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Large crack in East African Rift is evidence of continent splitting in two
- mrfusion 9y agoWild eyed idea. Could we run a cable across this. Have it turn a gear. Then gear it up to a one million to one ratio and turn a giant generator with the motion? Free continental drift power?
- SteveNuts 9y agoSomething with that much gear ratio would essentially be locked. It would most likely just tear the mechanism apart before it did any actual work.
- agumonkey 9y agoThen a thousands of them over the split with a thousands less ratio :P
- deadmetheny 9y agoConsidering the drift is occurring at a rate of a couple millimetres a year...no.
- rplnt 9y agoWith high enough gearing that is plenty. The issue is we are not capable of building strong enough gears.
- IdiocyInAction 9y agoSeems like someone already had that idea, atleast for the continental shelf: https://patents.google.com/patent/US8258638 https://patents.google.com/patent/US8258638
- marshray 9y agoI love this idea, but the speed of separation is just a couple of cm per year. Unless the cable had absolutely no temperature expansion, weather changes would probably have a far greater effect on cable length than the imperceptible drift of the endpoints (which suggests another crazy idea interesting in its own right). One might build this deep underground to minimize temperature changes and provide the hard rock anchor points necessary for the forces involved.
- NegativeLatency 9y agoGo deep enough and you might as well just build a geothermal power plant.
- deadmetheny 9y agoWhich would have the side effect of actually generating power!
- theandrewbailey 9y agoKenya is way ahead of you: https://www.nytimes.com/2018/02/23/business/geothermal-energy-grows-in-kenya.html https://www.nytimes.com/2018/02/23/business/geothermal-energ...
- nojvek 9y agoKenya generates 47% of power from geothermal and 35% from hydro. For a third world country, it’s quite greener than most developed nations. https://mobile.nytimes.com/2018/02/23/business/geothermal-energy-grows-in-kenya.html https://mobile.nytimes.com/2018/02/23/business/geothermal-en... I do hope Kenya gets a electric car boom, because all of it’s fuel is imported. Solar + other methods could power the whole economy with relative ease. Being on equator means plenty of sun throughout the year.
- sannee 9y ago> weather changes would probably have a far greater effect on cable length than the imperceptible drift of the endpoints (which suggests another crazy idea interesting in its own right) There is a clock running for over a century based on a similar idea: https://en.wikipedia.org/wiki/Beverly_Clock https://en.wikipedia.org/wiki/Beverly_Clock
- jacquesm 9y agoYou'd stand a better chance to get that to work by using hydraulic pistons that are used to compress a working fluid using an appropriately placed lever.
- tzahola 9y agoLol! I hope this is not indicative of the level of physics education software engineers are exposed to nowadays.
- deadmetheny 9y agoConsidering my comment below was downvoted to -3, I don't have a lot of hope.
- krastanov 9y agoOr you both can consider stepping down from your high horses. It is a fun tongue-in-cheek idea, and the author explicitly mentioned the need for a gearbox. I am teaching physics and I will probably use this example in a lesson soon, because it is actually interesting to discuss why this idea would not work in practice (in principle all you need is indeed just a perfect gearbox).
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- marshray 9y agoPhysics taught me that all pulleys are frictionless. Mechanical Engineering may find some issues with it though...
- dang 9y agoPlease read https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html, which ask you not to snark or to post shallow dismissals. A good version of this comment would explain what's wrong with the original idea, so that readers who don't know could learn something.
- pvg 9y agoThere’s lots of other ‘free’ and ‘infinite’ energy around that is much easier to collect. You could go to the moon and make strawberry jam and then market it as ‘Space Jam’ but it’s simpler and cheaper to skip the whole moon part.
- _rpd 9y agoThis well known process, which will play out over tens of millions of years, appears to be receiving media attention because ... > A large crack, stretching several kilometres, made a sudden appearance recently in south-western Kenya. The tear, which continues to grow, caused part of the Nairobi-Narok highway to collapse and was accompanied by seismic activity in the area.
- pxndx 9y agoThat's literally the title of the article.
- _rpd 9y agoIf it hadn't gone through the highway, I doubt there would have been the flurry of "Africa splitting in two!" articles.
- TomK32 9y agoNo-one's allowing East-Africa its 15 million years of fame...
- Finnucane 9y agoI am imagining the copywriter fighting the urge to say "there's a rift in the Rift."
- mirimir 9y agoThere was a previous flurry of media attention about the extreme geology in Djibouti and Ethiopia. https://www.theguardian.com/world/2006/nov/02/travelnews.travel https://www.theguardian.com/world/2006/nov/02/travelnews.tra...
- FlimFlamManolo 9y agoShake Djibouti!
- xbryanx 9y agoLots of people don’t realize that North America almost did this same thing about a billion years ago. Check out the failed rift zone called the Midcontinent Rift. Ever curious why Lake Superior is shaped like that? MCR ground zero. https://en.m.wikipedia.org/wiki/Midcontinent_Rift_System https://en.m.wikipedia.org/wiki/Midcontinent_Rift_System
- delecti 9y agoWhat about how Lake Superior is shaped indicates anything weird is going on?
- lainga 9y agoDoes this also explain the extended butte-and-valley terrain in the Southwest?
- njarboe 9y agoThe butte-and-valley terrain, as you called it, is more from the uplift and slow erosion of a large area called the Colorado Plateau. The various sediments deposited on and off over a billion years or so have different erosion rates. When a thick, more weatherproof, sandstone overlies a more erodable shale you get those big cliffs and buttes. The area covered by Nevada, on the other hand, is being pulled apart over the whole state. This creates what is called a basin and range topography. The extension is mostly east-west and you can see the ranges and valleys mostly are north-south due to this. Lots of geothermal there as the spreading rock allows hot rock from below to move close to the surface.
- mirimir 9y agoI was also going to mention that. Also, it displays the same equiangular vertex of three rifts that we see with the Arabian, Nubian and Somalian plates. Which you also see in oxide scum on molten lead. Or on oatmeal, just before it's ready.
- anc84 9y agoNon-mobile link https://en.wikipedia.org/wiki/Midcontinent_Rift_System https://en.wikipedia.org/wiki/Midcontinent_Rift_System
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- vmarquet 9y agolemonde.fr published an article [1] yesterday, in which they debunk this news. A seismologist at Southampton University says [2] that it's unrelated to the rifting. [1] https://www.youtube.com/watch?v=4QJ8MmbAC_o https://www.youtube.com/watch?v=4QJ8MmbAC_o (in French) [2] https://twitter.com/seismo_steve/status/977258571716091904 https://twitter.com/seismo_steve/status/977258571716091904
- smoyer 9y ago"the South Atlantic ocean, which resulted from the break up of South America and Africa around 138m years ago – ever noticed how their coastlines match like pieces of the same puzzle?" No I had not but now that I look at it it's so obvious. And wow!
- blattimwind 9y agoAlfred Wegener noticed this about a hundred years ago and formulated that theory around this observation and some supporting evidence. However, until the 1950s and 1960s the why would they be moving? was wholly unanswered and Wegeners theories were not accepted until then.
- kzrdude 9y agoIt's remarkable how young that understanding is
- tboyd47 9y agoThey match, but only at a curvature slightly smaller than the Earth's curvature, spawning many theories about an expanding Earth in the early days of geology. Those theories have all now been debunked but they make for a fascinating read if you're into scientific rabbit holes.
- mirimir 9y agoAlso the North Atlantic, but less clearly. Also Greenland and northeastern Canada. And Greenland and Norway, I think.
- arethuza 9y agoOne related fact that I love is that the Congo and the Amazon used to be the same river - the Amazon reversing flow when the Andes rose up: https://en.wikipedia.org/wiki/List_of_rivers_by_age https://en.wikipedia.org/wiki/List_of_rivers_by_age
- phyller 9y agoDoes anyone else think this is just erosion in the soil due to heavy rain? That's probably too boring of a story though. I think an earthquake that pulled the land apart that wide would be a major news event.
- ams6110 9y agoSeems very plausible. Roads in my area are currently full of wide cracks and holes that appeared seemingly overnight, as happens every spring.
- hyperpallium 9y agoIf it's rift due to plate separation, wouldn't the crack go down all the way to the mantle? Not the 20-30 feet seen in the video.
- lisper 9y agoIt does, but in general when a rupture opens up at the surface, the side walls fail quickly and fill it in with loose material. It is only when a surface rupture is "fresh" that it looks as dramatic as this.
- hyperpallium 9y agoSure, the side walls fall in... but wouldn't that happen more easily near the surface, with loose topsoil, than for deeper rock? Meaning, that if the top part hadn't fallen in yet, the lower parts wouldn't have either. Perhaps pressure with depth is a factor, tending to press the sides together. Amd the deeper material might not be rock, but e.g. sand or other loose material.
- lisper 9y agoThere isn't just one well-defined crack. Where the plates are separating there is a whole zone of material that is being pulled apart and cracking open. The current crack is just one of many many fissures in the rift zone. And the individual fissures are jagged and ziggy-zaggy, so even if they had clean sidewalls you still couldn't see straight down to the bottom. Also, the crack is not filled in all the way to (near) the top. There are gaps and voids all the way down. The "bottom" that you see is just the first filled-in part. If you dug down you'd probably find more gaps. (I'm not 100% sure about this. I know about the mechanics of slip-strike faults because I live in California within walking distance of the San Andreas, but the African rift is different so I could be wrong about some of these details.)
- tomcooks 9y agoIt's not evidence of continent splitting but of soil erosion, much like what is happening in Rome[0] [0](http://www.lastampa.it/2018/02/14/italia/cronache/roma-si-apre-una-voragine-in-strada-e-alcune-auto-vengono-inghiottite-XpaU13uOgyKJewE0jOyThN/pagina.html http://www.lastampa.it/2018/02/14/italia/cronache/roma-si-ap...)
- edf13 9y agoProbably not... > and was accompanied by seismic activity in the area.
- rplnt 9y agoWas this a sudden shift of several feet on the ground level (because the underlying ground was in tension for years)? Or how does a crack that big form? Is it even as big as the hole? I.e. if we were to measure from two points across the crack - did they move as much as the crack is wide? Who would own the new land?