Inside the mind of a volcano
Ahead of the opening of the new Volcanoes and Earthquakes gallery, Museum volcanologist Dr Chiara Maria Petrone talks about reading rocks and understanding eruptions.
The Museum's newly refurbished Volcanoes and Earthquakes gallery opens this Friday, 31 January.
Dr Petrone’s research has informed the science of the gallery since its inception. Her work involves trying to understand the behaviour of active volcanoes such as Popocatépetl in central Mexico, to help the people who live nearby deal with the threat of an eruption.
She describes a large part of her work as volcano ‘psychology’, attempting to get inside the 'mind' of a volcano and understand what processes control its 'moods'.
‘All the phenomena, the ash and lava, are external, you can see them,’ said Dr Petrone. ’But you don’t know what’s going on in the core of the volcano. I want to understand the core and see what the behaviour will be.’
By looking at rocks collected from the volcano, researchers can tell that over the past 14,000 years, Popocatépetl has experienced five huge eruptions.
Crystals in the volcanic rocks record changes that take place deep inside the volcano and cause different levels of activity. Dr Petrone then uses the crystals to see how long it took the volcano to move through each phase and to learn what might happen in the next big eruption.
Popocatépetl has been rumbling for centuries, but activity started to pick up in again 1994, raising fears of a big eruption, on the scale of the eruption of Vesuvius that buried Pompeii in AD 79. Popocatépetl last erupted this violently about 1,000 years ago.
On shaky ground
Popocatépetl regularly spews ash and gas, so the upper slopes of the volcano are off-limits to the public. To collect samples, Dr Petrone and her colleagues were allowed to climb higher, but it was a risky adventure.
‘It’s scary and it’s fascinating, it’s pure adrenaline,’ said Dr Petrone. ‘When you’re there you think ‘why am I here?’ then as soon as you get back you say, ‘I want to go there again’.’
When selecting the rocks to bring back, Dr Petrone also had an eye on the new gallery. At 4,600 metres up, she and Museum curator David Smith spotted a ‘bread-crust bomb’, the rather humble name for a huge chunk of lava with a cracked surface spat out by the volcano. ‘We saw that one and we thought ‘this will be lovely in the gallery’.’
It’s of great importance to Dr Petrone that Museum visitors understand not just the physical geology of natural disasters, but also the human impact of eruptions and earthquakes.
‘We try to make people aware, and hopefully they go home with the message that there is a way to cope with this, to act when an earthquake strikes or a volcano starts erupting,’ said Dr Petrone.
The Volcanoes and Earthquakes gallery is a free, permanent exhibition in the Red Zone.