GEOLOGY

Credit: NASA

Credit: NASA

Orion Nebulae

Credit: Stardate.org

Where did the earth come from?

Most societies have creation stories (“myths”)

You can read some here

http://www.gly.uga.edu/railsback/CS/CSIndex.html

Much of this course can be thought of as the creation story as told by the science of our civilisation.

Once upon a time (13.7 billion years ago, approx.) there was a small lump of tremendous mass and temperature in the middle of nothingness… and then

This is called the Big ____ Theory

http://www.astro.ucla.edu/~wright/cosmology_faq.html

Very rapidly, space-time comes into being and expands, subatomic particles appear and form _____, great clouds of matter roam the vast universe.

All stars form from clouds of gas and dust which roam our universe. Eventually, gravity causes the cloud to collapse; since the cloud is _________, material falls in along the "poles" faster than it does near the "equator". This flattening results in a disk-like object.

Material slowly wends its way into the center of this disk, forming a new star. While the star continues to grow, lumps form in the disk which will ultimately become ________.

Credit: NASA

The disk eventually thins as more material falls onto the star and the protoplanets. A hole in the disk near the star forms as material is completely incorporated into the star and planets.

Now fully formed planets exist within the hole, even as new planets are still under construction in the outer parts of the disk

Ultimately, the remaining dust clears completely, leaving a fully formed _______________ like our own.

Credit: NASA

See video at http://cougar.jpl.nasa.gov/HR4796/anim.htmlCredit: NASA

How do we know this???

Did anyone ever SEE this???

It sounds like somebody’s dream animated with lame special effects.

Except that it comes from scientists (albeit government scientists).

So, what is science?

Is it a thing, a person, a process?

Our definition for now – the accumulated ideas of “modern” (our) civilization about how things work – what causes what, why it rains, why we get sick, etc.

The “Scientific Method” – a codification of the process of applying _________________ to answering questions about how things work.

The scientific method is basically a repeating _____ of observing, questioning, hypothesizing, experimenting, observing, etc.

No one knows when this got started.

Or when it is going to end.

observe

question

hypothesize

experiment

For example, why can’t you tickle yourself?

observe

question

hypothesize

experiment

You notice that you can’t tickle yourself

You wonder why you can’t tickle yourself

Then, you think of an hypothesis, a ________ answer (reason why you can’t tickle yourself).

Then, contrive an experiment to test your hypothesis - predict a new observation and then arrange things so you can make this new observation.

If the scientific method is a cycle, how does it ever result in knowledge?

observe

question

hypothesize

experiment

provisional answers

Scientific knowledge is the accumulation of provisional answers to questions, answers that have _______ the process of repeated cycles of the scientific method – that have not been ___________. Well tested answers become “______”.

This is what I LOVE about science, and what drives many people CRAZY.

Scientists are always qualifying statements, equivocating, defining terms, and in general avoiding whenever possible drawing any definitive conclusions about anything that matters.

Why?

I think it is because scientists are acutely aware that

KNOWING ≠ ______

Our knowledge about the world tells us we (humans) are sentient beings on the planet earth that are collectively constructing knowledge. That knowledge assumes there is a world “out there” that we can know, part of which includes that very knowledge and the brains (and books, etc.) that generate and sustain that knowledge, but is much more than that knowledge, that transcends it.

So I claim the scientific view assumes that the real world is _________________________, and that our knowledge is an attempt to create an imitation (“model”) of it, and further that this model (“world view”) is necessarily “under construction”.

Moreover, based on long hard experience, it is hard to avoid the (provisional) conclusion that the real world is very complex, and that our model of it is not only incomplete, it is ________, and wrong in fundamental ways, and perhaps can’t possibly be ______ (which doesn’t prevent it from being fairly powerful - from our perspective).

With this view, it is understandable why scientists

1. ________ about almost everything when questioned, yet

2. Devote their lives to persisting in this _________ quest to perfect the model

Current scientific knowledge is a great human achievement, similar to a great pyramid. It is vast, integrated structure and a true collective creation.

Giza, Egypt

Tikal, Guatemala (Mayan)

Scientific knowledge should be internally consistent

For example, Biology* – study of life

Is built on and is a subset of

___________ – the study of atomic/molecular interactions

Is built on and is a subset of

_________ – the study of the fundamental components of reality

_________ in Biology should contradict anything in Chemistry or Physics.

*including Medicine and Agriculture

All are originally subsets of Philosophy – the search for a rational explanation of everything.

Similarly, the earth sciences, like Geology, are based on chemistry and physics and consistent with them.

The same is true for all the disciplines that focus on humans, like Psychology, Anthropology, Sociology, Economics, Political Science, etc. These fields are also consistent with and increasingly tied directly to Biology, Chemistry and Physics.

In order to arrive at what you do not knowYou must go by a way which is the way of ignorance.

-T.S. Eliot, “East Coker”Some readers, I am afraid, will conclude from the title that I intend to recommend ignorance or to praise it. I intend to do neither….There are kinds and degrees of ignorance that are remediable, of course, and we have no excuse for not learning all we can. But… our ignorance ultimately is irremediable …some problems are unsolvable and some questions unanswerable. The extent of our knowledge will always be, at the same time, the measure of the extent of our ignorance.

Because ignorance is thus a part of our creaturely definition, we need an appropriate way: a way of ignorance, which is the way of neighborly love, kindness, caution, care, appropriate scale, thrift, good work, right livelihood. Creatures who have armed themselves with the power of limitless destruction should not befollowing any way laid out by their limited knowledge and their unseemly pride in it.

The way of ignorance, therefore, is to be careful, to know the limits and efficacy of our knowledge. It is to be humble and towork on an appropriate scale.

-from the preface

Now, back to our story….

See video at http://cougar.jpl.nasa.gov/HR4796/anim.htmlCredit: NASA

Atoms and molecules within the nebula combined to form larger particles. The ___determined what kinds of particles could exist. Close to the Sun, solar heat vaporized ices and prevented ________ elements, like hydrogen and helium, from condensing.

The inner zone was dominated by ____________, which clumped together into ever-larger bodies, called planetesimals, eventually forming the______ inner planets: Mercury, Venus, Earth, Mars.

Credit: Stardate.org & NASA

So, we really are the __________________

In the solar system's outer region, though, it was chilly enoughfor ices to remain intact. They, too, merged into planetesimals, which in turn came together to form the cores of the giant planets. _______ and _______ contain the largest percentages of hydrogen and helium, while Uranus and Neptune contain larger fractions of water, ammonia, methane, and carbon monoxide.

And yes, we are now “seeing” many of the stages of this

The point is, the process of solar system and planet formation determined basic aspects of the composition of the planet – including the abundance and distribution of ____________.

This sets both the _________ as well as ______ on what can occur on earth, along with many other factors.

As the earth formed it congealed into layers, with elements distributing into the different layers

The hot inner ______ is surrounded by a semisolid ______ below a thin, solid outer _____ on the surface

2-9/2-8

Note: 1st number is text figure (9th)/second is number is 8th edition

As the earth enlarged during condensation, the increasing mass resulted in increased _______, raising the internal temperature (4000o C in core)

In this semi-liquid state, elements distributed according to _______, heavier elements to the core (Iron, Nickel), lighter elements to the surface (Silicon, Magnesium, Aluminum) which formed the outer crust.

Periodically, _________ from the interior distributed core materials in layers on the surface, so these elements also exist in the crust today.

Recall – the elements are different kinds of atoms – each made up of 3 types of particles – protons (big, positive charge), neutrons (big, no charge), and electrons (small, negative charge). For charge balance, the number of protons and __________ is equal. “Weight” of an atom, as well as its identity, is due to the numbers of protons and __________.

Interesting that all elements are made of the same ingredients, but have very different properties.

Gases were released also during this densification stage and further through the crust through ________ venting, producing the atmosphere.

The early atmosphere was probably high in ___________, hydrogen, carbon dioxide, carbon monoxide, nitrogen, ammonia, methane and other gases. No _________.

There were no oceans until the surface cooled enough for water to stay in a liquid state.

At this point (4 BYA), the surface of the world was starting to look like a place we would recognize today – land, sea and sky.

And still a very dynamicplace geologically

The crust, the outer layer, is in two zones1. The ________ crust – underlying the continents2. The _______ crust – underlying the oceans (71% of surface)

Lithosphere – the crust plus the underlying solid layer of the mantle.

Asthenosphere – lower portion of mantle, melted rock – flows slowly

Heat from the core causes the molten rock of the asthenosphere to rise toward the surface. This can create __________ flows below the lithosphere

__________ cells result when cooler rock near the surface flows toward the center

Movement in the asthenosphere induces movement in the solid lithosphere, which is divided into huge sections called ___________ plates (15). The movement of the plates is slow (a few cm. per year)

This movement is the cause of continental drift, the long term changes in the position of the continents.

Where has Lexington been?

http://www.calstatela.edu/faculty/acolvil/plates.html

This movement causes the plates to interact with each other in 3 ways – separate, collide, slide past each other. These interactions cause various geological features, including mountains, ridges and trenches.

Oceanic ridge at a divergent plate boundary – material from the mantle is added to the plates

Trench and volcanic island at a convergent plate boundary. One plate rides up and other is driven down – subduction.

Transform faultconnecting two divergent plate boundaries. Most are in oceanic plates

t

Note the mid-oceanic spreading trenches and multiple transform faults

Convergence of plates is an important cause of mountain building, as the continental plate compresses and folds as it rides up over the subducted plate. Also material scraped from the overridden plate can accumulate. In addition, volcanoes often occur in these zones. The Himalayas and __________ mountain ranges were formed in this way.

extinctvolcanoes

extinctvolcanoes

magmareservoir

centralvent

magmaconduit

SolidlithosphereSolidlithosphere

Upwellingmagma

Partially moltenasthenosphere

Volcanoes occur where molten rock (magma) from the earth’s interior emerges through an opening in the lithosphere.

Ongoing volcanic activity contributes gases to the atmosphere, elements to the lithosphere, and islands and mountains to the landscape.

Beautiful & Dangerous

And creative

The ________ islands are being formed by the Pacific plate moving across a “hot spot” –volcanism in the middle of a plate (rare).

Earthquakes are shock waves generated by the sudden movement or ”slippage” of plates at boundaries and faults.

They can create strong vibrations in the crust and have secondary effects on the land and water.

Many of these faults are in the ocean, but some are on land, including the New Madrid fault zone that includes Western Kentucky

Fake photo

Earthquakes under water can induce shock waves in the water, called “tsunamis”, aka “tidal waves”.

Such an event occurred Dec. 26 2004 in the Indian Ocean

They can move extremely fast, more than 500 mph, and travel for miles inland from the coast.

Tsunami Japanese term (literally meaning "big wave") now generally used for an unusual, very large wave or series of waves. Tsunamis are generated either by submarine earthquakes, by landslides or by effects of volcanic eruptions (such as the collapse of a caldera in the sea). Tsunamis have long wavelengths and small wave heights on the open sea. As water depth decreases near land the wavelength diminishes and the wave height increases dramatically which may lead to catastrophic flooding of coastal areas. Tsunamis may deceive coastal residents in that a wave trough may a arrive before the first wave crest.

http://www.phuket-tourism.com/tsunami.htm

The Rock Cycle

The Lithosphere is made of Rock – the cooled surface crust of the earth. It varies greatly from place to place in the world and is a complex mixture of elements and compounds, especially minerals.

Minerals are naturally occurring compounds with a _________ structure. More than 2000 have been identified as distinct minerals. They can be very beautiful and are the source of many of our “resources”.

http://www.wilenskyminerals.com/MINERAL_PHOTOS.html

Rock is formed directly in the cooling of the crust, but once formed, it is subject to the dynamic forces already discussed, and also weathering.

Weathering refers to the breaking down of rock into small particles, which results from physical and chemical forces such as ________, grinding, flowing water, oxygen etc. Plants and __________ also contribute actively to weathering.

These smaller particles are then subject to being washed or blown away, a process called erosion. This process can wear down mountains, and also build soil. The eroded particles can be transported to a new location by gravity, wind or water, and collect in areas of ___________.

Devil’s Tower, WY

Three rock types – based on method of formation –igneous, sedimentary & metamorphic.

1. Igneous rock is the original rock, and the bulk of the earth’s crust, resulting from the ________ of magma. It is continually being formed by upwelling of magma, creating granite, lava, pumice, basalt, etc.

2. Sedimentary rock is formed from deposition of ___________ particles, often underwater (sediments). As these deposited layers get buried, they can become fused to form distinctly layered rock –limestone, shale, sandstone (common in Kentucky).

3. Metamorphic rock, forms when rocks are buried and experience ____ temperatures and pressures.

Limestone => MarbleShale => SlateSandstone => Quartz

2-29

Rock cycle – all of these rock types are subject to the dynamic action of plate tectonics, volcanism, subduction, weathering, etc. As a result, each type can be, and is transformed into the other types, creating a cycle of transformation of rock in the lithosphere (see fig. 2-29).

Even rock is ultimately a dynamic process

Mining

Mineral resources are dispersed throughout the crust, some places richer than others. They must be mined.

They are ____________

Copper mine (open pit)

Large amounts of crust must be processed to obtain relatively small amounts of mineral –solid waste and disturbance of the landscape

Often toxic chemicals are released (acids, mercury, arsenic)

Coal mining shares many of these problems

A classic “tradeoff”

Paradise – John Prine

When I was a child my family would travelDown to Western Kentucky where my parents were bornAnd there's a backwards old town that's often rememberedSo many times that my memories are worn.

Chorus:And daddy won't you take me back to Muhlenberg CountyDown by the Green River where Paradise layWell, I'm sorry my son, but you're too late in askingMister Peabody's coal train has hauled it away

Well, sometimes we'd travel right down the Green RiverTo the abandoned old prison down by Adrie HillWhere the air smelled like snakes and we'd shoot with our pistolsBut empty pop bottles was all we would kill.

Repeat Chorus:

Then the coal company came with the world's largest shovelAnd they tortured the timber and stripped all the landWell, they dug for their coal till the land was forsakenThen they wrote it all down as the progress of man.

Repeat Chorus:

When I die let my ashes float down the Green RiverLet my soul roll on up to the Rochester damI'll be halfway to Heaven with Paradise waitin'Just five miles away from wherever I am.

Repeat Chorus:

End