1. September 18 to September 22
Volcanoes Week 2
September 18 to September 22

2. Wk. 2 Day 1 Before: Question of the Day During: Notes After: Exit Slip
What 3 factors control the style of a volcanic eruptions?
During: Notes
After: Exit Slip

3. Three Types of Volcanoes
Shield
Cone
Composite

4. Volcanoes
Shield Volcano: A broad volcano with gently sloping sides, quiet eruptions, silica-poor lava. (ex. Hawaiian Islands)

5. Shield ( Basic) Cone Mauna Loa Hawaii -USA Layers of Lava Lava Flow
Shield Volcanoes are enormous features
built up only from layers of lava. They
produce lots of lava but they tend not to
erupt violently.
Mauna Loa Hawaii -USA
Layers of Lava
Lava Flow
10,000m
250 miles
Composite volcano to scale

6. Volcanoes
Cinder Cone Volcano: steep sided volcano, explosive eruptions that throw lava and rock in the air, silica-rich lava (ex. Paricutin in Mexico)

7. Ash and Cinder Cone Paracutin - Mexico Volcanic Bombs Layers of Ash
The volcano is built up of layers of ASH. When it erupts it is normally with great explosive force.
Volcanic Bombs
Layers of Ash
and Cinder
3,000m
Pipe

8. Volcanoes
Composite Volcano: a small volcano, both quiet and violent eruptions
(ex. Mt. St. Helens)
Also called “stratocones”

9. Composite Cone Mt St Helens - USA Crater Pyroclastic Flow Ash layer
The volcano is built up of alternate layers of LAVA and ASH. They can explode with great violence.
Crater
Pyroclastic Flow
Ash layer
Dyke
Lava Layer
Flank
eruption
Conelet
Lava
Flow
Crust

10. Volcanic (lava) Domes
A volcanic dome is created when a body of viscous lava slowly pushes its way upward.
An example is the Dome formed in crater left by 1980 eruption (explosion) of Mount St. Helens.

11. Lava Dome

12. Volcanoes
Tephra: pieces of rock and solidified lava that fall from the air. (all types of pyroclastic material)
Lahar: aa destructive mudflow on the slopes of a volcano. mixture of water , pyroclastic material, sand , and gravel capable of moving up to 100 km/hr (mudflow)

13. Volcanic Mud Flow (Lahar)

15. Wk. 2 Day 2 Before: Question of the Day During: Notes After: 3-2-1
What are the three type of volcanoes?
During: Notes
After: 3-2-1

16. Pyroclastic Material Ash, Lapilli, Lava Bombs
There are many kinds of pyroclastic material ejected during a volcanic eruption.
Ash
Ash is the most common pyroclastic rock material ejected during an eruption. Volcanic ash is so fine that it can be blown into the atmosphere and picked up by the jet stream where it can circle the Earth for several years.
Lapilli
Lapilli are pea-size to walnut-sized pieces of volcanic rock. All types of lava produces lapilli. Shield volcanoes, cinder cones, and composite volcanoes all produce lapilli
Lava bombs
Lava bombs are volcanic rocks larger than 64 mm in size. Lava bombs leave a volcano vent as glowing semi-molten rock fragments. While airborne lava bombs become streamlined forming aerodynamic shapes.

17. Violent volcanic eruptions
Lava blocks are often produced during violent volcanic eruptions when pieces of a volcano are blown away. The rock fragments are greater than 64 mm in size with no upward limit to their size.
Lava blocks
Lava blocks are large pieces of rock blown out of a volcano which have angular shapes and are solid. Some lava blocks are pieces of the volcano vent or sides of the volcano when it blows apart. The pieces can be as big as a small car. Lava blocks are the largest pieces of pyroclastic material ejected during a violent eruption.
Pumice
Pumice is light-colored igneous rock blown into the air in a semi-liquid state. The rock cools so fast it does not have time to crystallize. Gas bubbles inside the molten lava expands producing a rock that resembles a sponge.
Floating rocks
Pumice is often buoyant enough to float and has been known to float for thousands of miles after a major eruption. It is often found on the shores of volcanic islands thousands of miles from the eruption.

19. Pyroclastic Flows This eruption of Mt. Pinatubo caused
LOWER GLOBAL TEMPERATURES

20. Volcanoes
Igneous Rock – formed when magma hardens below the ground. Eventually, the process of erosion wears down rock at the surface, exposing features such as
Batholiths
Dikes
Sills

21. Igneous Rock Features
Batholiths – largest igneous rocks formed when magma cools underground.
Dike – magma that is squeezed into a generally VERTICAL crack that cuts across rock layers and hardens
Sill – magma that is squeezed into a HORIZONTAL crack between rock layers and hardens

22. Volcanoes
Volcanic Neck- the solid igneous core of a volcano left behind when a volcano stops erupting
Caldera – large opening formed when a volcano collapses

23. Caldera formation

25. Hot Spots Areas of volcanic activity in middle of a plate
Exact cause is unclear, possibly due to hot area of magma under the lithosphere
There are two equally valid hypotheses that might explain hot spots:
The plate could be moving over a stationary hot plume in the mantle, or the hot area causing the volcanic activity may be moving under a static, unmoving surface. At this point in our explorations, we are unable to confirm one or the other hypothesis--each is worthy of consideration.

26. Volcanic Results

29. Wk. 2 Day 3 Before: Question of the Day
What are pea-size to walnut-sized pieces of volcanic rock?
During: volcano in a cone Activity
After: Review

30. Before: Question of the Day What are Hot Spots? During: Review Mini- Q
Wk. 2 Day 4
Before: Question of the Day
What are Hot Spots?
During: Review
Mini- Q

31. Before: Question of the Day
Wk. 2 Day 5
Before: Question of the Day
What is a caldera?
During: Review
Mini Test

32. Week 3 December 14-18

33. Volcano Summative Assessment
Wk. 3 Day 1
Volcano
Summative Assessment

34. Wk. 3 Day 2-5
Exam Review and Exams