Stories tagged Forces of Nature

Oct
30
2009

For me, the greatest mystery in the universe is Lindsay Price, and how she continues to find work.: Not that great a mystery, I guess…
For me, the greatest mystery in the universe is Lindsay Price, and how she continues to find work.: Not that great a mystery, I guess…Courtesy catechism

And, let’s face it, who hasn’t had the urge now and then? At the “Quantum to Cosmos” physics conference in Waterloo, Canada, seven physicists were asked, "What keeps you awake at night?" (Apparently, they meant “what issue in science” as opposed to love, money, or lack thereof.) The panel came up with some pretty heavy questions:

Why are the fundamental laws of nature the way that they are? There doesn’t seem to be any reason why they couldn’t be some other way. Are there, perhaps, other universes with other rules?

How does the Observer Effect work? This is a little deep for me, but apparently at the sub-atomic level, simply observing a particle over here can effect another particle thousands of miles away. How does nature do that?

What is the nature of matter, anyway? Especially the “dark matter” which is theorized to exist in outer space, messing up all our gravity calculations.

On a related note, will string theory ever be proven? String theory is the latest theory for how matter and energy interact at the sub-sub-sub-atomic level. And while it is very elegant and seems right on paper, no one has any idea how to conduct an experiment to prove or disprove it.

How do complex systems arise out of simple, basic particles and forces? You know, complex systems. Like life, the universe, and everything.

How did the universe begin, anyway? Physics can only take us back to a few fractions of a second after the Big Bang, a moment at which the universe was very small, very hot, and very dense. Before that, the laws of physics break down. No one knows how to describe the Bang itself, or how / why it happened.

Which brings us to, what are the limits of science? Science is based on observation and experiment. But, at some point, you run into ideas that can’t be tested. In theory, it’s entirely possible that there are other universes. But we’re stuck in this one—how would we ever know?

If anyone has answers to any of these questions, please send them to Canada ASAP. It sounds like there’s a bunch of scientists up there who could use a good night’s sleep.

Sep
10
2009

Pshhhheeeewww!: Science everywhere!
Pshhhheeeewww!: Science everywhere!Courtesy SiamEye
I don’t even know where to begin today! All I can think is “OMG!!!!” And each exclamation point I think is like a blood vessel bursting in my brain!

OMG pop pop pop

So why is this a day of excitement, instead of quiet family tragedy? Because the biggest explosions today aren’t happening in little tubes in my head, they’re happening in the world of science! (I don’t consider the physiology of my head to be science. More like magic. Or trial and error.) I just don’t know what to do with all this science.

See, unlike your average Friday Extravaganza, a Thursday Explosion has no focus; it’s just kind of all over the place. A mess! There are all these stories, but we really have to stretch to fit them into a single post… so the loose theme of this explosion will, fittingly, be “flying things.” Am I not helping? Just wait, you’ll see.

Normal mouse becomes flying mouse, doesn’t care!
Check it out: a baby mouse was put into a little chamber and subjected to an intense magnetic field. What happened? All the water in the mouse’s body was levitated. And because those squishy little mice are so full of water, the mouse itself levitated along with the water.

Unfortunately, the first mouse wasn’t quite ready for life as an aviator, and upon levitation, he began to, as scientists say, “flip his Schmidt.” Lil’ mousey started kicking, and spinning, and with minimal resistance in the chamber, he started spinning faster and faster. He was removed from the machine, and put wherever little mice go to relax. Subsequent floating mice were given a mild sedative before flying (pretty much the same thing my mom does), and they seemed cool with it. Now and again the floating mice would drift out of the region of the magnetic field, but upon falling back into it they’d float right back up. After remaining in a levitating state for several hours, the mice got used to it, and even ate and drank normally. Afterwards, the mice had no apparent ill-effects from the experiment (rats had previously been made to live in non-levitating magnetic fields for 10 weeks, and they seemed fine too.)

Aside from the excitement normally associated with floating mice, the experiment is promising in that it may be a useful way to study the effects of long term exposure to microgravity without bringing a subject to space.
pop pop pop

Great tits are dangerous if you’re a sleepy bat!

It’s true! Forget everything you thought you knew about great tits and get schooled once again, my friends, for great tits are killers!

I’m not talking about the senseless murder of bugs, either—everybody already knew that great tits are primarily insectivores. A population of great tits in Hungary have been observed hunting bats!

As fun as it is to keep writing “great tits” with no explanation, I suppose we should be clear that great tits are a type of song bird common in Europe and Asia. Little, bat-hunting songbirds.

Meat eating great tits had been reported in other parts of Europe, but it was thought that those individuals had only consumed already-dead animals. The tits of Hungary were actually observed flying into bat caves, where they would capture tiny, hibernating pipistrelle bats and drag them out of the cave to devour them alive. It even appeared that the birds had learned to listen for the bats’ disturbed squeaking (or, as I like to think of it, their horrified shrieking)—when the same noise (which is too high for humans to hear) was played back for captured tits, 80% of the birds became interested (read: bloodthirsty) at the sound.

If it really is just the Hungarian population that engages in this behavior, the situation also brings up the possibility of culture in the birds. That is, if this isn’t some sort of innate behavior, but something learned and taught, and passed through generations that way, it could be considered culture. Amazing! Great tits are cultured!

pop pop pop

Flying velociraptors!

Well, not so much flying as falling. But falling with purpose. (What was it Buzz Lightyear said? Oh yeah, “I’m so lonely all the time.”)

We all know about how awesome raptors are. I think it’s part of kindergarten curriculum now, just between how not to accidentally poison yourself, and why you shouldn’t swear and hit. Well, I remember reading a news item a couple years ago about how some paleontologists were thinking that raptors’ famous giant toe claws may not have been for disemboweling their prey. Instead, the scientists proposed, raptors would lodge the massive claw into the skin of their prey with a kick, and then use it to hang on to the unlucky animal while the raptor went bite-crazy. The researchers had made a simulation of a raptor claw, and found that it could easily puncture thick skin and flesh, it didn’t seem to be sharp enough to actually cut the skin. (Cutting is necessary for a good disemboweling.) One might argue over the strength and sharpness of raptor claws, considering that the fossilized bone claws we see in museums would have been covered with a tough, horny substance, which did not fossilize, but whatever—the new scenario was still pretty cool.

Now, the same group of paleontologists is proposing that raptor claws were also well suited to tree climbing. Raptors could have waited on overhanging limbs, and then pounced on their prey from above. Pretty neat! The researchers point out that the microraptor a tiny relative of the velociraptor, had feathered limbs to help it glide down from high places, so it’s not a stretch to think that its cousins were comfortable in trees too. “The leg and tail musculature,” one scientist says, “show that these animals are adapted for climbing rather than running.”

I’ll take his word for it, I guess, but I do have some questions on that point. There’s a dromaeosaur (it looks a lot like a velociraptor) skeleton here at the museum, and I seem to remember that its tale was supposed to be very stiff—it has these cartilage rods running the length of the tail to keep it rigid. I feel like a long, stiff tail would be a pain in the butt up in a tree. It’s not the sort of thing arboreal animals invest in these days. Also, I wonder what sort of vegetation was around in the areas raptors lived. Plenty of big trees with good, raptor-supporting limbs? (I’m not implying that there weren’t, I’m just curious.)

The researchers do acknowledge that tree climbing wouldn’t have been every raptor’s cup of tea, however. Species like the utahraptor, weighing many hundreds of pounds, and measuring about 20 feet in length would have been “hard put to find a tree they could climb.”

pop pop pop

Pretty neat stuff, huh? Explosions usually are. But you see now why I couldn’t wait for three posts to get it all out there.

Sep
08
2009

Trailhead sign
Trailhead signCourtesy Mark Ryan
In the latter days of summer my wife and I took a drive up the Gunflint Trail and visited the Magnetic Rock Trail, a spur trail jutting off the Gunflint near Gunflint Lake. Our original plans of lounging about the North Shore of Lake Superior had been scuttled by a mix-up in our cabin reservations, so I saw it as an opportunity to check out first-hand some of the local geology. I had visited the MRT briefly once before and my reasons for wanting to make the 50-mile drive from Grand Marais to revisit the trail were three-fold: stromatolites, meteorite impact ejecta, and, of course, magnetic rocks

Well, as it turns out, I wasn’t very successful,

Signs of recent fire: Evidence of forest fire can still be seen along the Magnetic Rock Trail.
Signs of recent fire: Evidence of forest fire can still be seen along the Magnetic Rock Trail.Courtesy Mark Ryan
Readers may recall the Ham Lake forest fires raged along the Gunflint Trail in the early summer of 2007, destroying several hundred acres of the surrounding forest along with resorts and private property. The fire, it was later determined, was started by a legal campfire in the vicinity of Ham Lake that had gotten out of hand and spread quickly through the region. It was the second forest fire to rage through the Magnetic Rock Trail (MRT) in the past two decades (there was also a controlled burn in 2002). The latest fire removed much of the pine canopy that covered the area, opening it to more sky and sunlight, and new vistas of the surrounding terrain.

Idyllic scene at a pond along the Magnetic Rock Trail
Idyllic scene at a pond along the Magnetic Rock TrailCourtesy Mark Ryan
A new jack pine rises from the ashes
A new jack pine rises from the ashesCourtesy Mark Ryan
But as destructive as forest fires can be, they do have their upside. Forests are quick to revitalize after fires. New trees soon rise up from the ashes, and evidence of that in the MRT was apparent in the many jack pines (Pinus banksiana) we saw sprouting up everywhere. But trees aren’t the only affected flora. A lot of the groundcover gets incinerated as well, sometimes exposing patches of bedrock. In the case of the Magnetic Rock Trail, it meant new outcrops of the Gunflint Iron Formation were uncovered, revealing fresh unexplored exposures.

The Gunflint Iron Formation is a mass of iron ore taconite that spans from the Arrowhead region of Minnesota eastward into Ontario, Canada with the majority of the formation located on the Canadian side of the border. Most iron formations on Earth were formed around the same time, about 2 billion years ago during the Middle Pre-Cambrian (Early Proterozoic) times. A shallow sea (the Animikie) covered much of northern Minnesota and eastern Ontario at the time. The sea teemed with cyanobacteria in the form of stromatolites; thick microbial mats that helped oxygenate the Earth’s atmosphere and metabolize iron out of solution through photosynthesis. The iron-oxide sediments later became the iron ranges that span across northern Minnesota and Canada. Much of the rock along the Magnetic Rock Trail is composed of magnetite (Fe3 O4) inter-bedded with layers of chert or shale. Magnetite is the most magnetic of all the naturally occurring minerals, hence its name. The Gunflint Iron Formation is particularly resistant to erosion on the Minnesota side probably due to its nearness to the Duluth Complex intrusives. These influxes of magma moved into the area around 1.1 billion years ago, adding tremendous heat to the existing strata. The portion of the Gunflint Iron Formations (that located in Minnesota) closest to the heat source shows the most resistance to erosion.

Stromatolites and not?: Stromatolites by geologist Jim Miller, MN Geological Survey (top); maybe not stromatolites by author (bottom)
Stromatolites and not?: Stromatolites by geologist Jim Miller, MN Geological Survey (top); maybe not stromatolites by author (bottom)Courtesy Jim Miller, MN Geological Survey (top) Mark Ryan (bottom)
Preserved within some of the newly exposed outcrops along the MRT are fossil records of these stromatolites, representing some of the oldest fossils found in Minnesota. Gunflint stromatolites contain large numbers of fossils that can be seen under a scanning electron microscope. I had been told that you can walk off the main path and find some of these ancient fossils, so I searched off-trail for a while and found what I thought were stromatolites, and took photos of them.

But later when I consulted with geologist Mark Jirsa, he wasn’t so sure.

“You're looking at thin bedding in the iron formation that dips shallowly in comparison to the dip of the outcrop surface,” he wrote me. “The result is a swirly look, that looks deceptively like stromatolite mounds.”

Jirsa was in the field when I contacted him, and his Internet capability was limited, so when he tried to send me some photos of what the stromatolites actually looked like, they didn’t come through. However, his colleague, geologist Jim Miller (who also supplied welcomed assistance with this post) sent me a stromatolite photo he had taken at MRT.

Personally, I can’t tell the difference, but then I’m no geologist. so I have to bow to the professionals.

My second quest – to locate and photograph ejecta from the Sudbury Impact – wasn’t successful either. The aforementioned Mark Jirsa discovered this record of a 1.85 billion-year-old meteor impact in 2007. I wrote a previous post about it that same year so I won’t go into those details (you can read it here) but I will bring you up to speed on how he’s since interpreted the find.

Briefly, the Sudbury Impact Crater is located in Ontario, Canada, and was made by a meteorite about 10-miles in diameter that slammed into the Earth 1.85 million years ago. The 150-mile wide crater is the second largest known on the planet. The collision sent a tremendous firestorm of superheated material into the atmosphere, and some of it coalesced like hailstones and landed 480 miles away in northeastern Minnesota. This is what Jirsa discovered two years ago: a layer of ejecta mixed with torn up pieces (breccia ) of the Gunflint Formation, and all of it overlain by a younger layer of slate known as the Rove Formation. He published an article about it in Astronomy magazine, and there’s also a PDF file downloadable from Minnesota Geological Survey website (the link is located in the upper left of the MGS homepage).

Debris from Sudbury Impact found in Minnesota: Photo by Mark Jirsa, Minnesota Geological Survey
Debris from Sudbury Impact found in Minnesota: Photo by Mark Jirsa, Minnesota Geological Survey
What Jirsa found was quite remarkable: a layer of churned-up rocks laid down above the Gunflint Iron Formation. The odd jumble of rock included berry-shaped rocks known as accretionary lapilli, intermixed with the Gunflint Iron Formation rock. According to his interpretation, what is seen in the layer essentially shows the events of a single day in the geological record. And a nasty day it must have been.

Three minutes after the initial fireball impact at Sudbury, seismic waves from earthquakes measuring more than magnitude-10 on the Richter Scale reached the Animikie basin, ripping loose the iron formation off the seafloor crust, and redistributed it along a submarine slope. Within 10 minutes, a firestorm of molten material hailed down from the sky covering the region with from 3 to 10 feet of ejecta in the form of accretionary lapilli. Ultra-hurricane-force winds measuring up to 1400 mph(!) blasted over the shallow sea soon after, followed by the coup de grace – titanic tsunamis the likes of which have never been seen since which tossed everything into a stew of breccia (jumbled rock) and berry-shaped ejecta.

This day of horror took place sometime in the 48 million year interim that separates the Gunflint Iron Formation and the time the sediments of the Rove Formation were laid down above it. The entire concoction was later baked and metamorphosed by the intrusive magmas of the Duluth Complex.

How hard could it be to find evidence of a mess like this? Well, considering the MRT covers a large area, and since I had no information pinpointing any locations, it was like looking for a needle in a haystack – a very large haystack. In the end, I soon gave up because I really didn’t know what I was looking for and I realized how futile it probably would be. However, I’ve sure learned a whole lot about it now.

Magnetic Rock Trail's rocks are magnetic: as my handy magnet proves.
Magnetic Rock Trail's rocks are magnetic: as my handy magnet proves.Courtesy Mark Ryan
Initially, I thought at least my third quest – finding magnetic rock – would be a complete success because just about every rock exposed along the MRT is highly magnetic (I had a magnet with me and I can attest to that fact – see photo). It made sense that the whole reason the trail is called the Magnetic Rock Trail is because of all the magnetic rocks found there. But I’ve since learned I was once again totally wrong. The trail is name after a single large magnetic rock that’s about 1.5 miles up the trail. This 30-foot monolith stands upright and obvious in the middle of the forest and its notoriety dates back to early native American times. It is a chunk of the Gunflint Iron Formation – and highly magnetic like the rest of the rock in the area – but is deemed an erratic moved into place from a short distance away by glaciers during the last Ice Age. Had I read any of the brochures I had collected on our trip sometime other than when I got home, I would have known this before I even got there. But as it was, we didn’t walk that far into the trail so we missed it completely. Oh, well.

Blueberry picking: Mrs. R collects blueberries near the Magnetic Rock Trail.
Blueberry picking: Mrs. R collects blueberries near the Magnetic Rock Trail.Courtesy Mark Ryan
But even though my three main objectives for visiting the MRT were pretty much complete washouts, there was one unexpected surprise that will probably draw us back to the region next year: blueberries.

Blueberries and metamorphism: The real attraction at the Magnetic Rock Trail?
Blueberries and metamorphism: The real attraction at the Magnetic Rock Trail?Courtesy Mark Ryan
Wild blueberries (Vaccinium angustifolium) were all over the place. The low-bush berries thrive in sandy, acid soils of forest clearings, and in rocky areas around pines forests – just the type of environments you find around the MRT. So, once I finished with my failed geological studies, I assisted my wife in picking as many wild blueberries as we needed. We kept them in our cooler for the ride home, and as Mrs. R is prone to do, she jumbled all the berries together into a viscous concoction, all within a flakey crust that was heated over time at a very high-temperature.

The result looked something like the Sudbury Impact ejecta layer found near the Magnetic Rock Trail, but it was much more delicious, and a great way to end the summer.

ADDITIONAL LINKS
Forest regrowth on Buzz
More about stromatolites
Top Ten Most Impressive Impact Craters
More about Minnesota geology

Sep
01
2009
...any Bad Religion fans out there? Oh nevermind. The daily feed from NASA's MODIS Aqua satellite has some cool images of the Los Angeles wildfire. It's shocking to see how close it is to the city. You can follow the images as the fire progresses on the MODIS website for the LA area. Double click to zoom in below:
Aug
05
2009

This year has been designated The Year of Science 2009, and the theme for the month of August is weather and climate. What better way to celebrate than to dust off one of my old videos and show it again on the Science Buzz blog. I shot the video over Lake Harriet when one of those typical thunderstorms rolled through Minneapolis a few summers ago. We're obsessed with weather here in Minnesota, and I'm particularly crazy for thunderstorms!

If you want more information about this month's theme you can find it at the Year of Science website.

Aug
05
2009

Somewhere, beyond the sea: Somewhere, a plastic continent that you're missing out on.
Somewhere, beyond the sea: Somewhere, a plastic continent that you're missing out on.Courtesy teapic
Pack your bags, Buzzketeers, because you don’t want to be the last person to make it to the world’s newest, creepiest continent. (Don’t worry, Australia, I’m not talking about you.)

Trashlantis! The new frontier! The Texas-sized plastic layer floating in the middle of the Pacific Ocean! Why would you not want to go there? The answer, of course, is that you wouldn’t not want to go there… ever!

Yet another scientific expedition is on its way to the fabled plastic continent. But while the last group of researchers mentioned on Buzz was at least partially motivated by the potential to turn Trashlantis back into some more useful hydrocarbons, it looks like these folks are more interested in seeing how the plastic is affecting sea life.

The Yahoo article linked to above sums up the expedition with:

”The expedition will study how much debris -- mostly tiny plastic fragments -- is collecting in an expanse of sea known as the North Pacific Ocean Gyre, how that material is distributed and how it affects marine life.”

I’m guessing what they’re getting at has to do with how plastic affects very very small organisms as it photodegrades. We understand how chunks of plastic in the ocean are no good for larger animals—marine life can choke on them, or fill their stomachs with trash—but the problem goes further than that. See, eventually those larger pieces of plastic start to photodegrade. (That means they get broken down by the energy in sunlight.) But photodegredation doesn’t seem to actually get rid of the plastic, it just breaks it into increasingly smaller pieces. When a plastic bag turns into a million little tiny chunks, it no longer poses a risk for, say, a sea gull choking on it. But smaller organisms are still likely to gobble some up, and if they can eat anything bigger than they can poop (it happens), they’re in a lot of trouble. And when small organisms die off, so do the slightly larger creatures that eat them, and the larger creatures that eat them, and so on. (You remember this from grade school.) So how will Trashlantis fit into this plasticky food-path?

And then there’s the huge real estate potential for Trashlantis. So get there now.

Jul
31
2009

Feeling a little frayed?: That's ok. We've been jerked around a lot in the last year.
Feeling a little frayed?: That's ok. We've been jerked around a lot in the last year.Courtesy KinnicChick
Ok. The startup of the Large Hadron Collider, the biggest, fanciest machine ever built, the doomsday atom-smasher, the revealer, the secret-finder, the lens of God* has once again been delayed, this time from October to November.

The machine that will make sense of it all, or start an apocalyptic chain reaction in the matter of our planet, has a couple little helium leaks that need to be repaired. If I were the director of the project, I’d just get a couple interns to stick their fingers in the holes (or have them put their mouths over the leaks for hilarious squeaky interns), but the folks in Switzerland aren’t screwing around.

“We’re going to get it right this time! November? Maybe! Maybe later! Don’t push us, okay? Do you want us to blow up the world? We will, so help me, we will! I am so frustrated!” stated one scientist I just imagined.

So you’ve got one extra month, at least. What are you going to do with it? The possibilities are practically endless. Here are some suggestions:

  • Look at your muscles in a mirror
  • Oil your better muscles
  • See what sport fishing is all about
  • Go to Ikea and splurge. Buy all the wine racks
  • Arts and crafts
  • Watch True Lies with the sound off. Try to guess what the characters are thinking about
  • Google “Origami”
  • Pick one of your friends to be your enemy, but don’t tell them
  • Review your notes

BTW, if you’ve already forgotten what the LHC is, and what it’s supposed to do, check out some of our older posts on it here.

*When I enter Thunderdome, I want all of this to be my introduction. Especially “The Doomsday Atom-Smasher” part†

†Holla back, Mad Max enthusiasts! Who rules Bartertown?

Jul
21
2009

Middle Falls at Gooseberry Falls State Park: Three separate lava flows form the waterfalls.
Middle Falls at Gooseberry Falls State Park: Three separate lava flows form the waterfalls.Courtesy Mark Ryan
Recently my wife and I took a day trip to the North Shore of Lake Superior to hike around, take pictures, and see some great geology. Scenic Highway 61 follows the lakeshore all the way into Canada, and along the way several state parks present some of the most stunning scenery and spectacular geology you’ll find in Minnesota.

In Duluth, a brisk wind made the lake a bit choppy down around the harbor entrance and small white caps rolled into the beaches of Park Point, but along the North Shore the wind subsided and the lake was placid and sparkling. It was a beautiful day, with bright sun and cool to moderate temperature, and air that was an especially clear. Across the lake, Wisconsin stood out in bold silhouette on the south shore.

Our first stop was Gooseberry Falls State Park just north of Two Harbors. One of nine state parks along the North Shore, Gooseberry is located just beyond the tunnels that cut through massive diabase ridges known as Silver Cliff and Lafayette Bluff. Diabase is an intermediate volcanic rock that due to its cooling rate, contains coarser-grained crystals than faster cooling basalt and smaller crystals than slower cooling gabbro.

Columnar jointing at Gooseberry: Polygonal jointing is evident across the top flow of the Middle Falls. The joints formed during cooling of the basalt a billion years ago.
Columnar jointing at Gooseberry: Polygonal jointing is evident across the top flow of the Middle Falls. The joints formed during cooling of the basalt a billion years ago.Courtesy Mark Ryan
Gooseberry offers easy parking and paved walking trails to view the three main waterfalls (Upper, Middle, and Lower). Despite the brisk afternoon air temperature, the waters of the Gooseberry River were warm and kids were having no problem swimming or standing under the falls. Three tiers of lava flows give the falls their structure partially due to the columnar jointing that took place when the basalt was first cooling from the outside in and shrinking into hexagonal joint structures in the process. The columnar jointing is easily viewed atop the Middle Falls. Down river the upper most flow makes up the ledges along the lakeshore.

You might wonder why so much volcanic rock is found along the North Shore. The reason’s because 1.1 billion years ago, the North America continent began to split apart in what’s called the Midcontinent Rift System. From Michigan up through the middle of Lake Superior, down Minnesota and into Kansas, the continent began to separate, releasing massive amounts of flood basalts and explosive rhyolites across the region during several eruptions. The level of volcanism was incredible, lasting for several million years. In some places along the North Shore it’s estimated that the lava flows are piled up 18 miles thick! But for reasons unknown (and lucky for us) the continental division was aborted, leaving us with interesting geology, several rugged parks, and gorgeous scenery.

Palisade Head and Shovel Point: The extrusive igneous rock, rhyolite, formed these high cliffs. Both were created from the same lava flow but the area between them has been eroded away.
Palisade Head and Shovel Point: The extrusive igneous rock, rhyolite, formed these high cliffs. Both were created from the same lava flow but the area between them has been eroded away.Courtesy Mark Ryan
Our next stop was Palisade Head located within the boundaries of Tettegouche State Park. A steep road takes you to the parking area at the top of the promenade. There are a couple low walled overlooks built from local rock for viewing but you can also hike around if you want. The view is fantastic. Shovel Point, located in the park proper, can be seen sticking out over the lake to the northeast with the Sawtooth Mountains in the background. Both Palisade Head and Shovel Point were created from the same lava eruption, but one quite different from those that created Gooseberry. Whereas flood basalts created Gooseberry, an explosion of rhyolite formed Palisade Head and Shovel Point. Rhyolite is chemically similar to granite but rather than being an intrusive rock (one that cooled slowly underground) as granite is, rhyolite is extrusive, meaning it cooled relatively quickly on the surface. Evidence shows the lava flow that created both Shovel Point and Palisade Head was one of great explosive energy. As the mass of magma neared the surface pressure dropped and volatiles in its mixture (such as water) expanded its volume and punched it through a vent in the Earth’s crust in a hail of molten ash and rock. The molten material settled into a pancake-shaped mass that eventually cooled into a highly erosion-resistant rock. But the relatively rapid cooling from the outside in once again caused columnar jointing, like that seen in Gooseberry.

Face to face with North Shore geology: Palisade Head's sheer cliffs challenge local rock climbers.
Face to face with North Shore geology: Palisade Head's sheer cliffs challenge local rock climbers.Courtesy Mark Ryan
The jointing and high cliffs that reach up 300 feet above the lake make Palisade Head a favorite site for rock-climbing. A group was doing just that when we were there.

Cobble beach at Sugarloaf Cove: Glaciers deposited most of the loose beach stones. Wave action shaped and sorted them.
Cobble beach at Sugarloaf Cove: Glaciers deposited most of the loose beach stones. Wave action shaped and sorted them.Courtesy Mark Ryan
Our final stop was Sugarloaf Cove just outside the town of Schroeder. This preserve is a recent addition to the scenic North Shore. From 1943 to 1971, the cove was used by a paper company to ship rafts of pulpwood across the lake to paper mills in Ashland, Wisconsin. But today practically all traces of the business have disappeared and the 34-acre site is being preserved by the State of Minnesota and the Sugarloaf Interpretive Center Association for educational purposes. Seven acres have been designated as a State Scientific and Natural Area. A fenced area protects a native plant restoration project where volunteers planted over 12,000 native trees, plants, flowers, and grasses.

Rock sorting at Sugarloaf Cove: Lake Superior's wave action sorted beach deposits along Cobble Beach. They're all along a 50-yard stretch of the beach.
Rock sorting at Sugarloaf Cove: Lake Superior's wave action sorted beach deposits along Cobble Beach. They're all along a 50-yard stretch of the beach.Courtesy Mark Ryan
There’s a one-mile trail that takes you through a pine plantation and alder thicket and down along the lake’s rocky shoreline and to the cove. Across the cove is Sugarloaf Point, which used to be an island but is now connected to the mainland by a tombolo, a shoreline feature formed from wave action depositing sediment over a shallow area of the lakeshore. As you walk the beach toward Sugarloaf Point you’ll notice the beach deposits become increasingly larger in size, going from fine sand to large cobbles, and even an occasional boulder. Glaciers carried most of these stones from areas north and northeast, smoothing their edges in transport and depositing them here as glacial till. Lake Superior’s wave action continued rounding the stones, at the same time sorting out the sand, gravel, and cobbles by size.

Multiple lava flows at Sugarloaf Cove: Zeolites (close up in right photo) show the top of one basalt flow in contact with the bottom of another.
Multiple lava flows at Sugarloaf Cove: Zeolites (close up in right photo) show the top of one basalt flow in contact with the bottom of another.Courtesy Mark Ryan
On the south side of Sugarloaf Point several lava flows can be seen piled one atop the other. When lava poured out on the surface a billion years ago, gases within the molten mixture formed bubbles that rose to the top of the flow much like bubbles forming on top of a pancake. As the molten material cooled into rock, these gas pockets – known as vesicles – became trapped. Additional pulses of lava soon covered the old flow and eventually everything became buried under younger sediment. At some point, hot ground water percolated through the buried masses of basalt and deposited different minerals in the vesicles in the process. These mineral deposits are known as amygdules and often appear as lighter crystals (zeolites) or agates inside the basalt layers. So when you see these lighter crystals in a rock sequence at Sugarloaf you know you’re looking at the top of a lava flow.

Lichen and cinqfoil on Sugarloaf Point: Along with wave action, several species of lichen and other plants are constantly at work eroding the North Shore basalts. The Sawtooth Mountains can be seen in the distance.
Lichen and cinqfoil on Sugarloaf Point: Along with wave action, several species of lichen and other plants are constantly at work eroding the North Shore basalts. The Sawtooth Mountains can be seen in the distance.Courtesy Mark Ryan
Vegetation on the point is very fragile, and visitors are requested not to walk out on it. At the far end of the point several lichens are working hard breaking down the basalt, along with the constant wave action of Lake Superior.

After this trip I’m anxious to go back and visit the other state parks along the North Shore. The area has so much to offer in terms of nature and geology. You can learn more by checking out some of the links below. There’s also a great book by geologist John Green titled Geology on Display that’s all about the geology of the state parks along the North Shore. If you get a chance this summer to visit these or any of the other beauty spots along Superior’s North Shore, take it - you won’t be disappointed.

LINKS

Jay Cooke State Park
Split Rock Lighthouse State Park
Crosby Manitou State Park
Temperance River State Park
Cascade State Park
Judge C. R. Magney State Park
Grand Portage State Park
More about the geological history of northeastern Minnesota
Restoration of Native Plant Communities at Sugarloaf Cove

Jul
20
2009

Super Solar Ring: ...but remember, don't look directly at it or you WILL GO BLIND!!!
Super Solar Ring: ...but remember, don't look directly at it or you WILL GO BLIND!!!Courtesy Incredible India

Get ready, because one of Newton’s laws is about to be tested. A little thing called gravity is going into question during the total solar eclipse on July 22nd.

I’m sure most of you have heard of or know what a solar eclipse is. If not, here’s a refresher: “A solar eclipse occurs when the Moon lies between the Sun and Earth, casting its shadow on our planet. Depending on the location of the observer on the Earth’s surface, the observer may see a total solar eclipse, a partial solar eclipse or none at all. If the observer is lucky enough to be located in a position where the moon’s umbra contacts the Earth they will witness a total solar eclipse of the sun.”

Unfortunately for those of us in St. Paul, the only way for us to see the total solar eclipse would be to buy a one-way ticket to the eastern hemisphere. The path of the eclipse will start in eastern India and end about 2,000 miles south of Hawaii. During which it will be visible for nearly 6 minutes in China, and that’s where Newton steps in (not literally of course).

Researchers at the Chinese Academy of Sciences are about to test the controversial theory that gravity drops slightly during a total eclipse. Originally observed in 1954, the French physicist Maurice Allais noticed erratic behavior in a swinging pendulum when the eclipse passed over Paris. The shift in direction of the pendulum’s swing suggests a sudden change in gravitational pull. Though tests have occurred since, nothing has been conclusive.

The best chance to prove the gravity anomaly is this Wednesday during the longest eclipse duration of the 21st Century. This is why Chinese geophysicists are preparing six different sites with an array of highly sensitive instruments to take gravitational readings during the total eclipse. The head geophysicist Tang Keyun states, "If our equipment operates correctly, I believe we have a chance to say the anomaly is true beyond all doubt."

May
18
2009

Earth Messenger
Earth MessengerCourtesy NASA

NASA's Earth Observatory is celebrating its 10th anniversary this year and in that time is has given scientist and the general pubic a new view on the earth and how it is changing. The Earth Observatory site has satellite images of events on the earth ranging from storms and climate change to the growth of cities. The images are not only interesting to look at but they have helped scientist research the changing of seasons, snow caps, and cloud patterns in a whole new way. With growing popularity the images are also being sought out by other agencies, for example when the coast of Louisiana was hit by a hurricane the images were used to get a clearer picture of the flooding in the cities. Check out their archives, you will see awesome pictures and learn something new about the planet we live on.