How are the two phenomena connected, Prof. M. I. Bhat locates the link between scientific research and inter-faith animosity.

Historical records about inter-faith relationships are hardly an uncontestable fact among different communities in any part of the world. Grudge of one or the other sort are held by one community against the other for some happening (or un-happening) in the past. Unfortunately there is no way to revisit the past and observe such happenings as impartial observers for their validity.

One grudge held by Kashmiri Hindu community against the local Muslim community is that a former Muslim ruler, Sikandar (1398-1413 A.D.) destroyed Hindu temples. The history goes that the temples were destroyed by filling them with wooden logs that were put on fire. Muslims are skeptical to accept this view and point to another historical account which attributes temple defilement and destruction to a Hindu king, Harsha (1089-1101 AD).

Fortunately for both the communities, developments in earthquake studies may help to shed some light on the issue. It might be hard to believe that a science that deals with a natural hazard as destructive as an earthquake could help in resolving such a community issue. But then that is the beauty of science. If rightly used it always has only good for the humanity.

Lack of time-series data on earthquakes world-wide has forced earthquake scientists to resort to looking for information about past earthquakes from different sources, like historical records (historical seismology), sediments, etc (paleoseismology) in order to create a database for earthquake prediction. This is precisely similar to what climatologists, faced with lack of time-series climate data, have also resorted to in terms of historical climatology and paleoclimatology to overcome difficulties in climate prediction. A further development in this direction in the field of earthquake science is the study of archeological masonry structures known to have suffered earthquake damage to seek information on past earthquakes (about peak ground motion, frequency and duration, which, in turn, allow inferences about likely earthquake intensity and magnitude).This has given birth to the nascent but fast developing scientific discipline known as Archeoseismology. There are quite a number of case studies, especially from Middle East, where concepts and methodologies of archeoseismology have been applied on archeological masonry ruins to decipher information about ancient earthquakes.

As a part of our study of the looming earthquake threat to the Kashmir Valley, we too face the problem of scanty information on past earthquakes in this region. Despite the fact that Kashmir has written history that goes back in time to about 5,000 years (Pandit Kalhan’s Rajatarangini, 1149-50 AD), yet the first reasonably clear mention of an earthquake is seen for 844 AD earthquake. For the next 300 years, there is reference to only one earthquake (1123 AD) and again for another about four centuries one earthquake is mentioned in the chronicles. The question that strikes the mind is: How is it likely that a region seismically as vulnerable as Kashmir and literally littered with evidence for active tectonics could have experienced just three (or four, if we include Sandimatnagar earthquake with a wide time frame of 2082–2041 BC) earthquakes over almost 3,500 years? The rising mountains surrounding the Kashmir Valley, the elevated Karewas (wŭdurs in local parlance) and the courses of big and small streams attest to the fact that the Kashmir Valley is deforming and must have seen, and will see, innumerable big and small earthquakes. Though mention of earthquake occurrence increases from 16th century, the information is skimpy.

So with the failure on historical front, we turned to archeoseismology. Our first obvious choice was the most visible archeological masonry sites – the Hindu temples. There are quite a number of big and small temples built of massive, close-fitting dressed, stone blocks (with dimensions up to 4.3 x 3.6 x 2.8 m for floor blocks and up to 2 x 2 x 1.5 m for roof blocks) spread across Kashmir. Beginning with Shiva Temple at Pandretahn, we surveyed and made observation at ten temples that include temples at Avantipura, Payar, Martand, Naranag, Parihanspura, Patan, and Buniyar. All of them were constructed during 750-950 AD. Most of them are in ruins; some partly repaired.

As a pilot study we initially focused on the nearest and relatively well documented Pandrethan temple for our observations.  A British geologist, R. D. Oldham, who photographed the temple in 1887, attributed the damage to the temple to the 30th May 1885 Kashmir earthquake. However, there is a photograph by another British, John Burke, nine years older (1868 AD) to that of Oldham’s that also shows many of the same roof blocks in the temple displaced from their original positions, thereby discounting Oldham’s attribution. For a casual observer the photographs do not resolve the vandalism issue. But for an expert both the photographs contain a wealth of information, a lot of which has survived repairs and could be verified from the site itself. Other than the visible loss of summit pyramid capstone blocks, the photographs show vertical cracks in the temple structure and clear differential horizontal displacement of stone blocks. Also, several stone blocks at higher levels remain misaligned. In terms of their position, the displaced blocks are at higher levels (in the roof part) and not at lower levels near the pediment. The differential displacement (offset) increases sequentially upward – a clear sign of shaking suffered by the temple.

Fire may cause cracks in a stone structure but it can not cause horizontal displacement of heavy stone blocks. Moreover, it would not have caused dismantling of pyramid capstones leaving decorated stone ceiling under those capstones unscathed and intact. Nor would vandalism produce sequentially upward increasing displacement. Equally, no amount of human force could have shaken such a strong and heavy structure. Rather, it is a known fact that during an earthquake a building shakes (due to surface wave phenomenon) more, therefore experiences greater horizontal displacement and consequently greater damage, at higher levels than at base.

To sum up, the loss of pyramid capstones, horizontal displacement of still existing displaced stone blocks, and those that may have been repositioned in recent repairs, and vertical cracks together are the characteristic features that are known from other earthquake-damaged archeological masonry buildings. The temple now has a tilt of 5°, which could either be earthquake-induced or, more likely, due to differential setting of the structure since it is constructed over unconsolidated sediments.

With these observations we visited the other nine listed temple sites. To our surprise, the Pandrethan temple is not the only temple that bears such unmistakable and undisputed stamp of earthquake-induced damage. Each of the other nine temples has lost pyramid capstones and suffered horizontal displacement and some have also suffered separation of stone blocks. The magnitude of the visible destruction correlates with the size of temple complex.

With such strong evidence for earthquake-induced damage to these temples, the inescapable conclusion is that whatever temples Sikander or Harsha or both may have defiled and destroyed, the ten temples that we studied are unlikely to be among them.

The next step in our study is to model the likely ground shaking that could have caused the observed structural damage. This involves numerically recreating block-by-block picture of the preserved displaced blocks and restoring them within the original frame which will then be subject to simulated ground shaking until documented structural failures are mimicked. We hope to achieve important insights about the past earthquake history of Kashmir. As a spin off of these studies, I hope science helps lessen the grudge between Hindus and Muslims of Kashmir.

Lastupdate on : Wed, 12 Aug 2009 21:30:00 Makkah time
Lastupdate on : Wed, 12 Aug 2009 18:30:00 GMT
Lastupdate on : Thu, 13 Aug 2009 00:00:00 IST