Volcano Blog by Tom Pering
  • Blog
  • About Me
  • Publications
  • Slug Calculator

Why is gas so important in volcanic eruptions? 1) Strombolian Eruptions

16/10/2012

 
I am now a few weeks into my PhD and am enoying it tremendously, it's certainly great enjoying what you do! As my PhD is based around gases and their importance in volcanic systems worldwide, I thought I would produce a series of posts on why they are important in specific volcanic eruption types and touch upon what they can tell us outside of eruptions. 
Picture
Firstly, a brief discussion on Strombolian eruptions.  

The classic example of the Strombolian eruption is from the Island of Stromboli, Italy and I am sure if you search google images you will find many wonderful images of the result of a Strombolian eruption, however, what causes these eruptions?

The cause of a Strombolian eruption is generally accepted to be the result of the movement of a large gas bubble (or slug as it is sometimes called) up a volcanic conduit and subsequently bursting at the surface, hence throwing the hot material out in a spectacular fashion. There is some debate about the origin of these bubbles, whether they are the result of the coalescence of bubbles (the merging of bubbles) as they rise up the conduit from depth or whether they are the result of a collection of gases which create a foam (high proportion of gas to magma) at a point at depth beneath where the surface where this could occur.

At depth, however these bubbles are formed, the size is constrained by the pressure they are under. As the bubble rises, faster than the magma which it is in, it begins to grow in size and accelerate as a result, allowing a high enough velocity to eject material at the surface.Evidently a gas bubble of insufficient size will not result in a Strombolian eruption but can still burst at the surface and contribute to a phenomenon known as passive degassing (which I will refer to in a later pos)t.

Strombolian eruptions can occur on timescales of seconds to minutes to hours or more and are generally associated with less viscous (more runny) basaltic magamas at high temperatures of around or more than 1100 degrees celsius. I hope you have enjoyed my very brief overview of Strombolian eruptions, any questions please post and I will try to answer!

    Volcano Blog Logo

    RSS Feed

    Share this page

    Archives

    January 2021
    February 2020
    December 2019
    November 2019
    April 2019
    January 2019
    May 2018
    April 2018
    March 2018
    February 2018
    January 2018
    October 2017
    August 2017
    June 2017
    January 2017
    October 2016
    July 2016
    June 2016
    May 2016
    April 2016
    January 2016
    December 2015
    July 2015
    June 2015
    May 2015
    April 2015
    March 2015
    January 2015
    December 2014
    August 2014
    July 2014
    June 2014
    May 2014
    April 2014
    January 2014
    November 2013
    October 2013
    September 2013
    August 2013
    July 2013
    June 2013
    May 2013
    April 2013
    March 2013
    February 2013
    January 2013
    December 2012
    November 2012
    October 2012
    September 2012
    August 2012
    July 2012
    May 2012
    April 2012
    March 2012
    February 2012
    December 2011
    November 2011
    October 2011
    September 2011
    July 2011
    June 2011
    May 2011
    April 2011
    March 2011

An informative blog for anyone interested about all things volcano related!
  • Blog
  • About Me
  • Publications
  • Slug Calculator