When Will Kilauea Predicted to Erupt Again

Eruption of Mt. Pinatubo, Philippines, June 1991.

Can We Predict Eruptions?
past Peter Tyson In a word, yes. But that assertion, like saying we can predict the weather, bears significant caveats. Volcanologists can predict eruptions—if they accept a thorough understanding of a volcano's eruptive history, if they tin can install the proper instrumentation on a volcano well in advance of an eruption, and if they tin can continuously monitor and adequately interpret data coming from that equipment. Just even then, like their counterparts in meteorology, volcanologists can only offer probabilities that an outcome volition occur; they can never be certain how severe a predicted eruption will be or, for that thing, whether it will fifty-fifty break the surface.

Still, nether platonic conditions, volcanologists accept recently met with a great deal of success in foretelling eruptions. While they were caught off baby-sit by the exact timing and magnitude of the 1980 Mt. St. Helens eruption, for example, their timely warnings of an impending blow prompted the U.South. Woods Service to evacuate people from dangerous areas near the volcano. Though 57 people died in the eruption, perhaps 20,000 lives were saved, says Dr. William Rose, a volcanologist at Michigan Technological University. Similarly, a USGS SWAT squad that rushed to the Philippines' Mt. Pinatubo in the leap of 1991 successfully augured the June eruption, leading to evacuations that saved thousands if not tens of thousands of lives and millions of dollars worth of military equipment at the nearby Clark Air Force Base.

A Kilauea lava fountain spews from Puu Oo vent on March xiii, 1985.

Not surprisingly, volcanologists have had the most success at volcanoes that host their own observatories. In 1912, Thomas A. Jaggar, head of the Geology Department at the Massachusetts Constitute of Engineering science, founded the first volcano observatory in the United States on Kilauea. (In that location are now three others—in Menlo Park, California; Anchorage, Alaska; and Vancouver, Washington, about Mt. St. Helens.) Over the succeeding decades, researchers at the Hawaiian Volcano Observatory adult many of the techniques used today and tin now predict Kilauea'southward eruptions to a tee.

They know when and how Kilauea will erupt because it does and so frequently and predictably, and because after decades of intensive written report they know the volcano inside and out. Learning as much as possible near a volcano'south previous behavior is the essential beginning stride in anticipating future blows, just as knowing a career criminal's record can help indicate what he might do next. "There is no doubtfulness that the eruptive history of a volcano is the main cardinal for long-term prediction," says Dr. Yuri Doubik, a Russian volcanologist who has studied past eruptions on the Kamchatka Peninsula for 35 years. Such work entails laboriously picking through the physical remains of previous eruptions. And mapping such old lava flows, pyroclastic deposits, and other volcanic debris distributed around a crater tin reveal much almost the timing, blazon, direction, and magnitude of previous blows.

Close-up of a seismograph drum.

Satellite data can greatly assistance such mapping, and volcanologists are looking forrad to using images generated by the World Observing Arrangement afterward it is launched in 1999. The satellite's purpose is to study environmental ills such as global warming and depletion of the ozone layer, but it will also gather information of use to volcanologists, including gas concentrations in the atmosphere over volcanoes and images clear enough to reveal the fallout from former eruptions.

The Volcanologist's Toolkit

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When a volcano'due south eruptive history is known, researchers can more confidently turn to modern techniques to help them call the next eruption. The almost valuable among these, volcanologists agree, is monitoring a volcano's seismicity—the frequency and distribution of underlying earthquakes. Use of the seismologist's tool in volcanology has come a long manner since Frank Perret, i-time assistant to Thomas Edison, gleaned the frequency of the small shocks that continually shake Vesuvius's flanks past bitter down on the metallic frame of his bed, which was gear up in cement. Today sophisticated seismographs can register the magnitude, escalation, and epicenters of earthquakes that occur as magma moves below volcanoes. The more than seismographs technicians deploy on a volcano, the more complete the picture they become of the mountain'due south plumbing.

Tavurvur volcano erupts in the altitude as workers install a tiltmeter at Rabaul, Papua New Guinea, September 1994.

Seismic networks tin transmit data by radio 24 hours a twenty-four hours to figurer-equipped monitoring stations well out of harm's accomplish. This enables scientists to safely watch for changes in "nature's noise," equally one volcanologist labeled the geophysical status quo inside a volcano. Computer-based seismic information acquisition and analysis systems, which in essence constitute portable observatories, enabled the USGS Volcano Disaster Assistance Program's crisis-response squad to successfully predict the 1991 eruption of Mt. Pinatubo. Such "mobile observatories" themselves now constitute a major weapon in the prediction arsenal.

While seismicity is the workhorse, monitoring ground deformation is some other up-and-coming technique that allows iii-dimensional mapping of what's occurring hole-and-corner. Magma ascent from the depths ofttimes pushes the peel of a volcano up and out, like a airship filling with air. Sensitive tiltmeters and surveying instruments can measure and record the slightest changes, which help volcanologists determine, for case, roughly how deep a magma source is, how fast information technology is moving, and where on a volcano information technology might erupt. Such monitoring has helped scientists anticipate eruptions at Hawaii's Kilauea and Mauna Loa volcanoes, which deform in predictable means and at predictable rates.

A USGS team prepares to fly a gas-measuring flight at Montserrat, August 1995.

One drawback is that studying ground deformation has required scientists to climb volcanoes to take measurements—a perilous undertaking. Merely USGS volcanologists are now testing a prototype of a fully automated ground-deformation system. Flown aboard satellites or aircraft, the so-called "synthetic aperture radar" can automatically and continuously transmit information on a volcano'southward ground movements to remote observatories. Though it will not penetrate dense vegetation and is sensitive to moisture, the radar provides a resolution of less than an inch under ideal atmospheric condition. "It's a tremendous tool because it gives a complete map of ground movements, and we don't have to become into the field to go information technology," says Dr. Dan Dzurisin, a geologist with the USGS Volcano Hazards Programme (VHP) who is helping to perfect the new device. His colleague at the VHP, the volcanologist Dr. Robert Tilling, is equally optimistic: "We're confident that by the turn of the century, we'll accept such a system and at low enough toll that it can be practical easily everywhere in the world."

Measuring Vapors

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Such is the long-term hope as well for techniques to monitor volcanic gases. Magma deep hush-hush lies under enormous force per unit area, which keeps vapors dissolved. Just as magma rises toward the surface, the pressure eases and gases such as carbon dioxide and sulfur dioxide begin to bubble out of the liquid rock and into the air. Theoretically, changes in concentrations of CO _ii so _two emitted past a volcano can be used to predict eruptions, as can the escalating output of gases in full general. The USGS team that was sent to Pinatubo in the leap of 1991 successfully predicted the June eruption in part after watching And so _two levels shoot up to unprecedented levels of 16,500 tons per 24-hour interval.

Alaska's Spurr volcano blows its elevation on August 19, 1992.

Monitoring of volcanic gases got its start in the 1950s when enterprising Japanese researchers put beakers of potassium hydroxide, a potent, basic solution, on Honshu's Asama volcano, which was kickoff to show signs of erupting. As the highly acidic gases released past the crater seeped through holes in a crate roofing the beakers, they increasingly contradistinct the solution's composition in the months before a large eruption. Today, volcanologists use and so-called "Japanese boxes" routinely, though again they must cheque the beakers manually. To surmount this problem, Dr. Stanley Williams, an Arizona State University volcanologist who was near killed during a small but deadly eruption of Republic of colombia's Galeras volcano in 1993, is designing an electronic Japanese box that will automatically and continuously transmit data to a remote observatory. About the size of a briefcase, the battery-powered unit has tiny electrochemical sensors that create currents proportional to the amounts of various volcanic gases in the air.

Concurrently, Williams and others are working on infrared telescopes to monitor concentrations of gases escaping from volcanic vents. Williams'due south version is modeled afterward the correlation spectrometer, a device originally developed in the 1970s to monitor And so ₂ and other toxic gases from factory smokestacks. His prototype unit measures the amount of infrared light captivated past CO ₂ molecules, from which an guess of CO ₂ concentrations in the air can be made. Dr. Kenneth McGee, a volcanologist at the Cascades Volcano Observatory in Vancouver, Washington, is perfecting an infrared spectrometer that he says will detect still other volcanic gases that blot infrared light, including hydrochloric acid gas, carbon monoxide, methane, and water vapor.

Mt. St. Helens erupting, May eighteen, 1980.

Calling the Next Big 1

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While volcanologists feel confident that these always-improving technologies will enable them to predict when an eruption is almost to occur, they yet cannot reliably estimate an impending eruption'south size or exact nature. How big will the eruption be? Will it be explosive like Mt. St. Helens or effusive like Kilauea? Indeed, will information technology even open a vent in the surface? To be able to answer such questions, Tilling and USGS colleague Dr. Peter Lipman argued in a 1993 article in Nature for the demand to develop "rugged, reliable real-time systems" to mensurate changes not simply in seismicity, footing deformation, and gases, just besides in gravitational and electromagnetic fields—in short, equipment to read the gamut of signals given out by a restless volcano. "There's no magic bullet in predicting volcanic eruptions," says Dr. Charles Connor, a volcanologist at the Southwest Research Institute in San Antonia, Texas. "The key thing is to cross-correlate as many dissimilar observations as possible."

Tilling says volcanologists also demand to get a better handle on the basic mechanisms backside precursory signals, such as the long-period earthquakes that often precede eruptions. Dr. Bernard Chouet, a VHP volcano seismologist, says these quakes provide a "direct window" into the magmatic fluid moving most beneath a restless volcano. "These earthquakes are similar stress gauges that light up and reflect the pressurization going on below," he says. Careful monitoring of such natural gauges can help forecast eruptive activity. The USGS team that successfully predicted Pinatubo's burst did so in part by watching the build-up of long-menstruation quakes.

USGS Volcanologist Ken Yamashita surveys on the dome, Mt. St. Helens, March 1986.

The urgent need to ameliorate methods to call the next Big I holds especially true for large caldera-forming eruptions. These true globe-shakers explode with such Herculean forcefulness that they leave behind vast, basin-like depressions—calderas—that can stretch many miles across. The largest caldera-forming eruptions, which fortunately have not occurred in human history, brand the explosive eruption of Mt. St. Helens in 1980 seem like a firecracker. In the mid-1980s, three volcanic fields believed to hold the potential for one of these monumental cataclysm—California's Long Valley, Papua New Guinea'due south Rabaul, and Italian republic's Campi Flegrei—turned on well-nigh simultaneously, throwing the volcanological community into a bit of a frenzy. All three centers calmed down without further ado, though Rabaul erupted a decade later (run across Planning for Disaster).

Tilling, for one, is confident that such an apocalyptic smash will not come unheralded. "No volcano is going to all of a sudden produce ane of these humongous eruptions without giving a lot of signals," he says. "But what will those signals be?"Peter Tyson is Online Producer of NOVA. This slice was excerpted and updated from a feature article by Mr. Tyson that originally appeared in Technology Review (January 1996).
Photos: (1) USGS; (2) Jim D. Griggs; (3) C. Dan Miller; (iv) Andy Lockhart; (v) C. Gardner; (half-dozen) Robert McGimsey; (vii) Austin Post; (8) Steve Brantley. SWAT Team | Predict Eruptions? | Deadliest Volcanoes
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