9 November 2010

Common mistakes in reporting on volcanic eruptions

Posted by Jessica Ball

Volcanoes have been getting a lot of media attention this year, which is not surprising; natural disasters make for exciting stories. But your average reporter is likely not going to hold themselves to the same standards of research that science writers do, which ends up being detrimental to everyone, including their readers. Part of this may be because natural disaster stories are quickly written and not well fact-checked in an effort to get them out quickly. But with the wealth of good information available from scientific institutions these days, it’s pretty pitiful that the people who write about geologic events can’t take a little time to do research about their subject matter.

I’ll point out a few of the more egregious errors that I’ve seen recently (and in the past):

1. Pyroclastic flows (at Merapi especially) have been described as clouds of hot gas. This is obviously leaving out some important components, as anyone could see from observing the photos of areas affected by the flows. Pyroclastic flows are clouds composed of hot ash, gases, and rocks, which can travel at high speeds. They are not just gas or just rocks (although gas eruptions do occur, as do rockfalls and debris flows).

2. Magma is the word for molten volcanic material before it erupts; lava is what it is called after it erupts (reaches the Earth’s surface.) Yes, it is confusing that there are two words for the same material, but they help make a distinction between parts of the eruption process. Magma actually combines melted rock, crystals, and gas; when it erupts and becomes lava, more crystals form and some of the gas is released.

3. Volcanoes do not smoke. An eruption plume is, like a pyroclastic flow, usually composed of gases, ash, and rocks. Ash (pulverized rock) accounts for the darkness of the plume, but there is no burning involved. (This confusion may be due to the different meanings of ash; in geology, ash describes a size range of volcanic particles, while in other situations the word ash is used to describe the byproducts of burning organic material.)

4. One of the first questions that volcanologists get when a volcano is acting up is “When will it erupt?” – and it’s not a question that they can answer.Volcanologists forecast eruptions, but cannot predict them. Forecasting events means that volcanologists decide on the possibility that a particular type of volcanic phenomena will occur, but this operates in much the same way that a weather forecast does – with percentages and possibilities arrived at by observing all the available data and using the experience of the scientists involved. Because volcanic eruptions are natural processes, there is always an element of uncertainty involved in evaluating their potential behavior (which is why it’s inane to try and prosecute scientists for not predicting something, as with the Aquila earthquake). Naturally, we wish we could predict natural disasters, because that would mean that fewer people would be hurt or killed by them – and that’s one of the main goals of the scientists who study geological hazards.

5. Eruptions can last for a short or long time. It’s not at all unusual for an eruption to go on for days, weeks, months, or years. (Kilauea in Hawaii, which has been erupting since 1983, is an excellent example.) A volcano may be considered to be “erupting” even if the activity is relatively minor (a small lava flow rather than explosions, for example). So, the lengths of eruptions like the ongoing one at Merapi, or the one at Eyjafjallaj√∂kull earlier this year, should not be surprising.

6. Just because a natural disaster (such as an eruption) occurs around the same time as another one (like an earthquake or tsunami or another eruption) does not mean they are connected. Often such disasters occur in areas of the world, like Indonesia, that are prone to multiple types of dangerous geological phenomena – but proximity in time or geography does not mean that one event caused or was caused by the other.

This is by no means an exhaustive guide to writing about eruptions or other natural disasters, but I hope that it serves as a bit of a primer, and especially as a reminder to do a little research before you publish. It should be a goal of all news sources to report things as accurately as possible, and doing background research to make sure you understand your subject matter is a big part of that.

Addendum: In response to one of the comments below, I think it’s useful to mention a few websites with basic, correct information about natural disasters in general (and volcanic eruptions specifically). Fact-checking should not be difficult, given the vast internet resources available nowadays, but knowing whether a website is credible is definitely a hurdle for journalists with little science training. These websites are also featured in the blog sidebar.