Does the last month of school seem to drag on for ages? Does it feel like an entire year? How about the last 30 minutes? I’m sure it feels like you have half a day left until you’re out. To you and I, 30 minutes might seem like a long time but to the earth, that is nothing. Actually, there is really no comparison that I could make because 30 minutes is absolutely nothing when it comes to the Geologic Time Scale.

WTF is the GTS?

So, what exactly is the Geologic Time Scale (GTS)? Well, it was developed so there could be a time reference for rocks and fossils. This was before the development of absolute dating techniques, which includes using radiometric dating. Through these methods, it has been estimated that our planet is roughly 4.5 billion years old! The GTS is actually quite useful; it’s used to shed light on the times on the planet and their relationship with the events that have occurred on our planet, such as the KT Boundary which indicates the Cretaceous-Tertiary extinction event which was a mass extinction that occurred in a short amount of time, with respect to the GTS.

The idea behind the GTS has been around for many years (with respect to non-geologic time) and has been continued to be perfected. However, Nicolas Steno developed the principles behind the GTS: the strata are laid down one after another with each layer being a kind of slice of time. Additionally, he proposed the law of superposition, which was that you could pick a stratum, any stratum, and the stratum below it would be older and the one above would be younger. Although they were simple concepts, they were revolutionary to earth science and they were difficult to apply to it to the real rocks. Naturally, as both human and geologic time wore on, we began to realize more and more about the strata and it’s relationship with the GTS. The strata sequence were often eroded or distorted in some manner once it was deposited which did make it difficult to connect time and strata together. Geologists also realized that even though a particular stratum had been laid down at the same time around the world, it could look completely different from other parts of the stratum. Also, the strata represent the different parts of the planet’s history. Anyways, enough of this, I am going to list the different parts of the GTS (I will write other articles going over the various parts in a more in depth manner. I’m just trying to give an overview of the GTS right now).

I guess I will go ahead and introduce/briefly describe the different parts of the GTS. There is a lot of material within the GTS so I’ll try my best to keep it short, sweet, and to the point.

Supereon

The GTS is broken up into different units of time, the largest being the supereon. There is one supereon: Precambrian, which lasted from the creation of Earth until about 4500 million years ago (mya). For the record, I will write more articles that describe the specific time units.

Eons

This is the Geologic Time Scale. Image courtesy of WIkimedia Commons

Next we have eons. They make up the supereon. There are 4 different eons: Hadean, Archean, Proterozoic, and Phanerozoic. The Hadean was the first eon and began when the Earth was created and ended roughly 3.8 billion years ago (bya). Next came the Archean eon, which started 3.8 bya and ended 2.5 bya. The Proterozoic followed the Archean and started 2.5 bya and ended 543 mya. This is followed by the current, the Phanerozoic eon, which started 543 mya and continues to this day. So, we are chilling in the Phanerozoic eon. When might this change to another eon? I’m not sure but something that would cause a change in the way the Earth is would have to occur. This is usually what prompts the transition to a new eon.

Eras

After eons, we have eras. Eras are what make up the eons. I won’t go into the dates of the eras because there are so many eras in the GTS. In the Hadean eon, we have the Cryptic era, Basin Groups, the Nectarian era, and the Early Imbrian era. After these eras, we have the eras found in the Archean eon: Eoarchean era, Paleoarchean era, Mesoarchean era, and the Neoarchean era. The eras found in the Proterozoic eon are: Paleoproterozoic, Mesoproterozoic, and the Neoproterozoic. Although there are not a lot of eras in this eon, the eras last for a long time, even with respect to the GTS. Also, if you have not noticed, there is a general pattern about these eras: they are usually able to be divided into paleo-, meso-, and neo-. Paleo- is the oldest, meso- is the middle (you will find the prefix meso- comes up a lot in meteorology), and neo- is new. Anyways, back to the eras. The final set of eras come from the Phanerozoic eon, they are as follows: Paleozoic, Mesozoic, and the Cenozoic. We are currently living in the Cenozoic era. The reason this is not called the Neozoic era is because the said era is the era of “New Life,” seeing that this is the era with the highest amount of animal, plant, fungi, etc activity and with the most diversity. Additionally, there is more life being created each day.

Periods

After eras, we have periods. Now, there are a lot of periods in the GTS and they actually begin not during the Hadean or the Archean eons but instead in the Proterozoic eon. So, let’s begin. In the Paleoproterozoic era there are four periods: Siderian, Rhyacin, Orosirian, and Statherian. In the Mesoproterozoic era there are three periods: Calymmian, Ectasian, and Stenian. Like the Mesoproterozoic era, the Neoproterozoic era has three periods: Tonian, Cryogenian (this name comes from the possibility that Earth was essentially a giant snowball at the time), and Ediacaran. These are all of the periods found in the Proterzoic eon. In the Phanerozoic eon, there are a total of 13 periods. It starts with the Cambrian period. This is found in the Paleozoic era, which has seven periods: Cambrian, Ordovician, Silurian, Devonian, Carboniferous/Mississippian, Carboniferous/Pennsylvanian, and Permian. Now we enter the periods found in the Mesozoic era, which there are three: Triassic, Jurassic, and Cretaceous. These are commonly known as the time of the dinosaurs. After the Mesozoic era, there is the Cenozoic era which has three periods as well: Paleogene, Neogene, and the Quaternary. We are currently living in the Quaternary period. It’s a pretty nice period if I say so myself.

Epochs

Okay, so I know this is getting a bit ridiculous, but I have two more GTS units of time left. The first is the epoch, which makes up an era. Epochs begin in the Cambrian period, which if you remember, begins in the Paleozoic era which begins in the Phanerozoic eon (sorry but consider it a little bit of a review). So the Cambrian period is made up the Early epoch, Middle epoch, and you guessed it, the Furongian epoch (tricked you there). You know what, I’m just going to do this in a list form from now on because there are way too many epochs.

Cambrian period: Early epoch, Middle epoch, ad the Furongian epoch.
Ordovician period: Early epoch, Middle epoch, and Late epoch.
Silurian period: Llandovery/Alexandrian epoch, Wenlock epoch, Ludlow/Cayugan epoch, and Pridoli epoch.
Devonian period: Early epoch, Middle epoch, and Late epoch.
Carboniferous/Mississippian period: Early epoch, Middle epoch, and Late epoch.
Carboniferous/Pennsylvanian period: Early epoch, Middle epoch, and Late epoch (Are you beginning to see a trend?).
Permian period: Cisuralian epoch, Guadalupian epoch, and Lopingian epoch (Yeah, about that trend…).
Triassic period: Early epoch, Middle epoch, and Late epoch (Okay, the trend is back).
Jurassic period: Early epoch, Middle epoch, and Late epoch.
Cretaceous period: Early epoch, Middle epoch, and Late epoch.
Paleogene period: Paleocene epoch, Eocene epoch, and Oligocene epoch.
Neogene period: Miocene epoch and Pliocene epoch.
Quaternary period: Pleistocene epoch and Holocene epoch (We’re currently living in the Holocene epoch).

Okay, so the ages are a bit ridiculous, no joke. So, we are not going to worry about them right now. Just know that you are currently living in the Atlantic/Subboreal/Subatlantic age. There you go. Did you catch all of that?

When you think about Earth, at least the non-atmospheric portion of it, you get the image of a big round ball of rocks and water. That, to a certain extent is true. But what is on the inside of our planet aside from a wonderful personality. Is Earth just a shallow ball on the inside that is waiting to collapse in on itself or it’s it composed of different layers that in turn are composed of different element and compounds? If you were to guess the latter of the two ideas then you would be correct. Either way, I still think you should read this article.

So, I will start off by listing the different layers of the Earth and then will go more in depth as we proceed through the article. The Earth is composed of four basic layers: crust, mantle, outer core, and inner core. Each of these layers are vastly different from each other and are always changing, sometimes very violently, as time continues. The first and outermost layer is called the crust. This is the ground you walk on or the ocean floors. The second layer is the mantle. This layer is the thickest of all the layers (when the outer and inner core are not combined). The core is what follows the mantle. The core can be broken into two layers: the outer core and the inner core.

Starting from outside and going inward: crust, upper mantle, lower mantle, outer core, and inner core.

As mentioned earlier, the crust is the outermost layer. It is made up of two types of plates: continental and oceanic. As you scan the crust, one would find that it varies in its thickness, ranging from roughly 5 km to 70 km thick. The locations where the crust is thicker is the continental plates whereas the thinner portions are the oceanic plates. Earth’s crust is mainly a composition of alumino-silicates, which are minerals made of aluminum, silicon, and oxygen.

The second layer is called the mantle. The mantle is roughly 2900 km thick and can be divided into the upper mantle and the lower mantle. A majority of our planet’s internal heat can be found in the mantle.     Because of this heat, convection occurs which allows for plate tectonics to take place (I will discuss that in another essay). In the upper mantle there exists what is called the asthenosphere. This part of the mantle is soft and plastic. Pressure is the cause for its characteristics. On top of the asthenosphere is the lithosphere. This layer can both include the uppermost regions of the mantle as well as the crust. The lithosphere is what is broken up into the tectonic plates. I will talk about the stress that is placed on it later when I do seismology. The mantle is composed of Fe,  Mg, Al, Si, and oxygen silicate compounds. In the mantle, the temperatures are extremely hot, ranging from roughly 500 to 900 degrees Celsius and increasing to well over 4,000 degrees Celsius as you approach the core.

The third layer is called the outer core. The outer core is roughly 2300 km thick and made up of a nickel-iron alloy which is in its liquid form. The temperatures in this part of Earth’s interior can soar to around 6100 degrees Celsius. As I mentioned earlier, the outer core is composed of nickel-iron alloy which is able to influence the Earth’s magnetic field due to eddy currents, or Foucault currents, which help to protect us from the solar winds that the Sun emits. Additionally, the reason this alloy is not solid is because the pressure is not strong enough to make it so.

The last layer is the inner core. This solid layer of the planet is the innermost and hottest part of Earth, with temperatures possibly reaching the temperatures as the surface of the sun. It is thought to be composed mainly of iron, this being based off of the abundance of chemical elements in the solar system.

This concludes my article about the layers of the Earth. I will go into the mechanics of seismology in a later article. Thanks for reading!

Photos came from Wikimedia Commons.

CO₂NSEQUENCE 09

Clean Energy Jobs Now. Or Pay Later. Doesn’t this sound too good to be true? A society where “eco-jobs” flourish while the usual environmentally unfriendly jobs begin a decline into the abyss. Ah… I like the thought of it. And you should too! This too-good-to-be-true idea is within your grasp. As they put it “YOUR VOICE CO₂UNTS.” If you cannot tell by now they are pretty big on the idea of CO₂ emissions and don’t you think it’s clever to put a 2 anywhere there is a CO? I think so, but that’s just me. Basically, the goal of CO₂SEQUENCE is to establish a detailed and well thought out energy and climate plan which will result in clean energy job, or “ecobs” as I call it, less pollution in the environment, as well as a secure America. If we as a nation and as a world fail to act there can be devastating consequences. These consequences do not only apply to our environment and its future, but to our economy, security, and even the human race (health factors, etc).

In order to send our message to Congress about this ever increasing problem, CO₂NSEQUENCE is educating and organizing the people, especially the youth, in the effort to vote for an eco-America. By doing so, this movement hopes to create millions of “ecobs,” reduce our dependency on foreign oil,  and save our environment in order to try to reduce the effects of Global Climate Change.

If you go to the site (click the hyperlinks) you will find that you can register yourself to receive emails from CO₂NSEQUENCE that notify you of the progress that we are making as well as events that are happening in the world as well as in your own town. You will also find that there is a challenge on the site. It is called the Organize to Be Heard Challenge. What this consists of is raising awareness about the energy and climate problems, getting people involved, informing your politicians about the problem, and getting it fixed. There is a point system that is used based on what you do to help. You can have people sign a petition showing that you are ready for the change. You could start a phone drive and call residents of your town or state and your politicians and inform them of the change that is needed. You can even go as far as to organize a rally and have the media notice the event and broadcast it on television. It really does not matter what you do to get the point across as long as we progress toward the right direction.

Remember, the youth of the world will lose and suffer the most if we do not start taking steps in the right direction. But it does not have to be that way. The youth have so much to gain from the opportunities presented in a new clean energy economy and a healthier planet. Do you want to see the world spiral downhill and have those to come live in what will become a desolate wasteland? I wouldn’t. And this is why the CO₂NSEQUENCE Movement receives the MPSN Seal of Approval.

I leave you all with a quote from CO₂NSEQUENCE: Standing together we cannot — and will not — be ignored.

Thank you for your time.

Sincerely,

Josh Bregy and Mother Nature

Summer Solstice Sunrise over Stonehenge

Ok, this post is about our atmosphere, which is key in our survival.

What is Earth’s atmosphere made up of? If you said oxygen then you are partially correct. Our atmosphere is a complex system that is composed of many different gases, not just oxygen. In all reality, oxygen only makes up roughly 20% of our atmosphere. Nitrogen is the most abundant gas in the atmosphere, making up roughly 79%. Other gases include: Argon (.93%), Carbon dioxide (.038%), Neon (.0018%), Helium (.00052%), Methane (.00017%), Krypton (.00011%), Hydrogen (.000055%), Nitrous oxide (.000030%), and so on and so forth.(If you want to know more about the gases from the perspective of chemistry then ask Mitchell Peters. If you want to know more about the gases from an atmospheric point of view, then read on for a general explanation of them. Depending on what you want, I might write something on atmospheric chemistry later on.)The interactions between these different gases help sustain life on our lovely planet. Aside from enabling you and I to exist, the interaction of these gases allows the atmosphere to absorb most of the ultraviolet solar radiation rays to the point that exposure to them is not lethal (by this I mean a short exposure, not long periods of time.  By exposing yourself to the UV rays, especially without skin protection, you can harm your body and increase your risk for skin cancer). The atmosphere also helps to regulate the temperature of the Earth, which makes it so we do not burst into flames during the summer from the sun or freeze instantly during the winter from the lack of sun. It also regulates the weather and different climates of the world.

So, how is the atmosphere structured?

The atmosphere is composed of four main layers with three boundaries that separate the different layers. The four layers are called the troposphere, stratosphere, mesosphere, and the thermosphere. The boundaries that separate the layers are called the tropopause, stratopause, and the mesopause.

Troposphere:

The troposphere is the bottom layer of the atmosphere that begins at ground level and extends to roughly 5 to 10 miles (8 to 16 kilometers) in the air. Its height is lowest at the poles and highest at the equator.The troposphere is where all of our weather takes place: clouds, storms, winds, etc. It is very rare for clouds to penetrate the troposphere and mix in with the stratosphere but this can occur with particularly violent storms where the top of the cloud or system is strong enough to develop a cap and punch through the layer. But a majority of the time the atmosphere is stable enough where this does not occur. As you go further into the troposphere both pressure and temperature will drop. I am more focused on the temperature fluctuations and not so much on the pressure but just so you know, the pressure at the top of the troposphere is 1/10 of the pressure at ground level. Now, obviously temperatures at ground level will vary with your location and elevation but as you go higher up into the troposphere, there is a roughly 4 degrees Fahrenheit drop in temperature for every 1000 feet (7 degrees Celsius per kilometer). Depending on your location, the top of the troposphere can drop to temperatures ranging from roughly -49 degrees Fahrenheit (-45 degrees Celsius) at the poles where the troposphere is thinner, to roughly -105 degrees Fahrenheit (-75 degrees Celsius) at the equator. Additionally, the troposphere can divided into six zonal flow regions that are called cells and are the cause for atmospheric circulation which create the prevailing winds. Basically, here is what you should know about the atmosphere: it extends from the ground to roughly 5 to 10 miles (8 to 16 kilometers), as you go higher in the troposphere the temperature decreases, and this is where all weather phenomena occurs.

Tropopause:

This is the boundary that separates that troposphere and the stratosphere. Basically,  at this point the temperature stops dropping. The temperatures here are still very low and reach -70 degrees Fahrenheit (-58 degrees Celsius).

Stratosphere:

This is the layer that is above the troposphere. It extends roughly 30 miles (50 kilometers) above the surface of the Earth. Unlike the troposphere, the temperature actually increases with height, with the the maximum temperature reaching roughly 40 degrees Fahrenheit (4 degrees Celsius). This is because there are many interactions between many atmospheric chemicals and the stratospheric ozone absorbs much of the ultraviolet radiation. Additionally, the oxygen content is lower in this layer than in the troposphere. Another interesting thing about the stratosphere is that a secondary circulation is generated that is crucial in the movement of such things as ozone and water vapor. This circulation is called quasi-Biennial Oscillation and is located above tropical regions. Gravitation waves that are generated by convection in the troposphere help to create and move the QBO.

Stratopause:

This is a boundary that separates the stratosphere from the mesosphere. In this boundary, the temperatures still increase, much like the stratosphere.

Mesosphere:

This layer is what follows the stratosphere and reaches a height of 50 miles (80 kilometers). Temperature decreases as the you go higher in the mesosphere and can drop as low as -99 to -130 degrees Fahrenheit (-73 to -90 degrees Celsius) depending on your location and the season. The mesosphere helps to prevent a very large majority of the meteors that hurtle towards us from actually hitting us. So many meteors are burned up in this layer because they collide with the billions of chemical particles that causes enough heat to burn up the meteors, among other things that are trapped by Earth’s gravitational field. Fun fact: Noctilucent clouds occur in the mesosphere. Not much is known about these clouds except that it is primarily composed of water particles and is thought to be associated with climate change. They are very difficult to see; they are best seen when illuminated by the sun from below the horizon.

Mesopause:

This is yet another boundary in the atmosphere. It separates the mesosphere from the thermosphere. At this point, the temperature stops decreasing.

Thermosphere:

This layer reaches a height of roughly 120 miles (190 kilometers) above the Earth. Temperatures increase as altitude increases in the thermosphere. Actually, the temperatures can reach roughly 2,700 degrees Fahrenheit (1,480 degrees Celsius). This is because there is such a high amount of solar radiation present and so little oxygen in this layer. This radiation electrically charges particles which allows many radio waves to be bounced off and can be received elsewhere.

Exosphere:

This is the outermost layer of Earth’s atmosphere. This layer can extend to 600 miles (960 kilometers) above the Earth. Temperatures are still very hot in this layer but they are still lower than those in the thermosphere. Because there is a large lack of gravity, many gaseous particles are able to escape into space. Also, satellites orbit here.