Talk:San Andreas Fault

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it is scientifcally possible for the fault to 'break apart' isn't it. is there an estimate when this might happen?

Answer: probably in a million years or so...it moves like a CM a year

Also, the plates are not moving apart, they're moving sideways. -Will Beback 21:34, 29 May 2006 (UTC)

Is there an estimate of how many years it will take for Los Angeles to move so that it is parallel to San Francisco?

The arithmetic: 344 miles (554 km) divided by 1cm per year (given above) = 554 X 1000 X100 == 55.4 million years (roughly) - probably another 15-25my to separate into an island, a 2 or 3 hundred my to collide with Alaska. (This seems consistant with some numbers I saw on a Nova program, which I do not recall exactly). - Leonard G. 00:44, 29 September 2006 (UTC)

[edit] Added the new study from the journal Nature

Hey, everyone, I just added the new study by Yuri Fialko of Scripps Institution of Oceanography at the University of California, San Diego, which states that "the next big one" (magnitude 7.0 or greater) is "overdue" in southern California. Glad I live in Oklahoma. Take care. :) User:ProfessorPaul 01:14, 22 June 2006 (UTC)

[edit] Notice of availability of a new template

A new template is available, which can make for interesting reading in this article if properly used. The template, {{Days elapsed times factor}}, parses as follows:

{{ Days elapsed times factor | Year | Month | Day | Factor | Decimal places }}

This template calculates the amount of change since a given date. For instance, a template filled in like this…
{{Days elapsed times factor|1989|10|17|0.009582|0}}
…generates this numeric value, which automatically changes over time: 65

You might ask “Why is that nice?” Because one can use it to generate text like this:

“

This strain rate of 33–37 mm/year, which is about the speed at which a fingernail grows, may seem small. However, it quickly accumulates. Since the October 17, 1989 Loma Prieta earthquake roughly 19 years ago, the Pacific plate has moved approximately another 65 cm!

”

The virtue of this is you don’t have to go back and periodically tweak the value. Every 3.4 months, the template will increment the value an additional centimeter. To accomplish this, one need code only as follows:

This strain rate of 33–37&nbsp;mm/year, which is about the speed at which a fingernail grows, may seem small. However, it quickly accumulates. Since the October 17, 1989 [[Loma Prieta earthquake]] roughly {{age|1989|4|18}}&nbsp;years ago, the Pacific plate has moved approximately <u>another {{Days elapsed times factor|1989|10|17|0.009582|0}}&nbsp;cm</u>!

In the above text, 182 days was subtracted off the {{age}} date template so the number of years would round to the nearest value. In the {{Days elapsed times factor}} template, I used the actual date of the earthquake. The 33–37 mm slip rate was averaged and scaled to a centimeter-based value of 3.5 cm/year, and divided by 365.25 to obtain a daily slip factor of 0.009582 centimeters per day. It is always wise to have at least 32 times more precision in a conversion factor, which explains the jump from 35 counts to 9582 counts.

Here’s the “live” slip rate, displayed with excess precision: 65.263 cm

Sometime on March 22nd, the value (which as of this writing displays as 64.33355 cm and rounds down to 64 cm) will round up to 65 cm.

I will leave it to someone expert in the field of earthquakes to properly use this feature; I’m not sure as to what specific part of the San Andreas fault would be an appropriate place to reference a specific amount of strain.

Greg L (my talk) 00:39, 5 March 2008 (UTC)

[edit] Plate motion vectors

The North American Plate moves in a west to southwest motion as a whole. Nowhere does it move southEAST. That is only a relative motion along the fault line, relative to the Pacific Plate's motion. Tmangray (talk) 19:49, 4 April 2008 (UTC)

I was under the impression that both plates were moving in the same direction, just that one was moving faster than the other. Is this right? —Preceding unsigned comment added by 86.148.78.10 (talk) 23:53, 10 April 2008 (UTC)

The vectors of motion out of the MidAtlantic Ridge are westward to southwestward. I don't believe anyone has yet shown that the North American Plate changes its direction of motion intraplate. There is the still-unproven, but perhaps plausible idea that, assuming an asthenosphere-lithospheric traction force exists, the same mantle current carrying the Pacific Plate along also lies under the western part of the North American Plate, exerting some modification of its overall vector near the margin, and this might somehow be involved with the extensive faulting throughout the west as the underlying tractive force interacts with the southwesterly vector of the overlying plate. But so far, that's only a proposed hypothesis, I believe. Tmangray (talk) 17:23, 16 April 2008 (UTC)