Ash, Gas and Computers: the vulnerability of laptop computers to volcanic hazards

摘要

Volcanic eruptions are powerful, uncontrollable natural events which produce a number of hazards that can impact upon all aspects of society, including critical infrastructure. The most widespread and disruptive of these hazards is volcanic ashfall. Direct ashfall impacts, even minor, can cause multiple knock on effects throughout all critical infrastructure sectors leading to disruption of these services, on which society relies. However with appropriate volcanic risk management strategies, these impacts can be lessened.Electronic equipment, including laptop computers, are a common and vital component in all critical infrastructure sectors, field based volcanic research and wider society. Therefore, it is important to understand how laptops will function in volcanic environments. This thesis assesses the vulnerability of laptop computers to volcanic ash and gas hazards through field and laboratory based experimentation and the development of quantitative risk assessments metrics.Laboratory based ash vulnerability experiments were carried out in the Volcanic Ash Testing Facility, University of Canterbury, using a mass produced basalt ‘pseudo ash’, which is physically and chemically analogous to fresh volcanic ash. Each laptop was exposed to ash for 100 160 hours at fall rates of ~500 g/m² h. None of the ten laptops used sustained any permanent damage from volcanic ash, however, three shutdown temporarily due to overheating. This was because laptops only contain a few small ventilation holes which prevent large quantities of ash from entering the laptops. However, ash contamination reduced functionality of keyboards, CD drives and some cooling fans as these are open to the environment or located close to ventilation holes. Wet ash, known to cause short circuits of electrical equipment, was not able to enter the laptops because it is less mobile than dry ash. Functionality was retained with the use of simple mitigation techniques such as placing laptops inside heavy duty polyethylene bags.Volcanic gas vulnerability experiments were undertaken at White Island, New Zealand. Three laptops were exposed to high concentrations of volcanic gases for ~5 hours. None however, sustained any permanent damage, due to the limited quantity of gas that could enter the laptop, although metal components on the outside of the laptop sustained minor corrosion.