George Tate Retires from the Pacific Coastal and Marine Science Center
After many years of service to the U.S. Geological Survey (USGS), most recently as the chief of the Marine Facility (MarFac) at the USGS Pacific Coastal and Marine Science Center in Santa Cruz, California, geologist and engineer George Tate is retiring. His plans for the future include "chasing waves and trout, sailing fast, and exploring the backcountry and backwaters of places revisited and those not yet traveled." Marine technician Jenny White has taken over his position as MarFac chief (see "New Marine Facility Chief for the Pacific Coastal and Marine Science Center," this issue).
Center Director Robert Rosenbauer said, "I will miss working with George, who has so capably held this position and advised me so well over the years."
George joined the center, then called the Branch of Pacific and Arctic Geology, in 1976. He hit the ground running to help USGS oceanographer Dave Cacchione and geologist Dave Drake (both retired) develop what Cacchione and Drake dubbed the "Geoprobe," a large tripod that holds instruments for collecting data on sediment movement at and near the seafloor. George provided critical input to the development of the tripod, its instrument packages, and the multifunctional data loggers that enable the Geoprobe to record and store large sets of diverse data while sitting on the seafloor for days to months at a time.
Sensors on the Geoprobe measured such variables as current velocity, suspended-sediment concentration, water temperature, and salinity. Video and still cameras captured images of sediment on the seabed and in the water. These data supported studies of numerous topics in diverse settings. For example, in San Francisco Bay, Puget Sound, Oahu's Kailua Bay, and off the coast of southern California, the Geoprobe collected data for studies on how sediment and pollutants move in estuaries and nearshore waters (http://soundwaves.usgs.gov/2000/02/fieldwork.html). Off northern California, the Geoprobe was used to investigate how storm currents and sediment from flooding rivers affect sediment movement near the seabed (http://dx.doi.org/10.1016/0278-4343(94)90038-8) and how sediment layers form and change on the continental shelf (http://soundwaves.usgs.gov/2007/08/pubs.html). George led these deployments and many more—in waters off Alaska, in Australia's Tasman Strait, off the coast of Norway, and near the mouth of the Amazon River.
Designing and deploying instrument packages was just part of the story. Equally important were George's skill and ingenuity in recovering the instruments and their valuable data. He always had an alternate plan in case of equipment failure—using grappling hooks, divers, tethered systems, remotely operated vehicles, whatever was available.
Cacchione recalled one difficult recovery in 1990 off the coast of Brazil. “When the Geoprobe tripod was stuck in the bottom mud on the submerged edge of the Amazon delta, George organized the recovery using a trawling net on a Brazilian shrimp boat. The data provided important new insights on delta growth by large-scale deposition of fluid muds.” (See “Measurements in the bottom boundary layer on the Amazon subaqueous delta”.)
“George is the most talented and innovative marine instrument and shipboard operations person I have ever encountered,” Cacchione said, “and his contributions to sediment-processes research are truly remarkable.”
Drake added: “Without George on the Geoprobe team, I doubt very much that we would have had the tremendous success we enjoyed (or the fun times) over two decades of cutting-edge research. In many ways, George, with key help from Joanne Ferreira, Rick Vail, and Jim Nicholson, made it all happen.”
Together with Cacchione, Drake, and other USGS scientists, George was coauthor on a number of significant scientific papers, including the first recognition of rippled scour depressions on the inner continental shelf off northern California (see “Rippled scour depressions on the inner continental shelf off central California”), a discovery that led to observations of these features around the world and ongoing research into how they form and how they influence the abundance and diversity of sediment-dwelling organisms and juvenile fish.
George's expertise with instrumented tripods applied as well to moorings, lines attached to anchors on the seafloor at one end and surface buoys at the other, with instruments mounted at intervals to measure water temperature and salinity, current velocity, suspended-sediment concentration, and other parameters at various water depths. George worked with moorings in many settings, including off northern California for a study led by Cacchione on internal waves—waves within the ocean at the interface between layers of differing density, analogous to waves at the interface between oil and vinegar in a gently tilted jar of salad dressing. (See an animation of internal waves in the South China Sea at http://video.mit.edu/watch/internal-waves-26948.) The moorings sat on the continental slope—which ramps downward from the continental shelf toward the deep abyssal plain—and collected data indicating that internal waves not only affect sediment movement along the continental slope but also may control its gradient. (See "Internal Tides and the Continental Slope" at http://dx.doi.org/10.1511/2004.2.130.)
George was also indispensable when an instrument developed for use in marine waters was applied in a river. In the 1990s, he deployed a rotating sidescan sonar to collect images of underwater sand dunes moving along the bed of the Colorado River. That work was part of a project led by USGS sedimentologist Dave Rubin (retired) to investigate how Glen Canyon Dam operations affect sediment movement in the Grand Canyon (http://www.gcmrc.gov/).
In the late 1990s, George left the USGS to do consulting work in the private sector. In 2011, Center Director Bob Rosenbauer asked him to return to the Pacific Coastal and Marine Science Center to take over MarFac leadership and, additionally, to become the Center's Deputy Director for Operations.
Once again, George supported the Center's scientific projects and conducted research and development to design tools and techniques used in investigations worldwide. One of George's recent projects, like his earliest work for the USGS, focused on a tripod: George designed a footpad-release mechanism that enables a tripod to rise from the seafloor to the surface without being pulled up by a line. This "free-ascending tripod" can be deployed at much greater water depths than its Geoprobe predecessor (see "Deep-Sea Instrument Tripod Passes Test in Monterey Bay, California—Next Stop is South China Sea" ), enabling the investigation of currents and sediment movement thousands of meters below the ocean surface.
George's retirement concludes a long period of wide-ranging and innovative work with the USGS. "My career trajectory has been beyond anything my wildest imagination may have conjured up back in the 70s," he wrote in a farewell message to center personnel. "Along the way, I have developed strong relationships with many of you, and you will always feel like family to me." He expressed admiration for the center's "scientists, admin professionals, support staff, and center management" who "have been wonderful to work with and an inspiration in their dedication and professionalism as they continue to push back the frontiers of modern science."
Happily, George will continue to spend some time at the USGS over the next year assisting new MarFac chief Jenny White as she wraps up her marine technician commitments while simultaneously assuming leadership of MarFac.
Please join the Pacific Coastal and Marine Science Center in extending our congratulations and thanks to George!
in this issue:
George Tate Retires from the Pacific Coastal and Marine Science Center