However, it is better not to stay close, because lava emits poisonous gases. Notwithstanding that lava flows makes no loud sound, its emitting of poisonous gases can be hazardous for human health. Moreover, it is better to know and prevent potential damages caused by lava. These are two properties that are usually taken into account: viscosity, and gases (Rowland).
Viscosity represents a concept that explains lava’s fluidity. When the fluidity is high, lava cover large distances and is considered to be very dangerous. Such lavas can stop flowing only when they become cool and consequently solid and this process takes time. According to Nagata, “The variation in electric conductivity with temperature is expected to be closely related to that of the viscosity of the lava, as in the case of viscous glass, in which, as is known empirically, the reciprocal of the ionic conductivity caries linearly with the coefficient of viscosity” (Nagata, p2).
Temperature of lava is high. It is 1,250° Celsius (Rowland) in Hawaiian volcanoes, but generally, lava temperature can reach 750° Celsius. Therefore it is desirable to be as far as possible from lava flow. Nevertheless safe distance depends on activity of lava flow and direction of the wind but this distance preferably shouldn’t exceed 10 m (Riley). Lava is dangerous not only for humans, but also for everything around. Lava flow can surely damage some surrounding objects. Fortunately, concrete and iron can resist it. It can be explained as follows: Irons melting point is 2750°F in comparison to lava’s melting point 1300-2400°F. Furthermore lava can’t melt steel like other metals, dirt and rocks (Lava).
It’s worth remembering that lava moves not very fast and it is possible for people to outrun it. For example, hot Hawaiian lava flows about a few meters per minute while cool lavas flows only a few meters a day (Lava). But it is as well necessary to know that lava