Monday, September 26, 2011

Volcanic Mechanics

So the last post sort of told you where I was going with this thing. There have been many reports in the news lately about volcanic eruptions, from Eyjafjallajokull in Iceland, to lesser known volcanoes such as Nabro in Eritrea (which had no prior historical records of having erupted). Due to the nature of the Internet, and the speed at which information travels nowadays, it could seem to the layman that volcanic eruptions, earthquakes, and other natural disasters are on the rise.

While it makes for good tabloid news, this is simply not the case. The earth has many, many active, and dormant volcanoes. They did not get to be the size that they are by being eternally quiet, sleeping giants. In fact, the very earth you're standing on was born of fire. This is a normal process, and if you look at the historical record of eruptions, you would actually see that eruptions are decreasing due to the cooling of our planet (obviously the surface is not molten, a result of our planet slowly cooling over time internally).

However, this does not mean that eruptions shouldn't fascinate, and even terrify you. Indeed there are some DANGEROUS volcanoes out there that should they erupt WILL result in mass casualties. Vesuvius is a murderer, and since its famed eruption in Pompeii, and the eruption of WWII, it has remained quiescent as the population grows around it. If Vesuvius has a major eruption, there is no possible way to properly evacuate the millions of people who live around it. The same is true for stratovolcanoes in the Cascades ranges, like Shasta, or Ranier.

Media coverage of volcanic eruptions has been made very easy with the advent and implementation of the Internet, cell phones, and bloggers around the world. Indeed, many reports are first hand, and accurate, however many are from areas of the world where there is no accountability for the things you write. The country of Niger recently had an interesting report of a supposed volcanic eruption in an area without any previous history of volcanic eruption. Reports turned out not to be true. There is another blogger who routinely spreads misinformation and uneducated guesses, and gets a lot of attention (dutchsinse), and recently caused quite a hubub when he claimed that the Pisgah Crater in California was in an eruptive phase. The USGS subsequently was 'forced' to respond to his hype, and publish *actual* scientific data to shut up this loon. Unfortunately he took this as a declaration of war on his ego, and decided to actually campaign against the USGS.

Understanding what constitutes a volcanic eruption or activity is key to making good reports, good predictions (although predicting volcanic activity is FAR from accurate at this point in our history). Bloggers like Dutchsinse have a knack for convincing themselves, then convincing the idiots out there that they are on to something that millions of dollars worth of seismic equipment and satellite monitoring somehow failed to catch. This is simply not the case. You'd have thought that a volcanic eruption just east of Los Angeles would be HUGE news, suspiciously, there is none... or maybe thats no suspicious at all given that the area has not erupted for over 6000 years. That's not to say an eruption can't happen or wont. Chaiten volcano in Chile erupted after over 8,000 years of dormancy, proving that point. But it erupted violently, and without any prior warning other than a few smallish tremors.

In any case, there are actually GOOD online resources out there for volcano monitoring and good reporters out there that are ACTUAL scientists and volcanologists. Some of the good resources out there have very close to real time updates, and some others mostly report on only significant eruptions. The Smithsonian (http://volcano.si.edu) has a weekly report of all new and ongoing activity. The Global Volcanism Blog is a fairly good one to read as well. If you're into Icelandic volcanic activity and were as fascinated by the unexpected eruption of Eyjafjallajokull as I was, then you might check out the blog of Jon Frimann (http://www.jonfr.com/volcano) who usually has a good number of articles on the current state of Iceland's volcanoes and fault lines.

When reading about volcanic eruptions there are several things to consider. Your source, you own background knowledge about the subject, and any motivation for writing an article. It's also important to filter out hype. Mainstream news media is NOT a good source for volcanic reporting as they often embellish speculative opinion, or attempt to have some meteorologist predict eruptions... all of these things should be ignored.

Volcanoes operate on many different factors, and it is important to understand the different types of volcanoes, and how they work. You have subduction fault volcanoes that typically result int he formation of a stratovolcano, like the kinds found in the Pacific Ring of Fire. There are hotspot and sea-floor spreading volcanoes that occur when a mantle plume breaks through the crust usually along a fault, such as in Iceland, or Hawaii. There are supervolcanoes, which much like the mantle plume type, have a large silicic magma chamber such as Yellowstone Caldera or Toba in Indonesia, which take a very long time to 'charge up', and blow. Then you have monogenetic volcnic fields like Michoacan-Guanajuato in Mexico, where numerous small cinder cones such as Paricutin erupt once, then never again. There are rarer types of volcanoes as well, such as Ol Doinyo Lengai in Africa which erupts carbonatite lavas, the only known volcano in the world that currently erupts these strange lavas.

The point is, knowing the type of eruptions your volcano is capable of having is important to cross referencing the validity of any eruption report. Although many times, a picture is worth a thousand words, an a video even more so.

My next blog posts will focus more on specific eruptions, and I will report on those citing viable sources.

Up next: Tambora Volcano, Indonesia's sleeping killer.

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