Unofficial re-review by Sasata

At the request of the original nominator, I've having a look at the article again after changes have been made.
Referencing is now much better than before. I've condensed a couple of repeating citations.

I still believe the article needs to follow standard Wikiformat, including a lead, and division of text into sections, with appropriate headers. The argument that the article is not long enough to warrant separate sections highlights one of the article's deficiencies—it doesn't give sufficient coverage to the information out there. A search of the ISI Web of Knowledge Academic Database pulls up 76 research articles (dating from 1991-2009), but only a tiny fraction of these are cited in the article. Here are some research studies that I would expect to be cited in this article:
Thorson RM. (1993). "Postglacial offset along the Seattle fault". Science 260(5109): 825–826.

Discusses data that confirms Holocene movement along the fault.
Karlin RE, Abella SEB. (1996). "A history of Pacific Northwest earthquakes recorded in Holocene sediments from Lake Washington". Journal of Geophysical Research-Solid Earth 101(B3): 6137–6150.
Gives a geohistorical perspective on the fault and discussion of the secondary effects that may have been caused by the fault.
Dewberry SR, Crosson RS. (1996). "The M(D) 5.0 earthquake of 29 January 1995 in the Puget lowland of western Washington: An event on the Seattle fault?" Bulletin of the Seismological Society of America 86(4): 1167–1172.
Analyses a 5.0 magnitude earthquake 25 km south of Seattle that is most certainly germaine to this article.
Thorson RM. (1996). "Earthquake recurrence and glacial loading in western Washington". Geological Society of America Bulletin 108(9): 1182–1191.
Effects of glaciation/deglaciation on earthquake recurrence and its effects on current paleoseismic approaches to determine recurrence frequency.
I could go on (and on), but I think you get the point. There's a lot of research out there that hasn't been touched on in this article, and for that reason, it doesn't meet criteria 3(a) ("it addresses the main aspects of the topic"). I think if you were to address some of this research, the size of the article would swell up and section divisions would suggest themselves naturally. And with section headers and beefed-up text, image placement is much easier.

I'm not a fan of the outgoing links. For example, when I click on the outbound link (... local native legends) I expect to be led to a page which discusses specifically the a'yahos legend, but instead end up on a general site about Indian legends and earthquakes. Perhaps the a'yahos legend is somewhere in one of those links, but I shouldn't be expected to hunt around for it myself. If there is a specific page which discusses a'yahos, then link to it directly, and use a web citation template. If not, then this outbound link should be in the external links section (or perhaps left out completely). Similar arguments apply to the outbound link for Lidar-based mapping that appears later. I shouldn't have to go to an external site to find a definition that helps me understand the wiki article.

I hope this helps you on your quest to get this article to GA status. Good luck!