The Planet Has Seen Sudden Warming Before. It Wiped Out Almost Everything

New York Times ^ | December 7, 2018 | Carl Zimmer

[trebb]

So, what did the people of the time do to cause that bout of climate change? Too many camp fires?

[Bull Snipe]

Thanks, no geologist either. Off the West coast of India is the Shiva impact (370x250 miles). No link, have to google it. Jury is still out on exactly what it is, may not be an impact site. But it dates from about the time of the Chicxulub crater and the Deccan Traps.
I would think that the Siberian Traps would have had bad impact on life. Almost a million cubic miles of basalt poured onto the surface of the planet is a little over a million years.

[rustbucket]

Off the West coast of India is the Shiva impact (370x250 miles). No link, have to google it.

Thanks. I hadn't heard of the Shiva impact. Here are two articles:

Shiva

Another Shiva article

The Bombay High (or Mumbai High as it was later renamed) in the offshore area near the Deccan Traps does contain oil reservoirs.

[Ragnar54]

"Just before the extinctions, volcanoes in what is now Siberia erupted on a tremendous scale."

The eruptions lasted 300,000 years before the estimated start date of the extinctions and covered 2.7 million square miles. But the warmists would have us believe that the carbon dioxide released by the eruptions caused surface warming. Never mind thousands of years of massive lava flows.



Note that CO2 level was not as high as it was during the Jurassic, which was known for large healthy dinosaurs.

The warmists have only 1 hammer in their toolbox, "greenhouse gases". Warming must always be explained as due to an increase in such gases.

[rustbucket]

The warmists have only 1 hammer in their toolbox, "greenhouse gases". Warming must always be explained as due to an increase in such gases.

I am no fan of the global warming alarmists and the series of modifications they have made to the temperature record of the last 100 years or so. Usually you change the theory to match the data, not the other way around.

I watched an old Nova program tonight about the Siberian Traps. The people studying the Traps claimed that the outgassing of CO2 from the massive amounts of lava caused the temperature to go up 10 degrees (Fahrenheit, I think, but I don't remember for sure), and the lava caught the large coal beds in this region to catch fire and the consequent release of methane (a stronger heat trapping gas than CO2) caused temperature to go up another ten degrees. The resulting warmer oceans killed a lot of the sea life according to their theory.

I imagine the time scale of your temperature and CO2 plot is not fine enough to show a relatively short spike in CO2 if it did happen the way they theorize. They believe the CO2 concentration reached three times the current level. They used fossil ginkgo plants from the period of the Traps' formation to estimate CO2 concentration. Ginkgo leave apparently have special pores to absorb CO2, and the researchers think if there is a lot of CO2 present the plants didn't need as many special pores. So they counted special pores on the fossil leaves.

I don't know what to make of their theory. I'm suspicious of their explanations, but the immense size of the lava flows may well be related to the mass extinctions.

Your plot seems to show an inverse relationship between CO2 concentration and temperature in places or perhaps no consistent relation between the two.

I know that rising temperatures in the ocean would cause some methane clathrates and CO2 clathrates to melt in previously cool ocean sediments, but that may be a pretty slow process. Too slow perhaps to cause a runaway outgassing or explosive release of methane and CO2.

[gleeaikin]

certainly the Little Ice Age after the Medieval Warm was concurrent with low sun spot appearances. So the MW probably had a lot of them. If you have not read the whole article you have missed all the information about the intense volcanic activity in Siberia and the effects it probably had. Below you will find the very informative Wiki article on the Siberian Traps (a thick layer of basaltic rock spewed out by huge amount of volcanic activity, over thousands of years.

https://en.wikipedia.org/wiki/Siberian_Traps

At this link there is mention of extensive volcanic activity in Antarctica on the far side of the earth from Siberia. This suggest to me that a large meteor strike(s) in Siberia could have shocked Antarctica to a great extent. It seems that the Deccan Traps of India are about opposite the Yucatan strike that killed the dinosaurs. The Deccan is as much as 6,000 feet thick and covers an area several hundred miles across. A map at the link above suggests that the area of the Siberian Traps could be as large as half or more of the lower 48 states of the USA.

[Yardstick]

LOL — thoroughly enjoyed that.

[null and void]

Ring like a bell indeed.

But imagine you are standing exactly opposite of the impact site.

The shock wave rushes out from the impact at the speed of sound in rock in all directions.

Your first clue is a problem in this scenario is when that shock wave comes at you over the curve of the earth from all directions at once.

In terms of delivered energy, you are at the focal point like an ant under a magnifying glass!

You and the ground under your feet get slammed so hard that the surrounding rock is shattered all the way down to the mantle, the energy is sufficient to slam you and pressure-liquified rock into space! (not to worry, what's left of your remains will fall back to earth).

I don't doubt that magma would flow up through the shattered rock for centuries.

All in all, a pretty bad day...

[rustbucket]

My thoughts exactly. An impact that large would cause earthquakes all over the world as the pressure waves pass by, and the opposite side of the earth where the waves converge would be the focus.

My question yesterday to my sister, the geophysicist:

Could large impact craters like the one that may have wiped out the dinosaurs 65 million years ago cause pressure waves in the crust or mantle that could have traveled through/around the earth and converged on a spot on the opposite side of the earth, possible cracking the earth there and leading to giant lava flows or volcanos where the pressure waves converge?

She is thinking about her reply at the moment. Her PhD was in geophysics but her thesis was mostly just geology, so who knows.

[null and void]

It's a bit worse than that. Magma contains a lot of dissolved gasses (think of the pores in pumice) slapping a volume of such lava would be like slamming a can of Coke down, the Jolt* would drive the gasses out of solution and provoke an eruption anywhere the shock wave cracked the overlying rock.

*All the sugar and twice the caffeine...

[null and void]

A number of moons show shattered zones opposite of major impacts. It’s similar to a coup contrecoup brain injury

[rustbucket]

When I found this thread about the Permian extinction, I looked at a chart I bought 12-14 years ago I have hanging on the wall. The chart contains extinctions, geology maps of the earth, large impact craters, plants, animals plotted against a time scale going back 4 billion years. The mass or partial extinctions correlate well with large crater impacts.

When I looked at the Permian extinction on the chart, two possible large craters were mentioned, Bedoubt and Falklands. I looked up both of them. Current thinking is that Bedoubt is not an impact crater, but Falklands might be.

I highly recommend this fascinating chart. Here is a picture of it online:

Chart

And how to obtain a current version: How to obtain chart

[rustbucket]

My sister, who is retired, passed my question to a friend at her old office. The friend came up with a short summary news article and an abstract to a paper, both of which I link to below.

https://www.princeton.edu/news/2011/10/19/impact-study-princeton-model-shows-fallout-giant-meteorite-strike

and

https://www.researchgate.net/publication/215948949_Antipodal_focusing_of_seismic_waves_due_to_large_meteorite_impacts_on_Earth

The Princeton work in the top link indicates that a model that accounts for the elliptical shape of the earth, the presence of continents, and other inhomogeneities reduces the ground motion at the antipodal point on the opposite side of the earth from 15 meters for a spherical model of the earth to about 4 meters. (Still seems like pretty big ground motion to me.)

There are interesting links in the Princeton summary news article to other findings about extinctions. And, the Princeton article makes the obvious point that continents were at different locations in the past, and that would need to be considered in estimating where the antipodal point was at the time of the impact.

[BookmanTheJanitor]

about the author:

Carl Zimmer graduated from Yale in 1987 with a degree in English