Why Do Rivers Have Deltas?
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- čas přidán 15. 12. 2015
- Where rivers meet the ocean, coastlines tend to bend either inward or outward, creating estuaries and deltas. But how do they get those shapes?
A huge thank-you to the following organizations, all working toward sustainable deltas, for sponsoring this video: the Belmont Forum, the Sustainable Deltas Initiative, the National Center for Earth-Surface Dynamics, the St Anthony Falls Laboratory of the University of Minnesota, and the DELTAS project. These organizations study deltas around the world, in particular how they’re threatened by human activities such as building dams, channelizing rivers, and climate change-induced sea-level rise. If we don’t pay attention, we might lose the landform that allowed us to become civilized in the first place.
Thanks also to our Patreon patrons:
- Today I Found Out
- Jeff Straathof
- Mark Roth
- Maarten Bremer
- Tony Fadell
- Antoine Coeur
- Nicholas Buckendorf
- Alberto Bortoni
- Valentin
- Muhammad Shifaz
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Want to learn more about the topic in this week’s video? Here are some keywords/phrases to get your googling started:
- delta: the piled-up sediment (typically triangular, or greek-letter-delta-shaped) deposited by a river as it flows into a larger body of water
- estuary: a partially enclosed body of brackish (part salt, part fresh) water that connects one or more ocean-bound streams/rivers to the open sea. Geologists classify estuaries into four basic types (bar-built, coastal plain/drowned river, tectonic, and fjord), based on the geologic processes that formed them.
- ice age: this is a term that geologists use a little differently than non-scientists. Geologically speaking, an ice age is a fairly long period (~100-300 million years) of relatively cold temperatures on Earth. Within these long periods of time, the climate warms and cools lots of times, causing the ice sheets to retreat and advance; geologists refer to the colder time intervals as "glacials" and the warmer periods as "interglacials". We are currently in an "interglacial" phase (that started ~15,000 years ago) of an ice age that started ~2.6 million years ago, but because that's kind of complicated, we just say "the end of the last ice age" when what we really mean is "the end of the last 'glacial' cycle of the current ice age."
- marine transgression / marine regression: on the surface, these are just fancy ways of talking about sea level going up and down. But for geologists, "transgression" and "regression" are more useful, because land sometimes goes up and down too. For example, if movement along a tectonic fault causes part of the coast to drop below sea level, it might get flooded, but it wouldn't be accurate to attribute the flooding to sea level rise. So geologists describe the situation as "marine transgression" instead. These terms comes in handy when we're talking about deltas and estuaries: deltas are formed by marine regression, and estuaries by marine transgression.
___________________________________________
Credits (and Twitter handles):
Script Writer: Emily Elert (@eelert)
Script Editor: Kate Yoshida (@KateYoshida)
Video Illustrator: Omkar Bhagat (@TheCuriousEnggr)
Video Director: Emily Elert (@eelert)
With Contributions From: Alex Reich (@alexhreich), Henry Reich (@minutephysics) and Ever Salazar (@eversalazar)
Music by: Nathaniel Schroeder: / drschroeder
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References:
Bhattacharya, J.P. (2003) Deltas and Estuaries, In: Middleton G.V. (editor) Encyclopedia of Sedimentology, Kluwer Academic 145-152. www.geosc.uh.edu/docs/geos/fac...
Day, J., Gunn, J., Folan, W., Yáñez-Arancibia, A., & Horton, B. (2007). Emergence of complex societies after sea level stabilized. Eos Trans. AGU Eos, Transactions American Geophysical Union, 88(15), 169-170.
Giosan, L., Goodbred, S.L. (2006) Deltaic Environments. Encyclopedia of Quaternary Science. www.whoi.edu/science/GG/coast...
Gupta, A. (2007). Large rivers: Geomorphology and management. Chichester, England: John Wiley.
Russell, R.J. (1967) Aspects of Coastal Morphology. Geografiska Annaler. Series A, Physical Geography 49: 299-309. (Abstract) www.jstor.org/stable/520896?se...
Wright, L.D. (1977) Sediment transport and deposition at river mouths: A synthesis. Geological Society of America Bulletin 88:857-868. - Věda a technologie
Rivers are like belly buttons...said no one ever besides minute earth. very creative
make sense, since the cord is like a bloody river
@@ffccardoso *where's the plug? I'm definitely not cutting your internet.*
So why does the Congo River have no delta despite emptying into the ocean?
@@koharumi1 The St. Lawrence river in Canada doesn’t really have a delta either, and yet it empties into the ocean.
the real question is why do adam and eve have belly buttons in all their paintings
Lmao got me weak
Because they were made to be like or look like any other human in the future? I don't believe in Good though.
Maybe religion is made up and many believed in it?
@Farm of Potatoes That's one of the many problems humanity has going on...
Harsh Dhakad yeah but they weren’t birthed out by a woman they were put on earth by god (well if you believe in god that is)
"Sir, the ground is frozen sir, the sea is getting back at us"
"NONSENSE!!! Get the sendiments, pile them all up and see who'll be laughing now!!"
That's how we Dutch think.
Lol
So far the sea is winning. Cuz 71% water
Lol there is land in the bed of oceans land won by 100%
The land might learn to melt earth so hard the water melts.
Good ol' MinuteEarth. Answering questions that I didn't even know I had.
+Deadeyes Yeah, thats my favourite type of questions :)
+Deadeyes xD
Lol
Damn still live huh
Godsake please never show belly buttons in a video ever again
Eileen Blurrr same
same!
Just mentioning then cause suffering for me!
Bellyist
@Yernazar Seitmaganbet >_
*triggered*
Okay, but now answer why people have innies and outies.
I was thinking the same thing. Outies ftw!!!!!
+No Bueno When the umbilical cord falls out, sometimes it pulls the skin, and sometimes it doesn't. That's quite simple.
Daviji Weirdo but why are there innies as opposed to bellybutton-less people.
Belly buttons are scars from your umbilical cord. Where the midwife puts the peg to close the cord determines whether you develop an innie or outie. If the peg is further away, you get an outie, if it's closer, you get an innie. Some people don't have belly buttons because the doctor had to sew the umbilical chord shut.
How the umbilical cord is cut.
This was a surprisingly easy explanation! Great work!
OUTIE BELLY BUTTONS ARE SO FUCKING WEIRD
yes !
what did the dinosaurs know about hillary clinton -why would you say that ._.
SHUT UP
Ikr
I have a kink for them, but yes.
There are three kinds of people on earth: the people that can count, and those who can't.
There are 2 types of people:
Grammar Nazis
Neo-Nazis
Hitler
+Zonneschijn where did the third type go!
el sam I think that I'm the second type of people and you're the first :D
Zonneschijn LOL
+Zonneschijn
r u grammar nazi, neo nazi or hitler?
I was taught at school, that river deltas form where is a little variation between high and low tide, so the sediment doesn't get washed off. You can notice that most rivers that flow into open ocean have wide estuaries, and those which flow to closed seas (i.e. Caspian, Mediterranean), tend to have branchy deltas. Exception would be Ganges - Brahmaputra, which has huge delta, but empties basically into open ocean.
Δ's?
+Dark Rush Yes, Δ's
You on a Mac?
+Shvet Maharaj No, I'm on my HTC A9. If you're wondering how I made the Δ, I used a Greek keyboard you can download from the Play Store or change in your keyboard settings.
Or maybe δ's?
+Dark Rush Ναι , Δέλτα -.- It's pronounsed Thelta not Delta.
when a 2 minute video teaches you more than a 2 hour class
lmao
I feel like videos like these, and learning these kinds of things are important, even though the specific information it will most likely not be important to anyone watching unless they're a geologist, I think this kind of opening your mind and looking at things is important for people to watch because while the information about rivers cannot be applied to other areas of life, I think the understanding of logic from watching this does.
its fun to know how things are formed and work instead of wondering how and why. I love looking at nature and understanding how it was formed its like looking back at time ,its amazing how ones imagination can visualise what happened in the past with a little understanding
Because Epsilons are too expensive...
+TheyCallMeGawd Only for non-continuous functions. With continuous functions for every epsilon you get a delta; it's like two for one!
Because delta was lonely and all the other Greek letters were taken
+istari314 Ha!
+William White Ϟ is still waiting...
Eh, it's all Greek to me.
Thank you, for another wonderful, and amazing video!
I... I didn't know outies existed...
+Melanie Trotochaud lol
+Melanie Trotochaud same here
Me too :D
My grandpa has an outie
Melanie Trotochaud I have an inny
Nice explanation of a tide dominated delta! You could go beyond and explain about types of estuaries and other deltas. Thank you!
The river is the umbilical cord
Good job guys! Learned a lot, so I left a like 🤗
Thank you! This explanation helped a lot!
"The fertile rivers that have helped foster human civilisation"
Indus: "Am I a joke to you?"
Yes
Indus was a pretty helpful in the beginning of human civilization
What a fascinating explanation to a question I never realized I wanted answered. Thanks man, love this shit.
This is helping me with my studies! Thanks a lot!
This is a really good explanation of what a delta is and I love your voice!
Literally the only thing I remember about this video: “rivers are like belly buttons”
#TeamInnies!!!
+Maester Marwyn Your labelled political compass is super dumb fyi
And so are you my friend.
Maester Marwyn I wasn't trying to be mean, you probably didn't even take time to look at it. Here's a thread explaining why if you're interested: www.reddit.com/r/badpolitics/comments/3p09cl/labelling_the_political_compass/
Thank you, I thought you were merely trolling me at first. Sorry if i was a bit snappy.
BOO NO
That video was quick and informative. Thank you
Thanks for uploading this.
*Clicks on video to learn geography*
"The world is divided into two kinds of people: Those with innie belly buttons and those with outtie belly buttons"
*Clicks away*
Neonexus jf
Fd
Neonexus m
What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps, has a bank but never loans, has an innies and outies but got no belly button?
A river!
Feather
#CaptainObvious
River
The answer is obviously a river.
I dont know tell me
A terrific episode. Bravo!
What a beautiful video. Thank you
0:07 Thats not a belly button.
+Thomi Your profile picture makes that comment even better.
+Alchaeus hahaha xD
+Thomi a belly button always recognizes its kin
Thomi,yes it is
Κώστας Καραπαπαχατζηδιμιτρακόπουλος, yes
Outies are gross
+Dan Chen How intelligent.
+Dan Chen not just talking about belly buttons i suppose
I rather have an innie, but I'm scared of my belly button bc when I was little I watched an episode of ren and stimpy and stimpy and it was horrifying o_O rather have an outie
I have innie
+RooFooChoo um.. that show is demented...
An answer to a question I never really thought about... Thank you!
Great work,love it 🌸
0:26 to 0:42. It's a fight between Groudon and Kyogre. EYYYY WHERE MY POKEFANS AT?!?!?
LOL
Aldrick Espinosa me
Present 👍 Actually just finished Omega Ruby today
Bork(Here)
There are 2 types of people in this world - Those who understand math
+NightFury There are two types of people in this world: those who can extrapolate from incomplete information.
Explanation?
+NightFury there are only two types of people in this world. those who make arbitrary categories and those who do not.
*****
Good for you, now someone explain the joke? Has it to do with "Those who understand math" being x and the square root (if its positive) has two answers? Therefore two different types of people in "Those who understand math".
+NightFury there are two people in this world. me and the other guy who lives next to the high way.
i'm blown away. hats off
Simple enough to understand but enough to remember good job!
pretty good explanation but a thing or two is incorrect. Source: masters in sedimentology and stratigraphy
+Jackson Clarkson Please elaborate!
+Jackson Clarkson Also would love more detail!
+Jackson Clarkson I'm interested in hearing what input you have on this.
+Fuckgoogleplus That would be a nice troll
+Fuckgoogleplus I think Allah Created Rivers
I just had my geography exam today and a question was on delta. How I wish you could have released this earlier
i am having mine tomorrow
What would've you wrote, belly buttons?
im have mine tomorrow
@@malnutritionboy same
@@lisaplays5145 4 years later hahaha
best kind of illustration I've ever seen
Weirdly enough, I’ve never seen this channel, yet when I saw this it was already liked
Innies 4 lyfe
+SimplyMyAccount I've seen a lot of outies in my days, but they have all transformed into innies as they grew up.
+Isaxus Outies forever!!!
Terminal innie.
If the dirt in the water slows down as it reaches the end of the river, and thereafter stacks up and builds new parts of lands, then now, the rivers length is increased, the river, at the spot where new land has been "built" has re gained its flowing speed, and thus, the walls of the newly built land should be scraped off by the high speed water. But this doesn't happen, why?
Also, why does melting ice's water flow in a zigzag shape and not in form of straight lines?
I wonder why "rivers cut deeper and deeper valley's to reach the sea" - 0:52
I mean they were reaching the sea anyway. It would have been like a waterfall at the end. In case you want to know why rivers curve, this might help - czcams.com/video/8a3r-cG8Wic/video.html
@@AdityaPrasad007 My question as well. I suspect the answer is complicated, so the video just glossed over it.
@@AdityaPrasad007 waterfalls constantly erode the walls they are on, just like how rivers erode the banks on the side.
very nicely explained and commendable Animation..! Thanks Team- Minute Earth
Love the analogy in explaining what a delta is.
You forgot to put a dot on the world map for the Danube Delta...
+antoniu8
They also forgot the Rhine-Meuse-Scheldt delta (1 big delta & 3 rivers)
Aka The Netherlands and northern Belgium
And the Lena Delta, the largest delta in the world.
Liked the video just to make the count = 1,234 :D
+James Clark You're a hero :D
wow that's amazing! never knew this.
superb explanations!
How does a river flow during an ice age?
+Guillermo L. Ortiz Toledano Magic
+Guillermo L. Ortiz Toledano
Downhill?
Most ice ages aren't total, so those more equatorial rivers will keep flowing. Also as the ice recedes, some rivers will be freed and start flowing while the sea level is still lower due to the ice at the poles.
+Guillermo L. Ortiz Toledano
Science Magic!
#TeamInnies
Woo. St. Anthony Falls!!! Fantastic place and they are doing great work
Sick! Rivers is a topic I'm studying for AS Geography so this will be useful. Thanks!
Somehow talking about belly buttons feels gross and creepy and wrong.
was here to learn about delta formation. left with question about bellly buttons that i never thought i would.
Quick and useful explanation
That is a cute, simple, short and entertaining explanation!
mind blown, love it!
thank you! very helpfull
Wonderful video!
That explains the amazing coastline of Norway :)
i dont get how people dislike videos like this...i mean cmon he explains it so well...
Thank You 💕
Good vid helped with test revision
Very helpful
Well they have really good explanation 🙂
brilliant video!
This is the best explanation
I think I’m addicted to this channel
Great explanation 👍👍👍👍👍
1:01 I recognised the Exe estuary instantly, it's my natural habitat! I miss the salty tang of the mud on the air and the smell of seaweed gently decomposing in the afternoon sun, the call of the curlews and the clink of the rigging on sailboats.
this was funny and informative, thanks, my exam of geography is today!
What i didn't understand in school, i did now.... Thank you ❤️
Best explanation ever
Now i can get A+ on geography. Thanks for ur help
I can honestly say that I learned something today.
good explaining i like it
Superb bro
you are really good at drawing dude, of you drew this of course.
well explained.
Great video! Now to search your channel for content about sounds (geography). If it doesn't exist then I'd love it if you made one. I'm trying to understand why the coast of the USA has so many landforms and rivers running parallel to the coast. It's like aliens came down to solve the Coastline Paradox.
♥helped sooo much! thanks.♥
Very interesting!!!!
u guys got a new subscriber
Oh, now I get it. Thank you minute earth
So , what determines if the river delta will be "innie" or "outie"? The flow conditions that allow sedimentation?
I just finished learning about the Danube Delta for the semestrial paper
I probably won't be looking at rivers the same way ever again ! :o
Thank you so much for this treatment; because my first thought, on seeing the title was: not all rivers have deltas, so why is that? Much appreciated. Though the answer is through null information. Some rivers don't have deltas because the sediment load is washed away by the sea, would be my guess.
Thanks for picking Hilton Head Island on your map.. 1:04 I live there ^^
Wow the timing with the rise of civilization is really interesting. Sounds like "Guns, Germs, and Steel" could use an addendum.
Good overall explanation, now try the Sacramento/San Joaquin River delta :)
please upload more snd more videos
i learned more from this weird video than i did in my 80 min lecture of the geology class last week
This is helpful to all students
Thank you..
My teacher showed me this in school and told me to watch this for homework