What is the ash cloud made out of, anyway?
– Volcanic ash is mostly made up of tiny bits of rock, so small and light that they are easily carried through the air. The most recent eruption of Eyjafjallajökull occurred beneath glacial ice (which is, not surprisingly, fairly common in Iceland). The eruption melted much of the glacier, as you’d expect, but the cold caused the lava to cool very quickly and form minuscule particles of glass which got carried into the ash plume. 2. Planes can fly through regular clouds, so why can’t they fly through the ash? – All volcanic ash plumes can clog up airplanes’ sensors and coat the plane, thus adding to its weight and altering its delicate balance. This plume is particularly dangerous because of its glass particles, which can melt in the enormous heat of the plane’s engines and damage and/or jam the machinery. Jet airplanes flying through ash clouds have been known to have all four engines cut out, and propeller aircraft aren’t likely to fair much better. 3. All these particles are heavier
