Phreatomagmatic Eruption PDF

# Phreatomagmatic Eruption ## Presented by Group 4 ## What is a phreatomagmatic eruption? The word phreatomagmatic comes from the Greek word "phreat" or "phrear" meaning "water well" and magmatic from magma. A phreatomagmatic eruption is a violent volcanic eruption that occurs when magma comes i...

# Phreatomagmatic Eruption ## Presented by Group 4 ## What is a phreatomagmatic eruption? The word phreatomagmatic comes from the Greek word "phreat" or "phrear" meaning "water well" and magmatic from magma. A phreatomagmatic eruption is a violent volcanic eruption that occurs when magma comes into contact with water. This water can be groundwater, surface water, or water-rich rock. As a result, a large column of very fine ash and high-speed and side-ways emission of pyroclastics called base surges are observed. ## Types of Phreatomagmatic Eruptions - Submarine Phreatomagmatic Eruptions - Occur underwater. - Subaerial Phreatomagmatic Eruptions. - Occur on land. - Phreatomagmatic Explosions - Small-scale, localized events. ## How do phreatomagmatic eruptions occur? Phreatomagmatic eruptions happen when hot, rising magma directly interacts with underground or shallow surface water. Water will flash into steam, expand, and cause an explosion. ## Pyroclastic Pyroclastic is an adjective that describes something related to or made up of small pieces of rock that come from a volcano. The term can also refer to the rocks themselves, which are called pyroclastic rocks. ## Pyroclastic Materials - Also called tephra, these materials are formed when magma cools during a volcanic eruption. They can range in size from ash to boulders and can be found in many parts of the world. ## Pyroclastic Flows - These are extremely destructive and deadly mixtures of gas, ash, and rock fragments that move away from a volcano at high speeds. They can reach temperatures of over 1,500°F and can cause serious injuries and death to people and animals. ## Pyroclastic rocks - These are rocks like pumice that are ejected from a volcano as broken, solid fragments. ## Hazard Phreatomagmatic eruptions can be extremely dangerous, causing burns, asphyxiation, and burial under hot volcanic material. ### Example: Phreatomagmatic Eruption in Taal Volcano - **Date:** Dec. 3, 2024 - **Cause:** The eruption was likely caused by water suddenly coming into contact with a small amount of shallow magma beneath the volcano's main crater ## Hazards associated with Phreatomagmatic Eruptions | Hazard | Description | | ---------------------------- | ----------------------------------------------------------------------------------------------------------------------------- | | Tsunamis | Submarine eruptions can generate devastating tsunamis. | | Pyroclastic Flows | Fast-moving, hot ash clouds | | Ashfall | Widespread ash deposition. | | Lahars | Mudflows formed by ash and water. |