Seismometers are an important part of the volcanologist’s arsenal. Small earthquakes often occur when magma pushes its way to the surface, and this handy tool will pick these up and record them. The earthquakes generally become more frequent and larger as the magma gets closer to the surface.
The tiltmeter is directly attached to the volcano. It measures small changes in the slope of the volcano, using a conducting fluid and a bubble, much like a carpenter’s level. When the bubble moves, the electrodes in the conducting fluid give off a voltage that the tiltmeter reads.
Volcanologists have the relatively new method of being able to use satellites to read the heat of volcanoes then send it to them digitally. Recording infrared radiation shows the heat and coolness as different colors will show whether a volcano is heating up for an eruption.
Another thing scientists look for when monitoring volcanoes is the amount and type of gasses emitted from it. When near to eruption, gasses become more pronounced and obvious. But, gasses sometimes are trapped by fast cooling lava and don’t come to the surface. Then the scientists cant tell if the gasses are more pronounced. Also, the gasses are hard to collect, seeing as they are extremely poisonous and need to be collected at the top of the active volcano.
Using these tools and methods, scientists are able to help people near possibly active volcanoes. When the seismograph shows signs of a major increase of seismic activity, when the tiltmeter detects changes in the surface of the volcano, when satellites find the volcano is heating up, and if gasses coming out of the volcano become more pronounced, then scientists know that the volcano is charging up for a blast that could kill thousands. Then they can evacuate the area and save those lives. That is the way scientists stand up to volcanoes and predict the next eruption.