[Updated 16-Jun-2011]

WOVOdat, a new global volcanic database, will put critical information at scientists' fingertips in times of volcanic crisis.

Suppose your local volcano starts rumbling. Most times it will be nothing, and the volcano will harmlessly settle down again. In about ten percent of cases, unrest foreshadows an eruption, months, days, or even just hours away. Some volcanoes threaten dense population centres, so predicting eruptions is grave work. Decisions must be informed, but also quick.

Predicting a volcanic eruption is a bit like gambling

These decisions can be like gambling. Eruptions are not simple: volcanic precursor symptoms have many possible meanings and sometimes not even experts know what will happen. That is why the boundary between success and failure is very thin.

You know that a volcano has already inflated by two metres. Will it lead to eruption? Do you wait until four metres? What if it erupts after just another half metre? These difficult judgements mean a high risk of false alarms, or, much worse, failure to predict devastating eruptions.

It would be great if volcanologists could have instant access to old records, to compare present unrest with what has been seen before for that volcano. Even better, a volcanologist could compare present unrest with that from all similar volcanoes. Searching in a library takes too long. So Professor Chris Newhall (current Head of the Volcano Group for EOS) and Dr. Antonius Ratdomopurbo (Head of WOVOdat project at EOS) are working tirelessly to establish a public database of historical volcanic unrest and its outcomes.

WOVOdat – a public database of volcano monitoring information

WOVOdat, as the project is called, is a web-searchable database of volcanic data. WOVO is the World Organisation of Volcano Observatories. When fully operational, WOVOdat will combine the total collective volcano experience since records began, with all modern and future volcano monitoring data recorded from all of the Earth’s monitored volcanoes. Observatories will be the main data sources and the main users, but it will be freely open to students, citizens, officials, and all others (Fig. 1).

Figure 1. WOVOdat data flow.

A generation ago, this idea would have been nearly impossible. Few volcanoes were monitored compared to now, and not continuously. Information was sparse, and also difficult to collect and share. The only computers capable of handling data at that time were mainframes, and their use was clunky and difficult. So too was the then-rudimentary internet.

Today, all this has changed. Wireless instruments make it easy to continuously record information about many volcanoes; these instruments can also be cheaply and safely replaced if damaged by the volcano. Today, many volcanoes are monitored continuously, producing mountains of data. Modern computers and the World Wide Web make that easy to share and centralise.

WOVOdat will be searchable like any database. Typical searches might include: number of volcanic earthquakes per day; number of earthquakes in a certain magnitude range; and particular patterns of gas emission or land deformation. Parameters can be searched in any combination. WOVOdat will also include tools for mapping, and plotting time-series data, plus others for 3D visualization, pattern recognition, and decision-support. More tools will be added later.

This means volcanologists will be able to input present conditions of their volcano, and instantly obtain data about similar occurrences.

To understand eruption precursors, think of a mass of gas-rich, molten rock (magma) forcing its way to the surface through a narrow, partially blocked pipe. Pressure causes local earthquakes, which increase in frequency as the magma nears the surface. It also causes the volcano to inflate like a balloon, though precise instruments are usually needed to detect it. And gas begins to leak from the magma like the fizz leaks out of soda pop when the cap is loosened.

WOVOdat will be used for volcano-crisis decisions, allowing early recognition of dangerous volcanic patterns. This will lead to more precise predictions and more effective evacuations. Ultimately, this will save lives.

At the same time, WOVOdat will also be an invaluable research and educational resource. Just as epidemiological databases help to identify the causes of mysterious diseases, WOVOdat will help to reveal volcanic processes and mechanisms.

How the idea of WOVOdat evolved

Professor Newhall, “godfather” of WOVOdat, encountered two volcano cases which fuelled his passion for building WOVOdat. The first was Mount St. Helens in 1980.

A few months before the eruption, the mountain’s flank developed a pronounced bulge (Fig. 2). As part of their effort to interpret that, American volcanologists searched the scientific literature for similar occurrences. They found Mt. Bezymianny, Russia, which in 1956 exploded laterally, and Mt. Usu, Japan, which produced a dome-shape ground deformation and minor eruption in 1977. The scientists wanted to know which of the two quite different eruptive patterns Mount St. Helens would follow. In retrospect, Mount St. Helens case was similar to Mt. Bezymianny.

Figure 2. Pronounced bulge in the flank of Mount St. Helens volcano before its eruption in 1980. Photo courtesy U.S. Geological Survey.

The clear difference was that at Mt. Bezymianny, the steep upper part of the volcano bulged out, whereas for Mt. Usu, it was practically a flat surface that bulged upward. Through Mount St. Helens’ experience, volcanologists now know that a volcano bulging from its side is far more likely to collapse and explode than one deforming from a flat surface.

If WOVOdat had existed, volcanologists could have quickly looked for dramatic bulging on the upper flank of a volcano, putting in a Boolean search for inflation, or shortening the length of an EDM survey line by more than 1 metre per day and would have instantaneously gotten matching results. Would the results have told the scientists exactly what was going to happen? No. But it would have suggested the most likely possibilities, and gave more credence to the likelihood of a laterally directed blast for the scientists who were on the scene. In fact, that idea had been proposed but was not accepted until too late.

A second case was Long Valley in California. A series of earthquakes began there, also in 1980, and by 1982 resurveying had identified a fifty centimetre inflation of the floor of the caldera (giant crater) since the previous survey. This caused a flurry of concern. The earthquakes had not been purely tectonic, as previously thought, but the result of both tectonic and volcanic interaction. Professor Newhall undertook a literature review to find out where else this kind of thing had occurred and what happened. He naively thought it would take a few months; in fact it took five years!

The more he investigated, the more it seemed that the observed patterns at Long Valley were typical for large magma systems with calderas. They are often restless, generally in a harmless way. This changed the interpretation totally. Where before people were saying, ‘Oh my God, the sky is falling!’ now they could say, ‘This unrest is within the envelope of normal activity at calderas, and we should watch it, but no, we do not think it is time to hit the panic button.’

The results about restless calderas were published as a two- volume reference, and it is still a definitive work today. However, it is not searchable in the sense of a Boolean search, nor is it a mere systemic look for fingerprints to match with a new episode of unrest. That is why we need data organised into a modern database that can be searched online. As of December 2010, WOVOdat is live and accepting data.

WOVOdat is now live and accepting data

First, WOVOdat is being populated with every available source of historical data. This will include the Smithsonian's collection, plus legacy data supplied by the global community of volcano observatories including much data that are currently not publicly available. Published data from journals and books give WOVOdat additional strength, though obtaining all of it poses exceptional challenges.

Apart from legacy data, WOVOdat also grows as recent and current monitoring data are added – including both baseline data from quiet periods and data of fresh unrest. All data are time stamped and geo-referenced. An example of comparisons between volcanoes is given in Figure 3, using the parameter RSAM (Real-time Seismic Amplitude Measurement, an integration of all sources of ground vibration).

WOVOdat will be opened for public use and downloads as soon as it contains enough data for key comparisons to be made. We would be delighted to hear from students who want to help us build it.

www.wovodat.org

Figure 3. An example of RSAM comparison from 4 different volcanoes: Mt. St. Helens (May 1985 dome building), Mt. Pinatubo (eruption of June 7, 1991), Mt. Spurr (eruption of June 1992) and Mt. Redoubt (eruption of January 1990). More information: www.wovodat.org

Text adapted by Prof. Chris Newhall and Elaine Chong from a previous article by Wayne Deeker.