NATURAL HAZARD OR DISASTERS
Geological hazards are natural events or processes that originate from geological processes, mainly related to the Earth’s crust and its dynamic movements. These hazards can pose significant risks to human populations, infrastructure, and the environment. Some of the major geological hazards include:
- Earthquakes: Sudden shaking of the Earth’s surface caused by the release of energy along faults or tectonic plate boundaries. Earthquakes can result in ground rupture, landslides, and tsunamis, and their intensity is measured using the Richter scale or moment magnitude scale (Mw).
- Volcanic Eruptions: Explosive release of magma, gases, and volcanic ash from a volcano. Volcanic hazards include lava flows, pyroclastic flows (hot ash and gas clouds), volcanic ashfall, and volcanic gases. The severity of volcanic eruptions is categorized using the Volcanic Explosivity Index (VEI).
- Landslides: The sudden or gradual movement of soil, rock, and debris down a slope. Landslides can be triggered by heavy rainfall, earthquakes, volcanic activity, or human activities like deforestation or construction.
- Tsunamis: Large ocean waves generated by underwater earthquakes, volcanic eruptions, or landslides. When these waves reach shallow coastal areas, they can become much taller and cause devastating inundation.
- Subsidence and Sinkholes: Ground settling or collapse due to the removal of underground resources like water or minerals, or dissolution of limestone, leading to the formation of sinkholes.
- Rockfalls and Rockslides: Rapid downslope movement of individual rocks or large rock masses along steep slopes.
- Ground Subsidence: Gradual sinking or settling of the Earth’s surface due to various factors, such as mining activities, groundwater extraction, or natural compaction of sediments.
- Geomagnetic Storms: Disturbances in Earth’s magnetic field caused by solar activity, resulting in auroras and potential disruptions to power grids and communication systems.
- Geothermal Hazards: Eruptions of hot water, steam, and gases from geothermal systems that can lead to localized hazards in volcanic areas.
These geological hazards can have severe impacts on communities, causing loss of life, destruction of infrastructure, and economic losses. Preparedness, monitoring, early warning systems, and land-use planning are crucial for reducing the vulnerability of populations to geological hazards and improving overall disaster resilience.