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To: crz

Can you tell me what side slip and strike slip are? I know about subduction. I live in SW Or about 10 miles from the CA border and didn’t really feel anything but electricity blinked a few times.


39 posted on 12/05/2024 2:13:06 PM PST by little jeremiah (https://qalerts.app/)
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To: little jeremiah; Twotone; SunkenCiv; Liz

https://earthquake.usgs.gov/earthquakes/map/?extent=39.57394,-127.06787&extent=41.37887,-123.36823&range=month&magnitude=all&listOnlyShown=true&showUSFaults=true&baseLayer=ocean

This is a closer view of the BC-WA-OR-NorCal offshore Cascadia subduction Zone fault region. The Pacific floor tectonic plates are moving locally to the east, being forced down in a curve just off the coast. That is the long massive curve near the shoreline - where the plate bend down and begin melting. Further inland, that melted masses of water-filled pacific plate rock and sediment get liquid enough to bubble up through the contiental plate rock and form the rown of volcanoes abovbe 30-50 miles inland.

Further offshore though the still-solid rocky plate is moving (relatively) east as three different masses moving as three parallel surfaces.

The borders between the three small plates are the fault lines aimed west-east towards the shore. Quakes on the borders are side-slip earthquakes. Because one side is moving “sideways” compared to the other side.

Further south, on the San Andres fault for example, the fault line is also a side-slip earthquake. But onshore and far more visible since those earthquakes are underneath people. The danger of a sideslip earthquake offshore at this particular position is that it means the ultra-dangerous downward sudden massive quake is no longer being locked up by stresses and resistance in the side-slip edges of the tectonic quake.


43 posted on 12/05/2024 2:28:46 PM PST by Robert A Cook PE (Method, motive, and opportunity: No morals, shear madness and hatred by those who cheat.)
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To: little jeremiah

San Andreas and its accompanying faults are side slips..or strike slips.
Same thing. Somo of us like to use the more understandable term “side slip” instead of the more geological term strike slip.

The fault moves sideways horizontal in a quake.


51 posted on 12/05/2024 4:35:15 PM PST by crz
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To: little jeremiah

Also, side slip earthquakes dont tend to shake far away like a subduction quake.
If a large 8.0 or 9.0 subduction break were to happen, it would be felt 100s of miles away from the epicenter. The damage would be catastrophic.

We would most likely feel it very slightly here in NW AZ...depending on the geological mAkeup of the region between here and there.

Where you appear to be? Your gonna really experience something that will scare the heck out of you.


52 posted on 12/05/2024 4:46:23 PM PST by crz
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