It is impossible to precisely predict when a volcano will erupt or how large that eruption will be. However in attempting to make a prediction, scientists (geologists called vulcanologists) will look at the history of past eruptions to determine how the volcano has behaved in the past, this will tell the scientist roughly how often the volcano erupts and the type/size of these eruptions. If the volcano is considered to be 'active' or dangerous, the scientist will map the volcano determining it shape, and height precisely and install GPS sensors, tilt meters and seismographs on the volcano at strategic positions. These will then be monitored (usually from a remote location as the instruments will be capable of sending in their data by radio).
When the volcano starts to become active, earthquakes will be detected (starting deep and getting shallower and shallower as magma rises up in the volcano's Plumbing). As the magma reaches the upper magma chambers the volcano will inflate (get bigger / higher) and the tilt meters will tilt. When this happens the scientists will issue a warning that the volcano is likely to erupt.
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Before a volcano erupts, magma (molten rock) rises towards the surface, breaking rock en route. As more pushes up, the rocks around it vibrate. This results in earthquakes that can sometimes cause damage to buildings but are nothing like the big tectonic quakes seen on the west coast of the US or recently in Turkey.
Any sudden change in quake activity around an active volcano will, hopefully, give scientists enough time to sound warnings.
The magma also causes ground deformation. "As magma rises into a volcano, it has to make space for itself and that means that the ground has to swell," says McGuire. Every year, his team travels to Mount Etna to measure the relative positions of several reference points using sophisticated GPS recording receivers. Any changes in position - of the order of tens of centimetres - could mean the onset of an eruption.
David Rothery, a researcher in the volcano dynamics group at the Open University, uses another method of detecting potential eruptions. Many volcanos have craters at the summit but it is usually too dangerous to put instruments there. He peers at craters from space using satellites that measure infrared radiation, and looks for any sudden changes in heat activity. He says that, depending on the volcano, scientists will get anything from several months to a few days notice of an eruption.
In theory, then, eruptions shouldn't cause casualties. But this always depends on the evacuation plans for danger areas. Before Vesuvius erupts again, for example, 600,000 people will have to be evacuated, possibly at only a couple of weeks' notice. "It's a matter of political will, it doesn't come down to the science in the end," says McGuire
No. Although scientists can monitor signs that a volcano is getting ready to erupt they are nowhere near predicting the day a volcano will erupt. They might not even be able to predict the month or even the year that it will erupt.
how can you tell if a volcano going to erupt
A volcano will is generally a prominent feature that stays in one place. Monitoring seismic activity, gas emissions, and shifts in the surface on and near a volcano can be used to determine if an eruption is likely.
Scientists cannot predict with certainty when Mount Vesuvius will erupt again. However, the volcano is considered active, and monitoring systems are in place to detect any signs of increased volcanic activity that could indicate an impending eruption.
It is impossible to predict when a volcano will next erupt. As of July 2014 Kilauea is eupting now and has been doing so since 1983.
No. Although scientists can monitor signs that a volcano is getting ready to erupt they are nowhere near predicting the day a volcano will erupt. They might not even be able to predict the month or even the year that it will erupt.
how can you tell if a volcano going to erupt
They can't, volcanoes can erupt at any time
It is impossible to predict when a volcano's next eruptiopn will be.
A volcano will is generally a prominent feature that stays in one place. Monitoring seismic activity, gas emissions, and shifts in the surface on and near a volcano can be used to determine if an eruption is likely.
Scientists cannot predict with certainty when Mount Vesuvius will erupt again. However, the volcano is considered active, and monitoring systems are in place to detect any signs of increased volcanic activity that could indicate an impending eruption.
It is impossible to predict when a volcano will next erupt. As of July 2014 Kilauea is eupting now and has been doing so since 1983.
It is impossible to predict when or where the next major volcanic eruption will occur.
It is impossible to predict when a volcano's next eruptiopn will be.
Some are now in Iceland.
The number of times a volcano erupts varies greatly and depends on various factors such as its location, type, size, and geological history. Some volcanoes may erupt once and remain dormant for centuries, while others may erupt frequently over a short period of time. It is not possible to predict the exact number of times a volcano will erupt in its lifetime.
That happened in October 2009 in the past and it isn't going to erupt. It never even did.