Earlier this spring, you probably saw some lurid television promotions about “a true story that hasn’t happened yet.” It was all part of the marketing promotion for a BBC Science and Discovery Channel docudrama called “Super-Volcano,” followed by the documentary, “Supervolcano: The Truth About Yellowstone.” For all of its doomsday atmosphere, “SuperVolcano” may just be the best thing that’s happened to Yellowstone – free publicity and lots of it. “We’re getting great public interest in the geology and geothermal features of the park,” said Hank Hesler, park geologist. “Public reaction has been very positive, because people want to learn more.”
All of Yellowstone’s geysers, hot springs, mud pots and other geothermal features are directly related to a vast magma chamber, deep under the park. The heat from that magma chamber drives all of Yellowstone’s geothermal features, Hesler said. Periodically, about every 600,000 years or so, said Hesler, all that energy in the magma chamber breaks loose in a “supervolcano.” Past eruptions were 2.1 million years ago, 1.2 million years ago and 640,000 years ago. The three eruptions, respectively, were about 6,000, 700 and 2,500 times larger than the May 18, 1980 eruption of Mt. St. Helens in Washington State.
The program aired last March in the British Isles and in April in the United States.
“This is a dynamic environment,” said Hesler, “and it is changing all the time. As often as I look at our geothermal features, I’m always seeing something new.” That was proved once again in late May, when the Steamboat Geyser – Yellowstone’s tallest and most unpredictable geyser – erupted for the first time since 2003. According to park records, the geyser has erupted more times in the past five years than it has since the 1980s. There’s nothing static about Yellowstone’s geothermal features, Hesler said. As a result, the concept of “normal” activity is broad, rather than narrow, he said.
Shortly after the showing of “SuperVolcano,” the U.S. Geological Survey (USGS) released the first-ever comprehensive and systematic review of the 169 U.S. volcanoes. USGS also established a framework for a National Volcano Early Warning System (NVEWS) which calls for a 24/7 Volcano Watch Office, plus enhanced instrumentation and monitoring at targeted volcanoes – including Yellowstone.
USGS identified 37 volcanoes in the Very High threat group and mentions an additional 21 under-monitored volcanoes. Yellowstone is one of the 21 under-monitored volcanoes in the High threat group. USGS officials emphasized that this does not mean that the geologic conditions at Yellowstone have changed. The activity at Yellowstone remains consistent with historic levels.
“We’re getting six more GPS, real-time monitoring stations,” said Hesler. That will double the number of year-round monitoring stations in the park. That’s supplemented every two years when USGS brings in a bunch of portable monitors for a few days. In addition, said Hesler, a satellite with radar imaging technology is scheduled once a year to scan the park to see whether it can detect up-or-down surface deformations – an indicator that something is happening.
About the show
“The show tries to envision what would happen if we had another super-eruption like we had 2.1 million years ago,” said Jake Lowenstern, director of the Yellowstone Volcano Observatory (volcanoes.usgs.gov/ yvo/). The producers, writers and scientists behind the show talked to Lowenstern and many other scientists who study Yellow-stone’s geological features.
“I have to say that in all the important respects, they got the details right,” Lowenstern said.
According to the scientific speculation in the docudrama, a super-eruption would:
· Block highways with cars as millions flee the unfolding disaster.
· Kill hundreds of thousands as the ash swamps towns and cities.
· Knock out modern communications.
· Form sulphuric acid droplets in the atmosphere, blocking out sunlight, and causing global temperatures to plummet and devastate crops.
That said, Lowenstern emphasized that a super-eruption beneath Yellowstone “is not likely to occur any time soon, or maybe ever.” He readily acknowledged that all prior supervolcano eruptions around the world took place well beyond historical experience, so geologists have had zero experience studying how a supervolcano gears up for a super-eruption. “We are getting pretty good at forecasting eruptions when volcanoes are restless,” he said. “So far, there is no sign of that with Yellowstone.”
There are several extinct supervolcano sites around the world, Lowenstern said – the nearest is in the San Juan mountains of Colorado, where a super-eruption blew 20 million years ago, near the mining town of Creede. That supervolcano site hasn’t made a peep since then, he said. “My recommendation,” said Lowenstern, “is to relax and take this program as an educational opportunity.”
That’s how Yellowstone National Park is treating it. Linda Young, one of the three top directors of the park’s Division of Interpretation, is working on display exhibits about Yellowstone’s volcanic past, which will appear in the Canyon Visitor Education Center next year. The park is also working to replace an antiquated visitor center near Old Faithful, with a new and much bigger visitor center focused on the park’s hydro-thermal features. The new center is scheduled to open in 2008.
“Last September, after most of our visitors were gone, we installed a number of interpretive displays along the Mud Volcano Trail,” said Young. Located five miles north of Fishing Bridge Junction, Mud Volcano Trail is one of the park’s most exotic, dynamic and even odd geothermal features, said Young.
“We have a geyser that erupts out of a cave, and a hot spring pool that is inky black and highly acidic,” said Young.
All in all, said Young and Hesler, public reaction to the supervolcano publicity has not been panicky or ‘doom and gloom.’ “Actually, there’s been little public feedback, compared to bison and grizzly management issues,” said Young.
Normal volcanoes are formed by a column of magma (molten rock) rising from deep within the Earth, erupting on the surface, and hardening in layers down the sides to form cone-shaped mountains.There are thousands of these normal volcanoes throughout the world. Around 50 erupt every year, but supervolcanoes are very different.
The term “supervolcano” implies an eruption of magnitude 8 on the Volcano Explosivity Index, indicating an eruption of more than 1,000 cubic kilometers (250 cubic miles) of magma.
Steamboat, World’s Tallest Active Geyser, Erupts
Visitors to Yellowstone National Park’s Norris Geyser Basin were awarded with a unique experience when Steamboat, the world’s tallest active geyser, erupted after an almost two-year hiatus. Eruptions of Steamboat Geyser are entirely unpredictable.
On May 23, 2005, at approximately 2:40 p.m., a National Park Service employee reported that Steamboat Geyser was erupting. Steamboat Geyser rarely erupts in its major phase. More commonly, Steamboat ejects water in frequent bursts of 10-40 feet. During a major eruption, Steamboat can reach heights of over 300 feet, showering viewers with mineral-rich waters; this most recent eruption expelled approximately 11,500 gallons of water. For hours following its rare 3-40 minute major eruptions (water phase), Steamboat thunders with powerful jets of steam; this steam phase can continue as long as 12 hours after the water cessation.
Steamboat’s intervals vary from three days to fifty years (Steamboat was dormant from 1911 to 1961). In recent years, Steamboat has erupted in 1989 (3 times), 1990 (1 time), 1991 (1 time), 2000 (1 time), 2002 (2 times) and 2003 (3 times).