Saturday, May 4, 2013

Geo 365: May 5, Day 125: Newberry Caldera and Surroundings

I realized yesterday that this would be post number 3000 at Outside the Interzone, and I wanted to find something special for it. I didn't have to look far. Our next stop after Lava Butte, which I've been poking around for the past week in this series, and to which I'll return in a week or so, was the top of Paulina Peak, on the southeast rim of Newberry Caldera. Actually, I think it was at the park's toll booth, but I took no pictures there. Below is an annotated version with the features I can identify labeled. You'll have to enlarge to read the labels... at least I will.
From left to right, we have the South, Middle and North Sisters, a set of related Cascade stratovolcanoes that get older to the north. This edifice as a whole has been mentioned as a possible multi-peak model for Mount Mazama prior to its catastrophic eruption, and I suppose that may be part of the reason the gentle swelling of the area in the past decade was monitored so carefully. I calculated the total volume of that inflation sometime in the past year, and if it did represent magma intrusion, it was pretty trivial. Mt Jefferson, another Cascade stratovolcano, is just barely visible though the haze. As I've mentioned before, "haze" is a relative term; that peak is probably in the neighborhood of 75 miles away. But this was late summer, so not only is the haze getting worse, but there's often smoke from fires as well.

The rim of the caldera is unlabeled, but we're seeing almost the entirety of it here. Paulina Lake fills the western portion of the caldera, but unlike the more famous Crater Lake, drains via a stream that exits to the west. North Paulina Peak is the high point on the northern rim. I have always assumed that the entire caldera was filled with a single lake, but a series of aligned eruptions at the Interlake Obsidian Flow, Central Cone, an unnamed (as far as I can tell), smaller cone between Central Cone and the road, and, most recently, Big Obsidian Flow, has divided Paulina Lake from East Lake. Pine Mountain, off in the distance, is another rhyolite dome, and is likely related to Newberry. The rhyolitic volcanism here is the most recent of a westward-younging series of rhyolite eruptions; Pine Mountain is the next youngest to the east. Finally, I think China Hat is a largish cinder cone based on its morphology and symmetry. It's the small lump above and outside the rim, not the high point on the rim itself. I've mentioned the latter two features earlier in the year.

Dana is coming into town probably about midday Monday, and we're heading over to the coast to see Otter Rock that first day, leaving us four days to tour the southern Oregon coast and northern California. I have some chores I need to get done tomorrow, so I'm trying to get as much of my Sunday internetting done today as I can. I've decided to try keeping up with the Geo 365 series on the fly, so I can share at least a few highlights of what we're doing each day. August 21, 2011 is going to take roughly a week's hiatus, after which I'll return to it. Even though I'm back on my newer machine (Yay!), Blogger is still a pain with respect to uploading photos- it just stalls out for five to ten minutes at a time, but once it actually starts to load, it goes quite quickly. I'll try to post a few quick picks each day here, but I'll also be posting these so-called teaser photos on Twitter. This will be in the later evening PDT, so way past the East Coast's bedtime. So if I miss a day here, see my timeline, and rest assured, I'll catch up when I can.

Photo unmodified. August 21, 2011. FlashEarth Location

Geo 365: May 4, Day 124: Ichnofossils

Ichnofossils, AKA trace fossils, in the sidewalk on the summit of Lava Butte. Of course, since the concrete is a man-made material, it's a pseudorock, and these are pseudofossils. Whatever. These are likely impressions left by a golden-mantled ground squirrel, which are very abundant and common in central Oregon, especially in relatively wild areas with a heavy human presence. They are very clever beggars, and can be quite bold about approaching people for handouts. They're tough to resist, but we don't help them by feeding them.

Photo unmodified. August 21, 2011. FlashEarth Location.

Friday, May 3, 2013

Geo 365: May 3, Day 123: Breadcrust #2

Another breadcrust bomb, very close to yesterday's. [Deleted rant about Google. Short version: time to go looking for other services that don't start out fine, then descend into chaos. When a post like this takes an hour and a half, something is wrong.]

Photo unmodified. August 21, 2011. FlashEarth Location.

Thursday, May 2, 2013

Geo 365: May 2, Day 122: Breadcrust #1

A breadcrust bomb, along the stairs from the parking area to the fire watchtower, at the summit of Lava Butte. "Bomb" indicates a blob of lava tossed in a still-fluid form from an active vent, and "breadcrust" texture forms when the exterior of the bomb cools and solidifies, but the interior is still somewhat fluid and degassing. As the sticky interior expands, it "crackles" the exterior shell in a manner very similar to the crusts of some artisanal breads. In the area where the exterior shell has broken off, above and to the left of the lens cap, you can see the foamy interior of the bomb. Foamy basalt is called scoria, just as foamy rhyolite is called pumice.

Photo unmodified. August 21, 2011. FlashEarth Location.

Wednesday, May 1, 2013

Geo 365: May 1, Day 121: Summit Crater

Standing on the north rim of Lava Butte, looking south to the west flank of Newberry Volcano, and into the summit crater of this cinder cone. The parking area here is on the small side, and since its designation as a National Monument in 1990, the area has become much more crowded. So the crew here has instituted a first-come first-served free pass system, where, at the entrance to Lava Butte, you can get a parking pass. I imagine a lot of the time, it's unnecessary, but when the lot gets gridlocked, it's a nightmare. The pass is good for half an hour, which would be plenty of time for the loop trail around the crater here. However, I was worried about time; like the previous day (See Geo 365, Feb. 18 through March 31), I had planned a lot for this day. The loop trail was something I didn't want to try to cram in. Just as at Hole-in-the-Ground, note that trees have become established on the north-facing south interior of the crater, but have a hard time elsewhere. I think these are lodgepole pines, rather than ponderosas.

Photo unmodified. August 21, 2011. FlashEarth Location.

Tuesday, April 30, 2013

Geo 365: April 30, Day 120: Lava Butte

Lava Butte, craning across the front seat, and looking out Dana's window. The rubble in the foreground is the aa aa lava flow that emerged from the south side of the cone during the latter stages of this eruption. As the magma works toward the surface, the more volatile-rich fraction tends to be toward the top, so the initial stage of the eruption blows off a lot more gas. Hence the cinders. Later, as less gas-rich magma becomes dominant, the lava erupted isn't blown out the vent, and will often push through the side of the cone as one or more flows. This is a very common pattern of behavior for cinder cones. Lava Butte is simply a very accessible and well-exposed example.

Photo unmodified. August 21, 2011. FlashEarth Location.

Monday, April 29, 2013

Geo 365: April 29, Day 119: Newberry Volcano

This needs to be seen full size (right click, open in new tab) to be appreciated. It's a panorama of Newberry Volcano, seen from the summit of Lava Butte. In terms of its footprint, Newberry is an enormous mountain, though its height above the surrounding terrain is relatively modest. It's an excellent example of a shield volcano, characterized by fluid, runny lavas like basalt. Dozens of single-shot parasitic cinder cones litter its flanks, including the one I'm standing on, here.

Photo unmodified. Stitched with Hugin. August 21, 2011. FlashEarth Location.

Sunday, April 28, 2013

Sunday Funnies: Business is Booming Edition

Texas Governor Rick Perry and Lt. Gov. David Dewhurst reportedly reacted "with extreme disgust and disappointment" to the following comic, by Sacramento Bee editorial cartoonist Jack Ohman. Poor Ricky. What a shame your fee-fees is hurt. That's certainly a bigger deal than a lack of zoning, regulation and safety enforcement that might have, you know, prevented such a catastrophe. Let me help you to the fainting couch, you fucking jackass.

Once again, disasters are all about right-wing fucks whose delicate sensibilities have been offended.
Married to the Sea
"When I think about my decision to go to grad school" What Should We Call Grad School?
Tastefully Offensive
"The recliners have become self-aware, and they are tired of your shit." Sofa Pizza
Senor Gif
"Sea is for 'cookie'" Sofa Pizza
What Would Jack Do?
Sober in a Nightclub
Sober in a Nightclub
Bits and Pieces
Tastefully Offensive
Derpy Cats
Derpy Cats... Sigh. Looks like someone let the air out of my cat again.
What Would Jack Do?
Tastefully Offensive
Wil Wheaton's Tumblr
Julia Segal
Funny to Me
"When I come back to society after a summer in the field" Geology is Hard
Bits and Pieces
Funny to Me Cool cats never look back at explosions.
Funny to Me
Matt Bors
Berkeley Mews
Funny to Me
Tastefully Offensive
Questionable Content
"When a student asks for an extension on an extension" My Life as a College Professor\
Jen Sorenson
 Gonna make you click over to see this whole story, but I promise, it's worth it.
In preschool when I was 5, the boys bathroom had to get a ceiling repair so everyone had to use the girls bathroom and when I was in there some kid named Jimmy walked in.
 "When I haven't read the news in a few days, all the headlines make me feel like..." How a PCV [Peace Corps Volunteer] Puts It Gently
When a local gives me some food and I have no idea what it is, I just look at it like... How a PCV Puts It Gently