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Joined 2026-09-21 Message
Incoming links: United States Geological Survey
A formulation of directivity for earthquake sources using isochrone theory by Paul Spudich and others Created 2026-10-24 Updated 2026-11-05
United States Geological Survey Open-File Report 2004-1268. Paul Spudich and coauthors derive a finite-source directivity measure from the distribution of arrival times across a rupturing fault. The explanatory discussion links apparent pulse compression to the rate at which radiation from successive patches reaches a receiver. pubs.usgs.gov/of/2004/1268/of2004-1268tagged.pdf
Blind-thrust mapping report by United States Geological Survey Created 2026-10-24 Updated 2026-11-05
Primary technical report hosted by the United States Geological Survey. Numbered mapping features 4 and 5, “Active fold scarp” and “Syncline axis corresponding to the base of a fold forelimb”, explain how exposed deformation relates to a buried thrust. Hosting does not imply that every author is employed by the agency.
Developing the theory in This Dynamic Earth 2026-10-25
Official United States Geological Survey account of the oceanographic, magnetic and seismic evidence behind plate tectonics. The page is a chapter of This Dynamic Earth, not a newly discovered examination solution.
Focal mechanisms or beachballs by United States Geological Survey Created 2026-10-20 Updated 2026-11-05
The United States Geological Survey explains lower-hemisphere focal mechanisms, compression shading, and the ambiguity between the two candidate fault planes.