and lava emissions into the ocean can have a destructive impact, at least in the short term. These issues affect lakes near or in volcanoes as much as bodies of oceanic water. Ecosystems can be disrupted by volcanic activity, and will take time to adapt and recover. As for climate change, that’s a very big question! Climate is dynamic, not static, and volcanoes are an important factor in the ways climate changes over time. The more we study and understand the role of volcanoes in climatic variation, past and present, the better we will understand what is happening now and may happen in the future. And don’t forget, volcanoes have the capability to affect climate both gradually and catastrophically. Earth’s geological history, and the history of Earth’s climate, is punctuated by global volcanic cataclysms – that is, they would be cataclysmic for humanity. The planet rolls on regardless.
How do these volcanoes affect marine life?
A recent eruption in Tonga left fish and marine birds dead for miles around; likewise, the eruption of Kasatochi in the Aleutians turned a formerly thriving island ecosystem into an ash-covered wasteland. But life returns and adapts immediately: as in the case of Mount St Helens on land, volcanic activity at sea may seem to offer nothing but destruction but in fact it is part of the natural cycle of change and renewal. Undersea volcanism itself produces nutrients, recharging the water with the materials it needs to sustain life.
The case of the acidification of the ocean by volcanic activity is an interesting one. The example I wrote about in the blog post you mention above was Maug in the Marianas Islands. Here the acidity of the upper 100 meters of the ocean has been increased 30% by volcanic activity: many organisms cannot live in such conditions at all, and corals and shellfish that do survive there have to use much more energy to sustain their shells. In a study of a Japanese submarine volcano called Eifuku scientists found that mussels were in effect cannibalizing their shells for the carbonate they needed for their internal chemistry, with the result that their shells were very thin and weak. It’s important that we know about these effects, and are aware of how life adapts and changes in acidified ocean environments.
Is there anything the average person can do to help protect marine life and/or the ocean in areas where there is threat of a volcano eruption?
The average person should always be doing what he or she can to understand the world about them, geologically, biologically and in other ways, so that every response to environmental change of whatever kind can be an informed response. But volcanic eruptions are part of the natural world, not a threat to it, in the seas and elsewhere, and there is little anyone can do about them. In a limited way there might be a role for human intervention in some particular cases: in the Galapagos Islands, for example, particularly destructive volcanic eruptions might lead to the evacuation of the local tortoises, and in Japan recently albatrosses from a colony on the active volcanic island of Tori-shima were recently transferred to another island where they will not be threatened by volcanic activity. But generally speaking marine volcanic eruptions offer people little opportunity to do anything directly – except study, observe, and learn.
Finally, and this applies to marine and other environments, it’s worth making the point that human life needs protecting as well. Many volcanoes are in poor parts of the world, where the condition of the people is not helped by the pressures of irresponsible tourism, even if it is well-meaning. Volcano tourism is increasingly popular, but if you travel to areas such as the islands of the Pacific, Central America, or Indonesia, do it in a way that helps the people who have to make a living there – go with a professional sustainable travel company or tour organizer, there are many to chose from these days. And while we’re on the subject, even volcanoes are not free of the plague of litter, and I’d want to echo what Mathias Koester (who blogs as The Lost Geologist) said in your interview with him: wherever you go and whatever you do, take your rubbish away with you!
[Interview by Ava taken from thereeftank.com]
Enjoy!
