The Yellowstone caldera is labelled a supervolcano due to its ability to inflict devastation on a global level. Pinned between the states of Wyoming, Montana and Idaho, the volcano is constantly monitored by the USGS (United States Geological Survey) for signs that a supereruption is on its way. In 2012, USGS scientist Greg Vaughan, together with colleagues from the Yellowstone National Park, used satellite-based thermal infrared (TIR) remote sensing data from two NASA satellites – MODIS and ASTER.
They used the probes to measure surface heat below Yellowstone National Park to monitor changes and identify any “abnormal anomalies”.
The research, which was published on the USGS website, revealed: “Vaughan used nighttime MODIS data to establish background thermal patterns and to quantify how much temperatures would have to change to be detectable with modern spaceborne techniques.
“Most natural thermal changes at Yellowstone within the past decade are around the detection limits of the technique, providing hope for future monitoring during more active periods.
“The ASTER data cover smaller areas with greater spatial detail (about 90 meters per pixel).
“Vaughan was able to use ASTER to create maps showing regions where abnormal amounts of heat are released, called thermal anomalies, and also to estimate surface temperatures and other aspects of heat flow at Yellowstone.”
The study went on to reveal the areas with the highest “abnormalities” in the park.
It continued: “Within the time frame of the study, the thermal areas with the highest temperatures and the highest heat flow were the Sulfur Hills near Yellowstone Lake and the Grand Prismatic Spring in Midway Geyser Basin.
“The ASTER-based estimate for how much geothermal heat was radiating away from all of Yellowstone’s thermal areas, was 1,970 megawatts, which is comparable to measurements made with land-based techniques that take much more time to acquire than satellite measurements.
“This work provides a basis for future use of satellites to measure and monitor changes in geothermal areas around the world that are well below magmatic temperatures and have proven difficult to study with satellite-based techniques.”
Yesterday, a magnitude 3.1 earthquake was recorded just 100 miles from Yellowstone National Park in Manhattan, Montana.
Though the tremors were small, they will still be of interest to scientists due to the high possibility of a swarm, which can see hundreds of small earthquakes in a short period of time.
USGS’s website explains: “Since 1973, there have been over 48,000 earthquakes located in the Yellowstone region.
“Over 99% of those earthquakes are magnitude 2 or below and are not felt by anyone.
“Earthquake swarms (earthquakes that cluster in time and space) account for about 50 percent of the total seismicity in Yellowstone and can occur anywhere in the Yellowstone region, but they are most common in the east-west band of seismicity between Hebgen Lake and the Norris Geyser Basin.
“Most swarms are small, containing 10-20 earthquakes, and short, lasting for one to two days.
“However, large swarms that can contain 1,000’s of earthquakes and last for months do occur on occasion.”
Earthquake swarms pose a threat as they can trigger a volcanic eruption, though scientists are unsure exactly how.
They believe the volcanic activity possibly occurs in response to a change in the local pressure surrounding the magma reservoir system as a consequence of severe ground shaking caused by the earthquake.