On 7th, January 2025, a mid-intensity earthquake of around 7 scaled shook the Tibet and claimed 95 human lives and 130 are in a critical condition. These vibrations affected Nepal, India and Bangladesh with many people panicking and infrastructures being affected. This sad event has exposed that the fault line of the Himalaya region can shake at any point of time. But what caused this area becoming more sensitively to experience earthquake zone is:
Formation of the Himalayas
The spectacular Great Himalaya range, which comprises several of the world’s highest summits, started to rise about 50 million years ago when the Indian lithospheric plate began to converge with the Eurasian plate. This impact brought the folds of land and made our giant Himalaya range which we witness now. However this process is not yet complete and the India plate still slips northwards into the Eurasian plate at a pace that is estimated to be 40-50 mm per years.
Tectonic Plate Movements
Earthquakes are faults known as fractures that exist in the crust of the earth and result from movements occurring on tectonic plates. The Himalayan region is particularly seismically active because it sits at the boundary of two major tectonic plates: the Eurasian plate and the Indian plate. These plates are always moving, but they can only move sideways because the edges stick to one another because of friction. When the stress on the edge overcomes the friction an earthquake occurs where stored energy is released in waves in the form of tremors that move through the Earth’s surface.
Seismicity in the Himalayas
The Himalayas make one of the seismically most active areas of the world as the collision between the Indian and Eurasian plates continues. This collision leads to fairly constant levels of seismicity and fairly often there are earthquakes of different scale. The recent earthquake in Tibet is just one example of the region’s seismic risk.
Consequence of the Latest Earthquake
This earthquake whose magnitude measured around 7 on the Richter scale hit at the base of the mountains with a different depth cantering around the Nepalese region at a depth of 10 kilometres. The shaking was reported in some areas of northern India and Kathmandu in Nepal; people, buildings, and structures were shaking and left homes in panic. The Chinese government has mobilized 1500 local fire-fighters and rescuers, as well as 22000 disaster relief supplies.
Future Concerns
The recent earthquake has inspired people to question the proposed construction of a mega dam on the Tsangpo River in Tibet. This has made several countries such as India and Bangladesh in the downstream to object arguing that the project might lead to harm the environment, and the fault line. That is why seismically sensitive region becomes problematic when it comes to such large construction projects.
The part of Himalayas of the west forms one of the largest zones prone to earthquake ravages in the entire world. Since August this year, scientists have been warning that the larger region extending 2,500 km across the Hindu Kush to Arunachal Pradesh is ripe for an earthquake over 8. An incredible amount of energy resides along the fault zone and continues to accumulate owing to the unceasing movement of tectonic plates is potentially capable of being released only in the form of a great earthquake.
Why Himalayas experience Frequent Earthquakes?
The area of Himalayas is considered to be among the most vulnerable to earthquakes in the world. This frequent earth shaking is mainly caused by continuous interaction of the Indian tectonic plate with the Eurasian tectonic plate. Some 50 million years ago, the Indian plate started to move north wards towards Eurasian plate and in the subsequently formed mountains of Himalayas. Geologically, this process has persisted to this time and more vigorously, the Indian plate moves northward at the rate of 40-50 mm per year. Tectonic plates at this convergent boundary undergo a very great pressure and this leads to a very great friction at the floor of the movement and this makes stress to develop in the Earth’s crust. In turn, when this stress is released it leads to the creation of an earthquake.
The geographical area of the region is seismically active due to many faults and fractures in the earth’s crust of the area. These are the areas which provide a pathway for the ground to break and hence there is likelihood of an earthquake. Notably, the Main Himalayan Thrust (MHT) fault is a significant source of seismic activity in the region.
Measures to lessen the Effects of Earthquakes
As Himalayan region remains vulnerable to seismic activities here are recommend measures that need to be undertaken in order to address this issue:
Seismic-Resistant Infrastructure:
- Building Codes: It is crucial to maintain and extend proactively the physical code which is the building construction code pertaining to earthquakes. Both civil engineers and mechanical engineers should employ latest technologies and construction materials that help reduce seismic vulnerability of inhabitants in their buildings, bridges, and other structures.
- Retrofitting: Evaluations have also shown that it is possible to lower the building’s actual threat of collapsing during an earthquake by modifying the existing structures to fit today’s seismic requirements. This comprises of restoration of the pillar, the walls, and any other structural in the building.
Early Warning Systems:
- Detection and Alerts: It’s possible to prevent disasters resulting from quakes by having systems that can identify the occurrence of quakes and offer an alert. It is an ensemble of methods which aims at detecting motions in the ground and alert people of shaking within seconds to minutes ahead of the event to enable them to shield themselves.
- Education and Drills: Education campaigns and earthquake simulations can make the people understand how the disaster can further be handled. Instructing people to drop, cover, and hold on minimizes death and injuries in an earthquake.
Land-Use Planning:
- Risk Assessment: Using risk assessments to identify high-risk areas to avoid development of key infrastructure in the high-risk locations while increasing the possibility of their being able to develop and implement appropriate safeguards that can be included in land use planning effectively.
- Zoning Regulations: The guidelines may be to enact zoning codes that would prohibit activities in these areas considered as seismically high-risk in order to reduce the impact to these communities.
Disaster Preparedness and Response:
- Emergency Plans: Of equal importance is creating of the best practice plans of action which are relevant in emergency situations and should be revised from time to time. These plans should reflect how to manage evacuation; how to communicate and how to search and rescue during the incident.
- Community Involvement: Successful community inclusion in planning and executing the disaster preparedness would improve response to disasters. It can also be immensely helpful to train community members on first aid or search and rescue, or how to best respond in an emergency.
Research and Monitoring:
- Seismic Monitoring: Seismic stations should be installed to obtain further information of earthquake occurrence and to increase the efficiency of seismology. All the said information can be utilized in a more accurate prediction of risks and development of preparedness measures.
- Research Initiatives: Funding studies in areas of seismology, fault characteristics and earthquake hazards can contribute to the improvement of protective measures in future.
What is an Earthquake?
Natural calamity which is referred as an earthquake can be described as a natural occurrence that involves shaking of the earth surface. This shaking is due to energy that is set up in the Earth crust and due to movement of tectonic plates it releases this energy after some time. Quakes may also be considered as mild, moderate and great shaking where the latter is very destructive.
Why Do Earthquakes Happen?
Natural catastrophes especially earthquakes take place because of movement of the tectonic plates. Lithosphere of the Earth including the crust as well as the superior portion of the mantle is split into a number of larger and minor plates, which owe their movement on the asthenosphere, a semi-fluid layer. The tectonic plates are always in motion, although at a very slow rate because of the heat convection currents in the mantle.
When these plates meet they can either move apart from each other (Divergent Boundaries), slide past each other (Transform Boundaries) or actually move towards each other (Convergent Boundaries). These interactions cause stress on faults – which are cracks in the earth crust. It continues to accumulate with time and when stress reaches a level higher than the friction between the rocks, they may fail or slip. If this pressure is released suddenly, it forms energy that creates seismic movements as waves in the Earth’s surface and this we call an earthquake.
Types of Earthquakes
- Tectonic Earthquakes: Tectonic earthquakes are by far the most familiar type and originate from tectonic plates shiftage. They occur at all kinds of boundaries however are more related to the convergent and the Divergent boundaries.
- Volcanic Earthquakes: These earthquakes are presumably related with volcanic processes. These happen when hot molten materials reach the surface of earth cracking the overlying rock while producing earthquake vibrations. Volcanic earthquakes are associated with a volcano and may occur before an eruption takes place.
- Collapse Earthquakes: These are smaller quakes that happen over areas with caves or mines in the earth surface. Its fragile structures can bring about what is known as micro-earthquakes.
- Induced Earthquakes: Certain human activities include mining, reservoir induced seismicity will result from filling such large reservoirs, geothermal energy and hydraulic fracturing may cause earthquakes. These are relatively less energy generating than tectonic quakes but they can be very destructive.
How Are Earthquakes Measured?
Earthquakes are measured using two primary scales: the Richter scale and the moment magnitude scale abbreviated as Mw.
- Richter scale: Real time numbers are based on the Richter scale which was invented by Charles F. Richter in 1935 and relates the amount of energy released by an earthquake to the amplitude of seismic waves. A tenfold rise in wave amplitude and about a 31.6-fold increase in energy release is associated with each complete number increment on the logarithmic scale.
- Moment Magnitude Scale (Mw): The moment magnitude scale makes it feasible to quantify the entire energy produced by an earthquake. It considers the moment magnitude, which depends on the stiffness of the rocks and the typical amount of sliding in a fault location. Just like the Richter scale, the MMS is also a logarithmic scale, the moment magnitude scale is an expansion of the Richter scale. However, it gives a more integrated and complete magnitude determination particularly in the case of big quake.
Equipment called seismographs have been utilized for recording various kinds of seismic waves. These record equipment analyses the ground movements at different points to create seismograms that the seismologists may use to identify latitude, longitude, depth, and intensity of the quake.
It is natural disasters that happen due to motion of tectonic plates of the earth. Familiarity with causes of earthquakes, the classification of such movement, and the measurement units used is essential for evaluating seismic risks and reducing human losses. Seismic activities and monitoring technologies are still improving, contributing to better understanding and consequently to prediction and prevention of these phenomena.