The summer solstice arrives at 12:24 AM tomorrow when sun’s zenith is at its furthest point from the equator, making today the longest day of 2017. Vox’s article on the summer solstice has some interesting info about the solstice including a look at whether or not today is the longest day in Earth’s history:
Ever since the Earth has had liquid oceans and a moon, its rotation has been gradually slowing over time due to tidal friction. That means — over very, very long periods of time — the days have been getting steadily longer. About 4.5 billion years ago, it took the Earth just six hours to complete one rotation. About 350 million years ago, it took 23 hours. Today, of course, it takes about 24 hours. And the days will gradually get longer still.
Given that, you’d think 2017 would be the longest day in all of history. But while it’s certainly up there, it doesn’t quite take top honors.
That’s because tidal friction isn’t the only thing affecting Earth’s rotation — there are a few countervailing factors. The melting of glacial ice, which has been occurring since the end of the last ice age 12,000 years ago (and is now ramping up because of global warming), is actually speeding up Earth’s rotation very slightly, shortening the days by a few fractions of a millisecond. Likewise, geologic activity in the planet’s core, earthquakes, ocean currents, and seasonal wind changes can also speed up or slow down Earth’s rotation.
When you put all these factors together, scientists have estimated that the longest day in Earth’s history (so far) likely occurred back in 1912. That year’s summer solstice was the longest period of daylight the Northern Hemisphere has ever seen (and, conversely, the 1912 winter solstice was the longest night we’ve ever seen).
Eventually, the effects of tidal friction should overcome all those other factors, and Earth’s days will get longer and longer as its rotation keeps slowing (forcing timekeepers to add leap seconds to the calendar periodically). Which means that in the future, there will be plenty of summer solstices that set new records as the “longest day in Earth’s history.”
Frank took this shot on Wednesday from the Avalanche Mountain Scenic Overlook in Boyne City. As you can see, this will be the weekend for fall color across much of Michigan, so check out some great fall scenes on Michigan in Pictures and make your plans for a getaway!
The Detroit Free Press reports that the salmon population is plummeting in Lake Michigan. The article begins:
They are the king of the Great Lakes sport fish, luring thousands of anglers to Michigan waters every year for a chance to try to land them — and helping fuel a multibillion-dollar fishing and boating tourism industry.
But the Chinook salmon’s numbers are plummeting in Lake Michigan due to a combination of natural forces, unnatural invasive species, and the state Department of Natural Resources’ own efforts to dial back the population and prevent a more permanent population crash as happened in Lake Huron about a decade ago.
The salmon population on Lake Michigan is down 75% from its 2012 peak, said Randy Claramunt, a DNR Great Lakes fishery biologist based in Charlevoix.
A leading cause is a reduction in alewives, a silvery fish up to 10 inches long that is the salmon’s primary prey on the Great Lakes. The alewife population has been decimated by invasive zebra and quagga mussels that have changed the nutrient dynamics of the lakes.
Read on for more at the Freep.
Liz says that these decaying pilings in Lake Charlevoix at Boyne City are the only remnants of the docks and roundhouse that stood at the waterfront during the town’s lumbering days. About this photo she writes:
Haven’t played with these guys in a while. This is the best time of year for them: we start having more colorful sunsets, and the ice that remains out on the lake helps keep the water still closer to shore. These pilings actually launched my ice fixation years ago when I noticed the elaborate frozen coats they grow in the winter. And then they became a year-round obsession themselves.
By the way, there’s no monkey-business here other than darkening the pilings a little to make them solid black. This is how it looked.
More from Liz on Michigan in Pictures.
7 years ago I shared the story of the Southdown Challenger on Michigan in Pictures. I was happy to see that the oldest operational freighter on the Great Lakes is still in action. The feature on the St. Marys Challenger on Boatnerd.com begins:
Currently holding the honors of being the oldest lake boat still trading on the Great Lakes, the self unloading cement carrier St. Marys Challenger was built as a traditional Great Lakes bulk carrier as hull #17 by Great Lakes Engineering Works, Ecorse (Detroit), MI in 1906. This veteran of the lakes was launched February 7, 1906 as the William P. Snyder for Shenango Steamship & Transportation Co. (subsidiary of Shenango Furnace Co.), Cleveland, OH. Retaining her original overall dimensions, the St. Marys Challenger is now powered by a Skinner Marine Unaflow 4 cylinder reciprocating steam engine burning heavy fuel oil rated at 3,500 i.h.p. (2,611 kW) with 2 water tube boilers. The power is fed to a single fixed pitch propeller and the vessel is equipped with a bow thruster. The vessel is capable of carrying 10,250 tons (10,415 mt) in 8 holds at mid summer draft of 21’09” (6.63m). Cargoes of bulk or powdered cement can be unloaded by a fully automated system including air slides, conveyor equipment and bucket elevators feeding a forward mounted 48’ (14.63m) discharge boom.
Of note, the St. Marys Challenger is one of only two remaining U.S. flagged vessels still active on the Great Lakes to be powered by the classic Skinner Marine Unaflow steam engine. The other vessel is the car ferry Badger (2) which is powered by two of these engines and, in turn, remains as the only coal fired vessel still in active service on the Great Lakes. The only remaining Canadian-flagged steamer powered by a Canadian-built (Vickers) Skinner Unaflow engine is the James Norris.
Many more Michigan ships & boats on Michigan in Pictures!
Wikipedia entry for Charlevoix (pronounced shar-le-voy) says:
The city is situated between Lake Michigan and the western end of Lake Charlevoix, which drains into Lake Michigan through the short Round Lake/Pine River complex in the heart of downtown Charlevoix. Charlevoix’s Round Lake has been called the best natural harbor on Lake Michigan.
Charlevoix is named after Pierre François Xavier de Charlevoix, a French explorer who travelled the Great Lakes and was said to have stayed the night on Fisherman’s Island one night during a harsh storm. It was during this time that Native Americans were thought to have lived in the Pine River valley.
The City of Charlevoix website adds that Charlevoix first became a village in 1871 and was later established as a city in 1905. The city has a year round population of roughly 3,000 people. FYI, Round Lake is the little lake right off Lake Michigan whick opens into the much larger Lake Charlevoix – here’s a map of Charlevoix!