Maui, the First Island

 Getting a Taste

 Sunday, 4/23 - At the island of Maui. We had a tasting excursion at 8:15, so we got up at 6:30 and had breakfast. Had 14 passengers and a driver/guide packed into a van, driving from place to place to try various dishes. Usually, a 'tasting' is a single bite, or maybe 2, but several of these tastings involved a complete serving. John got over-heated at 1 point, and then got full at the next stop, which surprised me. The final stop was a craft brewing company that served food. John tried the 2 beers they offered for tasting, but neither of us ate our fish taco. Back at the ship, John was wiped and took a nap. Then we had supper at the skyline, which was okay. John read for a while and went to bed. I read until midnight and went to sleep.

Our room had not been made when we got back to the ship about 2. Which meant the bed had not been split. I complained - again - and someone arrived about 3 to clean it. We went to the library until about 4. It had been cleaned and the beds separated so we could use them.

 

Climbing the Volcano

Monday, 4/24 - still at Maui. Had an excursion at 8 to go to the top of the dormant volcano, supposed to be 2 to 1/2 hours, but we didn't get back until 12:30. John tried to walk the last 500 feet to the top of the peak, but only got half-way there before he had to turn around and come back or miss the bus. It was a spectacular sight, but John was running down by the time we got back to the ship. We were going to eat at the Skyline, but it wasn't open, so we went to the buffet. Listened to our voicemails on our room phone. NextCruise wanted to answer John's questions, and she would be at her desk from 2 until 4. We originally went to the wrong desk, but eventually found her. Then back to our room, where John was tired and upset. At 4, went to the talk about the next day's port, Hilo, on the Big Island. At 5:00 was a Loyalty Appreciation party. After about 15 minutes, we left to get supper. Decided to try the Cadillac Diner, but weren't impressed. John ate about half his sandwich and went back to our cabin. I finished most of my meal and went to our cabin. We talked about the luau, which was an evening excursion on Thursday, and decided to cancel our participation, so I went down and cancelled it. When I got back to the room around 7, J stopped reading and went to bed.

Permian Period Part 1

 The Permian Period is the last period of the Paleozoic Era, and it spans the 47 million years from 298.9 million years ago to 251.9 million years ago.

The Permian witnessed the diversification of two groups, the mammals (and all creatures more closely related to mammals than to reptiles and birds) and the reptiles. But I'm going to look at the conditions existing on the Earth at the time before I consider the animals that populated it.

At the time, the world was dominated by the supercontinent Pangaea, which formed when Euramerica and what was left of Gondwana collided during the Carboniferous. There was a smaller continent that lay to the northeast of Pangaea called Angara. There were also some small islands east of Pangaea called Cathaysia. Of course, with most of the land mass gathered into one supercontinent, the rest of the globe was ocean. The superocean of the time was the Panthalassa. Pangaea straddled the equator and reached for the poles (but didn't necessarily get there). This, of course, had an effect on the ocean currents of the time.

Early in this time period, Cimmeria—a string of microcontinental islands—tore off from the Gondwana area in the Southern Hemisphere and during the course of the period, moved up to join the Eurasian part of Pangaea in the Northern Hemisphere. Cimmeria included parts of today's Turkey, Iran, Afghanistan, Tibet and the Malay Peninsula. The Central Pangean Mountains, which began forming due to the collision of Laurasia and Gondwana during the Carboniferous Period, reached their maximum height shortly after the beginning of the Permian, and would have been comparable to the present Himalayas.

The Carboniferous rainforest collapse left behind vast regions of desert stretching over the continental interior. From approximately 262 million years ago to 259 million years ago, a series of volcanic erruptions in what is now China (was then part of Pangaea) led the way to an extinction event. This was compounded when a similar series of volcanic activity over a wide swath of Siberia (then located in Angara) continued to change the atmosphere. This mass extinction event ended the Permian Period, and started the next period. It was the largest mass extinction in Earth's history, with nearly 81% of marine species and 70% of terrestrial species dying. On land, it took 30 million years into the next time period for the ecosystems to recover.

Sea levels were mostly stable during the Permian, at several tens of meters (yards) above the present level. There was a sharp drop at one point, producing the lowest sea level of the entire Palaeozoic Era, roughly the same as today's level.

At the start of the Permian, the Earth was still in an icehouse. Around 323 million years ago, glaciers began to form around the South Pole, which would eventually cover a vast area of the southern Amazon Basin, Southern Africa, Australia and Antarctica. The coldest period was around 293 million years ago. By 285 million years ago, temperatures warmed, and a great deal of the ice retreated, although some glaciers remained. The Permian was cool compared to other time periods, at least until those volcanoes started pouring CO2 (a greenhouse gas) into the atmosphere.

It sounds like the Permian had a lot of diverse climates and ecosystems, right? So as long as we stayed away from that awful desert, we should be able to find a nice place to live. So let's take a look at the neighbors we'd have in the next blog.

 

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

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

https://en.wikipedia.org/wiki/Cimmeria_(continent)

Ordovician Period

When I first started reading the article on the Ordovician Period, I got to the mention of Gondwana, which made me stop and wonder, "Wait, haven't we been through this breakup before?" And the answer is yes, we have, in the blog I wrote about the Paleozoic Era, which the Ordovician Period is part of. I had to remind myself that this is not really déjà vue, that the Paleozoic Era has 6 periods to it, and my blog on the Era would have been like an overview, while the blogs on the periods would have more details. So, some of the big events, like the breakup of Gondwana, will be mentioned in both posts.

The Ordovician Period spans 41.6 million years, from the end on the Cambrian Period some 485.4 million years ago to 443.6 million years ago.

Life continued to flourish during the Ordovician Period, although there was an extinction event at the end of the period. The Ordovician Period is known for its biodiversification event, which considerably increased the diversity of life. Invertebrates, namely molluscs and arthropods, dominated the oceans, although fish, the world's first true vertebrates, continued to evolve, and fish with jaws may have first appeared late in the period. Life on land had yet to diversify.

However many meteorites strike the Earth in a year today, there were 100 times that many hitting the Earth per year during this period.

The southern continents were collected into Gondwana, which started the period in equatorial latitudes but then drifted toward the South Pole. Meanwhile, other continents, Laurentia (part of North American), Siberia, and Baltica (northern Europe), were drifting north, and Baltica started moving towards Laurentia later in the period. Another small continent, Avalonia, separated from Gondwana and began moving north towards Baltica and Laurentia.

Temperatures were mild in the early and middle Ordovician Period, but from 460-450 million years ago, volcanoes along one of the oceans spewed massive amounts of carbon dioxide (a greenhouse gas) into the atmosphere, turning the planet into a hothouse. These volcanic island arcs eventually collided with proto-North America and formed the Appalachian Mountains. [At last! I've been waiting for billions of years for the Appalachians to appear!]

Initially, sea levels were high, but as Gondwana moved south, ice accumulated into glaciers and the sea levels dropped. At first, low-lying sea beds increased diversity, but later glaciation led to mass extinctions as the seas drained and continental shelves became dry land. By the end of the period, the volcanic emissions had stopped. By then, Gondwana had neared the South Pole and was largely glaciated.

Reef-forming corals first appeared early in this period. Land plants probably evolved from green algae, first appearing in a form resembling liverworts. Fungi was also an early adopter of living on land, and facilitated the colonization of land by making mineral nutrients available to plant cells.

This period closed with a series of extinction events that are generally regarded as one major event, in which 49% of all fauna died. It is generally agreed that this event or series of events were caused by an ice age. That ice age had several pulses of increasing/decreasing glaciation. Each time the glaciation increased, the sea level dropped, killing many of the fauna that inhabited the shallow seas. When the sea levels rose during the next decrease of glaciation, there were entire families of fauna that had not survived to re-establish themselves in the shallow seas. This may have happened several times, producing a series of extinction events.

Well, now we're starting to get some place. Plants (of sorts) on land, starting to make the soil arable. Not sure about the carbon dioxide level in the atmosphere, but the meteor showers would be beautiful, as long as they didn't land too close. Hunting probably wouldn't do much good yet, but, hey, there's fish! Too bad I can't stand fish.

Maybe the next period will be even more amenable?

 

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

Archaen Eon

 

The Archean Eon is the second of the four geologic eons of Earth’s history. (The first was Hadean Eon.) During the Archaen Eon, which lasted roughly 4,000 to 2,500 million years ago, the Earth’s crust cooled enough to allow the formation of continents and the beginning of life on Earth. Sounds like a busy time, doesn’t it?

The oldest rock formations on Earth’s surface are Archean. They are found in Greenland, Siberia, Canada, Montana, Wyoming, Scotland, India, Brazil, western Australia and southern Africa, as well as other regions. Volcanic activity was much higher than it is today, producing many different kind of volcanic rocks.

The continents started to form during the Archean, although details are still being debated.  Although this is when the first continents formed, rock of this ages makes up only 7% of the present world’s land mass. Allowing for erosion and destruction of past formations suggests that only 5-40% of the present area of continents formed during the Archean Eon.

By the end of the Archean, plate tectonic activity may have been similar to that of the modern Earth. For those who know how to read it, evidence demonstrates that liquid water was prevalent and deep oceanic basins already existed.

The Archean atmosphere had very little free oxygen, yet temperatures appear to have been near modern levels. The moderate temperatures may be because of greater amounts of greenhouse gases. Or, the Earth may have reflected less sunlight and heat due to having less land area.

There is substantial evidence that life began either near the end of the Hadean Eon or early in the Archean Eon.

The earliest identifiable fossils consist of stromatolites, which are microbial mats formed in shallow water by cyanobacteria. The earliest were found to be 3.48 billion years old. They were found throughout the Archean and became common late in the Eon. Cyanobacteria were instrumental in creating free oxygen in the atmosphere, and created so much of it that later, there was a crisis of sorts, when the life that existed at the time could not cope with the high level of oxygen. (I read that somewhere and have included it in one of my other blogs, but at this time, I can’t remember where I got that from.)

It is generally agreed that before the Archean Eon, life as we know it would have been severely challenged by the hostile environmental conditions then found on Earth.

Life during the Archean consisted of simple single-celled organisms such as Bacteria.

However, fossilized microbes from terrestrial microbial mats show that life was already established on land as long ago as 3.22 billion years.

So, it was a busy time. Lots of water sloshing around, lots of volcanoes creating land masses, and life beginning to get a first grasp on the place. If we wound up crash-landing on a planet like that, could we survive? Could we cultivate cyanobacteria to create more oxygen for us? Doing that to any large extent might strip out some of the greenhouse gases, which could lower the temperature of the planet. Which only goes to show that you have to be careful what you do to make a place your home.

 

https://en.wikipedia.org/wiki/Archean#:~:text=The%20Archean%20Eon%20(%20%2F%C9%91%CB%90r%CB%88,beginning%20of%20life%20on%20Earth.

Our Sister Planet

What did you learn about Venus - sometimes called our sister planet - when you were in school? Unless you are still in school, chances are that at least some of those ‘facts’ have changed.

Venus has been called Earth’s twin, because it is similar to Earth in size and mass. Venus’ diameter is 7,520.8 miles, only 396.7 miles smaller than Earth’s. Its mass is 81.5 % of Earth’s. But in other ways, they are not very alike at all.

Venus is still the second planet from the Sun, it is still named after the Roman goddess of love and beauty. It orbits the sun in 224.7 Earth days. A Venus day is 243 Earth days, so its day is longer than its year. It also rotates in the opposite direction as Earth, so on Venus, the sun rises in the west and sets in the east. It still does not have any moons.

Venus has the densest atmosphere of the 4 inner planets, which consists of more than 96% carbon dioxide. At Venus’ surface, the atmospheric pressure is 92 times that of Earth, or roughly the pressure found at 3,000 ft underwater on Earth.

Venus is the hottest planet in the solar system, with a mean surface temperature of 863°F. Mercury is closer to the sun, but Venus is hotter. It is shrouded by an opaque layer of clouds of sulfuric acid. It may have had water oceans at some point in the past, but they would have vaporized due to a runaway greenhouse effect. That water vapor would have photodissociated, and the resulting free hydrogen swept into interplanetary space by the solar wind because Venus doesn’t have a planetary magnetic field. It is postulated that the surface of Venus is a desertscape interspersed with slab-like rocks and is periodically resurfaced by volcanism.

In my youth, I remember reading books and short stories that postulated that Venus weather included perpetual rain, and that Venus was a water planet. In both cases, humans from Earth had colonized Venus. But given the updated information on Venus’ atmosphere and surface, colonization may have to wait until some type of reclamation can happen. Perhaps remove some (a lot!) of carbon from the atmosphere, and set up some type of artificial field around the planet to keep the solar wind from removing any more of the lighter elements from that atmosphere. If we can lessen the green-house effect, then maybe the volcanism will also settle down a bit.

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

Baltica

Despite my confusion over the location of ‘the Baltic States’, they are right where normal people would expect them; along the Baltic Sea. Somehow, over the years, my mind had decided that the otherwise-un-named Baltic states were located immediately north and northwest of Greece. However, I looked them up (for the sake of this blog), and boy, was I wrong. I had put these states in Eastern Europe, but way too far south.

The Baltic States (Estonia, Latvia, and Lithuania) are in Eastern Europe, snuggled up east of the Baltic Sea and west of the Ural Mountains of Asia. And that places them right on the protocontinent of Baltica!

So, yes, this is kind of related to the Supercontinents blogs, but I’m only going to explore this one little piece of crust. Sometimes it roamed around on its own. At other times, it gathered together with other pieces of crust. Right now, it is smooshed between NorthEastern Europe and NorthWestern Asia. Will it succumb and eventually be pushed under these larger plates, or will it somehow break free again? I don’t know. But let’s see what is known about it.

The thick core of Baltica is also known as the East European Craton and is more than 3 billion years old.

About 2 billion years ago, small pieces of crust started colliding. These included Sarmatia (which was the Ukrainian Shield and Voronezh Massif*) and Volgo-Uralia. That seemed to work pretty well, so about 1.8 billion years ago, they added Fennoscandia, which included the Baltic Shield.

Now, if I’m reading the articles right, about 750 million years ago, Baltica and Laurentia (most of North America) both rotated clockwise, bumped each other lightly and headed for the south pole. At some point (possibly 650 million years ago), it is postulated that Earth became completely covered in snow and ice. (Yes, Snowball Earth.)

It turns out that Siberia was located fairly close to the South Pole, too, and it apparently didn’t take long for Siberia to completely lose its cool. According to one theory, Siberia started having some severe volcanic eruptions, and the build-up of green house gases in the atmosphere from that source resulted in a complete melt-down of all that snow and ice in as little as 2,000 years.

Anyway, Laurentia beat feet and headed north, but Baltica remained in the south at least long enough to hang around Gondwanaland. After that, Baltica drifted north and approached Laurentia again. However, around 425 million years ago, Scotland-Greenland and Norway all collided together, forcing Baltica to look elsewhere for new continental buddies.

Just when you thought you’d found a friend. Poor Baltica.

* Now a piece of Central Russia

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

https://www.google.com/search?q=baltic+states&oq=Baltic+states&aqs=chrome.0.0l6.4638j1j7&sourceid=chrome&ie=UTF-8

Cambrian Period

The Cambrian Period lasted from 541 to 485 million years ago. At the beginning of this time period, the small unicellulars that represented most life on Earth became more complex and multicellular. They also diversified quite rapidly, bringing forth the first representatives of all modern animal phyla. Indeed, there is strong evidence that all animals evolved from a single common ancestor.

Life prospered in the oceans, but the land is thought to have been relatively barren, with nothing more complex than a microbial soil crust or biofilm. A few molluscs may have emerged to browse on that biofilm, but the continents were probably dry and rocky. The global supercontinent Pannotia had just broken up during the early part of the period, and the new continents were mostly flanked by shallow seas, which were relatively warm. Polar ice was absent for much of this period.

Most land masses were clustered in the Southern Hemisphere during this period, but were drifting north. During the early portion of the Cambrian, the supercontinent of Gondwana went through some large, high-velocity rotational movements.

Trilobites (I wrote about them in an earlier post) were rampant during the Cambrian period. Possibly this was because without any sea ice, the sea level was high, which meant large areas of the continents were flooded in warm shallow seas, which is ideal for sea live. But the sea levels did fluctuate somewhat, suggesting there were ‘ice ages’, possibly meaning pulses of expansion and contraction of a south polar ice cap. Although the beginning of the period was cold, the average temperature during the Cambrian was 7° Celsius warmer than today.

Even so, trilobites were not the dominant species, as was once thought. It seemed they were, because they had hard external shells that were easy to fossilize, much easier than the thin chitinous shells of other arthropods, and so trilobite fossils were much easier to find by today’s paleontologists.

The Cambrian period is often referred to as ‘the Cambrian Explosion’, indicating a huge increase in the variety and diversity of life forms. But it seems (to me) that it might be better to think of it as ‘the Period of Great Changes’. At the start of the Cambrian, new creatures with new behaviors and lifestyles destroyed the biofilm that covered the sea floor, so all the creatures (from the previous time period) who depended on that biofilm died out.

Around 515 million years ago, the number of species dying out was larger than the number of new species coming into existence. 500 million years ago, the oceans saw a big drop in the oxygen content, and at the same time, the level of toxic hydrogen sulfide increased. Either of these events alone could produce extinctions, so imagine what happened when they came in together.

Where would hydrogen sulfide have come from? There are a few ways nature makes it, including anerobic digestion by certain biofilms in the absence of oxygen. I can’t rule that one out, but I’m somewhat more inclined to ‘blame’ volcanoes, which also produce it, probably in larger quantities and certainly can do it in oceans. Also, the heat given off by the volcano(es) would tend to drive oxygen out of the water. So, was there a series of huge volcano events 500 million years ago? I don’t know. It seems possible.

And there we have the Cambrian period in a nutshell. No fascinating dinosaurs to study, but the thought of a spinning Gondwana certainly has my attention.

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

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

A Different Place

If someone mentions New Zealand, what tidbits of thoughts race through the back of your mind? Mine include ‘hobbit films location’, ‘weird landscape’, ‘two islands’, ‘south Pacific’, and ‘near Australia’. Of course, I don’t often think about New Zealand. It’s very far away, and I’m not likely to get there soon.

A couple weeks ago, I saw a headline about a recent earthquake NZ had. It took my head a couple seconds to realize, “Oh, yeah, it sits on the other side of the ring of fire.” So, just because my curiosity was aroused, I’ve been looking into the geology of NZ.

First of all, yes, New Zealand does have two large islands, but they are surrounded by a bunch of little ones. Islands tend to come in groups, right? Seems like it to me.

The south island is home of the Southern Alps, the tallest some 12,316 ft tall. These steep peaks and the deep fjords on the southwest coast indicate the glaciation that once covered the area. Makes me shiver just thinking of the ice that was once there.

The north island is not as mountainous, but does have volcanoes, which have formed a plateau. That plateau hosts that island’s highest peak (9,177 ft) and the country’s largest lake, which sits in the caldera of one of the world’s most active supervolcanoes. Okay, that’s a little too much heat for roasting marshmallows.

New Zealand is what’s left of Zealandia, a microcontinent (half the size of Australia) that long ago broke off from the super-continent Gondwana, and then slowly submerged. It also straddles the border between the Pacific and Indo-Australian tectonic plates.

The border of these plates is most evident by the Southern Alps, pushed up and contorted by the force of the 2 plates pushing against each other. In other places, the edge of one plate gets pushed beneath the other, producing deep trenches in the ocean, most notably south of NZ, east of North Island, and 2 others further north.

So, NZ has mountains and bays once scoured by glaciers, deep ocean trenches and volcanoes. What about earthquakes? Of course! It sits on a giant fault. In fact, Wikipedia says they experience 150-200 earthquakes every year that can be felt, and almost 14,000 more each year that aren’t felt.

The headline that caught my attention not long ago was about an earthquake in November of this year; a section of seabed that had been raised 6 feet above sea level on a beach. As I researched ‘New Zealand earthquakes,’ I saw another interesting headline, this one about 3 cows that were left stranded on a ‘land island’ after an earthquake. Apparently, that earthquake caused a lot of land to collapse, leaving dots at a higher altitude with sides too steep for the cows to navigate. And possibly some tourists were also trapped on similar ‘land islands’ and had to be rescued.

Just one more way New Zealand is ‘different.’

Cheaper by the Dozen

When I was young, our solar system had 9 planets. It was a nice big family, which seemed to be fairly popular back then. And then, not long ago, tragedy struck; Pluto was demoted to ‘dwarf planet’.

On the other hand, our solar system family grew, because several other ‘dwarf planets’ were also named; Ceres in the asteroid belt, and Eris, Haumea, and Makemake in the Kuiper Belt. So right now, our solar system has 13 ‘planets’. A baker’s dozen! This year, 2 probes checked out 2 different dwarf planets, and the stuff I’ve been hearing is absolutely amazing!

Let’s start with Ceres, because it’s the closest to us. It’s only a hop past Mars.

I’m not sure I even heard of Ceres before it became a dwarf planet. Discovered in 1801, it was named a planet, then other asteroids were found in that belt, and Ceres became just another asteroid. And nobody really paid the asteroids any attention. The most respect they got was when a science fiction author included a nail-biting scene when his space ship had to negotiate the asteroid belt on its way to the outer system. Other ships might meet their doom in ‘the belt’, but not the ship the hero was on.

How would a scifi author treat Ceres now? It’s the smallest dwarf planet/biggest object in the asteroid belt. Would it be mined, like some think the asteroid belt would be? Would there be a base there? Do we know of anything important about Ceres?

Yes, we do.

Ceres has water.

No, Ceres doesn’t have rivers or oceans. But it has water and some kind of salt.

Scientists know this because of Ahuna Mons, one of the bright spots that dots Ceres’ surface. On Mars, Olympus Mons is a huge mountain. Ahuna Mons is Ceres’ biggest mountain. The probe, Dawn, took pictures to map Ceres’ surface, and they show that Ahuna Mons reaches approximately 3 miles in height. If someone wanted to drill straight through, from one side to the other, they’d have to drill for 12 miles. Walking completely around this ‘big bump’ would be a trip somewhat more than 36 miles.

Its slopes are steep and shiny. The top isn’t a point—more like a plateau with cracks.

It’s a volcano. But it doesn’t spew out molten rock; Ceres is too cold. Evidence indicates it spews a thick slush of water, salts and mud. And it’s geologically new - only a billion years old.

There are other bumps on Ceres; older slush volcanoes that are eroded and pocked by collisions. Now, your word for the day is cryovolcano, which is a slush volcano.

Can’t you see it? Our space-faring descendants taking a road trip to Ceres for a refreshing salty mud slushey. Umm, Yummm. I can almost taste it now!