A 5.4 magnitude earthquake hit the northern part of India on Tuesday, June 13, 2023, at around 1:30 pm (Indian Time). The quake was felt in several states, including Punjab, Haryana, Delhi NCR, Jammu, and Kashmir, and parts of Pakistan and Afghanistan. However, no serious damage or casualties were reported.
The Location and Depth of the Quake
The quake occurred about 70 km southeast of Fayzabad, a city in northeastern Afghanistan, near the border with Tajikistan. The quake had a depth of about 223 km, which reduced its impact on the surface, according to the National Seismic Monitoring Centre in Islamabad.
The National Center for Seismology (NCS) in India also confirmed the quake and its location, saying it occurred at 1:30 pm at “Lat: 36.56 & Long: 71.13, Depth: 220 Km” in Afghanistan.
The Effect and Reaction of the Quake
The quake was strong enough to shake buildings and windows in some areas, causing panic among people who ran out of their homes and offices. However, there were no immediate reports of any significant damage or injuries.
The authorities in India and Pakistan issued alerts and advised people to stay calm and follow safety precautions. They also said they were monitoring the situation and ready to provide any assistance if needed.
Some people took to social media to share their experiences and express their relief that the quake was not severe. Some also posted videos and photos of the tremors and their aftermath.
The Richter Scale and Magnitude of the Quake
The Richter scale is a measure of the strength of earthquakes, developed by American seismologists Charles F. Richter and Beno Gutenberg in 1935. It is based on the logarithm of the amplitude (height) of the largest seismic wave recorded by a seismograph.
The Richter scale is logarithmic, which means that each whole number increase in magnitude represents a tenfold increase in measured amplitude. For example, a magnitude 5 quake is 10 times stronger than a magnitude 4 quake, and 100 times stronger than a magnitude 3 quake.
The Richter scale also corresponds to the amount of energy released by an earthquake. Each whole number increase in magnitude corresponds to an increase of about 31.6 times the amount of energy released. For example, a magnitude 5 quake releases about 31.6 times more energy than a magnitude 4 quake, and about 1,000 times more energy than a magnitude 3 quake.
The Richter scale was originally devised for moderate earthquakes (magnitude 3 to magnitude 7) occurring in southern California. However, it can be applied to other regions and larger earthquakes using different seismographs and adjustments.
The Richter scale is still widely used by the media and the public to describe earthquake magnitudes, but it has some limitations and drawbacks. For instance, it does not account for the duration or frequency of seismic waves, or the type and size of fault rupture that causes an earthquake.
Therefore, seismologists now use other scales, such as the moment magnitude scale (Mw), which is based on the seismic moment (a measure of the size and strength of fault rupture) of an earthquake. The moment magnitude scale is more accurate and consistent for large earthquakes than the Richter scale.
The moment magnitude scale also uses a logarithmic scale similar to the Richter scale, so that their numeric values are roughly comparable for most earthquakes. For example, the moment magnitude of the 2004 Indian Ocean earthquake that triggered a devastating tsunami was estimated at Mw 9.1-9.3, while its Richter magnitude was estimated at ML 9.1-9.3.
However, there are some differences between the two scales for very large or very small earthquakes. For example, the moment magnitude of the 1960 Valdivia earthquake in Chile, the largest earthquake ever recorded, was estimated at Mw 9.4-9.6, while its Richter magnitude was estimated at ML 9.5.
Similarly, the moment magnitude of some very small earthquakes may be negative, while their Richter magnitude may be positive. For example, an earthquake that occurred near Los Angeles in 1992 had a moment magnitude of Mw -0.1, while its Richter magnitude was ML 0.7.
The Frequency and Causes of Earthquakes in the Region
The northern part of India and its neighboring countries are prone to frequent and sometimes powerful earthquakes, due to their location in a seismically active zone. The region lies at the convergence of three major tectonic plates: the Indian Plate, the Eurasian Plate, and the Arabian Plate.
The Indian Plate is moving northward at a rate of about 5 cm per year, colliding with the Eurasian Plate, which is moving southward at a slower rate. This collision creates immense pressure and stress along the boundary, resulting in the formation of the Himalayan mountain range and the Tibetan Plateau.
The collision also causes the Indian Plate to subduct (slide under) the Eurasian Plate along a fault line called the Main Himalayan Thrust (MHT). This subduction generates earthquakes of various magnitudes and depths, ranging from shallow to intermediate to deep.
The Arabian Plate is also moving northward, colliding with the Eurasian Plate along a fault line called the Chaman Fault. This collision causes the Arabian Plate to subduct under the Eurasian Plate along a fault line called the Makran Trench. This subduction also generates earthquakes of various magnitudes and depths, mostly shallow to intermediate.
The region also experiences earthquakes due to other factors, such as volcanic activity, landslides, and human-induced activities, such as mining, dam construction, and nuclear testing.
Some of the most devastating earthquakes that have occurred in the region include:
- The 2005 Kashmir earthquake (Mw 7.6), which killed over 80,000 people and injured over 100,000 people in Pakistan-administered Kashmir, India-administered Jammu and Kashmir, and Afghanistan.
- The 2001 Gujarat earthquake (Mw 7.7), which killed over 20,000 people and injured over 160,000 people in Gujarat, India.
- The 1999 Chamoli earthquake (Mw 6.8), which killed over 100 people and injured over 1,000 people in Uttarakhand, India.
- The 1993 Latur earthquake (Mw 6.2), which killed over 10,000 people and injured over 30,000 people in Maharashtra, India.
- The 1935 Quetta earthquake (Mw 7.7), which killed over 30,000 people and injured over 60,000 people in Balochistan, Pakistan.
The Preparedness and Mitigation Measures for Earthquakes in the Region
The governments and agencies of India and its neighboring countries have taken various steps to improve their preparedness and mitigation measures for earthquakes in the region. Some of these steps include:
- Establishing and upgrading seismic networks and early warning systems to monitor and report earthquake activity and provide timely alerts to the public and authorities.
- Developing and enforcing building codes and standards to ensure that structures are earthquake-resistant and can withstand strong shaking.
- Conducting seismic hazard and risk assessments to identify vulnerable areas and populations and prioritize resources for disaster management.
- Educating and training the public and stakeholders on earthquake safety and response measures, such as drop, cover, and hold on; evacuation; first aid; fire safety; etc.
- Organizing drills and exercises to test and improve the readiness and coordination of emergency services and relief agencies.
- Strengthening the capacity and resilience of communities to cope with and recover from earthquake impacts, such as providing financial assistance, psychological support, reconstruction assistance, etc.
Despite these efforts, there are still many challenges and gaps that need to be addressed to enhance the earthquake preparedness and mitigation measures in the region. Some of these challenges include:
- Lack of adequate funding and resources for seismic monitoring and disaster management.
- Lack of awareness and compliance among the public and stakeholders on earthquake safety and response measures.
- Lack of coordination and communication among different agencies and sectors involved in earthquake management.
- Lack of reliable data and information on seismic hazards and risks in some areas.
- Lack of effective mechanisms for accountability and transparency in disaster governance.
Therefore, it is essential that all stakeholders work together to overcome these challenges and improve their earthquake preparedness and mitigation measures in the region. This will help reduce the loss of lives and property and enhance the resilience of communities in the face of future earthquakes.
