March 12, 2014
The Earth Science class for educators at Michigan Tech has an online textbook on Michigan Geography & Geology that’s pretty cool. The chapter on the Ledges at Grand Ledge includes At the Edge of an Ancient Ocean that talks about the rocks that make up The Ledges and begins:
The rocks at Grand Ledge are significant for several reasons. Grand Ledge is an “oasis” of bedrock in an “ocean” of glacial drift that blankets the Lower Peninsula, providing geologists a window into the distant past. The diverse set of sedimentary rocks contains a wealth of information on the plants and animals that dominated the Pennsylvanian Period, about 320 to 290 million years ago. The characteristics of the rocks allowed geologists to reconstruct the changing environment that marked the demise of a great inland ocean. The rocks have been quarried and hold economic value. Lastly, Grand Ledge is scenic and enjoyed by hikers, paddlers, and climbers.
Nearly all students of Michigan geology make a pilgrimage to Grand Ledge at some point in their careers. Good exposures of sedimentary rocks are rare in the Lower Peninsula. Not only are the rocks well exposed but they offer an opportunity to test your skills in identifying a variety of sandstones, some shale and limestone, and even 2 coal. The rocks are exposed in a few abandon quarries and in exposures along the Grand River. To get a good look at the rocks you will need drive between exposure north and south of the river. But don’t be discouraged; the distances are short.
As always in geology, the best place to start is at the base of the stratigraphic section, the oldest rocks. The lower part of the section contains shale, siltstone, and type of sandstone called greywacke. The shale is gray and so fine-grained that you cannot see the mud-sized particles that compose it. If you are brave, you might put a tiny piece in your mouth and push it around a bit. Shale feels smooth, almost creamy, a result of the mud. The shale is also soft and erodes to relatively gentle slopes. Shale is exposed at the base of the layers at the Face Brick Quarry. Think of the light-colored siltstone as a silty shale. You might rub the rock against your thumb and see if any small, visible grains come loose. Again, a taste test might be in order. Siltstone will leave a 3 gritty feel in your mouth. Siltstone is exposed at the base of the rock layers at the American Vitrified Quarry. The greywacke is a greenish-gray colored sandstone and the sand grains are visible to your unaided eye, no tasting required. With a hand lens you can see the rock is made of a mixture of sand sizes, what geologists call poor sorting, and a variety of sand compositions, including quartz, feldspar, mica, and fragments of pre-existing rocks. Greywacke is exposed just above the beach at the Face Brick Quarry.
More winter wallpaper on Michigan in Pictures.
March 11, 2014
NOAA’s current space weather forecast reports an M Class (moderate) solar flare from solar region AR2002. Spaceweather.com adds that AR2002 has destabilized its magnetic field, making it more likely to erupt, and that NOAA forecasters are estimating a 60% chance of M-class flares and a 10% chance of X-class flares during the next 24 hours. X-class flares are major solar events that can spawn incredible auroras visible far to the south of us, planet-wide radio blackouts and long-lasting radiation storms. Click to Space Weather for a video of AR2002 development.
While there’s not much chance of a major event, I thought it was interesting that 25 years ago this week, one of the most significant solar storms in memory created a spectacle in the skies as it demonstrated the power and danger of solar weather to modern society. A Conflagration of Storms begins:
On Thursday, March 9, 1989 astronomers at the Kitt Peak Solar Observatory spotted a major solar flare in progress. Eight minutes later, the Earth’s outer atmosphere was struck by a wave of powerful ultraviolet and X-ray radiation. Then the next day, an even more powerful eruption launched a cloud of gas 36 times the size of the from Active Region 5395 nearly dead center on the Sun. The storm cloud rushed out from the Sun at a million miles an hour, and on the evening of Monday, March 13 it struck the Earth. Alaskan and Scandinavian observers were treated to a spectacular auroral display that night. Intense colors from the rare Great Aurora painted the skies around the world in vivid shapes that moved like legendary dragons. Ghostly celestial armies battled from sunset to midnight. Newspapers that reported this event considered the aurora, itself, to be the most newsworthy aspect of the storm. Seen as far south as Florida and Cuba, the vast majority of people in the Northern Hemisphere had never seen such a spectacle. Some even worried that a nuclear first-strike might be in progress.
…Millions marveled at the beautiful celestial spectacle, and solar physicists delighted in the new data it brought to them, but many more were not so happy about it.
Silently, the storm had impacted the magnetic field of the Earth and caused a powerful jet stream of current to flow 1000 miles above the ground. Like a drunken serpent, its coils gyrated and swooped downwards in latitude, deep into North America. As midnight came and went, invisible electromagnetic forces were staging their own pitched battle in a vast arena bounded by the sky above and the rocky subterranean reaches of the Earth. A river of charged particles and electrons in the ionosphere flowed from west to east, inducing powerful electrical currents in the ground that surged into many natural nooks and crannies. There, beneath the surface, natural rock resistance murdered them quietly in the night. Nature has its own effective defenses for these currents, but human technology was not so fortunate on this particular night. The currents eventually found harbor in the electrical systems of Great Britain, the United States and Canada.
You can read on for more about how the storm spawned a power outage in Quebec and pushed US systems to the brink of collapse. If you want to totally geek out on auroral science, check this article out about how the Earth’s magnetosphere actually extends itself to block solar storms.
February 15, 2014
You may have seen one or more of these incredible ice photos making the email round as Lake Michigan or Lake Huron ice. The Snopes.com article above says that they and many more were taken Antarctic base of Dumont D’Urville by Tony Travouillon in 2002. A shout-out to TC weatherman Joe Charlevoix who posted a story earlier in the week debunking the hoax!
While we don’t have that level of brilliant blue, our ice does get bluish. Via Shawn Malone at the Earth Science Picture of the Day, I found an informative article by Larry Gedney about blue ice & snow that says:
It is a common misconception that the blue color exhibited by glaciers, old sea ice, or even holes poked into a snow bank is due to the same phenomenon that makes the sky blue–light scattering. But nature has more than one recipe for producing the color blue. In frozen water and in the sky the processes are almost the reverse of each other.
A blue sky results when light bounces off molecules and small dust particles in the atmosphere. Because blue light scatters more than red does, the sky looks blue except in the direction of the sun (particularly when the sun is near the horizon and the blue light is scattered out of the sunlight, leaving the red color of sunrises and sunsets).
When light passes through ice, however, the red light is absorbed while the blue is transmitted. Were the operating process scattering as in the atmosphere, then the transmitted light would be red, not blue. However, because of the large size of snow grains and ice crystals, all wavelengths of visible light are scattered equally. Scattering therefore does not play an appreciable role in determining the color of the transmitted light.
It takes an appreciable thickness of pure ice to absorb enough red light so that only the blue is transmitted. You can see the effect in snow at fairly shallow depths because the light is bounced around repeatedly between ice grains, losing a little red at each bounce. You can even see a gradation of color within a hole poked in clean, deep snow. Near the opening, the transmitted light will be yellowish. As the depth increases, the corer will pass through yellowish-green, greenish-blue and finally vivid blue. If the hole is deep enough, the color and light disappear completely when all the light is absorbed.
The color of ice can be used to estimate its strength and even how long it has been frozen. Arctic Ocean ice is white during its first year because it is full of bubbles. Light will travel only a short distance before it is scattered by the bubbles and reflected back out. As a result, little absorption occurs, and the light leaves with the same color it had when it went in.
There’s more (lots more) on water, snow & ice from the University of Alaska, Fairbanks.
Heather took this photo at Point Betsie last weekend. View it bigger and see more in her Winter slideshow.
February 8, 2014
The other night I came across an incredible video tour of the International Space Station by Commander Sunita Williams of NASA before she departed for Earth. It’s one of the most amazing things I’ve ever seen and does so much to make the experience of living, working and moving in space a lot more tangible.
Commander Williams is a big part of what makes this video so engaging. She guides you through the corridors of the space station with a skill for explanation that I have seldom (if ever) seen. If she were born a hundred or so miles to the east, she’d be a Michigander. She wasn’t though, so I guess it might not be true what my grandmother told me about Ohio. Read her blog of the mission at NASA. (great photos)
Kudos to Commander Williams, and to everyone who worked across national and other divisions to make the ISS a reality. This video really made my day and I hope it makes yours – click to watch on YouTube!
About the photo, Kevin writes:
The International Space Station flies through the constellation Orion in the skies over downtown Grand Rapids, Michigan on a chilly and windy October evening.
This was a low pass in the southern sky (maximum altitude 34 degrees) so I decided to drive downtown to see if I could get a shot as the spacecraft flew over the buildings. I had done something similar in March of 2010, and figured if I could do it once, a second time wouldn’t be a problem.
Using timings and coordinates from Heavens Above via their Android app, I was able to determine where the flyover would begin and end. I set up my camera and did a few test shots before the actual time, and was ready by the time ISS was visible over the south-southwestern horizon.
I timed it so the light from the station would already be in the FOV of the lens, and opened the shutter until it disappeared a short time later. Then it was home to the computer to see if I could make anything out of the image. I guess I did.
Who says you can’t do astrophotography from the city? :)
More nighttime photos on Michigan in Pictures.
The Pictured Rocks National Lakeshore’s Geology Field Notes page has this barely comprehensible stuff to say about Miner’s Castle:
The Miners Castle Member is a soft, crumbly, quartz sandstone (with abundant garnet content) about 140 feet thick; its complete section is exposed in the Pictured Rocks Cliffs between Sand Point and Miners Castle. Sediments of this member are generally poorly sorted.
Capping the easily eroded Miners Castle Member of the Munising Formation in the western half of Pictured Rocks, is the resistant Early Ordovician (480-500 million years old) Au Train formation. The Au Train Formation is a light brown to white dolomitic sandstone that forms the resistant cap to the underlying softer sandstones. The numerous falls in Pictured Rocks National Lakeshore are the result of this caprock.
Read on for much more about the geology of Pictured Rocks. Erosion is indeed a factor with one of the most visible instances being April 13, 2006, when one of the pillars of Miner’s Castle collapsed.
December 17, 2013
110 years ago on December 17, 1903, Orville & Wilbur Wright made aviation history with four flights of the Wright Flyer.
Seeking Michigan has a feature by Roger Rosentreter from Michigan History Magazine titled First in Flight? It tells the story of Augustus Herring, who followed his dream in St. Joseph and became one of this country’s aviation pioneers perhaps even pre-dating the Wright Brothers in powered flight:
Herring worked with other aviation pioneers, especially in experimenting with gliders. Finally, he put a gasoline-powered engine on a two-winged glider that had a wingspan of nineteen feet. The 2.5-horsepower engine (smaller than most of today’s lawnmower engines) gave the “pilot” power for about fifteen seconds In October 1898, Herring “flew” this contraption on the Lake Michigan beach at St. Joseph, Michigan. On a second flight, according to one eyewitness, the airplane stayed in the air for ten seconds and went seventy-three feet.
Herring had problems. His airplane was difficult to control, and he needed a lighter-weight engine to keep the plane flying longer, but none existed. Finally, the photographer who had been on the beach that day failed to capture Herring’s plane in the air. There was no visual proof that he had flown.
…Historians have mixed reviews for Herring. One labeled his work as “insignificant,” while another said, “one cannot deny that Herring flew or was very close to having flown.” As for Augustus Herring, he never claimed to be the first to fly. He knew his engine-powered glider was not a practical airplane. But he argued that his work proved that powered flight was “solvable.” That claim is undisputed.
December 9, 2013
If there’s a front page of the internet, it’s probably Google. They manage to pack quite a lot into a spare layout. Today would have been computer science pioneer Grace Hopper’s 107th birthday, and in addition to a tribute doodle, Google is featuring a ridiculously star-packed video about An Hour of Code.
An Hour of Code is a project of Code.org, a non-profit dedicated to expanding participation in computer science education by making it available in more schools, and increasing participation by women and under-represented students of color. The state of Michigan has 13,484 open computing jobs (growing at 4.1x the state job growth average), 1,930 annual computer science graduates and just 78 schools teach computer science. You can get all the details on how you can help encourage schools to require more computer programming from code.org!
December 7, 2013
Waaaay back when I started out on the capital “I” Internet with an online publication called the Northern Michigan Journal. For over five years I edited NMJ, producing around 4 issues a year that featured some interesting work from a wide range of writers & artists.
Two of these were my friends Jerry Dennis and Glenn Wolff, a writer/artist duo who collaborated on several books. Their first was called It’s Raining Frogs & Fishes: Four Seasons of Natural Phenomena and Oddities of the Sky, a fascinating romp through the oddities and beauties of the natural world through Jerry’s captivating prose and Glenn’s engaging drawings. You can click that link to learn more about the book from Jerry’s website. Trust me, it’s the perfect gift for the nature lover or scientist in your life!
There is more to the birth of a snowflake than Aristotle’s assertion that “when a cloud freezes there is snow.” Snow is not merely frozen rain. Rain occasionally freezes, falling to the ground as sleet or freezing rain, but snow originates independent of atmospheric drops of water. Individual ice crystals for high in the atmosphere when water vapor freezes around dust or other particulates. Without particles to serve as condensation nuclei, water vapor can be cooled to -40 degrees Fahrenheit before freezing occurs. A supercooled cloud of this sort seeded with a few particles often escalates into a snowstorm. The individual crystals collect additional molecules of water vapor one at a time, building on one another symmetrically in a rapidly growing, widening circle. Temperature, wind, humidity, and even barometric pressure will determine the growth and ultimate form of the crystal. Large and elaborate crystals for at higher temperatures and humidity while, while the small, basic crystals such as those common in polar regions form when temperature and humidity are very low. As the crystals fall they bump against each other, breaking off pieces of ice that in turn serve as nuclei for new crystals. As they pass through warmer layers of air they adhere to one another, congregating into snowflakes that may contain a thousand or more crystals.
Snowflakes, then, are aggregates of snow crystals. When the temperature is near or slightly above freezing, snowflakes become wet, adhere to other flakes, and grow to two or three inches in diameter. On very rare occasions, they can grow larger yet. According to a report in a 1915 issue of Monthly Weather Review, a snowfall on January 28, 1887 dropped flakes “larger than milk pans,” measuring fifteen inches in diameter by eight inches thick across several square miles near Fort Keogh, Montana.
Only when the temperature remains consistently below freezing will complete, individual crystals fall to the ground. If the temperature of the cloud they form in and the air they descend through is warmer than 27 degrees Fahrenheit, the crystals tend to be flat and hexagonal. Between 27 and 23 degrees, they tend to be needle-shaped. Between 23 and 18 they are likely to be hollow and columnar, with prismatic sides. At temperatures below 18 they can be columnar, hexagonal, or fernlike. Virtually all have six sides. That hexagonal tendency is something of a mystery, although some scientists suggest it is produced by electrical charges in the crystals, while others say it is basic to the molecular structure of water molecules. The atoms in a molecule of H20 are arranged, in physicist Hans C. von Baeyer’s graphic description, “with two little hydrogens stuck onto a big oxygen like ears on a Mickey Mouse’s head.” Scientists like von Baeyer believe that the angle at which the hydrogen molecules protrude from the oxygen atom–about 120 degrees–causes snow crystals to grow to a six-pointed symmetry that repeats the molecular structure of water.
Read on for much more including whether or not two snow crystals are alike, heavy snowfalls and snow words & myths.
November 19, 2013
Two interesting auto-related tidbits came across my desk in the last couple of days.
The first is from Deadline Detroit, and shows an excerpt from a 1917 newsreel with a Detroit Police Department driver-safety campaign trying to persuade drivers to slow down.
Fast forward to today and beyond with Michigan Senate approval of self-driving vehicle testing on Michigan roads. The Detroit News reports that (pending House approval):
Under the Michigan rules, a driver would be required to be in the driver’s seat at all times during testing to take over in the case of emergency. Manufacturers and suppliers would use an “M” license plate for automated vehicle testing. “Upfitters” of automated vehicles, such as Google, would be permitted to test vehicles along with manufacturers.
The action comes as the U.S. Congress is set to hold a hearing Tuesday on autonomous vehicles amid growing interest among automakers. They will hear from General Motors Co. and Nissan Motor Co. executives along with the Michigan Department of Transportation.
…The University of Michigan says that by 2021, Ann Arbor could become the first U.S. city with a shared fleet of networked, driverless vehicles. That’s the goal of the Mobility Transformation Center, a cross-campus U-M initiative that also involves government and industry representatives. Ann Arbor has been home to a 15-month-long ongoing study of 3,000 vehicles that are linked to one another in a test of technology to see if connected cars can help each other avoid crashes.
More automotive features on Michigan in Pictures.
November 6, 2013
During a hike late this summer I noticed the oddly bent trees shown above in Sleeping Bear Dunes National Lakeshore, Michigan. It’s likely that snow loading or extreme icing from big storms during a previous winter caused this bowing. These trees were perhaps big enough to bend but not yet so inelastic as to break beneath heavy the snow/ice load. In subsequent years, with less damaging weather conditions, their crooked trunks may begin to straighten. Photo taken on September 21, 2013.
If you have photos of interesting natural phenomena, consider submitting them to the EPOD!