Kingstown – Linking geothermal energy exploration to the eruption of La Soufriere is like expecting a skin-deep injection to puncture one’s heart, geologist Professor Richard Robertson has said in response to questions about whether the drilling on the volcano’s slopes last year could have resulted in the current eruptions.
“In the case of geothermal, both at this volcano and other volcanoes, there is no indication scientifically that they should affect each other in terms of getting a volcano going. And certainly, in this case, we don’t think it did,” he said.
In 2019, the government dug three wells as part of the geothermal energy project, but each failed to produce the required permeability. Then, in December 2020, after almost 42 years of inactivity, La Soufriere began erupting effusively, then exploded on April 9 – an eruption that continues to date.
In one of his daily updates on the state-owned NBC Radio, Robertson was asked if there was any link between the geothermal drilling and the eruption of the volcano.
“I think even before the Soufriere was active we were being asked about it and I have made the analogy that the geothermal – I look at it in the context of the human body and the source for the volcanism – is like deep beneath the surface of your body, sort of your heart, right inside the core of your structure while the way in which you were tapping into geothermal is really tapping into the hot rocks that is heating fluids that is above that.
“So it is a bit like sticking a needle into your skin and thinking that that needle sticking into your skin is somehow going to touch your heart. That’s how the dimensions are,” he explained.
Robertson further explained that during the geothermal activity, the deepest well “went down less than 3 kilometres (1.86 miles), 3 000 metres (9 842 feet)”, while “the thing” that is driving the eruptions is at least 10 kilometres (6 miles) beneath the surface of the earth.
“Geothermal has been successfully applied in areas that have ongoing volcanic eruptions,” he added, naming Iceland as an example.
“Icelandic volcanoes erupt all the time, you have seen that . . . and they have serious geothermal operations and they don’t affect each other. Because they just operate at different levels. They operate at different depths and they interact with different kinds of materials than the magma.
“The magma chamber is deep beneath the surface and it’s operating based on time scales that have to do with plate tectonics, that have to do with the movement of tectonic plates on a larger scale than the geothermal is operating.
“I can’t see scientifically how it could have affected it. It’s not like you are drilling into the magma chamber. If you were doing that, I suggest to you that the drill would have been burnt and destroyed long before it gets anywhere close to the chamber. It would have been destroyed at the hot rock stage, not even the chamber,” the geologist added.
Robertson said that he understood the concern that there could be a connection. But he said that “there are lots of things that happen together that are coincidental and not causative”. (CMC)
