"The earthquakes hit just days after last year’s near-catastrophe at Oroville Dam, when the spillway cracked amid heavy rains and 188,000 people fled in fear of flooding.
The timing of the two small tremors about 75 miles north of Sacramento was curious, and frightening. Were the quakes part of a seismic hot spot that caused the giant concrete spillway to tear? Was the weight of the water behind the dam triggering the quakes? Could all of Lake Oroville be prone to slipping?
A group of seismologists, summoned from the U.S. Geological Survey’s research facility in Menlo Park, was put on the case. Their findings were published in the Bulletin of the Seismological Society of America on Monday..."> GO TO: https://www.sfchronicle.com/news/article/What-caused-nearly-20-000-quakes-at-Oroville-Dam-13473254.php
THEORY: It occurred to me that the 1906 SF earthquake could have been at least partially caused by the presence of Crystal Springs Reservoir -- which was constructed 1887-88. It took about 18 years for seismic pressure and/or subterranean water fed by the reservoir to build up and spread right around the time of the expected 100 year quake -- causing the fault to slip roughly 20 feet along a 100 mile section of land from Loma Prieta to Marin County 18 April 1906. And the other side is; the presence of the reservoir has also so lubricated the fault that the 1989 quake was much smaller than 1906; and perhaps/hopefully subsequent earthquakes will be substantially less severe due to the constant lubrication of the tectonic plates in this region.
"Crystal Springs Reservoir is a pair of artificial lakes located in the northern Santa Cruz Mountains of San Mateo County, California situated in the rift valley created by the San Andreas Fault just to the west of the cities of San Mateo and Hillsborough, and I-280. The lakes are part of the San Mateo Creek watershed..."
"The southern lake, Upper Crystal Springs Reservoir, was formed when a tributary, Laguna Creek (or Lake Creek), which joined Laguna Grande at the south end, was submerged by construction of an earthen dam (this was the first Crystal Springs Dam) in 1877. The old earthen dam became a causeway between Upper and Lower Crystal Springs Reservoirs when the latter was formed by Herman Schussler's 150 foot tall concrete Crystal Springs Dam, which dammed up San Mateo Creek to form the lower (northern) reservoir in 1888..."
GO TO: https://en.wikipedia.org/wiki/Crystal_Springs_Reservoir + SEE ALSO: https://phys.org/news/2018-06-earthquakes-san-andreas-fault-large.html
Question: was the 18 April 1906 SF quake larger and more severe than all other annual 100-year San Andreas quakes along the same stretch of fault? If so my theory may be correct...
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SEISMIC/METEOROLOGICAL CONNECTION?
Note: A California hurricane is a tropical cyclone that affects the state of California. Usually, only the remnants of tropical cyclones affect California. Since 1900, only two tropical storms have hit California, one by direct landfall from offshore, another after making landfall in Mexico.
Since 1850, only seven tropical cyclones have brought gale-force winds to the Southwestern United States. They are: The 1858 San Diego hurricane that was reconstructed as just missing landfall in 1858, the 1939 Long Beach tropical storm that made landfall near San Pedro in 1939, the remnants of Tropical Storm Jennifer-Katherine in 1963, the remnants of Hurricane Emily in 1965, the remnants of Hurricane Joanne in 1972, the remnants of Hurricane Kathleen in 1976, and Hurricane Nora in 1997, after it was downgraded to a tropical storm.
August 18–19, 1906: A tropical cyclone moved northward from the Gulf of California, and brought rain to southern California...
SOURCE: https://en.wikipedia.org/wiki/1906_Atlantic_hurricane_season + SEE ALSO: http://lreresearch.blogspot.com/2014/02/seismic-meteorological-connection.html
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