Mountains, Volcanoes, & Earthquakes images

The effects of plate tectonics:


Moving plates of Earth's crust cause massive alterations to the landscape.  The three biggest effects of plate tectonics are:



Mountain formation

This unit will look at each of these in more depth.


Let's start with volcanoes:

There are two types of volcanoes because there are two types of magma:

The two types of magma are Mafic and Felsic

Mafic                                                                                           Felsic

From the core                                                                           From melted seafloor

Hotter (1200 C)                                                                         Cooler (600 C)

Thinner                                                                                      Thicker

Darker                                                                                        Lighter

Flows (friendly)                                                                         Explodes (dangerous)

Shield volcano                                                                          Stratovolcano

Found at divergent boundaries and hot spots                   Found at subduction zoens of convergent boundaries

Made of heavy metals                                                             Made of sand and shells


Rock Density Lab Objectives: - ppt download

Rock Density Lab Objectives: - ppt download

Rock Density Lab Objectives: - ppt download

Mafic Vs. Felsic Rocks: Know the Difference - Science Struck

Igneous Rocks-(Extrusive-Intrusive-Mafic-Felsic - YouTube



Now, let's look more closely at Mafic...


The magma is molten core and oozes up from Earth's interior until it breaks through the surface and erupts.

This molten core is composed of mostly heavy metals and is loosely bonded.

Image result for magma from core


This hot molten rock is loosely bonded so the gases escape and the lava flows.  It looks like this:

Image result for mafic lava

Image result for mafic lava

You can step on lava : gifs

Earth, Portrait of a Planet, Chapter 9 Flashcards | Quizlet



That flowing makes a gentlly shaped volcano called a "shield volcano" that looks like this:

Image result for shield volcano


You will notice that this type of magma is hot, dark, thin, and friendly.  They are found where molten core breaks through the surface (divergent boundaries and hot spots).


Hot spots:

Image result for hot spots, hawaii



Now let's look closer at felsic...


Felsic is melted sea floor which is found at subduction zones of some convergent boundaries.  It is light colored, cooler (600 C), but much thicker which means the gases bring the lava with them when they explode out (think shaken soda can).

Image result for subduction zone

Chapter 7 Section 2 Volcanic Eruptions. - ppt video online download


Image result for pyroclastic flow

Mount Vesuvius - ArcGIS StoryMapsByzantine Military: 536 A.D. - The Worst Time in History to Be Alive


When this ash settles back down, the volcano forms a classic shape called a "stratovolcao":

Image result for stratovolcano





Sometimes the magma doesn't erupt.  When that happens, the molten plume gets called an "igneous intrusion."  They are worth looking at more closely:

Image result for igneous intrusion

Dikes, Sills, Laccoliths, and Batholiths are important.







Earthquake GIF - Earthquake Nepal - Discover & Share GIFs
Simply put all an earthquake is is anything that shakes the earth.  There are millions of earthquakes each year resulting from the crustal plates sliding past one another.

Image result for earthquake waves

Note the Focus and the Epicenter

The focus is the center of slippage.  The epicenter is the place located above it where the earthquake is most felt.


The energy released travels in the form of waves:

3 waves | Earthquake, Earth and space science, Secondary school scienceSeismic waves — Science Learning Hub

P-waves are the fastest and go through anything.  They are compressional (like sound).

S-waves are second to arrive and go through only solids.  They are transverse (like light).

Surface waves are last to arrive (if at all).  They only travel a short distance and only at the surface of the Earth.  They do all the damage.  They are Love or Rayleigh waves.  


We can measure these waves with seismograms:

Image result for earthquake waves

You need three of these readouts for each of the three dimensions and three stations to triangulate where the earthquake was.


But some places don't feel the earthquake.

        Any guesses why?




Which country has a shadow zone area where earthquake does not occur? -  Quora

Notice the Surface waves only travel a short distance and the S waves cannot travel through the core.

The S-waves do not go through liquids and so die at the outer core.  This tells us that the core is liquid.

The P-waves get bent at the cores and, as you can see, have an band around Earth that they do not reach.



There is a lot of energy released when the Earth shakes:

Image result for earthquake energy


It is measured:

Related image

Notice that slope.  What that means is that each number is 10x as strong as the previous number!


Earthquakes are very damaging for many reasons.  They may occur anywhere and at any time, they knock buildings over, they sever water and gas lines creating fires and preventing putting them out, they crumble roads and bridges making getting to help a challenge, they can knock down dams causing flooding and cutting back on water sources even more, they can break sewage lines contaminating water; they shake your very soul increasing depression.





The third effect of tectonic movements is mountain formation...

There are three processes that create mountains.  They are convergent collisions of continents, volcano production, and dome mountains.


Continent collision:

Convergent Boundaries Flashcards | QuizletWhich is a convergent boundary that does not have a subduction zone? - Quora

We have learned about this already, but the two chunks of continent thrust upward (and downward) making the crumpled mountains (i.e. Himalayas)




Image result for volcano creation:

We have learned about these already as well.  Whether the melted rock is coming from the core (mafic) and forms a rounded shield mountain or whether it is melted seafloor at a subduction zone (felsic) and forms a pointy stratovolcano with steep sides, the mountain is made from this lava.



Dome mountain:

Image result for dome mountainDome mountains | Outdoor ottoman, Earth science, Outdoor furniture

Yes, that is a laccolith that bulges the land above it.  It produces a mountain or mountain "range" that is dome shaped:

Image result for adirondack mountain range

You will notice that this is when the magma does not poke through and creates a dome like mountain or even a mountain "range."




Quick review:

Contrast Mafic and Felsic
    How hot?
    Where found?
    Volcano shape?
    Danger level?

Define the igneous intrusions

Describe the three types of earthquake waves

What are the three mountain making processes