Physical Science Unit 4

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Shadow zones

the areas that earthquake waves don’t reach

Can sheer waves travel through water?

no

What is the earth made of? (compositional)

Crust - silicates

Mantle - Oxides (things bonded to oxygen)

Core - Iron

Mechanical layers of the earth

Lithosphere: where the crust is, rigid

Asthenosphere: what drives the plate tectonics (like silly putty, partially molten peridotite)

Mesosphere: solid, get a lot of magma

Outer core: liquid iron layer

Inner core: completely solid

How do we understand the earth’s layer?

1. Observation

2. Mass & Density of earth

3. Meteorites

4. Seismology (shows shadow zone)

5. Magnetism (iron convecting layer)

The temperature at which a material loses its magnetism.

Curie Temperature

Meteorites that are believed to be similar to the material that formed Earth and other planets in the solar system.

Stony Achondrites

Minerals that contain silicon and oxygen bonded together

Silicates

The __________ of an earthquake is the point on the Earth's surface directly above the focus.

Epicenter

A break in the lithosphere of the Earth along which earthquakes have occurred.

Fault

The point at which earthquakes originate.

Focus

What best describes the chemical composition of Earth's crust/core?

Granite and basalt / iron and nickel

From the average density of Earth, we know that

Density increases with depth in the earth

The shadow zone for P waves provides evidence for

Density changes at earth’s mantle-core boundary

From the center to surface, the chemically distinct layers of Earth are:

Core, mantle, crust

Convergent

When two plates run into each other

• C-C

  • Mountains

  • Earthquakes

• O-O

  • Island Arcs

  • Volcanoes

  • Earthquakes

• O-C

  • Mountains

  • Volcanoes

  • Earthquakes

Divergent

O-O

• Volcanic activity

• earthquakes

C-C

• Volcanic Activity

• Earthquakes

Hotspot

Like Hawaii

Big mantle plume, plate goes over it and build volcanoes and makes islands

The theory that the ocean floor widens as the mid-ocean ridge separates.

Seafloor Spreading

An extinct group of seed plants that arose during the Permian through the Triassic Period.

Glossopteridales

An ocean island that has no remaining central volcanic edifice, but exists only as a coral reef almost completely at or below sea level.

Atoll

A curved line of volcanic islands all (or almost all) of which contain active volcanoes

Island Arc

A straight line of islands of volcanic origin where only the largest island contains an active volcano.

Linear Island chain

A line of underwater volcanic vents that marks a diverging plate boundary.

Mid-ocean Ridge

Uniformitarianism

Laws today are the same as they were a long time ago

Superposition

The rock on top of another rock is younger

Inclusions

Little rocks in big rocks

little rocks are older

Intrusions (crosscutting)

Spike of rock coming across a rock. Spike part is youngest

Faunal Succession

Similar to superposition but with fossils

A subdivision of geologic time. Smaller than an era, it is usually several tens of millions of years long.

Period

A type of radioactive decay clock that uses the trails of tracks created by uranium fission decay to determine the age of geologic events

Fission-track dating

Determining the sequence in which events occurred relative to each other.

Relative Time

A chart that breaks down geologic time according to the animals and plants that were found in each division.

Geologic column

A numeric or quantitative measure of time.

Absolute time

An extinct group of paleozoic sea creatures that had shells.

Ammonite

Sedimentary

Layered rock

Metamorphic rocks

when sedimentary rock is heated underground

Igneous

Comes from within the earth’s crust, comes up with lava

Metamorphic → Igneous

Melt

Igneous → Sedimentary

Erode + Deposit

Metamorphic → sedimentary

Erosion → deposit

Sedimentary → Igneous

Melt

Sedimentary → Metamorphic

Heat + Pressure

Igneous → Metamorphic

Heat + Pressure

Types of Igneous Rocks

Intrusive: cool inside the earth

Extrusive: rocks have already cooled on the earth

Differentiate based on the size of their crystals: cool slower in the earth, so bigger crystals

A sinkhole can form in limestone when water dissolves the limestone. Which of the following best describes this type of weathering?

Chemical Weathering

What does chemically combining with water do to the melting temperature of rock?

Decreases the melting temp

Alluvial Fan

Stream coming down from a mountain

Evapotransportation

When plants absorb water

If something is V shaped

A river has cut through thereIf

If something is U shaped

Some type of glaciation has happened

The most important erosional agent of the hydrological system is which of the following?

Running Water

Feedback Loops

Can be + (increases warming) or - (decreases warming) (reinforcement)

(sweating + shivering)

The Earth radiates as much energy back into space as it receives from the Sun.

True

Which of the following can be used to estimate temperatures in ancient climates?

The thickness of tree rings in ancient wood

Largest body in the system

Sun, everything rotates around it

Gas giants

Jupiter

Saturn

Uranus

Neptune

Triangulation

Measuring stars that are on our side of the galaxy

Mercury

Closest to the sun

sunbaked

other side- ice cold desert

Venus

Same size as earth

Oven baked acidic place

Jovian Planets

Jupiter (huge) (red spot)

Saturn

Uranus (blue)

Neptune

(lower density, bigger)

Terrerstial Planets

Venus

Earth

Mars

Mercury

Nebular Hypothesis

Solar system was rotating gas, it collapsed in on itself

Spins due to angular momentum

• Sun only allowed rocky stuff to form (Terrerstial)

Is the nebular hypothesis fusion-centered

NO, just for the formation of the solar system

A model of the solar system where the Earth is at the center.

Geocentric model

Method that can only measure distance to planets in our solar system.

Radar and laser ranging

Considered the better model of our solar system because of Occam's razor.

Heliocentric model

What conditions led to the difference between jovian and terrestrial planets?

Jovian planets formed in the colder outer regions of the disk where the temperatures were low enough for low-density materials like water and methane to form solid ices.

How are stars made

fusion → nebula gets sucked in by its own gravity and makes a dense mass and releases a lot of heat

Star’s life cycle (low-mass star)

Stellar nebula

low mass star

Red giant

Planetary nebula

White dwarf

black dwarf

Star’s life cycle (high-mass star)

Stellar nebula

high mass star

red supergiant

supernova

neutron star

black hole

ALL STARS CYCLE

Molecular cloud

Proto star → fusion

Main-sequence star

• Hydrogen-hydrogen: releases energy, star puffs outwards

Red giant phase

• <.1<9 masses = small

Brown Dwarf

When a protostar is <.1 solar masses

H-R Diagram

Average of star’s colors compared to their brightness

Calculates distance to distant stars

The space between stars.

Interstellar medium

Beginning phase of a star when gravity begins to condense the surrounding matter.

Protostar

Process that provides a star's energy.

Nuclear fusion

Remnant of a star composed entirely of neutrons because gravity pulled the electrons into the protons.

Neutron star

Neutron star that emits precisely-timed bursts of radio waves and high-energy x-rays.

Pulsar

Gas that glows from being heated by a nearby hot star.

Emission Nebula

Glowing bubbles of gaseous material that expand out from a small star into space.

Planetary Nebula

Cool layer that the star's light comes from.

Photosphere

The final stage of a very massive star that no longer emits light and pinches off the space-time region.

Black hole

A collection of gas that is too cold to emit visible light. The gas does emit low-energy radio waves.

Dark Nebula

The small hot core that remains after a small star forms a planetary nebula. The star is about the size of Earth at this stage.

White Dwarf

In this stage, the star expands to about 50 times its normal size.

Red Giant

The name of a white dwarf after it cools and no longer emits energy.

Black Dwarf

When a star collapses and rebounds, creating a massive shock wave that destroys the star.

Supernove

How did our universe get created?

A primordial atom exploded

A constant introduced by Einstein into his equations in an attempt to cancel the predictions of an expanding Universe.

Cosmological constant

The galaxy of over a hundred billion solar masses to which our Sun belongs.

Milky way

An observed relation between the recessional velocity of a galaxy and the distance to that galaxy.

Hubble Law

A small group of about two dozen galaxies that is associated with our Milky Way.

Local group