Outside The Interzone

Tuesday, May 21, 2013

Geo 365: May 21, Day 141: Lava's Got a Squeeze-Up...

...Daddy doesn't sleep at night. I'm not entirely clear on how squeeze-ups form, but I can generally recognize them. My understanding is that once the lava becomes confined within the exterior shell or crust- essentially, a lava tube that hasn't drained- more lava erupted at the top of the flow increases the pressure lower in the tube. If there is a fracture or joint in the area experiencing the increased pressure, the lava squeezes up and out, like toothpaste from a tube.

Photo run through Paint.Net's autolevel routine. August 21, 2011. FlashEarth location.

And for those who didn't catch today's tongue-in-cheek musical reference:

Monday, May 20, 2013

Geo 365: May 20, Day 140: All of Us Are in the Gutter

(Click the pic for full-size. You know you want to.) Most cinder cones eruptions follow roughly the same story line: they start with a volatile-rich phase, tossing out bubbly, vesicular lava, with gasses acting as the propellant. A large heap of these cinders form around the vent. Since the slope is limited by the angle of repose- the steepest that a loose material of a given nature can be piled without collapsing- cinder cones tend to all look quite similar. The material they're made of is all vesicular basalt, so they vary in size, but not much in overall geometry.

Later in the eruptive cycle, though, as the supply of gasses starts to sputter out, the basalt is no longer thrown from the vent by their escape. This is where some variation in the morphology of cones can arise. The basalt is still being driven to escape by pressure from deeper down, so it starts to push up the throat of the newborn cone. However, the hydrostatic pressure of that column of basalt is often enough to overcome the confining pressure of the pile of loose cinders. The newly vented basalt is denser than the now cool cinders, which often have a greater amount of void space than actual rock- this is called scoriaceous basalt, or scoria. So rather than rising to the vent of the cone, the younger lava simply plows through its bottom and side, and erupts as flows. I refer to these as breach flows, though I'm not sure that's the correct term. I do recall that when an entire side of the cinder cone is blown out and carried away by the later flows, that's called a breached cone. It only took a few moments looking around in FlashEarth to find a nearby example- tree covered, so clearly older. (just above the cross hairs, and there's another, north-facing, breached cone over to the lower right)

In the case of Lava Butte though, not enough of the cinders were excavated by the later flows to damage its symmetry. So we're standing in the middle of the area where those gouts of lava emerged from the cone's flanks. The edges of the flow cooled more quickly, and the middle more slowly. So the edges of the flow are topographic highs, while the center remained hotter and able to flow away, resulting in a low area. This is referred to as a lava gutter. And with deference to Oscar Wilde, I get a little starry-eyed every time I take this short walk. I know of no other spot that more clearly imbues the viewer with such a visceral sense of what the past looked like.

Panorama stiched with HugIn, and run through Paint.Net's autolevel routine. August 21, 2011. FlashEarth location.

Sunday, May 19, 2013

Sunday Funnies: If Spock Was President Edition

I would so love to see Obama respond to these inane "scandals" in this manner. Julia Segal

The Far Left Side

Funny to Me

Tastefully Offensive

Doodle Time "The internal monologue that goes on whenever I cave to junk food."

Funny to Me

Senor Gif

See Mike Draw

Senor Gif

Tastefully Offensive

Sober in a Nightclub

Senor Gif

Funny to Me

Meme-meme

"'Aliens' in 60 Seconds"

rosalarian:

Angelina Jolie had a double mastectomy, in case you hadn’t heard. How dare she remove those ticking time bombs from her chest, amiright? Like, hasn’t she learned by now that her body is public domain and we all get to vote on what she does with it? Sheesh, how selfish can ya get.

Funny to Me

Blackadder

"Well-played, Humane Society." Imgur

Funny to Me

Blackadder

EatLiver

Criggo

Meme-meme

"When I find a sample from two years ago, and try to remember what it is" What Should We Call Grad School?

Tastefully Offensive

Very Demotivational

Geo 365: May 19, Day 139: We Have Big Balls

Viewing the two lava balls in the left of yesterday's photo from a different angle. I'll reiterate that I'm not sure if "lava balls" is a term used broadly among volcanologists; Lava Butte is the only place I've seen it. At the same time, I want to acknowledge that the mechanism described on the interpretive sign there seems logical and the best explanation *I* can think of. The rabbit brush is typically 2-3 feet in height, so these are pretty big- maybe 10-15 feet in diameter. The thought of these incandescently hot, rolling down an active lava flow, is quite intimidating.

Photo run through Paint.Net's autolevel routine. August 21, 2011. FlashEarth location.

Saturday, May 18, 2013

Geo 365: May 18, Day 138: Balls!

Sitting on the rim of the basalt flow here are three objects that the interpretive sign describes as lava balls. These are said to form in the same way as cartoon snowballs: a bit up high breaks loose and rolls down the slope of the active flow, accreting more lava as it goes, growing into a large, roughly spherically-shaped, ball. It makes good sense to me, but the reason I'm putting it into such equivocal terms is that I have never seen the name "lava balls" anywhere else, nor have I seen similar features in photos. I'm not suggesting anything wrong, nor any better explanation, just cautioning a bit of skepticism on this one.

Photo unmodified. August 21, 2011. FlashEarth location.

Friday, May 17, 2013

Geo 365: May 17, Day 137: 7000

Reading the Wikipedia article yesterday, I found that this lava flow and Lava Butte are about 7000 years old. That's quite a bit of time in human terms, but not really enough in rock terms to allow weathering to create soils that will support plants. We do see some sage and rabbit brush here, but for the most part, it's barren rock. Mount Bachelor to the left, Three Sisters to the right on the horizon, and I think that's Broken Top as the lower peak in the middle.

Photo unmodified. August 21, 2011. FlashEarth location.

Thursday, May 16, 2013

Geo 365: May 16, Day 136: Trail of the Molten Land

The interpretive trail on the breach flow at Lava Butte, looking north at that cinder cone. The summit road is apparent, spiraling up the peak. While the flow is pretty fresh, there are some colonizing pines visible.

Photo unmodified. August 21, 2011. FlashEarth location.

Wednesday, May 15, 2013

Geo 365: May 15, Day 135: Jurassic Parking Lot

The closest Jurassic rocks are likely 150 miles away or so, in the Josephine ophiolite along I-5. Nevertheless, we found this Jeep fun, on our visit to Lava Butte. As yesterday, Three Sisters to the right, Mount Bachelor mostly behind the pine to the left.

Photo unmodified. August 21, 2011. FlashEarth location.

Tuesday, May 14, 2013

Geo 365: May 14, Day 134: Cascade Skyline

Looking west from Lava Butte toward the Cascade crest. Three Sisters are to the right on the horizon, and Mount Bachelor to the left. The late-stage lava flow, which occurred after the cinder eruption, is visible at the foot of the peak. A version run through Paint.Net's autolevel routine can be viewed here.

Photo unmodified. August 21, 2011. FlashEarth location.

Monday, May 13, 2013

Geo 365: May 13, Day 133: Pilot Butte

Looking roughly north-northeast from the top of Lava Butte, Pilot Butte in Bend stands out just below the horizon to the right of center. Of similar sizes, these two cinder cones are both likely to be parasitic cones on the flanks of Newberry Volcano.

Photo run through Paint.Net's autolevel routine. August 21, 2011. FlashEarth location.

Sunday, May 12, 2013

Sunday Funnies: Depression Edition

Hyperbole and a Half- I have never read descriptions of depression that capture my own feelings in dealing with it as lucid and, at the same time, as funny, as the ones by Allie Brosh. I'm not having any serious issues with the disease right now- beyond housekeeping- but while this is long, if you have someone in your life whose depression is confusing you, you should absolutely read this and try to appreciate what she's saying. Advice, however well and lovingly meant it may be, is more often than not off-target.