Mount St Helens eruption

Information pertaining to the occurrence of cresols in surface waters was limited. STORET (1989) and the CLAPS (1988) contained no records for o-cresol in ambient surface water. o-Cresol was detected in freshwater samples from Spirit Lake, Washington, on August 7, 1980 and from South Fork Castle Lake and Smith Creek, Washington, on September 11, 1980 at unreported concentrations (McKnight et al. 1982). The presence of cresols was attributed to the Mount St. Helens eruption on May 18, 1980 (McKnight et al. 1982). Whether or not the cresols originated from wood fires or the actual eruption was not clarified. 

Rutherford M.J. and Hill P.M. (1993) Magma ascent rates from amphibole breakdown experiments and the 1980-1986 Mount St. Helens eruptions. /. Geophys. Res. 98,19667-19685. 

Newell R . and Deepak A., Mount St. Helens eruptions of 1980, atmospheric effects and potential climatic impact. NASA SP-458, 1982. 

Baxter P. J., Ing R., and Falk H. (1983) Mount St. Helens eruptions the acute respiratory effects of volcanic ash in a North American community. Arch. Environ. Health 38, 138-143. 

The eruption of a volcano is accompanied by emissions of water vapour (>70% of the volcanic gases), CO2 and SO2 plus lower levels of CO, sulfur vapour and CI2. Carbon dioxide contributes to the greenhouse effect, and it has been estimated that volcanic eruptions produce 112 million tonnes of CO2 per year. Levels of CO2 in the plume of a volcano can be monitored by IR spectroscopy. Sulfur dioxide emissions are particularly damaging to the environment, since they result in the formation of acid rain. Sulfuric acid aerosols persist as suspensions in the atmosphere for long periods after an eruption. The Mount St Helens eruption occurred in May 1980. Towards the end of the eruption, the level of SO2 in the volcanic plume was 2800 tonnes per day, and an emission rate of p 1600 tonnes per day was measured in July 1980. Emissions of SO2 (diminishing with time after the major eruption) continued for over two years, being boosted periodically by further volcanic activity. 

Kanamori H, Given JW, Lay T (1984) Analysis of seismic body waves excited by the Mount St. Helens eruption of May 18, 1980. J Geophys Res 89(B3) 1856-1866 Kawakatsu H (1989) Centroid single force inversion of seismic waves generated by landslides. J Geophys Res 94(B9) 12363-12374... 

Seismic Signals from the 1980 Mount St. Helens Eruption and Landslide... 

Seismic Sources from Landsiides and Giaciers, Fig. 1 The Mount St. Helens eruption and landslide 18 May 1980 (a) the bulge at the north flank (b) development of the landslide during eruption (c) landslide... 

We have 1(T) = v(T) = 0, where T is the duration of the landslide. This condition imposes a constraint on the derivation of the force history F(t). Kanamori and Given (1982) found that the data of the Mount St. Helens eruption can be fitted by a sinusoidal F(t) with a period of 240 s. 

Ash is the noncombustible residue remaining after the burning of any substance. Although quite variable in physical form and chemical composition, ash is typically composed of silicates, oxides, carbon, sulfur, and metals. Workers may be exposed to ash from coal and oil-fired power plants, ash from ineinerators, ash from wood and other plant materials, and volcanic ash. A significant portion of most airborne ash is in the respirable size range. Fisher et al. (58) and Hatch et al. (59) described coal and oil fly ash, Fruchter et al. (60) described volcanic ash from the 1980 Mount St. Helens eruption in the United States, and Alarie et al. (61) described ash from munieipal incinerators. 

---