The Ratu River Expedition: Earthquakes in Nepal was produced by the Earth Observatory of Singapore in collaboration with the Department of Mines and Geology, Nepal. The original idea was to produce a short science documentary that would be of interest to a general audience while also providing information about ground-breaking scientific research.
After several months of hard work in the field the Structural Geology team surveyed nine different rivers and collected terabytes of data. Judith Hubbard, Principal Investigator, explains: Now the fault, the main frontal thrust is exposed all the way here in the southern part of the Ratu River, and it’s exposed up here in a different strand to the West but the interaction between these two strands is unclear. We know from terrace data and from river cuts that both of these strands actually slipped, ruptured in the 1934 earthquake. But how that rupture transferred from one fault strand to the other fault strand is still unclear, and that’s something we are trying to get a handle on by looking at the subsurface data in that transition zone.
The Himalaya were created by the collision of the Indian tectonic plate with the Eurasian plate. These plates have slowly moved together over time over the last 50 million years. Sometimes they get stuck because of the high friction and they build up the stress slowly over time. Every few hundred years they slip, and an earthquake happens.
The new scientific discoveries at the Ratu River indicate that this area will continue to have significant earthquake activity for years to come. The Main Himalayan Thrust will continue to shift and break as the Indian plate continues to move against the Eurasian plate. It is impossible to predict exactly when new earthquakes will happen. But scientists can better anticipate future earthquakes by studying the relation between the deep movements in the fault and the displacements observed on the surface. Future loss of human life can be minimized by reinforcing new and existing buildings in Nepal to resist large earthquakes.