Scientists found the growing thermal area, which is currently around eight acres in size, by observing the quantity of dead vegetation in the vicinity. The troubling phenomenon has been labelled a “tree kill zone” as the ground is warmer than its surroundings, causing trees to die off. While scientists have only just confirmed its existence, the United State Geological Survey (USGS) estimates it’s been forming over the last 20 or so years.
In a new post for the USGS weekly Caldera Chronicles, scientists have revealed the existence of a new thermal area near Tern Lake.
These areas are home to thermal features such as hot springs and geysers – of which there are more than 10,000 spanning the length and breadth of the park.
Scientists have noticed a growing thermal patch between the established Tern Lake Thermal Area and West Tern Lake – and trees don’t appear able to survive it over the last few years.
A look through the imagery going back to the 1990s confirmed what they suspected – a growing bright patch in the middle of the forest, signalling warmth beneath the surface.
The USGS said: “Analysis of a Landsat-8 nighttime thermal infrared image acquired in April 2017 revealed an unexpected warm area between West Tern Lake and the previously mapped Tern Lake thermal area.
“This mysterious patch of bright pixels in the thermal infrared image did not match any previously mapped thermal areas.
“The most recent image of the Tern Lake region, from 2017, reveals a large area of dead trees and bright soil, rather like a thermal area.
“From all these satellite and aerial images, we conclude that a new thermal area has emerged in the past 20 years!”
However, contrary to appearances, the phenomenon is allegedly no cause for concern.
Experts claim that it is simply in line with what is expected in the Yellowstone area.
Yellowstone volcano’s caldera has risen up to 70cm in parts, according to USGS scientists who revealed they will continue to monitor it.
Speaking at a public lecture in Menlo Park, California in 2014, scientist Jacob Lowenstein revealed how the ground rise from Yellowstone was measured.
He said: “So the really remarkable thing about Yellowstone is that it moves up and down.
“The ground surface is unstable and over time it moves.
“Bob Smith was one of the parties that came in and re-surveyed a series of roads that hadn’t been surveyed since the Twenties.
“Dan Dzurisin also worked on this topic, he’s from the Cascades Volcano Observatory.
“Bob and his colleagues re-occupied the benchmarks that were done previously in Yellowstone.
“And he made a contour map that shows the number of millimetres that the area has gone up.”
“Most of the activity is going on in the caldera and the uplift is about 700mm in between two areas we call the resurgent domes.
“So it’s 700mm, 70 cm, which is about two feet and so that has happened in 50 years.
“This is a remarkable observation and something we have been tracking ever since – we’re trying to understand it.”