This is a satellite image of North Korea's Punggye-ri nuclear test site taken before Pyongyang conducted its third nuclear test on Tuesday.

Late last month, there were signs the North was preparing for nuclear tests at two underground tunnels, one on the west side and one on the south side.

The South Korean government has come to the conclusion the communist state conducted the test at the west underground tunnel.

This means Pyongyang could possibly carry out an additional test at the SOUTH tunnel.

The underground tunnels at Punggye-ri are equipped with high-tech facilities, such as measuring instruments and remote detonators, which North Korea uses to gather information to upgrade their nuclear weapons.

However, the problem is that this equipment is sensitive to humidity and temperature.

Analysts say it is highly likely they'll break down if they are left in the deep underground tunnels for a prolonged period of time.



(Korean)

"The measuring devices are in an underground tunnel, where it is difficult to control humidity and temperature. So this is why North Korea will be desperate to carry out another test within the next few days."



The South Korean military are continuing to keep a close eye on any additional movements at the Punggye-ri complex.



(Korean)

"We are staking out the site as there could be an additional test within 48 to 72 hours from Wednesday."



President-elect Park Geun-hye says North Korea won't be able to strengthen its bargaining power by conducting more nuclear tests.



(Korean)

"North Korea will eventually bring collapse upon itself even if the regime strengthens its nuclear capability through numerous tests as it will only use up its national power."



She also made it clear that her pledge to restore confidence between the two Koreas is based on strong nuclear control, not appeasement.

Eoh Jin-joo, Arirang News.

Reporter : jjeoh@arirang.co.kr