Saturday, June 20, 2009


The meme lives... several more up at the home site!

Maglev Train: Now in Fun Size

I always assumed maglev technology would run on opposed electromagnets. This is an alternative I had heard of, but didn't really feel (to me) practical or economically feasible. This is very cool, kinda cute, and somewhat convincing... or at least intriguing. Of course, they don't discuss the composition and cost of the superconducting core, and scaling this up to human transport scale probably isn't feasible. For the time being.

Geeks and Nerds

I tend to stay away from longer videos; generally, I'd rather read for 15 minutes than watch a video for that period. But this is a good one: John Hodgman explains that most of our current problems are rooted in the ages-old conflict between the nerds and the jocks. It was kind of eerie how many of his quiz questions I could answer, and by his standards I am way out there on the nerd end of the spectrum. He ends on a rather touching and hopeful note. My only quibble is that it might have been even funnier if Obama had been miked.

Friday, June 19, 2009

Still Peckish

Hat Tip to Balloon Juice for image and idea. About Biafra.

Obama Opposes Biodiversity!

Can't quit. I can't believe the stuff that becomes "news." This one occured to me because I just murdered a fly that wouldn't stop pestering. Don't tell PETA. (Vidclip here)

Followup, June 20: Very funny response to PETA's nonsense at My Corner to Vent. (front page): "The fly kept landing on his hand. With the way that Obama talks with his hands..." You'll have to click over to read the punchline.

Glenn Beck Cries For an Hour

Pop Quiz over at MPS.

What I Think

Context here and here.

You Don't Say?

So are we done yet? No, we are not. Though we probably should move on to other things for a while.

Hoekstra Gets a Label!

Though as I've noted before, this absurdly grandiose blathering is so epidemic in the unhinged party as to be almost unnoticed, Hoekstra is now this blog's official poster boy of the phenomenon. As such, he has earned his own tag.
And don't forget to visit the orignator of this meme at for many more. They've just put up several more.

Hoekstra Meme Revisited

Context here and, and many more here.

My Robotic Avatar

Lifeform Optimized for Ceaseless Killing, Worldwide Observation and Online Destruction

Get Your Cyborg Name

I don't like the "Ceaseless Killing" part. I'll have to fix that...
Via Silver Fox.

Followup: Much better! (Font is 13 point "impact")

Thursday, June 18, 2009

Late-Week Geo-Meme: Show Me Your Sidewalk!

(Click for full size... which I just realized is quite close to its actual size!)

So what do sidewalks have to do with geology? Well, to begin with, they're made in large part of rocks; the other major component, cement, is man-made, and is therefore not technically rock. But perhaps more interestingly and importantly, gravel is used in very large quantities and is very massive, and thus is prohibitively expensive to transport very far. In consequence, nearly every community of more than a few people has its own source of gravel. That gravel in turn represents at least a few aspects of the local or regional geology.

In the case above, you can tell from the well-rounded pebbles that the gravel has undergone stream water transport. (Wave or current transport would result in the same rounding.) I have no doubt that this is from Willamette River fluvial sediments. Most of the Willamette gravels are derived from the west flank of the Cascade Range. There is some contribution from the Coast Range, but most of the Coast Range is underlain by grungy sedimentary rock that does not survive transport very far. If you look at the gravel in the Mary's river, which drains a substantial chunk of the Coast Range west of here, and has its confluence with the Willamette in the southern part of Corvallis, it is made up of almost entirely basalt. Additionally, the Coast Range component of the Willamette drainage is smaller and gets much less total precipitation than the Cascade component. So the above "random sample" of the rocks in my local drainage are not really random at all. It's dominated by Cascade volcanic rocks, and is further segregated in that rocks less resistant to weathering and erosion, those that don't survive transport, are either un- or under-represented.

Ranking from most abundant to least abundant we have
  1. Basalt- can be difficult to tell if it has been altered in this context. I look for a lack of polish.
  2. Altered volcanics- a broad and not entirely useful category, these are most often infused with some sort of microcrystalline quartz, such as chalcedony, or its non-fibrous analogues. The parent material is still the dominant component, but they have been hardened by the addtion of silica.
  3. Intermediate and Felsic volcanics- don't seem to survive transport too well unless they have been "altered," as above. Additionally, the Cascades are quite dominated by basalt; intermediate and felsic volcanics are simply not as abundant to start with.
  4. Jasper, agate and various other micro- and cryptocrystalline varities of quartz. These are fragments that crystallized in void spaces, so there is no "parent rock." Frequently in vivid colors, and take a nice polish from countless soles grinding on them.
  5. Petrified wood (technically for most fossil wood in the western Cascades, "permineralized wood," i.e. original woody material is still present, but has been completely infused and entombed in microcrystalline quartz)- probably belongs grouped with #2 or #4, but it's cool enough to warrent it's own bullet, IMHO.
So there you have it: a geo-literate person could walk a half dozen paces from the door of my favorite coffee shop and quickly infer quite a lot about his or her geological setting by looking at their feet (and btw, that's the toe of my boot for scale)... despite the fact that the closest "outcrop" is nearly a mile away.

So where do you live, geologically? Show me your sidewalk! I'm not going to tag anyone, unless no one plays...


(Full size here) This is certainly among the most amazing and stunning volcanic eruption images I have ever seen. According to the description of the image, "A fortuitous orbit of the International Space Station allowed the astronauts this striking view of Sarychev Volcano (Kuril Islands, northeast of Japan) in an early stage of eruption on June 12, 2009."

The plume of ash from this eruption has diverted numerous flights in the north Pacific region, and has forced quite a number to simply return to their point of origin; they didn't have enough fuel to safely divert around the plume. The blogger who brought this picture to my attention, Eric Klemmeti, has been following the eruption regularly under the category "Sarychev" on his blog, Eruptions. (Home page; the previous link will take you to all the posts of this volcano and its convulsions.)

Hoekstra Meme

"To Hoekstra is to whine using grandiose exaggerations and comparisons," according to the home site. This is a funny, funny meme that should not be (and in my mind isn't) limited to Pete Hoekstra; it's epidemic among the republicans. Hat tip to EB Misfit for pointing this out. (Followup: if you're not familiar with "napalm girl," here's the (in)famous photo. Warning: graphic and nauseating, though such an iconic image, might be considered safe for work. Or Not)

What I Think

Context here and here.

Wednesday, June 17, 2009


A kinder, gentler Jurassic Park, and a thousand points of "Hey!"
Catching up on my funny stuff..

Mount Doom

I frequently grab a picture from Cakewrecks for my Sunday Funnies. If you like to laugh, and you don't visit that site (sight) at least occasionally, you are missing out! This is the quintessence of cake wreckness, and much too entertaining to make it wait another four days...
Yes, they really did build that sweet disaster. Then, yes, they really did set it on fire. Visit the post for the full story...

What I Think

Context here and here.

No, I haven't abandoned this series, just busy and not particularly inspired by the recent "American Voices" posts... they haven't been bad, but my funny generator hasn't responded with anything postworthy.

And in a related note, I found this cool page hosted by the US Census bureau, which shows the real-time estimate for just how many of us there are in the US and the world...

U.S. 306,693,977
World 6,787,216,899
21:02 GMT (EST+5) Jun 17, 2009

Wednesday Words

Annnnd... it's Wednesday again! Thanks to last week's participants, who came up with some fun suggestions for additions to this crazy language we call English. I do have a few questions for you all... would this be more fun if I actually listed all the entries that came in for the previous post, or is the link back to the short post and comments enough? Would it be more fun if I withheld the comments until the next post, then put them all up at once? I know that sometimes I just feel, "Wow, there's no way I'm going to top that one!" then don't even try. How about voting on the suggestions? Just tossing out some ideas here... I'd like to get a few more folks playing. The two or three players we get each week come up with such great definitions, it seems there must be even more.

And with that quick quiz, here are this week's five would-be words:

Moral Obligation? US? Nah!

Suvrat Kher, over at Reporting on a Revolution, pointed out this NYT blogpost, and this Lancet article. The gut clenchers were these two cartograms. The first was large enough for me to make out, but I couldn't read the second, so I went to the Lancet article, skimmed over it, and captured the full-size images. I'm more than a little scared to read the full article, but I've downloaded it so I can, later, even if I don't have a wi-fi connection. (Click the pics for full size)
The top panel of the above image shows a cartogram in which the size of the country is a function of how much CO2 it has emitted; the bottom shows the estimated increase in mortality due to four climate-sensitive health factors: malnutrition, malaria, diarrhea, and inland flooding. (Follow-up: I suspect if you factored in some other climate-sensitive phenomena, such as coastal flooding associated with tropical storms, tornadoes and so on- and certainly if you factor in economic costs- the disparity would not be as extreme. Still, that's a stunning image)
This one shows "tipping points," where minor environmental changes could lead to positive feedbacks and runaway conditions with dire consequences. So, for example, the blob to the NE (~left) of Australia and SW of (~up from) North America is labeled "ENSO Triggering." ENSO stands for "El Nino- Southern Oscillation." El Nino an La Nina conditions have profound, and largely negative, consequences throughout the Americas. That little blob implies that these conditions would be more frequent and more severe. And it's just one of numerous blobs on the map.

Of course, what is the health and safety of a few hundred million people, when the profits of the megacorps might suffer? Burn, Baby, Burn!

Tuesday, June 16, 2009

Two of My Favorite Shows in 99 Seconds

Oh. My. God.
If this YouTube stuff had been around when I was a teen, I would have never discovered rocks. Good thing it wasn't around, but I feel bad for today's teens. (Hat tip to Swans on Tea)

Monday, June 15, 2009

Sunday Funnies: Monday Edition!

So some of my young friends have moved on for the summer, and some have graduated, and have moved on pretty much forever. It's a bittersweet time of year for me; I may see them briefly when they pass through town again, but we'll slowly loose touch with each other. On the other hand, they're so pleased to be done, and, rightfully, so proud of their accomplishments, and so eager to move on to the "real world" or graduate school, that it's impossible for me to be "sad" about it. (If only they knew the reality of either the real world or grad school... I enjoy saying, only a little facetiously, that the worst mistake I ever made in my life was applying for graduation.) But at any rate, to those newly minted graduates, and to those who've successfully defended recently (Yay, Amy! Yay, Ben!), I offer my hearty contragulations...
Sorry, Ian; I don't think we met, but I'm seriously hoping your life turns out better than that cake. Jen over at cakewrecks has been running disasterous gradcakes all week. This is one of my favorites. And what goes better with cake than a nice cup of freshly brewed coffee? What? Alright, who left the pot empty?

From here, via Buzzfeed. It's getting hot enough now that some nice cold water is a good alternative, though. Unless there's a hippopotamus in it. Or a dog pretending to be a hippopotamus; then it would be much too dangerous...
funny pictures of dogs with captions
see more dog and puppy pictures. And after all that food and drink, this week's emergent theme appears to be body functions. All you middle schoolers are going to love this weeks funnies.
From Saturday Morning Breakfast Cereal. Criggo is one of my favorite humor sites, where the tagline is "Newspapers are going away. That's too bad." So when I realized I didn't have anything from there in my lineup, I just had to go find something that fit the theme... this one does so admirably.
So this doggie would like you to desist from using gelatin desserts to ease the irritation:
(The title of this post was "I'm getting really sick of this nickname.") From Pets Who Want to Kill Themselves. And speaking of poop, I think I can say with a high degree of confidence that the last thing the world needs is a toilet that decorates...
engrish funny toilet decorates
(see more Engrish) ...and if I was to come across that sign, I would definitely take the advice of the following plan:
fail owned pwned pictures
(see more Fail Blog)

There are other body funtions, of course. For example, boogers...
(From Saturday Bulletin) ...and menstrual cycles, which have recently been shown to be susceptable to mathematical analysis: (XKCD)Then there are the bodies that function just fine, but underwent some quirky development. This young woman (I assume it's a young woman) seems to have taken it all in stride, with a cheeky sense of humor.
(From bmezine, this post. Front page here, but many posts NSFW; I think the name stands for Body Modification e-zine)

Rather than humor, this kitteh has reacted with rage at being implanted with a terminator eye.funny pictures of cats with captions
see more Lolcats and funny pictures

And this kitteh is shaken by what it has witnessed in today's "funnies" so far.
funny pictures of cats with captions
see more Lolcats and funny pictures

This little kitteh invented an entirely unique language...
funny pictures of cats with captions
see more Lolcats and funny pictures

...while this ketteh has merely expanded the definition of "black hole." Nothing that enters the box has a chance of escape.
funny pictures of cats with captions
see more Lolcats and funny pictures

Speaking of black holes, Pictures For Sad Children suggests they may be just wild and crazy parties at an atomic level:
What with budget cuts and all, I imagine many of you are being forced to economize. I hope you are not the one being economized! Have a good week at work, and try to keep in mind that however bad things may get, there's always a high probability they're going to could get much, much worse.
political pictures for your blog
see more Political Pictures

And make sure you keep up to date on all the relevant paperwork!
harrison ford and mark hamill
(see more Lol Celebs)

See you in the funnies!

What's Going On?

I've read hardly any news since Thursday; as you might have noticed, I just completed three substantial geology posts. I hear the Iranian election is thought by many to have been a farce, and there's some pretty serious unrest and response. Frank Rich has a typically terrific Op-Ed in yesterday's NYT regarding the silence of the "moderate" right in the face of the unhinged right's words and actions. Many of us liberals have been saying much the same thing for a while now, but as always, Rich's piece is better written and documented than most of us could ever hope to accomplish. Anything else I should know about?

There are probably a number of regulars here at my favorite coffee shop wondering where the Sunday Funnies are. I'm probably not going to get a whole lot of news read today either... I'd like to get up a Monday edition of the funnies.

In the meantime, drop me a comment or e-mail if they announce the world is coming to an end... I'd like to have time to kiss my ass goodbye.

Sunday, June 14, 2009

Accretionary Wedge: Let's Do a Time Warp!

Some are generic, but of the media-specific time-space transportation modes, how many can you identify? (9 different shows; click the pic to embiggen)
(Note: This is Accretionary Wedge #17; the original call for posts is here, and more Accretionary deliciosity can be discovered at the AW Home Page.)

(Note 2: If I've missed your post, or you have a late one you'd like added, leave a comment. The chronological order here makes it easy to wedge in more accretions)

Welcome! Come in! Have seat and make yourself comfortable. What? Yes of course there's room for more... it's much, much bigger on the inside than on the outside. No, you don't need a reservation. Beverages and dining are provided in the lounge, restrooms are around the corner there. The engineer assures me the nacelles are fully charged and purring like a kitten; shields are at full strength and functioning optimally. Lockers for sample and equipment storage can be found near the bay doors, behind the rovers. Downstairs, you'll find several square kilometers of laboratory space and some extremely sophisiticated analytical equipment. You're welcome to use whatever you need, but please do consult the manuals. The only injury that has ever been sustained during preliminary tests was when a young man misunderstood the use of the matter inverter, and suddenly found his insides outside, and outsides in. He claims it was very disconcerting to suddenly find himself staring at... oh, enough of that. He recovered, mostly, thanks to some quick thinking on the part of an assistant.

Now where was I? Oh yes, library upstairs, and this being a time machine, it's an extraordinarily complete library. You know that famous one in Alexandria that was burned? You have my word, the building was the only thing that actually caught fire; the writings are all upstairs. Yes, and full web access. You should see what's going to happen with the web in the second half of the 21st century... I'll just say the internet of 2009 seems positively claustrophobic by comparison.

You're welcome to wander where you please, but we recommend you stick within the areas described. We're actually not quite sure where this thing ends... we haven't completed the exploration yet, but there's growing suspicion that as people move toward an endpoint, new doors, corridors and enormous rooms open in response. It's very much like science: we often think we've found an end, when suddenly we discover more in front of us...

So are we set? Everyone comfortable? Have you introduced yourselves? Yes? I think we're ready. Make it So!


Our first stop will be a real test of our technology... before the big bang. I'm not sure of our location; it seems to be simultaneously everywhere and outside of everywhere. (Welcome to Outside the Interzone). It is very highly recommended that no one disembark at this time and location; Management cannot be held responsible for accidental universes or their inhabitants. The viewing panels in the lounge are open to their fullest extent. Jazinator will lead the examination of either a former universe or singularity.

Time: 14+ Ga
Location: here, there, and everywhere
I would like to go back, not to the Big Bang (which I would assume several scientists would love to marvel at) but before it (maybe a few billion years, give or take). What came before the Big Bang? Was there just a singularity sitting there for all eternity or was the previous universe collapsing in on itself?

Wouldn't God know better than to use a carpenter's hammer on lithic material?

This is one of the stops that pretty much every science-oriented person in the world daydreams about now and then. Bob Jamieson is going to lead a search for the origin of life. Apparently our first stop is in France, but this one is worth the time it will take to track down, where ever the location turns out to be...

Time: ~3.5-4 Ga
Location: first excursion, France (see picture)
Somewhere in the vicinity of 3.5 Billion years ago (give or take a few hundred million years), in a puddle of goo struck by lightning (probably), life formed. Our knowledge about this event is understandably very very shaky, due to both the distance back in time, and the lack of preservation of the kind of biological activity we’re interested in. The rock record isn’t very useful here; past a certain point too much has been metamorphosed, and organic molecules broken down too much to be informative.
France, ~3.5 Ga

Bryan at In Terra Veritas has an ambitious excursion planned for us; we're going to do a comparison of the early tectonic styles of Venus, Earth and Mars:

Time: ~2 -4 Ga
Location: All over the Earth-like planets
I think I will take advantage of the non-limitation to Earth clause and couple that with the time-lapse clause. It might be fun to observe how Martian tectonism quieted down over time, and collecting data from that event would advance our current understanding of tectonics and planetary geology. We know that Mars has been, for all intents and purposes, tectonically quiet for quite a while.
As they are today...

Chuck at Lounge of the Lab Lemming steadfastly refuses to give details, but there's something he wants to show us at about 2 Ga.

Time: ~2 Ga
Location: Maybe he'll tell us when we get there
So, there’s no *If* about it. I time travel every day. The thing is, so do most geologists. That’s what we do. Geology is a type of investigative reporting where we piece together stories from hundreds of millions of years ago by extracting eyewitness accounts from whichever rocks happened to be witness to the events that interest us. Being a dastardly sort of geologists, I simply do this by torture. I stick the rocks in a steel chamber, suck the air out, and then blast them with an ion beam until they talk.

Kim at All My Faults are Stress Related shows us around a late paleoproterozoic environment as the Vallecito Conglomerate is deposited; respirators are highly recommended if you choose to disembark.

Time: ~1.7 Ga
Location: Weminuche Wilderness, Colorado, USA
This is the Vallecito Conglomerate. It's been metamorphosed, but its sedimentary features are still preserved. It's got big clasts, mostly of vein quartz and banded iron formation, and big trough cross-bedding. It's only found in a small but spectacular part of the Weminuche Wilderness, although there are similar rocks in other places from around the same time. And this one is at least a couple thousand feet thick.

Our next stop may (or may not) involve some interesting chemistry; leave your respirators on until we can determine whether the atmosphere can support large fauna like ourselves. Hypocentre will be our guide here...

Time: ~540 Ma
Location: Caerfai Bay, Wales
I’d like to travel back to the Lower Cambrian to answer the question – “Why is this rock red?” (...) So, we have a major change in sea water chemistry. We also have the ‘Cambrian Explosion’ occurring at precisely that same time. Up to this point in the Cambrian we have the ’small shelly fauna’ but it is now that the triboltes and echinoderms kick in. This surely cannot be a coincidence.
Caerfai Bay Shales

A time traveler who has been galavanting about on his own, Graham at Ancient Shore, was pointed out to me just a few days ago. As I was reading through his memoirs, this post jumped out, begging to be a part of our odyssey: a visit to Ordovician islands, and possibly a gourmet meal...

Time: ~450 Ma
Location: Churchill, Manitoba, Canada
Churchill may be a unique, lonely place today, but on my Ordovician island it is far lonelier – for it is silent except for the waves lapping on the shore. The silence is occasionally disturbed by tropical thunder, and rarely by giant hurricanes driving monstrous waves and huge boulders against the shore. There are no gull cries, but the smells may not be all that different – no doubt there is rotting seaweed on the Ordovician shores, too. (...) Every time machine should be stocked with nutcrackers, bibs, and a supply of melted butter.
Ancient islands on the shores of the Hudson Bay

I'm thinking it sounds like Volcanista needs a big hug, and a big mug of cocoa, or mocha or something. She just sounds so gleeful as she contemplates our current stop, the mass extinction that has topped (so far) all the others: the Permo-Triassic.

Time: ~251.4 Ma
Location: We'll figure that out when we get there
I want to see a mass extinction — a big, catastrophic, geologic-record-punctuating event. The formation of the moon would be really fun, too, but it’s not as controversial anymore (to most people). There are still poorly-understood mass extinctions — in particular, the biggest one of them all: the P-T. I want to see who’s right and who’s wrong, and I want to see what happened, all for myself.
(Not the P-T impact, but even nastier)

Julia, the Ethical Paleontologist, is going to give us a tour of the real Jurassic Park, then we'll lounge around and drink pina coladas, or whatever tropical drinks strike your fancy...

Time: ~165 Ma
Location: The Cotswolds, England
So the first thing I'd do would be to whack on some SPF30, because everyone who works on British geology says "It was like the Caribbean", so there's a good opportunity to combine Serious Research with taking the edge off my Northern European pallour (fearsome predators permitting).
By Doug Henderson from this website

Lost Geologist plans on stopping at the creation of a fascinating ore body... incidentally, LG was the blogger who pointed out our fellow passenger from the Ancient Shore just a few days before we set out on this magical mystery tour.

Time: Sometime between Permian and Tertiary; we'll narrow it down on site.
Location: Silesia, Poland
I want to be there while the Silesian Mississippi Valley Type district forms. This is not only the largest MVT Pb-Zn district of the planet with 730 Mt of ore but also there is evidence that the largest district of its kind was formed in an increadibly short amount of time! In the hypogenic karst cavities of the Silesian deposits you can find speleothems (see image) growing up and downwards. The point is they don't grow vertically up and down - they show indication of growing into the direction of fluid flow
Sulfide speleothem from the Olkuze mine
(Source: Scanned from Conference handout SEG workshop on the Geology of Pb-Zn Ore Deposits, Lima, Peru, 2008. Image from chapters of David Leach)

Ikenna of Nigeosyncline has popped in a bit late, but hey, if a time machine can't make provisions for late participants, what good is it? He wants to examine the Cretaceous seas of Nigeria (actually, he wants to watch the whole history of the area, but is particularly eager to see the evolution of the Benue trough).

Time: Cretaceous
Location: Benue trough, Nigeria
Actually if I had a time machine I would go through the whole of geologic time on the spot where I’m on (Nigeria) to see how the land I live on has changed through time. But to narrow down I’ll go for the cretaceous when the Benue trough was evolving. there are still a few important questions to be answered:
  • Is the Benue rift a failed arm of an R-R-R triple junction formed at the early stages of the opening of the Atlantic (similar to the red sea-afar triangle) or is as a result of transcurrent movement along the chain and chacourt transform faults?
  • How extensive were the various trangressions in the area? Did all transcontinental connections between the Tetys and the Atlantic exist?
  • What caused the Santonian compression and it’s accompanying magmatism?
Where I'm talking about, 120 million years ago

Garry Hayes has been time traveling for a while; so much so, his blog is called "Geotripper." His choice, as best as I recall, is about 5 Ma, in northern Arizona. He wants to show us the origin of the Grand Canyon:

Time: ~5 Ma
Location: Grand Canyon, northern Arizona
A separate drainage system related to extensional stresses to the southwest evolved which eventually captured the river, and from there the giant canyon was carved in just a few million years. I have many times imagined seeing that first trickle of water that spilled over the low divide, and how it would have become a torrent, and within hours the work of building a new canyon would have begun.
Coconino at Ordinary High Water Mark wants to tour a wetter environment than the current arid climate of the southwest US... she is going to (along with Anne, next) guide us through the Missoula floods, and the contemporary pluvial lakes that so dominated basin and range during the glacial intervals.

Time: ~19 Ka to ~12 Ka
Location: Montana, Idaho, Washington, Oregon and California, USA
The repeated Missoula floods (potentially 40+, from the varve-like slackwater deposits in southeastern Washington called the Touchet beds) carved out the Channeled Scablands of eastern Washington. The lakes, coulees, and river channels of the scablands were carved by the massive floodwaters (up to 500 cubic miles) that occurred repeatedly through the Pleistocene. They were identified in the 1920's by Harlan Bretz, who was derided as the flood theory of scablands creation just didn't mesh with the theory of uniformitarianism.
An extraordinary sight: a lake in Death Valley! (visit the post for glorious full-size)
Chris Rowan Guest blogger Anne Jefferson at Highly Allochthonous also takes us on a mountains-to-the-sea tour of the Missoula megafloods. Swimming is strongly discouraged; the water is most definitely not fine. I frequently suggest to my friends here in my little burg to imagine 150 feet (~50 m) of water... with icebergs, no less... inundating their familiar stomping grounds. It really wasn't that long ago, and I'm pleased to have an opportunity to visit my home 19 Ka before I was born.

Time: ~19 Ka to ~12 Ka
Location: Montana, Idaho, Washington and Oregon, USA
A little after 19,000 years ago, water in Glacial Lake Missoula ruptured the ice dam, and the collected water went rushing downstream at speeds reaching 100 km/hr. Peak discharge in the Spokane Valley has been estimated at 17 +/- 3 million cubic meters per second, and drainage of the lake took several days.
Figure 3. Dry Falls and Grand Coulee near Coulee City, Washington, June 2004. The falls are 122 m high and 5.6 km wide. Photo by the author.
Dave Bressan at Cryology and Company is in charge of the next stop, as he examines life recolonizing Europe after a kilometer or so of ice finally melted, and the long, long winter finally came to an end...

Time: ~18 Ka to present
Location: Southern Tyrolean Alps, Europe
10.000 to 18.000 years ago the great glaciers retreaded for the last time, uncovering a barren landscape, lacking vegetation cover. The basins carved by the glaciers where filled by time with water and mud, transported by rivers still feeded by small glaciers. This mud will form the grey clays. Still more time passes, the climate is warmer, the last ice melted, and the basin now is a lake surrounded by dense forests. One day of 11.000 years ago suddenly a black cloud covers the sky, and a fine, grey dust falls on the lake, where it sinks to the ground and deposits. Some hundred km distant from the lake the Laacher See Volcano erupted, covering half Europe with a small band of distinctive, grey ash.
If I can work these controls right, this one will feel like an elevator ride. Keep your mittens and parkas handy... Chris M. at Pools and Riffles is going to show us through the post-glacial rebound in northeastern Canada. Incidentally, if I had been asked to guess which locations might come up two or more times in our itinerary, Hudson Bay, the only specific location that did, would not have been among my choices.

Time: ~10Ka to present
Location: Hudson Bay, Canada
The geologic event I choose is the isostatic rebound of the Hudson Bay region. At the end of the Pleistocene and the beginning the Holocene, the massive ice sheets covering northern North America began to melt. As the weight of thousands of meters of ice over the Hudson Bay region was removed, the surface began to rise.

As the land continued to rise, new shorelines were repeatedly being formed, as the old shorelines were elevated higher. In some places, over 175 old shorelines ring the present bay level. This is equated to over 300 m over rebound in places. And it is still rising.

As we return to near our own time, Callan Bently at NOVA Geoblog wistfully asks that we stop and look at what we've lost in such a short period of time:

Time: 518 years before present day
Location: Northern Virginia, Washington D.C.
I want to see a vibrant ecosystem with big trees. I want to see the water of the Potomac River look like water; I want to go swimming in it. I want to see what bird migration looked like before it dropped off so precipitously. I want to see a passenger pigeon, a carolina parakeet. I want to see for myself what a healthy amphibian population looks like. And bison fording the Potomac in Alexandria...

...And, once I've seen that former world, I can't guarantee that I'd come back.

Late Addition: One of the nice things about my other pair of shoes being a time machine is that it's easy to pick up folks who were otherwise engaged at the original departure date. Julian over at Harmonic Tremors offers an extraordinarily human take on a recent geological event. Human in the sense that he is as interested in the people, or more so, as he is the event itself, the 1906 San Francisco earthquake:

Time: April 18th, 1906
Location: San Francisco, California
I'll admit right out that I am curious what it feels like to be in a M7.8 earthquake. So far, my personal experience maxes out at M5.4, which was entirely exciting and not at all terrifying in my book. I suspect M7.8 would be well past the boundary between excitement and fear... (...) I would be so excited to watch the faults of California get drawn in on the map for the first time, outlining mountain ranges, bounding geologic provinces, highlighting the network of hazard that we still strive to understand and mitigate today. And to be able to witness that while also observing the rebuilding of San Francisco...Definitely a time of wonder and excitement, even though it came out of tragedy.
Looking southward from San Francisco along the San Andreas Fault. Picture from here.
Silver Fox at Looking for Detatchment has planned an outing sometime in the not-too-distant future, but bring your hard hats and asbestos undies...

Time: We'll find out... perhaps a few centuries to a few 100 Ka in the future.
Location: Yellowstone, NW Wyoming, or maybe Long Valley, central Eastern California
Now we jump into the unkown future, and we are able to see the exact unfolding of the next large-caldera-forming eruption at Yellowstone. We are finally able to answer our many questions. When will the next caldera at Yellowstone erupt, how long will the eruption take, where will the ash flows flow, how thick will they be, and how hot? Will we all be on Mars or orbiting in space so we won't be wiped out? Where exactly in the developing Snake River Plain will the caldera form, will the magma come through Yellowstone Lake thus making the normally and hugely explosive eruption even more explosive? These are some of the many questions that occur to me when thinking of the Yellowstone area. I'd prefer to watch this sometime in the distant future, and not too soon on any human scale.
Potts Hot Spring, West Thumb Geyser Basin, Yellowstone National Park. NPS photo by J Schmidt, 1977.

Last stop! I ( in the post after this one) want to see what's going to become of my home ground over the next few 30 to 40 Ma...

Time: +30-40 Ma
Location: Western North America
I want to see what's going to happen with Basin and Range in western North America. Will North America remain a single block as Basin and Range spreading subsides? Will a single subcontinent break off and beome a Texas- or Alaska-sized island heading off to the northwest? Or will this region, composed of numerous terranes stitched together over the last 70-80 million years, break up and form a new generation of lithospheric ships, drifting independently on a Mohorovičić sea?
Tear along the perforated lines?
So that winds up our field trip through time and space for this month, a pleasant, day-dreamy jaunt that was just perfect for an early summer excursion. As several geobloggers pointed out, this is what we do in this discipline... we cobble together the bits and pieces of evidence we can lay our hands on, then build a case for the reality of a world that previously has existed only in our imaginations. There is a real value in day-dreaming, and this was a fun one.

My sincere gratitude to all the wonderful geobloggers that participated; I had a great time putting this together, and I couldn't have done it without your work. Mistakes are my own, and I reserve the right to edit ones that embarass me. I also reserve the right to add late submissions, if any come in.