Geology Reference
In-Depth Information
FIGURE 5.8
Approximate percentage of time, annually, that the wind blows toward various sectors in western Washington. Frequencies
determined between 3,000m and 16,000m at Salem, OR, and Quillayute, WA (Crandell and Mullineaux, 1978).
FIGURE 5.9
Map of tephra thickness in mm from May 18, 1980, eruption. + = light dusting of ash, x = no ash observed, and
o = observation sites. Wind circle shows directions toward which wind is blowing, which were measured at selected altitudes (in
meters) at 10:20 PDT on May 18 at Spokane, WA. Data from U.S. National Meteorological Service (Sarna-Wojcicki, and others, 1981).
