Giant Clam Shells Found on 1977 Alvin Pacific Sea Floor Dive

In 1977, during the first crewed Alvin dive to the Pacific sea floor, Tjeerd van Andel and his companions made an extraordinary observation. Situated directly around seafloor hot springs, the team encountered heaps of giant white clam shells. These shells were found to measure up to 60 cm long, presenting an unusual sight on the Pacific sea floor.

Finding these items is surprising because shells measuring up to 60 cm long are remarkably large. For an ordinary reader, imagining white clam shells of such an enormous size piled around seafloor hot springs reveals just how unexpected the Pacific sea floor can be. The sheer scale of these 60 cm shells makes them a truly striking visual discovery.

The direct observation by Tjeerd van Andel and his companions highlights what was resting near seafloor hot springs during this 1977 dive. Ultimately, this first crewed Alvin dive brought to light giant white clam shells gathered on the Pacific sea floor, illustrating that seafloor hot springs could be surrounded by massive shell heaps.