Published on YouTube Nov 25, 2013: FREE FACT: An oblate spheroid is a special case of an ellipsoid where two of the semi-principal axes are the same size.
2013CryosphereDeglaciationGlobalHydrosphereOceanographyRegionScience TalkSea Level HeightSea Level Rise

This is amazing and how these videos should be. Imagine a 10 second video
which only says “Seal level is measured by scientists calculating gravity
if the mountain is not there. this calculation is programmed into GPS
satellites”
THANK YOU FOR A NON 10 SECOND VIDEO!!!!
When we say Mt. Everest is 8850m tall, how do we know what sea level would
be beneath the mountain? NEW VIDEO!
I don’t think I’ve ever put that much thought into sea level before. My
mind is kind of blown by this.
I remember my father, a physicist, explaining this to me as a kid. He used
the geodetic model in his job, writing targeting programs for
intercontinental ballistic missiles.
What if there was an identical version of mount Everest, but made of
osmium. Since it would have more of a pull on the water wouldn’t that make
its sea-level higher, and therefor shorter even though its identical.
Waaay over my head.
Never knew that. Very awsem!
Wow! I never would have thought how much work has gone into this seemingly
intuitively simple concept – sea level!
Scientists of all kinds – the uncelebrated heroes of our civilization, just
doing their work.
Sea level is not the same everyplace?
Aren’t human beings such awesomely curious creatures?
Isn’t this more minuteearth content? Either way really cool video!
Isn’t this more minuteearth content? Either way really cool video!
Pesky continents moving around on the earth’s surface? Everything was
pretty awesome, up to that little error. Continents don’t move around. The
water does. Land masses spread apart as the earth is growing bigger and
bigger. But that’s another story. Otherwise, GREAT JOB! This is the best
explanation of the controversial sea level issue, on earth. Literally. This
makes history.
I did not realize that it was so complicated, i never thought it would take
a bunch if brilliant people to figure it out
The only thing that stuck was that Gravity was stronger or weaker at
different points on the earth. Quick tell me where gravity is weakest so
that I can take my wife there have her step on a scale and tell her, “See
honey, you’re not fat!!!”
I don’t think I’ve ever put that much thought into sea level before. My
mind is kind of blown by this.
Great visual explanation of Sea Level (in case you didn’t already know).
There is so much I don’t know that I wish I did. Thanks for making it one
thing less.
Awesome video. Just one question: shouldn’t this be on the MinuteEarth
channel?
Longer video=great! Thanks!
my mind is blown…..
I did not understand your free fact. -_-
Funny how all these new media creations promote the old media they are
supported by. Is there anyone under 20 still reading? You know, paper (or
in this case: vocals) containing information that requires attention spans
way over a minute, without providing visual input.
(I’m old(er), so I’m allowed to be a slow fart!)
Great visual explanation of Sea Level (in case you didn’t already know).
Defining what the sea level is might not be as simple as you think. This
three-minute video is most educational. Skip a few kitten pics today and
learn some geodesy instead.