A lot has been reported about the 7.8 magnitude earthquake that shook up Nepal on 25th April, 2015. The devastation was severe throughout. Many heritage sites and structures were flattened. Despite this cruel dance of nature, the age old Pashupatinath still stands strong on the banks of river Bagmati. We here at Honeyguide Apps have tried to answer this burning question amongst many, how did Pashupatinath survive the earthquake?
Background/ History of Pashupatinath Temple
One of the most sacred and worshipped Hindu temple of Nepal, Pashupatinath’s exact date of construction is unknown but the earliest evidence of the temple’s existence dates back to 400 A.D. However, the present main temple was built at the end of the 17th century to replace the previous one destroyed by termites. Pashupatinath in literal sense means “Lord of all animals”. Few would disagree that Pashupatinath, in its silver and gold attire, is perhaps the most majestic temples of Nepal. With its heavily gilded gold and copper roofs, silver doors and exquisite wood carvings, Pashupatinath is one of the 7 world heritage sites of Nepal listed by UNESCO.
Numerous legends surround the Pashupatinath temple and its beginning. The Cow legend is perhaps the most famous one. It is believed that Shiva once visited earth in the form of an antelope and roamed around in a forest near Bagmati. Later caught by the gods, Shiva was asked to return to its duty. Shiva refused and thus force had to be used. In this conflict the antelope (disguised Shiva) lost one of its horns and later the very horn was started to be worshipped as a Lingam. Overtime this lingam was buried and lost. Centuries later, on the very spot where the lingam was buried, came a cow to offer its milk to it every day. A bewildered cowherd who watched this happening in great awe finally gathered some courage to dig the location. This was when the Shiva Linga was found and devotees started worshipping the linga once again.
Since we are talking Pashupatinath here, there will always be some religious beliefs attached to it. Its survival through the devastating earthquake also has garnered some interesting theories that Hindu devotees have thrown in. People are starting to claim that the sole reason of the still standing Pashupatinath is the divine power Shiva possesses.
Some religious groups are claiming that while constructing ancient temples “Vaasu Shastra” was given special attention to and temples were only built in those places that were not prone to natural calamities. Furthermore, they also claim that the mantras recited in the Pashupatinath temple helped escape its doom.
Most Hindus are also relating this ‘miracle’ with the ‘Kedarnath miracle’ of India. In 16th June, 2013, a powerful Uttarkhand flood swept away all of the vicinity except a Shiva Temple called Kedarnath. Many believed Shiva’s divine powers protected the temple from its doom, but in fact a news agency investigated that it was a huge stone that got stationed at a distance of few feet on the backside of the temple that prevented the flood from entering the temple. Similarly, there must be a more logical explanation as to why the Pashupatinath could withstand such a powerful earthquake.
The most relevant reason as to why the Pashupatinath still stands today boils down to its architectural build. The pagoda design, used in many Nepalese temples also adorns the Pashupatinath. This centuries old design could be the most important reason behind the Pashupatinath’s strong build. Let’s talk science:
Pagoda’s basic design is large roofs at the bottom, slightly smaller roofs at the top as the height and roofs increase. This build means that the weight is lighter at the top and heavier at the bottom; most structures that easily topple off have heavy roofs at the top.
In an earthquake, tremors that run through the ground have high frequency. But the pagoda design causes the structure to sway at a rate slower than the movement of ground. This swaying movement cancels out the vibrations from the ground. Sounds fascinating isn’t it? Here’s some more interesting facts, the different storeys of pagoda don’t lean on the same direction during an earthquake. Some sway to the left and some to the right, all the while maintaining balance and keeping the center of gravity almost constant. If all the storeys of pagoda lean at the same direction then the center of gravity would shift and the structure would collapse. This theory can be applied to the two tiered Pashupatinath as well. The first storey sways one direction and the second storey sways the opposite direction, therefore keeping the balance. By the way, 5 tiered pagoda styled Nyatapole Temple of Bhaktapur also stands strong today.
Here is a short clip that shows what an amazing structure the pagoda is:
Having said this, one could argue that the pagoda styled temples in Kathmandu Durbar Square got flattened by the same earthquake. This basically boils down to the building materials used in the structure’s construction, the date of its construction, its location and the soil underneath and the amount of wear and tear in the structure, all of which we will discuss later.
Another plus point in the construction of Pashupatinath is that its frame is made out of timber. Timber, even today, is a major part of earthquake resistant designs. The sole reason being, timbers are more flexible than concretes. It is already proven in an experiment that timber pillars can be slightly bent and be brought back to its original form. This could very well have added to the resilience of the temple. Another unintentional decision to not use nails in the construction of Pashupatinath probably made it more earthquake resistant. Nails were considered inauspicious and thought to invite bad omen in ancient times and so wooden wedges were used to connect any two parts. This led the interlocking system of pillars to be more flexible. During an earthquake, flexibility plays a vital role in a structure withstanding the shake. The builders of Pashupatinath definitely have some bragging rights!
Control factors of earthquake
The factors that either weaken or strengthen the earthquake waves and hence its strength is also important to determine before making any conclusions on why some structures fell and some survived. This is precisely why some modern buildings topple off in an earthquake while some older buildings manage to survive the same earthquake. The control factors that might be relevant with the still standing Pashupatinath are Path effect and Site effect.
In explaining path effect the following questions should be answered:
Which route did waves produced by the earthquake take before reaching its target? Did it travel through rocks or soft soil? Did it weaken the force of the earthquake or strengthen it?
And in explaining site effect the following questions should be answered:
In which topography is the structure in question situated? Is it situated at the top of a hill or at the base? What’s the soil underneath the structure like?
Also, there is something known as resonance effect in determining whether a building survives an earthquake or not. Every building has a natural frequency determined by its mass and stiffness. It is particularly dangerous if the seismic waves of earthquake happen to match the natural frequency of a building. When these two factors match the building in question will swing more violently than the earthquake itself. For e.g: In the Mexico City earthquake (8.0 magnitude) of 1985 most 6-15 storey buildings were flattened. Most shorter buildings survived which makes us believe that shorter buildings are better, but surprisingly buildings taller than 15 storeys also managed to survive the earthquake. What actually happened was that the frequency of earthquake’s seismic waves happened to match the natural frequency of the medium sized buildings, thus, causing the buildings to oscillate more violently than others. The learnings from the Mexico City earthquake can also be used to explain how Pashupatinath was able to survive the earthquake.
Staying in the peripheral of the topic, when asked about how Pashupatinath temple survived the big earthquake, Dr. Subodh Dhakal (Environmental Geologist and Geological Engineer) gave the following reasons via email:
1. The temple itself is not very tall, therefore low frequency waves that arrived in Kathmandu could not produce resonance effect as the natural frequency of short Pashupatinath Temple did not match the wave frequency of the earthquake.
2. The temple is not in elevated areas like that of Swayambhunath temple and also not in mountain crest where the waves can easily amplify.
3. Most importantly, the thickness of lake sediment in Pashupatinath temple is less, meaning that the bedrock is nearer to the surface as compared to other places which can play important role in reducing wave amplification.
4. The water table in this area might be low (We do not have exact data but our instinct says so) that prevent it from liquefaction.
Renovation works/ wear and tear
Although the existence of the temple dates back to 400 A.D, there are information that mention renovation works being carried out in the 17th century, which makes it younger compared to other centuries old temples. But perhaps a more scientific reason that explains lesser wear and tear of the temple as compared to other ancient structures is it's copper and golden roofs. The bottom roof is wide enough to cover the base and the structures considered to be important in an engineering point of view. A wide enough roof prevents rain and sunlight from making direct impact on wooden structures of the temple frame. Therefore, minimizing the wear and tear of the temple over the years.
In a country where Hinduism is the major religion, the strong and majestic Pashupatinath that survived the great earthquake not only this time around but also the great earthquake of 1934 signifies hope and strength to many. In fact there were people, interviewed by various news agencies that said they rushed to Pashupatinath after the April 25 earthquake because they thought the place ‘felt’ safe. On the other hand, there are many experts who would no doubt agree that it is not the sturdiest nor religious but the smartest building that survives an earthquake. Be it the scientific reasons behind its survival or the various religious beliefs, the fact remains that The Pashupatinath Temple indeed survived the great earthquake of 2015.