In June of 1912, Alaska’s Mount Katmai erupted
with all the force of Mother Nature. As was the case with Kilauea
in Hawaii, the eruption offered an incredible opportunity for scientific
study. Despite this fact, four years passed before the first expedition
to the volcano. The party was led by R. F. Griggs of the National
Geographic Society.
Grigg’s mission sparked interest in the Geophysical
Laboratory to undertake a similar study of the mountain. Between the
years 1918 and 1923, C. N. Fenner, E. G. Zies, and E. T. Allen headed
the Laboratory’s own investigation to Mount Katmai and specifically
the volcano’s Valley of Ten Thousand Smokes.
At the Valley of Ten Thousand Smokes, Fenner, Zies,
and Allen collected rocks, looked into fumerole encrustations, measured
the temperatures of hot springs, helped in geologic mapping, and aspirated
exhalations for insoluble gases. The conclusions the three men formed
from this data were vast and detailed.
The scientists reasoned that the origin of the vast
sheet of siliceous rocks at Katmai was not lava but pyroclastic, having
been ejected as rhyolitic pumice through the broken valley floor.
Fumeroles measured 100 to 650 degrees Celsius. They were discovered
to decrease in heat over time and had a deep-seated origin.
Some of the best results Fenner, Zies, and Allen
found concerned the mineralogy of Katmai’s rocks. It was deduced
that the mineralogy of the Valley’s encrustations changed as
temperature decreased, and because many minerals of economic value
were formed, a relationship of ore deposits to volcanic exhalations
was subsequently established. In addition to these findings, the hybrid
nature of the rock samples led Fenner to believe that superheated
rhyolite magma had melted pieces of old andesitic lavas and integrated
them into the erupted pumice and ash.
Overall, the work that resulted from the Geophysical
Laboratory’s expedition was extensive and ground-breaking. The
detailed investigative work in mineralogy and geology established
the value of a multidisciplinary approach to solving geological problems.
For additional images of C. N. Fenner's expedition
to Katmai, please click here.
