anlomedad on Nostr: Oh! A few years ago, when I started to get my head around paleo climate evolution, I ...

Oh!

A few years ago, when I started to get my head around paleo climate evolution, I extensively brooded over Miller et al 2020, sea level rise. It stretches 60 million years but I only focussed the last 4Ma. Which is far, far away from the mid Miocene 16Ma.
But it does cover the accepted time when the Pacific got closed off from the Gulf of Mexico.

Sea level conveniently followed Milankovic cycles so I looked at this teamwork too.
And discovered an oddity:
In 2.73Ma, which is at the very end of the Pliocene, Miller's sea level skips a full Milankovic beat.
It should have risen and fallen according to Obliquity (tilt), a 41ky cycle. But it didn't.
It just stayed low the whole time! (And resumed its 41ky rise and fall after this hiatus.)

Wow! What a mystery!
I searched for an explanation. Was it a comet like the one that killed the dinosaurs? Or a series of volcanic explosions with a lot of cooling SO2 emissions?

That alley brought no real smoking gun. So I left the topic.
A few years later in 2024, I came across this hydrogen cloud which dented the heliosphere which exposed Earth to more cloud-seeding cosmic rays.
Opher et al: https://www.nature.com/articles/s41550-024-02279-8

You can use the slider in this app https://faun.rc.fas.harvard.edu/czucker/Paper_Figures/Interactive_LxCC.html to watch our sun's yellow dots as they encounter the red cloud in 3Ma and leave the vicinity of the cloud in 500ky.

Could that be the smoking gun for Miller's cooled-down sea level hiccup in 2.73Ma ?

How very exciting!!