1. Volcanoes & Earthquakes

2. Do Now: Recall from Previous years
What relationships do tectonic plates and faults (fault lines) have with earthquakes?

3. Volcanoes
WHAT is it? Spot in the Earth’s crust where molten rock, volcanic ash, and certain types of gases escape from an underground chamber
Magma: name for molten rock when it’s below ground
Lava: once that liquid rock erupts from ground, flows on earth’s surface and solidifies

4. Where do you find Volcanoes?
Volcanoes can form on Land or
below the sea.
Most Form AT or NEAR Tectonic Plate Boundaries or at Subduction Zones/Convergent Boundary (one plate pushes down under the other plate)
In the US, Volcanoes mostly exist in Alaska, hot spots of Hawaii, and Pacific Northwest
Many of the Earth’s Active Volcanoes reside along an arc around the Pacific Ocean---Known as the “RING of FIRE”

5. Ring of Fire

6. Volcano:

7. Scientific Prediction?
Erupt when? When thick magma and gas build up under surface, eruptions can be explosive, expelling lava, rocks and ash into the air or may be less dramatic if less gas and more viscous magma.
Scientific Prediction?
A volcano CANNOT be Prevented BUT
can be Predicted or Monitored by early warning signs.
Thermal Imaging Techniques/Satellite Cameras: Detect Heat
Chemical Sensors: Measure Gas samples & Sulfur levels when first released-----(higher sulfur=eruption closer)
**People will have time to prepare & evacuate

8. Earthquakes
What is it? What happens when 2 Blocks of Earth SUDDENLY slip past one Another
Fault: The surface WHERE the two blocks slip
Epicenter: The point on the Earth's surface that is directly above the focus (the point of origin) of an earthquake.

9. Where? Along Tectonic Plate Boundaries is where you find most faults--can be on land or underwater
Why the Earth “Shakes”?
Edges of jagged plates get stuck while the rest of plate keeps moving. “Friction” is overcome and edges unstick. All Stored up ENERGY is Released. ENERGY radiates outward in form of SEISMIC WAVES.
Seismic Waves---Shake the earth as they move through it, then shake the ground and anything at surface.

10. More Facts:
The San Andreas Fault in California is a Well-Known in the US.
Many of the Devastating Earthquakes occur here!
TSUNAMI: a long high sea wave caused by an earthquake at plates underwater

11. Is Prediction Possible?
NO--There is no reliable way!
We can predict “Where” Not “When”
Scientists can Measure Using a:
Seismograph: instrument used to measure an earthquake’sintensity & determine location of the earthquake
But
They CANNOT DETERMINE WHEN one will occur!

12. Earthquake Overview:

13. Tsunami Formation: