A 38 North exclusive with analysis by Jack Liu

Since speculation that North Korea was on the verge of conducting its fourth nuclear test in late April 2014, activity at the Punggye-ri Nuclear Test Site has come to a standstill. Recent commercial satellite imagery indicates that there is virtually no activity at either area where North Korea might conduct its next blast, or at the facility that would serve as the main support area for a future test.

The meaning of this diminished activity remains unclear. One possibility is that test site personnel may have completed whatever initial preparations are necessary for conducting a fourth nuclear test once Pyongyang gives the order to test. (That may include finishing excavation of a third nuclear test tunnel that has been under construction at the West Portal area in addition to two already finished at the South Portal area.)

Once the order is given to proceed, based on past limited experience, it would take the North approximately six to eight weeks to conduct a detonation. Whether site personnel could move more quickly if initial preparations were completed this last spring remains uncertain. However, it is likely that a spurt of activity would be observable during the run-up to another detonation.

July satellite imagery indicates the following:

There appears to have been no activity at the two complete test tunnels in the South Portal area. The spoil pile has remained unchanged since May. Material may be present near the east tunnel entrance. Its purpose remains unclear, although one possibility is that it is intended for finishing the tunnel walls or cabling to the test chamber. If there is similar material along the west tunnel entrance area, the foliage blocks the view (figure 1).

At the West Portal area, after months of excavation at a third tunnel entrance, there has been no major digging since late May 2014 and no vehicles or activities in or around the portals since July. The site appears to be guarded—an awning or canopy has been erected at the guard shack at the entrance to the area—while the North Koreans may be growing vegetables on the hillside. One possible explanation is that site personnel have completed digging the third tunnel and are now maintaining it for when an order is given to move forward with a nuclear test (figure 2).

There is no discernible activity at the Main Support Area where personnel and equipment are located prior to a detonation (figure 3).

Figure 1. No activity at South Portal tunnel entrances.

Images include material Pleiades © CNES 2014. Distribution Airbus DS / Spot Image, all rights reserved. For media licensing options, please contact [email protected].

Figure 2. Halted activity at West Portal Area.

Images include material Pleiades © CNES 2014. Distribution Airbus DS / Spot Image, all rights reserved. For media licensing options, please contact [email protected].

Figure 3. No discernible activity at the Main Support Area.