One of the main reasons that tourists now visit Montserrat, only a 15-minutes flight away from Antigua is to see the Soufrière Hills Volcano that reawakened 20 years ago leaving two-thirds of the island uninhabitable. In addition to the Soufrière Hills Volcano, there are actually three other volcanoes on Montserrat, the Silver Hill, the Centre Hills and the South Soufrière Hills. All three volcanic systems are extinct.
Montserrat: Map of the island outlining the volcanic areas. Photo: ©Dickinson College.
While the Soufrière Hills Volcano will now always be a concern for the 5,000+ people who live on the tiny Caribbean island (39 square miles), it has been relatively quiet in recent years. Also, the Government of Montserrat recently tested the waters and allowed a few tour groups to enter the southern Exclusion Zone to see the former capital Plymouth now mostly buried under volcanic ash and described by many as a modern day Pompeii. Below we conduct a brief questions and answers session with the Montserrat Volcano Observatory the government organisation responsible for monitoring activity the Soufrière Hills Volcano.
1. What was the height of the volcano pre-eruption and how high is it now?
The tallest peak in Montserrat before the eruption was Chances Peaks at 914m (3000ft). The highest point on Montserrat now is a dome of volcanic lava. The top of the dome is currently approximately 1084m (3556ft) above sea level, so about 170m higher than Chance’s Peak.
2. What caused the Soufrière Hills Volcano to reawaken from its slumber 20 years ago?
Volcanoes erupt when hot buoyant magma rise to the surface from deeper within the earth’s crust. This is generally the reason for the current eruption.
3. What happened after the Soufrière Hills Volcano began erupting?
The Soufriere Hills Volcano began to erupt on July 18th, 1995. It is the most recent in the Caribbean and the longest to have occurred in the region in recorded history. Up to this time (2015) the eruption has had 5 phases of lava extrusion and 5 pauses. During active phases, the volcano creates andesite domes that eventually become unstable and collapse, causing pyroclastic flows and surges. It also generates very large explosions with ash columns that can reach more than 15 km (50,000 ft.) into the atmosphere. Explosions have also generated large pyroclastic flows that have moved more than 2 km over the sea.
The former capital Plymouth and many southern and eastern villages have been destroyed by pyroclastic flows and surges over the course of the eruption, and some areas have been subsequently buried by mud flows. On 25 June 1997, at least 19 people were killed in areas to the north of the volcano, when pyroclastic surges swept through the village of Streatham and other areas. The fatalities occurred inside the exclusion at the time. While the eruption has been very destructive to Montserrat’s landscape, infrastructure and economy, all residents and businesses have relocated to safety in the north of the island where people continue to live and work.
4. How much volcanic ash, mud and rocks covered Plymouth, Belham Valley, etc.?
The total amount of lava erupted in the whole eruption is more than 1 cubic kilometre (10^9 or 1 billion cubic metres), but the amount of material found in the valleys surrounding the volcano varies considerably. For example, the lower reaches of the Belham Valley contain as much as 15-20 m of primarily lahar deposits while a similar amount of pyroclastic flow and lahar deposits are found in Plymouth.
In areas closer to the lava dome, such as the top of the White River valley, on the southwest flank, more than 100 m of debris deposited by pyroclastic flows filled the upper reaches of the valley during a short two month period of activity in October and November 2009. In February 2010, a large partial dome collapse removed 50 million cubic metres from the dome (which measured 245 million cubic metres at the time) that was largely deposited by pyroclastic flows along the coast northeast of the volcano. These deposits covered more than 10 sq. km, created 1 sq. km of new land and buried the old W.H. Bramble Airport with more than 15 m of debris.
5. Where is the furthest point from the Soufrière Hills Volcano that volcanic ash has reached?
During activity, ash can fall anywhere across the island, though it is dependent on the wind direction. However, much of the ash erupted from the Soufriere Hills Volcano never falls on Montserrat. It is carried out to sea and across neighbouring islands by the wind. Following the dome collapse on 11 February 2010, ash was blown to the southeast and was recorded as far away as NW Dominica.
6. What is the level of the volcanic activity today?
At present, the level of volcanic activity is very low. There has been no surface activity such as lava extrusion or explosions since February 2010. The volcano is still active however, and it is continually monitored for signs of increasing activity.
7. How close can people get to the Soufrière Hills Volcano today?
People are allowed to view the volcano from a safe distance of a few miles. The Hazard Level System in Montserrat controls activity around the volcano, letting people know the level of risk in various areas and the amount of access allowed. Montserrat Volcano Observatory staff occasionally go closer to the volcano in the course of monitoring the eruption.
So will you be visiting Montserrat to see Plymouth, now a modern day Pompeii? It is a fantastic destination for professional or amateur volcanologists and really anyone who wants to see how an island is transformed after a major volcanic eruption. Montserrat will observe and commemorate the 20-year anniversary of the Soufrière Hills Volcano erupting on 18th July 2015. With that, find a tour guide to show you around Montserrat via VisitMontserrat.com. No doubt they will recommend a visit to the Montserrat Volcano Observatory in Salem to learn more about the Soufrière Hills Volcano. Also to other volcano viewing points on the island including Belham Valley, Garibaldi Hill and Jack Boy Hill. Helicopter tours of the Soufrière Hills Volcano can also be arranged from Antigua.
Top photo: Montserrat: Calmer view of the Soufrière Hills Volcano. Photo: ©Ursula Petula Barzey.