Viewing a single comment thread. View all comments

ForeignShower4 OP t1_iqp7sw5 wrote

Reply to comment by CrustalTrudger in What are these weird grid of "holes" off the coast of Antarctica? by ForeignShower4

Why would they put out data with such massive artifacts?

1

CrustalTrudger t1_iqp8jeg wrote

There’s not a lot of bathymetric data in that area in general and broadly Google Earth does a pretty bad job of representing data at the poles. Ie these might not be present if you downloaded the gridded data from a source like GEBCO, but instead come from the way Google Earth is stitching rasters.

1

ForeignShower4 OP t1_iqp93a6 wrote

Well I don't know how to do that. Perhaps if you are curious you can check that out.

1

ForeignShower4 OP t1_iqpj1gx wrote

I just checked on the GEBCO website. I found a map that's from the International Bathymetric Chart of the Southern Ocean Version 2 https://www.pangaea.de/advanced/gmap-dataset.php?id=937574&viewportBBOX=0.0,-90.0,0.0,-50.0.

It shows the same "holes".

1

CrustalTrudger t1_iqqs8tl wrote

Ok, then that narrows it down to sparse/noisy underlying data and some issues with interpolation. If you look at something like the NOAA bathymetry viewer you can see where we have either multi- or singlebeam sounding data. Generally in the area you're looking at we have very few tracks, so the bathymetry is going to be primarily from satellite gravity data (e.g., this). This is a sparse dataset, and one that I would expect to broadly have issues at the poles especially.

At the end of the day, these are clearly a data artifact and anyone who works with gridded topographic/bathymetric data immediately recognizes it as such, but given the available data, it's better than nothing.

1