Earthquake

Earthquake: A Natural Disaster That Can Strike Anytime

Natural disasters can happen anywhere and anytime, and earthquakes are one of them. They are caused by sudden movements in the Earth's crust, which can result in shaking and vibrations on the surface. Earthquakes can be extremely dangerous and can cause significant damage to buildings and infrastructure, resulting in loss of life and property. In this article, we will explore the science behind earthquakes, their effects on the environment and society, and the measures that can be taken to mitigate their impact.

Understanding Earthquakes

Earthquakes are the result of tectonic movements within the Earth's crust. The Earth's crust is composed of several tectonic plates, which move and interact with each other. When these plates collide or move apart, it can result in the release of energy in the form of seismic waves. These waves can travel through the Earth's surface and cause shaking and vibrations.

The magnitude of an earthquake is measured using the Richter scale, which ranges from 1 to 10. A magnitude of 1 is barely perceptible, while a magnitude of 10 is extremely rare and can cause massive damage. Earthquakes with a magnitude of 7 or above are considered major earthquakes and can cause significant damage.

Effects of Earthquakes

Earthquakes can cause several types of damage, including structural damage to buildings and infrastructure, landslides, and tsunamis. The shaking and vibrations caused by earthquakes can cause buildings to collapse or suffer significant damage, resulting in loss of life and property.

Landslides can also be triggered by earthquakes, particularly in areas with steep terrain. These landslides can cause significant damage to roads and buildings, and can also block waterways, resulting in flooding and other environmental issues.

Tsunamis can also be caused by earthquakes that occur under the ocean. These waves can travel across vast distances and can cause significant damage to coastal regions. The damage caused by tsunamis can be severe and can result in loss of life and property.

Earthquake Hazards Mitigation

Here on the Big Island, we feel small earthquakes on a regular basis, and magma movement underground that precedes eruptive activity produces low-level tremor.

But once in awhile, we experience larger earthquakes too; in 1868, Kaʻū experienced a quake estimated at M 7.9 that knocked down every wall and building in the district, and took the lives of 81 people. These large earthquakes originate deep within or below the island, in areas where the rock itself is structurally weak.

Compared with other natural hazards, earthquakes are unique, because there is no warning. For all other natural disasters, you have a few minutes to a few days of advance notice that the tsunami, lava flow, or hurricane is on its way. But there is no warning for earthquakes. They can happen at any time. That means you have to be prepared at all times, because you never know when the next one is coming.

Natural occurrence

Wherever there is sufficient stored elastic strain energy to propel fracture propagation along a fault plane, earthquakes occur. If there are no irregularities or asperities along the fault surface that increase the frictional resistance, the sides of the fault will only move past one another smoothly and aseismically. Stick-slip behavior is caused by these asperities, which are present on the majority of fault surfaces. The volume surrounding the fault surface experiences an increase in stress and, as a result, stored strain energy once the fault has locked due to the continued relative motion of the plates. This go on until the pressure has risen adequately to get through the sharpness, out of nowhere permitting sliding over the locked part of the shortcoming, delivering the put away energy.[1] This energy is delivered as a mix of transmitted versatile strain seismic waves,[2] frictional warming of the shortcoming surface, and breaking of the stone, hence causing a quake. The elastic-rebound theory describes this gradual buildup of strain and stress, occasionally punctuated by sudden earthquake failure. Seismic energy accounts for only about 10% of an earthquake's total energy, according to estimates. The majority of the earthquake's energy is converted into heat produced by friction or used to propel earthquake fracture growth. As a result, earthquakes lower the Earth's elastic potential energy that is available and raise its temperature, but these changes are insignificant in comparison to the conductive and convective flow of heat out of the Earth's deep interior[3].