Finely pulverized fragments of rock and lava which have been thrown out during a volcanic eruption. Volcanic ash forms a thick coating on the landscape adjacent to a volcano, and can travel great distances. Adey et al. (2011) TIBG 36, 3, 338 examine the way that the eruption of Icelandic volcano Eyjafjallajökull in 2010, revealed ‘the fragility of a tightly coupled, complex, and quite fragile network of airline movements, logistics chains, insurance products, and the complex supra-national organization of European airspace’. See also Ort et al. (2008) GSA Bull. 120, 3. Atwater et al. (2004) Holocene 14, 4 use volcanic ash as a dating method. A volcanic bomb is a block of lava ejected into the air from a volcano. As it is thrown out, it cools and spins; see Francis (1973) GSA Bull. 84, 8 on cannonball bombs.