Eg: the pictured carvings are on collapsed rock shelves, presumeably these were above normal river level when carved and in a two thousand year period the river has undercut the rock shelf and they've colapsed to below the usual river level.
In fact there are many possible reasons why your apparent smug bad faith poo poo climate change comment isn't well considered.
> the pictured carvings are on collapsed rock shelves, presumeably these were above normal river level when carved and in a two thousand year period the river has undercut the rock shelf and they've colapsed to below the usual river level.
You presume something that is not expressed in the article. There's nothing about the river undercutting the rock shelf and causing a collapse - that's an act of imagination on your part.
If you simply take out the political, environmental slant (out of the article, and your mind) and just look at what is stated, the most obvious conclusion is that every so often this river drops lower than usual. And that droughts, floods, etc have always been part of life on earth.
No idea, I was also downvoted by someone, it's not something I fuss about; you'd have to ask the downvoters.
> You presume something that is not expressed in the article.
It's right there in the pictures, layered strata, rock shelf, carvings on rock collapsed off of the shelf.
It's a pretty basic geological observation.
> I'm simply making the obvious observation - that the river got this low 2000 years ago,
That's a shallow conclusion, geologically speaking .. a leap of "can't think of anything else".
There are many possible reasons strata | water relationships might alter over the course of two thousand years. I've fleshed out one.
> take out the political, environmental slant (out of the article, and your mind)
There you go with the poor reasoning and shoddy conclusions based on projected assumption again.
My background is geophysics and my two comments are related to geology and timescales.
It isn't.
The article says:
> The rock carvings are not usually visible because they are covered by the waters of the Negro River, whose flow recorded its lowest level in 121 years last week.
There is no mention of "collapse", "strata" or "shelf". Are we looking at the same info?!?
The article ties climate change into this, when it says:
> According to experts, the dry season has worsened this year due to El Niño, an irregular climate pattern over the Pacific Ocean that disrupts normal weather, adding to the effect of climate change.
but there is no reason to think climate change has anything to do with this. The article itself also says:
> The rock carvings are not usually visible because they are covered by the waters of the Negro River, whose flow recorded its lowest level in 121 years last week.
ie 121 years ago, the river was recorded as being this low. ie before climate change.
For me this is another 'climate change' article, but is interesting as not all the claims the article makes can all be true.