India is moving northwards at a rate of around 5cm a year and pushing up the Himalayan massif. In theory, there should be a knock-on effect: Tibet should be moving eastwards at the rate of 2-3cm a year. But no such thing is happening, according to Comet, the centre for the observation and modelling of earthquakes and tectonics at Oxford University.
Tim Wright and colleagues used a technique called interferometric synthetic aperture radar (Insar), which can measure Earth movements to an accuracy of millimetres. They gathered Insar data gathered by European remote sensing satellites between 1992 and 1999, and measured surface motion across a 500km stretch of western Tibet. There was almost no movement along either of two faults.
“Our finding is that plate tectonics do not work in Tibet,” Wright said. “It seems to behave more like a squishy fluid than a rigid plate.” The lesson could be that while ocean plates are rigid, continents might yield and deform under tectonic pressure “a little like a spoon pushing through honey”.
