Seismology, Seismic Waves, Seismograph:

Seismology is the science, which deals with all the topics related to seismic waves. The seismic waves are the pulses of energy generated by earthquakes, which can travel through all parts of the earth. These waves can be measured and recorded by an instrument called Seismograph. A seismograph consists of a pendulum with a fixed …

Measurement of Earthquakes

Measuring of an Earthquake: Generally, earthquakes occur at depths of lesser than 100 kilometers under the ground. The earthquakes are frequently noted by the instruments like seismography on daily basis. The location of the earthquakes are also determined by the seismographs. The point at which an earthquake is noted is known as the focus-point or …

Types of Earthquake waves

An earthquake produces four types of waves: (1). P-Waves (Primary Waves), (2). S-Waves (Secondary Waves), (3). L-Waves (Surface Waves), and (4). Rayleigh Waves: The tectonic movement releases a huge amount of energy, which is known as Seismic energy. Seismic energy express itself in the form of seismic waves. These seismic waves are known as earthquakes. …

Changes brought about by the earthquakes?

The earthquakes cause major changes in the crust and on the surface of the Earth. Important changes are as given below: (1). Expansion of Earth’s Crust (2). Contraction of Earth (3). Disturbance of drainage system (4). Mud Volcanoes (5). Cultural Landscape (6). Landsliding (7). Fire (8). Liquefaction, Subsidence, and Related Effects (9). Tsunamis (1). Expansion …

Causes of Earthquakes

An earthquake is a natural phenomenon, which has many causes behind it. Some of these are natural while others are man-made. Among these causes, the most important are as follow; (1). Tectonic Movement causes Earthquakes: Earth’s crust is divided into large segments (fragments) separated along ridges. These segments are called plates (Lithospheric Plates). The term …

What is mid-oceanic ridge (MOR)?

A mid-ocean ridge (MOR) is a seafloor mountain system formed by plate tectonics. It typically has a depth of ~ 2,600 meters (8,500 ft) and rises about two kilometers above the deepest portion of an ocean basin. This feature is where seafloor spreading takes place along a divergent plate boundary. In the middle of the ocean, there …

Earthquake Zones

Major Earthquake zones of the world include countries located on the Asian coast of the Pacific, the eastern coast of the Pacific covering the west coast of North America, and Latin America. Detail of the major zones is as under: The heaviest concentration of earthquakes is along the circum-pacific belt. It includes countries of Japan, …

Magnitude of Earthquakes

The intensity of an earthquake is assessed on the Rickter Scale, which was developed by geophysicist Charles Richter in 1935. This scale assigns a number to an earthquake based on the severity of the ground motion It ranges from 0 to 8+. It is logarithmic so that an earthquake with a magnitude 4 causes 10 …

What is an Earthquake?

An Earthquake may be defined as the shaking and trembling of the Earth’s surface caused by sudden releases of stress with the crust of Earth. Thus an earthquake releases the energy that has been gradually stored through the stress of increasing deformation of rocks. The released energy takes the form of seismic waves that radiate …

Volcanic Production/ Lava Composition

Volcanic eruptions produce many products out of which the following are very important; (1). Tuff: Rocks comprising of fine ash. (2). Agglomerates: Rocks consisting of pieces larger than 20 mm. (3). Volcanic Bombs: Rock pieces with a diameter of more than 32 mm. (4). Cinders: Fragments with diameter between 4 mm -32 mm. These are …