Fig. 6

Slope angles (degrees) versus tephra thickness measured normal to the slope at exposures of St Helens W at Ohanopecosh on Mt. Rainier, Novarupta tephra on Kodiak Island, and Tibito Tephra in the Western Finisterres. The Kodiak Island sites are spread out across about 50 km (see Fig. 3). The Western Finisterre data shows the mean thicknesses recorded at each of the 14 sites (in an area of a few hectares) listed in Table 3. The Ohanopecosh (Mt Rainier) measurements are in a small area with sites only 50 mm or so apart recorded against the local slope angle. At no site is the relationship between tephra thickness and slope angle strong