• A magnitude-6.0 earthquake hit the mountainous region in eastern Afghanistan bordering Pakistan on August 31.

• The earthquake killed more than 1,400 people and injured over 3,300, Taliban authorities said, making it one of the deadliest in decades to hit the impoverished country.

• Emergency workers struggled to reach remote villages devastated by the earthquake.

• The vast majority of the casualties were in Kunar province, with a dozen dead and hundreds hurt in nearby Nangarhar and Laghman provinces.

• In the first critical 24 hours after the earthquake hit, access was “very limited”, owing to landslides and rockfalls triggered by the tremors. Some roads were already blocked by previous rockslides caused by recent heavy rainfall.

• India delivered 21 tonnes of relief materials to Afghanistan as part of its assistance to earthquake-hit people of that country.

• Afghanistan is prone to deadly earthquakes, particularly in the Hindu Kush mountain range, where the Indian and Eurasian tectonic plates meet. 

Some terms related to earthquake

Earthquake: An earthquake is a sudden, rapid shaking of the ground caused by the shifting of rocks deep underneath the Earth’s surface. Earthquakes can cause fires, tsunamis, landslides or avalanches. Earthquakes are classified as, Slight (M<5.0), Moderate (5.0<M<6.9) and Great (M>7.0) depending upon the magnitude on the Richter scale. An earthquake having a magnitude, M<2.0 is termed as a microearthquake. 

Seismograph: A seismograph, or seismometer, is an instrument used to detect and record earthquakes. Generally, it consists of a mass attached to a fixed base. During an earthquake, the base moves and the mass does not. The motion of the base with respect to the mass is commonly transformed into an electrical voltage. The electrical voltage is recorded on paper, magnetic tape, or another recording medium. This record is proportional to the motion of the seismometer mass relative to the earth, but it can be mathematically converted to a record of the absolute motion of the ground. Seismograph generally refers to the seismometer and its recording device as a single unit.

Richter scale: The Richter magnitude scale was developed in 1935 by Charles F. Richter of the California Institute of Technology as a mathematical device to compare the size of earthquakes. The magnitude of an earthquake is determined from the logarithm of the amplitude of waves recorded by seismographs. Adjustments are included for the variation in the distance between the various seismographs and the epicenter of the earthquakes. On the Richter Scale, magnitude is expressed in whole numbers and decimal fractions. 

Epicenter: It is the point on the surface of the Earth, vertically above the place of origin (hypocenter or focus) of an earthquake.

Aftershock: An earthquake that follows a large magnitude earthquake called, “main shock” and originates in or around the rupture zone of the main shock. Generally, major earthquakes are followed by a number of aftershocks, which show a decreasing trend in magnitude and frequency with time.