50. Photograph taken just after earthquake in 1886 showing a typical craterlet. Depth of craterlet is about 1 m; width is about 2 to 3 m. The white material around the craterlet is vented sand. The black wall of the craterlet is humate-enriched sand (the A-horizon) that was located at and near the ground surface at the time of the earthquake.
For more information, contact Stephen F. Obermeier