EARTHQUAKES
– GEOGRAPHY
News: Why are earthquakes frequent in
Afghanistan? | Explained
What's
in the news?
●
An earthquake of magnitude 6.3 struck
Western Afghanistan on October 15, barely a few days after multiple earthquakes
of similar strength killed at least a thousand people in the Herat province.
●
Multiple earthquakes have destroyed entire
villages in the country.
Key
takeaways:
●
Afghanistan is located over multiple fault
lines in an area where tectonic plates collide often, leading to significant
tectonic activity.
Earthquake:
●
An earthquake in simple words is the shaking of the earth. It is a natural
event. It is caused due to release of
energy, which generates waves that travel in all directions.
●
The vibrations
called seismic waves are generated from earthquakes that travel through the
Earth and are recorded on instruments called seismographs.
●
The location below the earth’s surface
where the earthquake starts is called the hypocenter,
and the location directly above it on
the surface of the earth is called the epicenter.
Earthquake
prone areas:
●
National Geophysical Laboratory,
Geological Survey of India has divided India into the following five earthquake
zones:
○
Very high damage risk zone
○
High damage risk zone
○
Moderate damage risk zone
○
Low damage risk zone
○
Very low damage risk zone
Causes of earthquake:
Natural
Causes:
●
Volcanic eruption
●
Faulting and folding
●
Upwarping and down warping
●
Gaseous expansion and contraction inside
the earth.
●
Plate Movement
●
Landslides
Man-made/Anthropogenic
Reasons:
●
Deep underground mining
●
Blasting of rock by dynamites for
construction purposes.
●
Deep underground tunnel
●
Nuclear explosion
●
Reservoir Induced Seismicity (RIS)
Hydrostatic pressure of man-made water bodies like reservoirs and lakes.
Consequences
of earthquakes:
1.
Damage to life:
●
Around 2300 people died in India due to
the earthquake.
2. Landslides creation:
●
Tremors especially in mountain areas can
cause slope instability and slope failure leading to debris down the slope
causing landslides.
3. Tsunami:
●
Tsunamis are the waves produced due to
disruption of the ocean basin and displacement of the huge volume of water.
Seismic waves of an earthquake can displace sea floor and generate high sea
waves as Tsunamis.
●
Eg.
2004 Indian Ocean tsunami.
4. Floods:
●
The earthquake can lead to devastating
disturbances to dams, reservoirs and can cause flash floods.
●
Landslides and Avalanches which may block
the river course, leading to floods.
5. Damage to property:
●
The upheaval caused by an earthquake does
huge damage to the property. Especially in a developed area of high population
density, the damage to the property is huge.
Government
measures:
1.
Earthquake mapping:
●
Earthquake prone zones were identified and
mapped according to their proneness to the earthquake threat.
2. National Disaster Management Authority:
●
It was established to effectively make
disaster management and mitigation plans.
●
It also cooperates with states to
effectively manage disasters.
3. The National Center for Seismology:
●
An office of the Ministry of Earth
Sciences. It submits earthquake surveillance and hazard reports to governmental
agencies.
●
It includes three divisions: Earthquake
Monitoring & Services, Earthquake Hazard & Risk Assessment, Geophysical
Observation System.
4. National Earthquake Risk Mitigation Project (NERMP):
●
Strengthening the structural and
non-structural dimensions of earthquake mitigation efforts.
●
reducing the vulnerability in the
high-risk districts.
●
Necessary risk mitigation measures are put
in place in the highly seismic zones.
WAY
FORWARD:
1. The NDMA guidelines on earthquakes must be
implemented in letter and spirit.
2. A special earthquake management department must be created in very
high and high-risk seismic zones.
3. The traditional Khasi model of houses must
be promoted in the hilly region.
4. Providing tax incentives to people who build
earthquake resistant buildings.
5. A single point of
contact for various divisions of response for better coordination must be
developed.
6. Local population training and capacity building must be
done.
7. An effective way to do
that would be the empowerment of panchayats and municipal corporations in
earthquake management and response.