In the first part of the October seminar Michael Willis looked at a range of archaeological and geological evidence pointing to seismic and climatic events at a number of sites in India. One example supporting a significant climatic event during the Paramāra dynasty comes from the Dandak cave in Chhattisgarh, in the Malwa region. The growth of stalagmites here points to a drought around 1051. Following research by Sinha et al. into indications of monsoon rainfall given by stalagmite growth in peninsular India that can be accurate to within a decade, the same methodology was applied at Dandak cave. The evidence from the stalagmites corroborates information given in the Nagpur inscription (c.1070-93) from the reign of king Udayāditya which reads “when the realm was overrun by floods…”
Another piece of evidence from the region comes from the Kakanmaṭh Śiva temple built by Kirtirāja c.1015-35 CE. Much of the temple is now ruined and a Sanskrit inscription from c.1393-94 CE says that the temple had been renovated around that time, though no indication is given of when the damage had occurred. Taken with the geological indicators from Dandak, and the archaeological evidence from Old Māṇḍū, there is a good body of evidence to suggest that an earthquake and its subsequent impact on the flow of waters from the river Betwā to the perennial valleys around Māṇḍū was responsible for the relocation of the capital city at some point within a decade or so of the mid-11thcentury CE.
The second part of the seminar focussed on the devasting earthquakes to hit Nepal in 2015 and archaeological findings that have resulted from post-disaster excavations. The excavations were undertaken at Hanuman Dhoka, Patan and Bhaktapur by the Nepali government’s Department of Archaeology and Durham University.
One of the most significant cultural heritage losses was the destruction of the Kasthamandap. Excavations revealed that the original mud mortar and brick core foundations of the temple were in fact highly resilient and had withstood numerous seismic events over the centuries. A dating technique known as Optically Stimulated Luminescence puts the laying of these foundations at 700 CE, some 500 years earlier than previously thought. The cause of Kasthamandap’s collapse seems in fact to have been the result of modern conservation to the building’s structure. One of the significant causal factors was a saddlestone at the northeast corner which had been tiled over during the mid-late twentieth century.
In addition to the important archaeological evidence elucidated by post-disaster excavation for the history of monuments in Kathmandu – such as the antiquity of the foundations and the fact that they appear to have been constructed as a nine-cell mandala – work like that undertaken by the UNESCO/Durham University team is also critical to improving the structural resilience of historic sites against future disasters. Given that the original mud mortar and brick building techniques had given the structure foundations which withstood many earthquakes over the centuries, it is now clear that modern conservation and restoration efforts should learn from these. While disaster relief and humanitarian efforts always take precedence in the face of such natural catastrophes, there is much to learn from archaeology in how to mitigate against the worst of damage in rebuilding.
In the final part of the seminar Janice Stargardt talked about the work she and colleagues have done in establishing the role that climatic change had played in the decline of Angkor in Cambodia and Sri Ksetra in Burma.
Central to understanding the archaeological sites and the role of climatic events over time is the development of the water management systems used to irrigate land. At Angkor, for instance, aerial photography and remote sensing reveal how phases 2 and 3 of the sites had an expanding hydraulic system used to irrigate the land. This can be considered indicative of the wealth and prosperity of the Khmer Empire at this time. By the 14thcentury however, decline was underway. Dendrology has been used to confirm that increasingly weak monsoons were experienced during this time, and this would have had a serious impact on the irrigation system which was dependent on single-season monsoons. In addition to this and its consequences for supporting the population, the weak eastern wall was a poor barrier for the reservoir and hydraulic system, but ultimately even more consequentially for military defence.