Earth and Space

  • Lesson 1: Earthquakes and Faults

  • A fault is a fracture or zone of weakness in the Earth's crust where movement has occurred or may occur again. [1] Faults are found at the edges of tectonic plates. [1]

  • The hanging wall is the block of rock above a fault, and the footwall is the block below. [2]

  • The different types of faults include normal, reverse, thrust, strike-slip, and oblique faults. [2] Each type is characterized by the direction of movement along the fault plane.

  • Active faults have shown evidence of movement within the last 10,000 years, while inactive faults have not. [3] Active faults are considered geological hazards. [3]

  • The focus of an earthquake is the point inside the Earth where the earthquake originates. [4]

  • The epicenter is the point on the Earth's surface directly above the focus. [4]

  • Earthquake magnitude is a measure of the energy released at the focus. [4]

  • Earthquake intensity is a measure of the effects of an earthquake on people and structures. [4]

  • The Philippines has several major fault lines, including the Guinayangan Fault, Masbate Fault, Vigan-Aggao Fault, and Marikina Valley Fault System. [5]

  • Earthquakes are classified as shallow, intermediate, or deep based on their focal depth. [6]

  • Benioff zones are inclined zones of seismic activity that occur at plate boundaries where trenches exist. [6]

  • Aftershocks are smaller earthquakes that follow a larger earthquake (mainshock) in the same area. [6]

  • Foreshocks are earthquakes that occur before a larger earthquake in the same location. [6]

  • Earthquake swarms are sequences of seismic events within a relatively short period, with no clear mainshock. [6]

  • Earthquake hazards include ground rupture, ground shaking, liquefaction, structural damage, and soil breaking/erosion. [7]

  • Earthquake sub-hazards include fire, floods, and tsunamis. [7]

  • It is important to be prepared for earthquakes by having an emergency kit, first-aid training, securing heavy objects, anchoring furniture, and learning earthquake plans. [7, 8]

  • During an earthquake, follow the "Duck, Cover, and Hold" protocol. [8]

  • After an earthquake, check for injuries, damage, and updates, and stay away from damaged buildings. [9]

  • Lesson 2: Seismic Waves

  • Seismic waves are vibrations in the Earth caused by the release of energy during an earthquake. [9]

  • Body waves travel below the Earth's surface and include P-waves (compressional) and S-waves (transverse). [10]

  • Surface waves travel along the Earth's surface and are more destructive than body waves. [10] Surface waves include Love waves (horizontal motion) and Rayleigh waves (rolling motion). [10]

  • Seismic waves slow down in the Earth's core because it is liquid, and they speed up in the upper mantle because it is denser rock. [10]

  • Lesson 3: Tsunamis

  • A tsunami is a series of large ocean waves caused by an underwater earthquake, landslide, or volcanic eruption. [11]

  • Tsunamis are usually generated by reverse/thrust faults. [11]

  • Notable tsunamis include the Indian Ocean Earthquake and Tsunami (2004), the Japan Earthquake and Tsunami (2011), and the Moro Gulf Earthquake and Tsunami (1976). [12]

  • Lesson 4: Typhoons

  • A typhoon is a tropical storm that occurs in the Western Pacific Ocean. [12]

  • Tropical cyclones are named differently depending on their location. [12]

  • Typhoons typically occur from late June to December. [12]

  • The Coriolis Effect deflects typhoon winds counterclockwise in the Northern Hemisphere. [12]

  • Tropical cyclones are classified by wind speed, ranging from tropical depressions to super typhoons. [13]

  • Typhoons form over warm ocean waters and are fueled by warm, moist air. [13]

  • Lesson 4.1: Effects of Landmasses and Bodies of Water on Typhoons

  • Typhoons weaken over landmasses due to a lack of warm, moist air. [14]

  • Typhoons may regain strength if they move back over warm water. [14]

  • The eye of a typhoon is the calmest area, surrounded by the eyewall with the most intense winds. [15]

  • A front is a boundary between two different types of air masses. [15]

  • PAGASA names typhoons alphabetically using the Filipino alphabet. [14]

  • The Rain Shadow Effect causes one side of a mountain range to receive less precipitation than the other. [16] The windward side faces the prevailing wind and receives more rain, while the leeward side is drier. [16]

  • The Sierra Madre Mountain range in the Philippines weakens typhoons by blocking moist air and causing them to lose energy. [17]

  • Lesson 5: Asteroids, Comets, Meteoroids

  • Near-Earth Objects (NEOs) include asteroids, comets, and meteoroids. [18]

  • Asteroids are rocky fragments that orbit the Sun, mainly found in the asteroid belt between Mars and Jupiter. [18]

  • Asteroids are classified by composition (C-type, S-type, M-type) and location (main belt, near-Earth, Trojans). [18, 19]

  • Comets are icy bodies that release gas and dust when they approach the Sun. [19] They are classified by their orbital period (short-period or long-period). [20]

  • Meteoroids are small rocks and boulders in space. [20] When a meteoroid enters the Earth's atmosphere and burns up, it is called a meteor. [21] If a meteor survives and hits the ground, it is called a meteorite. [21]