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