2019 The Poles - Arctic and Antarctic - News, Adventures, Expeditions
It looks like Dr. Michelle LaRue is back in Antarctica…counting Emperor penguins
This sounds like they will not require crowdsourcing for the count:
LaRue and her team have been developing an algorithm that can look at a satellite photo of a penguin colony and count all of the penguins in it.
And I’m more than happy not to have to count them…if the Weddell campaign is anything to go by
I guess we did work ourselves out of a job when we did the polygram campaigns. I wonder if they’ll be able to count penguins too.
Want to count penguins then?
Only if there was much closer magification Jim, I certainly wouldn’t consider counting the ones we saw during the Seal campaign
I agree. We could pick them out because of the staining on the snow, the colony, but not individual penguins. At least not for my eyes. We would need much better magnification than the previous campaigns. Hopefully that is what they are working on before launching the campaign.
They could always make the tags real tiny. Then you’d be able to tag individual penguins without covering those not tagged. Where’s there’s a will, there’s a way.
New NASA maps show that a group of glaciers spanning one-eighth of East Antarctica’s coast have begun to lose ice over the past decade, hinting at widespread changes in the ocean.
The first one is a repost from above…
I wonder if they will move Casey Research Station as it is so close to Totten Glacier?
Oops! Didn’t know. I was looking at an email from sealevel.nasa.gov, read both articles and posted them.
Edit: It was in the wee hours of the morning anyway.
Can I go slightly off topic here and ask a couple of “daft laddie” (= “stupid boy”!) questions that I’ve been trying to get an answer to for some time?
The polar ice caps are melting. This is releasing water from near the poles into the oceans. Much of the oceans are nearer to the equator. How will this movement of mass towards the equator affect the spin of the earth?
Taking the answer to that question into account, how will the increased amount of water in the oceans affect the tides?
(Note: This was my understanding about this after reading an extensive article on this subject. (I’ll see if I can hunt this up for you.)
First off, the magnetic fields are not perfect around the earth. There are many variances to them. Additionally, gravitational forces are not equal all around the earth. Areas with more mass (i.e.: land, ice sheets/glaciers, underwater mountain ranges, etc.) have a stronger pull than areas of less mass. Thus the earth has a wobble as it spins. Now to the water. Scientists have discovered that when the ocean rises in one area (say in the North Atlantic), it’s like water in a bath tub. It can “slosh around” back and forth from coast to coast (North America to Western Europe & NW Africa). Even with the rise in sea level here, there isn’t necessarily a rise of the same amount in the Pacific. There are many things that affect the way the water of the oceans are distributed. As to the water mass nearer the equator, the moon exerts it’s gravitational pull on the water which causes a “bulge.” The bulge is always moving as the moon orbits the earth, thus the tidal effect. The tides, the difference of land distribution (mass), and underwater mountain ranges all affect the earth’s wobble… and therefore its rotation. Little by little the earth is slowing down, but on such a grand time scale that we wouldn’t have noticed it if not for the atomic clock and precise measurements. Don’t forget that the moon also affects the rotation of the earth by the fact that its orbit is not in a perfect circle. The closer the moon is to the earth, the stronger the pull and the farther away its orbit takes it from the earth the less pull. This “give and take” action is an added factor to the wobble and rotation. Here’s another factor to consider. Since the earth’s axis is tilted as it orbits the sun, the sun’s gravitational pull is not always the same everywhere and every season. In summer in the southern hemisphere it’s got more of a pull, but in summer in the northern hemisphere it’s now pulling more up there. So the world’s oceans are in a constant state of sloshing back and forth, and up and down planet - so to speak.
As to an increase of sea level affecting the tides, the higher the seas, the more water is pushed farther back into the rivers and lowlands. The speed of tidal flows could also increase - in both directions. Rivers with low banks will overflow and increased flooding will occur. Rivers with high banks that confide the water will mostly see increases in the speed of the water as well as higher levels. Low tides may not be as low as they are now as in decades or centuries before. The difference in added weight between high and low also increases/decreases mass… which ever so slightly affects the earth’s gravity.
Confusing yet? There are so many different factors affecting our earth is challenging to tie them all together. One thing affects another, and in turn affects another, which in turn affects the first. I suppose you could call it the planetary mechanical system.
I’ll see about that article and will update this post when I do.
Many thanks, @Jim7. I’d appreciate the link if you manage to find it.
I understand what you are saying in the first part of your post but, simplifying things somewhat, the earth’s magnetism and axis and the sun and moon are pretty constant. The one significant change in the system that seems to be happening is the amount of liquid water in the oceans and we’re warned - globally - to expect higher sea levels. Even if these rises are not completely uniform, there must be a change in the mass distribution. I’d expect this, roughly, to be away from the poles and towards the equator. I’d also expect it to be greater in the southern hemisphere, where there is more ocean. If mass is re-distributed around a spinning object - in this case the earth - I’d expect measurable changes in its spin and, if the re-distribution is uneven, in its wobble. Has any work been done to predict these effects?
As a sailor, I tend to be less concerned about how far up a beach or river a tide will come than about the tidal flows off-shore. Will our current (excuse the pun) 28 day cycle of roughly 6 hours’ of ebb followed by 6 hours of flood change as sea levels change? As a secondary point, will the tidal range (the difference between successive low and high water levels) change or will we see the same range albeit at higher levels relative to a fixed datum?
I just stepped inside for a minute. Will have to get back to you later… and hopefully with that link as well.
I haven’t come across the article I wanted to get for you - yet. However, I did come across these articles in one of the earlier instances of my multi-clipboard. Keep in mind these articles - with possibly the exception of one - are from 2015. There may be one from either 2017 or 2018. The article I want to get for you is from 2018. Still looking. Anyway, here’s the links to the ones I found so far. Notice that a couple of the articles seem to contract each other. One says glacial melting and sea level rise slows down the earth’s rotation while another article states the opposite. I think both of these articles failed to take into account the fact that the earth’s core spins at a different rate than the earth itself - and that the core is apparently spinning faster than it did a few millennia ago. I’ll keep looking… (I also included a final link to “50 Interesting Facts About Earth” which is pretty interesting in itself.