Tsunami Lesson Plan PDF

Tsunami Tsunami – is a series of sea waves generated by various geological processes and commonly generated by under-the- sea earthquakes and whose heights could be greater than 5 meters.  Example of recent tsunami events in the Philippines are the August 1976 Moro Gulf Earthquake and Tsunami...

Tsunami Tsunami – is a series of sea waves generated by various geological processes and commonly generated by under-the- sea earthquakes and whose heights could be greater than 5 meters.  Example of recent tsunami events in the Philippines are the August 1976 Moro Gulf Earthquake and Tsunami and the November 1994 Oriental Mindoro Earthquake and Tsunami.  Tsunami vs. Storm Surge A Tsunami is a Japanese word meaning “harbor waves”. Tsunami is commonly generated by distances associated with earthquakes occurring below or near the ocean floor. It occurs when earthquake is shallow- seated and strong enough to displace parts of the seabed and disturb the mass of water over it. The increase in wave heights associated with or during typhoons (where there are strong winds) or tropical cyclones is called a “storm surge”  How are tsunamis generated?  Tsunamis are commonly generated in subduction zones under the ocean where two plates collide, with one plate (A) moving down under the other (B)  How are tsunamis generated?  When plates get stuck, the overriding plate (B) gets distorted  How are tsunamis generated?  Stuck area ruptures triggering an earthquake pushing up the ocean floor and seawater above. This starts the tsunami which moves in opposite directions.  Two types of Tsunami The coastal areas in the Philippine especially those facing the Pacific Ocean, West Philippine Sea, Sulu Sea and Celebes Sea can be affected by tsunamis that may be generated by local earthquakes  1. Local tsunamis are confined to coasts within a hundred kilometers from the source. It is usually generated by earthquakes and landslide or pyroclastic flow. It can reach the shoreline within 2 to 5 minutes. When plates get stuck, the overriding plate (B) gets distorted. Stuck area ruptures triggering an earthquake pushing up the ocean floor and seawater above. This starts the tsunami which moves in opposite directions.  Two types of Tsunami  2. Far field or distant tsunamis can travel from 1 to 24 hours before reaching the coast of the nearby countries. These tsunamis mainly coming from the countries bordering Pacific Ocean like Chile, Alaska in USA and Japan. Pacific Tsunami Warning Center (PTWC) and Northwest Pacific Tsunami Advisory Center (NWPTAC) are the responsible agencies that closely monitor Pacific- wide tsunami event and send tsunami Phivolcs.dost.gov.ph warning to the countries around the Pacific Ocean  PHILIPPINES TSUNAMI INFORMATION DOST-PHILVOLCS. Tsunami Prone Map shows coastal areas in the Philippines that can be affected by tsunamis generated by under-the-sea earthquakes or submarine landslide. Tsunami waves generated by earthquakes from other countries may affect the country as well  NATURAL SIGNS OF AN IMPENDING TSUNAMI  1. Feel an earthquake If the ground shakes under your feet in a coastal region, a tsunami may have been caused by strong undersea earthquake. However, you may not feel an earthquake if the event is far away. If the ground shakes under your feet in a coastal region, a tsunami may have been caused by strong undersea earthquake. However, you may not feel an earthquake if the event is far away  NATURAL SIGNS OF AN IMPENDING TSUNAMI  2. See ocean water disappear from the beach, bay, or river Before a tsunami arrives, water may recede from the shoreline before returning as a fast-moving wall of water. If you notice the water is declining, tell your family and friends and prepare to move inland or to higher ground  NATURAL SIGNS OF AN IMPENDING TSUNAMI  3. Hear an unusual roaring sound If you hear a loud roar approaching (a bit like a passenger jet or a train). tell as many people as possible. It could be a tsunami approaching. PHIVOLCS issues the Tsunami Warning Sign to warn citizen of Impending Tsunami PHIVOLCS issues the Tsunami Warning Sign to warn citizen of Impending Tsunami PHIVOLCS issues the Tsunami Warning Sign to warn citizen of Impending Tsunami