Ash Fall Case Study

821 Words4 Pages
Ash-fall: Ash fall is a very serious hazard presented by volcanism in New Zealand. Ash consists of rock, crystal particles and volcanic glass. It is ejected from the volcano into the air with large particles between 0.1-10m in diameter usually landing about 1-2km from the vent while finer grained material only millimetres in diameter can be deposited much further away (GNS Science, 2010) [2]. It can affect those in close proximity to the eruption as well as those at greater distances. Ash can be hazardous to the environment, buildings, property and to people’s health. During the 1945 eruption of Mt Ruapehu, ash fall was a major hazard to both people and the environment. Ash is very irritant to people’s eyes and can cause breathing difficulties…show more content…
It caused many eye and throat irritations with hundreds of cases being reported to doctors and chemists in ash-affected communities (Johnston & Neall, 1995). Due to its composition, ash is very abrasive as it has sharp broken edges which can cause damage to buildings, cars and machinery, with damage to paintwork being a very common problem. Ash can also contaminate water supplies making them unsafe to drink along with clogging water pumps, making them unusable. Another major concern due to ash is its ability to affect the visibility especially on roads making it dangerous to drive through areas with heavy ash fall resulting in reduced speeds and road closures. Ash can also be damaging to crops, burying them and subjecting them to possible rot. Aircrafts are at risk of having propellers and other rotating machinery jammed. Therefore, it is common for flights to be cancelled and airports are often forced to close following a volcanic eruption. As stated by Johnston et al. (2000, as cited by Auckland City Council, 2009) the 1996 Ruapehu eruption caused the overnight closure of Auckland Airport for several days. These hazards highlight how ash produced by volcanism has environmental, social and even economic impacts on New Zealand and
Open Document