Given the number of disasters in the world today we thought we would share some information from our book Supervolcano: The Catastrophic Event That Changed the Course of Human History (Could Yellowstone Be Next?) from authors Marie D. Jones and John Savino. Being informed and prepared about the possibilities that exist in this world are important lessons that everyone should learn. This excerpted section is from Chapter 9: The Lurking Mega-Disaster.
In the case of
As for deformation of the caldera, geologists most familiar with the Yellowstone region point out that while the caldera has been relatively dormant in terms of major volcanic activity for more than 70,000 years, it has been rising and falling for at least the past 15,000 years, at times more than 10 feet. In more recent times, between 1923 and 1975, the entire
Between 1997 and 2003, the northern part of the
A LONG VALLEY CALDERA
We now turn to the
In response to continuing seismic activity and uplift observed within the central portion of the
An ominous sign of unrest beneath the
In 2003, researchers reported the results of geodetic and gravity surveys conducted in the
A EARTHQUAKES AS A TRIGGER?
In their Summary of
Certainly the most remarkable and energetic event in the caldera during 1992 was the abrupt surge in local seismicity that began immediately following the June 28, M=7.3 Landers earthquake, which was located in southern
Signals associated with transient periods of deformation near the western boundary, and within the caldera, also accompanied the triggered seismicity.
While the evidence for remote triggering of unrest at volcanic calderas by large earthquakes is reasonably convincing, what’s the possibility for an earthquake occurring in southern
Map of the
The lack of experience that scientists have when it comes to recognizing the signs or signals coming from a volcanic system or caldera on the verge of a supereruption poses a major challenge to successful forecasting. Recall that the last supereruption, Taupo, occurred about 26,000 years ago. In addition, the last VEI 7 eruption, Tambora, occurred in 1815, well before instrumental records became available. Thus, volcanologists will be hard pressed to not only identify a signal from an eruption that could be imminent, but recognize a bona fide signal (for example, volcanic tremor) for a VEI 7 or 8 eruption, as opposed to a 4 or 5.
In a recent paper published in the Philosophical Transactions of the Royal Society, scientists from the USGS and the
With limited experience monitoring and responding to large-scale volcanic crises, society cannot expect a 100 percent success rate at avoiding future volcanic catastrophes. We can, however, make sure that we learn from the next VEI 6 or 7 eruption, by recording a full spectrum of signals emitted prior to eruption. At present, only a small fraction of Earth’s high-threat volcanoes is monitored in a manner that would provide a useful history of the run-up to a volcanic disaster. If we are to reduce the risk from future large eruptions, we will need to do better.