Global Positioning System
Scientists can measure the movement of plates and the rise of the Himalayas through a modern system called Global Positioning
System (GPS). This technique has been used by planes and ships for a long time to determine their position accurately. Recent
advancements in the system has improved its accuracy tremendously and the GPS is a tremendous navigational aid.
To achieve their objective, the scientists first set up several survey points at different places in the Himalayan region. They place
a GPS receiver at each survey point which records its position from several satellites circling the earth above it. Measurements
continuously each time the satellites pass over the survey points. The survey points are linked by radio telemetry and e-mail to
the headquarters. The scientists have used the data thus collected and have measured the relative motion of the points with an
accuracy of 3
Using this technique, the scientists have been able to find that the Indian plate is moving northward at the rate of 18 mm a year
and that the Himalayas are rising at about 5 mm a year.