University of Delaware
Thomas
Church, Professor of Oceanography and Chemistry,
UD College of Marine Studies. Phone: (302)
831-2558 E-Mail:
tchurch@udel.edu
A marine chemist, Dr. Church was involved
in research
on the Corinthos oil
spill,
which
released
more
than
500,000
gallons
of
crude
oil
in the
Delaware
River
near
Marcus
Hook
on January
31,
1975.
It was
offloading
a crude
oil
cargo
when
it was
rammed
by the
Edgar
M. Queenie. The resulting explosion and
fire
released
more
than
500,000
gallons
of oil
to the
river.
“Our
group
performed
research
on tracing
spilled
oil
in the
Delaware
Bay
by using
trace
metals,
as reported
by G.
Leon
in his
M.S.
thesis,"
Church
notes.
"That
other
large
spill,
from
the
Corinthos during
the
late
1970s,
was
in the
same
vicinity
as the Athos, and
also
carried
a heavy
crude/residual
oil.
Although
there
was
not
much
oil
seen
below
Pea
Patch
Island
from
surface
slicks,
our
metal
tracers
(Ni
and
V),
detected
it farther
south," he
says. "That
spill
like
this
one
was
in the
winter,
and
consisted
of heavy
crude
that
went
largely
to the
bottom. I
doubt
that
there
will
be much
if any
impact
or particular
danger
to southern
Delaware
coastlines.
A much
larger
question
is why
single-bottom-hulled
tankers
are
allowed
in the
bay
at all.
This
would
not
be permitted
in the
European
Union
ports. We
cannot
afford
to witness
another
large
spill
in the
upper
bay
because
of such
short-sighted
legislation!" "
In
1976
and
1977,
UD
marine
scientists
and
graduate
students
published
a series
of reports,
funded
by
the
National
Science
Foundation's
Research
Applied
to
National
Needs
(RANN), based
on their
research
on the
Corinthos
spill.
They
included
"Field
Investigations
of Convergences
and
Slick
Concentration
Mechanisms
in Delaware
Bay"
by C.
C. Sarabun,
Jr.;
"Trace
Metals
in Petroleum:
A Tool
for
Minitoring
Estuarine
Oil
Spills"
by Gerald
M. Leone
and
Thomas
M.
Church;
"Modeling
of Oil
Evaporation
in an
Aqueous
Environment"
by Hsiang
Wang,
Wei
C. Yang,
and
C. P.
Huang;
"Remote
Sensing
of Estuarine
Fronts
and
Their
Effects
on Oil
Slicks"
by V.
Klemas
and
D. F.
Polis;
and
"Computer
Modeling
of Oil
Drift
and
Spreading
in Delaware
Bay"
by Hsiang
Wang,
John
R. Campbell,
and
John
D. Ditmars.
James
Corbett, Assistant Professor of Marine Policy, UD College of Marine
Studies. Phone: (302) 831-0768 E-Mail: jcorbett@udel.edu
Dr. Corbett’s background includes operating oil tankers in the U.S.
fleet as a licensed marine engineer. He has degrees in marine engineering,
mechanical engineering, and public policy. He has previous
experience and training supporting the Navy On-Scene Commander with regard
to spills and disaster response. He also is an active researcher and instructor
in the area of marine transportation, environment, and technology policy. You
can read a recent popular article about his research in the UD Messenger.
Corbett has detailed knowledge of the ships that visit the ports on the Delaware
River and Bay, where they come from, and what cargo they carry, as well as
major issues facing the marine transportation industry — from port security
to ship pollution.
“The Delaware River is a major node in the U.S. Marine Transportation System, an extensive network of ports and highways that carries consumer goods,” Corbett says. “Some 67% of the products purchased by Americans move along this system.”
Trade growth projections remain strong, Corbett says, which means that concerns
about port security, pollution, aquatic species invasions, and other issues
associated with the 2 billion tons of domestic and international freight currently
handled by the Marine
Transportation System are likely to become even more important.
“The system faces critical policy decisions that require an understanding of science, technology, economics, and the environment to help set future priorities,” he notes.
Currently, Corbett is involved in a cooperative study with Rutgers University
to evaluate public-private incentives to reduce emissions from New York Harbor
ferries. He is also leading research projects related to ballast water policy,
risk assessment of whale collisions with ships, and energy use in marine transportation.
In recent work relating to cargo and passenger vessels, he determined that
ships could reduce emissions by as much as 80–95% depending on the policies
and technologies implemented. His research has been cited in policies developed
by the International Maritime Organization and the U.S. Environmental Protection
Agency.
Charles
Epifanio, Professor of Marine Biology-Biochemistry, UD College of Marine
Studies. Phone: (302) 645-4272 E-mail: epi@udel.edu
Dr. Epifanio has conducted over 20 years of research on the marine life of
the Delaware Bay and Delaware’s Inland Bays, with particular emphasis
on the blue crab, the bay’s largest commercial fishery. He also conducts
research on other crab species found in Delaware Bay including the mud crab,
a key predator of oysters, and the Japanese shore crab, a non-native species
that now inhabits the bay. Click
here for a research brief on Epifanio's
current NOAA Sea Grant work, with colleagues Richard Garvine and Charles Tilburg,
on developing a predictive model for the supply of larval blue crabs. You can
read a recent popular article about his research in the UD
Messenger.
“If the oil spill had occurred in early spring,” he says, “it
would have coincided with striped bass spawning, which occurs in that area.
If it had occurred in late spring, it would have coincided with weakfish spawning,
which occurs farther downstream in the main bay -- but with associated upstream
migration of juveniles.
“If the oil spill had occurred in summer,” he continues, “it
would have coincided with occupation of the region by juvenile blue crabs and
adult male blue crabs. These have probably (and I emphasize probably)
already migrated to deeper water in the main bay where they will hibernate
for the winter.
“Overall, I believe the measurable effects on the main bay will be minimal,
but the local effects at the spill site will be serious,” he notes.
Richard
Garvine, Maxwell P. and Mildred H. Harrington Professor of Marine Studies,
UD College of Marine Studies. Phone: (302) 831-2169 E-mail: rgarvine@udel.edu
On the UD faculty since 1977, Dr. Garvine conducts research and teaches graduate
courses on the circulation of the coastal ocean, estuaries and geophysical
fluid dynamics. Among his accomplishments, he discovered the Delaware Coastal
Current, which flows out of Delaware Bay and then turns right, hugging the
coast. You can read a recent popular article about his research
in the UD
Messenger.
He provides the following analysis of the Delaware River and Bay's circulation:
"From our group’s
study of the circulation and mixing of water in the Delaware Estuary (the
Delaware Bay and the tidal portion of the Delaware River, which extends to
the falls at Trenton, New Jersey) over the past two decades, we have assembled
a coherent view of how estuarine circulation works in general.
The dominant source of current in the estuary is the tidal period (12.4
hr) rise and fall of the water level impressed on the estuary’s mouth
by the tidal variations on the adjacent continental shelf. Typical tidal currents
in the estuary are about 0.8 meters/second or about 1.5 mph. The mechanism
creating the next rank of tidal current is the horizontal difference in water
density between the fresh water in the Delaware River and the heavier water
seaward in the estuary where shelf water has intruded at depth and mixed upward
with seaward flowing fresh water. This force creates a strong conveyor belt-like
circulation pattern in the vertical with the lighter water passing through
seaward in the upper half of the water depth and landward in the bottom half.
A similar circulation is established in a room with a wood stove in operation.
Hotter (less dense) air rises and travels upward along the ceiling while (more
dense) air sinks and travels along the floor inward toward the stove. Typical
current speeds for density-driven circulation in the Delaware estuary are about
0.05 to 0.10 m/s or about 0.1 to 0.2 mph.
Wind produces current, also. Wind
from the northwest induces a seaward flow for the upper 2/3 of the water depth
and a landward flow in the lower 1/3 with typical speeds the same as the density
driven flow. The directions reverse for wind from the southeast. But there
is a special twist to the wind-forced current. Strong winds from the southwest
impact the estuary little, as they are crosswinds there, while on the shelf
nearby they produce coastal upwelling and falling sea level. This is imposed
on the estuary mouth causing falling water levels there, too. In the reverse
with winds from the northeast (as in a ‘northeaster’), sea-level
rise results, often with coastal flooding. Currents in the estuary then reflect
this water-level change by flowing landward in northeasters and seaward in
southwesterly winds. The speeds from this action are a fraction of the locally
driven winds discussed above.
In the estuary, the strong tidal currents themselves with daily and twice-daily periods produce a steady or very slowly varying current called the tidal residual. This flow is weaker at about 0.05 mph, but makes up in persistence by its long term of activity in transporting materials, including petroleum. Last in intensity is the current driven by the water added to the estuary by its tributaries, the largest being the Delaware River. This flow drifts seaward at all depths much like water running downhill in a rain gutter. Typical speeds are 0.005 mph or about 0.25 miles/day.
Averaging over the tides, we find under most conditions a net seaward flow,
especially in the upper half of the depth. Most of the oil from a spill will
be in this part of the water column, and we can expect typical current speeds
of 0.1-0.2 mph or about 2-5 miles per day.
Once at the mouth at Cape Henlopen, the flow continues into the waters
of the continental shelf, but because of the action of the Earth’s rotation
(Coriolis force) it turns right and continues to follow the coast of Delmarva
sometimes as far south as the mouth of Chesapeake Bay. We refer to this
feature as the Delaware Coastal Current. If it originally was transporting
oil at the mouth of Delaware Bay, it will likely distribute that oil while
gliding along the coast. If southwesterly winds blow, however, sea level falls
at the coast in connection with offshore movement of the surface water. This
transports oil and water offshore with rapid mixing with coastal seawater.
Our group has applied a mathematical numerical model of the circulation and
mixing of the Delaware Estuary and Delaware Coastal Current that has given
good agreement when tested against field observations. We are planning to use
this model to study mixing of fresh water from the Delaware estuary with the
seawater on the continental shelf. Then we will apply the model to the
detailed transport of oil seeking to simulate a spill in the estuary. Results
from this modeling effort are expected by 2006."
John
Madsen, Professor, UD Department of Geology.
Phone: (302) 831-2569 E-mail: jmadsen@udel.edu
Dr. Madsen provides information on an upcoming research project.
Benthic
and Sub-Benthic Mapping of Delaware's Coastal Areas for Natural Resource
Management: This project will couple the use of three acoustical
devices to identify and map the benthic habitat and sub-benthic stratigraphy
of the nearshore area of the western portion of Delaware Bay. For more
information, please click on the project title.
Jonathan
H. Sharp, Professor of Oceanography, UD College of Marine Studies.
Phone: (302) 645-4259 E-mail: jsharp@udel.edu
Dr. Sharp has conducted consistent research
sampling along the entire length of the Delaware Estuary (from head of tides
in Trenton to mouth of Delaware Bay) for over 25 years. He also has conducted
considerable evaluation of the long-term monitoring data from the Delaware
River Basin Commission (DRBC) (from head of tides to lower bay, 1967-present).
"My
research is on microbial biogeochemistry, specifically in relation to major
biologically active elements -- this includes primary production, nutrient
enrichment, and dissolved oxygen dynamics," he says. "The DRBC
database is for water-quality chemistry. It would be possible with some current
sampling to see changes in water-quality chemistry and primary production. However,
this is a time of year when biological activity is minimal. Probably,
it will be more important to assess the impacts next spring and summer; I
will have a research cruise in March 2005 and DRBC routine monitoring will
resume in March." For more information on Dr. Sharp's current research,
please see his Web page.
Over the years, he has worked closely
with DNREC (also NJ DEP and PA DEP), DRBC, NOAA, U.S. Fish and Wildlife, and
the Army Corps of Engineers on various aspects of science of the Delaware Estuary. He
chaired the Science and Technical Advisory Committee for the Delaware Estuary
Program in its planning stages (1989-1996) and was the original chair of the
Board of Directors of the Partnership for the Delaware Estuary (1996-1999).
He also has served on several advisory committees for the DRBC including water-quality
modeling and monitoring.
Christopher
K. Sommerfield, Assistant Professor of Oceanography, UD College of
Marine Studies. Phone: (302) 645-4255 E-mail: cs@udel.edu
Christopher K. Sommerfield is a geological oceanographer specializing in estuarine,
coastal, and shelf sedimentary processes. His research considers how
sediment transport, accumulation, and erosion affect the geomorphology and
shallow stratigraphy of the seafloor. Click
here for a research brief on Sommerfield's current NOAA Sea Grant
work. Click here for a pdf of the 2004 UD Sea Grant Reporter. You can read
a recent popular article about his research in the UD
Messenger.
In the Delaware tidal river and estuary, he has conducted geophysical and
coring surveys of the bottom to map sediment types in support of both basic
and applied environmental problems, collaborating with the Delaware River Basin
Commission (DRBC) and the Delaware Department of Natural Resources and Environmental
Control (DNREC) on issues involving contaminated sediments. He
and colleague John Madsen, in the UD Geology Department, recently completed
a major survey of the upper estuary, with support from the DRBC and Delaware
Sea Grant. Please contact him for a copy of the report titled "Sedimentological
and Geophysical Survey of the Upper Delaware Estuary." Most recently,
with colleague Kuo-Chuin Wong, a physical oceanographer at the College of Marine
Studies, he has examined currents and sediment transport pathways in the estuary
using bottom-mounted sensors.
In a new Sea Grant-funded project that will begin on February 1, 2005, Sommerfield and Wong will undertake a new project, “Sediment Transport in the Delaware Estuary on Tidal and Seasonal Time Scales.”
“In March, we are initiating another measurement program of currents
and sediments in the estuary south of New Castle (sponsored by Sea Grant and
partnered with the Delaware River Basin Commission)," he says. "We don't measure
hydrocarbon in this study, but if the crude moves down-river we might run into
dribs and drabs during instrument deployments. Net (non-tidal) transport is
seaward in the spill area, so its transport to Delaware waters is very likely
indeed.”
The following is an abstract of the project:
The Delaware Estuary suffers from some of the highest levels of sediment contamination among estuaries of the Mid-Atlantic region (EPA, 1998). To predict the fate of particle-borne contaminants, it is first necessary to document the underlying processes of transport through the river-estuary system. In this study, fluxes of suspended sediment in the estuary will be examined continually for a period of nine months in 2005 using a combination of bottom-mounted sensors and periodic shipboard observations. In partnership with the Delaware River Basin Commission, the project seeks to elucidate mechanisms that moderate sediment concentrations and transport by quantifying the relative roles of river discharge, tidal currents, vertical gravitational circulation, and winds. Time series datasets of currents and sediment concentrations representative for a range of river flow and meteorological conditions will be collected and used to improve the predictive skill of extant numerical models that track particle and contaminant transport in the estuary.
Dominic Di Toro, Edward C. Davis Professor of Civil and Environmental Engineering, Department of Civil and Environmental Engineering.
Phone: (302) 831-4092 E-mail: dditoro@ce.udel.edu
Dr. Di Toro has conducted extensive research on polycyclic aromatic hydrocarbons
(PAHs) and shares these technical reports with other scientists.
Xiao-Hai Yan, Mary
A. S. Lighthipe Professor of Marine Studies, UD College of Marine Studies,
and Co-Director, UD Center for Remote Sensing. Phone: (302) 831-3694
E-Mail: xiaohai@udel.edu
Since he joined the UD faculty in 1990, Dr. Yan has pioneered the use of satellites
in tracking a range of ocean and coastal phenomena, from El Niño to
oil spills. This is a recent press
release about his research. You also can read a popular article
about his work in the UD
Messenger.
“The detection, mapping, and tracking of oil spills are of
critical importance in a wide range of emergency response activities after
a major oil spill,” he notes. “This information, along with additional
information on local environmental conditions and model output, can be used
to devise protection responses and cleanup strategies. Knowing the extent and
trajectory of an oil spill can increase the efficiency of the emergency response
effort.
“Remote sensing techniques including Synethetic Aperture Radar (SAR)
analyses and feature-tracking methods such as the maximum similarity shape
matching (MSSM) method developed here at the Center for Remote Sensing in the
University of Delaware College of Marine can help detect, map, and track oil
spills. We will collect SAR images, perform image interpretation and analysis,
and run our feature-tracking model if more than one image pair of data can
be collected,” he adds.
A detailed description of the SAR imagery, analysis method, and MSSM technique can be found in this research article published in the Journal of the Marine Technology Society.
Yan, X.-H., Pablo Clemente-Colon and William Pichel. 1997. The Maximum Similarity
Shape Matching (MSSM) feature tracking method applied to an oil spill observed
in SAR imagery. J. of Marine Technology Society (MTS Journal) 31(2):8-14.
