Geology exam 1

What is geology

The study of the Earth, the materials of which it is made, the structure of those materials, and the processes acting upon them.

How old is the planet

A conscience of scientific inquiry is concluding that the planet is about 4.6 billion years old and riding along in a universe that is about 14 billion years old

Science is

a PROCESS  know limitations and understand that hypotheses and theories change as verifiable data changes

How are the points broke down for this class

This class is 170 points total, each exam is 50 points, 4 exams total lowest of 3 dropped, final is mandatory. Term paper is 20 points

Consilience

The linking together of principles from different disciplines especially when forming a comprehensive theory.

Sophistry

• The use of reasoning or arguments that sound correct but are actually, false.

Who is the easiest person to fool

yourself

What explains how the sun works

radioactivity

Humans are…

•  frail and exist in an ecological niche - a narrow range of parameters required for specie survival 

We are part of…

• a much larger world that until relatively recently, humans did not know existed 

Our personal experiences are based upon…

• our senses and our senses are very narrow in effectiveness and range detection

Technology has expanded…

• awareness of the universe

You can feel acceleration and deceleration but not

speed

Earth rotates about

1,000 mph at equator

Galileo and his recognition of inertia

As articulated by Newton’s Laws of Motion a body at rest stays at rest but a body in motion stays in motion

Earth orbits the sun at approximately

•  66,000 mph (106,244 kmph).

Sun (and solar system) orbits galaxy at about

 500,000 mph (804,670 kmph)

During the time of today’s class we have all traveled about

 625,000 miles (1,500,837 km)

Marie Tharpe

was a research unit of the earth institute at Columbia University in Palisades New York, she assisted her father when she was not allowed to work.

What did Marie Tharpe do?

plotted data points from sonar data in the ocean floor.

x=

EQ Foci

A consilience of data reveals…

the rift valleys were also the sites of Eqs. In fact lots of EQs. 

What did Marie Tharp’s boss tell her?

she told her “boss” about the ridge system and he said it was “girl talk”.

What did Marie Tharp find?

the Mid atlantic ridge which circles the planet

What types of rocks are in the ocean?

Overwhelmingly volcanic rocks

What are the rifts in the mapping of the ocean?

fissure (linear) volcanoes

What is the longest mountain range on the planet

The mid atlantic oceanic ridge, and it is mostly underwater

Since the 1940’s what did we learn about the oceanic crust (bedrock)?

it is almost entirely volcanic

Volcanic rock records…

magnetism when it solidifies

Oceanic crust is…

denser and hotter than continental crust

Which crust is younger?

Oceanic is younger than continental

The Earth has a magnetic field and…

it flips (switches polarity) over geological time

average person lives?

700,000 hours

What do we currently know about the earth?

• It’s layered – and it’s a bit messy and not perfect layering

• • It’s hot and has a blisteringly hot interior

• • Convection cells move heat energy and magma

• • Magma “captures” or “freezes” evidence of the earth’s magnetic field and age when the magma cools below the “curie” point

• • It’s radioactive which makes it hot and in a lot of cases, age-dateable

• • It’s OLD about 4.6 + Billion years

• • It MOVES! The surface usually moves slowly, but sometimes quickly

Plate tectonics

•  A theory developed and synthesized in the 1960’s (Drummond Matthews, Fred Vine, Lawrence Morley (1963)) – You have seen and heard these names before.

4 basic concepts, 1:

• The lithosphere is made up of rigid units called plates

• • Lithosphere made up of 7 major plates (good idea to know the ones touching North America!) and numerous minor plates

• • Plates are made up of oceanic and continental lithosphere

• The oceanic plates are denser than the continental plates.

4 basic concepts: 2

• the plates move

• • Boundaries between plates are:

• – Divergent – Where plates move apart

• – Convergent – Where plates collide

• – Transform – plates move past one another in opposite directions (horizontal movement via Transform Faults)

4 basic concepts :3

• Most of the world’s large-scale geological activity occurs AT or NEAR Plate Boundaries

• • Volcanic eruptions

• • Earthquakes

4 basic concepts: 4

• The interiors of plates are relatively quiet geologically, with far fewer and milder earthquakes than occur at plate boundaries 

• BUT, Sometimes you can get a whopper quake in the middle of a plate– it’s unusual but it happens.

Much of the water on this planet and in your bodies is…

older than the solar system

Elements forming the minerals and compounds in your body are…

• “star stuff” formed in the nuclear furnace of a supernova predating the birth of our sun

 The earth’s inner structure is far more complicated than being only “liquid;”some portions are…

 solid and semi-solid

How hot is the core

11,000 F

Glaciologists are pushing the chronology boundaries back…

700,000 + years

The atlantic ocean is…

currently increasing in size

The pacific ocean is…

decreasing in size

what type of fault is the San Andreas fault?

transform fault

What are the types of plate boundaries

• Trench at convergent boundary

• Oceanic ridge at divergent boundary

• Transform fault at transform boundary

• These processes ALL occur across the planet simultaneously. It’s a recycling system. 

Divergence at

the ridges

Convergence at

the trenches

What’s a transform fault

where plates or parts of plates slide past each other

Mantle Convection Drives…

Divergence and convergence

Diverging ridges

most in ocean basins

The slab is

• “cold” relative to the underlying lithosphere/mantle material 

• Density of down-going slab acts as a heavy weight 

• Anchor-like 

• LOTS of linear (fissure) volcanos and mostly relatively small earthquakes here!  Often called “spreading centers” 

The atlantic basin is…

getting bigger

transform boundaries are

faults

Fault

• where two plates meet and slide mostly parallel past each other. The fault-ends terminate in either a Convergent Boundary (subduction zone) or Divergent Margin (spreading center).