Saturday, March 16, 2013

Saturd80's: Au Pairs

Two or three years ago, I went looking for this song on the innertoobz, without any luck. I was reminded of it again recently, and booyah! Paydirt! Yeah, it's a still photo, but I really like this song a lot, and I'm happy to hear it again, after a decade or more of missing it.
So while we're on the topic, here's a couple more from that group. "Come Again" is from "Urgh! A Music War." If you like post-punk/new wave music of the early 80's (and I do, you may have noticed), this movie is must-see. Go over to that wiki link and take a look at the artist/song listing to see what I'm talking about.
Finally "Sex Without Stress." Au Pairs had only two studio albums, but in them, they focused heavily focused on the politics of sexual relationships- a topic I find fascinating, even while I choose not to engage in those politics, for the most part.

Geo 365: March 16, Day 75: Looking Back

Looking back to the far end of the amphitheater at Fort Rock, you can see that the far, higher-based walls have not been as modified by erosion as much as the cliffs at the "mouth" of the feature. They're above the high stand of the pluvial lake. I've always kind of assumed that the lower mound visible in the center, which stands farther out from the tuff ring than you can see in this photo, represents the last dying gasp of this eruption, but I never mapped it carefully enough to get real evidence for or against that conjecture. I will say, though, the feature overall shows the same circular structure, and strike-and-dip patterns, as Fort Rock overall. Had we an hour or two to spend here, there's a rough dirt road (not open to private vehicles) that circles the internal perimeter of this park, and is a moderately easy walk- that is, there are some decent grades in places, which may have one or two hundred feet elevation change, max, but overall, it's a pretty flat stroll. And with the road, you're not fighting through or weaving around the ubiquitous sage and rabbit brush. Even as out of shape as I am, I wouldn't hesitate to set out on the loop.

For the more adventurous, just out of frame to the left, there's a long, not-too-steep slope that allows safe and relatively easy access to the top of the rampart on its west flank. I didn't get a photo of that spot, but it's a pretty obvious and heavily used path, visible here. It's safe enough that we took high school groups up there (after a quick talk about common sense and sudden death); the views out over the valley floor are very much worth it. But at this point, between the physical exertion, growing fear of heights, and increasing difficulties with balance, I have a feeling it's not a spot I'll get back to.

Photo unmodified. August 20, 2011. FlashEarth Location.

Friday, March 15, 2013

Geo 365: March 15, Day 74: More Pluvial Features at Fort Rock

Yesterday's view was shot looking approximately east; today's is turned to approximately southwest, looking toward the opposite end of the amphitheater. Again, there is an excellent example of a wave-cut notch at the foot of the cliff, and at least one distinct step a bit below that- for scale, I'm guessing that step is about the height of a typical adult, maybe 5-6 feet. There is also a hint of fossil shorelines on the low hill in the mid-distance; those are more distinct in the full-size view.

The fact that the "fort" at Fort Rock is open to approximately the south-southeast suggests that during pluvial times, at least, that is the direction from which prevailing winds came most often and most strongly. Thus wave erosion was most effective against that sector of the tuff ring. However, even in the areas where the edifice is largely removed, bare surfaces of the eroded rock provide plenty of opportunity to see structural clues as to what once existed overhead.

Photo unmodified. August 20, 2011. FlashEarth Location.

Thursday, March 14, 2013

Geo 365: March 14, Day 73: Wave-Cut Notch and Structure

Here we've climbed up from the parking lot to just below the high stand of pluvial Fort Rock Lake, which filled this basin during the Pleistocene. A prominent notch can be seen on the flank of Fort Rock, just below the line of the horizon, but numerous other horizontal lineations suggest that lake levels varied quite a bit above and below the level of that shelf.

I didn't think to document the structure of this tuff ring as well as I could have (kicks self), but as I said, this was a stop that was much more rushed than I'd have liked- we scrambled up to this spot, stuck our noses up against the outcrop, snapped a few photos, and buzzed off again. However, if you enlarge the photo to full-size (right-click, "open link in new tab"), you can easily see that the layers of palagonite tuff are dipping toward the interior. However, if you look carefully at yesterday's photo (taken near the parking lot, near the base), it's more subtle, but especially looking along the top of the tuff ring, you should be able to see the layers are dipping toward the exterior. This allows some insight into what this feature may have looked like before wave erosion started tearing it up, and how it formed. This diagram, from USGS Circular #838, may help clarify. A somewhat more detailed description, and the source of that diagram, can be found in this road log at mile 36.1.

One last thing to notice: the lake sediments here hold abundant groundwater. So while annual precipitation is more appropriate for semi-arid grassland, and approaching desert-like conditions, water is being mined for agriculture, in particular, center pivot irrigation, which in satellite views dominates the flat lake floor. Such a plot is visible just below the horizon on the right.

Photo unmodified. August 20, 2011. FlashEarth Location.

Wednesday, March 13, 2013

Geo 365: March 13, Day 72: Fort Rock

Looking up at Fort Rock from near its base, the precipitous cliffs of the tuff ring jump out. It's difficult, not just in this photo, but in real life, to get a sense of scale here- there's little but sagebrush for context. However, this spot is the one with the highest relief, and the Wikipedia page says the prominence is nearly 350 feet, so this is by no means a trivial edifice. The cavernous weathering over this surface is terrifically appealing to raptors. They nest and roost in those little hollows, which afford both protection from the elements, and, I'd imagine, an excellent vantage point to watch for prey in the surrounding agricultural flats.

As I've mentioned, Fort Rock is a smaller version of Table Rock, examined in detail over the past couple weeks, but without the final effusive basalt flows. It's also much better known, and has been designated a State Park. It's day-use only, but it does have bathrooms with running water, and shelters for picnicking. The facilities are minimal, and as the day was moving along quickly, we didn't spend as much time here as the feature warrants. However, we did manage to squeeze in some highlights, which I'll showcase in coming days.

Photo unmodified. August 20, 2011. FlashEarth Location.

Tuesday, March 12, 2013

Geo 365: March 12, Day 71: China Hat and Pine Mountain

Approaching Fort Rock State Park (which is out of view, just to the left), we stopped to admire the horizon to the north for a moment. The middle-left peak (left-most) is China Hat, which I think is a cinder cone, though I'm not really sure, just guessing from its shape. The next peak to the right is Pine Mountain, a rhyolite dome complex, and home to an astronomical observatory, I think run by the University of Oregon. It's another one of those spots I've never been to, but would like to visit eventually. I'm not sure what the low peak on the middle right is, but that's starting to get into the neighborhood of the Devil's Garden, a field of younger basalt flows, so it may be associated with that feature.

Photo unmodified. August 20, 2011. FlashEarth Location.

Monday, March 11, 2013

Geo 365: March 11, Day 70: Semi-Stabilized Dunes

Headed north from Table Rock into the Fort Rock-Christmas Lake Valley, unfarmed landscapes often have a sort of hummocky appearance. Here we see why: dunes. During dry periods, the vegetation dies back, possibly burning off, and dunes start to migrate. During moister periods, vegetation takes hold and stabilizes the moving sand. Here we see an example that's right on the cusp.

At the east, down wind, end of this basin, there's a fairly large tract of open dunes, which are interesting for a variety of reasons. In particular, they're composed largely of Mazama Ash.

Photo unmodified. August 20, 2011. FlashEarth Location.

Sunday, March 10, 2013

Sunday Funnies: Daylight Savings Edition

"When my time course runs through the daylight savings time change (and then I don't know what to do)." What Should We Call Grad School?
Bits and Pieces
Tastefully Offensive -LongCat's nemesis, ShortDog...
Are You Talking to Meme?
 Darius Whiteplume's Tumblr
Tastefully Offensive
Funny to Me
"What I told everyone I was going to do..."
"What I really did." (After submitting my mapping project.) Geology is Hard
Sober in a Nightclub
 "Star Trek Logic" Sober in a Nightclub
Doghouse Diaries
"Stephen Colbert finds the perfect candidate for today's GOP." What Would Jack Do?
Very Demotivational
Bits and Pieces
Historic LOLs
First, take a look at this optical illusion (original, full-size here works much better for me), then watch this video:
I find this not only funny, but very interesting: it seems to show that cat's visual perception system, with respect to this illusion at least, is similar to our own.
Tastefully Offensive
Julia Segal
"How trees are made." Senor Gif
"Dreaming about pipetting" What Should We Call Grad School?
Bless whoever it was wearing that costume. Wil Wheaton's Tumblr
 Matt Bors
Sofa Pizza

Geo 365: March 10, Day 69: Farewell to Table Rock

Looking out the window as we depart Table Rock, you can see the dirt road leading up to and into the complex. The area I've always parked in is in the junipers to the left, but the road continues into the interior and all the way up to the flat summit on the right. A target for future exploration...

But we had a number of other things planned for the day, and actually ended up doing a number of things we hadn't planned on as well. Time to go.

Photo unmodified. August 20, 2011. FlashEarth Location.