Table 8 Ash thicknesses with impacts compared to previous ashfall events 1980-2010 (NI - Not investigated within studies; NA- Not applicable)
Eruption | Pacaya 2010 | Chaiten 2008 | Ruapehu 1995/96 | Rabaul 1994 | Mt Spurr 1992 | Hudson 1991 | Mt St Helens 1980 | |||
|---|---|---|---|---|---|---|---|---|---|---|
Localities impacted | Guatemala City | Futaleufu | Esquel | Gisborne | Rabaul | Anchorage | Perito Moreno | Los Antiguos | Yakima | |
Ash thicknesses (mm) | 20–30 | 80 | 15 | 3 | 600–1000 | 3–5 | 30–40 | 75 | 6–10 | |
Electricity | Flashover | ✓ | ✓ | ✓ | ✓ | NI | NI | ✓ | ||
Air intakes clogging | NI | NI | ||||||||
Switch abrasion | NI | NI | ||||||||
Controlled outage | ✓ | NI | NI | |||||||
Generator blockage | ✓ | NI | NI | |||||||
Water | Turbidity increase | ✓ | ✓ | ✓ | ✓ | NI | ✓ | ✓ | ✓ | ✓ |
Damage to pumps | ✓ | ✓ | NI | ✓ | ||||||
Filtration contamination | NI | ✓ | ||||||||
Clogging of filters | ✓ | NI | ✓ | ✓ | ||||||
Increased demand | ✓ | ✓ | NI | ✓ | ||||||
Waste water | Effects on sewer networks (clogging, wear on pumps) | ✓ | NI | ✓ | NI | NI | ✓ | |||
Damage to pre-screening equipment | ✓ | NI | NI | NI | ✓ | |||||
Power outages affecting pumping | ✓ | NI | NI | NI | ✓ | |||||
Ash accumulation in treatment tanks | ✓ | NI | NI | NI | ✓ | |||||
Roading | Road closures | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ||
Air filter blockage | ✓ | ✓ | ||||||||
Decreased traction | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | |||
Decreased visibility | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ||
Road markings covered | ✓ | ✓ | ✓ | ✓ | ||||||
Airport | Airport closed | ✓ | NA | NI | ✓ | ✓ | ✓ | NA | NA | ✓ |