In the YouTube video "Different Types of Volcanic Hazards | DRRR | SHS," the speaker discusses various volcanic hazards in the Philippines, focusing on Ta'al volcano and the negative impacts of volcanic eruptions, such as destruction of properties, injuries, and displacement of people. The speaker then explains the differences between effusive (quiet) and explosive (violent) eruptions and discusses several hazards arising from volcanic activity. Lava flows, which are stream-like flows of molten rock, can bury and burn everything in their path. Collapses of viscous lava domes can trigger pyroclastic flows, which are destructive and can only be mitigated through evacuation prior to eruptions. Ash fall or tephra fall can cause poor visibility, slippery roads, and damage to agricultural lands, industrial machines, and critical facilities. Pyroclastic flows and surges are turbulent masses of volcanic materials and hot gases that can destroy anything in their path. Lahars, or volcanic mudflows, can block tributaries, form lakes, and lead to long-term flooding problems in low-lying communities. Volcanic gases, including sulfur dioxide, carbon dioxide, and hydrogen sulfide, can lead to acid rain and harm people, animals, agriculture, and properties. Debris avalanches, or massive collapses of a volcano, can bury valleys and communities with debris. Ballistic projectiles, or volcanic materials ejected with force and trajectory, endanger life and property by the force of impact. The speaker also mentions tsunamis, which were discussed in a previous video.
00:00:00 In this section of the YouTube video titled "Different Types of Volcanic Hazards | DRRR | SHS," the speaker discusses various volcano-related hazards in the Philippines and explains the differences between them. The video begins with a discussion about volcanoes and the hazards they pose, with a focus on Ta'al volcano in the Philippines. The speaker identifies the negative impacts of volcanic eruptions, including destruction of properties, injuries, and displacement of people.
The speaker then goes on to discuss the two types of volcanic eruptions: effusive (quiet) and explosive (violent). Effusive eruptions occur when lava flows out of the volcano, while explosive eruptions occur when magma is blown to pieces. Volcanic hazards are phenomena arising from volcanic activity that pose potential threats to people or property within a given period of time.
The speaker then discusses the first volcanic phenomenon, which are lava flows. Lava flows are stream-like flows of molten rock erupted from a crater or fissure. When lava is gas-free or very viscous, it tends to extrude extremely slowly, forming lava domes. The negative impacts of lava flows include burying, crushing, covering, and burning everything in their path. Lavas can burn and melt areas they cover, and can also bury homes and agricultural areas under meters of lava.
00:05:00 In this section of the YouTube video titled "Different Types of Volcanic Hazards | DRRR | SHS," the speaker discusses various hazards associated with volcanic eruptions. One such hazard is the impact of lava flows, which can render areas useless by solidifying and blocking mobility and accessibility. Another hazard is the collapse of viscous lava domes, which can trigger dangerous pyroclastic flows. The speaker then moves on to ash fall or tephra fall, which are hazardous due to poor visibility, slippery roads, and damage to agricultural lands, industrial machines, and critical facilities. Pyroclastic flows and surges, which are turbulent masses of volcanic materials and hot gases, are potentially highly destructive and can destroy anything in their path. The only effective method of mitigating the risk of pyroclastic density currents is evacuation prior to eruptions. The speaker also mentions lahars, which are rapidly flowing thick mixtures of volcanic sediments and water, usually triggered by intense rainfall. Lahars can occur immediately after an eruption or become a long-term problem if there is a voluminous amount of pyroclastic materials erupted.
00:10:00 In this section of the YouTube video titled "Different Types of Volcanic Hazards | DRRR | SHS," the speaker discusses the negative impacts of volcanic hazards, specifically lahars, volcanic gases, debris avalanches, and ballistic projectiles. Lahars, or volcanic mudflows, can destroy villages and lives by direct impact, blocking tributaries and forming lakes, leading to long-term flooding problems in low-lying communities. Volcanic gases, including sulfur dioxide, carbon dioxide, and hydrogen sulfide, can lead to acid rain and harm people, animals, agriculture, and properties. Debris avalanches, or massive collapses of a volcano triggered by earthquakes or eruptions, can bury valleys and communities with debris and lead to negative impacts. Ballistic projectiles, or volcanic materials ejected with force and trajectory, endanger life and property by the force of impact, but only occur close to an eruption. The speaker also mentions tsunamis, which were discussed in a previous video.