Volcano Lesson Notes PDF

VOLCANO OBJECTIVES At the end of this lesson, students should be able to: Identify the different types of volcanoes and their characteristic Differentiate types of volcanic eruptions. Recognize the active, dormant, and extinct volcanoes in the Philippines. Appreciate the ro...

VOLCANO OBJECTIVES At the end of this lesson, students should be able to: Identify the different types of volcanoes and their characteristic Differentiate types of volcanic eruptions. Recognize the active, dormant, and extinct volcanoes in the Philippines. Appreciate the role of volcanoes in shaping the Philippine landscape. 2  VOLCANO AND ITS PARTS TYPES OF VOLCANO What is a volcano and what How do you classify are its parts? volcanoes? TYPES OF VOLCANIC ERUPTION WHY DO VOLCANOES What are the different types ERUPT? of volcanic eruption? 1/2/2025 3 1/2/2025 4  MOUNT MAYON 1/2/2025 ALBAY, BICOL 5  TAAL VOLCANO BATANGAS PROVINCE 1/2/2025 6  MOUNT PINATUBO ZAMBALES 1/2/2025 7  WHAT IS A VOLCANO? A volcano is an opening in the Earth’s surface where molten rocks, smoke, gases, and ashes are erupted. 1/2/2025 8  WHAT ARE THE PARTS OF A VOLCANO? CRATER GAS & VOLCANIC ASH MAIN VENT PARASITIC CONE SIDE VENT gas and volcanic MAGMA ash CHAMBER 1/2/2025 9  Main Parts of a Volcano MAGMA CHAMBER – this is a chamber that has the magma that comes out of the volcano. MAIN VENT – this is the weak points of the earth’s crust where hot magma is able to rise from magma chamber and reach the surface. CRATER– mouth of the volcano that surrounds the main vent is the opening of the volcano. SIDE VENT– opening on the side of a volcano. PARASITIC CONE– is a cone-shape accumulation of organic material that is not part of the central vent of a volcano. GAS & VOLCANIC ASH– are materials that come out of the volcano. 1/2/2025 10  TYPES OF VOLCANO How do you classify volcanoes? ACCORDING TO THE FREQUENCY OF ERUPTION 1/2/2025 11  1/2/2025 12  According to Cone Shape Tall, symmetrical and with steep sides. Eruptions are dangerous and explosive, with many layers of lava and pyroclastic materials. Erupt hot gases, ash, lava, and pumice as well as stiff, slow-moving lava. Believed to have killed the most people because of their deadly nature and high numbers. 1/2/2025 13  Composite/Stratovolcano 1/2/2025 Designed by PoweredTemplate.com 13  Example: MOUNT FUJI 1/2/2025 JAPAN 14  Example: MOUNT MAYON 1/2/2025 PHILIPPINES 15  Example: MOUNT MERAPI 1/2/2025 INDONESIA 16  Circular or oval cones with almost vertical steep slope. Formed in a short period of time with size and shape like a hill. Erupt hot gases, ash, lava, and pumice as well as stiff, slow-moving lava. They are built from erupting lava that breaks into small pieces as it shoots into the air. As small pieces fall back to the ground, they cool and form cinders around the vent. 1/2/2025 18  Cinder Volcano 1/2/2025 18 1/2/2025 Example: Mt. Bulusan in Sorsogon 19  Example: LAVA BUTTE 1/2/2025 USA 20  Example: 1/2/2025 21  Not high and have a very broad shape with almost no slope. Shaped like a bowl or shield in the middle of the long gentle slope. Huge because of the ample supply of runny magma resulting to lava flow. Effusive or gentle eruption. 1/2/2025 22  Shield Volcano 1/2/2025 22  Example: MAUNA KEA 1/2/2025 HAWAII 23  Example: MAUNA LOA 1/2/2025 HAWAII 24  Example: MOUNT WRANGLER 1/2/2025 ALASKA 25  TYPES OF VOLCANIC ERUPTION IS A STEAM DRIVEN ERUPTION AS THE HOT ROCKS COME IN CONTACT WITH WATER. SHORT-LIVED, CHARACTERIZED BY ASH COLUMNS BUT MAY BE AN ONSET OF A LARGER ERUPTION. 1/2/2025 26  TAAL VOLCANO 1/2/2025 BATANGAS 27  2. PHREATOMAGMATIC ERUPTION IS A VIOLENT ERUPTION DUE TO THE CONTACT BETWEEN WATER AND MAGMA. RESULTS TO A LARGE COLUMN OF VERY FINE AND HIGH SPEED AND SIDEWAY EMISSION OF PYROCLASTIC MATERIALS CALLED BASE SURGES ARE OBSERVED. 1/2/2025 29  PHREATOMAGMATIC ERUPTION 1/2/2025 30  3. STROMBOLIAN ERUPTION IS CHARACTERIZED BY A WEAK TO VIOLENT ERUPTION CHARACTERIZED BY FOUNTAIN OF LAVA. AN EXAMPLE IS THE ERUPTION OF IZARU VOLCANO IN COSTA RICA. 1/2/2025 31  IZARU VOLCANO eruption 1/2/2025 31  4. VULCANIAN ERUPTION CHARACTERIZED BY TALL ERUPTION COLUMNS THAT REACH UP TO 20 KM HIGH WITH PYROCLASTIC FLOW AND ASHFALL TEPHRA. LIKE IN PARICUTIN VOLCANO IN MEXICO SMALL TO MODERATE EXPLOSION LASTING SECONDS TO MINUTES. 1/2/2025 32  paricutin VOLCANO eruption 1/2/2025 32  5. pliNIAN ERUPTION EXCESSIVELY EXPLOSIVE TYPE OF ERUPTION OF GAS AND PYROCLASTIC MATERIAL. HIGH RATE OF MAGMA DISCHARGE SUSTAINED FOR MINUTES TO HOURS AND CAUSED WIDE DISPERSION OF ASH. EXAMPLE IS THE ERUPTION OF PINATUBO VOLCANO IN ZAMBALES. 1/2/2025 33  MT. PINATUBO ERUPTION 1/2/2025 33  Tectonic Plates MASSIVE SLABS OF SOLID ROCK THAT GLIDES OVER THE EARTH’S MANTLE. 1/2/2025 34 1/2/2025 34 1/2/2025 34  Volcanic Eruption Magma inside the As the magma rises, bubbles volcano has high starts to fall as temperature. well. This magma has lower This adds pressure within the volcano density compared to forcing the molten the surrounding rocks rock into the air out causing it to rise. of crater. 1/2/2025 35 1/2/2025 35  Explosive volcanic eruptions generally occur when magma is thick and does not flow easily. It may block the vent of a volcano, allowing a build-up of gases. Gas pressures grows until the volcano erupts in an explosion. Ash and other particles from the eruption may form a mushroom cloud, like the cloud formed by a nuclear explosion. 1/2/2025 36 1/2/2025 36  Non-explosive volcanic eruptions generally occur when magma is thin and flow easily. Lava flows out of the volcano, rather than blocking the vent, and little or no gas forms inside the volcano. 1/2/2025 37 1/2/2025 37  Viscosity - is a measure of a fluid’s resistance to flow. MAGMA’S TEMPERATURE Magma’s viscosity decreases with temperature. The higher the temperature of magma, the less viscous it is. MAGMA’S CHEMICAL COMPOSITION Magma with high silica are more viscous than those with low silica content The magma that contains less silica is relatively fluid and travels far before solidifying. AMOUNT of Dissolved GASES Other factors being equal, gas dissolved in magma tends to increase its 1/2/2025 ability to flow. 38  Magma - molten rock material. EXPLOSIVE MAGMA High water content. High silica content. WHAT ERUPTS? Pyroclastic material - hot debris from the volcano FOUR TYPES OF LAVA 1. Blocky lava - cool stiff lava, doesn’t travel far 2. Pahoehoe - slow moving lava like dripping wax, forms glassy surface 3. A’a - Hawaiian for “Jagged lava” - formed jagged, underneath it continues to flow. 4. Pillow - forms underwater, rounded, bubble lumps 1/2/2025 38  BLOCKY LAVA 1/2/2025 38  PAHOEHOE LAVA 1/2/2025 38  A’a LAVA 1/2/2025 38  Pillow LAVA 1/2/2025 38  BIG QUESTION: WHY DOES THE PHILIPPINES HAS MANY VOLCANOES? 1/2/2025 38  RING OF FIRE A zone along the edge of Pacific Ocean that has many volcanoes. The horseshoe-shaped region around the Pacific Ocean that's known for its frequent earthquakes and volcanic eruptions 1/2/2025 38 1/2/2025 38  Assignment: ¼ sheet of paper Instructions: Write the correct answer on what is being asked. 1.What type of volcano has a broad base and gentle slopes formed by lava flows? 2.Which of the following is an example of a composite volcano in the Philippines, Mt. Mayon, Mt. Apo, Mt. Taal, or Mt.Banahaw? 3.What type of volcanic eruption produces lava that flows steadily and calmly? 4.Which term describes a volcano that has not erupted in thousands of years but may erupt again? 5.What is the smallest type of volcano, characterized by steep slopes and made from fragments of solidified lava? 6. What is the name of the molten rock that comes out of a volcano during an eruption? 7. Which type of volcano has steep sides and is made of layers of ash and lava- Composite, Shield, or Cinder? 8. Which of the following is NOT a product of a volcanic eruption - Ash, Gas, Lava, or Rain? 9. What do you call a volcano that will never erupt again- Active, Dormant, or Extinct? 10. Which Philippine volcano had a massive eruption in 1991?