On the morning of Friday 21st October 1966, eight-year-old Jeff Edwards set off for Pantglas Junior School with a spring in his step, already looking forward to the half-term that would start the following week.
It started as a normal day in the small mining village of Aberfan, but the catastrophic events that were about to unfold would change everyone’s lives forever. At 9:15am, more than 150,000 cubic metres of rain-soaked colliery waste came hurtling down the side of the spoil heap that towered above the school, engulfing everything in its path. The landslide claimed the lives of 116 children and 28 adults.
Jeff was one of four survivors in his class of 34 and was the last person in the school to be rescued from the rubble.
Just 20 miles from where the Aberfan disaster occurred, experts at Cardiff University are world-leaders in the prediction of earthquake-induced landslides. Dr Rob Parker, from the School of Earth and Ocean Sciences, is one of these experts and has been developing a statistical computer tool – known as ShakeSlide – that can provide a rapid assessment of landscapes after an earthquake and indicate where landslides are likely to occur.
A week before the 50th anniversary of the Aberfan disaster, Jeff (JE) and Rob (RP) met up at Ynysowen Primary School in Aberfan to talk about the significance of the disaster and how scientific research is transforming the way in which we understand landslides.
JE: What made you interested in landslides in the first instance?
RP: I’ve always found mountains fascinating. I’m a keen mountaineer and spend a lot of time climbing, so I’ve always been out there in the mountains. Landslides are probably one of the most dramatic processes that happen over a short period of time.
From early on at school I knew about the events at Aberfan and what happened there so both the physical process of why these things happen, and their impacts on society, interested me.
JE: How does the model that you’re developing differ from other models?
RP: We take the earthquake event as a whole and, over a very large area, we try and predict where landslides are likely to have happened, so it’s a broad area prediction. I work in a team of geomorphologists who study earth surface processes. Their natural interest is how a landscape behaves at a large scale. So the difference is rather than make predictions for specific locations – such as if a certain hillslope will fail or not – we want to know what the likelihood is over a large area.
JE: How accurate is the model that you’ve developed?
RP: In terms of predicting the precise locations of landslides, there is still a lot of uncertainty. There is uncertainty in the strength of the seismic shaking and the strength of the hillslope materials. What this means is that predicting the precise slopes that will fail is difficult, but predicting numbers of landslides across an area or along a valley can be done more accurately.
JE: Are there any practical examples you can give me where this model has been adopted?
RP: Last year when the Nepal earthquakes happened, we ran this model for the first time and we produced a prediction of the spatial pattern of landslides from that earthquake. We provided that model to the World Bank who were doing a lot of work in the post-disaster response to the earthquake. Together with satellite imagery it helped them guide the search for where landslides were likely to have occurred.
JE: What effect has climate change had on the number of landslides that have occurred?
RP: Climate change predictions suggest that we could see a 10% increase in the number ofbig rainfall events, which could lead to more landslides. We’ve done some work recently in the Appalachian Mountains in North Carolina, where we’ve essentially tested this theory and found that more rainfall events will not necessarily create more landslides.
We know that the landslide at Aberfan was triggered by rainfall, but the cause of the landslide was the tipping of mine waste up on the hillslope. If that mine waste hadn’t been tipped on the hillslope then the rainfall event would have happened, but we wouldn’t have had the landslide. Now in natural landscapes it is soil that accumulates on hillslopes, and accumulates slowly over time. In the Appalachian Mountains where we were working we found that the rainfall events were so frequent that the landscape isn’t actually producing soil quick enough to produce more landslides. So if we have more rainfall events, it doesn’t necessarily mean that there will be more landslides.
JE: Where do we see ourselves in ten years’ time?
RP: The availability of data sets is increasing. We’re getting 3D models of the Earth’s surface and records of where landslides have happened in the past. There’s a project called ‘Planet Labs’ that put hundreds of satellites into space over the last couple of years and they are in the process of imaging the entire Earth every single day.
With systems like that we’re going to have daily monitoring of physical processes on the Earth’s surface and that’s a really powerful tool for understanding when landslides happen and how they change with time. We’ll also have more and more powerful artificial intelligence machine learning algorithms that work with and process that data. So having that data and then being able to use it is only going to help our efforts to predict landslides.
JE: Obviously this year we’re commemorating the 50th anniversary of the Aberfan disaster, in which I was involved, so do you think the modelling that has been developed would have prevented the accident from happening?
RP: Looking back to Aberfan, perhaps one of the most interesting things to think about was that we knew at the time the dangers of landslides. Landslides from mine waste were actually quite common in the Valleys and I don’t think the problem there was so much the science, but the politics and getting people to act on that information.
As a physical scientist I seek to understand the physical process of how landslides happen and perhaps one of the biggest challenges we have is putting that information into the hands of policy makers who can then make informed decisions on that basis.
There was a big mine waste landslide that killed 128 people in China in 2008, so these things still happen around the world. A really important thing I like to remember about Aberfan is that it triggered more research into landslides and is part of the reason why the UK is a world-leader in landslide research.
JE: It is important that we remember this as an iconic event in terms of Wales and probably the world; that such a large loss of children, and the loss of adults as well, together with suffering of the community, is not forgotten.
Jeff Edwards joined other survivors, rescuers and journalists involved in the Aberfan disaster in speaking publicly at a September 2016 conference about their experiences. The conference was organised by our School of Journalism, Media and Cultural Studies to mark the 50th anniversary of the tragedy and explored media coverage of trauma.
Read the full interview
This is a shortened version of the full interview that features in the Winter 2016 issue of Challenge Cardiff, our research magazine.