An international team of seismologists, comprising researchers from seven countries in America, Europe and Asia, recently completed a three year long seismic survery of Tibet with broadband instruments. The goal of this extensive field deployment, under the acronym Hi-CLIMB (Himalayan-Tibetan Continental Lithosphere during Mountain Building), was to study the results of the collision between the Indian subcontinent and the Eurasian plate. It gave rise not only to the Himalayas but also to the Tibetan Plataeu, commonly known as the Roof of the World.
During the course of the study, the group deployed seismic sensors at a total of 230 sites. Among them were 30 sites at altitudes of 5,000 m (16,400 ft) or more. The instruments used came from the instrument pool administered by Iris-Passcal in Socorro (New Mexico, USA) and from several Chinese research institutions.
One of the highest sites was a seismic station at the basecamp on the Tibetan side of Mount Everest at an elevation of more than 5,200 m (more than 17,000 ft) above sea level (see photo, below). At the heart of the station was a Guralp CMG-3ESP compact sensor, which is part of the instrument pool at Peking University (Beijing). This sensor performed flawlessly during its deployment close to the Top of the World. John Nábělek, the Principal Hi-CLIMB Investigator from Oregon State University in Corvallis (USA), comments that the data of all stations “were generally ok, but we also faced various problems due to high elevation and terrible roads”.
The first results of the study were recently published in "Science" (Vol. 325, pg 1371) by John Nábělek et al. under the title “Underplating in the Himalaya-Tibet Collision Zone Revealed by the Hi-CLIMB Experiment”.
