Geothermal drilling not the cause of eruption: scientist
Drilling for geothermal energy would not have occurred anywhere near the depths of the magma chamber, and there is no scientific reason that it would have affected the volcano.
Geologist Professor Richard Robertson addressed this issue once more yesterday morning, April 22, while doing his daily updates on NBC radio.
The question was posed by the public whether St Vincent’s exploratory drilling for geothermal energy in 2019 at Bamboo Range would have affected the volcano which is now erupting explosively.
“It’s amazing how much that comes up and it’s amazing how much both myself and my colleagues at seismic have addressed it. I think even before the Soufrière was active, we were being asked about it,” the Professor responded.
“…The source for the vulcanism is deep beneath the surface of your body, [as an analogy] sort of you think 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 rock that is heating fluids that is above that,” he explained.
“It’s 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.”
What is driving the current eruption is at least 10km below the surface, but for the geothermal, “the deepest well probably went down to about less than three kilometers, (or) 3000m.”
“…what it was tapping was not the magma. It wasn’t getting anywhere close to any magma,” he said.
“What it was tapping into was the hot rock,” which extends for several kilometers out of the chamber, “because the magma would have heated the surrounding rock and then that heated rock would then have heated circulating fluids.” This water would then be used to generate energy.
“The magma chamber is deep beneath the surface and is 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 in,” the geologist explained.
“I can’t see scientifically how it would have affected it, it’s not like you were 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 get anywhere close to the chamber.”
Professor Robertson noted that he could understand how persons would think this way because of the circumstances, “but there are lots of things that happened together that are coincidental and not causative.”