Why does some part of the ocean floor look so scratchy?

If you look at Google Earth image of the Indian ocean floor, especially the area south-west of Sumatra, it looks like some cosmic beast scratched it with its sharp claws. The same thing can be seen near the Hawaiian islands. I know it has something to do with tectonic movements and stuff, but I don't know for sure.

The sea floor around Cocos Islands

The sea floor around Cocos Islands
So what is the explanation for this?!

  • 3
    $\begingroup$ Can you add a screenshot of Google Earth showing us the feature you're talking about? $\endgroup$
    – Gimelist
    Jun 17, 2021 at 12:37
  • $\begingroup$ @Gimelist Possibly this image, the Ninety East Ridge? The ridges and troughs west of the Ninety East Ridge that roughly parallel the Ninety East Ridge are probably what the OP is asking about. $\endgroup$ Jun 17, 2021 at 14:59
  • $\begingroup$ Unfortunately, I suspect this is a drive-by question. $\endgroup$ Jun 17, 2021 at 15:00
  • $\begingroup$ Possibly also a duplicate of earthscience.stackexchange.com/questions/17277/… $\endgroup$ Jun 17, 2021 at 15:55
  • $\begingroup$ @David Hammen Yes I am talking about exactly those parallel lines. $\endgroup$
    – user22796
    Jun 18, 2021 at 8:03

1 Answer 1


If I am understanding the question correctly those straight lines may not actually be lines, they may be strips or bands and they are bands that are not actually there. The bands are a result of combining the available sea floor profile data into a single map and are bands of sea bottom that follow the course of ships that do such mapping - thus the straight part - at higher resolution than the areas around them. Zoom in close and the different resolutions within and outside those bands become easier to identify.

Or else it is the patterning of ocean bottom accompanying the boundaries of tectonic plates that have histories of diverging. I'm not sure why such patterns emerge; someone better informed may be able to answer better.

  • 2
    $\begingroup$ There are lots of real ridges and troughs to the west of the 90 East Ridge that more or less parallel the 90 East Ridge. I suspect that these lesser ridges and troughs to the west of the 90 East Ridge are what the OP was asking about. $\endgroup$ Jun 17, 2021 at 15:05
  • $\begingroup$ See also earthscience.stackexchange.com/questions/17277/… for the mapping aspect of it. $\endgroup$ Jun 17, 2021 at 15:56
  • $\begingroup$ @DavidHammen - if it is about those ridges, then the Q definitely needs a better answer than mine. $\endgroup$
    – Ken Fabian
    Jun 18, 2021 at 0:08
  • $\begingroup$ @KenFabian The question definitely needs improvement. But we haven't seen the OP since shortly after the question was asked. $\endgroup$ Jun 18, 2021 at 1:54
  • $\begingroup$ I don't think those are graphics artifacts. I believe those are real troughs and ridges. A little googling and my limited intuition suggests that these ridges may have formed due to lava flow and techtonic pressure on Earth's crust. $\endgroup$
    – user22796
    Jun 18, 2021 at 8:11

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