Geography of Greece. It is a peninsular and mountainous country located in Southern-Eastern Europe, in the Balkans peninsula. The country has the largest coastline in Europe (13,676km) due to its numerous islands. Greece has a total of 2,000 Greek islands but only 168 are inhabited.
Harry Hess created the theory of plate tectonics moving along the ocean's floor.
Sea-floor spreading  In the early 1960s, Princeton geologist Harry Hess proposed the hypothesis of sea-floor spreading, in which basaltic magma from the mantle rises to create new ocean floor at mid-ocean ridges.