A review of a few definitions might be appropriate before starting the description of calderas and pit craters. These features are also described in Volcanic Landforms of Hawaii Volcanoes National Park. A vent is the "opening at the earth's surface through which volcanic materials are extruded" (Takahashi and Griggs, 1987). A caldera is "a large, basin-shaped volcanic depression, more or less circular ... the diameter of which is many times greater than that of the included vent or vents" (Bates and Jackson, 1980). A pit crater, like Halemaumau in the above photo, is "a crater formed by the sinking in of the surface; not primarily a vent for lava" (Macdonald and Abbott, 1977, p. 419). Photograph by Steve Mattox, 1995.

Previous Section

Back to Teacher's Guide

To VolcanoWorld

Next Section