A Mysterious Trace in Tsushima Strait
Between the Sea of Japan and the East China Sea
• 2026.08.02 | 02:25:29 UTC | Sentinel-2B L2A
• 2026.07.20 | 02:31:41 UTC | Sentinel-2A L1C
• 2025.04.29 | 02:25:29 UTC | Sentinel-2B L2A
Coordinates: 34.698°N, 130.165°E | MGRS: 52SFD 06 40
An interesting phenomenon has been observed in the Tsushima Strait between Japan and South Korea.
At the time of the observation, the area was located within a zone of sun glint – an optical phenomenon that occurs when sunlight is reflected off the water’s surface towards the satellite sensor. Relatively calm water appears bright, whilst choppy water appears darker, making ship’s wakes particularly prominent.
The Sentinel-2 image shows a roughly square structure in the left-hand part of the image and a long, linear trail extending eastwards from there. These features appear unlikely to be of natural origin and could represent the wake of a ship that has performed unusual manoeuvres in otherwise calm waters. However, no ship is visible in the vicinity. The square loop makes the image particularly fascinating.
A ship’s wake consists of several components, including turbulence, foam and bubbles, surface-active substances and thermal effects. Whilst some components disappear within a few minutes, others can persist for much longer. Under the right conditions, a wake can therefore still be visible in the optical spectrum even after the ship itself has left the area.
The mysterious trail could thus be a remnant of a ship’s unusual manoeuvres – captured by Sentinel-2 long after the ship had disappeared from the image.
Further reading
Tsushima Strait (Wikipedia)
Sun Glint (EUMeTrain)
The Science of Sunglint (NASA Earth Observatory)
Sunglint Features, Lake Erie, United States (NASA Earth Observatory)
Wake (physics) (Wikipedia)
Ship Wakes in Optical Images (AMS Publications)
