A small, magnitude 2.7 tremor took place near the Punggye-ri nuclear site, according to South Korea's weather agency, and it did not appear to be man-made, like two others since Pyongyang's powerful September 3 nuclear test.
The sanctions, which could cut off one-third of North Korea's total annual exports of $3 billion, took effect in September, but China enforced the new measures from August 15. They said it wasn't man-made and didn't appear to cause any damage in the area. According to 38 North, a Washington-based project which monitors North Korea, numerous landslides throughout the nuclear test site have been detected via satellite images after the sixth test.
White House chief of staff John Kelly said Thursday Americans should be concerned about North Korea's increasing nuclear and missile capabilities, but he tamped down fears of war. There is also a chance the nuclear tests could trigger a volcanic eruption at Mt. Paektu, which is a mountain about 60 miles away from the Punggye-ri region, CBS reported.
All six nuclear tests have been carried out in this location in the northwest tip of the country. But South Korea's Meteorological Administration says the quake was natural.
Congress was warned Thursday that North Korea is capable of attacking the US today with a nuclear EMP bomb that could indefinitely shut down the electric power grid and kill 90 percent of "all Americans" within a year.
China-U.S. ties have been strained by President Donald Trump's criticism of China's trade practices and by demands that Beijing do more to put pressure on North Korea.
At the height of the standoff between the countries last month, North Korean Foreign Minister Ri Yong Ho told reporters the country could conduct a hydrogen bomb test over the Pacific Ocean.