Monday, July 6, 2009

FIRE!

It is OK to yell "Fire!" in a crowded blog, if it's not too crowded, isn't it? It looks as if fire season is underway in Oregon's forested lands. KGW (a Portland TV Station) is reporting a 300-acre fire near Black Butte, which is a marvelously beautiful cinder cone a bit west of Sisters.

In the Google Earth oblique view, I have highlighted three central Oregon Cascades features: The Butte (not a true butte, but the misuse of the word is epidemic in the PNW), the crest or watershed of the high Cascades, and Green Ridge. (Click for bigger, and note 2X vertical exaggeration). The central Oregon Cascades have been shown by Ed Taylor to sit in a graben; the subsidence of the graben is apparently synchronous with the development of the modern, or "high" Cascades. Green Ridge is the eastern side of the graben, and displacement was shown on the basis of mapping and water well logs by one of my most enjoyably memorable TA's, Rich Conrey. Rich was the TA who taught me how to make thin sections, so I had an opportunity to look at rocks I had collected, rather than just department specimans.
So Black Butte is considered to be a cinder cone that developed on the normal fault that created Green Ridge.

This general area, in the immediate rainshadow of the Cascades, gets enough precipitation to support a magnificent ponderosa pine forest, but when it gets dry it's really dry. Furthermore, when disturbances move through (as one did yesterday), rain often evaporates before it reaches the ground. Lightning associated with such storms, unfortunately, does not. This is believed to be a lightning-caused fire.

So firefighters are very dependent on breaks of cool, wet weather to bring these puppies under control. I'm sure many would be tickled pink for the conditions shown in these pictures from late December... about freezing and snowy:
From a few miles east of Sisters, looking west; Black Butte is about 10 miles away, and the Cascade crest is socked in.
Looking up and NW at the peak from its base. It's subtle in the original image, but with a little tweaking, you can more clearly see what I was trying to capture in this picture: a snowbow!
In honesty, I don't think "snowbows" can even occur. It was barely above freezing at this point, and I suspect snow at higher levels was melting as it fell toward the ground... making this more of a "mistbow" than either a snowbow or a rainbow.

I'd like to note, blooger has decided to rotate every picture I've tried to upload for the last few hours, won't allow me to unrotate them in picassa, and doesn't touch them if I put them in with a pre-emptive rotation- so they come up rotated the other direction instead. I've come up with a tedious workaround, but probably no more posts today. I'm pretty exasperated. But Happy Birthday to my Mom! This is also the one year anniversary of my web counter... this is an obscure little blog, with a few close followers, but it's grown enormously in the last twelve months. Thanks for all your comments and visits.

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