Zealandia: Earth’s Hidden Continent(geosociety.org)
geosociety.org
Zealandia: Earth’s Hidden Continent
https://www.geosociety.org/gsatoday/archive/27/3/article/GSATG321A.1.htm
18 comments
"A 4.9 Mkm2 region of the southwest Pacific Ocean is made up of continental crust. The region has elevated bathymetry relative to surrounding oceanic crust, diverse and silica-rich rocks, and relatively thick and low-velocity crustal structure. Its isolation from Australia and large area support its definition as a continent—Zealandia. Zealandia was formerly part of Gondwana. Today it is 94% submerged, mainly as a result of widespread Late Cretaceous crustal thinning preceding supercontinent breakup and consequent isostatic balance. The identification of Zealandia as a geological continent, rather than a collection of continental islands, fragments, and slices, more correctly represents the geology of this part of Earth. Zealandia provides a fresh context in which to investigate processes of continental rifting, thinning, and breakup."
Is this correct? If it stays submerged, and there's magma (e.g. from a tectonic rift or volcanoes), oceanic crust will form.
NZ needs to liberate New Caledonia to unite the homeland.
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRFnh7l...
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRFnh7l...
I think we should start small, today Ball's Pyramid, tomorrow the world('s 5th largest nickel producer).
https://en.wikipedia.org/wiki/Ball%27s_Pyramid#/media/File:B...
https://en.wikipedia.org/wiki/Ball%27s_Pyramid#/media/File:B...
There was a flurry of videos about this not so long ago, trying to build some vaguely new cold war narrative about how this extended NZs territorial waters and had Geo political significance.
I just want to know if we ever fully sunk or not, and if so where the fresh water fish came from.
> where the fresh water fish came from.
genomes are funny things, sometimes they can be set up with weak points, prone to breakage, sometimes bracketing a big section with a bunch of genes that when broken out, has a hard time figuring out which way it goes back in, might get it backwards in which case the individual born has the genes but not "correctly" ordered, they are not going to have a great life and likely get eaten as slow poke runts. But it keeps happening anyway.
In 1964 there was a _very_ big earthquake in Alaska[1] extents of the seafloor were raised 30 feet out of the water and remain dry land today. In the process a number of lakes and ponds are formed of the seawater that did not make it out and gradually become fresher with the rain water runoff over time. By conventional wisdom any individual ocean going fish trapped in these ponds is doomed but the ponds are populated now with freshwater Stickleback [2]. Which seems kinda "too soon" for random isolated ponds unless birds were planting them or something.
But no, it is the large genetic inversion that forms a for the most part, a sufficient single switch to thrive in fresh or salt water depending on how it is thrown. [3] The salt water fish survived in their doomed environment long enough to spawn enough offspring that the ones with the inversion that would have been the losers were now the fittest.
So in answer to when did the fresh water fish show up? Probably immediately and we don't even need to evoke the old hedge "in geological time frames"
[1] https://en.wikipedia.org/wiki/1964_Alaska_earthquake [2] https://en.wikipedia.org/wiki/Stickleback [3] https://www.sciencedaily.com/releases/2015/12/151214165724.h...
genomes are funny things, sometimes they can be set up with weak points, prone to breakage, sometimes bracketing a big section with a bunch of genes that when broken out, has a hard time figuring out which way it goes back in, might get it backwards in which case the individual born has the genes but not "correctly" ordered, they are not going to have a great life and likely get eaten as slow poke runts. But it keeps happening anyway.
In 1964 there was a _very_ big earthquake in Alaska[1] extents of the seafloor were raised 30 feet out of the water and remain dry land today. In the process a number of lakes and ponds are formed of the seawater that did not make it out and gradually become fresher with the rain water runoff over time. By conventional wisdom any individual ocean going fish trapped in these ponds is doomed but the ponds are populated now with freshwater Stickleback [2]. Which seems kinda "too soon" for random isolated ponds unless birds were planting them or something.
But no, it is the large genetic inversion that forms a for the most part, a sufficient single switch to thrive in fresh or salt water depending on how it is thrown. [3] The salt water fish survived in their doomed environment long enough to spawn enough offspring that the ones with the inversion that would have been the losers were now the fittest.
So in answer to when did the fresh water fish show up? Probably immediately and we don't even need to evoke the old hedge "in geological time frames"
[1] https://en.wikipedia.org/wiki/1964_Alaska_earthquake [2] https://en.wikipedia.org/wiki/Stickleback [3] https://www.sciencedaily.com/releases/2015/12/151214165724.h...
NZ has never been covered entirely since it first arose.
That said, all of our endemic fish are either amphidromous (can live in fresh or salt water, bullies, and the larval phases of most galaxiids) or if not, most likely descended from other galaxiids that were - e.g., the alpine galaxias. Galaxiids are found in Australia and South Africa also.
https://niwa.co.nz/freshwater-and-estuaries/nzffd/NIWA-fish-...
> It is thought that the non-diadromous species of Galaxiidae have evolved from the diadromous species, probably after geological events caused them to become land-locked. Gradually, these species have developed separate populations and distinguishing characteristics.
That said, all of our endemic fish are either amphidromous (can live in fresh or salt water, bullies, and the larval phases of most galaxiids) or if not, most likely descended from other galaxiids that were - e.g., the alpine galaxias. Galaxiids are found in Australia and South Africa also.
https://niwa.co.nz/freshwater-and-estuaries/nzffd/NIWA-fish-...
> It is thought that the non-diadromous species of Galaxiidae have evolved from the diadromous species, probably after geological events caused them to become land-locked. Gradually, these species have developed separate populations and distinguishing characteristics.
A friend of mine said a funny thing once.
He said "in many places, if you create a man-made lake and fill it, in a couple of years there will be fish in it."
go figure.
He said "in many places, if you create a man-made lake and fill it, in a couple of years there will be fish in it."
go figure.
Wish there was a clear pic showing where it sits, disappointing
How is Figure 1 not exactly that?
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Figure 1 and 2 show it well? Also easy to Google many more images.
Wow, this seriously blew my mind. The tl;dr is that the area surrounding New Zealand (“Zelandia”) is arguably / was a continent. Fascinating!
Okay, but look at how close it is to Australia, with a narrow channel separating them.
"North America" and "South America" makes sense, because they are so close together. So why don't we rename these continents "East Oceania" and "West Oceania"? Oceania is a name for the region around Australia/NZ/Indonesia, so that seems like a happy compromise.
https://en.wikipedia.org/wiki/Oceania
"North America" and "South America" makes sense, because they are so close together. So why don't we rename these continents "East Oceania" and "West Oceania"? Oceania is a name for the region around Australia/NZ/Indonesia, so that seems like a happy compromise.
https://en.wikipedia.org/wiki/Oceania
Narrow just like the English channel if one side was in England, and the other in Greece :)
Even if they were close why would you rename them? Asia and North America are close, Asia and Europe are "close" (connected), Asia and Africa... you get the point
Even if they were close why would you rename them? Asia and North America are close, Asia and Europe are "close" (connected), Asia and Africa... you get the point
"Australia" and "Even Australier". And rename Antarctica "Australiest"
2000km is narrow? There's a reason it's called a sea, not a strait or channel.
Oceania also encompasses all the far flung Pacific Islands, so yeah, nah.
Oceania also encompasses all the far flung Pacific Islands, so yeah, nah.
Many people don't really have a idea of the sheer size of Australia. I largely blame the Mercator projection on most maps.