@Quix @Oceander@the_docOK, I have picked Bob's brain on the subjects you mentioned and taken notes.
Your question: "Where on the West Coast does Bob think will likely zip open first?"
He took seismic data of the entire west coast, earth and ocean, including up through Oregon and Washington state. First, there are "tensors" - which are directional forces under the earth and under the ocean. These tensors are measured using certain instruments and are being measured today to determine where areas of directional forces are building or lessening. A model of these tensors give an idea where the greatest forces are and how they are changing over time.
He gives as an example, north of the Santa Maria Basin is an area where the beds are folded, called the Chevron Folds. These are off shore. Some of these folds are tighter than others and the tighter the folds the more directional tensor force is there. If the force by itself (considering only the force) caused a break there would be an earthquake and the earthquake would also be under land from the directional force. However, if, under the folds there is a smooth surface, the folds wouldn't break and no earthquake would happen. This is to show how many factors have to be included to determine what is going to happen. This is why Bob can't predict and neither can anyone else predict, the exact combination of earth/ocean "physics" which would cause a break at a specified time.
Your question: "What does he think about the juncture at the South end of the San Andreas Fault and the one just to the South at the Salton Sea?"
He says the physics of the earth/ocean there is such that neither I nor you would understand it if he wrote it down. It is an area of concern.
Your question: "How about the Juan de Fuca area?"
He said the San Andreas Fault runs off shore and becomes the Juan de Fuca Ridge - it is part of the San Andreas Fault. Once again, the physics is complicated but the area is a concern.
The Tehachapi mountain range also intersects with the San Andreas Fault and the concern here is due to plates and subplates off shore. I suppose that means if the San Andereas Fault breaks, that mountain range is also in danger of moving.
Now, let's go north:
He says: Off the northern part of Oregon through Washington state, off shore and under ground, he measured huge lava fields that were 10,000 feet thick and down to 20,000 feet thick (he said to tell you there is no oil there

). These lava fields created Mount St. Helens and Mt. Hood.
In conclusion, God created the universe and it doesn't stand still, is in movement all the time. Man does his best to understand it and try to predict the future, but there are limits to his knowledge. The complexities of earth and ocean topography, the earth's plates and sub-plates and forces therein and under are beyond our ability to predict what they will do when. Bob and I both use the Grand Canyon to realize the enormous power of God to create such on the earth.
Tomorrow, I'll tell you a story of Bob and his geology buddies when they were graduate geology students at the Grand Canyon and ordered to leave.