&quot;tetrapodization&quot; probably refers to the large concrete &quot;tetrapods&quot; piled up along Japan&#x27;s shorelines as a preventative measure against erosion. Google &quot;japan tetrapod&#x27; and you can find a lot of references - here is a Pink Tentacle article with a lot of pictures[0], and another article describing them and their history.[1]<p>[0]<a href="http:&#x2F;&#x2F;pinktentacle.com&#x2F;2008&#x2F;08&#x2F;photos-tetrapod-beaches-of-japan&#x2F;" rel="nofollow">http:&#x2F;&#x2F;pinktentacle.com&#x2F;2008&#x2F;08&#x2F;photos-tetrapod-beaches-of-j...</a><p>[1]<a href="http:&#x2F;&#x2F;www.mikesblender.com&#x2F;tokyo_concretecoast.php" rel="nofollow">http:&#x2F;&#x2F;www.mikesblender.com&#x2F;tokyo_concretecoast.php</a>