Scientists: Underwater volcano off Oregon Coast will erupt again soon
Spider crab on a hydrophone
A spider crab inspects an ocean-bottom hydrophone (OBH) as it sits on the seafloor at Axial Seamount before the 2011 eruption. The OBH is a monitoring instrument designed to detect undersea earthquakes. The chain is connected to flotation above the view of the photo. (Image credit: Bill Chadwick, Oregon State University)