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3-D maps of Heceta Bank made from multi-beam data. Top image is about 30 milesnorth to south and 10 miles east-west. The southern part of the bank has aclearly defined western edge marking an ancient shoreline. The bottom image isnorthern shoal portion of bank. The fracture patterns are megajoints causedby stresses in the earth. The curved troughs are caused by variable erosion.