New theory on the formation of the Hawaiian Islands
Hello friends! (I am not your Vaiti-viti-vigi-van Girl.)
I have recently rediscovered the desire to selfishly post my thoughts and doings on this blog for others (who care) to read.
An update on me: I am most of the way through my first year as a masters student at the University of Oregon. I continue to study physical volcanology and my thesis project focuses on the eruption of Cinder Cone in Lassen Volcanic National Park, California. But more on all of that later – let’s talk about Hawai`i.
I have missed my time on the Big Island, learning hula, finding friends, and knowing Kilauea. Currently, the hole in the summit holds a deep lava lake and Pu`u `O`o has been very active – filling and draining a lava lake. Please watch this awesome video of filling/draining cycles taken with a thermal camera – it will make you want to be there. Another totallywickedawesome event (that will make you want to have been there) happened back in March of this year when the floor of Pu`u `O`o collapsed and a new fissure broke out to the southwest of Pu`u `O`o. This new fissure system, beginning on 5 March, became the Kamoamoa fissure system/eruption and lasted for only a few days. By 10 March, there was only fume, no lava flows. Still, though, the eruption included low lava fountains, spatter ramparts, giant cracks in the ground, and long lava flows that created forest fires. I don’t believe anyone or anything was injured or destroyed (besides some trees, but who likes biology anyway? 
).
If you are interested, check out the daily Eruption Update for Kilauea’s most recent happenings and HVO’s Kilauea Images page has so many cool pictures and video, for the intrepid volcano investigator (which is where I found the links above).
Another purpose of this post is to *briefly* describe a new theory on why Hawai`i exists. The current generally accepted theory is that intraplate volcanism is created by mantle plumes that form hot spots on the surface of the earth. Mantle plumes are upwellings of hot magma (or almost magma) from somewhere deep within the mantle that melt and erupt when they reach the surface, forming island chains like Hawai`i in the middle of tectonic plates. These plumes are assumed to be stationary (not necessarily a good assumption) and conduit-like. Cao et al. (2011) in a recent article in Science argues that “conduit-like” may not be an appropriate description. This article will explain it for you, but the basic idea is that the authors used seismic waves and how they are reflected and refracted within the earth to take a “picture” of the subsurface beneath Hawai`i and its surrounding area. This picture (or “these pictures” is more accurate) shows a “thermal anomaly” (as in, a hot or cold body that’s not “supposed” to be where we find it, something unexpected) that is 800-1,200 kilometers wide, not a conduit-like feature as hypothesized by the mantle plume theory. The authors’ proposed idea is that the warm mantle rises and accumulates at a transition zone, or mineralogical boundary, in the mantle (similar to how magma that feeds subduction zone volcanoes is sometimes hypothesized to pool beneath the crust and then rise up and erupt). This warm mantle then gets taken up and erupted as Hawaiian volcanoes.
This is an important finding (though those that know what they are talking about have argued that there is too much error in the data used in this interpretation) because geologists use island tracks to reconstruct tectonic plate movements of the past. If this hypothesis turns out to be more consistent with the data already collected and yet to be collected, these island tracks may not be as useful to us as signs of a shifting plate. But, as always, more data is still necessary to make one or the other the dominant theory. And, as always, it may turn out to be neither or both; such is the progression, quandary, and beauty of science.
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I hope to reawaken this blog and post volcanologic articles/pictures/videos/etc. that I find thought-provoking and/or totallywickedawesome. I hope to use this blog to think deeper about aspects of volcanology and to brainstorm about my current and future research. I hope to also challenge you, reader, with questions of my own and I welcome any ideas, questions, and criticisms – my view on science is that it is collaborative, open, and respectful.
So, until something else strikes me as blog-provoking, may the earth-fire be with you.
