Hot Spots

Unit Essential Question: How does the Earth recycle and renew its surface?

Presentation Objectives: § Describe the three methods of heat transfer. § Explain how convection in the asthenosphere (lower mantle) creates the plate movement that forms the convergent and divergent boundaries. § Explain how Earth’s surface is recycled.

Finding the Plates• Knowing that the main features associated with plate

boundaries are earthquakes and volcanoes, scientists are able to “see” the plates by plotting where these features occur.

Earthquake Map

Q1

There’s Something Odd There!

The Hawaiian Islands are in the middle of a plate!

Q1 What’s So Special About Hawaii?• Hawaii is known as a hot spot.

• An unusually hot region of the Earth’s mantle where high-temperature plumes of magma rise toward the surface.

• Originate deep in the mantle or possibly near the core-mantle boundary.

• Extremely hot area produces magma that melts through the crust to form volcanoes on the surface.

• Scientists believe that hot spots are stationary.

• Always stays in the same place while the plate moves.

• As this happens, a chain of volcanoes forms.

Q2

What Is Happening Today?• There are currently 8 islands.

• Oldest = Kauai • Youngest = Hawaii (Big Island)

• Each island contains volcanoes, but all are inactive except those on the hot spot. • Kilauea, which is found on the Big Island.

• It is “perhaps” the most productive in the world.

• Scientists have recently noticed that a seamount 30 miles southeast of Kilauea is growing. • When it reaches the surface, it will

become the newest island. • Known as Loihi.

Q3Hawaiian Hot Spot: Kilauea

Other Hot Spots• While Hawaii is the most well known hot spot, there

are many that exist around the world.

• Galapagos Islands, Iceland, Azores, and...

Q4 Yellowstone National Park

Mud Pots Hot Springs

Old Faithful

Q4

What Can Hot Spots Tell Us?Since hot spots are stationary and plates move over them, hot spots can be used to determine the rate and direction of plate motion.

Which is the oldest?Kauai

Which is the youngest?Hawaii

E1 What Can Hot Spots Tell Us?

What is the relationship between age and distance from the hot spot?The older islands are farther away!

What is the relationship between height and distance from the hot spot?The taller islands are closest to the hot spot!

Kauai was over the hot spot when it formed, but it moved with the plate. Therefore, the plate must be moving to the right!

E1

Now It’s Your Turn!• Given the diagram of the Hawaiian islands and the Emperor

Seamount chain, answer the questions about plate motion.

AB

The Pacific Plate has changed direction!

E2

Hot spot