This article is from the source 'guardian' and was first published or seen on . It last changed over 40 days ago and won't be checked again for changes.
You can find the current article at its original source at http://www.theguardian.com/world/shortcuts/2014/sep/29/volcanic-danger-zone-scientists-predict-eruptions-japan-mount-ontake-eruptions
The article has changed 2 times. There is an RSS feed of changes available.
Previous version
1
Next version
| Version 0 | Version 1 |
|---|---|
| Life in the volcanic danger zone: how well can scientists predict eruptions? | Life in the volcanic danger zone: how well can scientists predict eruptions? |
| (about 21 hours later) | |
| Nothing else in nature can match the astonishing majesty and power of an erupting volcano. Get too close, however, and this extraordinary spectacle might be the last thing you ever see. Those climbers who lost their lives in Japan’s Mount Ontake eruption are just the latest additions to a casualty list that tops more than 80,000 in the past 100 years or so. | Nothing else in nature can match the astonishing majesty and power of an erupting volcano. Get too close, however, and this extraordinary spectacle might be the last thing you ever see. Those climbers who lost their lives in Japan’s Mount Ontake eruption are just the latest additions to a casualty list that tops more than 80,000 in the past 100 years or so. |
| It is impossible to say exactly how many active volcanoes there are on the planet. We do know, however, that around 1,500 have erupted at some point during the past 10,000 years, and all have the potential to erupt again. Indeed some, such as Sicily’s Mount Etna and Kilauea on Hawaii, are rumbling almost continuously. Alongside these are an equal number that have not erupted during the course of the last 10 millennia, but which may just be lying dormant. | It is impossible to say exactly how many active volcanoes there are on the planet. We do know, however, that around 1,500 have erupted at some point during the past 10,000 years, and all have the potential to erupt again. Indeed some, such as Sicily’s Mount Etna and Kilauea on Hawaii, are rumbling almost continuously. Alongside these are an equal number that have not erupted during the course of the last 10 millennia, but which may just be lying dormant. |
| These are the really scary ones, as, when it comes to volcanoes (all other things being equal), it is often the case that the longer the wait; the bigger the bang. | These are the really scary ones, as, when it comes to volcanoes (all other things being equal), it is often the case that the longer the wait; the bigger the bang. |
| With half a billion or so people now living in the danger zones surrounding the world’s volcanoes, honing the ability to predict future eruptions and, thereby, save lives, is something of a Holy Grail for volcanologists. This is proving to be somewhat easier than predicting earthquakes; a capability whose achievement is likely to remain some way off. | With half a billion or so people now living in the danger zones surrounding the world’s volcanoes, honing the ability to predict future eruptions and, thereby, save lives, is something of a Holy Grail for volcanologists. This is proving to be somewhat easier than predicting earthquakes; a capability whose achievement is likely to remain some way off. |
| There are two main reasons for this. First, for molten magma to open a path to the surface it has to break rock. This results in swarms of small earthquakes that are readily detected by seismometers. Second, the magma must also make space for itself; shouldering the surrounding rock sideways and upwards, causing the ground surface to swell. This can also be detected using any one of a variety of monitoring techniques, including GPS; albeit a more sophisticated version than the one we frequently abuse in our cars. | There are two main reasons for this. First, for molten magma to open a path to the surface it has to break rock. This results in swarms of small earthquakes that are readily detected by seismometers. Second, the magma must also make space for itself; shouldering the surrounding rock sideways and upwards, causing the ground surface to swell. This can also be detected using any one of a variety of monitoring techniques, including GPS; albeit a more sophisticated version than the one we frequently abuse in our cars. |
| For these reasons, it is surprising to read of reports announcing that the Mount Ontake eruption occurred without warning, and closer examination of the situation shows that this was not the case. In fact, since mid-September, increasing numbers of small quakes were detected by monitoring scientists, signalling that magma was on the move. | For these reasons, it is surprising to read of reports announcing that the Mount Ontake eruption occurred without warning, and closer examination of the situation shows that this was not the case. In fact, since mid-September, increasing numbers of small quakes were detected by monitoring scientists, signalling that magma was on the move. |
| At other volcanoes – including Pinatubo (Philippines) and Soufriere Hills (Montserrat) – analysis of the rates of increase of such “volcanic earthquakes” has allowed predictions of the timing of eruptions to be made to within a few days. Similar analysis of the Ontake data might have allowed a warning to be issued and saved lives as a result. | |
| • Bill McGuire is Professor Emeritus of Geophysical & Climate Hazards at UCL. His latest book is Waking the Giant: How a Changing Climate Triggers Earthquakes, Tsunamis and Volcanoes. | • Bill McGuire is Professor Emeritus of Geophysical & Climate Hazards at UCL. His latest book is Waking the Giant: How a Changing Climate Triggers Earthquakes, Tsunamis and Volcanoes. |
| • This article was amended on 30 September 2014 to correct a minor grammatical error in the final paragraph. |
Previous version
1
Next version