The document discusses volcanic eruptions, defining a volcano and explaining the process of eruptions caused by rising magma, which releases lava, ash, and gases. It highlights the importance of studying eruptions for understanding their environmental impact and land formation, and contrasts quiet and explosive eruptions. It also mentions notable eruptions, disaster preparedness, and the effects on local communities, emphasizing the challenges of controlling lava flow.

1. VOLCANIC
ERUPTIONS
: C A U S E S , EFFECTS, A N D P R O C E S S E S .
By Group
1

2. • What is a Volcano?
- A volcano is a mountain that forms a magma when its hot and
pushes through the surface. The
is magma comes out as lava, ash, and gases during an eruption.
• Why do we need to study the volcanic eruptions?
- It is important to study the causes and effects of volcanic eruptions
because they can be dangerous and can affect the environment.
studying them also helps us understand how the earth is formed and
how new land is created.
INTRODUCTION

3. HOW VOLCANIC
ERUPTIONS HAPPEN?
Volcanic eruptions happen when magma from deep inside the
Earth rises to the surface due to pressure buildup. The eruption
sends lava, ash, and gases into the air. As the lava cools, it turns
into solid rock, creating new land. Even though eruptions can be
dangerous, they help form new land, improve soil, and provide
energy.

4. MATERIALS RELEASED
DURING THE ERUPTION
Volcanic Ash: Fine particles of rock blasted during eruption.
Volcanic Bombs: Large, solid pieces of rock thrown out.
Volcanic Dust:Very tiny particles that spread far.
Lava: thick lava moves slowly and forms rocks.
Thin, hot lava flows quickly down the volcano's sides.

5. TYPES OF
VOLCANIC
ERUPTIONS
Quiet eruptions occur when lava flows gently and steadily,
often forming broad,
sloping volcanoes like shield volcanoes.
Explosive eruptions are powerful and violent,
releasing ash, rocks, and gases due to trapped pressure,
which is common in stratovolcanoes.

6. HOW CAN LAVA BE STOPPED?
It is extremely challanging to stop
the lava from flowing but we can
slow it down by building barriers
or redirecting the lava and cooling
the lava with large amount of
water. however, these methods
cannot stop the eruption itself

7. Mt. Pinatubo erupted in 1991, killing around 700 people.
It caused massive lahars (muddy flows) due to mixing of debris with
water, snow, and melted ice
Local Impact:
Widespread destruction in Porac, Pampanga and surrounding
areas. Many homes, bridges, and structures were destroyed.
MT PINATUBO ERUPTION (1991)

8. MT.MAYON ERUPTION (2014)
Eruption Details:
In 2014, Mayon erupted, but nobody died during the eruption,
even though it was considered to be deadlier than previous
eruptions.
Preparedness:
The successful disaster preparedness program of local agencies
and the cooperation of people within the volcano's vicinity
played a key role in preventing fatalities.

9. BEFORE THE ERUPTION:
Pressure forms in the lava chamber, gases escape, and the ground may slant
or crack
DURING THE ERUPTION:
Pressure is released as lava, ash, gases, and mudflows explosively come out.
AFTER THE ERUPTION:
Pressure stabilizes, and gases and ash can cause a global temperature drop,
with a caldera possibly forming.
STAGES OF A VOLCANIC ERUPTIONS

10. THANK
YOU
FOR Y O U R AT TE N T I O N
BY GROUP 1