Shake the Coastline

January 7, 2016

ttgraphSunshine on occasion this Thursday morning on California’s north coast, a bright-spot in between sprinkles and outright-rain.
Another storm is due in on Friday, and according to the NWS, maybe the next sustained sunshine on Sunday.

Beyond the new-normal, extreme-weather weirdness, another freaky-deeky concern is ‘normal‘ earth movements — last night we experienced a 4.3 earthquake less than 50 miles south of me (USGS).
I felt not a shiver-feel of a movement falling asleep — since then, a 3.6 shaker just after midnight, about the same place, followed shortly by a dinky 2.0, and nearly three hours later, a 2.7 a few miles west of there.

Earthquakes might be more-scarier than tornadoes…

(Illustration: USGS’ ‘Earthquake Travel Times,’ found here).

And to increase the fear factor are earthquake “swarms” — supposedly the last 10 days, five shakers 3.0 or greater shook near-identical locations about the Rio Dell/Ferndale/Fortuna/Cape Mendinco area south of Eureka. Along with the biggie last night, the New Year started-off shaking, too, with a 4.4 magnitude the evening of Jan. 1.
Of course, we’re nowhere like San Ramon down in the Bay Area — more than 500 quakes in the last month. And the “swarm” continued yesterday afternoon, with the Silicon Valley’s MercuryNews adding perspective: ‘Despite the recent cluster of constant shakers, the 3.1-magnitude quake was the first temblor stronger than 2.0-magnitute reported in the city in the last 24 hours.’
A whole day without a twofer…

Up here where I’m located is a scary geological place. Maybe worse than the infamous San Andreas fault is the Cascadia Subduction Zone (CSZ), which starts about the same vicinity as all our recent seismic activity, and runs along the northwest Pacific coast to Canada — below where I live all these plates/geological matters come together, grind and shake.

This local blurb about our earthworks via KrisWeb:

The best known geologic feature in northern California is the San Andreas fault (Oakshott, 1972), which extends north along the coast from San Francisco and ends at the “Triple Junction” offshore of Cape Mendocino.
The Triple Junction is where the American Plate, Pacific Plate and the Gorda Plate meet.
Earthquake hazards are greater to the north of the San Andreas fault because this region is part of the Cascadia subduction zone, where plate collisions increase the potential for huge earthquakes.

And what’s that ‘Triple Junction‘ thingy? According to the USGS, a sort of crustal traffic jam and ‘…one of the most seismically active regions of the San Andreas transform system.’

And even more personal, directly beneath me lies my own Mad River fault zone: ‘The principal faults of the zone are designated (from southwest to northwest) as the Fickle Hill, Mad River, McKinleyville, Blue Lake, and Trinidad faults (Carver, 1987 #4918).’

Just let loose the shakes…

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