Mt St Helens 1980


Much of the region surrounding Mt. St Helens was used as forestry land. These trees were blasted over, snapping trunks and leaving timber on the ground. During the lateral blast, it was reported that several pieces of forestry machinery were thrown considerable distances. Since the eruption, 25% of the timber has been salvaged from the surrounding region, with hundreds of loggers in a large-scale salvage operation (USGS. 1997).


Crops downwind from the eruption were impacted from ashfallout. Crops exposed to thick ash accumulation were destroyed. However, the 1980 eruption of Mt. St Helens is an example of where positive outcomes have arisen due to ashfallout. Areas exposed to thin covering ash benefited as it aids in water retention. Apples and wheat yields were higher than normal due to above average precipitation rate. Surface crusting from ash assisted with moisture retention. Ash also provides beneficial chemical nutrients into the soil (USGS, 1997).

Ash was abrasive and lethal to insects. This in turn meant lower pollination of some crops occurring, most of which occurred with assistance from the honey and pollinator bees. The ash gets stuck in the dense hair on theie bodies resulting in inability to fly (Cook et al., 1981).

It was estimated that the total cost to primary issues (timber and agricultural loses) was $1.1 billion. Unemployment increase tenfold in the weeks following the eruption across the region, most of which was in the forestry and primary industries sector.