Apologies in advance if this is off topic but there are a lot PWers affected by the recent event: I have always found it interesting that some of the most seismically active areas of the world are also the most populated. The Mediterranean, California, Japan, etc. Thinking about it is likely because these areas would have more and better harbors, more mineral resources and always have the most breathtaking views and scenic wonders. Indeed it is the natural beauty that attracts many people to the Pacific Northwest and Alaska as both a place to live and as a vacation destination, including sea kayaker. But beware, the beautiful irregular sea scapes and spectacular mountains got that way because of the powerful geologic forces that formed them. I am a Professional Engineer and most of my life is spent doing seismic analysis and geotechnical investigation and inspections in the Puget Sound area on buildings and other structures and I have my own perspective on this. I have a lot of local geologic reference materials about the Puget Sound area for my work, and I have also spent my school years and much of my life in Southern California as well. There is nothing different about earthquakes in the Puget Sound and Los Angeles areas, both areas are surrounded by mountains, both are along the Pacific "Ring of Fire", both are seismically active. If there is any difference it is just that some of them in PS are deep, but we also get many more destructive shallow earthquakes as well. Also much of the Puget Sound basin can be liquefaction prone, fine grain alluvial outwash saturated with high water tables. These kinds of soils exaggerate the accelerations and are far less predictable. The fact that this recent event did not kill anyone is pure luck. I calculated that if this last event was at 5 miles deep, which is much more common, instead of 30 miles it would have released 36 times (that is 3600 percent!) more destructive energy at the surface. Needless to say there would not have been much of Seattle, Tacoma, and Olympia left. All of the older historic unrienforced masonry buildings would have been totally destroyed, since I have inspected many like them I am actually very surprised they are still standing at all even with the deep event. The Puget Sound area routinely has about 40 earthquakes a month, most are small and not noticed or are in remote, unpopulated areas which is actually most of Western Washington (despite what many in the area think, we are not crowed here, we are compacted into only a few high population density areas, but the truth is the whole state of Washington has only about half of the population which live within the city limits of Los Angeles alone, never mind LA county or even the whole LA metro area). I think it is because of this low population over most of the area that many have the false perception there is a much lower earthquake hazard in this area than California, and many have lobbied for, and we now have, much less rigorous seismic codes. And the kind of incredibly stupid and incompetent lawmakers we have around here would probably do the wrong thing even if they understood we had a problem. We currently build to a seismic zone 3 (approx. magnitude 6.5 event), I think we should be building to seismic zone 4 requirements (approx. mag 7.5) as they do in California. Even so most (but not all) Building Officials, architects, engineers, and builders do not know what they are doing anyway so adequate enforcement is another problem. There are usually smaller remote buildings damaged or destroyed by earthquakes in this area about every three years! Since there is almost never injures or deaths, and isolated to the remote areas, people forget and do not perceive this as a real danger. Yet during the recent geologic history of the area there have been over 18 events over mag 5.0, including 4 over 6.5 with two being the very destructive shallow types. One of the largest of these was a near surface event of mag 7.4 that was centered only about 30 miles east of where I am in Arlington (about 60 miles North of Seattle). Needless to say I designed and built my own house to meet a much higher standard than the building codes require. Interesting, despite the property damage, even severe earthquakes in the United States have never caused a lot of deaths, unlike many third world countries. Even so it causes a lot of panic in people, but historically your chances of getting killed in a major seismic event is almost non-existent. What is over 100,000 times more likely to kill you are things you have control over, what you eat, smoke, if you wear your seat belt in your car, wear a helmet on your bike, or do really stupid things in your sea kayak. But if you live in a seismically active area you will almost certainly sooner or later suffer property damage, and at the very least be greatly inconvenienced. Peter *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:33:20 PDT