In the bottom left corner of each image you’ll also see a month and year that tells you when a particular photograph was taken. When looking at images of the magnificent cities side-by-side with images of the ruins left in their place, this additional context demonstrates how truly life-changing this tragedy has been for those who live there and witnessed the destruction of their homes, neighborhoods and even entire districts.
In the case of the post-tsunami imagery of Japan, we hope this particular digital archiving project will be useful to researchers and scientists who study the effects of natural disasters. We also believe that the imagery is a useful tool for anyone around the world who wants to better understand the extent of the damage. Seeing the street-level imagery of the affected areas puts the plight of these communities into perspective and ensures that the memories of the disaster remain relevant and tangible for future generations.
Source: Google Blog