Saturday, September 12, 2020

THE LAND OREGONIANS LIVE ON

 I have a couple of maps. The first shows the lava flows from approximately seveteen million to about two million years ago. This map does not include lava and ash flows from the volcanoes in the Cascades. That is a whole different story.


These arethe basic flows that deposited up to two miles of basalt. Geologists are still working on where flows originated. Much of the basalt is what is found under the ocean, no extra minerals mixed in. Mixed lava is what is usually found in flows that originate on land. The basic shape of Oregon was already here. Then it was over run by molton rock from vents like the Siberian or Deccan traps. Some of those flows made it all the way to the Pacific, three hundred miles away.

This is a topogaphic map of Oregon. The green is the reletively low level, mostly flat terrain. There isn't very much.


The Columbia River forms part of the border between Oregon and Washington. The bend to the north is where Portland is located. Relatively little of Portland is actually on flat terrain Eugen/Springfield is down as the south end of the Willamette Valley. Hemmed in on three sides by the coast range and the foothills of the western Cascades. Most of the blue green to almost white running down the high Cascades are volcanoes ranging from extinct (we hope) to active in the last two hundred years. Hood, St Helens, and Ranier.

East of the Cascades you have the high plateau, the Ohocos, the Blues, the Wallowas, the Steens. They are not volcanic, they are what managed to stay above the lava flows and not pressed down under the weight of the lava flows.

The green. That's where most Oregonians live. Or close to it. Our mountains are young and steep, hard to access. No place in Oregon has recieved average rainfall for several years. And parts of southern Oregon are classed as in severe drought. And we only have records for say one hundred years. For all we know there were some years that were unusually wet. Hermiston averages about ten inches of rain a year. Less than that qualifies as a desert. There's a lot of scrub, small trees, bushes.

Anyway look at the topo map and try to imagine fighting a fire under those conditions. There were small towns on the McKenzie where there is a little flat land. At least one of those is gone. Nothing but ashes and rubble. This is a video taken by KGW in Portland Thursday. It runs about two hours with information from different locations.


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