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20 September 2019
This is an ex-eruption!
Recently, as chronicled in Scientific American, I was involved with amending the eruptive record at California’s Mount Shasta to remove an eruption that was supposedly seen by a French mapping expedition in 1786. USGS researchers had already been puzzling over it for years – evidence was slim, since the area was already prone to forest fires and there was nothing in the geologic record to suggest that it happened. William …
22 June 2011
Archival Gold: USGS National Geologic Map Database
Time for another of these, since I haven’t done one in a while! This Archival Gold post departs a bit from the photo theme, but it’s no less useful – in fact, it was one of the most useful websites I ever encountered as an undergrad. The U. S. Geological Survey’s National Geologic Map Database contains records of, and often links to, more than 85,000 maps related to a variety of subjects: geology, hazards, earth resources, geophysics, geochemistry, geochronology, paleontology, and marine geology.