The seismic waves created by North Korea's fourth nuclear test on Wednesday were almost identical to the waves generated in its previous test, according to an analyst, undermining Pyongyang's claim to have tested a hydrogen bomb.
"Seismic signals from the January 2016 detonation at the North Korean nuclear facility bear an uncanny resemblance to the signals recorded for the February 12, 2013 detonation," Jeffrey Park, a seismologist at Yale University wrote in a post on the Bulletin of the Atomic Scientists website.
Previous North Korean nuclear tests produced explosions that increased by factors of three or five every time until reaching a size equivalent to a normal atomic bomb in 2013, Park wrote.
The data indicates Wednesday's test used an "identical design," the analyst said.