Unit 6 Earthquakes and Volcanoes

Warm Up Friday Analyze this bar graph- this graph compares

deaths from EARTHQUAKES per time period

How are Richter Scales and Mercalli Intensity Scale connected?Both measure earthquakes

How are they not connected?Richter Scales measure magnitude and Mercalli Scales measure observable damage.

Moving rocks get caught on each other at faults.

Moving rocks create STRESS points The breaking point is reached Energy is released

Earthquakes1. What are earthquakes?

1. Earthquakes are movement of earth’s crust caused by plates shifting and releasing stored energy

Rocks on either side of a fault snag and build up pressure

When the rocks break ... shake, rattle and roll!

http://videos.howstuffworks.com/hsw/5934-geology-earthquakes-video.htm

Earthquakes2. What are seismic waves?

2. Seismic waves are shock waves in the earth caused by an earthquake.

Earthquakes3. What are P waves? 3. P waves are primary

waves. They are fast and longitudinal

( push and pull forces) P waves are the to 'arrive' at

a seismic station. The P wave can move through solid rock and fluids, like water or the liquid layers of the earth. It pushes and pulls the rock it moves through just like sound waves push and pull the air.

Earthquakes4. What are S waves? 4. S waves are secondary

or shear waves. They are

slower. S waves are

transverse- move from

side to side.

S waves move rock

particles up and down,

or side-to-side—

perpendicular to the

Direction of the wave.http://aspire.cosmic-ray.org/labs/seismic/index.htm

Earthquakes5. What are L waves? 5. L waves are “love waves”

Named after a British scientist who calculated a mathematical model for a wave.

L Waves are the fastest waves and move from ground to side to side. In other words, they are P or S waves that hit the surface.

Earthquakes6. What is the focus of an earthquake?

6. The focus is

where rocks first

break and move.

7. What is the epicenter? 7. The Epicenter is the point on earth’s surface directly above the focus.

Earthquakes

8. What is a seismograph?

8. A seismograph is an instrument used to record seismic waves.

Earthquake Scales9. What is the Richter Scale?

9. A Richter Scale measures the total energy released by an earthquake

b) +1 means x32

#29 Quick Quiz- Video Clips Write answers in complete sentences

1. What is one of the first signs of a tsunami?

2 : List two safety measures that Japan has implemented to reduce the damage of tsunamis.

Earthquake Scales10. What is the Mercalli Intensity Scale?

10. The Mercalli Intensity Scale is a scale that measures the intensity of an earthquake. The scale quantifies the effects of an earthquake on the Earth's surface, humans, objects of nature, and man-made structures on a scale of I through XII, with I denoting a weak earthquake and XII one that causes almost complete destruction.

http://videos.howstuffworks.com/hsw/11899-earthquakes-protecting-structures-from-damage-video.htm

Locating Earthquakes

http://videos.howstuffworks.com/hsw/9241-cleopatras-palace-alexandria-video.htm

Earthquake Zones11. Where are the 3 major earthquake zones?

11. Ring of Fire- is located around

the edge of the Pacific Ocean. Mid-Atlantic Ridge- this zone is

caused by sea floor spreading The Mediterranean –Asiatic

Belt- occurs because continental plates are colliding.

Earthquake Evidence12. Describe ground level earthquake evidence

12. Ground level earthquake evidence is side to side or up and down shifts of the ground. The earth has moved mostly slow and steady and is called creep

Earthquake Evidence13. Describe landscape evidence of earthquakes.

13. There are 5 descriptions: Slide – rapid down slope

movement of soil, debris, & rock

Scarp – cliff made by uplifted or subsided earth

http://videos.howstuffworks.com/hsw/9214-discovering-plate-tectonics-changing-earths-surface-video.htm

Earthquake Evidence13. 13.

Fissures – long cracks in soil or rock

Tsunami – an ocean wave caused by earthquakes

a) can be 30m high at the shore Buildings on loose soil have

more damage.

Quick Quiz- Video Clips:Answer in complete sentences

1. What is the first sign of a tsunami?

2 : What are two safety precautions that Japan has implemented to help reduce the threat of tsunamis?

http://videos.howstuffworks.com/hsw/25886-tsunami-the-destructive-force-of-tsunami-waves-video.htm

http://videos.howstuffworks.com/hsw/25893-raging-planet-history-of-deadly-tsunamis-in-japan-video.htm

http://videos.howstuffworks.com/hsw/25895-raging-planet-japan-responds-to-tsunami-threats-video.htm

Volcanoes1. What is a volcano?

1. A volcano is any opening in the earth’s crust that release molten rock.

Volcanoes2. What is a vent?

2. An opening through which material reaches the surface

3. What is a crater? 3. A crater is a hollowed

out area in the top of a volcano

Volcanoes4. What is the pipe?

4. The pipe is a long crack through which magma moves

5. What is the magma chamber?

5. A chamber with a pocket of magma.

Volcanoes Label the parts

Volcano Video Part I

http://videos.howstuffworks.com/hsw/19172-understanding-volcanoes-part-one-video.htm

Volcanoes6. What is an active volcano?

6. An active volcano has erupted during the last century.

7. What is a dormant volcano?

7. A dormant volcano has not erupted for hundreds of years, but it believed that it has the ability to erupt.

http://www.geocodezip.com/v2_activeVolcanos.asp

Volcanoes8. What is an extinct volcano?

8. A volcano is considered extinct if it has not erupted for thousands of years.

http://hvo.wr.usgs.gov/volcanoes/maunakea/

Volcanoes9. List the sequence of events when a volcano erupts?

9. Lava flows out –usually gently and quietly

2) Then an explosion of debris occurs. The following are products of a volcano

pyroclasts – fragments of broken rock from a volcano

ash – hot fine-grained material bombs – large molten or

semimolten chunks

http://videos.howstuffworks.com/hsw/6185-mountains-of-fire-an-eruption-video.htm

Volcanoes10. What are cinder cone volcanoes?

10. A cinder cone formed from

ash and cinders in explosive

eruptions. Cinder cones

volcanoes are smaller, coned

shaped, and steep slopes.

Example: Paricutín, Mexico

http://videos.howstuffworks.com/hsw/9221-when-earth-erupts-cinder-cone-volcanoes-video.htm

Volcanoes11. What are shield volcanoes?

11. Shield volcanoes are from

from lava flow eruptions. They

have broad with gentle slopes. An example is

Muana Loa, Hawaii

http://videos.howstuffworks.com/hsw/9219-when-earth-erupts-shield-volcanoes-video.htm

Volcanoes12. What are composite volcanoes?

12. Composite volcanoes are formed from

alternating layers of lava and pyroclasts.

Characteristics include:

They are explosive and have lava eruptions

They are large with steep slopes

Examples:

Mt. Fuji, Japan & Mt. St.

Helens, Washington

13. Case study: Pompeii 13. •79 CE•Site was not discovered until 1748•Provided archeologists extraordinary details about daily life in Roman Empire•Some believe that volcano took 2 months to completely bury the town as people were “found” wearing winter clothing in the summer, dates of minted coins and letters•Populist tourist site in S. Italy

13. 13.

14. Case study: Mt. St. Helen 14. •Erupted 05/18/1980. Caused by an earthquake on 03/20/1980.•Most deadliest and costly volcano in US history.•“Glacier mountain”•Due to the eruption, at the top of the mountain is a 1 mile long horseshoe crater.•Volcano “steamed” until January 2008

Pompeii: http://videos.howstuffworks.com/discovery/28991-assignment-discovery-pompeiis-destruction-video.htm

Mt. St. Helens:http://videos.howstuffworks.com/discovery/7161-mt-saint-helens-powerful-erruption-video.htm

Igneous Rock Features Why study? Many features formed

underground by igneous activity are at the earth’s surface by erosion.

Igneous Rock Features15. List intrusive igneous rock formations

15. Batholiths, sills, dikes, and volcanic necks.

Igneous Rock Features16. What are batholiths? 16. Large intrusive igneous rock

body that forms when magma being forced upward toward Earth’s crust cools slowly and solidifies underground.

Igneous Rock Features17 . What is a dike? 17.Magma that is

forced into a crack that cuts across layers and hardens.

18. What is a volcanic neck? 18. Solid igneous core of a volcano left behind after the softer cone has been eroded.

Igneous Rock Features

19. What is a caldera?

19. Large, circular-shaped opening formed when the top of a volcano collapses. Crater Lake is an example