DRRR

DISASTER ➢ Impacts on people, infrastructure and the environments. ➢ Actual event that can endanger many people.

COMPONENTS ➢ Typically calculated by considering

HAZARDS ➢ Potential causing harm. ➢ Thefreuency and severity of hazardous events.

EXPOSURE ➢ The extent to which people, property, and infrastructure, are exposed to these hazards.

VULNERABILITY ➢ The suspectability of exposed elements to the hazards, including their ability to cope with or recover from the hazards.

EARTHQUAKE ➢ It is the result of sudden movement along faults within the earth. ➢ Usually caused when the underground rock suddenly breaks and there is rapd motion along the fault.

SEISMIC WAVES ➢ Created by the abrupt movement of elements within the earth, such as fault slips during an earthquake. 4 TYPES 1. Primary (P-wave)- body waves 2. Secondary (S-wave)- body waves they can travel inside the earth at high speeds. 3. Rayleigh- surface waves 4. LoveWaves-surface waves they can travel at slower speeds close to the earth’s surface.

INTENSITY ➢ Strength of an earthquake perceived and felt by people in a certain locality. ➢ Generally higher near the epicenter.

MAGNITUDE ➢ Energy released by an earthquake at the focus. It is calculated from earthquakes recorded by an instrument called seismograph. THE DEADLIEST EARTHQUAKE: 1. Tangshan, China (1976): July 28, 1976 Magnitude: estimated as 7.5 Death Toll: 242,000 people 2. Shaanxi, China (1556): January 23, 1556 Magnitude: estimated 8.0 Death Toll: 830,000 people 3. Indian Ocean Tsunami (2004): December 26, 2004 Magnitude: 9.1-9.3 Death Toll: 230,000-280,000 people 4. Haiti (2010): January 12, 2010 Magnitude: 7.0 Death Toll: 160,000-230,000 people 5. Kanto, Japan (1923): September 1, 1923 Magnitude: 7.9 Death Toll: 140,000 people ➢ The "W" in the context of earthquake magnitudes is part of the notation and represents "Moment Magnitude," a modern standard for measuring seismic events. (Mw8.3)

ADDITIONAL INFORMATION ➢ Chile (1960) Biggest earthquake ever recorded (9.5) at a subduction zone where the pacific plate dives under the South American plate. ➢ Philippines (1980) Largest historical earthquake with a magnitude of 8.3 at Celebes Sea

WARNING SIGNS THAT INDICATE IMPENDING EARTHQUAKES ➢ 1. Unusual animal behavior: Animals may act strangely or become agitated before an earthquake. 2. Small tremors or foreshocks: These are smaller earthquakes that can occur before a larger earthquake. 3. Ground uplift or subsidence: Changes in the ground level can be a sign of stress building up along fault lines. 4. Changes in groundwater levels: Sudden changes in well water levels can be caused by shifts in the Earth's crust. 5. Radon gas emissions: Increased levels of radon gas can be released from the ground before an earthquake

LAVA FLOWS ➢ Molten rock that erupts from a volcano and flows down its sides. ➢ Often slow-moving but can be destructive to anything in their path, including buildings and infrastructure.

PYROCLASTIC FLOWS ➢ Oneof themostdeadly volcanic phenomena. ➢ An extremely hazardous, fast-moving currents of hot gas, ash, and volcanic rocks that race down the sides of a volcano at high speeds. ➢ Can reach temperatures of over 1,000°C (1,800°F) and can travel at speeds of up to 700 km/h (435 mph).

ASHFALL ➢ Consists of tiny fragments of rock, minerals, and volcanic glass blasted into the air during an eruption. ➢ blanket large areas, damaging crops, contaminating water supplies, and causing respiratory problems.

VOLCANIC GASSES ➢ Emit various gasses, including water vapor, carbon dioxide, sulfur dioxide, and hydrogen sulfide. ➢ Can be toxic or corrosive and can lead to health issues. It’s high concentrations of gasses can also contribute to acid rain, which can harm the environment.

LAHARS ➢ Volcanic mudflows or debris flows that occur when volcanic ash and debris mix with water from rain, melting snow, or ice.

VOLCANIC LANDSLIDES ➢ Large-scale landslides or avalanches of rock and soil can be triggered by volcanic eruptions or the destabilization of volcanic slopes.

VOLCANIC TSUNAMIS ➢ Eruptions or landslides into bodies of water can displace large volumes of water, generating tsunamis.

TEPHRA FALLOUT ➢ All volcanic materials ejected during an eruption, including ash, pumice, and volcanic rock. ➢ Affect areas far from the eruption site, impacting air travel.

VARIOUS INDICATORS TO PREDICT VOLCANIC ERUPTIONS 1. Seismic Activity- Increased earthquake activity. 2. Ground Deformation- As magma rises, it can cause the ground around the volcano to deform. 3. Gas Emissions- Changes in volcanic gas emissions can indicate an impending eruption. 4. Thermal Changes- Rising magma can heat the surface of the volcano, causing changes in thermal readings. 5. Hydrothermal Activities- Increased activity in hot springs, geysers, or fumaroles (venting gases) around a volcano can be a sign of rising magma. 6. Changes in Volcano’s Behavior- unusual noises, such as rumbling or booming sounds, can be associated with volcanic activity. 7. Magnetic and Gravity Changes 8. Historical Patterns- Examining past eruptions and patterns of volcanic activity can provide context for current signs. 9. Volcanic Deformation Mapping 10. Water Chemistry Change- Involcanic lakes and streams, changes in the chemistry of the water, such as increased acidity or the presence of new chemical elements, can indicate rising magma.