Causes and Efeects of Earthquakes

CAUSES AND EFFECTS OF EARTHQUAKES, TSUNAMI AND CYCLONES

EARTHQUAKES

What are Earthquakes?

← An earthquake (also known as a quake, tremor or temblor) is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time. Earthquakes are measured with a seismometer; a device which also records is known as a seismograph. The moment magnitude (or the related and mostly obsolete Richter magnitude) of an earthquake is conventionally reported, with magnitude 3 or lower earthquakes being mostly imperceptible and magnitude 7 causing serious damage over large areas. Intensity of shaking is measured on the modified Mercalli scale.

← Usually associated with faulting or breaking of rocks

← Continuing adjustment of position results in aftershocks

Causes of earthquakes :

← Eruption of volcanoes

← Tectonic activity

← disturbance in the movement of plates

← under crust waves

← cracks in the plates.

Effects/impacts of earthquakes:

← Shaking and ground rupture

← Landslides and avalanches

← Fires

← Soil liquefaction

← Tsunami

← Floods

← Tidal forces

← Human impacts :

HUMAN IMPACTS:

Earthquakes may lead to disease, lack of basic necessities, loss of life, higher insurance premiums, general property damage, road and bridge damage, and collapse or destabilization (potentially leading to future collapse) of buildings. Earthquakes can also precede volcanic eruptions, which cause further problems; for example, substantial crop damage

EARTHQUAKE SAFETY MEASURES

DURING AN EARTHQUAKE:

• Stay away from windows, bookcases, file cabinets, heavy mirrors, and other heavy objects that could fall

• Duck under a desk or study table

• Watch for falling plaster or