The 1964 Alaska earthquake was a 9.2 centered SSE of Anchorage. I was
at Galena AFS at the time, on the Yukon River in the northern interior
just south of the Arctic Circle. It's fairly flat up there and after we
realized there was an earthquake, we could watch to the south and it
appeared that there were ground waves moving rapidly toward us. It
ultimately broke off the wooden flag pole in front of the chow hall.
The WW2-era wooden hanger and control tower survived just fine, some
bookcases toppled and spilled coffee was about all that happened. The
reinforced concrete alert hangars ... not so well. Much of the damage in
Anchorage was the result of liquification of the ancient stream bed
beneath it.
The effects of any given magnitude earthquake are almost completely
determined by the conditions at any given place. We had a couple of
not-high dipoles and one of those humongous LP arrays for the MARS
station. ACS went down, our dipoles worked just fine. That LP monster
is basically a poorly optimized 3 element yagi on any given frequency
and didn't work all that well.
Were I in the EMCOMM business and planning for a major widespread
disaster situation, I'd focus on the physical aspects of the antennas
... transportability, survivability, ease of deployment, weight, and the
like. The rest will be what it will be, and it will likely be enough
... at least until better can be arranged.
73,
Fred ("Skip") K6DGW
Sparks NV USA
Washoe County DM09dn
On 4/30/2017 4:15 PM, Walter Underwood wrote:
Right, an NVIS antenna is effectively a Yagi pointed at the sky. So put a
reflector on the dirt.
The Loma Prieta was a 6.9. The Cascadia area could produce a 9.0. Richter is a
log10 scale, so that is 100X as strong.
wunder
K6WRU
Walter Underwood
CM87wj
http://observer.wunderwood.org/ (my blog)
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]
