I have a question? Does anyone know if former world

[leftyladyfrommo]

catastrophies have affected the oceans much? We seem to be polluting the oceans to an unprecented degree. I was wondering if natural catastrophies of the past have ever done this? Like when space chunks hit or when huge volcanoes blasted off. Did those warm up the oceans or pollute the water?

It looks like the warming of the oceans is the thing that is going to trigger all of this global chaos.

Its not nice to mess with Mother Nature.

[phantom power]

1. Yes, natural disasters also have screwed up the oceans.

In times past, the earth has been quite a bit warmer than it is now. We're headed that way again, but it's clearly a disaster for the current ecosystems, since everything is adapted to the current climate.

[jpak]

2. There have been many

~2 billion years ago, the evolution of oxygenic photosynthesis changed the redox balance of the ocean and precipitated out large quantities of iron. This process eliminated anaerobic organisms from most marine habitats. But it also gave us the stratospheric ozone layer that protected the Earth's surface from the most dangerous wavebands of UV radiation.

~600 million years ago, the reduction in atmospheric CO2 from marine photosynthesis precipitated the Proterozoic glaciations, aka "Snowball Earth". Sea ice coverage extended to the Equator and shut down most marine photosynthesis. Volcanic activity over several million years released enough CO2 back into the atmosphere to warm the planet and end this period. This was also the period where metazoan organisms arose and diversified.

The worst catastrophe was the Permo-Triassic extinctions (~245 million years ago). The ocean went anaerobic and acidic and most of the Earth's biota was eliminated. The exact cause is poorly understood, but it may have been from a bolide impact followed by massive volcanic activity.

~65 million years ago, a bolide impact killed the dinosaurs and rendered the deep ocean anaerobic.

~55 million years ago, a massive efflux of methane from the ocean caused a rapid and catastrophic warming of Earth's climate.

~5 million years ago to present the rapid evolution of hominids produced a bipedal organism that wreaked havoc on the rest of the Earth....

[phantom power]

3. nice list :-)

[leftyladyfrommo]

4. Wow! Thanks so much.

Did you happen to see the paper this morning? We had an article on the massive loss of coral reefs - some that have been there for hundreds of years - have died off in just the last couple of years. And no one really knows why? Except for increasing water temperature. And I would wonder about pollution.

And there has been a huge dieoff of seabirds off the Oregon Coast and no one knows what is causing that either. A kind of bird that lives out at sea. The populations in Washington and California seem to have not been affected.

The only saving grace is that those coral reefs are amultimillion dollar tourist industry so someone may actually try to do something to save them.