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I am trying to produce an earthquake map of the south-west pacific ocean area around New Zealand and its surrounding islands.

In order to produce a map which crosses the antimeridian, I took two ASTER dtm products and reprojected them from Pseudo Mercator EPSG:3857 to PDC Mercator EPSG:3832 which is centred on the pacific ocean

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I added my earthquake data in csv format as points in EPSG:3857 and used 'save-as' to save as shapefile and then 'save-as' again to reproject them to EPSG:3832, however they still plot in exactly the same place, completely off from my reprojected dtm and at the wrong scale

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The csv format looks like this (in qgis)

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and they plot perfectly when i'm not trying to cross the antimeridian

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Hopefully someone has an idea of what's going on and how to solve it..

I have also tried to use a layer extent to help when reprojecting the shapefiles but all this seems to do is cause me to lose all the data that is stored in the attribute tables!

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    Can you add sample lines of the original CSV file? It might be the coordinates are in lonlat degrees, not EPSG:3857.
    – AndreJ
    Mar 25, 2018 at 17:57
  • Yes, sorry I hadn't finished the post when i made it :)
    – Ewan
    Mar 25, 2018 at 18:06

1 Answer 1

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As AndreJ guessed, your data is in WGS84, not PseudoMercator. Try with EPSG:4326 instead.

Also, you do not have to use "save as" to actually convert your data, it is possible to reproject on-the-fly, you just have to specify the correct coordinate system for each layer.

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