BY A STAFF REPORTER: According to the National Centre for Seismology (NCS), an earthquake measuring 4.3 on the Richter scale struck 140 km southwest of Siliguri in the early hours of Wednesday. According to the NCS, the earthquake struck at 5:35 am on Wednesday. According to the National Center for Seismology, the earthquake struck at a depth of 10 kilometers from the earth's surface.