Jul102009
Point of Eruption
Written by Ava

I've had the privilege of interviewing marine biologists, conservationists, evolutionists, and scientists.  Where to go from here?  Now that our Marine Geology has "erupted" onto the scene (pun totally intended), we're doing a Q&A with Dr. Erik W. Klemetti, a postdoctoral researcher at the University of California who studies volcanism.

Yep, that's right, he studies all aspects of volcanoes from why it takes a certain amount of time to drive a particular volcano to erupt to the marks and ridges that erupted volcanoes leave behind.

"I am fascinated by volcanoes, their eruptions and how those eruptions interact with the people who live around the volcanoes," Dr. Klemetti writes on his blog Eruptions.

When we had the opportunity to do a Q&A session with Dr. Klemetti himself, we wondered if studying volcanoes had anything to do with marine science.  And in fact,Dr. Klemetti says he is "intimately involved" with water in his research and can certainly wax poetic on mid ocean ridges, submarine volcanism, and mineral deposits left by volcano eruptions.  

We're exploding with excitement over this! Give it a read.

What is your background and why particularly volcanoes? 

 

I started my academic life at Williams College where I majored in both geology and history. I was a late arrival to geology as an undergrad, but I clicked with the discipline quite quickly and completed an undergraduate thesis on some 350+ million year old volcanic rocks on Vinalhaven Island in Maine.

After that (and a year away from geology), I headed to Oregon State University to get my Ph.D., focusing on volcanism in the Andes of Chile. Oregon State is one of the top schools in igneous petrology (the study of molten rocks, more or less) and oceanography, so I was exposed to a lot of both, although the former was clearly my focus. After finishing at OSU in 2005, I ran a lab at University of Washington before heading to UC Davis for the postdoctoral research position I’ve been in since 2006. I’ll be headed off to Denison University in Ohio in August 2009 to start as an assistant professor in the Geosciences Department.

Now, the tricky question ... why volcanoes? This probably has more to do with my personal background. My mother’s side of the family is from Pereira, Colombia, in the shadow of Nevado del Ruiz. I remember seeing the mountains from my grandmother’s and after the deadly eruption of Ruiz 1985, seeing the destruction at nearby Armero. Since then I suppose I’ve had a fascination with volcanoes. On the other side of my family, my paternal grandmother was an avid “rock hound” so I likely picked up my interest in minerals from her (along with a hefty mineral collection).

Your bio says your main interest is connecting time with chemistry in magmatic system in order to unravel timescales that produce a volcano.  Do bodies of water or the erosion and deposits left by bodies of water have any involvement with this?

Actually, water is intimately involved with the research I do, but mostly in the form of magmatic water (dissolved in magmas) or meteoric water that can alter rocks. Meteoric water is especially interesting because most water in hydrothermal circulation at a volcano (hot water cycling through the crust) is meteoric water. This water can alter the composition of the rock along with help with the precipitation of metals in rocks forming ore deposits. Another aspect is that the magma under the volcano can sometimes assimilate altered crust into the magma, and we can see that signal in the composition of the magma erupted - if we can connect that to time, then we can start to map the evolution of the magmatic system under the volcano, which is not well-understood at this point.

When most people think volcanoes, they think mounds of lava a top a giant mountain…they don’t usually think it has anything to do with bodies of water or the ocean. How do you prove them wrong?

There are any number of examples of the important relationship between volcanism and bodies of water. Many volcanoes have crater lakes (such as at Ruapehu in New Zealand, South Sister in Oregon and most famously at Crater Lake in Oregon). These lakes can be used as a gauge of magmatic activity at the volcano as the chemistry of the water can change as dissolved gases get released into the water of the lake. Some crater lakes can become extremely acidic thanks to the dissolved sulfur and hydrogen in the gases, some as low as pH of 1 or 2. Others can be extremely pure, as at Crater Lake, where the water is the clearest of any body of water in the world. At lot of the difference has to do with the volume of water and the activity of the volcano. Crater Lake as a lot of water (the lake is 7 km across) and small amounts of gas entering the lake, so the lake is dominated by snow melt.  

These crater lakes can also be hazardous as well. Dissolved carbon dioxide at the bottom of Lake Nyos in Cameroon was catastrophically released by a lake overturn in 1986. The carbon dioxide moved downhill (as it is denser than air) and suffocated 1,700 people. There is also the threat that if a crater wall is breached, then there might be a catastrophic release of water from the top of a volcano, producing a lahar (volcanic mudflow). Events like this have happened at Ruapehu in New Zealand in the last 100 years. The crater lake at Ruapehu is carefully monitoring, with volcanologists checking the temperature, depth and chemistry of the water regularly.

Do bodies of water suffer when volcanoes erupt near them?  

As you can tell from the answer to the previous question, they can definitely suffer. Another problem is that ash can easily contaminate water supplies for people and animals. This is one of the most hazardous results of a volcanic eruption - the disruption of water and food supplies.

Where has your research taken you and what can you tell about the bodies of water in those regions and how they are affected by volcanoes?

My research has taken me to Penobscot Bay in Maine, the Andes of northern Chile, the central Oregon Cascades along with the Taupo Volcanic Zone in New Zealand. In New Zealand, most of the major calderas are occupied by lakes currently, such as Lake Taupo and Lake Okataina. Although we have yet to see a large eruption in New Zealand since humans arrived, you can be sure that if Taupo were to erupt again, it would have a dramatic effect on the lake. When Mt. Tarawera near Lake Okataina erupted in 1886, it destroyed a large portion of Lake Rotomahana with large explosions. Now, many of these explosion pits are filled with new lakes, such as Frying Pan Lake in the Waimangu Valley, a lake that is hope enough to steam off the surface!

In the Andes, the most impressive feature related to water might be the areas that used to have water. The northern Andes in Chile are littered with dry lake beds called “salars” that were likely last filled during the last major glaciation, but today are dry, salt flats that are mined from the salt.  

What have you learned about the effects of climate change through working with volcanoes?

I could probably fill a book with what I’ve read concerning the relationship between volcanoes and climate change. All I will say right now is that volcanic eruptions have been affecting the climate since the planet was formed and will continue to do so. Our understanding of how the climate might change after a large eruption continues to change and especially how much volcanic factors might enter into our current state of climate change.  

Tell me about your blog Eruptions.

Eruptions started innocently enough after I became frustrated how few volcano-related websites/blogs are written by geologists. This is not to say that they don’t provide excellent information. Blogs like The Volcanism Blog (volcanism.wordpress.com) and Volcano Live (www.volcanolive.com) are excellent sites. However, with all the mangled science in mainstream media, I started Eruptions as an attempt to bring some clarity to the news of volcanic eruptions worldwide. Needless to say, when I started the blog in May 2008, I never would have guessed that a year (and change) later I would be on ScienceBlogs and getting over 50,000 visits a month!

What is underwater volcanism like? Your knowledge is in mid-ocean ridge volcanism and submarine volcanism.  Explain what that means.

Currently, much of what we know about undersea volcanism is circumstantial because until recently, geologists hadn’t caught many submarine eruptions in progress. However, we know have seen more direct evidence for volcanic eruptions under the sea, to the point that we might even have a new name for them: Neptunian. These are explosive eruptions that occur below the surface of the ocean in places that many thought “explosions” were not possible due to the pressure from the overlying water. A recent paper in Geology (Allen and McPhee, 2009) describes vast undersea pumice flows driven by density changes as the hot volcanic material is erupted into the water column, then collapses as it cools.  

This is only one of many types of subaqueous volcanism. There is also mid-ocean ridge volcanism that might actually be the most important volcanic system on the planet. The mid-ocean ridges run along the bottom of the ocean basins where plates are spreading apart. Magma rises up underneath the ridge and erupts, pushing the plates incrementally further apart each time - it is how ocean basins form. We’ve actually never seen a mid-ocean ridge eruption in action as they are deep in the ocean basins. There has been some circumstantial evidence of eruptions such as changes in seawater composition and temperature, biota blooms and instruments being “taken for a ride” in a lava flow, but no actual footage/witness of a mid-ocean ridge eruption. However, we know they happen because the ocean basins are still growing and we have a lot of seismicity on places like the Mid-Atlantic Ridge and the East Pacific Rise, two prominent mid-ocean ridges.

How do volcanoes in the ocean affect the marine inhabiting it?

Again, you could fill volumes with this subject. Life on Earth likely started in the ocean near volcanic vents such as the “black smokers”  that have been found on mid-ocean ridges - places where hot, mineral-rich fluids come out of the sea floor. These fluids are heated by the volcanism on the ridges and where we find these “black smokers”, we find all sorts of life that doesn’t need the Sun to survive. They extract energy from the minerals/nutrients (such as sulfur) in these hot hydrothermal fluids - or live off the biota that lives off the nutrient-rich fluids. The communities almost look alien to us, but they thrive at the bottom of the ocean thanks to the volcanic activity. As the volcanic activity wanes and the black smokers stop, the life dies or moves on - they are directly connected.

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