Tremors, Mt. Baker and the media: The sensationalism of science
I write the Eruptions blog on Big Think. I've been mesmerized with volcanoes (and geology) all my life. It helps that part of my family comes from the shadow of Nevado del Ruiz in Colombia, where I could see first hand the deadly effects of volcanic eruptions. Since then, I've taken a bit of a winding path to become a volcanologist. I started as a history major at Williams College, almost went into radio, but ended up migrating to geology, including an undergraduate thesis on Vinalhaven Island, Maine. I followed this up by changing coast to get my Ph.D. from Oregon State University. Then I ran a MC-ICP-MS lab at University of Washington for a spell (and wrote for an indie rock website). I spent three years as a postdoctoral scholar at University of California - Davis studying the inner workings of magmatic systems. I am now an assistant professor at Denison University and have projects in New Zealand, Chile and Oregon.
I am fascinated by volcanoes, their eruptions and how those eruptions interact with the people who live around the volcanoes. I started this blog after getting frustrated with the news reports of volcanic eruptions. Most of them get the information wrong and/or are just sensationalistic. I will try to summarize eruptions as they occur, translate some of the volcanic processes that are happening and comment on the reports themselves.
And no matter what people tell you, I definitely do not have a cat named Tephra. (OK, I do).
You can find out more about my research by visiting my website. If you have any comments, questions or information, feel free to contact me at eruptionsblog at gmail dot com.
It never ceases to amaze me how the media just loves to find bad in the good (or at least the interesting). I've seen a number of article or blog posts from newspapers that proclaim that Mt. Baker is Washington is "overdue" for an eruption, so naturally I was curious "how would they know that"? Well, that lead me down a path that, as we've seen before, becomes a lot like a game of telephone, where the message is convoluted along the way.
We'll start off with the science. Nature recently published a study by Dr. Mark Jellinek (UBC) and Dr. David Bercovici (Yale) that looked at the tremors associated with magma rising in a volcanic conduit before an eruption. This study was centered on whether these vibrations could be used to help predict when a volcanic might have an explosive eruption. It is based on a model that magma moving up the volcanic conduit from depth is doing so not as a flow of liquid (like a spigot), but rather as a plug of magma surrounded by a layer of bubbles that shear as the plug is forced upwards. These bubbles are kind of like the packing bubbles in a package (see figure below) you might receive in the mail - they are a cushion along which the magma plug rests, but they don't hold the plug in place. This means that as the bubbles get squeezed, that plug might rock back and forth in the conduit as it is moving, producing harmonic tremor in the volcano. According to this new study, this tremor will increase in frequency the closer the plug is to the surface (and thus erupt). Why is this interesting? Well, if instruments sensitive enough to measure this tremor can be installed around a volcano, then it might be possible to monitor the tremor and its frequency in order to give some early warning of an impending eruption - and warning that is closer than "days to weeks". This is, of course, all theoretical right now ~ Jellinek and others are looking to test this monitoring method out on a volcano that is giving signs of an impending eruption ~ but it could be another useful tool to monitoring active volcanoes. Of course, this model only works for fairly viscous magma - andesite and dacite - rather than the less viscous (and more active) volcanoes that erupt basalt or basaltic andesite like Etna and Kilauea.
A figure from Jellinek and Bercovici (2011) showing the model for magma moving through a conduit. The layer of shearing bubbles on the edges of the plug allow for the column of magma to oscillate, creating tremors that could be used to help predict an eruption.
Of course, the media picked up on this article - it is an interesting look at developments in volcano monitoring (and it is in Nature, never forget that pull, be it as it may). However, after the initial salvo in the science media where the idea of looking at the magmatic "wagging" of a volcano was examined, some newspapers latched onto something that Dr. Jellinek may (or may not) have said about whether Washington's Mt. Baker was "overdue"*. Now, nowhere in the articles I've read does anyone directly quote Dr. Jellinek as saying, verbatim, "Mt. Baker is overdue". Sure, it has been a while since it erupted and we should expect that it will erupt again, but "overdue"? He is definitely right that if it does erupt, it will cause a mess in Bellingham, WA and likely Vancouver, BC due to ash fall - you can check out the full 1995 USGS hazard report on the volcano as well. However, it seems clear to me that an overzealous reporter jumped at the idea that a prominent volcano like Baker is primed for another eruption.
Mt. Baker is still, of course, an active volcano. It has active fumaroles at the summit and hot springs around the edifice. Currently, the volcano is still in what is called the Sherman Crater eruptive period that started in 1843 with the last confirmed eruption in ~1880. This period is mostly small phreatomagmatic explosions (VEI 2) and young tephras/bombs. There are quite a few historical reports of activity at Baker during the 19th century, but many of them are questionable, but there has been increasing in thermal/fumarolic activity at the summit. One of the most prominent was in 1975-76, when the heat flow increased 10-fold and the plumes took on a darker complexion. Prior to this period, the volcano produced a number of tephras and collapses during the Mazama Park period from 5,930-5,740 years before today. With a record such as that, it is fairly hard to say how "overdue" Mt. Baker is for a new eruption.
So, we have a fascinating article that suggests that we might be able to give people more reliable warning of the timing of an impending eruption and over a week, the news reports on the article degrades to "Baker is overdue, Vancouver is doomed!" Part of this is, clearly, the sensationalizing that the media loves to do. Part is likely just shoddy reporting that relies on the internet rather than talking directly to the sources (that might be on the same campus). Part is likely just the basic lack of understanding of volcanology and science in general by many in the media (and public). It might take a watershed event of "the sky is falling" to get the media out of the habit of turning every news report into a prophecy of destruction. It just makes life more difficult for those trying to get the real information out.
* Is there any way we can come up with another term for a volcano that hasn't erupted in a period longer than the normal interval between eruptions? "Overdue" is such a loaded word - volcanoes are not pinned to schedules, so the variability in the timing between eruptions, especially at less active volcanoes, is likely not predictable. Just something that really bugs me.
Top left: Undated image of Mt. Baker in Washington state.
Giving our solar system a "slap in the face."
- A stream of galactic debris is hurtling at us, pulling dark matter along with it
- It's traveling so quickly it's been described as a hurricane of dark matter
- Scientists are excited to set their particle detectors at the onslffaught
The climate change we're witnessing is more dramatic than we might think.
A lazy buzz phrase – 'Is this the new normal?' – has been doing the rounds as extreme climate events have been piling up over the past year. To which the riposte should be: it's worse than that – we're on the road to even more frequent, more extreme events than we saw this year.
Once again, our circadian rhythm points the way.
- Seven individuals were locked inside a windowless, internetless room for 37 days.
- While at rest, they burned 130 more calories at 5 p.m. than at 5 a.m.
- Morning time again shown not to be the best time to eat.
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