Earth Science Exam 1

What is the Law of Uniformitarianism?

What’s happening now is what happened in the past. THE PRESENT IS THE KEY TO THE PAST

What is the Pattern and Process paradigm as used in earth science?

Helps us understand things that happened that we are not able to observe in the present.

What are some examples of using pattern to interpret process?

Can’t see granite cooling, have to presume based on observation of rocks. Rocks at scratch gravel with crystals must have cooled down slowly

What is a scientific theory? ..versus a ‘Law’ ..versus the everyday language meaning of ‘theory or theoretical’?

A theory is a consistently proven hypothesis, but not to the point of a law since all exceptions have not been ruled out or excluded. A scientific law has ruled out every exception

What is the most important element when using the scientific method?

The questions/having multiple questions

What is a hypothesis – and why do you want multiple hypotheses?

Proposed explanation(s) for a phenomenon. Multiple hypotheses helps a scientist rule out alternative explanations and reduce bias to achieve an objective answer

What is Force of gravity?

An attractive force between two objects of mass

What is weight? Mass? Density?

Weight is measure of gravitational force exerted on an object, Mass is the amount of matter in an object, Density is the amount of matter or mass per volume

Can you write out the formula and EXPLAIN the variables and what they mean?

F = G(m1m2) / (d2), G = 6.673 x 10-11 Nm2, M = each objects mass, D = distance

How changing different variables will change the force of gravity? Examples?

Increasing distance decreases force, decreasing distance increases the force, skydiver speeds, Increasing mass increases force, decreasing mass decreases force, Bowling ball falling vs feather

What is the difference between ‘Big ‘G – gravitational constant and ‘Little g’ – acceleration due to gravity. Understand these concepts and how they work….be able to EXPLAIN!

Big G in the constant of Gravity (6.673x10-11) Nm2, Is constant across the universe, tells the exact strength of gravity anywhere

Little g is the acceleration due to gravity on earth, Result of the force formula, only on earth with mass 1 being object and mass 2 being the earth

What IS energy? (definition).

The ability to do work

What is Work?

Applying force over a distance, implying motion

Can you name, explain and provide examples of the five forms of energy?

Kinetic Energy: Energy in motion, a runner; Potential Energy: Stored energy, runner waiting to start;

Wave Energy

Travel in waves, seismic waves from an earthquake also sound and light

P waves change their velocity through liquid

S waves do not pass through liquid, can pass through solids

Heat Energy

Moves more to less or hot to cold, not efficient

Transferred in Conduction, Convection, Radiant

Energy of Mass/Matter

Radioactive Material

Nuclear decay

Can you give examples of energy is transformed from one type to another?

Potential can change to kinetic energy

Transform boundary and a fault, a slip causes release of energy

1st Law of Thermodynamics – define and describe (examples!)

Energy never created or destroyed, does change form

Landslide waiting, moving, resting, creek moving

2nd Law of Thermodynamics (THREE parts ….how do they apply to Earth Systems??)

Heat always moves more to less, or hot to cold (magma gets cold going to crust during subduction/tectonic cycle)

No transformation of energy is 100% efficient (forest fire)

Food to energy in body, log to heat in fire

Heat is often given off

In a closed system, no energy in or out, will tend towards disorder, or entropy (room gets messy when not maintained)

Heat Energy:

Can you explain: convection, conduction, radiation….and give examples?

Convection

Through fluids and gases,

Requires: heat source, fluid, temperature gradient

Boiling (ignore air)

Conduction

In solid objects, vibrational energy, Floor burn

Radiation

Wave form, heat from sun, microwave food

Why is convection so important on earth, and to plate tectonics in particular?

Acts as a thermal engine for earth, powers atmospheric process

Can you explain convection in terms of: conditions required under which convection occurs, what is actually happening on a molecular level?

Heat expands, then cools and goes down also because of gravity

Can you draw and label a diagram that illustrates the process convection and explain in detail (and in words) what is happening? - how heat gets transferred and how matter gets moved around? Why do I say that “heat doesn’t rise’? How would you explain that to someone (who is not me!).

Particles more contracted then pulled down with gravity

What is steam? Water vapor? Boiling?

Steam: Water vapor (gas) produced when liquid water is heated enough to evaporate/boil.

Boiling: When liquid water reaches its boiling point and changes into a gas throughout the liquid.

Water vapor: Water in its gas state; it is invisible

How old is the universe?

About 13.8 billion years old.

How did we estimate its age?

By measuring the expansion of the universe and using the ages of the oldest stars. The cosmic microwave background also provides evidence.

How did we get from the Big Bang to Earth?

Big Bang → atoms → stars → heavier elements → galaxies → Sun → planets → Earth. Stars formed first and produced heavier elements that later became part of planets.

How and when did Earth form?

Earth formed about 4.54 billion years ago from dust and rock orbiting the young Sun. Small pieces collided and stuck together (accretion) until Earth grew.

What important Universal Law is likely responsible?

Gravity. Gravity pulled matter together, forming stars, galaxies, and eventually planets.

Some accretion, stars and supernovas, heavy element, planets with heavier elements came closer, lighter element planets strayed further out.

Also due to gravity

Earl elements helium and hydrogen, united into stars, when they went supernova, that created heavier elements

Can you DRAW and label the main layers making up the inside of the planet

Silica increases going out from the mantle

Going closer to the core, magnesium, iron become richer

Inner core solid, iron and nickel

Outer core liquid, iron and nickel

Mantle solid

Athenosphere

Earth's Layers

Inner core:

Solid; mostly iron and nickel.

Outer core:

Liquid; mostly iron and nickel.

Mantle:

Solid but slowly flows; mostly silicate rock with iron and magnesium.

Crust: Solid rock; continental = granite-like, oceanic = basalt.

Core → surface: Materials generally become less dense and more silicate-rich.

How did it get this way?

Early Earth was hot/molten, so dense iron sank and lighter materials rose (differentiation).

How do we know?

Mainly through earthquake seismic waves. P-waves travel through solids/liquids; S-waves only through solids.

Magnetic field:

Created by moving liquid iron in the outer core; we experience it with compasses and auroras.

Lithosphere:

The crust + rigid uppermost mantle; broken into moving tectonic plates.

What are the two TYPES of crust on the surface of Earth? In what four ways do they differ from each other?

Density Ocean is 3g/cm continental is 2.7g/cm

What is meant by MAFIC and what is FELSIC?

Mafic

Magnesium and iron, tends to be dark minerals

Felsic

Lots of silica minerals, lighter minerals