Welcome to montserratvolcano.org

 

 

This website is neither created nor owned by the residents of Montserrat but I hope that they will treat it as their property and help me develop it in whatever way they wish. Montserrat has been greatly troubled and partly laid waste by an erupting volcano for more than a decade. This was peaceful (apart from occasional relatively small explosions) from early 2007 until just before the date when I was planning to publish the website (29 July 2008). During the previous night major new eruptive activity took place and the circumstances surrounding this are detailed on the MVO website, together with photos of both the 28 July deposits and their Gages Vent source, at http://www.flickr.com/photos/mvo/. Since then lava extrusion started, stopped and started again at Gages Vent. In addition, another vent opened on the NW side of the lava dome in early September 2008 and this produced some violent explosions (without any warning) on 3 January 2009. Subsequently, the eruption paused again and the report of the 12th meeting of the international Scientific Advisory Committee (SAC) at MVO in March 2009 suggested that further short (few weeks) periods of lava extrusion and sudden explosions might occur during the coming year. As the main extrusion vent had moved in December 2008 towards its "traditional" site atop the dome, the SAC considered that the risk had increased slightly of a future major dome collapse and/or explosion sending pyroclastic flows (PFs) into the Upper Belham Valley (via Tyer's Ghaut) and thus continuing to enlarge and smooth the growing debris fan there. Such debris fans make it easier for future PFs perhaps to reach the Lower Belham Valley -- a process seen earlier in the eruption, during the burial of Plymouth by PFs.

 

The volcano was clearly listening intently to the SAC in March 2009 and has since done precisely what they forecast! It remained peaceful through the summer and allowed Montserratians to concentrate on the excitement and outcome of a General Election in September. Then it re-awakened abruptly on 4 October, after giving only about three days of warnings (increased earthquake numbers and an abrupt drop in the amounts of SO2 emitted from the volcano). Explosions between 4 and 7 October sent ash plumes up to about 6000 metres. By 9 October a new lava dome could be seen growing on the summit of the previous one (the one that has failed to collapse wholesale since it formed in 2006-7, despite earlier “near certain” forecasts that it would do so). Between early October 2009 and mid-February 2010 the volcano really showed its teeth. Rapid lava extrusion increased both the height and volume of the dome to the largest yet seen. Several very large explosions, with little or no obvious warning, sent PFs into new places, such as the seaward ends of Aymers and Gingoes Ghauts.  On 10 December a PF reached to below the western end of Lees village and triggered an NDPRAC decision to evacuate Zone B (see MVO website for the acronyms etc). On 8 January a PF generated by another very large and unannounced explosion travelled about 6 km down the Belham Valley – further than ever before during the long eruption and reaching to within about 500 m (as flown by a terrified chicken!) of houses occupied until shortly before the evacuation.

 

After very rapid further growth in early February, about 20% of the dome collapsed (accompanied by huge explosions), feeding about 40-50 m3 of material ranging from fine ash to house-sized blocks in to a series of PFs that inundated the entire NE slopes of the volcano. Some of the PF material also came down the Belham Valley, to the NW, and stopped only about 1 km away from the evacuated areas. Since then the volcano has reverted rapidly to its quiet-as-a-mouse behaviour and the residents have returned to their extremely dusty homes around the Lower Belham Valley. But for how long?

 

The eruption of Merapi, Indonesia, in 2010 has produced one of the few features of the long Montserrat eruption that has been lacking. This is a detailed digital photographic record of exactly what happened to buildings, livestock and people on 25 June 1997. The Merapi eruption began when the world's press were nearby, drawn by a terrible tsunami. Top photographers therefore rushed to this volcano and dozens of both top-quality and very harrowing photos have appeared on the internet. I've therefore taken the opportunity to add another topic to this website, containing some of the Merapi images most relevant to Montserrat. This relevance will only cease when there is no longer any threat of a pyroclastic surge overrunning the Salem-Olveston area.

 

There is of course an excellent and comprehensive, recently redesigned, official Montserrat Volcano Observatory (MVO) website [http://www.mvo.ms/] and you may think; “Why another one?” Just take a quick look at this one and decide for yourself if it is helpful to you. Whatever you decide, please let me know. This website is designed to be read with Wikipedia [http://en.wikipedia.org/wiki/Main_Page] open at the same time on your computer. Whenever you find a word or phrase that needs more explanation, just type it into the search line of Wikipedia and read more about it there. For those of you who would like to see an overall account of the eruption at a more detailed and "scientific" level than this site, but less than MVO or the research literature, try Richard Roscoe.

 

I start with a short account of the most obvious thing – why is there a volcano on Montserrat? Most of you “know” the answer to this question but are split between two entirely different viewpoints. For some, it is part of God’s creation and that’s all there is to it. Others prefer the explanations worked out by scientists and this is the approach that I shall take here. Nevertheless, it’s essential to say at the outset that only this first theme will be seen differently by different residents.  The following themes will be designed to be equally useful to all of you, by discussing practical matters about the eruption and its threats. Even strongly religious people may find that the following material about volcanic magma and lava domes is interesting.

 

PLEASE NOTE: AS OF 2 JUNE 2013, THERE ARE 25 BROKEN HYPERLINKS AMONGST THE MANY ON THIS SITE. WHEN YOU FIND SUCH A BROKEN LINK, PLEASE CONTACT ME AT bobnthompson@gmail.com

 

 

Soufrière Hills from Jack Boy Hill (2007)

Bob Thompson

Soufrière Hills from St George's Hill (2007)

Steph Flude

 

 

These 2010 photos explain why people are not now allowed to visit the ruins of Plymouth -- the "Modern Pompeii"

 

Pyroclastic flow entering Plymouth ruins, Jan 2010 (Martin Rietze).

Pyroclastic flow entering the sea at Plymouth, Feb 2010 (Thorsten Boeckel)

 

 

 

The helicopter engine stays running when MVO scientists are working so close to a volcanic lava dome that is incandescent inside. Pyiko Williams always forgets the dress code!

Greg Scott

This lava dome has been known to unleash multi-megaton explosions without any warning. Graham Ryder must need to wash his flowing mane after such visits to the mountain top!

Greg Scott

 

 

MVO view of the volcano in mid-March 2011. The 2010 dome collapse scar is obvious from the fumaroles peppering its walls. Obviously the possibility of a similar-sized collapse all passing down the Belham Valley would be extremely small; St George's Hill protects Salem.

Helicopter close-up of the collapse scar. Note masses of fumaroles all over the floor.  Greg Scott

 

 

Another amazingly clear view taken by Tradewinds in February 2011

John and Henry on the tiny summit of Gages Mt, March 2011. If the lava dome collapses now, both  will hit the sea base-over-apex.

 

 

CONTENTS

1.  General introduction: the science view, page 1.  edited 12 APRIL 2010

                                                                         page 2.  expanded 9 APRIL 2010

2.  Introduction to pyroclastic flows and surges, page 1.  expanded 13 APRIL 2010

                                                                                 page 2.  expanded 13 APRIL 2010

                                                                                 page 3.  expanded 14 APRIL 2010

3.  Mathematical modelling of pyroclastic flows: the E' VIVO! website.

4.  Blast, heat, debris and dust: how do pyroclastic surges damage buildings? page 1.  edited 15 APRIL 2010

                                                                                                                                      page 2.  edited 15 APRIL 2010

                                                                                                                                      page 3.  edited 27 NOVEMBER 2010

5.  Blast, burns, asphyxia and hypoxia: how do pyroclastic surges damage humans?

6.  How pyroclastic surges sometimes “bounce” landwards when they reach the sea.  expanded 16 APRIL 2010

7.  A surge’s dangerous offspring: secondary pyroclastic flows.  edited 15 APRIL 2010

8.  Say no to maps? How to communicate volcanic hazard effectively on Montserrat, page 1.  edited 17 APRIL 2010

                                                                                                                                                page 2.  expanded 17 APRIL 2010

9.  Who trusts who and why? Risk communication during the Montserrat volcanic eruption, page 1.  edited 17 APRIL 2010

                                                                                                                                                          page 2.  edited 17 APRIL 2010

10.  Frogs in saucepans, and cats and mice: key danger characteristics of the Montserrat eruption, page 1.

                                                                                                                                                                          page 2.   expanded 19 FEBRUARY 2011

11.  Montserrat at war: living beside a dangerous volcano ADDED 29 APRIL 2010

12.  Can geophysical modelling predict the end of the Soufrière eruption?  

13.  Comments and discussions.  If you wish to make a point, please email me at bobnthompson@gmail.com  and I'll answer and also put it on a discussion page for you, if you wish.

14.  Notes from a very small island for would-be visitors  updated 8 NOVEMBER 2010

15.  Where next for Montserrat? page 1. ADDED 9 JUNE 2010

                                                       page 2. ADDED 9 JUNE 2010, expanded 17 MARCH 2011 and 31 May 2013

16.  Merapi 2010: pyroclastic surges wreck villages in front of the world's press.   page 1 ADDED 8 NOVEMBER 2010, updated 30 DECEMBER 2010

                                                                                                                                           page 2 ADDED 8 NOVEMBER 2010, updated 19 FEBRUARY 2011

                                                                                                                                           page 3 ADDED 8 NOVEMBER 2010, updated 19 FEBRUARY 2011

17.  Housekeeping.

 

Last updated 26 February 2014