Hi All. The more I look the more I find that there is a very good chance that a mega quake off the coast of Northern California to British Colombia will occur without warning. If there are any warnings they won’t be recognized as such.

The current activity off the coast of Vancouver Island is to far to the west to be in a subduction zone so I don’t feel these could be considered a warning. However I could be wrong. The subduction zone is the trench between the Juan de Fuca Plate and the North American Plate.

Spreading at the Juan de Fuca ridge several hundred kilometers offshore produces the Juan de Fuca plate. It moves landward and beneath the continent at an average rate of 40 mm/yr. While this is happening Vancouver Island is moving towards the mainland at the rate of 7mm/yr. That is a little more then a ¼ inch per year.

The area in which a mega quake occurs is just a little to the east of where the Juan de Fuca Plate (JdFP) dives beneath the North American Plate (NAP.) It is this area that is locked tight. The western leading edge of the NAP is being compressed eastward like a giant spring. When it reaches a point that it will no longer compress it will most like give and when it does it will try to return to its normal location, as it would be when not being compressed. Using the Global Positioning System (GPS) of satellites, and a network of permanent GPS receivers, the relative motion of points on the earth's surface can be monitored at the level of a few millimeters per year. Points on the outer coast of the North American Margin, which overly the locked portion of the Cascadia Subduction Zone, move at rates of over 10 mm/yr in a northeasterly direction. The fact that inland sites move at half that rate, or less, indicates that the outer margin is slowly being compressed like a giant spring. At the time of the next great earthquake it is expected that the accumulated compression will be totally released and that the outer coast of southern Vancouver Island will move up to 5 meters to the south-west.

There may be one warning, but it is not known if this would occur or not, but the movement may slow then stop. It may even start to reverse, but as to how much time this would occur before the quake is unknown. It’s not even known if this would occur. At least I haven’t been able to find any mention of this.

The problem with trying to determine the time of the next mega quake is that there is no written history before the mega quake in 1700. There is geological evidence of more then just one mega quake occurring, but the times between them give no clue as to when the next one might occur. Take Care…Don in creepy town

• Juan de Fuca Plate