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Landers Rupture — Ruth on impact to San Andreas

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Detailed Description

USGS seismologist Ruth Harris talks about how the 1992 Landers earthquake caused concern for the San Andreas fault.




Public Domain.


There was the Landers quake and then the Big Bear earthquake that occurred just three hours later, so we were very quickly doing calculations to try to understand the relationships between them and there was big concern because those earthquakes occurred very close to the San Andreas Fault. That was big concern that the San Andreas would rupture so that was probably the calculation we were doing the fastest – was to try to see how Landers and Big Bear changed the stress. My mentor Bob Simpson at the USGS in Menlo Park, he and I quickly were doing some calculations about that as was Ross Stein and his colleague Jeff King. And then there was also a team at Lamont that was also doing the same calculations using the same kind of computer codes so we're quickly trying to understand the relationship with the San Andreas and there was great worry that the San Andreas might rupture. So according to our calculations the San Andreas should have produced at least a moderate size earthquake, but it wasn't until long after that geodesy data did reveal that it may have slipped slowly, but that took a bunch of months to figure out. But, it did not produce the larger quake.

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