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Scott M. White
Assistant Professor
Marine Geology and Geophysics
Department of Geological Sciences
University of South Carolina
Office: Earth and Water Sciences 314
Phone: (803) 777-6304
Fax: (803) 777-6610
Email: swhite <at> geol.sc.edu
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SEAFLOOR MAPPING LAB GRADUATE STUDENTS
PUBLICATIONS |
Education
- Ph.D., 2001, University of California - Santa Barbara (Geological
Sciences)
- B.Sc., 1994, University of California - Davis (Geology)
- Complete CV >>
Research Areas
Mid-ocean ridges; Seamounts; Lava flow
morphology; Geologic setting of hydrothermal systems; Collection and
interpretation of marine geophysical data; Remote sensing and seabed
classification; Terrain modeling and GIS
Recent and On-going Projects
Anatomy of
an Overlapping Spreading Center, East Pacific Rise 9 deg North
An overarching goal in the study of mid-ocean
ridges is to understand the linkages in the magmatic system from the deep
mantle source to the eruption of lava on the seafloor. An excellent
opportunity to advance our understanding of these linkages has emerged through
the recent acquisition of detailed information on the distribution of melt at
depth beneath the 9°03’N Overlapping Spreading Center on the East Pacific
Rise. A natural next step is to link this detailed seismic information on melt
distribution to geochemical, geological and hydrothermal variability at the
same site. The main hypothesis of this project is that variations in the depth
and dimensions of the melt sills and variations in melt distribution in the
upper mantle will lead to identifiable characteristics in the spatial
distribution of eruption sites, distinct lava compositions, and hydrothermal
activity. DSL-120A side-scan sonar, with the SM2000 multibeam sonar,
MAPRs, CTD, and magnetometer attached to the vehicle, will be used to
characterize the spatial distribution and eruptive style of lava flow fields
and lava distribution systems, tectonic features, and hydrothermal plumes.
Within the region of the DSL-120A survey the Jason II ROV system
will be deployed for detailed mapping and sampling of smaller areas.
Assessment
of the Size and Volume of the 2006 Eruption of the East Pacific Rise
The 2006 eruption of the East
Pacific Rise presents an unprecedented opportunity to gain insight into the
eruptive processes at mid-ocean ridges. This is the first eruption of a
mid-ocean ridge with comprehensive meter-scale seafloor bathymetry and
side-scan imagery available from prior to the eruption. The objectives of this
proposal are to assess the along and across-axis extent of the eruption,
calculate the volume of the eruption products, and measure changes in seafloor
morphology due to the eruption. Knowing where and how much lava is
emplaced during an eruption is crucial to ultimately understanding the
eruption process. Direct comparison of DSL-120 side-scan and phase bathymetry
from before and after the eruption will detect ~2 m or greater changes in
seafloor topography, identifying lava depocenters and eruptive volumes.
Hydrothermal System Response to Magma Supply and Crustal Thickness Gradients on
the Galapagos Spreading Center
The Galapagos Spreading Center is an
ideal natural experiment on how magma supply and crustal thickness affect the
nature, abundance, and distribution of ridge crest hydrothermal activity, and
interactions between hydrothermal, volcanic, tectonic, and biological processes. In
Dec 2005 - Jan 2006, we surveyed the ridge crest with sonar, water-column, and
video along the GSC, 89.5ºW-94ºW. We discovered the first black smokers on
the GSC and shed new light on how excess heat from mantle plumes is dissipated
along hotspot-influenced spreading centers.
This cruise was featured on the NOAA Ocean Explorer website >>
Seamounts
in the Western Aleutian Island Arc
The main goals of this project are to test ideas about the basic controls on the
volcanic arc output of subduction zones. This project involved a 30 day cruise
in August 2005 aboard the R/V Thompson that involved multibeam mapping and
dredging seamounts in the Aleutian arc from Attu to Unalaska (Dr. Yogodzinski of
USC was chief scienist). This arc makes a good natural laboratory because it has
never been rifted and shows a gradient of convergence angle from east to west,
with strongly oblique convergence in the west. The cruise obtained the first
modern multibeam bathymetric maps of large portions of the Aleutian arc,
discovering a great number of small seamounts, evidence of large volcanic
landslides, and over 50 successful dredges.
Bathymetric
Framework of the North Inlet-Winyah Bay Estuary
The primary goal of this project is a
bathymetric map of the subtidal channels in the North Inlet-Winyah Bay
National Estuarine Research Reserve. This topography will supplement the
existing LiDAR data available for the supra-tidal parts of the estuary.
Mapping is carried out using a 235 kHz single-beam echosounder, DGPS or RTK-GPS
at the USC Marine Geophysics Lab. These maps will provide the framework
for modeling the net flux of nutrients and sediments in the marsh using 3D
hydrodynamic numerical models. Funding for this project is provided
through the USC College of Arts and Sciences, Baruch Institute and the John
Hodges Award.
Understanding and Predicting Resiliency of
Barrier Islands to Hurricanes
This study funded by a minigrant from the USC Office of Research to Dr.
Voulgaris (lead investigator) and White (co-investigator) collected
topographic and sub-bottom profiler data after Hurricane Katrina.
Fieldwork along Caminada-Moreau Headland in Nov. 2005 using RTK-GPS,
bathymetric echosounder, and sub-bottom profiler. Results present an
equivocal case for increased erosion where the seabed had been previously
disturbed more
here>>
Global
Rates and Volumes of Volcanism on Earth
A global compilation of 170 time-averaged
volumetric volcanic output rates are evaluated in terms of composition and
petro-tectonic setting to advance the understanding of long-term rates of
magma generation and eruption on Earth. Repose period between successive
eruptions and intrusive:extrusive ratios were compiled for selected volcanic
centers where long-term (>10,000 yr) data were available. Findings include
that more silicic volcanic centers, rhyolites and andesites, have a more
limited range of eruption rates than basalts. This trend is also seen in the
difference between oceanic and continental settings, as eruptions on oceanic
crust tend to be predominately basaltic. However, we have found no
systematic evidence linking increased intrusive:extrusive ratios with lower
volcanic rates.
>> Download
tables of volcanic rates and volumes >>
S. M. White, R. M.
Haymon, D. J. Fornari, M. R. Perfit, and K. C. Macdonald, Correlation between
volcanic and tectonic segmentation of
fast-spreading ridges: Evidence from volcanic structures and lava morphology on
the East Pacific Rise at 9-10 deg N, Journal
of Geophysical Research, v. 107 n. B8,
2002.
S. M. White, K. C.
Macdonald, and J. M. Sinton, Volcanic mound
fields on the East Pacific Rise, 16-19 deg S: Low effusion rate eruptions for
the past 1 Myr, Journal of Geophysical
Research, v. 107 n. B10,
2002.
S. M. White, J. A.
Crisp, and F. J. Spera, Long-term Volumetric Eruption Rates and Volcanic
Budgets, G-cubed, v. 7 n. 3, 2006. (supplementary
data tables)
Graduate Students
John O'Brien, MSc expected Spring 2008 - Magnetic
structure of OSC crust at the East Pacific Rise
Jason Meyer, MSc Summer 2006 - Expert system
classification of high-resolution side scan sonar at the East Pacific Rise and
Galapagos Spreading Center
Erin Carter, MSc Spring 2006 -
Variations in Salinity across a Forest-Saltmarsh Boundary from
Seafloor Mapping Lab @ Carolina
This lab contains facilities for data collection and post-processing
that are available to the USC community and collaborators at other
academic institutions. Our computer resources include
ArcGIS,
ENVI, and
Matlab through the campus license,
Chesapeake Technology's Sonar.Wiz MAP, Kingdom Suite, and
Generic Mapping Tools and
MB-system.
Geophysical Instruments:
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