Jurassic Park Period Part 2

Paleoclimate

Climate during the Jurassic was approximately 5-10 degrees C (41-50 degrees F) hotter than present time, with atmospheric carbon dioxide likely 4 times higher. It's likely that forests grew near the poles, where they experienced warm summers and cold, sometimes snowy winters. It is unlikely there were any ice sheets, as the high summer temperatures would have prevented the accumulation of snow, although there may have been mountain glaciers. The ocean depths were likely 8 degrees C (about 46 degrees F) warmer than present, and coral reefs grew further north and south by 10 degrees of latitude There were probably large areas of desert in the lower latitudes.

The beginning of the Jurassic was probably marked by a thermal spike corresponding to the eruption of the Central Atlantic magmatic province. This was followed by the Early Jurassic cool interval between 199 and 183 million years ago. ('Cool', of course, is a relative term.) Then came a spike in global temperatures of around 4-8 degrees C (39-46 degrees F) during the eruption of the Karoo-Ferrar large igneous provinces in southern Gondwana, which lasted from 183 million years ago until 174 million years ago.

During this long temperature spike, the ocean surface temperatures likely exceeded 30°C (86°F) and all the land mass between 30°N to 30°C were likely extremely arid, with temperatures in the interior in excess of 40°C (104°F).

There was an episode of widespread oceanic anoxia that is often attributed to the eruption of the Karoo-Ferrar large igneous provinces and the associated increase of carbon dioxide concentration in the atmosphere. This event had significant impact on marine invertebrates, but little effect on marine reptiles. During this time, the Sichuan Basin (of southwestern China) was transformed into a giant lake, 3 times the size of Lake Superior. Seawater pH dropped to its lowest point around the middle of this event.

This was followed by a (relatively) cool period between 174 and 164 million years ago, which was followed by a warm interval between 164 and 150 million years ago. During this warm interval, the land mass interior had less severe seasonal swings than before because the expansion of the Central Atlantic and the western Indian Oceans provided new sources of moisture to moderate the temperature. The end of the Jurassic was marked by another cool interval, which began 150 million years ago and continued beyond the end of the Jurassic.

I recently saw someone on social media poo-pooing concern over the climate changing. As they put it, the climate has been changing for millions of years. And they are right, it has been. What they fail to take into consideration is that mass extinction events have been happening for millions of years, AND the climate changes of the past have not occurred as rapidly as this one. If we want to survive this climate change, we need to use the brains we have.

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

Jurassic Park Period Part 1

 

Paleogeography

Everybody knows about dinosaurs, right? And thanks to the Jurassic Park series of movies, we all know the dinosaurs lived during the Jurassic Period. But what else is noteworthy about this geologic period? I'll try to uncover something other than various dinosaurs to study.

However, I am just as fascinated with dinosaurs as any little kid, so I'll spend some time studying some of our favorites while I'm at it.

The Jurassic Period started 201.3 million years ago and ended approximately 145 million years ago. There was, as seems so common with these geological periods, an extinction event at the dividing point between the Triassic and Jurassic Periods.

The Triassic/Jurassic extinction event seemed to be caused by the Central Atlantic Magmatic Province, which, as best I can figure out, means a lot of magma and lava was moving around in the areas currently known as northwestern Africa, southwestern Europe, southeastern North America and Northeastern South America.

The articles I read seemed to indicate that this was not just a matter of volcanic activity, that some of it could have been caused by the action of diverging plate tectonics. We are aware of the Atlantic rift, where two tectonic plates are moving away from each, allowing a large volume of magma to flow, but this is not considered a volcano. This magma movement began about 201 million years ago, and continued for about 600,000 years. It was the largest activity of this type known to man, covering roughly 11 million km².

By the beginning of the Jurassic, the supercontinent Pangaea had begun rifting into two landmasses: Laurasia to the north and Gondwana to the south. The rifting between North America and Africa was the first to happen, in conjunction with the Central Atlantic Magmatic Province

By the beginning of the Jurassic, there was flooding in most parts of central and western Europe, transforming it into an archipelago of islands surrounded by shallow sea. Beginning in the Early Jurassic, the proto-Atlantic was expanded by the "Viking Corridor" (or Transcontinental Laurasian Seaway) which stretched between the Baltic Shield and Greenland, and was several hundred kilometers wide. All during the Jurassic, the North Atlantic Ocean remained relatively narrow, while the South Atlantic did not open until later.

At the beginning of the Jurassic, North and South America remained connected, but at some point, they rifted apart to form the Caribbean Seaway, which connected the north Atlantic Ocean with what is now called the Pacific Ocean, although it was much larger back then, taking up over half the globe and was called the Panthalass Ocean.

About 183 million year ago, another magmatic event started, the Karoo-Ferrar event, this one in South Africa and Antarctica. This triggered another extinction event by causing widespread oceanic anoxia, ocean acidification and elevated temperatures. I am uncertain if these types of conditions were responsible for the Triassic/Jurassic extinction event.

Madagascar and Antarctica rifted away from Africa in association with the eruption of the Karoo-Ferrar large igneous provinces, which opened the western Indian Ocean and began the fragmentation of Gondwana.

During the Middle to Late Jurassic, the Sundance Seaway, a shallow inland sea, covered much of northwest North America.

The sea level rose and fell many times during the Jurassic, peaking at one point as high as 140 meters (462 feet) above the present level.

Wow! So much happening! And that's just the geography! This makes me wonder what else was going on!

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

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

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

The Joys of Learning

I research all sorts of science subjects in my spare time, not just to write a blog about what I've discovered, but because I enjoy learning new things. I love learning new tidbits of information that I can categorize and file in the proper drawer in my mind.

There's another aspect of my life where I find myself learning new things fairly regularly. It's the publishing portion of my life. Even though I belong to a number of groups where people talk about different aspects of publishing, every so often I find myself stuck, figuratively banging my head against a brick wall as I try to do something that looks so easy when others talk about it.

I think the first time this happened to me when I was just starting, and I was formatting short stories to be converted into e-books. It seemed like no matter how carefully I formatted the manuscript, I kept getting all sorts of error messages when I sent that first effort through the conversion software. That was where I learned the adage, "Read the guidelines, stupid." Yes, the owner of the software had a 100+ page book that he made available to users for free, and I had read the first 5 or 6 pages and figured that was enough.

It wasn't.

So I backed up a bit and read the entire book, taking special note of how to correct formatting problems. Turns out that formatting problems like I'd been having were possibly caused by file corruption created when the file has been through many, many forms of formatting. But there WAS a fix!

It sounded easy; take out all the formatting and start with a clean slate, format-wise. And getting rid of all that potentially-corrupted formatting was really easy to do, so I did it. Now for the down-side. Everything in my manuscript was now Times New Roman, 12 pt font, in body paragraphs. Now I had to go through the entire manuscript and put formatting back in: Chapter Headings and font size, centered; Title page things; back matter stuff... And once I had done that, I had to READ the manuscript and re-format anything that needed to be italicized, bolded, underlined. It was, all in all, a 4 or 5 day project, during which I got virtually nothing else done. But it works.

To this day, I cringe every time I decide I need to remove all the formatting and start over. But I do it, in order to get a good conversion to the various e-book formats. As my parents used to say, if it's worth doing, it's worth doing well.

Recently, I ran across a quick and simple method for inserting a Table of Contents. I took notes and tried it on my latest book. Something went wrong; every single paragraph of the manuscript was listed as a chapter in my Table of Contents. I tried 4 or 5 times, deleting the results after every attempt, before I gave up and did it the old way, which works for print books, but not so well for e-books.

So I backed up and re-read that style manual, looking for a better way to insert a ToC into my e-books. And I found the answer in those guidelines. Once again I had to delete all my evidently-corrupted formatting and set it up again. But 5 days later, when I followed the guidelines to insert a ToC, it worked! If I still had some flexibility in my shoulders, I would pat myself on the back! Who said an old dog can't learn new tricks?

Like I said earlier, I love learning new stuff.