Dean Livelybrooks (aka 'Dr. D.') reporting on 1-September, 2014.
We're getting ready to start a 20 day cruise aboard the Oregon State University-operated R/V Oceanus, departing from Newport, Oregon. Our mission is to deploy 29 ocean-bottom seismometers ("OBS's") that will sit in dark solitude for the next year recording seismic signals and water pressure changes on the Juan de Fuca and Gorda tectonic plates offshore from the Pacific Northwest. We are also charged with recovering 15 other OBSs that have done just that, so that data can be recovered and the instruments refurbished for their next mission.
We are sailing for the Cascadia Initiative Expedition Team (CIET)-- a five-year program to monitor seismic, pressure and (land-based) GPS signals in Cascadia-- a tectonically-active area encompassing oceanic plate creation at submarine ridges; subduction below the North American plate; infrequent, giant earthquakes; semi-periodic 'slow earthquakes' that you can't even feel; and volcano formation and eruptions in the Cascade Range-- ergo the name. We will be deploying or recovering 4 types of OBSs-- all developed by Lamont-Doherty Earth Observatory (LDEO), though other CIET cruises deploy and recover OBS's designed and operated by Woods Hole Oceanographic Institution and Scripps Institute of Oceanography. Two of these types of OBS's, along with the CIET-deployed 'Abalones' from Scripps, have been developed for the special conditions of shallow water deployment on the continental shelf, a first for marine seismology. We call these "TRM's" (for trawl-resistant mount) as they are designed to continue recording even when a fishing trawl net passes over them. Here's a picture of a TRM on the ocean bottom taken by ROV JASON during last season's recovery cruise aboard Atlantis:
Well, I'll sign off for now. Look for more about the scientific objectives of CIET and impressions of life at sea from our crack team of Oceanus sailors, coming soon. Dr. D.