Verifying North Korea hydrogen bomb claim may prove difficult

By Jack Kim and Francois Murphy SEOUL/VIENNA (Reuters) - In the days and weeks ahead, nuclear experts will be hunting for airborne radioactive particles that could shed light on North Korea's assertion that it tested a hydrogen bomb, but drawing an independent conclusion could prove lengthy and difficult. Seismic monitoring stations operated by governments around the world detected an earthquake on Wednesday morning that the U.S. Geological Survey measured at a magnitude of 5.1. The location of