Earth Matters

April Puzzler

April 18th, 2016 by Kathryn Hansen


Every month on Earth Matters, we offer a puzzling satellite image. The April 2016 puzzler is above. Your challenge is to use the comments section to tell us what part of the world we are looking at, when the image was acquired, what the image shows, and why the scene is interesting.

How to answer. Your answer can be a few words or several paragraphs. (Try to keep it shorter than 200 words). You might simply tell us what part of the world an image shows. Or you can dig deeper and explain what satellite and instrument produced the image, what spectral bands were used to create it, or what is compelling about some obscure speck in the far corner of an image. If you think something is interesting or noteworthy, tell us about it.

The prize. We can’t offer prize money, but, we can promise you credit and glory (well, maybe just credit). Roughly one week after a puzzler image appears on this blog, we will post an annotated and captioned version as our Image of the Day. In the credits, we’ll acknowledge the person who was first to correctly ID the image. We’ll also recognize people who offer the most interesting tidbits of information about the geological, meteorological, or human processes that have played a role in molding the landscape. Please include your preferred name or alias with your comment. If you work for or attend an institution that you want us to recognize, please mention that as well.

Recent winners. If you’ve won the puzzler in the last few months or work in geospatial imaging, please sit on your hands for at least a day to give others a chance to play.

Releasing Comments. Savvy readers have solved some of our puzzlers after only a few minutes or hours. To give more people a chance to play, we may wait between 24-48 hours before posting the answers we receive in the comment thread.

Good luck!

Update: The answer is posted here.

32 Responses to “April Puzzler”

  1. Jaouhar MOSBAHI says:

    place: Caspian Sea
    Time: 6 april
    satelitte : LandSat 8 /OLI

  2. yanie cocamas says:


  3. MOHIT says:

    Two islands in the sea or ocean with white lines are movements of marine animals.

  4. Amit Yadav says:

    Sargasso sea…. Green alage boom pic

  5. Synn Cloud says:

    it could be in dubai…
    those man made islands?
    since it looks like the african continent just miniature size….
    this photo is confusing though

  6. Daniel Wood says:

    Gulf of California….Giant Kelp forests?

  7. Jwely says:

    This image is of small reef covered islands in the Tyuleniy Archipelago in the northern Caspian sea, just northeast of Bautino, Kazakhstan. I think the bright blue streaks are highlighted by the coastal blue band and indicate suspended sediment. I’d guess that the sediment is being kicked up by caspian seals as they hunt small bottom feeders, but I’m not sure.

  8. Fahad ghannam says:

    Saudi Arabia

  9. ketaki satpute says:

    The images shows landmasof Africa and its nearby water bodies.

  10. Crystal says:

    Somewhere in the Arctic Ocean in Northern BC, Canada
    Time laps photo of a pod of Beluga whales feasting on a large school of fish (maybe Mackerel)

  11. Hortense says:

    Norway .part of it.

  12. Francis says:

    This is a phosphorescent bay in the Caribbean, possibly around the islands of Viques, Puerto Rico or Culebra, Puerto Rico. The lines are the paths of moving marine life (accounting for their different widths). The phosphorescent organisms are stimulated (“lit”) by motion/movement, highlighting the paths taken by PRthe marine life.

  13. Francis says:

    Vieques, Puerto Rico*

  14. Situ says:

    The Green mass to the Left is Africa and to the right is Madagascsr. Seems to be imagery of the South India Ocean. The two brown shapes indicate tropical climate anamolies or weather systems using some sort of satellite imagery. Could be two similar weather patterns or atmospheric conditions whilst the green area indicates normal expected weather.

  15. James Varghese says:

    The Image was taken over Caspian Sea, sometime in April with Landsat 8 Operational Land Imager (OLI) sensor. Seems like a True Colour Composite. The satellite image seems to show marks made by ice on the sea floor. It is interesting because generally it is not so easy to see the sea floors with the help of a satellite image unless the waters are shallow and clear. Beautiful sea floor geology at display. Generally such marks are formed when floating ice touches shallower sea floors or sea beds and when they are still drifting across producing gouges. The Image is only a subset of the whole Landsat 8 scene acquired on 6th April, 2016. Those two land masses are part of the Tyuleniy Archipelago in the Caspian Sea. The full Landsat 8 scene can be downloaded from Here is a screenshot of the whole Landsat 8 scene
    Another interesting thing is that the two landmasses in the image resembles continents of Africa and South America though not to scale and the blue green colored ocean resembles Atlantic ocean in between.

  16. Chiranjeevi says:

    North Atlantic ocean between North America and Europe

  17. drew says:

    south sea islands below lines of seeded clouds or chemtrails

  18. Rachel says:

    I agree with Jwely on the location. But I suspect the marks are scrapes on the sea bed from wind-blown ice. Winters here are exceedingly cold, and this part of the Caspian ices over. Since it’s also very shallow, for some of the winter the ice is grounded. However during the thaw the ice breaks up, and winds can blow the icebergs around, scraping the undersides across the sea bed and forming sets of parallel scrape marks.

  19. Deddy Djanawir says:

    Caspian Sea
    Tyuleniy Archipelago
    Still not sure what the white streaks are. Possibly related to Seals movements across the sea.

  20. Yolanda says:

    Northen Caspian Sea.

  21. DMI says:

    The image shows two islands of Tyuleniy Archipelago in the northern Caspian sea. I guess it’s Landsat-8 OLI true color image (R, G, B) acquired on Apr. 14 but could be also been acquired on Apr. 7, 9 , 11 and 12. The filaments looks like sediments and phytoplancton present in the waters around the islands.

  22. Ellen says:

    Prop scars.

  23. lakhwinder singh says:

    Islands in south ocean, near Atlantic . Colour is due to calcium carbonate .

  24. Bahuleya Kumar. says:

    Images of African continent and India. The lines are passing of meteors,

  25. Femke de Jong says:

    The lines are caused by breaking waves in a long expose image.

  26. Gort Biedermann says:

    Others have pointed out that this is most likely the North Caspian Sea, photographed recently by Landsat 8. I take no credit for figuring that out. There still seems to be controversy over the white streaks. I believe that the streaks show the movement of ice chunks and slush. Someone may have asserted that earlier too. In previous decades, this area of the Caspian Sea would be covered with a sheet of ice at this time of year. But now, due to three things: 1) global climate change, 2) shallowing of the Caspian Sea, and 3) increased salinity of the Caspian Sea; the ice breaks up easily, and chunks just get blown around the surface by the wind.

    The thicker, fluffy trails are probably clouds.

    This appears to be a composite time-lapse showing the movement of the ice chunks and clouds over a period of 1 hour or so. Sophisticated super-imposition software was probably used to compose the image.

    Now here is a question — Does Landsat 8 have the type of orbit which allows photographing a 1-hour time-lapse sequence?

    • James Varghese says:

      Hi Gort, interesting analysis.
      I would like to try answering the question you raised. Landsat 8’s orbit does not allow it to have a 1-hour time-lapse sequence. It takes instant images. To image the exact same spot of the Earth it needs to come back every 16 days after completing the cycle of imaging the whole Earth covering pole to pole (Polar Orbits). Therefore I think, probably the lines were created by ice last winter (say December, January ..) and now during spring the ice may have melted exposing the marks left behind by ice, probably.

  27. Gort Biedermann says:

    Please add to my previous comment:

    Jwely and Rachel preceded my reply. However I don’t think there is any scraping of the sea floor. The ice is probably only a few feet thick.

  28. Gort Biedermann says:

    Sorry I am adding more:

    There is a fourth and fifth reason why the ice breaks up into small chunks so readily 4) Hundreds of ships constantly zigzagging all over that region, participating in intense oil exploration activities, and 5) Construction of man-made islands to support buildings, offices, and barracks for oil company employees.

  29. James Varghese says:

    I have already provided an answer earlier, however I have some of my own questions.

    How do you differentiate between gouge marks left by ice bergs (naturally) on sea floors and the ones created by trawling and mooring (human activities) via Landsat 8 satellite images for example? I assume both activities disturb marine ecosystem within the Seas? Any ideas are welcome.

  30. TarkioBird says:

    Sea monster.