Hey now, thats not true. We could excavate a canal at that scale if we were willing to use up our stock of nuclear weapons. Of course, we would probably irradiated the whole southern hemisphere to the point of issuability. But like I said earlier, you can’t make am omlete without rendering half the planet uninhabitable.
Not that any of this is practical, but could you avoid the salt buildup by having a second basin?
You have your first basin, it’s where you keep you salinity at nice levels (whether fresh or ocean level), and then a second basin that is optimized for evaporation to absorb all the salts.
For reference, at about 26 meters rise, the Panama Canal doesn’t need locks anymore.
at 150, you wouldn’t even need it. (or be able to find it.)
Yes.
150m is a huge amount of sea level rise. Assuming zero changes in inherent land elevations vs the geoid there may not even be enough water on Earth to raise sea levels that high.
And yes, the world, including the USA and CentAm would look very different w 150m of sea level rise.
My point was to illustrate the magnitude of the kind of changes needed to make Australia more like FL or Italy; a narrow bit of land near the tropical water rather than a vast parched interior. And how utterly different in scale that was from humanity’s pipsqueak capabilities or the OP’s risible copy of the Salton Sea.
Aside:
I arrived at my 150m WAG without consulting any kind of map of what various sea level changes might look like. I just found this interactive sea level rise map.
By plugging in 150m I see that value turns out to be a pretty good WAG for giving Australia a lot more coast and a lot more potential for tropical climate and tropical rainfall, while still leaving a usable continent.
And FWIW, about 2000m of rise renders Earth a water world for most practical purposes. Not that there’s enough water to do that with the current landforms. We’d have to have significant continental sinking & flattening of the overall topography above and below the water to actually get to a (nearly) water world.
Aside 2:
For a fun look at the other side of sea level changes you can’t do better than to consult the sage Randall Munroe.
Roughly a third of the continent through the Eastern parts is the Great Artesian Basin.In the Northern parts there are tropical storms which fill the Basin as the water flows South. We have rivers all right, It is just that they run under the earth. With more demands for water the level is dropping fast. We also have a person who wants to start “fracking” in our precious water storage.
There is talk of running a system of pipes from the high rainfall dams in the Far North to supply water to the South. Every couple of years lately we have gone into drought conditions and rationing.
To get a decent inland sea in Australia, you’re going to have to dig a fairly wide channel. As people upthread have pointed out, a narrow canal or pipe won’t do the trick. At a guess, the channel will have to be something like 5 kilometers across, maybe more. And it’ll have to be deep enough for a counter current to form at the bottom. That is, a current needs to flow one way on the surface and the other way below. That may keep the water from becoming too stagnant.
Ultimately inland seas work when
a) meaningful rainfall occurs over a vast drainage basin.
b) that leads to the inland sea
c) that is in turned drained by a smaller river
d) that leads to the oceans.
So you want your lake at a meaningful altitude above sea level. And by definition you need the drainage basin above that level else the drainage would flow to someplace else.
Lakes Superior, Michigan, Huron, and Erie are roughly 600 feet above sea level and Ontario is roughly 250 feet above sea level. Then the St. Lawrence flows to the ocean. Being filled by many tributaries other than the lake drainage.
Nothing about Australia’s topography supports the prereqs for an inland sea. Nor does to OP’s terraforming proposal.
The best you’re gonna do is as I suggested: sea level rise to increase the amount of coast and bring reasonably deep ocean well inland vs current shores.
??? That was all attempted for agriculture. It didn’t work. You can’t push out the lines of vegetation beyond what is defined by the climate.
The lines for commercial agriculture are not in the same place as the line for the edge of the desert, but the limitations are the same. You can plant stuff, and shelter stuff, and stabilize the soils for years, and then come years where it all dies. If stuff could live there sustainably, it already would.
No, it’s not.
The image below is from the Mallee Cliffs National Park in the centre of the area denoted as “Mediterranean Forests, Woodlands and Scrub” from your map. It’s scrub, not forest.
https://mt89b42mtr62svcyy19prhvv-wpengine.netdna-ssl.com/wp-content/uploads/2019/03/image_gallery_Wayne-Lawler_Mallee-Cliffs-1.jpg
Again no.
The Murray falls just 164m in 2,200 river miles from Albury (the western edge of the “Temperate Broadleaf and Mixed Forest” zone on your map on the NSW/Vic border) to it’s mouth in Lake Alexandria. There are no mountain gorges to dam. There are as many weirs on the rivers as can be sustained. Most of the water in the rivers comes from the precipitation falling on the western side of the Great Dividing Range.
Also, as the area is an ancient seabed (the Eromanga Sea from the Cretaceous Period) raising water tables increases salinity. It’s been the policy of water management throughout the inland regions for decades to lower water tables.
Mediterranean Forests, Woodlands, and Scrub are three different things found in the region. That photo shows one of them.
For the amount of geoengineering involved, it would be easier to scrape the high parts of Australia into the ocean and generate an equivalent amount of new Mediterranean coastline that way. Make the new land a nifty fractal shape to maximize your seafront/labor ratio.
Looking at the elevation map, I suggest that rather than building the inland sea it would be easier to just sink Australia. Once it settled to the ocean floor, the higher elevations would stick out and become islands. You know, the same thing we did to New Zealand
You mean Zealandia. But they went a little overboard on that and too much is below the sea and there’s not enough prime real estate.
If we’re going in for a serious construction project, I would suggest it would be better to scrape the low parts into more mountains. Mountains create precipitation, after all, and the scraped out low parts become a ditch that can fill with water.
Start from about Port Augusta, fr’instance, and head north? I’m sure we can get at least as many k’s done as, say, Trump’s Border Wall.
I remember this being mooted back in the 70’s. The suggestion was a bit further West, but basically that idea. It wasn’t serious of course.
Right about now I bet the South Australians are thinking “start about Mount Gambier and head north. And make it a Really Big Ditch”…
Climate affects biomes, and the reverse is also true: biomes affect climate. The most obvious way is through mediation of the energy from sunlight and the water cycle. Flora absorb sunlight differently than soil or rocks. Water is returned by flora directly into the atmospheric instead of going to the ocean. Soils created by flora and fauna absorb water differently than sand or rock.
Slowing the movement of rain to the ocean is more than damming rivers. It’s build catchments in many, many tiny watersheds so that the rain has time to be absorbed by the ground and plants, instead of running off into a stream. Once water is running, it’s going to be in the ocean sooner rather than later.
Note that I’m not saying it’s practical nor advocating it’s desirable to engineer biomes. I’m only saying it’s more sustainable than building lakes or seas.
Agreed. But at the same time …
During the 1800s settlement of the semi-arid American West there was a widely promoted but utterly mistaken notion that “Rain follows the plow”. IOW, that intensive agriculture on what had been fairly dry grassland would promote enough additional rain to in turn support that intensive agriculture indefinitely.
When the rains didn’t materialize it set in motion the destruction of the Ogallala aquifer (and others), blowing through thousands of years of groundwater accumulation in less than 2 centuries. Oops.
Said another way, biomes can be stretched only a short distance as measured on a continental scale and even then only on a timeline (much?) longer than human lives.
You have a better work ethic than I do. I only move dirt downhill.
As my great-grandpappy, the stevedore, said when the foreman complained that he was only carrying one bale off the boat when all the others were carrying two: “I ain’t my fault that they’re too lazy to make two trips!”
The Bradfield Scheme is a largely discredited project going back to the 1930’s proposed by Story Bridge designer John Bradfield (apparently he designed some other well known, gaudier bridge further south).
The Scheme proposed irrigating western Qld/Central Australia by diverting water from some monsoonal rivers in FNQ in into Lake Eyre.
Every few years some of the right wing parties/commentators propose a new version of the scheme claiming that it will establish western Qld as the food bowl of Asia.
ETA: The scheme was generally rejected by sensible people on economic, scientific and engineering grounds.
Noted that we are simply arguing the degree of impracticality of an impossible scheme.
Except in the most deluged of wet years the amount of local run off in the entire Murray Darling from local rainfall is negligible. My experience is based on my family who have lived and farmed in the eastern section of the basin for 150 years.
A natural model perhaps envisioned by the OP would be the Okavango Delta in Botswanna.
Now if you could turn Lake Eye into the Okavango you really would have a material impact on the local climate and environment.
Three key differences:
- The catchment in the Angolan highlands feeds 11 km3 (2.6 cu mi) of water flow into the delta annually, which is 10 times what flows through the Warburton once or twice a decade, on average.
- The Okavango flood waters take a month to reach the delta. The flood waters through the Coopers Creek and Diamantina Rivers may take up to a year to reach Lake Eyre, if they actually do.
- As a consequence the World Heritage listed Okavango is fresh water and one of the Seven Natural Wonders of Africa. While World Heritage listing of Lake Eyre has been proposed, the Lake Eyre Basin is the world’s largest salt pan, an ephemeral pelican mass hatchery and any proposal to keep water there permanently would simply create the Saltron Sea of the Southern Hemisphere.