abyssal plain
... that using a continuously recording fathometer, WHOI scientists aboard RV Atlantis located and described the first abyssal plain in 1947?
... that using a continuously recording <a href="./Fishfinder" id="mwGk0" rel="mw:WikiLink" title="Fishfinder">fathometer</a>, <a href="./Woods_Hole_Oceanographic_Institution" id="mwGk4" rel="mw:WikiLink" title="Woods Hole Oceanographic Institution">WHOI</a> scientists aboard <a href="./RV_Atlantis" id="mwGk8" rel="mw:WikiLink" title="RV Atlantis">RV <i id="mwGlA">Atlantis</i></a> located and described the first <b id="mwGlE"><a href="./List_of_submarine_topographical_features" id="mwGlI" rel="mw:WikiLink" title="List of submarine topographical features">abyssal plain</a></b> in 1947?