For a long time I’ve taught about the Kola Superdeep Borehole, the farthest humans have dug into the Earth’s crust. While getting 12,262 m deep, it never broke through to the mantle.
Now, scientists have gotten core samples from the mantle, without having to beat the Kola borehole. By digging along the Mid Atlantic Ridge, they were able to pull rocks from the upper mantle from a “tectonic window” where the mantle is very near the surface (of the Earth, not the ocean).
When humans migrated across the Bering Strait to N America during the last Ice Age, they brought along domesticated dogs. Soon after, black coats appeared in the native Gray Wolf population, caused by increased melanin due to changes in a single gene.
Known as the K gene (Japanese kurokami for ‘black hair’), the dark coat resulted from a variant introduced by interbreeding with dogs. Wolves carrying one or two copies of the KB version are black.
The frequency of black wolves increases from the Arctic to Mexico. Black coats are more common in regions with canine distemper outbreaks. It turns out that the K gene is a natural antibiotic (“defensin”) that confers immunity against distemper.
But the black coat variant also carries a fitness defect: few pups with 2 copies survive to adulthood. Gray-coated wolves produce larger litters and are more aggressive than black-coated wolves during territorial conflicts.
We studied Mono Lake in my 6th grade class. It’s an interesting ecosystem because the lake doesn’t have any streams taking water away from the lake — it’s a dead end. Over the millennia the lake has gotten very salty, to the point where fish can’t live in it. But there are 2 varieties of algae, and they form the base of a somewhat small food web.
Back in 1913 the city of Los Angeles decided they needed the freshwater that was flowing into Mono Lake and others and built the largest gravity fed aqueduct to bring the water to LA. A lawsuit brought by the Mono Lake Committee managed to save Mono Lake, but not nearby Owens Lake, which dried up entirely. The agreement stipulated that LA would get 1/4 of the water going to the lake, and Mono Lake got the rest.
For years I’ve been fascinated by the deepest humans have ever dug into the Earth. The Kola Superdeep Borehole in the Kola peninsula of Russia is over 12 km deep. It took 20 years to dig that far, and they had to stop because it was so hot down there (180 °C) that the rock was plastic and flowed, making drilling nearly impossible. The project was stopped in 1995.
But it looks like scientists may have found a way to dig deeper holes, and use the great heat down there to generate power. We’ve been using geothermal power for a long time, but it hasn’t been feasible to do in where the surface crust isn’t hot. The really interesting thing is the way we may be able to drill deep, down to where it’s 500 °C.
Quaise, a spinoff from MIT, has a way to use millimeter-wave beam technology to easily and quickly break even the hardest rocks. They claim to be able to complete a 20 km deep hole in just over 100 days.
If this works (and that’s still a big if), it could lead to reliable geothermal power, without requiring CO2 emissions after the hole is dug. They’re looking to have a 100 megawatt geothermal plant operating in 2026.
I’ve been learning about the History of Science courtesy of Crash Course. It’s really interesting.
I first found out that the history of science was fascinating from Connections by James Burke. This was a PBS series back in the day (the late 1970s) (and it’s not really PBS, since it came across the pond from the BBC), and each one traced a series of scientific and technological discoveries from ancient to modern times. The first episode traced the invention of the plough to modern power blackouts. While the show looks dated (hey, it’s over 40 years old!), if you can get past that, it really rewards viewing. You can watch it on YouTube here.
Well, I just finished it today. There’s a lot there to unpack. I think they did a really good job with it. I’m also watching their course on Outbreak Science, and I want to start watching Geography; I’ve always liked maps.