- 101 N Merion Ave
Bryn Mawr, PA 19010 USA - +1 610-526-5110
Donald C Barber
Bryn Mawr College, Geology and Environmental Studies, Faculty Member
- Bryn Mawr College, Department of Geology, Faculty Memberadd
- noneedit
Research Interests:
Thesis (Ph. D.)--University of Colorado, 2001. Includes bibliographical references (leaves [120]-142).
Many global processes drive coastal sea level variability, e.g., melting land-based ice, crustal subsidence due to glacial isostatic adjustment, and steric effects on sea-surface height, but the societal impacts of coastal sea level rise... more
Many global processes drive coastal sea level variability, e.g., melting land-based ice, crustal subsidence due to glacial isostatic adjustment, and steric effects on sea-surface height, but the societal impacts of coastal sea level rise are often local issues. Documentation of past and current inundation in specific areas may enhance outreach regarding the need for coastal adaptation. For example, many coastal cities now publicize "king tides" during the predicted yearly maxima of astronomical tides. Here we use tide gauge data to show increased coastal inundation in recent years. We informally define inundation episodes as times when water levels remain >10 cm above local Mean Higher High Water for one or more hours. High water during storms is nothing new for coastal residents, but fair-weather coastal flooding has become more frequent and observable. A LIDAR-generated hypsometric curve of topography shows that the most frequently flooded (lowest elevation) areas occ...
The ongoing Late Holocene sea-level rise has inundated a series of low (< 2m above sea level) relict sand ridges on Cedar Island, in southern Pamlico Sound on the central North Carolina coast (35.00°N, 76.34°W). The ridges likely... more
The ongoing Late Holocene sea-level rise has inundated a series of low (< 2m above sea level) relict sand ridges on Cedar Island, in southern Pamlico Sound on the central North Carolina coast (35.00°N, 76.34°W). The ridges likely represent shorelines formed during a previous (Pleistocene) sea-level highstand by a combination of longshore transport and eolian dune processes. Saltmarsh peat comprising primarily the remains of the high marsh plant Juncus gerardii has accumulated between the ridges, yielding a continuous record of transgression over at least the last 2,000 years. The protected depositional setting between the ridges, the small tidal amplitude (< 25 cm) in southern Pamlico Sound, and the smoothly varying topography of the underlying sand surface provide the opportunity to acquire basal saltmarsh peat samples from a range of elevations for sea-level reconstruction. We obtained cores of the marsh peat and sand deposits using various techniques (hand auger, Russian an...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
ABSTRACT Core HU97048-007PC was recovered from the NW Labrador Sea continental slope at a water depth of 945 m, 250 km seaward (ESE) from the mouth of Cumberland Sound, and 400 km northeast of Hudson Strait. Cumberland Sound is a... more
ABSTRACT Core HU97048-007PC was recovered from the NW Labrador Sea continental slope at a water depth of 945 m, 250 km seaward (ESE) from the mouth of Cumberland Sound, and 400 km northeast of Hudson Strait. Cumberland Sound is a structural trough partly floored by Cretaceous mudstones and Paleozoic carbonates. The record extends from 10 to 58 ka. Shipboard visual, magnetic and spectrophotometric logging of the core revealed a complex series of lithofacies, including buff-colored detrital carbonate-rich sediments [Heinrich (H)-events] frequently bracketed by black facies. We investigate the provenance of these facies using quantitative X-ray diffraction on drill-core samples from Paleozoic and Cretaceous bedrock from the SE Baffin Island Shelf, and on the finer-than-2-mm sediment fraction in a transect of five cores from Cumberland Sound to the NW Labrador Sea. A computational sediment unmixing program was used to discriminate between sediment sources, which included dolomite-rich sediments from Baffin Bay, calcite-rich sediments from Hudson Strait and discrete sources from Cumberland Sound. Results indicated that the bulk of the sediment was derived from Cumberland Sound, but Baffin Bay contributed to sediments coeval with H-0 (Younger Dryas), whereas Hudson Strait was the source during H-events 1–4. Contributions from the Cretaceous sedimentary outcrops within Cumberland Sound bracket H-events, thus both lead and lag Hudson Strait-sourced H-events.
Research Interests:
Research Interests:
Research Interests:
ABSTRACT
Research Interests:
Research Interests:
Research Interests:
The sensitivity of oceanic thermohaline circulation to freshwater perturbations is a critical issue for understanding abrupt climate change. Abrupt climate fluctuations that occurred during both Holocene and Late Pleistocene times have... more
The sensitivity of oceanic thermohaline circulation to freshwater
perturbations is a critical issue for understanding abrupt climate
change. Abrupt climate fluctuations that occurred during both
Holocene and Late Pleistocene times have been linked to changes
in ocean circulation, but their causes remain uncertain. One of
the largest such events in the Holocene occurred between 8,400
and 8,000 calendar years ag0 (7,650- 7,200 14C years ago), when
the temperature dropped by 4-8 °C in central Greenland1 and
1.5-3 °C at marine and terrestria sites around the northeastern North Atlantic Ocean. The pattern of cooling implies that heat transfer from the ocean to the atmosphere was reduced in the North Atlantic. Here we argue that this cooling event was forced by a massive outflow of fresh water from the Hudson Strait. This
conclusion is based on our estimates of the marine 14C reservoir
for Hudson Bay which, in combination with other regional data,
indicate that the glacial lakes Agassiz and Ojibwaf-Il (originally
dammed by a remnant of the Laurentide ice sheet) drained
catastrophically - 8,470 calendar years ago; this would have
released > 1014 m3 of fresh water into the Labrador Sea. This
finding supports the hypothesis that a sudden increase in
freshwater flux from the waning Laurentide ice sheet reduced
sea surface salinity and altered ocean circulation, thereby initiating
the most abrupt and widespread cold event to have occurred in
the past 10,000 years.
perturbations is a critical issue for understanding abrupt climate
change. Abrupt climate fluctuations that occurred during both
Holocene and Late Pleistocene times have been linked to changes
in ocean circulation, but their causes remain uncertain. One of
the largest such events in the Holocene occurred between 8,400
and 8,000 calendar years ag0 (7,650- 7,200 14C years ago), when
the temperature dropped by 4-8 °C in central Greenland1 and
1.5-3 °C at marine and terrestria sites around the northeastern North Atlantic Ocean. The pattern of cooling implies that heat transfer from the ocean to the atmosphere was reduced in the North Atlantic. Here we argue that this cooling event was forced by a massive outflow of fresh water from the Hudson Strait. This
conclusion is based on our estimates of the marine 14C reservoir
for Hudson Bay which, in combination with other regional data,
indicate that the glacial lakes Agassiz and Ojibwaf-Il (originally
dammed by a remnant of the Laurentide ice sheet) drained
catastrophically - 8,470 calendar years ago; this would have
released > 1014 m3 of fresh water into the Labrador Sea. This
finding supports the hypothesis that a sudden increase in
freshwater flux from the waning Laurentide ice sheet reduced
sea surface salinity and altered ocean circulation, thereby initiating
the most abrupt and widespread cold event to have occurred in
the past 10,000 years.
Research Interests:
Research Interests:
Research Interests:
The Challenge-(Frame and interesting question) The challenge is to summarize the development of modern estuary theory in a form that complex estuarine circulation can be derived and evaluated from simple algebraic relationships of... more
The Challenge-(Frame and interesting question) The challenge is to summarize the development of modern estuary theory in a form that complex estuarine circulation can be derived and evaluated from simple algebraic relationships of continuity of flow and continuity of mass. Example Applications-Estuarine Circulation from a salinity balance. Estuarine Dilution of river inflow constituents Sediment Transport and Settling Seasonal Temperature Distributions Naturally and with Man-Made Heat Sources Strengths and Weaknesses-Modeling Limitations Background to Modern Estuary Theory Modern estuarine dynamics theory and analysis began with Dr. Donald Pritchard at The Johns Hopkins University in the late 1950's through the 1970's and later at Stony Brooke on Long Island. Before Pritchard, estuarine analysis presented a real problem that might be stated as follows:
