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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

enter image description here

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

enter image description here

The csv format looks like this (in qgis)

enter image description here

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

enter image description here

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 '18 at 17:57
  • Yes, sorry I hadn't finished the post when i made it :) – Ewan Mar 25 '18 at 18:06
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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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