Geological Hazards

Natural disaster is a natural phenomenon, which creates a disastrous situation, affects the normal activities of the population, threatens people’s life, destroys buildings, and results in death of human beings, animals, and destruction of property. The most common disasters of natural origin are the following:

- Geological hazards (landslides, avalanches and debris, earthquakes, volcanoes, etc.);
- Meteorological hazards (heavy rains, hurricanes, heavy snowfall, hailstorm, ice);
- Hydrological hazards (floods, increased groundwater, et al.);
- Natural fires of forest and grain areas;
- Mass infection and diseases of humans, animals, and plants.

Geological disasters are the most dangerous phenomena that are manifested primarily by earthquakes and volcanism. These calamities are caused by the eruption of magma from the depths of the Earth on its surface.

Earthquakes are the variations of the Earth's crust that arise in the result of explosion in the depths of the Earth, they break the layers of the crust causing volcanic activity. “Of all natural hazards, earthquakes release the most energy in the shortest possible time.”(Juan). Earthquake foci are located at a depth of 30-60 km, sometimes – 700 km. “The USGS estimates that several million earthquakes occur in the world each year. Many go undetected because they hit remote areas or have very small magnitudes.” (USGS). Depending on the cause and place of occurrence, the earthquakes are divided into tectonic, volcanic, and seaquakes. Earthquakes take over large areas and result in the destruction of buildings, emergence of massive fires and industrial accidents, flooding of towns and entire regions as well as poisoning with gases during volcanic eruptions. During earthquakes, many people get injured, loose their homes because of collapse or flushing of settlements with tsunami waves; in the end, they suffer from psychological traumas.

Volcano is a hole in the Earth's crust, through which the fiery mixture of gases, vapors, ashes, and half-molten rock (lava) is thrown on the surface with a great force. Particles of ash fall on the ground covering it with a thick layer and converting in light gray stone. Over millions of years, volcanic mountains have formed from the layers of lava. Often, they are quite high and shaped like a cone with a crater on the top. There are many volcanoes on the seabed. “Volcanism is associated with earthquake zones, being produced by the same fundamental forces.” (Moral del Roger). Losses from eruptions of volcano mud are quite significant including the destruction of buildings, settlements, etc. Active volcanoes emit mercury vapor, the content of which during the eruption increases in the air by 1-2 points of magnitude. This leads to the geochemical anomalies that are harmful for the human health.

Issues associated with the reduction and elimination of the results of disaster should be solved by public services. They have to protect the population from geological disasters, epidemics, and so on. Among the measures aimed at reducing the damage from the disaster, the preparation and training of the population, organization of rescue services, creation of infrastructure, evacuation of people from the areas of natural disasters are the most important. In the case of a large-scale disaster, the state may declare an emergency in certain areas.

Dealing with the consequences of any geological disaster consists in the following actions: informing the public services and population about the dangers of geological disasters; management and organization of rescue forces in the affected area. Reconnaissance and establishment of the degree and extent of damage, detection of the towns that may be affected by geological disasters and determination of the number of forces needed to be engaged for the rescue and other operations are the important steps in managing any natural disaster. The authorities should also provide medical aid for victims, evacuate them to hospitals and safe places, and ensure material support. Maintenance of public order in the affected area and organization of transportation support and other measures are aimed at preparing successful rescue operations.