Thursday, August 14, 2008

98 102 97 88

According to the Oregonian, those are the forecast temperatures for today through Sunday. Eee-yuck! And to make matters worse, that's the Portland forecast. We often get it worse here in the valley... I should explain.
Northwestern Oregon and the Willamette Valley
The Willamette Valley, in plate-tectonics-speak is a forearc basin, not a true valley. Out to the west of my favorite coffee shop about 100 miles, the Juan de Fuca plate slides under the western edge of the North American Plate. Come in from there about 50 miles and you hit the coast. Between the coast and here is the forearc ridge, aka the Coast Range. The Coast Range extends up to southern Vancouver Island (Canada), and south to about Coos Bay (the little upside-down "V" in the southwest corner on the map above. South of Coos Bay there's still a topographic ridge associated with subduction, but the rocks are very different (the Klamath province is a freakin' mess that I don't want to touch right now), so it's considered a different range. Likewise with what is also known as the Coast Range in California- different rocks, different history, therefore different mountain range. The forearc ridge is a line of uplift associated with compression at a subduction zone. The subduction takes place on a north-south line, and the Coast Range parallels the subduction zone.

Likewise with the forearc basin... but let's jump ahead to the Cascades. When a subducting plate reaches a certain depth (I seem to remember 150 km- 90 mi- but I'm not certain), hydrated minerals start "sweating out" their water. This water moves into the overlying hot rocks, reducing their melting temperature slightly, and causes them to melt. The magma moves upward, and the portion that reaches the surface erupts as volcanoes. This set of volcanoes parallel to the subduction is called a volcanic arc: most are curved (arc-shaped), but the Cascades are short as arcs go, and its axis doesn't curve much. Hence, forearc ridge and basin: the ridge and basin on the forward side of the arc.

Marys Peak
While the Coast Range has passes at about 1000-1200 feet elevation, the Cascade passes are about 5000 to 5500 feet. Typical peaks in the Coast Range are 2000-3000 feet, with the high point 4101 feet at Marys Peak just west of My Favorite Coffee Shop... well, 14 miles as the crow flies. The Cascades peg out at the 10,000 foot range, with Mt. Hood topping out Oregon at 11,249 (Mt. Rainier in Washington is the overall Cascade champ at 14,410).

Mt. Hood

And in between these two mountain ranges lies the Willamette Valley. While the Coast Range has risen by compression, faulting and folding, and the Cascades by a build-up of lava, the Willamette Valley (aside from fluvial sedimentation), has not been raised up very much. It is referred to as a structural depression- its existence is not due to erosion by the Willamette River. And technically, a valley is created by erosion. While most basins in the west are referred to as valleys (sometimes as holes, like Jackson Hole), many are structural in nature, not erosional.
Now if you glance back at the relief map up top, you can see that the Columbia River cuts westward through the Cascades, swings north from Portland, then back to the west through the Coast Range. Throughout most of the length shown on this map, the Columbia is close to sea level. It's a great passage for air to move through in east-west directions. Here in Corvallis, we have high areas west and east. It's more difficult to get air movement across those mountains. Meaning that the air tends to heat up more (there's less mixing with air from the coast) and it doesn't blow out as well at night- so we have warmer nights. So we will probably get higher temperatures than those forecast for Portland.
And that's what all that geology has to do with 98 102 97 88. Don't think for a second that geology pertains only to rocks.

Chaiten Again

Just after I started this blog, I posted on Chaiten Volcano. This picture was taken shortly after that post. I just found it (this post) on the Eruptions blog- an absolutely terrific spot for excellent volcano pictures and information on current eruptions. I don't know that the blogger reports every eruption or event, but he's certainly hit a number that I haven't seen reported elsewhere. And he reported on the Kasatochi (Alaska, Aleutian Island) eruption and its effects on air traffic when those effects were still in the future- days before the papers picked it up.

There's a full size version of the above picture (without labels), and a wider overview here. In the overview, you can see the ash cloud and the base of the volcano in the northeast quadrant. Note that the label "harbor" in the above picture sits entirely upon a delta of volcanoclastic debris- in fact, if the label was double its size, it would still fit on the delta. If you look at the full-sized picture, look at the (I'm geussing) lahar deposit out onto the runway in the southeast corner. Given that this was taken at the end of May, and Chaiten is still chugging away, this town is going to take a long time to recover.

Wednesday, August 13, 2008

Would be Funny, if it weren't so tragic

This picture got quite a bit of circulation a few days ago, though no one I've mentioned or showed it to seems to have seen it before. I try to keep four-letter words to minimum here, but sometimes it seems justifiable. From this post at PunditKitchen. (Second link to homepage- well worth your time if you like a humerous treatment of current events)

Western Oregon Rain

The reputation of Western Oregon/Western Washington as all rain all the time is not completely unearned, but like most stereotypes, is basically wrong. Our rainy season generally starts in earnest in November, and tapers off through May and June. September sometimes sees real rain, sometimes very little. October normally sees a very nice Indian summer, but at least a few rain events. However, this is a little misleading. "Rain" here is more often than not just drizzle for hours; in my nearly 30 years here, I've only seen a couple of downpours approaching the intensity of storms in Southeastern Ohio that were part of typical summer afternoons. The climatic stats reflect this: the average annual rainfall in Athens, Ohio is 45 inches, while that of Corvallis is 43 inches. So despite the reputation, we actually get less rain here than many climates that are considered drier. The upside of our damp winter is that the temperatures are very mild most of the time- night lows in the mid to upper 30's, daytime highs in the mid 40's. I used to enjoy cold winter weather, but I don't miss it. The downside is that it's almost always dark and gloomy; I think most people aren't so much irritated by the rain as they are by the weeks of deprivation of sunshine. We actually have a term, "sunbreak," for those couple of minutes when the sun peeks through the clouds during the winter.

But the point here, and a major misperception among many people I've talked to, is that it's drizzly year-round. Not True. July and August, and generally most of September, are drier than anything I could have imagined before I moved out here. We have had two rains this summer. According to, neither of these produced a measurable accumulation, for a grand total of 0.00 inches of rain since July 1. So much for "all rain all the time."

The news item that brought this to mind is an article by KGW on roadside fires along about 50 miles of the I-5 Corridor near Eugene (about 40 miles south of us). It is not clear what caused the grass fires, but officials are speculating "that vehicles with mechanical problems or with metal scraping the roadway may have created sparks that ignited in the dry grass and brush lining the interstate." This simply wouldn't have happened in the Midwest; it's too moist. Apparently a truckload of hay driving through the area picked up an unwelcome hitchhiker.

There's more pictures here. Apparently the traffic delays are pretty extreme. I'm happy just to sit here, drink coffee, and read about it. Happy I don't drive.

Followup: According to an article in our local rag, the Garbage and Trash, er, ahh, the Gazette-Times, the burning hay truck pitured above actually stopped near Jefferson, which is about 15 miles north of Corvallis on I-5. This suggests the fires were burning from Eugene to the north, not centered on Eugene as I had inferred from the first article.

Quote of the Day, Maybe of the Year:

"I sincerely doubt I'm the only person wishing that Bush Brand Conservatism were given a proper burial with an actual grave, just so I could piss on it."

From Melissa McEwan
Full article on the funereal mood leading up to the GOP Convention here.

Sunday, August 10, 2008

Flyby of Enceladus Tomorrow

The Cassini proble, which has been orbiting Saturn for just over four years now, is scheduled to pass over Enceladus (en-sell'-a-dus) in 16 1/2 from the time of this writing. Not that the precise timing makes a whole lot of difference.

Enceladus presents an interesting problem. One of the bands in Saturn's rings appeared to be associated with this moon, but it wasn't clear how. In an earlier pass, Cassini managed to image jets of water ice spraying from some structures (referred to as tiger stripes) near the moon's south polar regions. This phenomenon can be thought of as water volcanism- here on earth, we tend to think in terms of silicate volcanism- most lavas are silicate-based, and cool to form silicate minerals. In rare cases- for exampe in the rift valley of eastern Africa- there are carbonate based lavas. But water volcanism is not what we generally think of when we imagine a volcano (though I think that technically a geyser could be considered a water volcano).

At any rate, this upward spraying "snow" apparently accumulates to form the aforementioned ring. Now we know of volcanism elsewhere in the solar system. Io, a moon of Jupiter, is the most volcanically active body known. Since Io's orbit is not perfectly round, there is a point in its orbit where it's coser to Jupiter and an opposite point when it's farther away. "Tidal forces" is simply a way of saying that when an object is closer to another massive body, there is a difference in pull between the closer face and the farther face- the first object is stretched out. When the first object is farther away in its orbit, it relaxes a little. In the case of Io, this stretching and relaxing (often referred to as gravitational kneading) creates enough internal friction to generate heat that in turn drives its intense volcanism.

In the case of Enceladus, it's far enough away from Saturn, and small enough, that such gravitational kneading shouldn't be able to generate enough heat to drive volcanism. So what's the heat source?

We don't know.

Damn, I love those words. Yay! A puzzle!

According to this article, the probe will pass only 50 km (30 mi) over Enceladus' south pole, and be able to imagery with resolutions with as small as 7 m (22 ft) per pixel. The previous pass in March was optimized to use the fields and particles instruments; this pass is optimized to capture imagery. That means we should get some really exciting pictures tomorow. I do recommend reading the above lined article if your interested in this sort of stuff; I wish more science journalism was of this quality- not too much jargon, but clearly the author assumes some background knowledge. She recognizes that 1) I'm not an idiot, and 2) it's important to know her stuff. Most science reporters, unfortunately, make the opposite assumptions on both points.

You can follow the action at the Cassini website, (The lead picture is from here) or check in at a later date to check out the cool pictures.


Last Saturday, I noted that there was a buzz about some discovery on Mars that had implications for the possibility of life on that planet. I've been meaning to get to this for a while, but on Monday or Tuesday, NASA held a hastily-arranged press conference and announced that Phoenix had discovered- wait for it- Chocolate-Covered Strawberries!

Ok, Ok, not really. The chocolate covered strawberries gag was put together to lampoon the over-reaction by bloggers and commenters like me that had taken this story and amplified it into something a little more noisy than a Saturn V liftoff: maybe more like a medium-yield strategic nuke. In my own defense, I have to say that while I was excited, I was careful not to speculate. I was going to say, "speculate beyond the available information," but looking back over that post, I pretty much laid out the parameters of what we knew then and what we might be capable of discovering with the instruments available. I didn't really speculate at all. Although I made it clear that any possible discovery of evidence of life was a very exciting idea that would be the most momentous thing science had ever accomplished.

Turns out what they think they've discovered is evidence of perchlorate, a combination of oxygen and chlorine. Perchlorate is a strong oxidizer that at first glance might seem to argue against the probability of living organisms. Just as bleach (sodium hyperchlorite- a similar oxygen-chlorine compound) kills bacteria by creating an oxidizing solution that chemically "burns" them and breaks down the complex organic molecules that create pigments and stains, so perchlorate in high concentration would be very damaging to living things. However it turns out that in lower concentration, there are bacteria that use perchlorate as a source of oxygen just as we use free oxygen in the air. Furthermore, in the Atacama Desert, the driest desert in the world, where an inch or two of rain might fall once in a decade, perchlorate can build up as a result of UV light interacting with salts and the atmosphere. (Rains wash it away, and allow it to react in solution with other materials). So perchlorate is neither totally adversarial to life, nor is it's presence evidence that life cannot or does not exist in the neighborhood.

So what happened? Looks like this was one of those "A little bit of knowledge can be dangerous" situations. Someone told a reporter that there was a discovery, but didn't provide enough information for even a knowledgeable reporter to draw reasonable conclusions- I'll ignore the fact that most science reporters don't know enough science to report anything but what they're told. The report that the White House had been briefed, for example, was overstated. The president's science advisor was briefed. But the president doesn't even know he has a science advisor, so it's unlikely he ever heard about this issue. As noted above, depending on how you approach the issue, the existence of perchlorate could be an important indicator of an environment's hostility or hospitality toward life... or not. What the reporter apparently heard- correctly or not- was that the purported discovery had a direct bearing on Mars' ability to support life. This might have been an error on the part of the reporter or the leaker, who knows, and who cares? It was an easy mistake. I don't harbor anger toward either, but it does highlight the idea that clarity of communication is of utmost importance.

Some have made a big fuss over the kerfluffle sometimes with wry humor, sometimes with righteous indignation- how dare amateurs get excited and run with unsubstantiated rumors. This is science: a grave and serious business best left to the professionals. I call bullshit. In my opinion, his was a case of no harm, no foul. Wry humor is appropriate.

And to add to the confusion, the wording is that there is "substantial evidence" of the presence of perchlorate. The two wet-lab runs picked up evidence of the substance, but the TEGA (Thermal Evolved Gas Analyzer) instrument did not. This might be because it was not run in such a way as to detect chlorine, or because some perchlorate compounds would not break down under the conditions that samples in the TEGA are subjected to. More tests of both types will be run over the next few weeks to clarify the results.

So in the end, you could characterize this as a false alarm. An interesting one. One that tells you quite a bit about how science moves forward, and quite a bit more about its strengths and weaknesses.

Musical Road

When my brother and I went down to Death Valley in late March, at one point he commented it would be fun to have a road engraver- basically a diamond saw that cuts shallow grooves in the pavement to increase tires' ability to grip the road. His idea was that if you cut the grooves with predetermined spacings, you could drive across a section of road at a set speed, and the variations of groove spacings would create different tones. Short spacings would create higher tones, wider spacings would create lower tones. So you could drive a section of freeway for example and listen to the opening bars of Beethoven's Fifth: Dah-dah-dah-dahhhh.

Well, as it turns out, this has actually been done on section of road in Japan. I don't recognize the tune; I'm not even sure it's meant to be a "tune." It may just be odd sound effects. But it is an interesting effect. This might be very useful in combatting highway hypnosis. On the other hand, if you had to drive across this everyday on your way to work, it might get pretty old.

The Funniest Joke in the World...

...and quite possibly the funniest Monty Python Sketch ever. Which is saying a great deal.

Another item from my "notes" pad. As I mentioned in a previous post, I've figured out how to share items that show up in my reader. The items I've put on my shared page are most often things I want to post on, or things that are of particular interest to me. I have over a hundred items shared, so I guarantee I will not get around to blogivating about most of them. I invite you to skim over them yourself. Then when I do get around to writing up a few of them, you can congratulate yourself that you've already read that piece, and don't need to waste time actually reading my blog.

Lightning in a Jar

When I find an interesting link, or site or whatever in my cruising around the ISH (Information Super Highway), I copy the URL and a brief description over onto a notepad document I call "notes." These items are things that I want to post, so I don't have to track back to find them again- I just have to copy the information from the document into the composer. That does make it easier and more efficient, but I'm still falling behind- I have pages of notes of stuff that's now hopelessly outdated. Today I'm just trying to get some of that stuff caught up.

Since I have just posted another piece on lightning, this seems like an approprite place to put this vid clip- lightning in a jar. Technically, it's plasma, the fourth state of matter. Plasma is like gas (fluid and compressable), but the atoms and molecules that make it up are ionized- that is, the atoms and molecules are charged and there are free electrons flying around. This has a number of consequences: 1) the gas conducts electricity; 2) the gas is strongly influenced by magnetic and electric fields; 3) when an electron rejoins a charged atom or molecule, it gives off a photon (light), so plasma glows.

The previous post's video of a lightning strike shows points 1 and 3 very well. This picture of the August 1 eclipse shows point 2 well- the streamers of plasma in the corona are shaped by the Sun's magnetic field. (Bigger version here, and click the pic for a huge version. Since the picture is a composite of 28 images, the medium-sized version is actually the most impressive to me) Since plasma is conductive, as long as there is a charge difference between two regions in the plasma, electrons will flow from the negatively charged area to the positively charged area, keeping the plasma ionized. If you could get a plasma started in a microwave oven, the charges imposed by the action of microwave radiation on an ionized material would sustain the plasma for as long as the microwaves were hitting the glowing gas. Probably not a good idea, but fun to watch someone else do it. Unless, of course, you're this guy's girlfriend or wife. What in the hail are y'all doing?"


This has been all over the place for the last few days, but given that I recently posted on an article about lightning, I feel justified picking up the tail end of the virus. One note I read on it said that this was shot at 6000 frames per second. This is a fascinating video that allows you to see different phases in the development of a lightning bolt. First, as the charge difference between the cloud and the ground becomes too great, a diffuse "spray" of mini-bolts radiates from the cloud. When one of the little leaders comes in contact with the ground, it becomes the main conduit through which the current flows. Because of the "inertia" or "momentum" (I put those words in quotes because I'm not sure they're technically applicable to electricity, but the idea is similar), too much charge moves between the cloud and the ground. The charge again becomes unbalanced, so the lightning bolt, which has started to dim, but is still the conductive tube of plasma (ionized air), allows the charge to move back again. This process repeats until the charge is essentially equalized; this is the cause of the multiple pulses of brightness.


The intertubes here at my favorite coffee shop were out from Thursday afternoon to yesterday afternoon due to the technical difficulty of the wireless broadcasting box thingy being unplugged. They don't have a technician on call, so they weren't able to fix the problem until an electronics engineer happened to hear me complaining about it. He managed to repair the device in under a minute, but it did require him to use most of what he'd learned in grad school, and in his many years of experience working at HP.

Factiousness aside, I've spent most of the last day catching up. Nothing has happened. Well, a war in Georgia- though I don't understand how the Russians got tanks to our southeast coast without anybody noticing. (If you read Pirarro today, you might want to put that Tour of Italy on hold.) And I guess the Chinese have taken the Gold in Olympic American Stabbing.- I don't follow sports and didn't even know this was an event, though I have to say I'm not really surprised. And let's see, I guess there was a great (unscheduled) fireworks display near Toronto, put on by a local propane supplier. It was right next to the airport and a oil refinery, and there as some talk initially that the show might have been sponsored by terrorists. But no, it was simply a gesture of corporate goodwill, or something. Not much going on.

So I went looking for stuff to make me laugh. I found a link to a great comic site, XKCD. Very geeky, nerdy. My kind of stuff. Lots of math gags, which is unusual in comics. Enjoy.

How to Pretend You Give a Damn About the Election

A number of the lefty bloggers I follow are getting sick and tired of this campaign. So am I. That's not to say I don't have strong opinions, nor that I feel it's unimportant. Commentators were warning late last spring- more than a year ago- that this cycle was starting much earlier than usual, and that fatigue amongst voters was inevitable. The Onion, in its long tradition of stinging satire, captures this feeling of exhaustion and adds a dash of apathy to unspice things up a bit.

Today Now!: How To Pretend You Give A Shit About The Election