Hypocenter Park Nagasaki

In the first map,  'A' marks  Hypocenter park:


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In the second map, 'B' marks Hypocenter Park:

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Here is the link to the infamous mushroom cloud, attributed to Nagasaki. This is on the National Achives World War II web page. This is a much larger file than is normally seen. In this larger picture, more detail can be seen. In smaller pictures, there appears to be one column that rises up, first dark, then abruptly changing to white. In this larger photo, it can be plainly seen that the dark and the white column are actually two different columns. 

The white cloud appears to be rising from an island, or peninsula, in the middle of the photo. The dark column appears to be rising from a beach in the foreground, at the bottom of the photo. The island appears to have a narrow stream of water behind it, and a larger stream in front. The two streams seem to be joining to the left, but it is beyond the border of the photo.

Now, compare this picture to the above maps, and ask yourself if the picture is really that of  Nagasaki.