Scholl was among the first to recognize a peculiar type of seismic reflection, which he named bottom-simulating reflectors (BSRs) and which are now considered to be diagnostic expressions of the bottom of gas-hydrate intervals in marine sediment around the world.
U.S. Geological Survey (USGS) emeritus geologist David W. Scholl has been selected as a Fellow of the American Geophysical Union (AGU), an honor accorded to only 0.1 percent of the AGU membership each year. The selection recognizes Dave’s 40 years as a leading contributor to our understanding of convergent plate boundaries and sediment-hosted gas hydrates.
Dave Scholl is one of the most distinguished marine geologists in the USGS. At age 71 and a USGS Scientist Emeritus since 1995, Dave maintains a remarkable cruise and lecture schedule and continues to add to an enviable publication record: a total of 187 peer-reviewed papers, including 19 publications from the past decade. Dave’s sustained research record includes many world-class discoveries made with his USGS colleagues. Here is a partial list:
Dave was among the first to recognize a peculiar type of seismic reflection, which he named bottom-simulating reflectors (BSRs) and which are now considered to be diagnostic expressions of the bottom of gas-hydrate intervals in marine sediment around the world. He and USGS colleagues first recognized and named the reflection anomalies called VAMPs (short for velocity amplitude) in the Bering Sea, believed to be caused by chimney-like gas columns capped by gas-hydrate deposits.
He pioneered the exploration of the process of oblique subduction beneath the Aleutian Island arc by forearc block rotation, including the formation of submarine rift valleys in the arc platform that govern ocean circulation between the Pacific Ocean and the Bering Sea, and the segmentation of slip in large interplate thrust earthquakes.
He discovered the Meiji sediment drift in the northwestern Pacific Ocean, a huge sediment body between the Aleutian Islands and the Emperor Seamount chain that lies far from potential continental sediment sources and may have implications for the reconstruction of Pacific Plate motions.
An early critic of the assumed fixity of the Hawaiian-Emperor hotspot, Dave helped lead the Ocean Drilling Program (ODP)’s Leg 197 cruise, which showed that such fixity is incompatible with paleomagnetic and radiometric age data from ODP drillcores from the Emperor Seamount chain—another discovery with implications for the reconstruction of Pacific Plate motions. This research is reported in a 2003 paper in Science (v. 301, no. 5636, p. 1064-1069).
Along with Roland von Huene (a USGS marine geophysicist, now retired), Dave pioneered research on the rates of basal subduction-erosion, a process by which material from the base of a continental plate is eroded and carried toward the mantle by the descending oceanic plate. Dave and his colleagues showed that many subduction zones are sites of subduction-erosion, a concept at odds with the commonly held assumption that all subduction zones are sites of accretion.
In addition to his scientific research, Dave has managed, shaped, and guided major national marine programs at the USGS. Today, his leadership and guidance have resulted in his appointment to the Science Planning and Policy Oversight Committee (SPPOC)—the top advisory committee for the Integrated Ocean Drilling Program (successor to ODP; see URL http://www.iodp.org/). Despite his high level of activity, Dave remains a generous mentor and teacher and an active contributor of service to both the USGS and AGU.
The above is an excerpt from the USGS Sound Waves Monthly Newsletter.