An earthquake results from a sudden energy release in the earth’s crust that causes a seismic wave which in turn causes shaking of the ground and leads to devastating occurrences.
Areas with greatest concentration of earthquakes:
Although limits do not exist to the probable magnitude of earthquakes, the largest in historic times as noted by: Debora, 2012 was slightly above a magnitude of 9.0 which occurred in Japan in 2011. Areas with greatest concentration of earthquakes in the US include: Alaska, California, Hawaii, Nevada, Washington, Idaho, Wyoming, Montana, Utah and Oregon
Reasons for greatest concentration of earthquakes in these areas:
Aftershocks: areas which have previously experienced earthquakes are more prone to earthquakes because the ground here is still active than areas which have not experienced earthquakes before. These areas are believed to have experienced earthquakes before
Volcanic activity: when a volcanic eruption occurs the hot lava from the earth’s surface is forced out as magma and this causes a disturbance in the crustal rocks and this disturbance may result in an earthquake. These areas are areas that have experienced volcanic eruptions and earthquakes.
Anthropogenic activities: these are human induced activities such as mining and quarrying. During mining activities or quarrying activities, rock are drilled using heavy machinery which disrupts the position of crustal rocks which leads to vibration and hence movements of these rocks. This continuous vibration and movement of these rocks leads to release of energy and this can lead to an earthquake occurrence.
Earthquake storm: they occur just like aftershocks, just that they occur after several years apart, unlike aftershocks which can occur even after a previous earthquake. In an earthquake storm, a small earthquake leads to a larger earthquake which occurs along the same fault plate as the stress from one earthquake is passed along the fault system.
The location with the largest most recent earthquake on the map is South West of Yonakuni, Japan, which had a magnitude of 5.9 and a depth of 63km. the ecological and biological impacts to this region are so many, some of which affect the people around seriously.
Some Human impacts also come as a result of earthquakes. The people around get injured and there’s also loss of life of the people around and property damage which in most cases is not covered by insurance companies or is charged high premiums. This can also lead to lack of basic needs as the normal life and operations of the residence is interfered with.
Floods can also occur as a result of earthquakes. They are secondary effects, like for instance when an earthquake and damage a dam, landslips are caused which cause these dams to collapse and cause floods. This can lead to loss of life and spread of diseases.
Tsunamis result from earthquakes of magnitude of over 7.5 or more, and travel many kilometers across the open ocean causing the shores to be weak after the earthquakes generated on them. These make shores vulnerable to landslides and general destruction of property.
Fire is also an effect of earthquake. This can occur when hot molten rocks are forced out into the earth surface, and upon collision with objects on the surface can trigger fire. Earthquakes can also lead to fires which can damage electrical power or gas lines. For example, an earthquake caused fire in San Francisco in 1906.
References
Deborah R. (2012). The Earthquake observers Disaster Science from Lisbon to Richter. University of Chicago press
Donald H, David H ,(2009). Earthquakes and their causes. Natural Hazards and Disasters. 2nd ed, Brooks/Cole learning
