Earth's Crust Notes

95 faults earthquake

About _______ % of all earthquakes occur at or near the edges of moving plates, along the great cracks in Earth's crust called _________________. The sudden jolt of energy released as vibrations that are felt on Earth is called an __________________________

absorbed

As new crust is formed along divergent boundaries, old crust must be _____________________. If not, Earth's size would keep growing. Since the size hasn't changed, we know old crust is reabsorbed

opposite oceanic earthquake

At this boundary, 2 plates move past each other in _______________________ directions Most of these boundaries are found in ____________________ crusts Something that is quite common along this boundary type are ______________________________. Mountains can form here also

no term

Continents and oceans are on plates. Because the plates move, the continents we live on today looked different in the past and will look different in the future

200 1,000,000

Each year about _________ earthquakes around the world are large enough to cause major damage. Most are so small that people don't notice them. In fact, only scientific instruments have detected that there are about ______________________ earthquakes all over the world each

4,000, drill, hypothesize, waves, volcano

From the surface of Earth to the center is about ______________ miles. To get info about the layers scientists use tools and instruments. To get info about the crust, they use _____________ to take samples. Below the crust scientists can only ___________________ about what the layers are made of. They base them on patterns of __________ that travel through the Earth after an earthquake and on material that travels to the surface after an active _________________

convection current centimeter

Heat from the center of the Earth causes currents in the asthenosphere. Liquid rock in the mantle is warm so it rises, then it cools and sinks, warms and rises again, etc. This process of sinking and warming and rising and cooling is called a _____________________________________. As the asthenosphere flows, the plates above it are in constant motion. The plate motion is so small, just a few __________________________ a year, that we can't feel it. Only measurements detect it

crumple and fold mountains

In an continental and continental collision, the plates ____________________________. The collision forms ___________________________.

oceanic mountains and volcanoes

In an oceanic and continental collision, the _________________ plate is pushed down b/c it is denser. This collision can form __________________________________.

pushed deep-ocean trench

In an oceanic and oceanic collision, one of the plates is _________________ down under the other. The plate that is pushed down melts. This collision causes a _________________________ to form

mid ocean ridge sea floor spreading

Most divergent boundaries are formed along the ___________________________________. When magma pushes up through the crust and pushes the old seafloor away, forming new crust this is called _____________________________________

convergent

Old crust is absorbed at ______________________ boundaries

mountains erosion deposition objects 19,000

Plates move around the world forming _______________________ and causing earthquakes and volcanic eruptions. Earth's surface is also changed by the processes of ___________________ and _______________________. Also _________________ change the surface of Earth. Still another way Earth's surface is changed when it is hit by ____________________ from space. Each year, about _____________________ meteorites fall to Earth

Alfred Wegener Pangea

A scientist named _________________________ determined that long ago, all the continents were joined together into one supercontinent known as ____________________. He determined this by fitting all 7 continents together like puzzle pieces

waves

The energy from an earthquake travels away from the focus in ______________

iron, nickel, 10,000, solid

The inner core is made up of mainly __________ and _____________. It is also extremely hot. It is estimated to be more than __________________ * F. At this temp, metals should melt. However the inner core is pressed into a _____________ by the weight of all of the layers above. The outer core is liquids metals of iron and nickel.

7 asthenosphere plasticity

The lithosphere is divided into ______ major plates. All of Earth's land and oceans are on these plates. The plates float on the __________________________. The huge stiff plates float because the asthenosphere has a property called ___________________ which means it can flow.

divergent convergent transform fault

The lithosphere's plates fit together like a puzzle. Plates move away from each other along a _________________________ boundary. They collide with each other along a ____________________________ boundary. And they grind past each other along a ______________________________________ boundary

secondary right

The slower wave is called a _________________________ wave, or S wave. S waves cause vibrations at _____________ angles to the waves direction of travel (like waves that travel on a rope that is shaken up and down)

2900, 7200, asthenosphere

The top of the mantle is about ____________ * F and the bottom is about _____________ * F The ____________________________ is a zone of weak, easily deformed rock in the upper mantle

crust, mantle, core

There are 3 layers of Earth. The outermost layer is the ______________. Then there is the _______________. The innermost layer is the __________

2 primary push-pull

There are _____ kinds of waves that travel inside Earth The faster kind is called a __________________wave or P wave P waves are _____________________ waves that cause back and forth vibrations (like pushing and pulling on a slinky)

3

There are _____ types of collisions: 1) Oceanic and Oceanic 2) Continental and Continental 3) Ocenic and Continental

600 80 land

There are nearly __________ volcanoes on land Volcanoes are the chief ___________ builders Scientists estimate that ________ % of the area of the continents and ocean floors was formed by volcanoes

80 90

There is lots of activity along convergent boundaries. ______ % of all volcanoes and _______ % of all earthquakes occur along this boundary type

rocks volcanoes earthquake

Using clues from _____________, ______________________, ___________________________. patterns, scientists have formed a hypothesis about how Earth's surface has changed over the past 500,000,000 years

20, 5

We live on Earth's crust, which is about _________ miles thick under the surface of the continents and about ________ miles thick under the ocean floor

speeds inside at the surface

When an Earthquake occurs, it produces different kinds of waves that travel at different ______________, Scientists have classified two wave types: those that travel __________________ Earth and those that only travel ________________________________

Plate tectonics newer older

_____________________________________ is the theory scientists use to explain plate movement. The crust under oceans is ____________________ and thinner Oceanic crust. The crust at the continents is __________________ and thicker Continental crust

magnitude intensity Richter 8.5

Scientists can measure many aspects of an earthquake _______________________ (amount of energy released) and ____________________ (amount of damage done) The _____________________ scale measures the amount of energy released or magnitude.The largest earthquake ever recorded was ___________

magma crust

Scientists hypothesize that divergent boundaries are caused by ________________ being pushed upward under a plate. Magma melts the crust and oozes onto the surface, creating new _________________

hot spot move chain hawaiian

Sometimes volcanoes occur at a _______________________, a place on Earth where a column of molten magma pushes its way up to the crust. A hot spot doesn't move, but the plate above it does, forming a __________________. The _____________________ islands were formed from a hot spot

slower damage

Surface waves travel only at the surface and move ___________________ than S waves and P waves These powerful waves make the ground roll and sway. The surface waves are the chief cause of __________________ during an earthquake

Ring of Fire

The Andes is part of an amazingly long chain of volcanoes nearly 30,000 miles long that almost completely surrounds the Pacific Ocean known as the ___________________________

Mercalli moment magnitude

The ___________________ intensity scale measures the amount of damage done The newer, more accurate scale scientists have recently begun to measure the overall strength of earthquakes is called the ________________________________

thinnest, granite, basalt, lithosphere

The crust is the __________________ of all the layers. Samples show that the continents are made of _________________, but the crust under the oceans is made of denser _____________ The lithosphere floats on the asthenosphere and includes all of the crust and part of the upper mantle. It is the cool, rigid portion of Earth